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l/s/s/l 

I 


PRINCIPLES 


HUMAN   PHYSIOLOGY, 


WITH  THEIR  CHIEF  APPLICATIONS 


TO 


PSYCHOLOGY,  PATHOLOGY,  THERAPEUTICS,  HYGIENE, 
AND   FORENSIC   MEDICINE. 


BY 

WILLIAM   B.  CARPENTER,  M.D.,  F.R.S.,  F.G.S., 

nxAjr.MER  IN  PHYSIOLOGY'  AND  COMPARATIVE  ANATOMY  IN  THE  UNIVERSITY  OF  LONDON, 

OF  MK/llflAJ.  JCR1SPRPDENCE  IN  UNIVERSITY  OOU.GGE,  PRF.SIDENT 
OF  THE  MICROSCOPICAL  SOCIETY  OF  LONDON,  ETC.  ETC. 


A    N*W    AMERICAN    FROM    THE   LAST    LONDON   EDITION 

WITH  TWO   HUNDRED  AND   SIXTY-ONE   ILLUSTRATIONS 

EDITED,    WITH     ADDITIONS, 
BY 

FRANCIS  GURNEY  SMITH,  M.  D., 

JPEOFESSOR   OF   INSTITUTES   OF   MEDICINE   IN   THE   UNIVERSITY   OF   PENNSYLVANIA,    ETC 


PHILADELPHIA: 
HENRY    C.    LEA. 

1868. 


Entered,  according  to  the  Act  of  Congress,  in  the  year  1855,  toy 
BLANCHARD   &  LEA, 

in   the  Clerk's   Office   of  the  District  Court  of  the  United  States  f<r  tin  Eastern 
District  of  Pennsylvania. 


COLLINS,  PRINTER 


TO 

WILLIAM    PULTENEY  ALISON, 

M.  D.,  F.R.S.E.  Ac. 

PROFESSOR   OF    THE    PRACTICE    OF    MEDICINE    IN    THE    UNIVERSITY    OF    EDINBURGH. 


MY  DEAR  SIR, 

I  take  the  liberty  of  inscribing  the  following  Work  to  you,  as  an 
expression  of  my  grateful  remembrance  of  the  value  of  your  instructions, 
of  my  respect  for  those  Intellectual  faculties  which  render  you  pre-emi- 
nent amongst  the  Medical  Philosophers  of  our  time,  and  of  my  admira- 
tion for  those  Moral  excellences  which  call  forth  the  warm  regard  of  all 
who  are  acquainted  with  your  character. 

In  many  parts  of  this  Treatise,  you  will  find  that  doctrines  which  you 
have  long  upheld  in  opposition  to  almost  the  whole  Physiological  world, 
are  defended  with  such  resources  as  I  can  command ;  and  that,  in  several 
instances,  such  convincing  evidence  of  their  truth  has  been  afforded  by 
recent  observations,  that  further  opposition  to  them  would  now  seem 
vain.  And  if  I  have  presumed  to  differ  from  you  on  some  points,  it  has 
been  in  the  spirit  of  that  independence,  which  you  have  uniformly  en- 
couraged in  your  pupils;  yet  with  a  distrust  of  my  own  judgment,  when- 
ever it  came  into  collision  with  yours. 

That  you  may  long  be  spared  to  be  the  ornament  of  your  University, 
and  the  honour  of  your  City,  is  the  earnest  wish  of, 

Dear  Sir, 

Your  obliged  Pupil, 

WILLIAM  B.  CARPENTER. 
(iii) 


E  DI  T  OR'S   NOTICE. 


A  GLANCE  at  the  Author's  Preface  will  show  that  the  present  edition 
has  been  remodelled  to  an  extent  which  renders  it  almost  a  new  work. 
Dr.  Carpenter's  untiring  industry  has  left  little  for  the  American  editor 
to  add  beyond  an  occasional  illustration  of  the  text,  or  notices  of  more 
recent  discoveries,  which  have  been  published  since  the  issue  of  the 
English  copy.  Nearly  one  hundred  wood-engravings  have  been 
introduced  through  the  liberality  of  the  publishers  (the  greater  number 
by  the  Author  in  his  preparation  of  the  sheets  for  this  American  edition), 
by  which,  it  is  hoped,  its  value  is  greatly  enhanced.  It  is  confidently 
believed  that  the  present  will  more  than  sustain  the  enviable  reputation 
already  attained  by  former  editions,  of  being  one  of  the  fullest  and  most 
complete  treatises  on  the  subject  in  the  English  language. 

The  additional  matter  is  inclosed  in  brackets  [  ]. 

291  SPRUCE  STREET,  Sept.  1855. 


PREFACE 


NEW  AMERICAN  EDITION. 


IT  is  again  the  Author's  pleasing  duty  to  express  his  grateful  thanks 
to  his  brethren  on  the  other  side  of  the  Atlantic,  for  the  flattering  testi- 
mony which  their  very  extended  use  of  his  "Human  Physiology"  has 
borne  to  its  merits.  On  the  issue  of  the  last  Edition,  he  could  not  but 
feel  some  apprehension,  lest  the  overgrown  bulk  which  it  had  attained, 
in  consequence  of  his  desire  to  render  every  part  of  it  as  complete  as? 
possible,  might  prevent  the  continuance  of  that  general  demand,  which 
it  had  been  the  good  fortune  of  previous  Editions  to  excite.  It  has 
been,  therefore,  a  source  of  peculiar  satisfaction  to  him,  that  the  rapid 
sale  of  a  large  impression  should  have  so  promptly  renewed  the  assurance 
of  a  kind  appreciation  of  his  labours,  on  the  part  of  those  to  whom  he 
most  desires  to  render  them  acceptable.  And  the  success  which  has  thus 
attended  them,  has  been  an  additional  inducement  to  him  to  spare  no 
pains  to  deserve  a  continuance  of  it. 

In  commencing  the  preparation  of  a  New  Edition,  however,  it  was 
evident  to  him,  that,  as  the  dimensions  of  the  volume  altogether  pre- 
cluded any  increase  in  the  number  of  its  pages,  whilst  their  previous 
repletion  equally  prevented  any  augmentation  of  their  capacity,  no 
addition  of  new  matter  could  be  made,  without  a  corresponding 
omission  of  old,  —  a  proceeding  which  he  could  not  bring  himself  to 
adopt.  But  having  already  been  led,  by  the  occurrence  of  the  same 
difficulty  in  the  case  of  his  "Principles  of  General  and  Comparative 
Physiology,"  to  determine  upon  the  division  of  that  work  into  two 
separate  and  independent  Treatises,  on  "  General"  and  "  Comparative 
Physiology"  respectively,  it  seemed  to  him  to  be  the  simplest  and  most 
desirable  plan,  to  transfer  from  the  "Human"  to  the  "General  Phy- 
siology" such  parts  of  the  former  as  could  with  propriety  be  incor- 
porated with  the  latter ;  thus  effecting  such  a  reduction  in  the  size  of 

(vii) 


Vlll  PREFACE    TO    THE    NEW    EDITION. 

the  "Human,"  as  might  enable  him  to  make  any  additions  to  it  that 
the  progress  of  Science  should  require ;  and  at  the  same  time  rendering 
the  "  General"  more  comprehensive  and  complete  in  itself,  as  well  as  a 
more  appropriate  companion  either  to  the  ''Comparative"  or  to  the 
"  Human."  He  was  encouraged  to  decide  upon  this  course,  by  the 
approval  which  it  met  with  from  his  American  Publishers,  who  had 
previously  decided  upon  reprinting  his  "  General  and  Comparative  Phy- 
siology," and  who  readily  agreed  to  the  new  division  which  he  proposed; 
and  he  gladly  takes  this  opportunity  of  expressing  his  sense  of  the 
honourable  liberality  which  they  have  on  all  occasions  evinced  in  their 
arrangements  with  him,  and  his  hope  that  the  sale  of  his  "  Comparative" 
and  "  General "  Physiologies  may  be  such  as  not  to  make  them  regret 
their  spirited  determination  to  reproduce  these  as  companions  to  the 
"  Human."  These  three  books  will  henceforth  constitute  as  many 
independent  but  mutually -connected  Treatises,  on  the  three  great 
departments  into  which  modern  Physiology  naturally  divides  itself; 
and  the  Author  has  only  to  hope,  that  he  may  be  found  to  have  thus 
devised  the  most  appropriate  method  of  meeting  the  numerous  kind 
suggestions  which  have  been  made  to  him,  in  regard  to  the  division 
of  his  inconveniently-bulky  Volumes. 

In  accordance  with  the  foregoing  plan,  the  Second,  Third,  and  Fifth 
Chapters  of  the  last  Edition  of  this  work,  which  included  a  summary 
of  Animal  Chemistry,  and  of  the  Structure  and  Actions  of  the  Animal 
Tissues,  amounting  in  all  to  about  240  pages,  have  been  omitted  from  the 
present.  On  the  other  hand,  additions  have  been  made,  to  the  amount 
of  about  70  pages ;  and  these  by  no  means  constitute  the  whole  of  the 
new  matter  introduced,  since  many  portions  have  been  re-written,  with 
little  or  no  increase  of  bulk.  It  has  been  the  Author's  desire,  on  this 
as  on  former  occasions,  that  his  Treatise  should  represent  his  present 
convictions  and  opinions,  as  completely  as  if  it  were  making  its  appear- 
ance for  the  first  time ;  and  he  has  accordingly  subjected  every  part 
of  it  to  a  revision  not  less  careful  than  that  which  he  would  have 
bestowed  upon  it,  had  it  less  recently  passed  under  a  similar  scrutiny. 
Although  the  minor  results  of  this  revision,  which  are  scattered  through 
almost  every  part  of  the  volume,  would  not  be  apparent  save  on  a 
searching  comparison,  yet  he  trusts  that  they  will  be  found  to  have 
increased  the  utility  of  the  work  ;  —  those  of  more  importance,  however, 
be  deems  it  well,  now  to  particularize. 

In  the  Chapters  which  treat  of  the  several- Organic  Functions,  many 
important  additions  have  been  derived  from  the  admirable  work  of 


PREFACE    TO    THE     NEW    EDITION.  i.X 

MM.  Bidder  and  Schmidt,  u  Die  Verdauungssafte  und  der  Stoffwechsel," 
which  contains  the  results  of  those  elaborate  researches  on  Digestion, 
Respiration,  Secretion,  and  the  Metamorphosis  of  Tissue,  which  they 
have  carried-on  for  several  successive  years  in  the  Dorpat  Laboratory. 
It  may  be  thought,  perhaps,  by  such  as  are  conversant  with  this  work, 
that  the  Author  has  not  made  sufficient  use  of  the  vast  body  of  informa- 
tion which  it  supplies :  but  he  must  be  permitted  to  remark,  in  the  first 
place,  that  so  many  of  the  statements  of  these  able  Experimenters  are 
in  direct  contradiction  to  those  of  others  who  had  previously  stood  in 
good  repute,  as  well  as  to  generally-accepted  Physiological  doctrines, 
that  it  is  yet  doubtful  on  which  side  the  truth  lies ;  and,  secondly,  that 
even  where  their  facts  are  not  disputed,  there  is  often  so  much  doubt 
respecting  the  right  interpretation  of  them,  and  more  especially  in  regard 
to  their  applicability  to  Man,  that  he  has  scarcely  judged  it  expedient 
to  admit  such  into  a  Treatise  which  especially  aims  at  embodying  the 
certainties  of  Physiological  Science. 

The  portions  of  Chapter  IV.  which  relate  to  the  Glandulse  of  the 
Absorbent  System,  and  to  the  Vascular  Glands,  have  been  almost 
entirely  re-written,  in  accordance  with  the  improved  knowledge  of  these 
bodies  which  has  been  recently  attained,  through  the  labours  of  various 
histological  Anatomists  and  experimental  Physiologists,  especially 
Briicke,  Kolliker,  and  H.  Gray. 

The  part  of  Chapter  IX.  in  which  the  Minute  Anatomy  and  the  Phy- 
siology of  the  Liver  are  discussed,  has  been  brought  into  accordance, 
on  most  points,  with  the  views  entertained  by  Prof.  Kolliker  as  to  its 
structure,  and  with  those  of  Dr.  C.  Handfield  Jones  in  regard  to  its 
actions :  the  Author  being  now  convinced  that  the  account  of  this  organ 
given  by  Dr.  Leidy  and  by  Prof.  Retzius,  to  which  he  had  formerly  seen 
reason  to  assent,  is  based  on  a  wrong  interpretation  of  the  appearances 
presented ;  and  that  the  liver  really  unites,  as  well  structurally  as  func- 
tionally, the  essential  characters  of  a  Vascular  or  Assimilating  Gland, 
with  those  of  an  Excretory  Gland. 

In  Chapter  XL,  on  the  Functions  of  the  Cerebro-Spinal  Nervous 
System,  the  Author  has  again  seen  reason  to  introduce  very  considerable 
modifications ;  these  having  reference  for  the  most  part,  however,  rather 
to  the  order  of  succession  of  the  subjects,  than  to  the  opinions  previously 
put-forth,  —  the  latter,  in  fact,  having  received  most  satisfactory  confir- 
mation, alike  from  the  accordance  which  has  been  expressed  with  them 
by  many  highly-competent  judges,  from  the  Author's  own  more  matured 
reflections,  and  from  certain  occurrences  of  public  notoriety  which  have 


X  PREFACE    TO    THE    NEW    EDITION. 

afforded  most  remarkable  exemplifications  of  them.  It  would  have  been 
scarcely  possible,  in  fact,  to  conceive  of  any  more  apposite  and  con- 
vincing proof  of  that  independent  automatic  activity  of  the  Cerebrum, 
and  of  its  involuntary  influence  in  producing  Muscular  contraction,  which 
the  Author  had  formularized  in  the  doctrine  of  "Ideo-Motor  action," 
than  that  which  was  afforded  by  the  Epidemic  of  "Table-turning"  and 
"Table-talking,"  which,  originating  in  the  United  States,  began  to 
spread  through  Europe  just  at  the  epoch  of  the  publication  of  the  former 
Edition,  in  which  that  doctrine  was  first  distinctly  developed.  And  some 
of  the  rarer  phenomena  of  that  Epidemic  also  afforded  interesting  illus- 
trations of  his  doctrine  of  "Unconscious  Cerebration";  the  validity  of 
which  has  been  admitted  by  many  eminent  Psychologists,  who  have  no 
leaning  whatever  to  what  is  commonly  termed  "  Materialism."  Not 
among  the  least  valuable  of  the  testimonies  to  the  general  correctness 
of  the  Author's  views,  as  to  the  relation  of  the  Will  to  the  Automatic 
operations  of  the  Cerebrum,  are  those  which  he  has  received  from  indi- 
viduals practically  conversant  with  various  departments  of  Education 
(especially  Schools  for  the  Reformation  of  Juvenile  Delinquents),  and 
with  the  Treatment  of  Insanity.  In  recasting,  as  a  separate  Section  of 
this  Chapter,  all  that  relates  to  "  The  Mind  and  its  Operations,"  the 
Author  has  derived  many  valuable  suggestions  and  much  assistance,  in 
regard  to  the  *  Perceptive  and  Intuitional  Consciousness,'  from  the  valu- 
able "Elements  of  Psychology"  of  his  friend  Mr.  J.  D.  Morell;  whilst, 
for  the  extension  of  his  notion  of  those  states  of  feeling  which  constitute 
the  essence  of  Emotions,  from  that  of  mere  pleasure  and  pain  to  which 
he  had  previously  limited  them,  to  more  varied  forms  of  '  Emotional 
Sensibility,'  as  well  as  for  the  suggestion  of  that  very  appropriate  term, 
he  is  indebted  to  his  friend  Dr.  Daniel  Noble.1  The  whole  of  this  Sec- 
tion has  passed  under  the  revision  of  the  Rev.  W.  Thomson  (Fellow  and 
Tutor  of  Queen's  College,  Oxford),  the  Author  of  the  well-known  "  Out- 
line of  the  Necessary  Laws  of  Thought" ;  for  whose  kindness  in  under 
taking  this  labour  in  behalf  of  one  almost  a  stranger  to  him,  the  Author 
has  great  pleasure  in  making  this  acknowledgment. 

In  Chapter  XII.  (part  of  the  first  section  of  which  has  been  transferred 
to  what  seemed  its  more  appropriate  place  in  the  last-mentioned  division), 
the  section  on  Vision  has  received  several  additions  and  modifications ; 
the  most  important  of  which  are  derived  from  the  researches  of  H.  Miiller 

1  See  his  "  Elements  of  Psychological  Medicine,"  2d  edit,  p.  56.  —  This  little 
work,  the  Author  (though  not  according  in  everything  it  contains)  would  strongly 
recommend  to  all  who  are  entering  on  the  practice  of  their  Profession. 


PREFACE    TO    THE    NEW    EDITION.  XI 

on  the  Structure  of  the  Retina,  from  the  enquiries  of  Prof.  Wheatstone 
into  various  points  in  the  Physiology  of  Binocular  Vision,  and  from  the 
curious  investigations  made  by  Dr.  Serre  in  regard  to  the  subjective 
phenomena  produced  by  pressure  on  the  Eyeball. 

From  Chapter  XIII.,  also,  the  section  "  On  the  Influence  of  Expect- 
ant Attention  on  Muscular  Movements"  has  been  for  the  most  part 
removed  into  Chapter  XL,  where  it  completed  the  doctrine  of  Ideo- 
Motor  action ;  whilst  the  small  portion  relating  to  the  movements  of  the 
Organic  Muscles  has  been  transferred  to  Chapter  XV.  To  this  last 
Chapter  has  also  been  removed  the  account  of  the  structure  and  relations 
of  the  Sympathetic  System ;  so  that  it  now  embraces  a  summary  of  all 
the  principal  modes  in  which  the  Nervous  System,  or  the  Mind  through 
its  agency,  affects  the  Organic  Functions. 

Various  improvements,  scarcely  worth  here  particularizing,  have  been 
made  in  Chapter  XVI.,  on  the  Generative  Function ;  the  most  important 
additions  being  a  summary  of  Dr.  Dalton's  researches  on  the  distinctions 
between  the  Corpus  Luteum  of  simple  Menstruation  and  that  of  Preg- 
nancy, and  a  notice  of  certain  curious  circumstances  attending  the  trans- 
mission of  Parental  characters  to  the  Offspring,  which  have  a  direct 
bearing  on  the  question  of  Marriage  of  near  Relations. 

Chapter  XVIII.,  "  On  the  Modes  of  Vital  Activity  Characteristic  of 
different  Ages,"  has  been  almost  entirely  written  specially  for  this  Edi- 
tion ;  the  subject,  which  had  been  only  touched-on  incidentally  in  the 
preceding,  appearing  to  the  Author  to  deserve,  under  every  point  of 
view,  a  more  express  consideration. 

The  entire  number  of  Wood-Engravings  has  necessarily  undergone 
some  reduction,  owing  to  the  transference  of  no  fewer  than  82,  which 
illustrated  the  structure  of  the  Primary  Tissues,  to  the  "  General  Phy- 
siology." But  as  many  as  46  new  ones  have  been  introduced,  in  addi- 
tion to  those  which  previously  illustrated  the  subjects  treated-of  in  the 
present  volume ;  these  having  been  for  the  most  part  drawn  from  the 
"  Mikroskopische  Anatomic"  of  Prof.  Kolliker,  and  from  the  new  edition 
of  Prof.  Wagner's  "  Icones  Physiologies"  now  being  brought-out  under 
the  able  superintendence  of  Prof.  Ecker.1 

1  It  is  the  Author's  ambition  to  produce,  when  his  other  engagements  may  permit, 
a  similar  original  work,  that  shall  do  like  credit,  he  trusts,  to  British  Science.  For 
the  present,  however,  all  his  disposable  time  must  be  given  to  the  completion  of  cer- 
tain literary  undertakings,  among  which  the  "  General  Physiology"  will  rightly  claim 
his  early  attention  ;  and  to  preparing  for  publication  a  series  of  original  researches 
in  another  department  of  Biological  Science,  on  which  he  has  been  for  some  time 
engaged. 


Xll  PREFACE    TO    THE    NEW    EDITION. 

The  Ai'th^r  trusts  that  it  will  be  apparent,  from  the  foregoing  sum- 
mary, that  he  has  spared  no  pains  to  render  the  present  Edition  worthy 
of  the  favourable  reception  which  has  been  accorded  to  its  predecessors. 
In  making  his  selection  from  the  vast  mass  of  results  which  have  been 
recently  accumulated  by  the  diligent  labours  of  Physiologists  of  various 
countries,  he  has  been  guided  by  the  principle  which  he  had  previously 
expressed  on  several  occasions  : — that,  namely,  of  not  rashly  introducing 
changes  inconsistent  with  usually-received  views ;  —  nor,  on  the  other 
hand,  showing  an  unwillingness  to  adopt  the  statements  of  those  who 
have  taken  adequate  pains  to  arrive  at  accurate  conclusions.  "  He  trusts 
that  he  may  be  found" — now,  as  then — "to  have  exercised  a  sound 
discretion,  as  to  both  what  he  has  admitted,  and  what  he  has  rejected ; 
and  that  his  work  will  appear  to  exhibit,  on  the  whole,  a  faithful  reflec- 
tion of  the  present  aspect  of  Physiological  Science.  He  cannot  venture 
to  expect,  however,  that  he  has  succeeded  in  every  instance,  so  that  each 
of  his  readers  will  be  in  constant  agreement  with  him ;  since  it  is  im- 
possible that  they  should  all  survey  the  subject  from  the  same  point 
of  view." 

In  conclusion,  the  Author  would  repeat  the  remark  with  which  he 
brought  to  a  close  the  Preface  to  the  first  Edition  (1842) :  —  "  that  in 
a  work  involving  many  details,  it  is  not  to  be  expected  that  no  error 
should  have  crept-in ;  but  that  he  has  endeavoured  to  secure  correctness, 
by  relying  only  upon  such  authorities  as  appeared  to  him  competent, 
and  by  comparing  their  statements  with  such  general  principles  as  he  con- 
sidered well  established.  For  the  truth  of  those  principles  he  holds  himself 
responsible ;  for  the  correctness  of  the  details,  he  must  appeal  to  those 
from  whom  they  are  derived,  and  to  whom  he  has  generally  referred. 
He  hopes  that  he  may  not  be  found  unwilling  to  modify  either,  when 
they  have  been  proved  to  be  erroneous ;  nor  indisposed  to  profit  by 
criticism,  when  administered  in  a  friendly  spirit." 

UNIVERSITY  HALL,  London,  March,  1855. 


TABLE   OF   CONTENTS 


CHAPTER  I. 

PASS 

OF  THE  DISTINCTIVE  CHARACTERISTICS  OF  MAN  ...........................  i  ....................     33 


CHAPTER   II. 

GENERAL   VIEW   OF   THE    FUNCTIONS    OF   THE    HUMAN   BODY. 

1.  Of  the  Mutual  Dependence  of  its  Vital  Actions  ..............................................      46 

2.  Functions  of  Vegetative  Life  .....................  .................................................     50 

3.  Functions  of  Animal  Life  ...........................................................................     68 

CHAPTER    III. 

OF    FOOD   AND    THE   DIGESTIVE   PROCESS. 

1.  Of  Food  and  Drink,  their  Nature  and  Destination  .......................  ,  ..........  .,.,..  ..     63 

2.  Of  Hunger  and  Thirst  ;  Starvation  ...............................................................     80 

3.  Movements  of  the  Alimentary  Canal  ...................................................  .  ........     86 

Prehension  and  Ingestion  ......................................................................  86 

Mastication  ........................................................................................  87 

Deglutition  ........................................................................................  90 

Movements  of  the  Stomach  ..................................................................  94 

Peristaltic  Movement  of  Intestines  ......................  r  ..................................  97 

Defecation  .................................  .......................................................  99 

4.  Of  the  changes  which  the  Food  undergoes,  during  its  passage  along  the  Alimentary 

Canal  ...................................................................................................  100 

Salivary  Secretion,  and  Buccal  Digestion  ................................................  100 

Gastric  Juice,  and  Gastric  Digestion  ..................  .....................................  104 

Pancreatic,  Biliary,  and  Intestinal  Secretions  ;  Intestinal  Digestion  ..............  ,  120 

CHAPTER  IV. 

OF   ABSORPTION   AND    SANGUIFICATION, 

1.  Of  Absorption  from  the  Digestive  Cavity;  Intestinal  Villi  ................................   133 

2.  Absorption  from  the  Body  in  General  ..........................................................  146 

(xiii) 


X.V  CONTENTS. 

PAGE 

3.   Of  the  Elaboration  of  the  Nutrient  Materials 150 

Assimilating  action  of  Liver 151 

Assimilating  action  of  Absorbent  System 152 

Composition  and  Properties  of  Chyle  and  Lymph 155 

Vascular  or  Ductless  Glands 159 


CHAPTER   Y. 

OF     THE     BLOOD ;     ITS    PHYSICAL     CHARACTERS,     CHEMICAL     COMPOSITION,    AND    VITAL 

PROPERTIES. 

1.  General  Considerations: — Quantity  of  Blood 169 

2.  Of  the  Physical,  Chemical,  and  Structural  Characters  of  the  Blood 171 

Corpuscular  Elements  of  Blood 173 

Chemical  Composition  of  the  Blood 185 

Alterations  of  Composition  in  Disease 199 

8.   Of  the  Vital  Properties  of  the  Blood,  and  its  Relations  to  the  Living  Organism. ...  206 

Coagulation  of  the  Blood 207 

Relation  of  the  Blood  to  the  Nutritive  Processes 223 

Relation  of  the  Blood  to  Morbid  Actions ,    ..  232 


CHAPTER  YI 

OP   THE   CIRCULATION    OF   THE    BLOOD. 

1.  Of  the  Circulation  in  General 23^ 

2.  Action  of  the  Heart 241 

Source  of  its  Rhythmical  Movements 241 

Succession  of  its  Actions 248 

Sounds  of  the  Heart 251 

Rate  and  Force  of  its  Pulsations 253 

a.  Movement  of  the  Blood  in  the  Arteries 258 

4    Movement  of  the  Blood  in  the  Capillaries 266 

5.  Movement  of  the  Blood  in  the  Veins 275 

6.  Peculiarities  of  the  Circulation  in  different  Parts ..  278 


CHAPTER  VII. 

OF   RESPIRATION. 

1  Nature  of  the  Function,  and  Provisions  for  its  Performance 280 

Sources  of  Production  of  Carbonic  Acid  in  the  Living  Body , 281 

Structure  of  the  Lungs 282 

Respiratory  Movements 288 

2.  Effects  of  Respiration  on  the  Air 298 

Exhalation  and  Absorption  through  the  Lungs 310 

3  Effects  of  Suspension  or  Deficiency  of  Respiration 314 

Asphyxia 314 

Predisposition  to  Zymotic  Diseases 317 


CONTENTS.  XV 


CHAPTER  VIII. 

OF   NUTRITION. 

1AGB 

j.  General -Considerations. — Formative  Power  of  Individual  Parts 327 

Degeneration  and  Disintegration 329 

2.  Varying  Activity  of  the  Nutritive  Processes 337 

Hypertrophy;  Tumours , 338 

Atrophy 341 

Reparative  Process 343 

3.  Abnormal  Forms  of  the  Nutritive  Process 349 

Inflammation 349 

Tuberculosis 355 

Cancer...                 357 


CHAPTER    IX. 

OP    SECRETION   AND    EXCRETION. 

1.  Of  Secretion  in  General 357 

Excretory  Operations 358 

Metastasis  of  Secretion 368 

2.  The  Liver. — Secretion  of  Bile 366 

Structure  and  Actions  of  the  Liver 366 

Composition  and  Sources  of  Bile 377 

3.  The  Kidneys. — Secretion  of  Urine 381 

Structure  and  Actions  of  the  Kidneys 381 

Composition  and  Sources  of  Urine 389 

4.  The  Skin. — Cutaneous  Transpiration 401 

Structure  of  Sudoriparous  Glandulse 401 

Sudoriparous  Excretion 402 


CHAPTER  X. 

OF   THE    EVOLUTION   OF   HEAT,    LIGHT,    AND   ELECTRICITY. 

1.  General  Considerations 405 

2.  Evolution  of  Heat 40f. 

Temperature  of  the  Human  Body *07 

Sources  of  Calorifying  Power 412 

Power  of  Frigorification 420 

3.  Evolution  of  Light 42. 

4.  Evolution  of  Electricity 422 

Muscular  Current 423 

Nervous  Current ,    ..  427 


XVI  CONTENTS. 


CHAPTER   XI. 

OF    THE    FUNCTIONS    OF    THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

PAGE 

1.   General  Summary 430 

Cerebro-Spinal  Nervous  Centres 431 

Cerebro-Spinal  Nerve-trunks 432 

Determination  of  the  Functions  of  Nerves 444 

2    Of  the  Spinal  Axis  (Spinal  Cord  and  Medulla  Oblongata) 448 

Structure  and  Relations  of  the  Spinal  Cord 448 

Structure  and  Relations  of  the  Medulla  Oblongata.... 455 

Nerves  of  the  Spinal  Axis 461 

Functions  of  the  Spinal  Axis: — Excito-Motor  Actions 472 

8    Of  the  Sepeory  Ganglia 488 

Structure  and  Relations  of  the  Sensory  Ganglia 488 

Nerves  of  Special  and  Common  Sensation 491 

Functions  of  the  Sensory  Ganglia:  Sensori-Motor  Actions 495 

Muscular  Sense 505 

4.  Of  the  Cerebellum 511 

Structure  and  Relations  of  the  Cerebellum 511 

Functions  of  the  Cerebellum. — Co-ordination  of  Muscular  Action 517 

"  "  Supposed  relation  to  Sexual  Propensity 517 

5    Of  the  Cerebrum..... 522 

Structure  and  Relations  of  the  Cerebrum 528 

Functions  of  the  Cerebrum. — Intelligence  as  contrasted  with  Instinct 530 

6.  Of  the  Mind,  and  its  Operations 537 

Correlation  of  Physiological  and  Psychical  action 537 

Sensational  Consciousness 545 

Perceptive  and  Intuitional  Consciousness 554 

Ideational  Consciousness 559 

Emotional  Consciousness 566 

Succession  of  Psychical  States 572 

Laws  of  Association 575 

Intellectual  Faculties 580 

Unconscious  Cerebration 589 

Ideo-Motor  Actions: — Expectant  Attention 589 

Determining  Power  of  Volition ;....  596 

Its  suspension  in  state  of  Abstraction,  and  in  Spontaneous  and  Induced 

Reverie 600 

Volitional  Control  over  succession  of  Mental  States 604 

Motive  Powers 606' 

7  Of  Sleep  and  its  Allied  States 609 

Dreaming 616 

Somnambulism,  spontaneous  and  induced 618 

Mesmerism 620 

8  General  Recapitulation,  and  Pathological  Applications 623 

Normal  Modes  of  Cerebral  Activity 624 


CONTENTS.  Xvil 

PAGE 

Abnormal  Modes  of  Cerebral  Activity 625 

Delirium 625 

Mania  and  Insanity 627 

Hysteria 633 

False  Perceptions;  Delusions 634 

Chorea 635 

Independent  Activity  of  Sensori-Motor  Centres 637 

Abnormal  Modes  of  Sensori-Motor  Activity 640 

Spectral  Illusions , 641 

Paralysis,  Vertigo,  and  Epilepsy 642 

Normal  Functions  of  SpinaVAxis 644 

Abnormal  Actions  of  Spinal  Axis 644 

Convulsive  Disorders 644 

Paralysis 648 


CHAPTER    XII. 

OP  SENSATION,  AND  THE  ORGANS  OF  THE  SENSES. 

\.  Of  Sensation  in  General 349 

2.  Sense  of  Touch 652 

3.  Sense  of  Taste 658 

4.  Sense  of  Smell 665 

5.  Sense  of  Vision 667 

6.  Sense  of  Hearing 690 

CHAPTER  XIII. 

OP   MUSCULAR   MOVEMENTS. 

1.  Voluntary  and  Involuntary  Movements 706 

2.  Symmetry  and  Harmony  of  Muscular  Movements 708 

Movements  of  the  Eye;  Strabismus 710 

3.  Energy  and  Rapidity  of  Muscular  Contraction 714 

CHAPTER  XIV. 

OF    THE   VOICE    AND   SPEECH. 

1.  Of  the  Larynx  and  its  Actions 717 

2.  Of  Articulate  Sounds 727 

Stammering 731 

CHAPTER  XV. 

OF   THE   INFLUENCE    OF   THE    NERVOUS    SYSTEM   ON    THE    ORGANIC   FUNCTIONS. 

1.  Sympathetic  Nervous  System;  its  Structure  and  Relations 733 

2.  Influence  of  Nervous  Agency  and  of  Mental   States  on  Contraction  of  Organic 

Muscles 738 

8.  Influence  of  Nervous  Agency  and  of  Mental  States  on  Nutrition  and  Secretion....  739 
2 


XV111  CONTENTS. 

CHAPTER  XVI. 

OF   GENEBATION. 

PAGB 

1.  General  Character  of  the  Function 746 

2.  Action  of  the  Male 748 

Structure  of  Testes.— Spermatic  Fluid 748 

Coitus;  Emissio  Seminis 752 

8.  Action  of  the  Female 753 

Structure  of  Ovary,  Ovisac,  and  Ovum 753 

Puberty;  Menstruation 755 

Maturation  of  Ova;  Corpus  Luteum 758 

Fecundation  of  Ovum 762 

Formation  of  Decidua 765 

Formation  of  Placenta 768 

Parturition;  Duration  of  Gestation 773 

4.  Development  of  the  Embryo 783 

6.  Of  Lactation 813 


CHAPTER  XVII. 

Or  THE  DIFFERENT  BRANCHES  OF  THE  HUMAN  FAMILY,  AND  THEIR  MUTUAL  RELATIONS. 

1    General  Considerations ;  Differentiation  of  Species 824 

2.  General  Survey  of  the  Principal  Families  of  Mankind 836 


CHAPTER  XVIII. 

OP   THE   MODES   OF   VITAL   ACTIVITY   CHARACTERISTIC    OF   DIFFERENT   AGES. 

ju  General  Considerations;  Germinal  Capacity 84i 

2.  Period  of  Growth  and  Development 850 

3.  Period  of  Maturity 861 

4.  Period  of  Decline....  ..  862 


CHAPTER  XIX. 
OF  DEATH 86* 


EXPLANATION    OF  PLATES. 


PLATE   I. 

no. 

1.  Spermatozoa  of  Man;  A,  viewed  on  the  surface;  B,  viewed  edgeways  (|  843). 

2.  Vesicles  of  evolution  from  the  seminal  fluid  of  the  Dog ;  A,  B,  c,  single  vesicles  of 

different  sizes ;  D,  single  vesicle  within  its  parent-cell ;  E,  parent-cell  enclosing 
seven  vesicles  of  evolution  ($  844). 

3.  Development  of  Spermatozoa  within  the  vesicles  of  evolution  ;  A,  B,  vesicles  contain- 

ing spermatozoa  in  process  of  formation;  c,  D,  spermatozoa  escaping  from  the 
vesicles  (§  844). 

[The  three  preceding  figures   are   after  Wagner  and   Leuckardt  ("  Cyclop,   of 
Anatomy  and  Physiology,"  Art.  'Semen').] 

4.  Thin  slice  of  the  ovarium  of  a  Sow  three  weeks  old,  showing  the  Graafian  vesicles  or 

ovisacs  imbedded  in  a  fibro-cellular  stroma.  The  ovisacs  are  filled  with  cells, 
in  the  midst  of  which  one  large  one  may  be  specially  distinguished ;  this,  which 
is  the  germinal  vesicle,  is  surrounded  by  minute  granules,  which  constitute  the 
first  indication  of  the  yolk  ($  850). 

5.  Ovum  of  a  Rabbit,  showing  the  vitelline  mass  almost  entirely  converted  into  distinct 

cells,  of  which  those  at  the  surface  are  pressed  against  each  other  and  against 
the  zona  pellucida,  so  as  to  assume  a  hexagonal  form.  The  dark  portion  con- 
sists of  a  mass  of  vitelline  spheres,  which  has  not  undergone  this  conversion 
(2  888). 

6.  Ovum  of  the  Rabbit,  seven  days  after  impregnation,  viewed  on  a  black  ground.     The 

outer  membrane  is  the  chorion,  on  which  are  seen  incipient  villosities.  Within 
this  is  the  blastodermic  vesicle,  at  the  summit  of  which  is  the  projection  formed 
by  the  area  germinativa  ;  and  from  this,  the  mucous  layer  of  the  germinal  mem- 
brane is  seen  to  extend  over  about  one-third  of  the  surface  of  the  contained  yolk 


7.  Portion  of  the  germinal  membrane,  taken  from  the  area  germinativa,  to  show  the  two 

layers  of  which  it  is  composed ;  the  serous,  or  animal  layer,  is  turned  back,  so 
as  to  show  the  mucous  or  vegetative  layer  in  situ.  In  the  latter  is  seen  the  primi- 
tive trace  (I  888). 

8.  Portion  of  the  serous  layer  of  the  germinal  membrane,  highly  magnified ;  showing  that 

it  is  made-up  of  nucleated  cells,  united  by  intercellular  substance,  and  filled 
with  minute  molecules  (§  888). 

9.  Portion  of  the  mucous  layer  of  the  germinal  membrane,  highly  magnified ;  showing 

that  it  is  made-up  of  cells,  whose  borders  are  more  distinct  and  more  closely 
applied  to  each  other  than  those  of  the  serous  layer,  and  whose  contents  are 
more  transparent  (§  888). 
[The   six   preceding   figures  are  after   Bischoif   ("Entwickelungsgeschichte   der 

Saugethiere,"  &c.  (1842),  — "des  Kaninchen-eies  "  (1842),  —  "des  Hunde- 

eies"  (1845).] 


XX  EXPLANATION    OF    PLATES. 

FIG. 

10.  Gravid  Uterus  of  a  Woman  -who  had  committed  suicide  in  the  seventh  week  of  preg- 
nancy, laid  open ;  a,  os  uteri  internum  ;  5,  cavity  of  the  cervix ;  c,  c,  c,  c,  the  four 
flaps  of  the  body  of  the  uterus  turned  back ;  d,  d,  d,  inner  surface  of  uterine 
decidua ;  e,  e,  decidua  reflexa ;  /,  /,  external  villous  surface  of  the  chorion :  g, 
internal  surface  of  the  chorion;  h,  amnion ;  i,  umbilical  vesicle;  k,  umbilical 
cord ;  I,  embryo ;  m,  space  between  chorion  and  amnion  (|g  862-864,  and  890, 
891.)  [After  Wagner  ("  Icones  Physiologies  ").] 


PLATE  II. 

11.  Uterine  Ovum  of  Rabbit,  showing  the  Area  Pellucida,  with  the  primitive  trace 

(8  889). 

12.  More  advanced  Ovum,  showing  the  incipient  formation    of  the  Vertebral    column, 

and  the  dilatation  of  the  primitive  groove  at  its  anterior  extremity  (g  889). 

13.  More  advanced  Embryo,  seen  on  its  ventral  side,  and  showing  the  first  development 

of  the  Circulating  apparatus.  Around  the  Vascular  Area  is  shown  the  terminal 
sinus,  a,  a,  a.  The  blood  returns  from  this  by  two  superior  branches,  b,  b,  and 
two  inferior,  e,  c,  of  the  omphalo-mesenteric  veins,  to  the  heart,  d ;  which  is,  at 
this  period,  a  tube  curved  on  itself,  and  presenting  the  first  indication  of  a 
division  into  cavities.  The  two  aortic  trunks  appear,  in  the  abdominal  region, 
as  the  inferior  vertebral  arteries,  e,  e;  from  which  are  given-off  the  omphalo- 
mesenteric  arteries,  /,  /,  which  form  a  network  that  distributes  the  blood  over 
the  vascular  area.  In  the  cephalic  region  are  seen  the  anterior  cerebral  veBi- 
cles,  with  the  two  ocular  vesicles,  g  (\\  890,  892). 
[The  three  preceding  figures  are  from  the 'works  of  Bischoff  previously  cited  \ 


LIST   OF   WOOD-ENGRAVINGS- 


FIQ.  PAGE 

1.  Hand  of  Man,  compared  with  anterior  extremity  of  Orang;  after  Gervais 33 

2.  Base  of  Skull  of  Man,  compared  with  that  of  Orang;  after  Owen 35 

3  and  4.   Occipital  Condyles  of  Caucasian  and  African;  after  Neill 36 

5.  Skeleton  of  Gorilla ;  after  Gervais 37 

6.  Comparative  view  of  Skeleton  of  Man,  and  Orang  Outang 38 

7.  Foot  of  Man,  compared  with  posterior  extremity  of  Orang;  after  Gervais 40 

8.  Vertical  Section  of  Skull  of  Adult  Orang;  after  Owen 41 

9.  Vertical  Section  of  Skull  of  Young  Orang;  after  Owen 41 

10.  Vertical  Section  of  Skull  of  Papuan  Negrito;  after  Owen 41 

11.  View  of  the  Organs  of  Digestion  in  their  whole  length 88 

12.  Muscles  of  the  Tongue,  Palate,  Larynx  and  Pharynx 89 

13.  Front  view  of  Stomach,  distended 93 

14.  Interior  of  Stomach 94 

15.  Interior  of  Stomach  and  Duodenum 95 

16.  Lobule  of  Parotid  Gland  of  Infant ;  after  Wagner 100 

17.  Capillary  network  around  follicles  of  Parotid  ;  after  Berres 100 

18.  Vertical  Section  of  Mucous  Membrane  of  Stomach  ;  after  Wagner 104 

19.  Capillary  network  of  Stomach,  with  orifices  of  gastric  follicles;  after  Kolliker...  104 

20.  Peptic  Gastric  gland  ;  after  Kolliker 105 

21.  Portion  of  ditto,  more  highly  magnified;  after  Kolliker 105    / 

22.  Transverse  section  through  cluster  of  gastric  caeca;  after  Kolliker 106 

23.  Mucous  Gastric  gland;  after  Kolliker , 106 

24.  Horizontal  section  of  a  Stomach-cell,  a  little  way  within  its  orifice  106 

25.  Capillaries  of  lining  membrane  of  Stomach,  showing  rudimentary  villi  and  orifices 

of  follicles  :  original ..« 106 

26.  Tubular  follicle  of  Pig's  Stomach  ;  after  Wasmann 107 

27.  Mucous  Membrane  of  Stomach ;  after  Wilson 107 

28.  Portion  of  Brunner's  Gland  ;  after  Allen  Thomson 127 

29.  Mucous  Membrane  of  Jejunum;  after  Wilson 129 

30.  Portion  of  free  border  of  Valvulse  Conniventes,  showing  Alveolar  and  Glandular 

Structure;  after  Wilson 129 

31.  Mucous  Membrane  of  large  Intestine ;  after  Wilson 129 

32.  Villi  of  Human  Intestine,  injected ;  after  Kolliker 133 

33.  Inverted  Section  of  Ileum 134 

34.  Vessels  of  Intestinal  Villus  of  a  Hare 134 

35.  Extremity  of  Intestinal  Villus,  during  absorption,  and   in   the   interval ;    after 

Goodsir 135 

36.  Extremity  of  Intestinal  Villus,  during  absorption;  after  Kolliker 136 

37.  Section  of*    :iiall  Intestine,  showing  Glands  of  Peyer 152 

d8.  A.   Portion  of  a  Peyerian  patch ;  after  Boehm 153 

38.  B.   Peyerian  glandular,  more  highly  magnified;  after  Allen  Thomson 153 

39.  Vertical  Section  of  Peyerian  Glandules  ;  after  Allen  Thomson 153 

40.  Distribution  of  Blood-vessels  in  Peyerian  Glandulse ;  after  Kolliker 154 

41.  Section  of  Lymphatic  Gland:  after  Kolliker 154 

42.  Chyle-corpuscles  in  various  phases;  after  Kolliker 156 

43.  Sympathetic  Heart;  after  Miiller 157  . 

44.  Malpighian  Corpuscles  attached  to  Splenic  Artery ;  after  Kolliker 160 

45.  Thymus  Gland  at  eighth  month;   after  Cooper 163  ! 

46.  Portion  of  Thymus  of  Calf,  unfolded;  after  Kolliker 164 

47.  Section  of  Human  Thymus;  after  Kolliker 164 

48.  Section  through  lobule  of  Thymus ;   after  Kolliker 165 

49.  Gland-vesicles  of  Thyroid;  after  Kolliker 165 

50.  Red  Corpuscles  of  Human  Blood;  after  Donne" 173 

51.  Red  Corpuscles  of  Ox 173 

52.  Red  Corpuscles  of  Pigeon 174 

53.  Corpuscles  of  Frog's  Blood ;   after  Wagner 174 

54.  Arrangement  of  Corpuscles  in  coagulating 178 

55.  Colourless  Corpuscles  of  Human  Blood ;   after  Kolliker 179 

56.  Small  venous  trunk,  from  Frog's  foot;  after  Wagner 180 


LIST    OF    WOOD-ENGRAVINGS. 

FIG.  PACT 

57.  Development  of  the  first  set  of  Ked  Corpuscles  in  the  blood  of  the  Batrachian 

Larva 181 

58.  Blood-corpuscles   of  fo3tal    Lamb,    undergoing   duplicative    subdivision ;    after 

Kolliker 182 

59.  Development  of  Human  Lymph  and  Chyle-corpuscles  into  Red  Corpuscles  of  the 

Blood 183 

60.  Phases  of  Human  Blood-corpuscles 184 

61.  Blood-crystals  ;  after  Funke 187 

62.  Splenic  blood-corpuscles,  with  rod-like  crystals  ;  after  Kolliker ,....   197 

63.  Microscopic  appearance  of  Inflammatory  Blood ;  after  Addison 214 

64.  The  Anatomy  of  the  Heart 250 

65.  Hsemadynamometer  of  Poisseuille 256 

66.  Blood-vessels  of  web  of  Frog's  foot ;  after  Wagner 258 

•        67.   Hsemodrometer  of  Volkmann 264 

68.  Capillary  plexus  of  Frog's  foot,  more  highly  magnified  ;  after  Wagner 264 

69.  Capillary  Blood-vessels  from  Pia  Mater ;  after  Henle" 267 

70.  Distribution  of  Capillaries  in  Skin  of  Finger:  after  Berres 268 

71.  Do.  around  follicles  of  Mucous  Membrane ;  after  Berres..  268 

72.  Do.  in  Muscle;  after  Berres 268 

73.  Do.  around  Fat-cells 268 

74.  Lung  of  Triton,  slightly  magnified :  after  Wagner 283 

75.  Portion  of  the  same,  more  highly  magnified;  after  Wagner 283 

76.  Capillary  Circulation  in  Lung  of  living  Triton  :  after  Wagner 283 

77.  Small  bronchial  Tube,  laid  open;  after  Todd  and  Bowman 284 

78.  Air-cells  of  Human  Lung ;  after  Kolliker 285 

79.  Capillaries  and  Air-cells  of  Human  Lung  ;  original 285 

80.  Slice  from  pleural  surface  of  Cat's  lung ;   after  Rossignol 286 

81.  Bronchial  termination  in  lung  of  Dog ;  after  Rossignol 286 

82.  Type  of  respiration  in  Female 288 

83.  Do.  Do.        in  Male 288 

84.  Transverse  section  of  compact  Bone,  showing  Haversian  space;  after  Tomes....  334 

85.  The  same,  from  less  compact  Bone  ;  after  Tomes 334 

86.  Transverse  section  of  Bone,  showing  new  Haversian  system  within  older  one ; 

after  Tomes 335 

87.  Softening  Fibrine  from  vein  clot ;  after  Sieveking  and  Jones 336 

88.  Fat  in  Blood;  after  Sieveking  and  Jones 336 

89.  Fibres  of  healthy  Fibrine ;  after  Sieveking  and  Jones 353 

90.  Corpuscular  unhealthy  Fibrine  ;  after  Sieveking  and  Jones 353 

91.  Gray  Tubercle;  after  Sieveking  and  Jones 356 

92.  Yellow  Tubercle ;  after  Sieveking  and  Jones 356 

93.  Cancer  Cells;  after  Sieveking  and  Jones 357 

94.  Plan  of  extension  of  Secreting  Membrane 358 

95.  Lobule  of  Liver  of  Squilla  Mantis 366 

96.  Hepatic  csecum  of  Cray-fish  ;  after  Leidy 367 

97.  Inferior  surface  of  Liver 368 

98.  Connection  of  lobules  of  Liver  with  Hepatic  Vein:  after  Kiernan 368 

99.  Plan  of  arrangement  of  Blood-vessels  in  lobules  of  Liver;  after  Kiernan 369 

100.  Section  of  lobules,  showing  distribution  of  intralobular  veins :  after  Kiernan....  370 

101.  Horizontal  section,  showing  intralobular  Biliary  Ducts  ;  after  Kiernan 370 

102.  Diagram  of  arrangement  of  cellular  Parenchyma  of  Liver ;  after  Kolliker 370 

103.  Transverse  section  of  a  lobule,  showing  reticular  arrangement  of  its  paren- 

chyma; after  Leidy 371 

104.  Portion  of  the  same,  more  highly  magnified;  after  Leidy 371 

105.  Portion  of  Hepatic  column,  with  secreting  cells;  after  Leidy 372 

106.  Lobules  of  Liver  in  a  state  of  Anaemia;  after  Kiernan 373 

107.  Do.  in  first  stage  of  Hepatic  Venous  Congestion  ;  after  Kiernan  ...  373 

108.  Do.  in  second  stage  of  Hepatic  Venous  Congestion  ;  after  Kiernan.  374 

109.  Do.  in  a  state  of  Portal  Venous  Congestion  ;  after  Kiernan 374 

110.  Hepatic  Cells  gorged  with  Fat;  after  Bowman 375 

111.  Cholesterine 377 

112.  Section  of  Cortical  Substance  of  Kidney ;  after  Ecker 382 

113.  Section  of  Kidney  of  new-born  Infant ;  after  Wagner 382 

114.  Portion  of  Tubulus  Uriniferus,  with  secreting  cells:  after  Wagner 382 

115.  Small  portion  of  injected  Kidney,  highly  magnified:  after  Wagner 383 

116.  Structure  of  Malpighian  body  ;  after  Bowman 384 

117.  Diagram  of  the  Circulation  in  the  Kidney  ;  after  Bowman 386 


LIST    OF    WOOD-ENGRAVINGS.  XXlll 

FIO  PAGB 

118.  Sudoriparous  gland,  with  its  duct;  after  Wagner 402 

119.  Lining  Membrane  of  perspiratory  tubes ;  after  Wilson 40E 

120.  Arrangement  of  apparatus  to  exhibit  the  Nervous  Current  of  Electricity ;  after 

Du  I3ois-Reymond , , 427 

121.  Do.  do.  do 428 

(22.  Microscopic  Ganglion  from  Heart  of  Frog  ;  after  Ecker 431 

123.  Bipolar  Ganglionic  cells  and  nerve-fibres ;  after  Ecker 431 

124.  Stellate  Ganglionic  cell;  after  Ecker 431 

125.  Brain  of  Cod;  after  Leuret 438 

126.  Magnified  view  of  Transverse  Section  of  Spinal  Cord;  after  J.  L.  Clarke 449 

127.  Transverse  Sections  of  Spinal  Cord  at  different  points;  after  Solly 450 

128.  Longitudinal  Section  of  Spinal  Cord;  after  J.  L.  Clarke 451 

129.  Anterior  view  of  Medulla  Oblongata 455 

130.  Posterior  view  of         do.  do 455 

131.  Dissection  of  Medulla  Oblongata ;  after  Solly  (altered) 456 

132.  Transverse  section  of  Medulla  Oblongata 457 

133.  Course  of  the  Motor  tract  in  the  Medulla  Oblongata;  after  Sir  C.  Bell 458 

134.  Course  of  the  Sensory  tract  in  the  Medulla  Oblongata;  after  Sir  C.  Bell 460 

135.  View  of  posterior  part  of  Cord 460 

136.  Nerves  of  the  Orbit;  after  Arnold 463 

137.  Distribution  of  Facial  nerve ;  after  Erasmus  Wilson 464 

138.  Diagram  of  Distribution  of  Eighth  Pair;  after  Erasmus  Wilson 467 

139.  View  of  Distribution  of  Glosso-pharyngeal 467 

140.  Course  and  Distribution  of  Hypoglossal 469 

141.  Cerebral  connection  of  the  Cerebral  nerves 471 

142.  Section  of  Cerebrum;  after  Solly 489 

143.  View  of  second  Pair,  or  Optic 492 

144.  Chiasmaof  Optic  Nerve 493 

145.  Origin  and  Distribution  of  Portio  Mollis,  Seventh  Pair 494 

146.  Under  view  of  Cerebellum,  from  behind 512 

147.  Analytical  diagram  of  Encephalon  in  a  vertical  section 512 

148.  Connection  between  Motor  tracts  and  Cerebellum 513 

149.  Diagram  of  mutual  relations  of  principal  Encephalic  centres  ;  original 524 

150.  Course  and  Connection  of  fibres  of  Corpus  Callosum 526 

151.  Course  of  fibres  of  Superior  Longitudinal  Commissure 527 

152.  Relations  of  the  Fornix 528 

153.  Vertical  section  of  Skin,  showing  distribution  of  nerves;  after  Ecker 653 

154.  Tactile  corpuscles  of  cutaneous  papillae  ;  after  Ecker 653 

155.  Capillary  net- work  at  margin  of  lips ;  after  Berres 654 

156.  Dorsal  surface  of  Tongue ;  after  Soemmering 660 

157.  Simple  papillae  near  base  of  Tongue;  after  Todd  and  Bowman 660 

158.  Compound  and  simple  papillae  of  Foramen  Caecum;  after  Todd  and  Bowman....  661 

159.  Vertical  section  of  a  Circumvallate  papilla ;  after  Todd  and  Bowman 661 

160.  Fungiform  papilla,  with  secondary  papillae 661 

161.  Capillary  net-work  of  fungiform  papilla  of  Tongue ;  after  Berres 662 

162.  Various  forms  of  Conical  papillae , 662 

163.  Fibres  of  Olfactory  nerve ;  after  Ecker 665 

164.  Distribution  of  Olfactory  nerve  ;  after  Erasmus  Wilson 666 

165.  Ciliary  Muscle;  after  Todd  and  Bowman 669 

166.  Vertical  Section  of  Retina;  after  H.  Muller 672 

167.  Elements  of  Human  Retina ;  after  H.  Muller. , 672 

168.  Distribution  of  Capillaries  in  Retina ;  after  Berres 673 

169.  Outer  surface  of  Retina,  showing  rods  of  Jacob's  Membrane;  after  Hannover...  673 

170.  Muscular  structure  of  Iris-;  after  Kolliker 675 

171.  Stereoscopic  figures;  original 679 

172.  Stereoscopic  projections  of  Pyramid ;  after  Wheatstone 680 

173.  Diagram  illustrating  Visual  Angle;  original 682 

174.  General  section  of  Ear;  after  Scarpa 691 

175.  Magnified  view  of  Lamina  Spiralis 692 

176.  Tympanic  surface  of  Lamina  Spiralis  of  a  Cat 692 

177.  Merobrana  Tympani 695 

178.  Ossicles  of  Ear 696 

179.  Diagram  of  inner  walls  of  Tympanum 697 

180.  Interior  of  Osseous  Labyrinth 698 

181.  Membranous  Labyrinth 698 

182.  Cochlea  of  new-born  Infant S99 


XXIV  LIST    OF    WOOD-ENGRAVINGS. 

FIG.  PAO1 

183.  View  of  left  Ear 703 

184.  Anterior  view  of  External  Ear,  Meatus  Auditorius,  &c 703 

185.  Muscles  of  the  Eyeball 710 

186.  Median  Section  of  Mouth,  Larynx,  &c. ;  after  Quain 717 

187.  Lateral  view  of  Larynx;  after  Willis 718 

188.  Sectional  view  of  do.  ;   after  Willis 718 

189.  Bird's-eye  view  of  Larynx  from  above  ;  after  Willis 718 

190.  Direction  of  Muscular  Forces  of  Larynx;  after  Willis 719 

191.  Artificial  Glottis;  after  Willis 723 

192.  View  of  the  Great  Sympathetic 733 

193.  Plan  of  the  Branches  of  the  Fifth  nerve 734 

194.  Roots  of  a  Dorsal  and  Spinal  nerve,  and  its  union  with  the  Sympathetic 735 

195.  Representation  of  nerves  of  Orbit 736 

196.  Otic  Ganglion 737 

197.  Olfactory  nerve  of  Meckel's  Ganglion 737 

198.  Human  Testis,  injected  with  Mercury ;  after  Lauth 748 

199.  Diagram  explanatory  of  do 749 

200.  Diagram  of  a  Graafian  Vesicle 753 

201.  Constituent  parts  of  Mammalian  Ovum  ;  after  Coste 754 

202.  Ovariurn  of  the  Rabbit  at  the  period  of  heat;  after  Pouchet 755 

203.  Cells  forming  substance  of  Corpus  Luteum  ;  after  Pouchet 759 

204.  Diagram  of  formation  of  Corpus  Luteum;  after  Pouchet 760 

205.  Corpora  Lutea  at  different  periods  760 

206.  Ovarian  Ovum  from  a  Bitch  in  heat 765 

207.  Section  of  lining  membrane  of  Uterus,  showing  glandular  follicles ;  after  Weber.  766 

208.  Portion  of  the  same,  more  highly  magnified;  after  Weber 766 

209.  Segments  of  Human  Decidua,  after  recent  impregnation 766 

210.  First  stage  of  formation  of  Decidua  reflexa;  after  Coste ,.   767 

211.  Second  stage  of  do.  do.  ;  after  Coste 767 

212.  Human  Ovum  of  Eighth  week,  showing  tufts  of  Chorion;  after  Ecker 768 

213.  Portion  of  ultimate  ramifications  of  Umbilical  Vessels ;  original 768 

214.  Portion  of  one  of  Foetal  Villi:  after  Ecker 769 

215.  Extremity  of  Placental  Villas ;  after  Good  sir 769 

216.  Section  of  Portion  of  Placenta;  after  Ecker 770 

217.  Diagram  of  structure  of  Placenta;  after  Dr.  J.  Reid 770 

218.  Cleaving  of  Yolk  after  fecundation 785 

219.  First  stages  of  Segmentation  of  Mammalian  Ovum;  after  Coste 786 

220.  Later  stages  of  do.  do.  ;  after  Coste 786 

221.  Plan  of  early  Uterine  Ovum  ;  after  Wagner 788 

222.  Diagram  of  Ovum  at  commencement  of  formation  of  Amnion;  after  Wagner....  788 

223.  Later  stage  of  formation  of  Amnion,  and  origin  of  Allantois ;  after  Wagner....  790 

224.  Completion  of  Amnion,  and  further  development  of  Allantois;  after  Wagner....  790 

225.  Diagram  of  Circulation  in  Human  Embryo,  as  seen  in  profile ;  after  Coste 792 

226.  Do.  do          ,  as  seen  in  front ;  after  Coste 792 

227.  Diagram  of  the  Foetal  Circulation;  after  Erasmus  Wilson 794 

228.  Embryo  of  Dog  at  twenty-five  days ;  after  Bisch off1 796 

229.  Origin  of  the  Liver  from  Intestinal  Wall,  in  embryo  Chick;  after  Miiller 797 

230.  First  appearance  of  the  Lungs  ;  after  Wagner 798 

231.  Urinary  and  Genital  Apparatus,  in  embryo  Chick ;  after  Miiller 799 

232.  Urinary  and  Genital  Organs  of  a  Human  Embryo 801 

233.  Typical  Vertebra,  and  thoracic  vertebra  of  Bird;  after  Owen 804 

234.  Parietal  Segment,  or  Vertebra 805 

235.  Origin  of  Encephalic  Centres,  in  Human  Embryo  of  Sixth  week ;  after  Wagner.  807 

236.  Encephalon  of  Human  Embryo  at  Twelfth  week;  after  Tiedemann 807 

237.  Diagram  of  Comparative  Viability  of  Male  and  Female;  after  Quetelet 811 

238.  Do.      do.  Comparative   Heights   and  Weights   of  Male   and  Female;    after 
Quetelet 812 

239.  Mammary  Gland  after  removal  of  Skin 814 

240.  Vertical  Section  of  Mammary  Gland 814 

241.  Distribution  of  Milk-ducts  in  Mammary  Gland;  after  Sir  A.  Cooper 815 

242.  Termination  of  Milk-duct  in  cluster  of  follicles;  after  Sir  A.  Cooper 816 

243.  Ultimate  follicles  of  Mammary  Gland,  with  secreting  cells;  after  Lebert 816 

244.  Microscopic  appearance  of  Human  Milk  ;  after  Funke 818 

245.  Profile  and  basal  views  of  prognathous  skull  of  Negro;  after  Prichard 828 

246.  Front  and  basal  views  of  pyramidal  skull  of  Esquimaux ;  after  Prichard 829 

247.  Oval  skull  of  European;  after  Prichard 829 

248.  Deciduous  and  Permanent  Teeth... 857 


HUMAN    PHYSIOLOGY. 


CHAPTER  I. 

OF  THE   DISTINCTIVE    CHARACTERISTICS   OP   MAN. 

1.  BY  Cuvier  and  nearly  all  modern  Zoologists,  the  various  races  of  Mankind 
are  included  under  one  genus,  Homo ;  and  this  genus  takes  rank,  in  the  classi- 
fication of  Mammalia,  as  a  distinct  order,  BIMANA,  of  which  it  is  the  sole 
representative.  Of  all  the  characters  which  distinguish  Man  from  the  inferior 
Mammalia,  the  possession  of  two  hands  is  doubtless  the  most  easily  recognized, 
and  at  the  same  time  the  most  intimately  related  to  the  general  organization  of 
the  body;  and  there  is  none,  therefore,  which  could  be  more  appropriately  se- 
lected as  the  basis  of  a  distinctive  designation  of  this  order.  At  first  sight  it 
might  be  considered  that  the  possession  of  only  two  hands,  whilst  Apes  and 
Monkeys  and  their  allies  are  designated  as  possessing  four,  is  a  character  of  in- 
feriority :  but  such  is  not  really  the  case ;  for  none  of  these  four  hands  are 
adapted  to  the  variety  of  actions  of  which  those  of  man  are  capable,  and  they 
are  all  in  some  degree  required  for  a  support ;  so  that  whilst  in  the  higher  forms 
of  the  Quadrumanous  order,  the  extremities  present  a  certain  approximation  in 
structure  to  those  of  Man,  in  the  lower  they  gradually  assimilate  to  the  ordinary 
quadrupedal  type.  "That,"  says  Cuvier,  "which  constitutes  the  hand,  pro- 

Fio.  1. 


Hand  of  Man,  compared  with  anterior  extremity  of  Orang. 

perly  so  called,  is  the  faculty  of  opposing  the  thumb  to  the  other  fingers,  so  as 

to  seize  upon  the  most  minute  objects;  a  faculty  which  is  carried  to  its  highest; 

degree  of  perfection  in  Man,  in  whom  the  whole  anterior  extremity  is  free,  and 

3  (33) 


34  HUMAN    PHYSIOLOGY. 

can  be  employed  in  prehension."  The  peculiar  prehensile  power  possessed  by 
Man,  is  chiefly  dependent  upon  the  size  and  power  of  the  thumb ;  which  is 
more  developed  in  him,  than  it  is  in  the  highest  Apes  (Fig.  1).  The  thumb  of 
the  Human  hand  can  be  brought  in  exact  opposition  to  the  extremities  of  all  the 
fingers,  whether  singly  or  in  combination;  whilst  in  those  Quadrumana  which 
most  nearly  approach  man,  the  thumb  is  so  short,  and  the  fingers  so  much  elon- 
gated, that  their  tips  can  scarcely  be  brought  into  opposition ;  and  the  thumb 
and  fingers  are  so  weak,  that  they  can  never  be  opposed  to  each  other  with  any 
degree  of  force.  Hence,  although  well  suited  to  cling  round  bodies  of  a  certain 
size,  such  as  the  small  branches  of  trees,  &c.,  the  extremities  of  the  Quadru- 
mana can  neither  seize  very  minute  objects  with  such  precision,  nor  support  large 
ones  with  such  firmness,  as  are  essential  to  the  dexterous  performance  of  a  vari- 
ety of  operations,  for  which  the  hand  of  Man  is  admirably  adapted.  There  is 
much  truth,  then,  in  Sir  C.  Bell's  remark,  that  "we  ought  to  define  the  hand 
as  belonging  exclusively  to  Man."  There  is  in  him,  what  we  observe  in  none 
of  the  Mammalia  which  approach  him  in  other  respects,  a  complete  distinction 
in  the  functional  character  of  the  anterior  and  posterior  extremities ;  the  former 
being  adapted  for  prehension  alone,  and  the  latter  for  support  and  progression 
alone  :  and  thus  each  function  is  performed  in  a  much  higher  degree  of  perfec- 
tion, than  it  can  be  when  two  such  opposite  purposes  have  to  be  united.  For 
not  only  is  the  hand  of  Man  a  much  more  perfect  prehensile  instrument  than 
that  of  the  Orang  or  Chimpanzee,  but  his  foot  is  a  much  more  perfect  organ  of 
support  and  progression  than  theirs,  being  adapted  to  maintain  his  body  in  an 
erect  position,  alike  during  rest  and  whilst  in  motion  (§  5) ;  an  attitude  which 
even  the  most  anthropoid  apes  can  only  sustain  for  a  short  time,  and  with  an 
obvious  effort.  The  arm  of  the  higher  Apes  has  as  wide  a  range  of  motion  as 
that  of  Man,  so  far  as  its  articulation  is  concerned;  but  it  is  only  when  the 
animal  is  in  the  erect  attitude,  that  the  limb  can  have  free  play.  Thus  the 
structure  of  the  whole  frame  must  be  conformable  to  that  of  the  hand,  in  the 
way  that  we  find  it  to  be  in  Man,  in  order  that  this  organ  may  be  advantageously 
applied  to  the  purposes  which  it  is  adapted  to  perform.  But  it  cannot  be  said 
with  truth  (as  some  have  maintained)  that  Man  owes  his  superiority  to  his  hand 
alone ;  for  without  the  mind  by  which  it  is  directed,  and  the  senses  by  which 
its  operations  are  guided,  it  would  be  a  comparatively  valueless  instrument. 
Man's  elevated  position  is  due  to  the  superiority  of  his  mind  and  of  its  material 
instruments  conjointly;  for  if  destitute  of  either,  the  human  race  must  be 
speedily  extinguished  altogether,  or  reduced  to  a  very  subordinate  grade  of  ex- 
istence. 

2.  The  next  series  of  characters  to  be  considered,  are  those  by  which  Man 
is  adapted  to  the  erect  attitude.  —  On  examining  his  cranium,  we  remark  that 
the  occipital  condyles  are  so  placed,  that  a  perpendicular  dropped  from  the 
centre  of  gravity  of  the  head  would  nearly  fall  between  them,  so  as  to  be  within 
the  base  on  which  it  rests  upon  the  spinal  column.  The  foramen  magnum  is 
not  placed  in  the  centre  of  the  base  of  the  skull,  but  just  behind  it ;  so  that 
the  greater  specific  gravity  of  the  posterior  part  of  the  head,  which  is  entirely 
filled  with  solid  matter,  is  compensated  by  the  greater  length  of  the  anterior  part, 
which  contains  many  cavities.  There  is,  indeed,  a  little  over-compensation, 
which  gives  a  slight  preponderance  to  the  front  of  the  head,  so  that  it  drops 
forwards  and  downwards  when  all  the  muscles  are  relaxed;  but  the  muscles 
which  are  attached  to  the  back  of  the  head  are  far  larger  and  more  numerous 
than  those  in  front  of  the  condyles,  so  that  they  are  evidently  intended  to  coun- 
teract this  disposition;  and  we. find,  accordingly,  that  we  can  keep  up  the  head 
for  the  whole  day,  with  so  slight  and  involuntary  an  effort,  that  no  fatigue  is 
produced  by  it.  Moreover,  the  plane  of  the  foramen  magnum,  and  the  surfaces 
of  the  condyles,  have  a  nearly  horizontal  direction  when  the  head  is  upright ; 
and  thus  the  weight  of  the  skull  is  laid  vertically  upon  the  top  of  the  vertebral 


DISTINCTIVE  CHAKACTERISTICS  OF  MAN.        85 

column.  —  If  these  arrangements  be  compared  with  those  which  prevail  in  other 
Mammalia,  it  will  be  found  that  the  foramen  and  condyles  are  placed  in  the 
latter  much  nearer  the  back  of  the  head,  and  that  their  plane  is  more  oblique. 
Thus,  whilst  the  foramen  magnum  is  situated,  in  Man,  just  behind  the  centre  of 
the  base  of  the  skull,  it  is  found,  in  the  Chimpanzee  and  Orang  Outan,  to  oc- 
cupy the  middle  of  the  posterior  third  (Fig.  2) ;  and,  as  we  descend  through 

Fro.  2. 


View  of  the  base  of  the  Skull  of  J/«n,  compared  with  that  of  the  Orang  Outan. 

the  scale  of  Mammalia,  we  observe  that  it  gradually  approaches  the  back  of  the 
skull,  and  at  last  comes  nearly  into  the  line  of  its  longest  diameter,  as  we  see 
in  the  Horse.  Again,  in  all  Mammalia,  except  Man,  the  plane  of  the  condyles 
is  oblique,  so  that,  even  if  the  head  were  equally  balanced  upon  them,  the  force 
of  gravity  would  tend  to  carry  it  forwards  and  downwards:  in  Man,  the  angle 
which  they  make  with  the  horizon  is  very  small  •  in  the  Orang  Outan,  it  is  as 
much  as  37° ;  and  in  the  Horse,  their  plane  is  vertical,  making  the  angle  90°. 
If,  therefore,  the  natural  posture  of  Man  were  horizontal,  the  plane  of  his  con- 
dyles would  be  brought,  like  that  of  the  Horse,  into  the  vertical  position ;  and 
the  head,  instead  of  being  nearly  balanced  on  the  summit  of  the  vertebral 
column,  would  hang  at  the  end  of  the  neck,  so  that  its  whole  weight  would 
have  to  be  supported  by  some  external  and  constantly-acting  power.  But  for 
this,  there  is  neither  in  the  skeleton,  the  ligamentous  apparatus,  nor  the  mus- 
cular system  of  Man,  any  adequate  provision;  so  that  in  any  other  than  the 
vertical  position,  his  head,  which  is  relatively  heavier  than  that  of  most  Mam- 
malia, would  be  supported  with  more  difficulty  and  effort  than  it  is  in  any  other 
animal.  [The  attention  of  naturalists  has  been  drawn,  by  Dr.  J.  Neill,1  to  a 
peculiar  formation  of  the  condyloid  processes  of  the  occiput  which  has  not  been 
ordinarily  described;  and,  although  the  number  of  observations  has  not  been 
sufficiently  great  to  justify  a  determinate  conclusion,  enough  has  been  done  to 
prove  its  existence  in  a  great  number  of  cases.  The  condyloid  processes  have 
been  described  as  oblong  and  converging  eminences  on  each  side  of  the  anterior 
semi- circumference  of  the  foramen  magnum  occipitis,  leaving  smooth  and  convex 
surfaces  for  articulating  with  the  atlas,  the  internal  margins  of  which  are  deeper 
than  the  external,  with  a  roughness  on  the  inside  and  a  depression  on  the  outside 
for  the  attachment  of  ligaments. 

According  to  the  observation  of  Dr.  Neill,  this  description  will  be  found  defi- 
cient, with  regard  to  a  striking  peculiarity.     In  some  instances  the  articulating 

1  Amer.  Jour.  Med.  Sciences,  Jan.  1850. 


36 


HUMAN    PHYSIOLOGY. 


surface  of  the  condyloid  process  will  be  found  to  present  the  outline  of  the  figure 
8  ;  in  others,  to  be  divided  by  a  transverse  ridye  or  groove  into  two  distinct  arti- 
cular surfaces,  which  are  often  in  different  planes.  (Figs.  3  and  4.) 


FIG.  3. 


FIG.  4 


Upon  examination  of  a  large  number  of  crania,  in  probably  the  largest  collec- 
tion in  the  world,  that  of  the  late  Dr.  Morton,  it  was  found  to  occur  most  fre- 
quently in  the  African  variety,  thirty  out  of  eighty-one  presenting  it;  whilst  in 
the  Caucasian  varieties  only  four  out  of  one  hundred  and  twenty-five  showed  it. 
It  appears  from  this  enumeration,  that  the  feature  occurs  more  frequently  in  the 
African  race  than  in  either  the  Caucasian,  Mongolian,  or  aboriginal  American, 
specimens  from  each  of  which  were  carefully  examined ;  and  the  results  were  more 
striking  when  the  old  heads  were  excluded,  in  which  friction  had  rendered  the 
condyloid  processes  flat  and  smooth. 

Dr.  Neill  proposes  this  observation  in  illustration  of  a  law  developed  by  Pro- 
fessor Agassiz,  "  that,  in  the  different  formations  through  which  animals  pass, 
from  the  first  formation  in  the  embryo  up  to  the  full-grown  condition,  may  be 
found  a  natural  scale  by  which  to  measure  and  estimate  the  position  to  ascribe  to 
sny  animal." 

In  the  foetal  head  the  occiput  consists  of  four  pieces.  The  first  piece,  or  basi- 
occipital  bone  of  Owen,  is  separated  from  the  two  lateral  portions  by  a  fissure 
running  through  the  condyles;  this  piece  remains  permanently  separated  in  the 
cold-blooded  vertebrata,  and  in  the  African  head,  also,  the  basi-occipital  bone  is 
frequently  retained.  This  apparently  undeveloped  state  of  the  occipital  bone  is 
regarded  by  the  observer  as  expressive  of  the  position  of  the  African  in  the  human 
family.  —  ED.] 

3.  The  position  of  the  face  immediately  beneath  the  brain,  so  that  its  front  is 
nearly  in  the  same  plane  as  the  forehead,  is  peculiarly  characteristic  of  Man ;  for 
the  crania  of  the  Chimpanzee  and  Orang,  which  approach  nearest  to  that  of  Man, 
are  rather  posterior  to,  than  above,  the  face  (Figs.  5,  6).  The  projection  of  the 
muzzle,  taken  in  connection  with  the  obliquity  of  the  condyles,  is  another  evi- 
dence of  want  of  perfect  adaptation  to  the  erect  posture ;  whilst  the  absence  of 
prominence  in  the  face  of  Man  shows  that  none  but  the  erect  position  can  be 
natural  to  him.  For  supposing  that,  with  a  head  formed  and  situated  as  at  pre- 
sent, he  were  to  move  on  all-fours,  his  face  would  be  brought  into  a  plane  parallel 
with  the  ground ;  so  that  as  painful  an  effort  would  be  required  to  examine  with 
the  eyes  an  object  placed  in  front  of  the  body,  as  is  now  necessary  to  keep  the 
eyes  fixed  on  the  zenith ;  the  nose  would  then  be  incapacitated  for  receiving  any 
other  odorous  emanations  than  those  proceeding  from  the  earth  or  from  the  body 
itself;  and  the  mouth  could  not  touch  the  ground,  without  bringing  the  forehead 
and  chin  also  into  contact  with  it.  The  oblique  position  of  the  condyles  in  the 


DISTINCTIVE    CHARACTERISTICS    OF    MAN 


37 


Quadrumana  enables  them,  without  much  difficulty,  to  adapt  the  inclination  of 
their  heads  either  to  the  horizontal  or  to  the  erect  posture ;  but  the  natural  posi- 
tion, in  the  highest  among  them,  is  unquestionably  one  in  which  the  spinal 
column  is  inclined,  the  body  being  partially  thrown  forwards,  so  as  to  rest  upon 
the  anterior  extremities;  and  in  this  position  the  face  is  directed  forward  without 
any  effort,  owing  to  the  mode  in  which  the  head  is  obliquely  articulated  with  the 
spine  (Fig.  5). 

PIG.  5. 


Skeleton  of  Gorilla. 


4.  The  vertebral  column  in  Man,  although  not  absolutely  straight,  has  its 
curves  so  arranged,  that,  when  the  body  is  in  an  erect  posture,  a  vertical  Hue  from 
its  summit  would  fall  exactly  on  the  centre  of  its  base.  It  increases  considerably 
in  size  in  the  lumbar  region,  so  as  to  be  altogether  somewhat  pyramidal  in  form. 
The  lumbar  portion,  in  the  Chimpanzee  and  Orang,  is  not  of  the  same  propor- 
tional strength ;  and  contains  but  four  vertebrae,  instead  of  five.  The  processes 
for  the  attachment  of  the  dorso-spinal  muscles  to  this  part,  are  peculiarly  large 
and  strong  in  Man ;  and  this  arrangement  is  obviously  adapted  to  overcome  the 


58  H  U  M  A  X     P II  Y  S  I  0  L  0  G  T. 

tendency,  which  the  weight  of  the  viscera  in  front  of  the  column  would  have,  to 
draw  it  forwards  and  downwards.  On  the  other  hand,  the  spinous  processes  of 
the  cervical  and  dorsal  vertebrae,  which  are  in  other  Mammalia  large  and  strong 
for  the  attachment  of  the  ligaments  and  muscles  that  support  the  head,  have  com- 
paratively little  prominence  in  Man,  his  head  being  nearly  balanced  on  the  top 

[FiG.  6. 


Comparative  view  of  the  Skeleton  of  Man  and  that  of  the  Orang  Outan.] 

of  the  column.  —  The  base  of  the  Human  vertebral  column  is  placed  on  a  sacrum 
of  greater  proportional  breadth  than  that  of  any  other  animal  \  this  sacrum  is 
fixed  between  two  widely  expanded  ilia ;  and  the  whole  pelots  is  thus  peculiarly 
broad.  In  this  manner,  the  femoral  articulations  are  thrown  very  far  apart,  so  as 
to  «ive  a  wide  basis  of  support;  and  by  the  oblique  direction  of  the  pelvis,  the 


DISTINCTIVE    CHARACTERISTICS     OF    MAN.  89 

weight  of  the  body  is  transmitted  almost  vertically  from  the  top  of  the  sacrum  to 
the  upper  part  of  the  thigh-bones.  The  pelvis  of  the  anthropoid  Apes  is  very 
differently  constructed ;  as  will  be  seen  in  Fig.  6,  in  which  the  skeleton  of  ihe 
Orang  is  placed  in  proximity  with  that  of  Man.  It  is  much  larger  and  narrower; 
its  alse  extend  upwards  rather  than  outwards,  so  that  the  space  between  the  lowest 
ribs  and  the  crest  of  the  iliac  bones  is  much  less  than  in  Man ;  their  surfaces  are 
nearly  parallel  to  that  of  the  sacrum,  which  is  itself  longer  and  narrower;  and  the 
axis  of  the  pelvis  is  nearly  parallel  with  that  of  the  vertebral  column.  The  posi- 
tion of  the  Human  femur,  in  which  its  head  is  most  securely  retained  in  its  deep 
acetabulum,  is  that  which  it  has  when  supporting  the  body  in  the  erect  attitude ; 
in  the  Chimpanzee  and  Orang,  its  analogous  position  is  at  an  oblique  angle  to  the 
long  axis  of  the  pelvis,  so  that  the  body  leans  forwards  in  front  of  it;  in  many 
Mammalia,  as  in  the  Elephant,  it  forms  nearly  a  right  angle  with  the  vertebral 
column;  and  in  several  others,  as  the  Horse,  Ox,  &c.,  the  angle  which  it  makes 
with  the  axis  of  the  pelvis  and  vertebral  column  is  acute.  In  this  respect,  then, 
the  skeleton  of  Man  presents  an  adaptation  to  the  erect  posture,  which  is  exhibited 
by  that  of  no  other  Mammal. 

5.  The  lower  extremities  of  Man  are  remarkable  for  their  length  ;  which  is  pro- 
portionably  greater  than  that  which  we  find  in  any  other  Mammalia,  except  the 
Kangaroo  tribe.  The  chief  difference  in  their  proportional  length,  between  Man 
and  the  semi-erect  Apes,  is  seen  in  the  thigh ;  and  it  is  from  the  relative  length 
of  this  part  in  him,  as  well  as  from  the  comparative  shortness  of  his  anterior 
extremities,  that  his  hands  only  reach  the  middle  of  his  thighs,  whilst  in  the 
Chimpanzee  they  hang  on  a  level  with  the  knees  (Fig.  5),  and  in  the  Orang  they 
descend  to  the  ankles  (Fig.  6).  The  Human  femur  is  distinguished  by  its  form 
and  position,  as  well  as  by  its  length.  The  obliquity  and  length  of  its  neck  still 
further  increase  the  breadth  of  the  hips;  whilst  they  cause  the  lower  extremities 
of  the  femora  to  be  somewhat  obliquely  directed  towards  each  other,  so  that  the 
knees  are  brought  more  into  the  line  of  the  axis  of  the  body.  This  arrangement 
is  obviously  of  great  use  in  facilitating  the  purely  biped  progression  of  Man,  in 
which  the  entire  weight  of  the  body  has  to  be  alternately  supported  on  each  limb; 
for  if  the  knees  had  been  kept  further  apart,  the  whole  body  must  have  been 
swung  from  side  to  side  at  each  step,  so  as  to  bring  the  centre  of  gravity  over  the 
top  of  each  tibia;  as  is  seen  to  a  certain  extent  in  the  female  sex,  whose  walk, 
owing  to  the  greater  breadth  of  the  pelvis  and  the  separation  between  the  knees, 
is  less  steady  than  that  of  the  male.  There  is  a  very  marked  contrast  between 
the  knee-joint  of  Man,  and  that  of  even  the  highest  Apes.  In  the  former,  the 
opposed  extremities  of  the  femur  and  the  tibia  are  expanded,  so  as  to  present  a 
very  broad  articulating  surface ;  and  the  internal  condyle  of  the  femur  being  the 
longer  of  the  two,  they  are  in  the  same  horizontal  plane  in  the  usual  oblique  posi- 
tion of  that  bone;  so  that  by  this  arrangement,  the  whole  weight  of  the  body,  in 
its  erect  posture,  falls  vertically  on  the  top  of  the  tibia,  when  the  joint  is  in  the 
firmest  position  in  which  it  can  be  placed.  The  knee-joint  of  the  Orang,  on  the 
other  hand,  is  comparatively  deficient  in  extent  of  articulating  surface;  and  its 
whole  conformation  indicates  that  it  is  not  intended  to  serve  as  more  than  a  par- 
tial support.  —  The  human  foot  is,  in  proportion  to  the  size  of  the  whole  body, 
larger,  broader,  and  stronger,  than  that  of  any  other  Mammal  save  the  Kangaroo. 
Its  plane  is  directed  at  right  angles  to  that  of  the  leg ;  and  its  sole  is  concave,  so 
that  the  weight  of  the  body  falls  on  the  summit  of  an  arch,  of  which  the  os  calcis 
and  the  metatarsal  bones  form  the  two  points  of  support.  This  arched  form  of 
the  foot,  and  the  natural  contact  of  the  os  calcis  with  the  ground,  are  peculiar  to 
Man  alone.  All  the  Apes  have  the  os  calcis  small,  straight,  and  more  or  less 
raised  from  the  ground ;  which  they  touch,  when  standing  erect,  with  the  outer 
side  only  of  the  foot :  whilst  in  animals  more  remote  from  Man,  the  os  calcis  is 
brought  still  more  into  the  line  of  the  tibia;  and  the  foot  being  more  elongated 
-'ind  narrowed,  only  the  extremities  of  the  toes  come  in  contact  with  the  ground. 


40  HUMAN     PHYSIOLOGY. 

Hence  Man  is  the  only  species  of  Mammal  which  can  stand  upon  one  leg.  All 
the  points  in  which  the  feet  of  the  anthropoid  Apes  differ  from  his,  are  such  as 
assimilate  them  to  the  manual  type  of  conformation,  and  enable  them  to  serve  as 
more  efficient  prehensile  organs ;  whilst  they  diminish  their  capacity  to  sustain 
the  weight  of  the  body,  when  it  simply  rests  upon  them  (Fig.  7). 

FIG.  r. 


Foot  of  Man,  compared  with  posterior  extremity  of  Orang. 

6.  There  is  a  considerable  difference  in  the  form  of  the  trunk,  between  Man 
and  most  other  Mammalia ;  for  his  thorax  is  expanded  laterally,  and  flattened  in 
front,  so  as  to  prevent  the  centre  of  gravity  from  being  carried  too  far  forwards ; 
and  his  sternum  is  short  and  broad.     Between  the  bony  walls  of  the  thorax  and 
the  margin  of  the  pelvis,  a  considerable  space  intervenes,  which  is  occupied  solely 
by  muscles  and  tegumentary  membranes ;  and  these  would  be  quite  insufficient 
to  sustain  the  weight  of  the  viscera,  if  the  habitual  position  of  the  trunk  had  been 
horizontal. — In  these  particulars,  however,  the  most  anthropoid  Apes  agree  more 
or  less  completely  with  Man. 

7.  Returning  now  to  the  skull  for  a  more  minute  examination,  we  observe  that 
the  cranium  of  Man  is  distinguished  from  that  of  the  anthropoid  Apes,  not  merely 
by  its  great  capacity,  but  also  by  its  smoothness  j  its  surface  being  almost  entirely 
deficient  in  those  ridges  for  the  attachment  of  muscles,  which  are  remarkably 
strong  in  both  the  Chimpanzee  and  the  Orang,  and  which  impart  to  its  configu- 
ration somewhat  of  a  carnivorous  character.     This  aspect  is  strengthened  by  the 
great  depth  of  the  temporal  fossa,  and  by  the  extent  and  strength  of  the  zygo- 
matic  arch;  features  that  are  most  remarkably  developed  in  the   Troglodyte* 
gorilla,  a  newly-discovered  species  of  Chimpanzee,  which  is  regarded  by  Prof. 
Owen  as  presenting  on  the  whole   the   nearest  approach   to  the  human  type 
(Fig.  5).     Moreover,  the  jaws  in  even  the  most  degraded  races  of  Man  project 
far  less  from  the  general  plane  of  the  face,  than  they  do  in  the  Apes ;  and  his 
teeth  are  arranged  in  a  continuous  series,  without  any  hiatus  or  any  considerable 
difference  in  length  :  whilst  all  the  Apes,  in  their  adult  state  at  least,  are  fur- 
nished with  canine  teeth  of  extraordinary  length,  between  the  sockets  of  which 
and  those  of  the  adjoining  teeth  (anteriorly  in  the  upper  jaw,  and  posteriorly  in 
the  lower),  there  is  a  vacant  space  or  diastema.     Even  in  the  most  prognathous 
Human  skulls,  moreover,  the  incisors  meet  each  other  much  more  nearly  in  the 
same  axis,  than  they  do  in  the  anthropoid  Apes,  in  which  they  form  an  angle 
with  each  other  that  is  not  nearly  so  divergent:     The  fusion  of  the  intermaxillary 
or  premaxillary  bones  with  the  superior  maxillary,  at  an  early  period  of  festal  life, 
is  a  remarkable  character  of  the  Human  cranium,  as  distinguishing  it  from  that 


DISTINCTIVE    CHARACTERISTICS     OF    MAN. 


41 


of  the  Apes,  in  which  the  intermaxillary  bones  remain  separate  to  a  much  later 
period ;  sometimes  differing  also,  in  a  very  marked  degree,  in  size  and  shape. 
Thus  in  the  Troglodytes  gorilla,  these  bones  are  not  only  remarkable  for  their 
prominence,  but  also  for  their  upward  extension  round  the  nostrils,  so  that  they 
completely  exclude  the  maxillary  bones  from  their  borders,  and  form  the  basis  of 
support  for  the  nasal  bones  j  and  although  they  coalesce  with  the  maxillaries  at 
and  near  the  alveolar  portion,  they  remain  separate  elsewhere.  The  lower  jaw  of 
Man  is  remarkable  for  that  prominence  at  its  symphysis,  which  forms  the  chin ; 
and  although  this,  also,  is  least  developed  in  the  most  prognathous  human  crania, 
yet  it  is  never  so  deficient  as  it  is  in  the  lower  jaw  of  the  Chimpanzee  and  Orang. 
—  It  is  curious  to  observe  that  the  skulls  of  the  young  of  Man  and  of  the  anthro- 
poid Apes  resemble  one  another  much  more  than  do  those  of  the  adults;  each 
tending  to  diverge,  in  its  advance  towards  full  development,  from  a  type  which 
seemed  almost  similar  in  both  (Figs.  8,  9,  10).  It  is  at  the  time  of  the  second 


FIG.  8. 


FIG.  9. 


Vertical  section  of  Skull  of  Adult  Orang.  Vertical  section  of  Skull  of  Young  Orang. 

FIG.  10. 


Vertical  section  of  Skull  of  Papuan  Negrito. 

dentition,  that  the  muzzle  of  the  anthropoid  Apes  acquires  its  peculiar  elongation, 
and  consequent  projection  in  front  of  the  forehead  (Figs  2,  8);  and  the  whole 
cast  of  the  features  is  altered  at  the  same  time,  so  that  it  approaches  much  more 
to  that  of  the  lower  Quad  rum  an  a,  than  would  be  supposed  from  observation  of 


42  IT  U  M  A  N     P  H  Y  S  I  0  L  0  G  Y. 

the  young  animal  only.1  In  the  Human  subject,  on  the  other  hand,  we  see  that 
in  the  advance  from  childhood  to  adult  age,  there  is  a  progressive  enlargement 
of  the  face,  in  proportion  to  the  capacity  of  the  cranial  cavity.2 

8.  The  great  size  of  the  cranial  portion  of  the  skull  in  Man,  as  compared  with 
the  facial,  produces  a  marked  difference  between  his  "  facial  angle,"  and  that  of 
even  the  highest  Quadrumana.     According  to  Camper,  who  first  applied   this 
method  of  measurement,  the  "  facial  angle"  of  the  average  of  European  skulls  is 
80°,  whilst  in  the  ideal  heads  of  the  Grecian  gods  it  is  increased  to  90° ;  on  the 
other  hand,  in  the  skull  of  a  Kalmuck  he  found  it  to  be  75°;  and  in  that  of  a 
Negro  only  70° ;  and  applying  the  same  system  of  measurement  to  the  skulls  of 
Apes,  he  found  them  to  range  from  64°  to  60°-     But  these  last  measurements 
were  all  taken  from  young  skulls,  in  which  the  forward  extension  of  the  jaws, 
which  takes  place  on  the  second  dentition,  had  not  yet  occurred.     In  the  adult 
Chimpanzee,  as  Prof.  Owen  has  shown,  the  "facial  angle"  (Figs.  8,  9,  10,  AOP), 
is  no  more  than  35°,  and  in  the  adult  Orang  only  80° ;  so  that  instead  of  the 
Negro  being  nearer  to  the  Ape  than  to  the  European,  as  Camper's  estimate  would 
make  him,  the  interval  between  the  most  degraded  Human  races  and  the  most 
elevated  Quadrumana  is  vastly  greater  than  between  the  highest  and  the  lowest 
forms  of  Humanity.     It  must  be  borne  in  mind  that  the  "facial  angle"  is  so 
much  affected  by  the  degree  of  prominence  of  the  jaws,  that  it  can  never  afford 
any  certain  information  concerning  the  elevation  of  the  forehead  and  the  capacity 
of  the  cranium ;  all  that  it  can  in  any  degree  serve  to  indicate,  being  the  relative 
proportion  between  the  facial  and  the  cranial  parts  of  the  skull.     This  proportion 
is  far  more  correctly  determined,  as  Prof.  Owen  has  shown,3  by  vertical  sections 
of  the  skulls  to  be  compared,  through  their  median  planes  (Figs.  8,  9,  10). 

9.  The  most  characteristic  peculiarity  of  the  Human  Myology,  is  the  great 
development  of  those  muscles  of  the  trunk  and  limbs  which  contribute  to  the 
maintenance  of  the  erect  posture.     Thus,  the  gastrocnemii,  and  the  other  mus- 
cles which  tend  to  keep  the  leg  erect  upon  the  foot,  form  a  much  more  prominent 
'calf  than  is  seen  either  in  the  most  anthropoid  Apes,  or  in  any  other  animal. 
So,  again,  the  extensors  of  the  leg  upon  the  thigh  are  much  more  powerful  than 
the  flexors;  a  character  which  is  peculiar  to  Man.     The  glutaei,  by  which  the 
pelvis  is  kept  erect  upon  the  thigh,  are  of  far  greater  size  than  is  elsewhere  seen. 
The  superior  power  of  the  muscles  tending  to  draw  the  head  and  spine  backwards 
has  been  already  referred  to.     Among  the  differences  in  the  attachment  of  indi- 
vidual muscles,  it  may  be  noticed  that  the  '  flexor  longus  pollicis  pedis'  proceeds 
in  Man  to  the  great  toe  alone,  on  which  the  weight  of  the  body  is  often  sup- 
ported; whilst  it  is  attached  in  the  Chimpanzee  and  Orang  to  the  three  middle 
toes  also.    The  ( latissimus  dorsi'  is  destitute  in  Man  of  that  prolongation  attached 
to  the  olecranon,  which  is  found  in  the  lower  Mammalia,  and  which  exists  even 
in  the  Chimpanzee,  probably  giving  assistance  in  its  climbing  operations.     The 
larger  size  of  the  muscles  o'f  the  thumb  is,  as  might  be  expected,  a  characteristic 
of  the  hand  of  Man ;  although  the  number  of  muscles  by  which  that  digit  is 
moved,  is  the  same  in  the  Chimpanzee  as  in  the  Human  subject.     The  existence 
of  the  l  extensor  digiti  indicis,'  however,  as  a  distinct  muscle,  is  peculiar  to  Man. 

10.  The  Visceral  apparatus  of  Man  presents  very  few  characteristic  peculiar- 
ities, by  which  it  can  be  distinguished  from   that  of  the  higher  Quadrumana ; 
among  the  most  remarkable  is  the  absence  of  the  laryngeal  pouches,  which  exist 
even  in  the  Chimpanzee  and  Orang  Outan,  as  dilatations  of  the  laryngeal  ventri- 

1  None  but  young  specimens  of  the  Chimpanzee  and  Orang  Outan  have  ever  been  brought 
Viive  to  this  country ;  and  they  have  never  long  survived  the  period  of  their  second  den- 
tition. 

2  See  Prof.  Owen's  Papers  on  the  Anatomy  of  the  Orang  and  Chimpanzee,  in  the  "Zo- 
ological Transactions,"  vols.  i.  and  iii.  ;  and  Prof.  Vrolik  in  the  Art.  Quadrumana  in  the 
''  Cyclopaedia  of  Anatomy  and  Physiology,"  vol.  iv. 

''  Zoological  Transactions,"  vol.  iv.,  p.  77,  el  seq. 


\ 
DISTINCTIVE     CHARACTERISTICS     OF    MAN.  43 

ties.  —  Of  the  anatomy  of  the  last-named  animals  in  their  adult  condition,  how- 
ever, we  know  as  yet  too  little  to  enable  its  conformity  to  that  of  man  to  be  con- 
fidently pronounced  upon. 

11.  The  Brain  of  Man  does  not  differ  so  much  in  conformation  from  that  of 
the  Chimpanzee  and  Orang,  as  the  superiority  of  his  mental  endowments  might 
have  led  us  to  anticipate.     The  following  are  the  principal  differences  which  it 
seems  to  present : — 1.  The  mass  of  the  entire  brain  is  considerably  larger  in  pro- 
portion to  that  of  the  body,  and  in  proportion  also  to  the  diameter  of  the  spinal 
cord  and  of  the  nerves  which  are  connected  with  it. — 2.  In  the  external  configu- 
ration of  the  Cerebrum,  we  notice  that  its  anterior  lobes  project  further  beyond 
the  Rhinencephalon,  or  Olfacfive  Ganglion ,  than  they  do  in  the  highest  Quadru- 
niana ;  a  difference  which  is  well  marked  in  the  sectional  contour  of  the  brain- 
case,  the  rhinencephalic  fossa  of  the  Orang  (Fig.  8,  rJi)  being  at  its  most  anterior 
part,  whilst  even  in  the  least  elevated  forms  of  the  Human  skull,  this  fossa,  (of 
which  the  cribriform  plate  of  the  ethmoid  bone  constitutes  the  floor)  has  no  incon- 
siderable part  of  the  cranial  cavity  in  front  of  it  (Fig.  10,  rh). — 3.  The  posterior 
lobes  also  are  more  developed,  so  as  to  project  further  beyond  the  Cerebellum 
than  they  do  iu  any  of  the  Quadrumana ;  the  convolutions  are  more  numerous, 
and  the  sulci  are  deeper.  —  4.   On  examining  the  internal  structure,  it  is  found 
that  the  peripheral  layer  of  grey  matter  is  thicker,  the  corpus  callosum  extends 
further  backwards,  and  the  posterior  cornua  of  the  lateral  ventricles  are  relatively 
longer  and  larger  than  they  are  in  any  Quadrumana.  —  5.  The  Cerebellum,  also, 
is  proportionally  larger. 

12.  The  small  size  of  the  face  of  Man,  compared  with  that  of  the  cranium,  is 
an  indication  that  in  him  the  senses  are  subordinate  to  the  intelligence.     Accord- 
ingly we  find  that,  while  he  is  surpassed  by  many  of  the  lower  animals  in  acute- 
ness  of  sensibility  to  light,  sound,  &c.,  he  stands  pre-eminent  in  the  power  of 
comparing  and  judging  of  his  sensations,  and  of  drawing  conclusions  from  them 
as  to  their  objective  sources.     Moreover,  although  none  of  his  senses  are  very 
acute  in  his  natural  state,  they  are  all  moderately  so ;  and  they  are  capable  of 
being  wonderfully  improved  by  practice,  when  circumstances  strongly  call  for 
their  exercise.     This  seems  especially  the  case  with  the  tactile  sense,  of  which 
Man  can  make  greater  use  than  any  other  animal,  in  consequence  of  the  entire 
freedom  of  his  anterior  extremities ;  although  there  are  many  which  surpass  him 
in  their  power  of  appreciating  certain  classes  of  tactile  impressions. — So,  again, 
Man's  nervo-muscular  power  is  inferior  to  that  of  most  other  animals  of  his  size; 
the  full-grown  Orang,  for  example,  surpasses  him  both  in  strength  and  agility; 
and  the  larger  Chimpanzee,  according  to  the  statements  of  the  Negroes  who  have 
encountered  it,  is  far  more  than  a  match  for  any  single  man,  and  is  almost  certain 
to  destroy  any  human  opponent  once  within  his  grasp.  —  The  absence  of  any  na- 
tural weapons  of  offence,  and  of  direct  means  of  defence,  are  remarkable  charac- 
teristics of  Man,  and  distinguish  him  not  only  from  the  lower  Mammalia,  but 
also  from  the  most  anthropoid  Apes;  in  which  it  is  obvious  (both  from  their 
habits  and  general  organization)  that  the  enormous  canines  have  no  relation  to  a 
carnivorous  regimen,  but  are  instruments  of  warfare.     On  those  animals  to  which 
Nature  has  denied  weapons  of  attack,  she  has  bestowed  the  means  either  of 
passive  defence,  of  concealment,  or  of  flight;  in  each  of  which  Man  is  deficient. 
Yet,  by  his  superior  reason,  he  has  been  enabled  not  only  to  resist  the  attacks 
of  other  animals,  but  even  to  bring  them  into  subjection  to  himself.     His  intel- 
lect can  scarcely  suggest  the  mechanism  which  his  hands  cannot  frame;  and  he 
has  devised  and  constructed  arms  more  powerful  than  those  which  any  creature 
wields,  and  defences  so  secure  as  to  defy  the  assaults  of  all  but  his  fellow-men 

13.   Man  is  further  remarkable  for  his  power  of  adaptation  to  varieties  in  ex 
ternal  condition,  which  renders  him  to  a  great  extent  independent  of  them.     He 
is  capable  of  sustaining  the  highest  as  well  as  the  lowest  extremes  of  temperature 
and  of  atmospheric  pressure.     In  the  former  of  these  particulars,  he  is  strikingly 


44  HUMANPHYSIOLOGY. 

contrasted  with  the  anthropoid  Apes;  the  Chimpanzees  being  restricted  to  the 
hottest  parts  of  Africa,  and  the  Orang  Outan  to  the  tropical  portions  of  the  In- 
dian Archipelago;  and  neither  of  these  animals  being  capable  of  living  in  tem- 
perate climates  without  the  assistance  of  artificial  heat,  even  with  the  aid  of  which 
they  have  not  hitherto  long  survived  their  second  dentition.  So  again,  although 
Man's  diet  seems  naturally  of  a  mixed  character,  he  can  support  himself  in  health 
and  strength,  either  on'an  exclusively  vegetable  diet,  or,  under  particular  circum- 
stances, on  an  almost  exclusively  animal  regimen. 

14.  The  slow  growth  of  Man,  and  the  length  of  time  during  which  he  remains 
in  a  state  of  dependence,  are  peculiarities  that  remarkably  distinguish  him  from 
all  other  animals.     He  is  unable  to  obtain  his  own  food,  during  at  least  the  first 
three  years  of  his  life;  and  he  does  not  attain  to  his  full  bodily  stature  and  mental 
capacity,  until  he  is  more  than  twenty  years  of  age.     This  retardation  of  the 
developmental  process  seems  to  have  reference  to  the  high  grade  which  it  is  ulti- 
mately to  attain;    for  everywhere,  throughout  the  Organized  Creation,  do  we 
observe  that  the  most  elevated  forms  are  those  which  go  through  the  longest 
preparatory  stages,  and  of  which  the  evolution  is  most  dependent  upon  the  assist- 
ance afforded  by  the  parental  organism  during  its  earlier  periods.     The  peculiar 
prolongation  of  this  state  of  dependence  in  the  Human  species,  has  a  most  im- 
portant and  evident  effect  upon  the  social  condition  of  the  race ;  being,  in  fact, 
the  chief  source  of  family  ties,  and  affording  the  opportunity  for  those  processes 
of  education,  direct  and  indirect,  which  transmit  to  the  rising  generation  the 
influence  of  the  intellectual  culture  and  moral  training  of  the  past. 

15.  Still,  however  widely  Man  may  be  distinguished  from  other  animals  by 
these  and  other  particulars  of  his  structure  and  economy,  he  is  yet  more  distin- 
guished by  those  mental  endowments,  and  by  the  habitudes  of  life  and  action 
thence  resulting,  which  must  be  regarded  as  the  essential  characteristics  of  hu- 
manity.   It  is  in  adapting  himself  to  the  conditions  of  his  existence,  in  providing 
himself  with  food,  shelter,  weapons  of  attack  and  defence,  &c.,  that  Man's  intel- 
lectual powers  are  first  called  into  active  operation;  and  when  thus  aroused,  their 
development  has  no  assignable  limit.     The  Will,  guided  by  the  intelligence,  and 
acted  on  by  the  desires  and  emotions,  takes  the  place  in  man  of  the  Instinctive 
propensities,  which  are  the  usual  springs  of  action  in  the  lower  animals ;  and 
although  among  the  most  elevated  of  these,  a  high   amount  of   Intelligence 
is    exhibited,   yet    its    operations    seem   to   be    always    directly  attributable    to 
external   suggestions,  present   or  remembered ;    and  the    character   never  rises 
beyond  that  of  the  child.     In  fact,  the  correspondence  between  the  psychical 
endowments  of  the  Chimpanzee,  and  those  of  a  Child  of  three  years  old  who  has 
not  yet  begun  to  speak,  is  very  close.     One  of  the  most  important  aids  in  the 
use  and  development  of  the  Human  Mind,  is  the  capacity  for  articulate  speech; 
of  which,  so  far  as  we  know,  Man  is  the  only  animal  in  possession.     There  is  no 
doubt  that  many  other  species  have  certain  powers  of  communication  between 
individuals;  but  these  are  probably  very  limited,  and  of  a  kind  more  allied  to 
"  the  language  of  signs,"  than  to  a  proper  verbal  language.     In  fact,  it  is  obvious 
that  the  use  of  a  language  composed  of  a  certain  number  of  distinct  sounds,  com- 
bined into  words  in  a  multitude  of  different  modes,  requires  a  certain  power  of 
abstraction  and  generalization,  in  which  it  appears  that  the  lower  animals  are 
altogether  deficient.     So,  again,  verbal  language  affords  the  only  means  whereby 
abstract  ideas  can  be  communicated;  and  those  who  have  perused  the  interesting 
narrative  given  by  Dr.  Howe  of  his  successful  training  of  Laura  Bridgman,  will 
remember  how  marked  was  the  improvement  in  her  mental  condition,  from  the 
time  when  she  first  apprehended  the  fact  that  she  could  give  such  expression  to 
her  thoughts,  feelings,  and  desires,  as  should  secure  their  being  comprehended 
by  others. 

16.  The  capacity  for  intellectual  progress  is  a  most  remarkable  peculiarity  of 
Man's  psychical  nature.     The  instinctive  habits  of  the  lower  animals  are  limited. 


DISTINCTIVE     CHARACTERISTICS     OF     MAN.  45 

are  peculiar  to  each  species,  and  have  immediate  reference  to  their  bodily  wants. 
Where  a  particular  adaptation  of  means  to  ends,  of  actions  to  circumstances,  is 
made  by  an  individual,  the  rest  do  not  seem  to  profit  by  that  experience ;  so  that, 
although  the  instincts  of  particular  animals  may  be  modified  by  the  training  of 
man,  or  by  the  education  of  circumstances,  so  as  to  show  themselves  after  a  few 
generations  under  new  forms,  no  elevation  in  intelligence  appears  ever  to  take 
place  spontaneously,  no  psychical  improvement  is  manifested  in  the  species  at 
large.  In  Man,  on  the  other  hand,  we  observe  not  merely  the  capability  of  pro- 
fiting by  experience,  but  the  determination  to  do  so ;  which  he  is  enabled  to  put 
into  action,  by  the  power  which  his  Will  (when  properly  disciplined)  comes  to 
possess,  of  directing  and  controlling  his  current  of  thought,  by  fixing  his  atten- 
tion upon  any  subject  which  he  desires  to  keep  before  his  mental  vision.  This 
power,  so  far  as  we  know,  is  peculiar  to  Man;  and  the  presence  or  absence  of  it 
constitutes,  as  will  be  shown  hereafter  (CHAP.  XI.),  the  difference  between  a  being 
.possessed  of  power  to  determine  his  own  course  of  thought  and  action,  and  a 
mere  thinking  automaton. 

17.  Man's  capacity  for  progress  is  connected  with  another  element  in  his  na- 
ture, which  it  is  difficult  to  isolate  and  define,  but  which  interpenetrates  and 
blends  with  his  whole  psychical  character.  "  The  Soul,"  it  has  been  remarked, 
"  is  that  side  of  our  nature  which  is  in  relation  with  the  infinite;"  and  it  is  the 
existence  of  this  relation,  in  whatever  way  we  may  describe  it,  which  seems  to 
constitute  one  of  the  most  distinctive  peculiarities  of  Man.  It  is  in  the  desire  for 
an  improvement  in  his  condition,  occasioned  by  an  aspiration  after  something 
nobler  and  purer,  that  the  main-spring  of  human  progress  may  be  said  to  lie; 
among  the  lowest  races  of  mankind,  the  capacity  exists,  but  the  desire  seems  dor- 
mant. When  once  thoroughly  awakened,  however,  it  seems  to  "grow  by  what  it 
feeds  on  :"  and  the  advance  once  commenced,  little  external  stimulus  is  needed; 
for  the  desire  increases  at  least  as  fast  as  the  capacity.  In  the  higher  grades  of 
mental  development,  there  is  a  continual  looking-upwards,  not  (as  in  the  lower) 
towards  a  more  elevated  human  standard,  but  at  once  to  something  beyond  and 
above  man  and  material  nature.  This  seems  the  chief  source  of  the  tendency  to 
believe  in  some  unseen  existence ;  which  may  take  various  forms,  but  which  seems 
never  entirely  absent  from  any  race  or  nation,  although,  like  other  innate  tenden- 
cies, it  may  be  deficient  in  individuals.  Attempts  have  been  made  by  some 
travellers  to  prove  that  particular  nations  are  destitute  of  it ;  but  such  assertions 
have  been  based  only  upon  a  limited  acquaintance  with  their  habits  of  thought, 
and  with  their  outward  observances ;  for  there  are  probably  none  who  do  not  pos- 
sess the  idea  of  some  invisible  Power,  external  to  themselves,  whose  favor  they 
seek,  and  whose  anger  they  deprecate,  by  sacrifice  and  other  ceremonials.  It 
requires  a  higher  mental  cultivation  than  is  commonly  met  with,  to  conceive  of 
this  Power  as  having  a  Spiritual  existence ;  but  wherever  the  idea  of  spirituality 
can  be  defined,  this  seems  connected  with  it.  The  vulgar  readiness  to  believe  in 
ghosts,  demons,  &c.,  is  only  an  irregular  or  depraved  manifestation  of  the  same 
tendency.  Closely  connected  with  it,  is  the  desire  to  participate  in  this  spiritual 
existence ;  of  which  the  germ  has  been  implanted  in  the  mind  of  Man,  and  which, 
developed  as  it  is  by  the  mental  cultivation  that  is  almost  necessary  for  the  for- 
mation of  the  idea,  has  been  regarded  by  philosophers  in  all  ages  as  one  of  the 
chief  natural  arguments  for  the  immortality  of  the  soul.  By  this  immortal  soul, 
Man  is  connected  with  that  higher  order  of  being,  in  which  Intelligence  exists, 
unrestrained  in  its  exercise  by  the  imperfections  of  that  corporeal  mechanism 
through  which  it  here  operates;  and  to  this  state,  —  a  state  of  more  intimate 
communion  of  mind  with  mind,  and  of  creatures  with  their  Creator,  —  he  Ls 
encouraged  to  aspire,  as  the  reward  of  his  improvement  of  the  talents  here  com- 
mitted to  his  charge. 


46  GENERAL    VIEW    OP    THE     HUMAN    FUNCTIONS. 


CHAPTER  II. 

GENERAL   VIEW   OF   THE   FUNCTIONS   OF   THE   HUMAN   BODY. 
1.    Of  the  Mutual  Dependence  of  its  Vital  Actions. 

18.  THE  idea  of  Life,  in  its  simplest  acceptation,  is  that  of  Vital  Activity,  and 
obviously,  therefore,  involves  that  of  change.     We  do  not  consider  any  being  as 
olive,  which  is  not  undergoing  some  continual  alteration,  however  slow  and  ob- 
scure, that  may  be  rendered  perceptible  to  the  senses.1     This  alteration  may  be 
evidenced  by  the  growth  and  extension  of  the  organic  structure,  or  by  molecular 
changes  in  its  substance  which  do  not  produce  any  ostensible  increase ;  or  it  may 
be  most  obviously  manifested  in  movements  such  as  cannot  be  attributed  to  any 
physical  cause.     The  Life  of  any  complex  organism,  such  as  that  of  Man,  is  in 
fact  the  aggregate  of  the  Vital  Activity  of  all  its  component  parts ;  and  no  fact 
has  been  more  clearly  ascertained  by  modern  Physiological  research,  than  this, — 
that  each  elementary  part  of  the  fabric  has  its  own  independent  power  of  growth 
and  development,  that  it  has  its  own  proper  term  of  existence,  and  that  it  goes 
through  its  own  sequence  of  vital  actions,  in  virtue  of  the  endowments  which  it 
derived  from  the  tissue  that  evolved  it,  and  of  the  influences  to  which  it  is  sub- 
jected during  the  progress  of  its  existence.     Not  only  might  this  mutual  inde- 
pendence be  inferred  from  general  considerations;  its  existence  is  easily  proved 
by  observation  and  experiment.     There  are  a  variety  of  cases  in  which  the  "  mole- 
cular" life  of  individual  parts  remains,  long  after  u  somatic"  death  (or  death  of 
the  body  as  a  whole)  has  taken  place   (CHAP,  xix) ;   and  not  only  may  vital 
activity  be  sustained  in  a  part  completely  separated  from  the  body,  by  the  main- 
tenance of  the  circulation  of  blood  through  it,  but  vital  endowments  which  had 
partially  or  completely  ceased  to  manifest  themselves  in  consequence  of  the  ces- 
sation of  the  circulation,  may  be  restored  by  its  re-establishment.    The  occasional 
reunion   of  a  member  which   has  been   entirely  separated,  when   decomposing 
changes  have  not  yet  commenced  in  it,  most  clearly  shows,  that  nothing  but  the 
restoration  of  its  current  of  blood  is  requisite  for  the  preservation  of  its  vitality, 
and  that  its  powers  of  growth  and  renovation  are  inherent  in  itself,  only  requiring 
a  due  supply  of  the  nutrient  material,  with  certain  other  concurrent  conditions. 

19.  But  in  every  living  structure  of  a  complex  nature,  whilst  we  witness  a 
great  variety  of  actions,  resulting  from  the  exercise  of  the  different  powers  of  its 
several  component  parts,  we  at  the  same  time  perceive  that  there  is  a  certain  har- 
mony or  co-ordination  amongst  them  all,  whereby  they  are  all  made  to  concur  in 
the  maintenance  of  the  Life  of  the  Organism  as  a  whole.     And  if  we  take  a 
general  survey  of  them,  with  reference  to  their  mutual  relations  to  each  other,  we 

1  If  change  be  essenti.il  to  our  idea  of  life,  it  may  be  asked  what  is  the  condition  of  a 
Seed,  which  may  remain  unaltered  during  a  period  of  many  centuries ;  vegetating  at  last 
when  placed  in  favorable  circumstances,  as  if  it  had  only  ripened  the  year  before.  Such  a 
seed  is  not  alive :  for  it  is  not  performing  any  vital  operations.  But  it  is  not  dead,  for  it 
has  undergone  no  disintegration ;  and  it  is  still  capable  of  being  aroused  into  active  life, 
by  the  application  of  the  appropriate  stimuli.  The  most  correct  designation  of  its  state 
seems  to  be  dormant  vitality.  The  condition  of  an  Animal  reduced  to  a  state  of  complete 
torpidity  and  inaction  is  precisely  analogous ;  into  such  a  condition,  the  Frog  may  be 
brought  by  cold,  and  the  Wheel-animalcule  by  desiccation.  (See  PRING.  OF  GEN.  PHYS. 
Am.  Ed.)  And  the  condition  of  a  Human  being,  during  sleep,  is  precisely  similar,  so  far 
as  his  psychical  powers  are  concerned :  he  is  not  then  a  feeling,  thinking  Man  ;  but  he  is 
capable  of  feeling  and  thinking  when  his  brain  is  restored  to  a  state  of  activity,  and  ita 
powers  are  called  into  operation  by  the  impressions  of  external  objects. 


MUTUAL     DEPENDENCE     OF    THE     VITAL     ACTIONS.       47 

shall  perceive  that  they  may  be  associated  into  groups ;  each  consisting  of  a  set 
of  actions,  which,  though  differing  among  themselves,  concur  in  effecting  some 
positive  and  determinate  purpose.  These  groups  of  actions  are  termed  Functions. 
—  Thus,  one  of  the  most  universal  of  all  the  changes  necessary  to  the  continued 
existence  of  a  living  being,  is  the  exposure  of  its  nutritious  fluid  to  the  air ;  by 
the  action  of  which  upon  it,  certain  alterations  are  effected.  For  the  performance 
of  this  aeration,  simple  as  the  change  appears,  many  provisions  are  required.  In 
the  first  place,  there  must  be  an  aerating  surface,  consisting  of  a  thin  membrane, 
permeable  to  gn*es ;  on  the  one  side  of  which  the  blood  may  be  spread  out,  whilst 
the  air  is  in  contact  with  the  other.  Then  there  must  be  a  provision  for  continu- 
ally renewing  the  blood  which  is  brought  to  this  surface ;  in  order  that  the  whole 
mass  of  fluid  may  be  equally  benefited  by  the  process.  And,  in  like  manner,  the 
stratum  of  air  must  also  be  renewed,  as  frequently  as  its  constituents  have  under- 
gone any  essential  change.  We  include,  therefore,  in  speaking  of  the  '  Function 
of  Respiration,'  not  only  the  actual  aerating  process,  but  also  the  various  changes 
which  are  necessary  to  carry  this  into  effect,  and  which  obviously  have  it  for 
their  ultimate  purpose. 

20.  On  further  examining  and  comparing  these  Functions,  we  find  that  they 
are  themselves  capable  of  some  degree  of  classification.  Indeed  the  distinction 
between  the  groups  into  which  they  may  be  arranged,  is  one  of  essential  im- 
portance in  Animal  Physiology.  If  we  contemplate  the  history  of  the  Life  of  a 
Plant,  we  perceive  that  it  grows  from  a  germ  to  a  fabric  of  sometimes  gigantic 
size,  —  generates  a  large  quantity  of  organized  structure,  as  well  as  many  organic 
compounds,  which  form  the  products  of  secretion,  but  which  do  not  undergo 
organization,  —  arid  multiplies  its  species,  by  the  production  of  germs  similar  to 
that  from  which  it  originated;  —  but  that  it  performs  all  these  complex  opera- 
tions, without  (so  far  as  we  can  perceive)  either  feeling  or  thinking,  without  con- 
sciousness or  will.  All  the  functions  of  which  its  Life  is  composed,  are,  there- 
fore, grouped  together  under  the  general  designation  of  Functions  of  Organic  or 
Vegetative  life";  and  they  are  subdivided  into  those  concerned  in  the  development 
and  maintenance  of  the  structure  of  the  individual,  which  are  termed  functions 
of  Nutrition,  and  those  to  which  the  Reproduction  of  the  species  is  due.  —  The 
great  feature  of  the  Nutritive  operations  in  the  Plant,  is  their  constructive  charac- 
ter. They  seem  as  if  destined  merely  for  the  building-up  and  extension  of  the 
fabric;  and  to  this  extension  there  seems  in  some  cases  to  be  no  determinate 
limit.  But  it  is  very  important  to  remark,  that  the  growth  of  the  more  perma- 
nent parts  of  the  structure  is  only  attained  by  the  continual  development,  decay, 
and  renewal  of  parts,  whose  existence  is  temporary.  No  fact  is  better  established 
in  Vegetable  Physiology,  than  the  dependence  of  the  formation  of  wood  upon  the 
action  of  the  leaves.  It  is  in  their  cells  that  those  important  changes  are  effected 
in  the  sap,  by  which  it  is  changed,  from  a  crude  watery  fluid  containing  very  little 
solid  matter,  to  a  viscid  substance  including  a  great  variety  of  organic  compounds, 
destined  for  the  nutrition  of  the  various  tissues.  The  '  fall  of  the  leaf  results 
merely  from  the  death  and  decay  of  its  tissue ;  as  is  evident  from  the  fact,  that, 
for  some  time  previously,  its  regular  functions  cease,  and  that  instead  of  a  fixation 
of  carbon  from  the  atmosphere,  there  is  a  liberation  of  carbonic  acid  (a  result  of 
their  decomposition)  in  large  amount.1  Now  this  process  takes  place  no  less  in 
'evergreens'  than  in  'deciduous'  trees;  the  only  difference  being,  that  the  leaves 
in  the  latter  are  all  cast-off  arid  renewed  together,  whilst  in  the  former  they  are 
continually  being  shed  and  replaced,  a  few  at  a  time.  It  appears  as  if  the  nutri- 
tious fluid  of  the  higher  Plants  can  only  be  prepared  by  the  agency  of  cells  whose 
duration  is  brief;  for  we  have  no  instance  in  which  the  tissue  concerned  in  its  elabo- 
ration possesses  more  than  a  very  limited  term  of  existence.  But  by  its  active 
vital  operations,  it  produces  a  fluid  adapted  for  the  nutrition  of  parts  which  are 

1  See  "Principles  of  Comparative  Physiology/'  \\  265,  339.— Am.  Ed. 


48  GENERAL    VIEW    OF    THE    HUMAN     FUNCTIONS. 

of  a  much  more  solid  and  permanent  character,  and  which  undergo  little  change 
of  any  kind  subsequently  to  their  complete  development;  this  want  of  tendency 
to  decay  being  the  result  of  the  very  same  peculiarity  of  constitution,  as  that  which 
renders  them  unfit  to  participate  in  the  proper  vital  phenomena  of  the  organism. 
Thus  the  final  cause  or  purpose  of  all  the  Nutritive  functions  of  the  Plant,  so  far 
as  the  individual  is  concerned,  is  to  produce  an  indefinite  extension  of  the  dense, 
woody,  almost  inert,  and  permanent  portions  of  the  fabric,  by  the  continued  de- 
velopment, decay,  and  renewal  of  the  soft,  active,  and  transitory  cellular  paren- 
chyma.—  The  Nutritive  functions,  however,  also  supply  the  materials  for  the 
continuance  of  the  race,  by  the  generation  of  new  individuals;  since  a  fresh  germ 
cannot  be  formed,  any  more  than  the  parent  structure  can  be  extended,  without 
organizable  materials,  prepared  by  the  assimilating  process,  and  supplied  to  the 
parts  in  which  active  changes  are  going  on. 

21.  On  analysing  the  operations  which  take  place  in  the  Animal  body,  we  find 
that  a  large  number  of  them  are  of  essentially  the  same  character  with  the  fore- 
going, and  differ  only  in  the  conditions  under  which  they  are  performed ;  so  that 
we  may,  in  fact,  readily  separate  the  Organic  functions,  which  are  directly  con- 
cerned in  the  development  and  maintenance  of  the  fabric,  from  the  Animal  func- 
tions, which  render  the  individual  conscious  of  external  impressions,  and  capable 
of  executing  spontaneous  movements.     The  relative  development  of  the  organs 
destined  to  these  two  purposes,  differs  considerably  in  the  several  groups  of  Ani- 
mals.    The  life  of  a  Zoophyte  is  upon  the  whole  much  more  l  vegetative'  than 
'  animal ;'  and  we  perceive  in  it,  not  merely  the  very  feeble  development  of  those 
powers  which  are  peculiar  to  the  Animal  kingdom,  but  also  that  tendency  to 
indefinite  extension  which  is  characteristic  of  the  Plant.     In  the  Insect  we  have 
the  opposite  extreme ;  the  most  active  powers  of  motion,  and  sensations  of  which 
some  (at  least)  are  very  acute,  coexisting  with  a  low  development  of  the  organs 
of  nutrition.   In  Man  and  the  higher  classes  generally,  we  have  less  active  powers 
of  locomotion,  but  a  much  greater  variety  of  Animal  faculties;  and  the  instru- 
ments of  the  Organic  or  nutritive  operations  attain  their  highest  development, 
and  their  greatest  degree  of  mutual  dependence.  In  the  fabric  of  all  beings  whose 
Animal  powers  are  much  developed,  we  see  an  almost  entire  want  of  that  tendency 
to  indefinite  extension,  which  is  so  characteristic  of  the  Plant ;  and  when  the 
large  amount  of  food  consumed  by  them  is  considered,  the  questions  naturally 
arise,  to  what  purpose  this  food  is  applied  ?  and  what  is  the  necessity  for  the  con- 
tinued activity  of  the  Organic  functions,  when  once  the  body  has  attained  the 
limits  of  its  development  ? 

22.  The  answer  to  these  questions  lies  in  the  fact,  that  the  exercise  of  the 
Animal  functions  is  essentially  destructive  of  their  instruments ;  every  operation 
of  the  Nervous  and  Muscular  systems  involving,  as  its  necessary  condition,  a 
disintegration  of  a  certain  part  of  their  tissues ;  so  that  the  duration  of  the  ex- 
istence of  those  tissues  varies  inversely  to  the  use  that  is  made  of  them,  being 
less  as  their  functional  activity  is  greater.     A  compensating  operation  of  the 
constructive  functions  is  therefore  required,  in  order  to  repair  the  loss  of  sub- 
stance thus  occasioned ;  from  which  it  happens  that  the  demand  for  nutrition 
(and  therefore  the  necessity  for  food)  is  in  great  degree  regulated  by  the  func- 
tional  activity  of   the  nervo-muscular   apparatus.  —  We    are    not,  however,  to 
measure  the  activity  of  the  Nervous  system,  like  that  of  the  Muscular,  only  by 
the  amount  of  movement  to  which  it  gives  origin.     For  there  is  equal  evidence, 
that  the  demand  for  blood  in  the  Brain,  the  amount  of  nutrition  it  receives,  and 
the  degree  of  disintegration  it,  undergoes,  are  proportional  likewise  to  the  energy 
of  the  purely  psychical  operations;  so  that  the  vigorous  exercise  of  the  intellec- 
tual powers,  or  a  long-continued  state  of  agitation  of  the  feelings,  produces  as 
great  a  '  waste '  of  Nervous  matter  as  is  occasioned  by  active  bodily  exercise.  — 
But  further,  in  the  performance  of  the  Organic  functions  of  Animals  (thus  called 
into  activity  for  ulterior  purposes),  there  is,  no  less  than  ill  the  Vegetative  life 


MUTUAL    DEPENDENCE    f*F    THE    VITAL    FUNCTIONS.      4!) 

of  a  Plant  (which  begins  and  ends  with  itself),  a  continued  production,  decay, 
exuviation,  and  renewal,  of  the  cells  by  whose  instrumentality  many  of  the  most 
important  changes  are  effected.  This  successional  loss  and  replacement  of  the 
most  important  components  of  the  nutritive  system  of  the  Animal,  is  a  phenome- 
non really  not  less  intimately  related  to  its  functional  activity,  than  is  that  of  the 
leaves  in  the  Plant  (§  20);  but  it  takes  place  in  the  penetralia  of  the  system,  in 
such  a  manner  as  to  elude  observation,  except  that  of  the  most  scrutinizing  kind ; 
and  it  has  been  in  bringing  this  into  view,  that  the  Microscope  has  rendered  one 
of  its  most  valuable  services  to  Physiology. 

23.  In  the  Animal  fabric,  then,  among  the  higher  classes  at  least,  the  function 
or  purpose  of  the  organs  of  Vegetative  life  is  not  so  much  the  extension  of  the 
fabric,  for  this  has  certain  definite  limits,  as  the  maintenance  of  its   integrity,  by 
the  reparation  of  the  destructive  effects  of  the  exercise  of  the  purely  Animal  powers. 
By  the  operations  of  Digestion,  Assimilation,  and  Circulation,  the  nutritive  ma- 
terials are  prepared,  and  are  conveyed  to  the  points  where  they  are  required ;  the 
Circulation  of  aerated  blood  also  serves  to  transmit  oxygen,  which  is  introduced 
by  the  Respiratory  process ;  and  it  has  further  for  its  office,  to  convey  away  the 
products  of  that  decomposition  of  the  Muscular  and  Nervous  tissues,  which  re- 
sults from  their  functional  activity,  these  products  being  destined  to  be  separated 
by  the  Respiratory  and  other  Excreting  operations.     The  regular  maintenance  of 
the  functions  of  Animal  life  is  thus  entirely  dependent  upon  the  due  performance 
of  the  Nutritive  operations  ;  a  consideration  of  great  importance  in  practice,  since 
a  very  large  proportion  of  what  are  termed  l  functional  disorders'  (of  the  Nervous 
system  especially)  are  immediately  dependent  upon  some  abnormal  condition  of 
the  Blood. 

24.  But  there  also  exists  a  connection  of  an  entirely  reverse  kind,  between 
the  Organic  and  the  Animal  functions;  for  the  conditions  of  Animal  existence 
render  the  former  in  great  degree  dependent  on  the  latter.     In  the  acquisition 
of  food,  for  example,  the  Animal  has  to  make  use  of  its  senses,  its  psychical 
faculties,  and  its  power  of  locomotion,  to  obtain  that  which  the  Plant,  from  the 
different  provision  made  for  its  support,  can  derive  without  any  such  assistance; 
moreover,  for  the  ingestion  of  the  food,  and  for  its  propulsion  along  the  aliment- 
ary canal,  Muscular  action  is  required,  this  being  employed  under  the  direction 
of  Nervous  agency  at  the  oral  and  anal  orifices;  and  thus  we  see  that  the  change 
in  the  conditions  required  for  the  appropriation  of  food  by  animals,  has  rendered 
necessary  the  introduction  of  additional  elements  into  the  apparatus,  to  which 
nothing  comparable  was  to  be  found  in  Plants.     Again,  in  the  function  of  Respi- 
ration, as  performed  in  Man  and  the  higher  animals,  the  Nervous  and  Muscular 
systems  are  alike  involved ;  for  the  movements  by  which  the  air  in  the  lungs  is 
being  continually  renewed,  are  dependent  upon  the  action  of  both ;  and  those  by 
which  the  blood  is  propelled  through  the  respiratory  organs,  are  chiefly  occasioned 
by  the  contractility  of  a  muscular  organ,  the  heart.     Such  movements,  however, 
as  are  thus  immediately  connected  with  the  maintenance  of  the  Organic  functions, 
do  not  depend  upon  the  will,  and  may  even  be  performed  without  our  conscious- 
ness; they  can  scarcely  be  regarded,  therefore,  as  forming  part  of  our  propei 
Animal  life;  and  th-e  only  essential  difference  which  they  present,  from  those 
which  are  occasionally  performed  by  Plants  (especially  such  as  exhibit  the  trans- 
mission of  the  effect  of  a  stimulus  to  some  distance,  —  the  folding  of  the  leaves 
of  the  Mimosa,  or  the  closure  of  the  fly-trap  of  the  Dionaea,  for  example),  con- 
sists in  the  instrumentality  through  which  they  are  performed,  —  this  being  in 
Animals  a  peculiar  Nervous  and  Muscular  apparatus,  whilst  in  Plants  it  is  only  a 
modification  of  the  ordinary  structure. 

25.  From  what  has  been  said,  then,  it  appears  that  all  the  functions  of  the 
Animal  body  are  so  completely  bound  up  together  that  none  can  be  suspended 
without  the  cessation  of  the  rest.     The  properties  of  all  the  tissues  and  organs 
arc  dependent  upon  their  regular  Nutrition,  by  a  due  supply  of  perfectly  elabo 

4 


50  GENERAL    VIEW    OF    THE    HUMAN    FUNCTIONS. 

rated  blood;  tins  cannot  be  effected,  unless  the  functions  of  Circulation,  Respi- 
ration, and  Excretion,  be  performed  with  regularity,  —  the  first  being  necessary 
to  distribute  the  supply  of  nutritious  fluid,  the  second  being  requisite  for  its 
oxygenation,  and  being  also  needed,  in  conjunction  with  the  third,  to  free  it  from 
the  impurities  which  it  contracts  during  its  circuit.  The  Respiration  cannot  be 
maintained,  without  the  integrity  of  a  certain  part  of  the  Nervo-muscular  appa- 
ratus; and  the  due  action  of  this,  again,  is  dependent  not  only  upon  its  regular 
nutrition,  but  also  upon  its  supply  of  oxygen.  The  materials  necessary  for  the 
replacement  of  those  which  are  continually  being  separated  from  the  blood,  can 
only  be  derived  through  the  Absorption  of  ingested  aliment;  and  this  cannot  be 
accomplished  without  the  preliminary  process  of  Digestion.  The  introduction 
of  food  into  the  stomach,  again,  is  dependent,  like  the  actions  of  Respiration, 
upon  the  operations  of  the  muscular  apparatus  and  of  a  part  of  the  nervous 
centres;  and  the  previous  acquirement  of  food  necessarily  involves  the  purely 
Animal  powers. — Now  it  will  serve  to  show  the  distinction  between  these  powers 
and  those  which  are  merely  subservient  to  Organic  life,  if  we  advert  to  the  case, 
which  is  of  no  unfrequent  occurrence,  of  a  Human  being,  deprived  (as  in  apo- 
plectic coma)  by  some  morbid  condition  of  the  brain,  of  all  the  powers  of  Animal 
life,  sensation,  thought,  volition,  &c.,  and  yet  capable  of  maintaining  a  Vegeta- 
tive existence,  in  which  all  the  organic  functions  go  on  as  usual ;  that  division 
of  the  nervous  system  which  is  concerned  in  the  movements  whereon  some  ot 
these  depend,  not  being  yet  affected  by  the  morbid  influence.  It  is  evident  that 
we  can  assign  no  definite  limits  to  such  a  state,  so  long  as  the  respiratory  move- 
ments are  sustained,  and  the  necessary  food  is  placed  within  reach  of  the  grasp 
of  the  muscles  that  will  convey  it  into  the  stomach  :  as  a  matter  of  fact,  how- 
ever, it  is  seldom  of  long  continuance,  since  the  disordered  state  of  the  brain  is 
sure  to  extend  itself,  sooner  or  later,  to  the  rest  of  the  nervous  system.  Thib 
condition  may  be  experimentally  imitated  by  the  removal  of  the  brain,  in  many 
of  the  lower  animals,  whose  bodies  will  sustain  life  for  many  months  after  such 
a  mutilation  ;  but  this  can  only  take  place  when  that  food  is  conveyed  by  external 
agency  within  the  pharynx,  which  they  would,  if  in  their  natural  condition,  have 
obtained  for  themselves.  A  similar  experiment  is  sometimes  made  by  Nature  for 
the  Physiologist,  in  the  production  of  foetuses,  as  well  of  the  human  as  of  other 
species,  in  which  the  brain  is  absent;  these  can  breathe,  suck,  and  swallow,  and 
perform  all  their  organic  functions ;  and  there  is  no  assignable  limit  to  their  ex- 
istence, so  long  as  they  are  duly  supplied  with  food.1  —  Hence  we  may  learn  the 
exact  nature  of  the  dependence  of  the  Organic  functions  upon  those  of  purely 
Animal  life ;  and  we  perceive  that,  though  less  immediate  than  it  is  upon  the 
simple  excito-motor  actions  of  the  nervous  and  muscular  systems,  it  is  not  less 
complete.  On  the  other  hand,  the  functions  of  Animal  life  are  even  more  closely 
dependent  upon  the  nutritive  actions,  than  are  those  of  organic  life  in  general ; 
for  many  tissues  will  retain  their  several  properties  and  their  power  of  growth 
and  extension,  for  a  much  longer  period  after  a  general  interruption  of  the  circu- 
lation, than  will  the  Nervous  structure ;  which  is,  indeed,  instantaneously  affected 
by  a  cessation  of  the  due  supply  of  blood,  or  by  the  depravation  of  its  quality. 

2.  Functions  of  Vegetative  Life. 

26.  As  a  certain  change  of  composition  of  the  Organized  fabric  is  a  necessary 
condition  of  every  manifestation  of  its  Vital  activity,  it  is  obviously  requisite  that 

1  A  very  remarkable  case  was  mentioned  to  the  Author  by  his  friend  the  late  Mr.  Wallis, 
of  Hull;  the  subject  of  which  had  never,  from  the  time  of  his  birth,  exhibited  any  distinct 
indication  of  consciousness,  and  had  yet,  by  sedulous  care,  been  reared  to  the  age  of  ten 
years.  There  was  no  appearance  of  any  malformation  about  the  Brain,  and  jet  it  must 
obviously  have  been  functionally  inactive ;  for  no  movements  were  ever  witnessed,  which 
seemed  to  proceed  from  any  higher  centre  than  the  Medulla  Oblongata.  Even  in  the 
administration  of  nourishment,  it  was  necessary  that  the  food  should  be  carried  back  into 
'he  pharynx,  so  that  it  might  be  grasped  by  the  reflex  action  of  its  constrictors. 


FUNCTIONS     OF    VEGETATIVE    LIFE.  51 

a  provision  should  exist  for  the  replacement,  by  new  matter,  of  all  those  particles 
which,  having  lost  their  vital  endowments,  are  in  process  of  return  to  the  condi- 
tion of  inorganic  matter.  And  hence,  of  course,  every  increase  in  the  activity 
of  the  Animal  functions  becomes  a  source  of  augmented  demand  for  nourish- 
ment ;  provided,  at  least,  that  such  increase  does  not  go  to  the  extent  of  exhaust- 
ing the  vital  energies,  and  thus  of  preventing  the  due  performance  of  the  Nutritive 
functions.  A  constant  supply  of  Aliment  is  therefore  needed  for  the  maintenance 
of  the  body,  after  it  has  arrived  at  its  full  development.  The  effects  of  the  pro- 
cess of  waste  and  decay,  uncompensated  by  that  of  renovation,  are  seen  in  starva- 
tion and  in  diseases  of  exhaustion  (§70-72);  in  which  there  is  a  gradual 
diminution  in  the  bulk  of  nearly  all  the  tissues  of  the  body,  so  that,  before  death 
supervenes,  the  total  reduction  in  weight  is  very  considerable.  —  But  in  the 
yrowing  state  of  the  organism  there  is,  of  course,  an  additional  demand  for  Ali- 
ment, to  supply  the  materials  for  the  extension  which  is  continually  taking  place 
in  it.  This,  however,  does  not  make  so  great  a  difference  as  it  might  appear  to 
do,  in  the  supply  of  food  which  is  required.  For  if  the  absolute  addition 
which  is  made  by  growth  to  the  body  in  any  given  time,  be  compared  with  the 
amount  of  change  of  composition  which  takes  plaee  in  the  the  same  period, — the 
latter  being  judged  of  by  the  quantity  of  food  consumed,  and  by  the  amount  of 
excrementitious  matter  which  passes  off  by  the  lungs,  liver,  kidneys,  skin,  &c., — 
it  will  be  found  to  bear  but  a  very  small  proportion  to  it.  The  fact  is  rather, 
that,  during  the  whole  period  of  growth,  there  is  (so  to  speak)  a  continual  re- 
modelling of  the  entire  fabric;  the  life  of  each  part  being  brief,  in  order  that  its 
renovation  may  be  effected  on  a  somewhat  different  scale.  And  thus  it  happens 
that  children  require  a  much  larger  amount  of  food  in  proportion  to  their  bulk, 
than  that  which  suffices  for  adults.  On  the  other  hand,  in  old  persons,  the  life 
of  each  part  is  comparatively  slow ;  its  vital  operations  are  deficient  in  activity ; 
and  the  processes  of  waste  and  the  demand  for  food  are  proportionally  retarded 
(CHAP.  xvin.). 

27.  But  another  and  most  important  source  of  demand  for  food,  in  Man  and 
warm-blooded  animals  generally,  arises  out  of  the  requirements  of  the  combustive 
process,  whereby  the  Heat  of  the  body  is  maintained.     This  demand  will  vary, 
cseteris  paribus,  with  the  amount  of  heat  to  be  generated,  which  bears  a  direct 
proportion  to  the  depression  of  the  external  temperature,  the  standard  of  the 
body  itself  being  fixed.     Hence  external  cold  comes  to  be  a  source  of  demand 
for  food;  whilst  artificial  warmth  may  be  made  to  take  the  place  of  the  nourish- 
ment otherwise  required  for  this  purpose ;  as  has  been  shown  by  the  remarkable 
experiments  of  Chossat  hereafter  to  be  referred  to  (§  70,  and  CHAP,  x.,  Sect.  2. — 
But  if  the  amount  of  exercise  taken  be  very  considerable,  especially  in  warm 
climates,  where  the  demand  for  the  production  of  Heat  is  reduced  to  its  mini- 
mum, a  sufficient  amount  of  pabulum  for  the  respiratory  process  may  be  provided 
by  the  disintegration  of  the  nervo-muscular  apparatus,  without  any  special  supply 
being  required. 

28.  The  demand  for  food  is  increased  by  any  cause  which  creates  an  unusual 
drain  or  waste  in  the  system.     Thus  an  extensive  suppurating  action  can  be  sus- 
tained only  by  a  large  supply  of  highly  nutritious  food.     The  mother,  who  has 
to  furnish  the  daily  supply  of  milk  which  constitutes  the  sole  support  of  her  off- 
spring, needs  an  unusual  sustenance  for  this  purpose.     And  there  are  states  of 
the  system,  in  which  the  solid  tissues  seem  to  possess  an  abnormal  tendency  to 
decomposition,  and  in  which  an  increased  supply  of  aliment  is  therefore  required. 
This  is  the  case,  for  example,  in  Diabetes;  one  of  the  first  symptoms  of  which 
disease  is  the  craving  appetite,  that  seems  as  if  it  would  be  never  satisfied.     And 
there  can  be  no  doubt  that,  putting  aside  all  the  other  circumstances  which  have 
been  alluded  to,  there  is  much  difference  amongst  individuals,  in  regard  to  the 
rapidity  of  the  changes  which  their  organism  undergoes,  and  the  amount  of  food 
consequently  required  for  its  maintenance. 


5L  GENERAL    VIEW    OF    THE    HUMAN    FUNCTIONS. 

29.  The  want  of  solid  aliment  is  made  known  by  the  feeling  of  Hunger;  and 
that  of  liquids,  by  the  feeling  of  Thirst.     These  feelings,  as  will  be  shown  here- 
after  (§§  66—69),   are   but   secondarily  dependent  upon   the    condition   of  the 
stomach ;  and  may  be  considered,  in  the  state  of  health,  as  tolerably  faithful 
indications  of  the  wants  of  the  body  at  large.     They  become  the  stimulants  to 
mental  operations,  having  for  their  object  the  gratification  of  the  desire,  by  the 
acquisition  of  food  or  drink.      In  the  state  of  Infancy,  the  actions  which  they 
prompt  are  obviously  automatic;  that  is,  they  are  performed  in  direct  respondence 
to  the  appropriate  stimulus,  and  do  not  involve  any  idea  of  purpose  or  object  on 
the  part  of  the  being  which  executes  them.     But  in  all  succeeding  periods  of 
life,  they  are  directed  by  intelligence ;  being  performed  with  a  design  or  purpo- 
sive adaptation  of  means  to  ends  which  are  clearly  before  the  consciousness. — 
The  reception  of  food  into  the  mouth,  and  its  preparation  by  the  acts  of  masti- 
cation and  insalivation,  would  seem  rather  to  belong  to  the  consensual  or  'sensori- 
motor'  class  of  movements;  being  performed  quite  independently  of  the  will, 
whenever  that  power  is  in  abeyance,  or  is  differently  directed.     By  these  move- 
ments the  aliment  is  brought  within  reach  of  the  pharyngeal  muscles,  whose  con- 
traction cannot  be  effected  by  the  will,  but  is  purely  reflex,  or  '  excito-motor,' 
resulting  merely  from  the  conveyance  to  the  Medulla  Oblongata  of  the  impression 
made  upon  the  fauces  by  the  contact  of  the  substance  swallowed,  and  from  the 
reflexion  of  an  influence  excited  by  that  impression  back  to  the  muscles.     By 
these  it  is  propelled  down  the  oesophagus;  and,  after  their  action  has  ceased,  it 
is  taken  up  (as  it  were)  by  the  muscular  coat  of  the  oesophagus  itself,  and  is 
conveyed  into  the  stomach.     How  far  the  movements  of  the  lower  parts  of  the 
oesophagus  and  of  the  stomach  are  in  Man  dependent  upon  reflex  action,  is  un- 
certain ;  the  facts  which  have  been  ascertained  en  this  point,  by  experiment  on 
animals,  will  be  detailed  in  their  proper  place  (§§  82,  84). 

30.  The  Food,  of  which  certain  components  are  altered  in  the  mouth  by  the 
chemical  action  of  the  saliva,  is  brought  in  the  stomach  under  the  influence  of 
the  gastric  secretion ;    the  chemical  action  of  which,  aided  by  the  constantly- 
elevated  temperature  of  the  interior  of  the  body,  and  by  the  continual  agitation 
effected  by  the  contractions  of  the  parietes  of  the  organ,  effects  a  more  or  less 
complete  reduction  of  it.     Some  of  its  nutritive  components,  being  actually  dis- 
solved by  the  gastric  juice,  are  thus  prepared  for  immediate  absorption  •  but  others 
require  the  admixture  of  the  biliary  and  pancreatic  secretions,  whereby  various 
changes  are  effected  in  their  condition,  which  prepare  them  also  for  being  re- 
ceived into  the  circulating  system.     The  nutritious  portion  being  gradually  taken 
up  by  the  Blood-vessels  and  by  the  Absorbent  vessels  (or  lacteals),  which  are 
distributed  on  the  walls  of  the  alimentary  canal,  the  indigestible  residue  is  pro- 
pelled along  the  intestinal  tube  by  the  simple  contractility  of  its  walls,  undergoing 
at  the  same  time  some  further  change,  by  which  the  nutritive  materials  are  still 
more  completely  extracted  from  it.     And  at  last  the  excrementitious  matter, — 
consisting  not  only  of  the  insoluble  portion  of  the  food  taken  into  the  stomach, 
but  also  of  part  of  the  secretion  of  the  liver,  and  of  that  of  the  mucous  surface 
of  the  intestines  and  of  their  glandular  follicles, — is  voided  from  the  opposite 
extremity  of  the  canal,  by  a  muscular  exertion,  which  is  partly  reflex,  like  that 
of  deglutition,  but  is  partly  voluntary,  especially  (as  it  would  appear)  in  Man. 
The  whole  of  this  series  of  operations,  by  which  the  nutritive  materials  are  pre- 
pared for  being  absorbed,  may  be   considered  as  constituting  the  function  of 
Digestion. 

31.  The  introduction  of  the  nutritive  materials  thus  prepared  into  the  vessels 
which  convey  them  to  the  tissues,  constitutes  the  function  of  Absorption.     But 
these  materials  undergo  important  changes  in  their  progress  towards  the  centre 
of  the  circulation,  whereby  they  are  brought  more  nearly  to  the  condition  of  true 
Blood;  and  these  changes  are  designated  by  the  term  Assimilation. — There  seems 
no  doubt  that  fluid  containing  saline,  albuminous,  or  other  matters  in  a  state  of 


FUNCTIONS     OF    VEGETATIVE    LIFE.  53 

complete  solution,  may  be  absorbed  by  the  Blood-vessels  with  which  the  mucous 
membrane  of  the  alimentary  canal  is  so  copiously  supplied  ;  and  this  simple 
process  of  imbibition  probably  takes  place  according  to  the  physical  laws  of  En- 
dosmose.  But  the  selection  and  absorption  of  some  of  the  nutritive  materials 
appear  to  be  performed,  not  by  vessels,  but  by  the  specific  vital  endowments  of  cells 
(§  121),  which  subsequently  yield  up  their  contents  to  the  Lacteals.  The  fluid 
thus  absorbed,  which  now  receives  the  name  of  Chyle,  is  propelled  through  the 
Lacteals  by  the  contractility  of  their  walls;  aided  in  part,  perhaps,  by  a  vis  a 
ferf/o  derived  from  the  force  of  the  absorption  itself. — With  the  reception  of  the 
nutritious  food  into  the  vessels  commences  its  real  preparation  for  Organization. 
Up  to  that  period  it  cannot  be  said  to  be  in  any  degree  vitalized;  the  change? 
which  it  has  undergone  being  only  of  a  chemical  and  physical  nature,  and  such 
as  merely  prepare  it  for  subsequent  assimilation.  But  in  the  passage  of  that 
which  has  been  taken  up  by  the  Blood-vessels  through  the  Liver,  very  important 
alterations  are  effected  in  its  condition,  whereby  it  is  brought  to  a  state  more 
nearly  corresponding  with  true  Blood.  And  in  like  manner  the  Chyle,  in  passing 
through  the  long  and  tortuous  system  of  absorbent  vessels  and  glands,  under- 
goes changes  which,  with  little  chemical  difference,  manifest  themselves  by  a 
decided  alteration  in  its  properties ;  so  that  the  chyle  of  the  Thoracic  duct  is 
evidently  a  very  different  fluid  from  the  chyle  of  the  Lacteals,  approaching  much 
nearer  to  blood  in  its  general  characters.  These  characters  are  such  as  indicate 
that  the  process  of  organization  and  vitalization  has  commenced;  as  may  be 
judged  alike  from  the  microscopic  appearance  of  the  fluid,  and  from  the  changes 
it  undergoes  when  removed  from  the  body.  The  Chyle  thus  modified  is  conveyed 
into  the  Sanguiferous  system  of  vessels,  in  which  it  is  mingled  with  the  general 
mass  of  the  Blood ;  and  it  flows  directly  to  the  heart,  by  which  it  is  transmitted 
to  the  lungs.  It  there  has  the  opportunity  of  absorbing  oxygen,  and  of  exhaling 
its  superfluous  carbonic  acid,  and  probably  acquires  gradually  the  properties  by 
which  the  previously-formed  blood  is  distinguished,  thus  becoming  the  pabulum 
vitas  for  the  whole  system. — The  fluid  which  is  brought  by  the  Lymphatic  system 
from  those  parts  of  the  organism  to  which  it  is  distributed,  is  obviously  of  a 
character  no  less  nutritive  than  the  chyle,  though  it  was  formerly  regarded  as 
excrementitious.  Its  source  appears  to  be  partly  in  the  serous  transudation  which 
escapes  from  the  blood-vessels  into  the  substance  of  the  tissues,  the  superfluity 
of  which  is  taken  up  again  and  carried  back  into  the  circulation  by  the  lym- 
phatics ;  and  partly,  it  may  be,  in  the  re-solution  of  such  portions  of  the  tissues 
themselves  as,  though  dead,  are  not  in  a  state  of  decomposition  that  prevents 
their  components  from  being  again  made  available  as  nutritive  materials.  The 
Lymph,  like  the  chyle,  seems  to  undergo  an  elaborating  process  in  its  passage 
towards  the  thoracic  duct,  whereby  it  is  gradually  assimilated  to  blood  in  its 
nature. 

32.  The  Circulation  of  the  Blood  through  the  tissues  and  organs  which  it  is 
destined  to  support,  is  a  process  evidently  necessary  alike  for  supplying  them 
with  the  nutritious  materials  which  are  provided  for  the  repair  of  their  waste,  and 
for  removing  those  elements  of  their  fabric  which  are  in  a  state  of  incipient  de- 
composition. In  the  lowest  classes  of  organized  beings,  every  portion  of  th(» 
structure  is  in  direct  relation  with  its  nutritive  materials;  it  can  absorb  for  itself 
that  which  is  required;  and  it  can  readily  part  with  that  of  which  it  is  desirable 
to  get  rid.  Hence,  in  such,  no  general  circulation  is  necessary.  In  Man> 
on  the  other  hand,  the  digestive  cavity  occupies  so  small  a  portion  of  the  body, 
that  the  organs  at  a  distance  from  it  have  no  other  means  than  their  vascular 
communication  affords  of  participating  in  the  products  of  its  operations;  and  it 
is  moreover  necessary  that  they  should  be  continually  furnished  with  the  organ- 
izable  materials,  of  which  the  occasional  operation  of  the  digestive  process  would 
otherwise  afford  only  an  intermitting  supply  This  is  especially  the  case,  as 
already  mentioned,  with  the  Nervous  system,  which  is  so  predominant  a  feature 


54  GENERAL    VIEW    OF    THE     HUMAN     FUNCTIONS. 

in  the  constitution  of  Man;  and  we  accordingly  find  both  objects  provided  for, 
in  the  formation  of  a  large  quantity  of  a  semi-organized  product,  which  contains 
within  itself  the  materials  of  all  the  tissues,  and  is  constantly  being  carried  into 
relation  with  them.  —  The  propulsion  of  the  Blood  through  the  large  trunks, 
which  subsequently  divide  into  capillary  vessels,  is  due  to  the  contractions  of  a 
hollow  muscular  organ,  the  Heart ;  but  these,  like  the  peristaltic  movements  of 
the  alimentary  canal,  are  quite  independent  of  the  agency  of  the  Nervous  system; 
and  are  therefore  to  be  referred  to  the  class  of  Organic  movements,  such  as  occur 
in  Vegetables.  The  rate  and  force  of  the  heart's  movements  are  greatly  influ- 
enced, however,  by  conditions  of  the  Nervous  system ;  and  these,  also,  by  calling 
into  play  the  contractility  of  the  walls  of  the  arteries,  exert  a  powerful  influence 
upon  their  calibre,  and  consequently  upon  the  distribution  of  blood  to  particular 
parts  and  organs,  as  we  see  in  the  acts  of  blushing  and  erection. 

33.  Upon  the  circulation  of  the  Blood  through  all  parts  of  the  fabric,  depends 
in  the  first  place  the  Nutrition  of  the  tissues.     Upon  this  subject,  formerly  in- 
volved in  the  greatest  obscurity,  much  light  has  recently  been  thrown  by  Micro- 
scopic   discovery;    it    being    now  understood   that  the    continued    growth    and 
renewal  of  each  tissue  is  effected  by  a  continuation   of  a  process  essentially 
similar  to  that  by  which  it  was  first  developed.     The  greatest  difficulty,  in  the 
present  condition  of  our  knowledge,  is  to  comprehend  the  reason  why  such  a 
variety  of  products  should  spring  up  in  the  first  instance,  when  the  cells  in  which 
they  all  originate  appear  to  be  so  exactly  alike.     The  important  discoveries  now 
referred  to  are  not  confined  to  healthy  structures;  for  it  has  been  ascertained  that 
diseased  growths  have  a  similar  origin  and  mode  of  extension;    and  that  the 
malignant  character  assigned  to  Schirrus,  Medullary  Sarcoma,  and  other  such 
productions,  is  partly  connected  with  the  fact,  that  they  are  composed  of  cells 
which  undergo  little  metamorphosis,  and  retain  their  reproductive  power;  so  that 
from  a  single  cell,  as  from  that  of  a  Vegetable  Fungus,  a  large  structure  may 
rapidly  spring  up,  the  removal  of  which  is  by  no  means  attended  with  any  cer 
tainty  that  it  will  not  speedily  reappear,  from  some  germs  left  in  the  system.— 
The  independent  vitality  of  the  cells  in  which  all  organized  tissues  originate, 
might  be  of  itself  a  satisfactory  proof,  that  in  Animals,  as  in  Plants,  the  actions 
of  Nutrition  are  effected  by  the  powers  with  which  they  are  individually  en- 
dowed; and  that,  whatever  influence  the  Nervous  system  may  have  upon  them, 
its  agency  is  not  essential  to  their  performance.     Moreover,  it  is  certain  that  no 
formation  of  nervous  matter  takes  place  in  the  embryonic  structure,  until  the 
processes  of  Organic  life  have  been  for  some  time  in  active  operation.     The  influ- 
ence which  the  Nervous  System  is  known  to  have  upon  the  function  of  Nutrition, 
is  probably  exerted  in  two  ways ;  first,  through  its  power  of  regulating  the  dia- 
meter of  the  arteries  and  capillaries,  by  which  it  controls  in  some  degree  the 
afflux  of  blood ;  and  secondly,  through  the  more  direct  relation  of  the  Nervous 
force  to  those  other  forms  of  Vital  agencyj  which  manifest  themselves  in  the 
growth,  development,  and  maintenance  of  the  living  tissues.     (See  PRINC.  OP 
GEN.  PHYS.) 

34.  The  continual  disintegration  to  which  the  living  tissues  are  subject,  from 
the  various  causes  already  referred  to,  renders  it  necessary  that  a  means  should  be 
provided  for  conveying  away  the  waste,  as  well  as  for  supplying  the  new  material. 
This  is  partly  effected  by  the  Venous  circulation ;  which  takes  up  a  large  part  of 
the  products  of  incipient  decomposition,  and  conveys  them  to  organs  of  Excretion , 
by  which  they  may  be  separated  and  cast  forth  from  the  body.    The  first  product 
of  the  decay  of  all  organized  structures,  is  carbonic  acid ;   and  this  is  the  one 
which  is  most  constantly  and  rapidly  accumulating  in  the  system,  and  the  reten- 
tion of  which,  therefore,  within  the  body,  is  the  most  injurious.      Accordingly  we 
find  a  most  important  organ  —  the  Pulmonary  apparatus  —  adapted   to  remove 
it;  and  to  this  the  whole  current  of  Venous  blood  passes,  before  it  is  again  sent 
through  the  system.     The  efficient  performance  of  this  function  of  Respiration 


FUNCTIONS  OF  VEGETATIVE  LIFE.  Sf» 

is  so  essential  to  the  well-being  of  warm-blooded  animals,  that  a  special  hi  .'art  is 
provided  for  propelling  the  blood  through  their  Lungs,  in  addition  to  the  one 
possessed  by  most  of  the  lower  animals,  the  function  of  which  is  the  propulsion 
of  the  blood  through  the  system.  In  these  organs,  the  blood  is  subjected  to  the 
influence  of  the  atmosphere,  whereby  the  carbonic  acid  with  which  it  was  charged, 
is  removed  and  replaced  by  oxygen  ;  and  this  change  takes  place  through  the 
delicate  membrane  that  lines  the  air-cells,  in  accordance  with  the  physical  law  of 
the  mutual  diffusion  of  gases.  But  the  introduction  of  Oxygen  into  the  blood, 
also,  is  necessary  for  the  maintenance  of  those  peculiar  vivifying  powers,  by  which 
the  Nervous  and  Muscular  systems  are  kept  in  a  state  fit  for  activity ;  and  its 
union  with  their  elements  appears  to  be  a  necessary  condition  of  the  manifestation 
of  their  peculiar  powers.  Of  this  union,  carbonic  acid  is  one  of  the  chief  pro- 
ducts ;  and  we  shall  find  that  the  demand  for  oxygen,  and  the  excretion  of  car- 
bonic acid,  vary  according  to  the  amount  of  Nervo-Muscular  action  put  forth. 
The  continual  formation  of  carbonic  acid,  in  this  arid  other  interstitial  changes, 
has  a  most  important  purpose  in  the  vital  economy,  that  of  keeping  up  its  tempe- 
rature to  a  fixed  standard;  for  the  union  of  carbon  and  oxygen  in  this  situatiom 
may  be  compared  to  a  process  of  slow  combustion,  and,  in  combination  with  other 
combustive  processes  (in  which  hydrogen,  sulphur,  phosphorus,  &c.,  undergo  oxi- 
dation), it  is  the  principal  means  of  sustaining  the  independent  heat  of  the  'warm- 
blooded' animal.  There  is  in  the  system  a  certain  self-adjusting  power,  whereby 
the  consumption  of  the  pabulum  provided  for  the  combustive  process  is  regulated 
according  to  the  external  temperature ;  so  that  whilst,  the  external  temperature 
being  the  same,  the  amount  of  carbonic  acid  excreted  varies  with  the  dogree  of 
muscular  exertion  made  by  the  individual,  any  depression  of  the  external  tempe- 
rature, requiring  an  augmented  production  of  heat,  occasions  an  incioased  com- 
bustion of  the  oxidizable  solids  of  the  body,  which  is  indicated  by  an  increase  in 
the  exhalation  of  carbonic  acid  from  the  lungs.  — The  interchange  of  oxygen  and 
carbonic  acid  between  the  atmosphere  and  the  blood,  can  only  be  kept  up  by  a 
continual  renewal  of  the  air  in  the  interior  of  the  lungs,  and  of  the  blood  in  their 
capillaries.  The  former  is  effected  by  a  set  of  muscular  movements  that  depend 
on  the  (  reflex'  power  of  certain  nervous  centres,  and  not  on  any  exertion  of  the 
will  of  the  individual.  It  is  not  even  requisite  that  he  should  be  conscious  of 
their  performance;  the  ordinary  power  of  the  stimulus  that  excites  the  movement, 
not  being  sufficient  to  cause  itself  to  be  felt/  unless  his  attention  be  specially 
directed  to  it.  But  if  the  respiratory  movements  be  suspended  for  a  short  time, 
sensations  of  distress  are  soon  experienced,  which  rapidly  augment  with  the  con- 
tinuance of  the  suspension ;  and  no  exertion  of  the  will  can  any  longer  prevent 
the  performance  of  the  movements  which  are  appropriate  to  relieve  them.  Thus 
we  see  that  these  movements,  although  placed  in  Man  under  the  control  of  the 
Will  to  such  an  extent  as  to  enable  him  to  regulate  them  in  the  actions  of  speech, 
are  in  themselves  quite  as  independent  of  that  will,  as  are  those  of  the  Heart, 
whose  automatic  power  has  been  already  alluded  to. 

35.  The  function  of  the  Liver  as  an  excreting  organ  is,  like  that  of  the  lungs, 
two-fold  :  it  separates  from,  the  blood  a  large  quantity  of  the  superfluous  IryJro- 
carbon,  which  it  acquires  in  circulating  through  the  tissues;  and  it  combines  this 
with  other  elements,  into  a  secretion  which  is  of  great  importance  in  the  digestive 
process.  The  hepatic  circulation,  however,  is  not  kept  up  by  a  distinct  impelling 
organ;  but  the  venous  blood  from  the  abdominal  viscera  (and  in  the  lower  Ver- 
tebrata,  that  from  the  posterior  part  of  the  body)  passes  through  the  liver  on  its 
return  to  the  heart.  —  But  further,  all  animal  substauces  have  a  tendency,  during 
their  decomposition,  to  throw  off  nitrogen,  as  well  as  carbon;  and  this  nitrogen, 
in  combination  with  other  elements,  forms  those  peculiar  azotized  compounds, 
which  it  is  the  special  function  of  the  Kidney  to  eliminate  from  the  circulating 
fluid.  The  most  characteristic  of  these  in  Man,  namely  urea,  contains  a  larger 
proportion  of  nitrogen  thau  is  found  in  any  other  organic  compound  ;  and  it* 


56  GENERAL     VIEW     OF     THE     HUMAN     FUNCTIONS. 

identical  in  its  chemical  nature  with  cyanafe  of  ammonia.  Its  production  seems 
in  great  part  to  depend  upon  the  disintegration  of  the  Muscular  tissue;  but  there 
is  also  evidence  that  it  may  result  from  the  retrograde  metamorphosis  of  Albumi- 
nous or  even  of  Gelatinous  matters  circulating  in  the  blood.  The  action  of  the 
Kidneys,  which  also  serve  as  emunctories  for  various  soluble  matters  (especially 
saline  compounds)  whose  accumulation  in  the  blood  would  be  injurious,  is  equally 
essential  to  the  continued  performance  of  the  other  vital  functions,  with  that  of 
the  lungs  and  liver  5  since  death  invariably  follows  its  suspension,  unless  some 
other  means  be  provided  by  Nature  (as  occasionally  happens),  for  the  separation 
of  its  characteristic  excretion  from  the  circulating  blood. — But  further,  the  regu- 
lation of  the  amount  of  fluid  in  the  vessels  is  provided  in  a  kind  of  safety-valve 
structure,  existing  in  the  Kidneys,  which  readily  permits  the  escape  of  aqueous 
fluid  from  the  capillary  vessels,  into  the  urinar}T  canals,  by  a  process  of  physical 
transudation,  which  is  altogether  distinct  from  the  secretion  of  that  solid  matter, 
which  it  is  the  office  of  the  kidneys  to  separate  from  the  circulating  blood. 
Hence,  if  the  excretion  of  fluid  from  the  skin  be  checked  by  cold,  so  that  an 
accumulation  would  take  place  in  the  vessels,  the  increased  pressure  within  them 
causes  an  increased  escape  of  water  through  the  kidneys. 

86.  The  various  Secretions  which  have  not  already  been  adverted  to,  appear 
for  the  most  part  to  have  for  their  object  the  performance  of  some  special  func- 
tion in  the  system,  rather  than  the  conveyance  out  of  it  of  any  substances  which 
it  would  be  injurious  to  retain.  This  is  the  case,  for  example,  in  regard  to  the 
secretion  of  the  Lachrymal,  Salivary,  and  Mammary  Glands,  as  well  as  with  that 
of  the  Mucous  and  Serous  Membranes.  The  excretion  of  fluid  from  the  Cuta- 
neous surface,  however,  appears  to  answer  two  important  purposes,  —  the  removal 
from  the  body  of  a  portion  of  its  superfluous  fluid,  containing  products  of  decom- 
position,—  and  the  regulation  of  its  temperature.  Just  as,  by  the  action  of  the 
Lungs,  the  conditions  are  supplied,  by  which  the  temperature  of  the  body  is  kept 
up  to  a  certain  standard,  so,  by  that  of  the  Skin,  this  is  prevented  from  rising  too 
high ;  for  by  the  continual  exudation  from  its  surface  of  fluid  which  has  to  be 
carried  off  by  evaporation,  a  degree  of  cold  is  generated,  which  keeps  the  calorific 
processes  in  check ;  and  this  exudation  is  augmented  in  proportion  to  the  eleva- 
tion of  the  external  temperature,  which  seems,  in  fact,  the  direct  stimulus  to  the 
process.  —  In  all  forms  of  true  Secretion,  the  selection  of  the  materials  to  be  sepa- 
rated from  the  blood,  is  accomplished,  like  selective  Absorption,  by  the  agency 
of  cells.  These  are  developed  in  the  interior  of  the  secreting  organ ;  and  when 
they  are  distended  with  the  fluid  they  have  imbibed,  they  either  allow  it  to  escape 
by  transudatiou,  or,  their  term  of  life  having  expired,  they  burst  or  liquefy,  dis- 
charging their  contents  into  the  ducts,  by  which  the  product  thus  secreted  is  con- 
veyed away.  In  the  case  of  Adipose  tissue,  we  have  an  instance  in  which  the 
secreted  product  (separated  from  the  blood  by  the  cells  of  which  this  tissue  essen- 
tially consists)  is  not  carried  out  of  the  body,  but  remains  to  form  a  constituent 
part  of  it. 

37.  There  is  no  sufficient  reason  to  believe,  that  the  Nervous  System  has  any 
more  direct  influence  on  the  process  of  Secretion,  than  it  has  been  stated  to  have 
on  that  of  Nutrition.  That  each  glandular  organ  has  an  independent  action  of 
its  own,  in  virtue  of  the  endowments  of  its  component  cells,  can  scarcely  now  be; 
doubted.  Still,  daily  experience  teaches  that  almost  every  secretion  in  the  body  is; 
affected  by  states  of  Mind,  which  must  operate  through  the  nerves;  and  while 
this  may  be  fairly  accounted  for  in  part  by  the  remarkable  influence  which  the 
Nervous  system  possesses  over  the  Circulation,  it  must  also  be  in  part  attributed  to 
the  special  agency  of  the  Nervous  force  upon  the  chemical  or  vital  process  of 
Secretion  itself.  The  flow  of  the  secreted  fluids  through  their  efferent  ducts 
seems  t'o  be  principally  caused  by  the  proper  contractility  of  these,  which  (like 
that  of  the  heart  and  alimentary  canal)  is  directly  stimulated  by  the  contact  of 
their  contents;  but  there  is  also  evidence  that  this  contractility  may  be  affected 


FUNCTIONS     OF    VEGETATIVE     LIFE.  57 

(as  it  is  in  those  two  instances)  by  the  nervous  system.  Whore,  as  happens  in 
the  case  of  the  urinary  excretion,  there  is  a  reservoir  into  which  it  is  received  as 
fast  as  it  is  formed,  for  the  purpose  of  preventing  the  inconvenience  which  its 
constant  passage  from  the  body  would  otherwise  occasion,  the  power  of  emptying 
this  reservoir  is  usually  placed  in  some  degree  under  the  dominion  of  the  will, 
although  chiefly  governed  by  reflex  action.  It  is  obvious  that  such  a  provision  is 
by  no  means  essential  to  the  function ;  and  that  it  has  for  its  object  the  adapta- 
tion, merely,  of  that  function  to  the  conditions  of  Animal  existence. 

38.  Thus  we  see  that  when  we  enter,  as  it  were,  into  the  penetralia  of  the 
Animal  system,  and  study  those  processes  in  which  the  development  and  mainte- 
nance of  the  material  fabric  essentially  consist,  we  find  them   performed  under 
conditions  essentially  the  same  as  those  which  obtain  in  Plants;  and  we  observe 
that  the  operations  of  the  Nervous  System  have  none  but  an  indirect  influence 
or  control  over  them.     It  is,  therefore,  quite  philosophical  to  distinguish  these 
Organic  Functions,  or  phenomena  of  Vegetative  Life,  from  those  concerned  in 
the  Life  of  Relation,  or  Animal  Life.     The  distinction  is,  indeed,  of  great  prac- 
tical importance,  and  lies  at  the  foundation  of  all  Physiological  Science ;  yet  it  is 
seldom  accurately  made,  and  very  confused  notions  on  the  subject  are  generally 
prevalent.1 

39.  The  process  of  Generation,  like  that  of  Nutrition,  has  been  until  recently 
involved  in  great  obscurity;  and  although  it  cannot  be  said  to  be  yet  fully  eluci- 
dated, it  has  been  brought,  by  late  investigations,  far  more  within  our  compre- 
hension, than  was  formerly  deemed  possible.     The  close  connection  between  the 
Reproductive  and  Nutritive  operations,  both  as  regards  their  respective  charac- 
ters, and  their  d  pendence  upon  one  another,  has  long  been  recognized;  and  it  is 
now  rendered  still  more  evident.     Nutrition  has  not  unaptly  been  designated,  "a 
perpetual  reproduction  ;"   and  the  expression  is  strictly  correct.     In  the  fully- 
formed  organism,  the  supply  of  alimentary  material  to  every  part  of  the  fabric 
enables  it  to  produce  a  tissue  resembling  itself;  thus  we  ordinarily  find  true  bone 
produced  only  in  continuity  with  bone,  nerve  with  nerve,  muscle  with  muscle, 
and  so  on.      Hence  it  would  appear  that,  when  a  portion  of  tissue  has  once  taken 
on  a  particular  kind  of  action,  it  continues  to  reproduce  itself  on  the  same  plan. 
But  in  the  proper  Generative  process  it  is  different.     A  single  cell  is  generated 
by  certain  preliminary  actions,  from  which  cell  all  those  which  subsequently  com- 
pose the  embryonic  structures  take  their  origin;  and  it  is  not  until  a  later  period 
that  any  distinction  of  parts  can  be  traced,  in  the  mass  of  vesicles  which  spring 
from  it.     This  distinction  becomes  more  and  more  obvious  as  development  ad- 
vances ;  the  form  and  position  of  the  principal  organs  being  first  marked  out  by 
peculiar  aggregations  of  cells ;  and  the  intimate  structure  of  each  being  brought, 
by  progressive  metamorphosis  of  the  tissues  consecutively  developed  from  these, 
to  the  type  which  is  characteristic  of  it.  —  Hence  we  may  state  the  essential 
character  of  the  function  of  Generation  to  consist  in  the  production  of  a  cell  of 
most  peculiar  endowments;  which,  when  supplied  with  nutriment,  and  acted  on 
by  warmth,  does  not  simply  multiply  itself  so  as  to  produce  a  mere  aggregation 
of  similar  cells,  but  gives  origin  to  a  succession  of  broods,  which  undergo  such 
heterogeneous  transformations,  as  ultimately  to  evolve  an  organism  capable  of 
maintaining  an  independent  existence,  in  which  the  number  of  different  parts  is 
equal  to  that  of  the  functions  to  be  performed,  each  separate  part  having  an  oflice 
distinct  from  that  of  the  rest,,  and  being  specially  adapted  to  it  alone. 

40.  But,  it  will  be  inquired,  how  and  where  in  the  Human  body  (and  in  the 

1  It  has  been  often  said,  for  example,  that  the  function  of  Respiration  is  the  connecting 
link  between  the  two :  the  fact  being,  however,  that  the  true  process  of  Respiration  is  no 
more  a  function  of  Animal  life,  than  is  any  ordinary  process  of  secretion:  but  that,  in 
order  to  secure  the  constant  interchange  of  air,  which  is  necessary  to  its  performance,  the 
assistance  of  the  nervous  and  muscular  systems  is  called  in,  though  not  in  a  manner  which 
necessarily  involves  either  consciousness  or  will. 


58  GENERAL     VIEW     OF    THE     HUMAN     FUNCTIONS. 

higher  Animals  in  general)  is  this  embryonic  vesicle  produced;  and  what  are  the 
relative  offices  of  the  two  sexes  in  its  formation  ?  This  is  a  question  which  must 
still  be  answered  with  some  degree  of  doubt ;  and  yet  observed  phenomena,  if 
explained  by  the  aid  of  analogy,  seem  to  lead  to  a  very  direct  conclusion.  The 
embryonic  vesicle  itself,  like  other  cells,  must  arise  from  a  germ  ;  and  reasons 
will  be  hereafter  given  for  the  belief,  that  this  germ  is  the  product  of  the  admix- 
ture of  the  contents  of  the  '  sperm  cell'  of  the  male  with  that  of  the  '  germ  cell' 
of  the  female ;  and  that  this  admixture  is  requisite  for  the  regeneration  of  that 
1  germinal  capacity/  which  is  gradually  expended  in  the  developmental  process. 
The  operation  immediately  concerned  in  this  function,  as  in  that  of  Nutrition, — 
namely,  the  preparation  of  the  '  sperm  cells'  and  of  the  'germ  cells,'  the  act  of 
fecundation,  and  the  development  of  the  embryo,  —  are  not  dependent  upon  ner- 
vous agency,  and  are  but  little  influenced  by  it;  and  the  functions  of  Animal 
Life  are  called  into  play  only  in  the  preliminary  and  concluding  steps  of  the  pro- 
cess. In  many  of  the  lower  Animals,  there  is  no  sexual  congress,  even  where 
the  concurrent  action  of  two  sets  of  organs,  belonging  to  two  separate  individuals, 
a  necessary  for  the  process;  for  the  ova  are  liberated  by  one,  and  the  spermato- 
zoa by  the  other,  and  the  accidental  meeting  of  the  two  produces  the  required 
/esult.  In  many  Animals  higher  in  the  scale,  the  impulse  which  brings  the  sexes 
together  is  of  a  purely  instinctive  kind.  But  in  Man,  it  is  of  a  very  compound 
nature.  The  instinctive  propensity,  unless  unduly  strong,  is  controlled  and  guided 
by  the  Will;  and  serves  (like  the  feelings  of  hunger  and  thirst)  as  a  stimulus  to 
tfie  reasoning  processes,  by  which  the  means  of  gratifying  it  are  obtained ;  while 
i  moral  sentiment  or  affection  of  a  much  higher  kind  is  closely  connected  with  it, 
which  acts  as  an  additional  incitement.  Those  movements,  however,  which  are 
most  closely  connected  with  the  essential  part  of  the  process,  are,  like  those  of 
deglutition,  respiration,  &c.,  simply  reflex  and  involuntary  in  their  character; 
and  thus  we  have  another  proof  of  the  constancy  of  the  principle,  that,  where  the 
action  of  the  apparatus  of  Animal  Life  is  brought  into  near  connection  with  the 
Organic  functions,  it  is  not  such  as  requires  the  operation  of  the  purely  animal 
powers, — sensation  and  volition. 

41.  Thus,  then,  as  it  has  been  lucidly  remarked,  it  may  be  affirmed,  as  most 
consistent  with  our  present  knowledge,  "  that  the  whole  Organic  life  of  Animals, 
—  i.  e.,  everything  which  goes  on  in  them  without  the  intervention  of  any  sensa- 
tion or  other  mental  act,  —  may  go  on  without  the  intervention  of  the  Nervous 
System,  and  stands  in  no  relation  of  dependence  to  any  changes  in  nervous  mat- 
ter; just  as  the  corresponding  functions  of  circulation,  nutrition,  secretion,  absorp- 
tion, go  on  in  equal  perfection   in   the  lowest  class  of  animals  among  which  no 
nerves  are  detected,  and  in  the  whole  vegetable  kingdom  in  which  there  is  no 
plausible  reason  for  supposing  that  nerves  exist :  and  that  the  Nervous  System 
lives  and  grows  within  an  Animal,  as  a  parasitic  Plant  does  in  a  Vegetable ;  with 
its  life  anol  growth,  certain  sensations  and  mental  acts,  varying  in  the  different 
classes  of  Animals,  are  connected  by  nature  in  a  manner  altogether  inscrutable 
to  man;  but  the  objects  of  the  existence  of  Animals  require,  that  these  mental 
acts  should  exert  a  powerful  controlling  influence  over  all  the  textures  and  organs 
of  which  they  are  composed."  ! 

3.  Functions  of  Animal  Life. 

42.  The  existence  of  consciousness,  by  which  the  individual  (le  moi,  in  the 
language  of  French  physiologists)  becomes  sensible  of  impressions  made  upon  its 
bodily  structure,  —  and  the  power  of  spontaneously  exciting  contractions  in  its 
tissues,  by  which  evident  motions   are  produced,  —  are   to  be  regarded   as  the 
characteristic  attributes  of  the  beings  composing  the  Animal  Kingdom  ;  although 

See  "Brit,  and  For.  Med.  Eev.,"  vol.  iii.  (1887),  pp.  9,  10.— The  whole  of  the  masterly 
from  "which  the  above  extract  is  taken,  is  well  deserving  of  perusal. 


FUNCTIONS     OF    ANIMAL     LIFE.  59 

their  possession  by  many  of  the  tribes  which  seem  to  have  their  appropriate  place 
in  that  kingdom,  is,  to  say  the  least,  extremely  doubtful.1  Of  the  movements 
exhibited  by  Animals,  there  are  many  which  are  no  more  to  be  regarded  as  indi- 
cations of  consciousness,  than  are  those  executed  by  certain  plants  ;  being  simply 
the  expressions  or  manifestations  of  a  peculiar  kind  of  vital  force  in  the  tissues 
by  whose  instrumentality  they  are  performed.  Such  movements,  in  beings  of 
lowest  organisation,  probably  bear  a  much  greater  proportion  to  the  whole  amount 
of  those  exhibited  by  them,  than  they  do  in  the  higher;  whilst  those  which  we 
may  regard  as  specially  dependent  on  a  nervous  system,  appear  to  constitute  but 
a  small  part  of  their  general  vital  actions.  The  life  of  such  beings,  therefore, 
bears  a  much  closer  resemblance  to  that  of  the  Vegetable,  than  to  that  of  the 
higher  Animal.  Their  organic  functions  are  performed  with  scarcely  more  of 
sensible  movement  than  is  seen  in  plants ;  and  of  the  motions  which  they  do 
exhibit  (nearly  all  of 'them  immediately  concerned  in  the  maintenance  of  the 
organic  functions),  it  is  probable  that  many  are  the  result  of  the  simple  contrac- 
tility of  their  tissues,  called  into  action  by  the  stimuli  directly  applied  to  them. 
It  is  scarcely  possible  to  imagine  that  such  beings  can  enjoy  any  of  those  higher 
mental  powers,  which  Man  recognizes  by  observation  on  himself,  and  of  which 
he  discerns  the  manifestations  in  those  tribes,  which,  from  their  nearer  relation  to 
himself,  he  regards  as  more  elevated  in  the  scale  of  existence.  —  If  we  direct  our 
attention,  on  the  other  hand,  to  the  psychical2  operations  of  Man,  as  forming  part 
of  his  general  vital  actions,  we  perceive  that  the  proportion  is  completely  reversed. 
So  far  from  his  Organic  life  exhibiting  a  predominance,  it  appears  entirely  subor- 
dinate to  his  Animal  functions,  and  seems  destined  only  to  afford  the  conditions 
for  their  performance.  If  we  could  imagine  his  nervo-nmscular  apparatus  to  be 
isolated  from  the  remainder  of  his  corporeal  structure,  and  to  be  endowed  in  itself 
with  the  power  of  maintaining  its  integrity,  we  should  have  all  that  is  essential 
to  our  idea  of  Man.  But,  as  at  present  constituted,  this  apparatus  is  dependent, 
for  the  conditions  of  its  functional  activity,  upon  the  nutritive  apparatus ;  and  the 
whole  object  of  the  latter  appears  to  be  the  supply  of  those  conditions.  That  his 
mental  activity  should  be  thus  made  dependent  upon  the  due  supply  of  his  bodily 
wants,  is  a  part  of  the  general  scheme  of  his  probationary  existence;  and  the  first 
excitement  of  his  intellectual  powers  in  a  great  degree  results  from  the  demand 
thus  set  up  for  alimentary  material. 

43.  The  ministration  of  the  Nervous  System  to  purely  Animal  life,  obviously 
consists  in  part  in  rendering  the  mind  cognizant  of  that  which  is  taking  place 
around,  and  in  enabling  it  to  act  upon  the  material  world,  by  the  instruments  with 
which  the  body  is  provided  for  the  purpose.  It  is  important  to  observe,  that 
every  method  at  present  certainly  known,  by  which  Mind  can  communicate  with 
Mind,  involves,  in  the  first  place,  a  generation  of  nervous  force,  which  excites 
muscular  contraction;  secondly,  a  physical  change  determined  by  that  contraction, 
the  medium  of  which  may  be  sound,  light,  e>r  motion ;  and  thirdly,  the  operation 
of  this  physical  change  as  an  l  impression'  upon  the  sensory  nerves,  and  through 
them  upon  the  sensorial  ganglia,  of  the  other  party.  Such  is  the  case,  for  exam- 
ple, not  only  in  that  communication  which  takes  place  by  language,  whether  writ- 
ten or  spoken ;  but  in  the  look,  the  touch,  the  gesture,  which  are  so  frequently 
more  expressive  than  any  words  can  be :  and  thus  we  see  that  our  interchange  of 
ideas  and  emotions  which  are  most  purely  psychical  in  their  nature,  can  only  be 
accomplished  through  the  intermediation  of  physical  forces.  That  imperfections 
in  such  communication  are  thus  involved  in  the  very  nature  of  our  present  condi- 
tion, and  that  all  the  higher  operations  of  the  mind  are  trammelled  and  restricted 
by  the  limited  powers  of  its  corporeal  instrument,  is  a  matter  of  constant  and  indu- 

1  See  "  Principles  of  Comparative  Physiology,"  Chap.  XIII. — Am.  Ed. 

*  Here  and  elsewhere  this  term  will  be  employed  in  its  most  extended  sense,  to  designate 
all  the  mental  operations, — whether  intellectual,  emotional,  or  instinctive,  —  of  which 
Man's  nervous  system  is  the  instrument. 


60  GENERAL    VIEW    OF    THE     HUMAN    FUNCTIONS. 

bitable  experience.  On  the  other  hand,  that,  in  a  future  state  of  being,  the  com- 
munion  of  mind  with  mind  will  be  more  intimate,  and  that  Man  will  be  admitted 
into  more  immediate  converse  with  the  Supreme  Intelligence,  appears  to  be  alike 
the  teaching  of  the  most  comprehensive  Philosophical  inquiries,  and  of  the  most 
direct  Revelation  of  the  Divinity. 

44.  The  Organs  of  Sense  are  instruments,  which  are  adapted  to  enable  particu- 
lar nerves  to  receive  impressions  from  without,  of  a  kind,  and  in  a  degree,  of 
which  they  would  not  otherwise  be  sensible.  Thus,  although  the  simple  mecha- 
nical impression  produced  by  contact  of  a  hard  body,  produces  such  a  change  in 
it,  as,  being  propagated  to  the  central  sensorium,  excites  sensation  there,  it  is 
evident  that  a  nerve  must  be  peculiarly  modified  at  its  peripheral  expansion  to 
receive  its  impressions  from  the  undulations  of  the  air;  still  more,  to  be  suscepti- 
ble of  the  impressions  produced  by  those  undulations  to  which  most  Natural  Phi- 
losophers now  attribute  the  transmission  of  light.  And,  even  when  this  has  been 
provided  for,  by  some  modification  in  the  structure  or  arrangements  of  the  nerve 
fibres  themselves,  or  of  the  vesicular  matter  in  connection  with  them,  a  further 
provision  is  still  required  for  giving  to  the  mind  a  distinct  consciousness  of  exter- 
nal objects  in  all  their  variety  of  shapes,  colours,  lights  and  shadows,  &c. ;  or  for 
enabling  it  to  form  ideas  of  the  direction,  pitch,  quality,  &c.,  of  sonorous  undula- 
tions There  is  reason  to  believe  that  many  among  the  lower  Animals,  which 
cannot  see  objects  around  them,  are  conscious  of  the  influence  of  light;  and  thus 
the  distinction  between  the  mere  reception  of  the  impression,  and  the  excitement 
of  a  visual  perception,  becomes  evident.  The  former  may  take  place  through  the 
intervention  of  nerves,  whose  sensory  extremities  offer  no  extraordinary  peculiar- 
ities :  the  latter  can  only  be  received  through  the  medium  of  an  instrument,  which 
shall,  from  the  mixture  of  rays  falling  equally  upon  every  part  of  its  surface,  pro- 
duce an  optical  image,  and  then  impress  it  upon  the  expanded  surface  of  the 
nerve;  so  that,  each  fibril  receiving  a  distinct  impression,  the  mind  may  form  its 
picture  by  the  combination  of  the  whole.  —  That  this  is,  in  fact,  the  share  which 
the  organs  of  Special  Sense  bear  in  the  general  endowments  of  the  whole  appa- 
ratus, may  be  inferred  especially  from  the  conformation  of  the  Eye  ;  which  is  in 
every  respect  a  merely  optical  instrument,  of  the  greatest  beauty  and  perfection, 
adapted  to  form  upon  the  retina,  in  the  most  advantageous  manner,  the  images 
of  surrounding  objects  in  all  their  variations.  —  There  can  be  little  doubt,  that 
the  structure  of  the  Ear  is  arranged  to  do  the  same  for  the  sonorous  vibrations, 
which  the  eye  does  for  the  rays  of  light ;  that  is,  through  its  means,  the  undula- 
tions which  strike  upon  the  external  surface  of  the  organ  are  separated  and  dis- 
tinguished, those  of  a  like  kind  being  brought  together  upon  one  division  of  the 
nerve,  and  those  of  another  order  upon  a  different  set  of  fibres ;  so  that  the  dif- 
ferent kinds  of  sound,  and  the  peculiar  quality  and  direction  of  each,  may  be  dis- 
criminated ;  whilst,  by  the  concentration  of  all  the  impressions  of  the  same  charac- 
ter, a  higher  amount  offeree  is  given  to  them. — The  apparatus  which  ministers, 
however,  to  the  sense  of  Smell,  is  far  less  complete  in  its  endowments ;  for  it 
serves  only,  in  Man  at  least,  for  the  discrimination  of  odorous  emanations,  and 
affords  no  guidance  with  regard  either  to  their  direction  or  their  source.  In  fact, 
the  kind  of  information  which  Man  receives  through  this  sense,  seems  very  much 
akin  to  that  which  the  lowest  animals  possessing  visual  organs  can  derive  from 
their  employment.  Still  a  special  organ  of  sense  is  required,  to  enable  the  olfac- 
tive  nerve  to  be  impressed  by  the  peculiar  agency  of  odorous  emanations;  which, 
whatever  be  their  nature,  have  no  operation  upon  ordinary  sensory  surfaces.  — 
It  is  not  a  little  remarkable,  that  the  speciality  of  organization  of  the  nerves  of 
Sight,  Hearing,  and  Smell,  renders  them  incapable  of  receiving  ordinary  mecha- 
nical impressions;  so  that  the  contact  of  solid  substances  with  the  sensory  sur- 
faces which  they  supply,  is  not  felt,  except  through  the  instrumentality  of  other 
nerves ;  and  no  irritation  of  their  trunks,  mechanical  or  otherwise,  gives  rise  to 
feelings  of  pain.  The  sense  of  Taste,  however,  though  special  in  regard  to  the 


FUNCTIONS    OF   ANIMAL    LIFE.  Cl 

peculiarity  of  the  impressions  which  its  organ  is  adapted  to  receive,  is  closely  akin 
to  that  of  Touch  in  the  conditions  under  which  it  is  exercised ;  the  absolute  contact 
of  the  sapid  substance  with  the  sensory  surface  being:  requisite ;  and  the  papillary 
organs  in  which  the  gustative  nerves  may  be  said  to  originate,  being  essentially 
the  same  in  structure  with  those  of  ordinary  tactile  surfaces. 

45.  The  Brain  and  Spinal  Cord  of  Man,  in  which  by  far  the  greater  part  of 
the  afferent  nerves  terminate,  and  from  which  nearly  all  the  motor  nerves  arise, 
may  be  considered  as  made  up  of  an  aggregation  of  a  number  of  distinct  gan- 
glionic  centres,  each  of  which  has  its  peculiar  endowments,  and  is  connected  with 
nervous  trunks  of  its  own.  —  Commencing  with  the  Spinal  Cord,  we  find,  on 
comparing  it  with  the  gangliated  column  of  Articulated  animals,  that  it  really 
consists  of  a  series  of  ganglia  disposed  in  a  longitudinal  line,  which  have  coa- 
lesced with  each  other ;  each  ganglion  being  the  centre  of  the  '  nervous  circle ' 
proper  to  one  vertebral  segment  of  the  trunk.  Throughout  the  entire  series  we 
find  no  other  endowment  than  that  of  reacting  upon  an  excitant;  this  excitant 
being  either  conveyed  by  the  afferent  nerve-trunks,  or  transmitted  downwards 
from  the  higher  parts  of  the  nervous  system.  No  impression  which  is  limited  to 
this  series  of  ganglia  excites  any  sensorial  change;  so  that  we  may  consider  the 
Spinal  Cord  as  the  special  instrument  of  the  '  exci to- motor '  division  of  the  func- 
tions of  the  nervous  system.  The  ordinary  Spinal  nerves  are  distributed  to  the 
sensory  surfaces  and  to  the  muscular  apparatus  of  the  body  generally ;  but  at  the 
summit  of  the  Cord  we  find  a  peculiar  set  of  ganglionic  centres,  included  in  that 
part  which  is  distinguished  as  the  M<dulla  Oblonaata,  whose  nerves  are  distri- 
buted to  the  organs  of  Respiration,  Deglutition,  &c.,  and  whose  function  consists 
in  sustaining  the  muscular  movements,  whose  performance  is  essential  to  the  con- 
tinuance of  these  functions.  The  movements  in  question  are  purely  reflex;  and 
there  is  no  other  reason  for  distinguishing  the  endowments  of  the  Medulla  Ob- 
longata  from  those  of  the  Spinal  Cord,  save  that  which  arises  out  of  the  speciality 
of  the  purposes  to  which  the  movements  are  subservient. — At  the  summit  of  the 
Spinal  Cord,  and  partly  lodged  in  the  substance  of  the  Medulla  Oblongata,  we 
find  the  series  of  Sensory  Ganglia,  which  may  in  their  totality  be  considered  as 
making  up  the  Sensorium.  This  includes  the  centres  to  which  proceed  the 
nerves  of  '  special  sense;'  arid  we  may  probably  rank  with  it  a  pair  of  ganglionic 
masses  (the  '  thalami  optici '),  towards  which  certain  afferent  fibres  of  the  spinal 
trunks  appear  traceable,  that  do  not  find  their  ganglionic  centres  in  the  spinal 
ganglia,  but  seem  to  pass  upwards  to  the  sensorium,  that  they  may  there  excite 
sensational  changes  of  the  '  common '  or  tactile  kind.  From  these  Sensory  Gan- 
glia we  do  not  find  any  motor  trunks  ostensibly  originating;  but  fibres  pass 
downwards  from  them  into  the  Spinal  cord,  which  either  directly  enter  its  efferent 
nerve-trunks,  or  which  serve  to  excite  to  action  the  ganglia  from  which  those 
trunks  arise ;  so  that  '  reflex '  actions  are  performed  by  the  instrumentality  of  the 
sensorial  ganglia,  which,  however,  differ  from  those  of  the  spinal  cord,  in  requiring 
Sensation  as  a  necessary  link  in  the  series  of  changes.  The  Sensory  ganglia  are, 
therefore,  the  centres  of  the  consensual  or  sensori-motor  actions.  —  This  series  of 
ganglionic  centres  corresponds  with  that  which  constitutes  the  principal  part  of 
the  Nervous  system  of  Insects;  and  its  operations,  when  not  interfered  with 
by  the  Cerebrum,  seem  to  be,  like  most  of  the  actions  of  Insects,  entirely  ' auto- 
matic '  or  instinctive.  Their  independent  agency  appears  to  be  the  source,  not 
merely  of  all  those  movements  which  are  originally  instinctive,  but  of  many  others 
which  come  by  habit  to  be  performed  involuntarily,  when  the  attention  is  other 
wise  engaged ;  these  have  been  termed  '  secondarily  automatic/ 

46.  But  in  Man,  as  in  all  other  animals  possessed  of  Intelligence,  by  which 
the  Will  is  animated  and  directed,  we  find  a  superadded  organ,  the  Cerebrum , 
which  is  not  itself  the  centre  of  either  sensory  or  motor  nerves,  but  which  derives 
from  the  sensori-motor  apparatus  just  described  all  its  stimulus  to  action,  and 
employs  it  as  its  instrument  of  operation  on  the  muscular  system.  The  functions 
of  this  organ,  which  are  purely  psychical,  are  first  excited  by  the  sensations  called 


G*2  GENERAL    VIEW    OF    THE    HUMAN    FUNCTIONS. 

forth  in  the  Sensory  ganglia,  which,  being  conveyed  to  the  Cerebrum,  give  rise, 
through  its  instrumentality,  to  Ideas;  and  these,  through  the  same  instrumental- 
ity, may  become  the  subject  of  Reasoning  processes.  But  ideas,  with  which  the 
feelings  of  pleasure  or  pain,  or  other  forms  of  emotional  sensibility,  are  associ- 
ated, constitute  Emotions ;  and  these,  if  strongly  excited,  may  act  downwards 
upon  the  muscles,  through  the  medium  of  the  automatic  apparatus,  quite  inde- 
pendently of  the  Will,  and  even  in  opposition  to  it.  And  there  are  certain 
peculiar  states  of  the  mind,  in  which,  the  power  of  the  Will  being  more  or  less 
completely  suspended,  Ideas  alone,  if  present  to  the  consciousness  in  sufficient 
intensity,  seem  capable  of  exciting  movements;  and  this  is  equally  the  case, 
whether  these  *  dominant  ideas'  have  directly  originated  in  external  sensations, 
or  whether  they  have  been  evolved  in  consequence  of  the  suggestive  action  of 
other  ideas.  Thus  the  Cerebral  ganglia  become  the  instruments  of  two  kinds  of 
action  upon  the  muscular  system,  which  may  be  considered  essentially  '  reflex/ 
as  being  executed  in  respondence  to  external  impressions,  without  any  volitional  or 
purposive  direction :  these  impressions  either  acting  simply  through  ideas,  and  thus 
producing  ideo-motor  actions,  or  through  ideas  with  which  feelings  are  associated, 
and  thus  producing  emotional  movements. — But  Ideas  are  not  merely  excited  by 
the  direct  stimulus  of  sensations;  they  may  be  called  up  by  previous  ideas,  with 
which  they  have  some  kind  of  association;  and  thus  ' trains  of  thought'  are 
suggestively  evolved,  by  an  operation  which,  as  will  be  shown  hereafter,  is  not 
less  truly  a  *  reflex  action'  of  the  Cerebrum,  than  is  that  which  manifests  itself 
directly  in  producing  movement.  These  trains  of  thought,  whether  imaginative 
or  ratiocinative,  may  proceed  quite  automatically,  if  left  entirely  without  control; 
but  the  Will  has  a  remarkably  power  of  directing  them,  by  concentrating  the 
attention  on  any  subject  which  it  may  choose  to  select  from  those  actually  present 
to  the  consciousness,  and  by  keeping  all  others  out  of  view.  And  when  the  con- 
flusion  of  the  Intellectual  process  has  been  thus  arrived  at,  the  Will  can  bring 
its  decision  to  bear  upon  the  muscular  system  ;  not,  however,  as  is  commonly 
supposed,  by  directly  transmitting  nerve-force  to  the  muscles  whose  action  will  be 
required,  but,  as  will  be  shown  hereafter,  by  impressing  its  determinations  on  the 
sensori-motor  portion  of  the  Nervous  system,  by  whose  instrumentality  the  requi- 
site movements  are  instinctively  prompted.1 

47.  Another  division  of  the  Nervous  System  appears  to  have  for  its  object,  to 
combine  and  harmonise  certain  muscular  movements  immediately  connected  with 
the  maintenance  of  Organic  life ;  and  to  bring  these  into  relation  with  certain 
conditions  of  the  mind.  There  is  further  reason  to  believe  that  it  also  influences, 
and  brings  into  connection  with  each  other,  the  processes  of  Nutrition,  Secretion, 
&c. ;  though  these,  like  the  muscular  movements  just  mentioned,  are  essentially 
independent  of  it.  —  This  portion  of  the  nervous  apparatus  is  commonly  known 
under  the  name  of  the  Sympathetic  system  ;  it  has  a  set  of  ganglionic  centres 
and  nerves  of  its  own ;  but  it  is  also  intimately  blended  with  the  Cerebro-spinal 
system,  both  receiving  fibres  from  it,  and  also  sending  fibres  into  it. 

1  With  reference  to  that  class  of  operations  of  which  the  Cerebrum  is  the  instrument,  it 
is  well  here  to  explain  that,  though  the  Physiologist  speaks  of  the  Intellectual  powers, 
Moral  feelings.  &c.,  as  functions  of  the  Nervous  System,  they  are  not  so  in  the  sense  in 
which  the  term  is  employed  in  regard  to  other  operations  of  the  bodily  frame.  In  general, 
by  the  function  of  an  organ,  we  understand  some  change  which  may  be  made  evident  to 
the  senses,  as  well  in  our  own  system,  as  in  the  body  of  another.  Sensation,  Thought, 
Emotion,  and  Volition,  however,  are  changes  imperceptible  to  our  senses  by  any  means  of 
observation  we  at  present  possess.  We  are  cognizant  of  them  in  ourselves,  without  the 
intervention  of  those  processes  by  which  we  observe  material  changes  external  to  our 
minds ;  but  we  judge  of  them  in  others  only  by  inferences  founded  on  the  actions  to  which 
they  give  rise,  when  compared  with  our  own.  When  we  speak  of  sensation,  thought, 
emotion,  or  volition,  therefore,  as  functions  of  the  Nervous  System,  we  mean  only  that 
this  system  furnishes  the  conditions  under  which  they  exist  in  the  living  body  ;  and  we 
leave  the  question  entirely  open,  whether  the  tv^ri  has  or  has  not  an  existence  independent 
•jf  that  of  the  material  organism,  by  which  it  operates  in  Man,  as  he  is  at  present  con- 
stituted. 


NATURE    AND     DESTINATION     OF    FOOD.  63 

CHAPTER  III. 

OF    FOOD,     AND    THE    DIGESTIVE    PROCESS. 
1.    Of  Food)  its  Nature  and  Destination. 

48.  THE  substances  which  are  required  by  Animals  for  the  development  and 
maintenance  of  their  fabric,  arc  of  two  kinds;  —  the  Organic  and  the  Inorganic. 
The  Organic  alone  are  commonly  reckoned  as  aliments  ;  but  the  latter  are  really 
not  less  requisite  for  the  sustenance  of  the  body,  which  speedily  disintegrates,  if 
the  attempt  be  made  to  support  it  upon  any  organic  compounds  in  a  state  of 
purity.      In  all  ordinary  articles  of  diet,  however,  the  Inorganic  matters  are 
present  in  the  requisite  proportion  ;  and  hence  it  is  that  the  necessity  which 
exists  for  their  employment  has  very  commonly  escaped  notice. 

49.  The  Organic  compounds  usually  employed  as  food  by  Man,  are  partly  de- 
rived from  the  Animal,  and  partly  from  tne  Vegetable  kingdom ;  and  they  may 
be  conveniently  arranged  under  the  four  following  heads:1  —  1.  The  Saccharine 
group,  including  all  those  substances,  derived  from  the  Vegetable  kingdom,  which 
are  analogous  in  their  composition  to  Sugar  ;  consisting  of  oxygen,  hydrogen,  and 
carbon  alone  ;  and  having  the  first  two  components  united  in  the  proportions  to 
form  water.     To  this  group  belong  starch,  gum,  woody  fibre,  and  the  cellulose  of 
Plants,  which  closely  resemble  each  other  in  the  proportion  of  their  elements, 
and  which  may  be  converted  into  Sugar  by  chemical  processes  of  a  simple  kind; 
whilst  Alcohol,  which  is  derived  from  Sugar  by  the  process  of  fermentation,  has 
a  composition  which  rather  connects  it  with  the  next  group. — 2.  The  Oleaginous 
group,  including  oily  matters,  whether  derived  from  the  Vegetable  kingdom  or 
from  tne  fatty  portions  of  Animal  bodies.     The  characteristic  of  this  class  lies 
in  the  great  predominance  of  hydrogen  and  carbon,  the  small  proportion  of  oxy- 
gen, and  the  entire  absence  of  nitrogen. —  3.  The  Albuminous  group,  comprising 
all  those  substances,  whether  derived  from  the  Animal  or  the  Vegetable  king- 
dom, which  are  closely  allied  to  Albumen,  and  through  it  to  the  Animal  tissues 
generally,  in  their  chemical  composition.     In  this  group  a  large  proportion  of 
azote  is  united  with  the  oxygen,  hydrogen,  and  carbon  of  the  preceding. — 4.  The 
Gelatinous  group,  consisting  of  substances  derived  from  the  animal  bodies  only, 
which  are  closely  allied  to  Gelatin  in  their  composition.     These  also  contain 
azote;  but  the  proportion  of  their  components  differs  from  that  of  the  preceding. 

-There  are  many  other  substances,  however,  which,  though  truly  alimentary, 
and  consumed  to  a  considerable  amount,  cannot  be  legitimately  placed  under  either 
of  the  above  heads ;  such  are,  for  example,  the  Vegetable  Acids,  and  Pectine  or 
vegetable  jelly. 

50.  The   compounds  of   the   Saccharine  group  cannot,  without  undergoing 
metamorphosis,  form  part  of  any  Animal  tissue ;  as  there  is  none  which  they  at 
all  resemble  in  composition.     They  are  convertible,  however,  within  the  animal 
body,  into  those  of  the  Oleaginous  group,  and  may  thus,  like  the  latter,  be  ap- 
plied to  the  formation  of  the  Adipose  and  Nervous  tissues.     But  the  amount  of 
these  substances  which  is  thus  employed,  is  a  very  small  part  of  that  which  in 
ordinarily  introduced  as  food ;  and  by  far  the  larger  proportion  of  them  is  made 
subservient  to  the  maintenance  of  the  Heat  of  the  body  by  the  combustive  pro- 
cess.    The  Sugar,  which  is  taken  in  as  such,  being  dissolved  and  absorbed  intc 
the  current  of  the  circulation,  appears  to  undergo  a  speedy  metamorphosis  intc 

1  Dr.  Front's  classification  of  alimentary  substances  is  here  adopted,  with  a  slight  modi- 
fication ;  not  as  being  altogether  unexceptionable,  but  as  being,  in  the  Author's  ophuou, 
the  most  convenient  hitherto  proposed. 


64  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

lactic  acid,  which  is  the  form  under  which  it  is  finally  oxidized  and  burned  off; 
and  Starch  is  made  capable  of  undergoing  the  same  change,  by  being  first  con- 
verted into  Sugar  during  the  digestive  process.  Oleaginous  matters  do  not  seem 
to  undergo  any  change  preliminary  to  their  oxidation,  save  their  reduction  to  a 
state  of  very  fine  division.  We  shall  presently  see  (§  54)  that  a  very  considera- 
ble difference  exists  between  the  Saccharine  and  the  Oleaginous  matters,  in  regard 
to  their  relative  calorifying  powers. — That  none  of  these  non-azotized  substances 
can  be  made  capable,  by  metamorphosis  or  combination  within  the  Animal  body, 
of  taking  the  place  of  the  azotized  substances  as  '  histogenetic'  or  'plastic'  com- 
pounds, may  now  be  regarded  as  one  of  the  most  certain  facts  in  Physiology } 
the  concurrent  evidence  of  experiment  and  observation  leading  to  the  conclusion, 
that  in  Plants  alone  can  any  production  of  azotized  compounds  take  place,  and 
that  Animals  are  in  consequence  directly  or  indirectly  dependent  upon  the  Vege- 
table kingdom  for  their  means  of  subsistence.  If  animals  be  fed  exclusively 
upon  Saccharine  or  Oleaginous  substances,  of  any  kind,  or  in  any  combination 
whatever,  they  speedily  perish  with  symptoms  of  Inanition  :  and  the  only  assist- 
ance which  such  food  affords  in  the  prolongation  of  life,  is  derived  from  its  calo- 
rific power  (§  27). 

51.  The  substances  forming  the  Albuminous  group  are  applicable  to  the 
support  of  the  Animal  body,  both  by  affording  the  materials  for  the  nutrition 
and  re-formation  of  its  tissues,  aud  also  by  serving  (if  required)  for  the  mainte- 
nance of  its  heat,  through  the  decomposition  of  which  they  are  susceptible,  into 
hydrocarboiiaeeous  matters  adapted  for  combustion  in  the  lungs,  and  highly 
azotized  compounds  which  pass  off  by  the  kidneys.  The  proportions  of  carbon, 
hydrogen,  oxygen,  and  nitrogen,  of  which  all  these  substances  are  composed, 
appear  to  be  identical ;  and  they  seem  all  capable  of  being  reduced  by  the  diges- 
tive process  to  a  like  condition.  Hence  it  is  a  matter  of  little  consequence, 
except  as  regards  the  proportion  of  inorganic  matters  with  which  they  may  be 
respectively  united,  whether  we  draw  our.  histogenetic  materials  from  the  flesh 
of  animals,  from  the  white  of  egg  (albumen),  from  the  curd  of  milk  (casein), 
from  the  grain  of  wheat  (gluten),  or  from  the  seed  of  the  pea  (legumin).  Nei- 
ther of  these  substances,  however,  can  long  sustain  life  when  it  is  used  by  itself; 
for  it  has  been  experimentally  ascertained,  that  by  being  made  to  feed  constantly 
on  the  same  substance  (boiled  white-of-egg,  for  instance,  or  meat  deprived  of  the 
osmazome  that  gives  it  flavour),  an  animal  may  be  effectually  starved ;  its  disgust 
at  such  food  being  such  that,  even  if  this  be  swallowed,  it  is  not  digested.1 — The 
organized  fabric  of  Animals  contains  also  a  large  quantity  of  Gelatin.  It  seems 
certain  that  this  substance  may  be  produced  out  of  fibrin  and  albumen ;  since  in 
unimals  that  are  supported  on  these  alone,  the  nutrition  of  the  gelatinous  tissues 
does  not  seem  to  be  impaired.  But  it  has  been  commonly  supposed  that  gelatin 
taken  in  as  food  may  serve  for  the  growth  and  maintenance  of  these  tissues  ;  even 
though  it  may  be  incapable  of  conversion  to  the  albuminous  type.  It  is  very 
doubtful,  however,  whether  Gelatin  can  render  even  this  service.  For  all  our 
knowledge  of  the  history  of  the  development  of  the  Gelatinous  tissues  would 
lead  us  to  regard  them  as  secondary  products,  which  take  their  origin  in  a  fibrinous 
blastema,  and  can  only  be  generated  by  the  metamorphosis  of  protein  compounds. 
(See  PRINC.  OF  GEN.  PHYS.)  If  this  view  be  correct,  it  follows  that  the  ali- 
mentary value  of  gelatin  must  be  limited  to  its  calorific  power;  its  hydro- 

1  It  is  very  interesting  to  remark  (with  Dr.  Prout)  that,  in  the  only  instance  in  which 
Nature  has  provided  a  single  article  of  food  for  the  support  of  the  animal  body,  she  has 
mingled  articles  from  the  first  three  of  the  preceding  groups.  This  is  the  case  in  Milk, 
which  contains  a  considerable  quantity  of  an  albuminous  substance,  casein,  which  forms 
its  curd;  a  good  deal  of  oily  matter,  the  butter;  and  no  inconsiderable  amount  of  sugar, 
which  is  dissolved  in  the  whey.  The  proportions  of  these  vary  in  different  Mammalia,  and 
thoy  depend  in  part  upon  the  nature  of  the  food  supplied  to  the  animal  that  forms  the 
milk;  but  the  substances  are  thus  combined  in  every  instance. 


NATURE  AND  DESTINATION  OF  FOOD.         C"> 

carbon  being  separated  from  its  highly  azotized  portion,  and  the  former  being 
oxidized  and  eliminated  through  the  lungs,  whilst  the  latter  will  pass  off  by  the 
kidneys.  And  such  a  deduction  is  confirmed  by  the  observations  of  Frerichs,  on 
the  result  of  the  ingestion  of  large  quantities  of  pure  gelatin ;  this  being  a 
marked  increase  in  the  proportion  of  urea  in  the  urine,  with  an  elevation  of 
its  specific  gravity  from  1018  to  1030,  or  even  1034 ;  so  that,  as  neither  leu- 
cine  nor  glycine  could  be  detected  in  the  fluid,  Gelatin  seems  to  be  subjected  to 
the  same  metamorphosis  that  the  protein  compounds  undergo  when  they  are  taken 
in  excess.1  —  That  Gelatin  cannot  take  the  place  of  the  albuminous  compounds, 
has  been  fully  demonstrated  by  the  inquiries  of  the  Commissions  which  have  been 
appointed  to  investigate  the  subject  in  Paris  and  Amsterdam.2  In  so  far,  there- 
fore, as  the  only  azotized  principles  contained  in  soups,  broths,  &c.,  are  of  the 
gelatinous  character,  we  must  account  these  preparations  as  destitute  of  the  power 
of  nourishing  the  body  ]  and  the  peculiar  nutritive  value  which  experience  shows 
that  such  preparations  possess  in  certain  states  of  the  system,  must  be  attributed 
to  the  albuminous  matters  which  they  hold  in  solution,  and  to  the  readiness  with 
which  their  gelatinous  constituents  are  absorbed  and  applied  (by  the  decomposi- 
tion just  explained)  to  the  purpose  of  calorification.3 

52.  The  substances  which  cannot  be  arranged  under  either  of  the  preceding 
groups,  are,  for  the  most  part,  of  the  Non-azotized  class;  and,  as  they  mostly 
consist  of  compounds  in  which  the  hydrogen  and  carbon  are  not  combined  with 
their  full  equivalents  of  oxygen,  they  are  made  to  contribute  to  the  calorifying 
process  by  undergoing  oxidation  within  the  system,  so  as  to  be  excreted  in  the 
form  of  carbonic  acid  and  water. 

53.  By  rules  based  on  the  foregoing  data,  then,  we  may  estimate  the  relative 
value  of  different  articles  of  food,  for  the  two  distinct  purposes  of  the  formation 
of  tissue  and  the  production  of  heat.     For  the  proportion  of  Albuminous  matter 
which  any  substance  may  contain,  furnishes  the  measure  of  its  histogenetic  value ; 
whilst  the  proportion   of  Hydro-Carbon   uncombined  with   oxygen,  affords  the 
means  of  estimating  its  calorific  power  when  oxidized.     Since,  in  almost  every 
alimentary  substance  whether  vegetable  or  animal,  these  two  classes  of  compounds 
are  mingled,  the  per-centage  of  nitrogen  (save  in  those  substances  into  which  Gela- 
tin enters  largely)  which  it  may  contain,  affords  a  tolerably  correct  measure  of 
the  amount  of  albuminous  matter  which  it  includes,  and  therefore  of  its  Jiistoye- 
netic  value :  where,  on  the  other  hand,  the  per-centage  of  nitrogen  is  the  smallest, 
that  of  hydro-carbon  is  the  largest,  and  the  proportion  of  the  combustive  material 
is  the  highest.  The  following  Table4  specifies  this  proportion  in  the  case  of  various 
articles  used  as  food;  Human  Milk  being  taken  as  the  standard  of  comparison,  and 
the  quantity  of  nitrogen  it  contains  being  expressed  by  100.     It  must  be  borne 
in  mind,  however,  that  this  substance  is  intended  for  the  nourishment  of  a  being 
which  passes  nearly  the  whole  of  its  time  in  a  quiescent  state,  and  must  not  be 
supposed  to  be  equally  well  adapted  for  the  sole  maintenance  of  the  Human  body 
in  a  state  of  activity.     In  fact,  it  is  inferior  in  its  proportion  of  Casein  (the  sub- 
stance of  which  alone  the  azote  forms  a  part)  to  the  milk  of  other  Mammalia, 
whose  young  bring  their  animal  functions  into  exercise  at  a  much  earlier  period 
than  does  the  Human  infant.  —  The  proportions  are  those  existing  in  the  dry 
solids. 

1  See  Frerichs'  article  Verdauung  in  "Wagner's  Handworterbuch,"  band  iii.,  p.  684. 

3  See  the  Report  of  the  French  'Gelatin  Commission,'  in  the  "Compt.  Rend.,"  Aout> 
1841 ;  and  that  of  the  Amsterdam  Commission,  in  "  Het.  Instituut,"  No.  2,  1843,  and 
"  Gazette  M6dicale,"  Mars  16,  1844. 

•  The  common  notion  of  the  great  nutritive  value  of  soups,  &c.,  -whose  supposed 
1  strength '  is  indicated  by  the  firmness  with  \vhich  they  gelatinize  on  cooling,  is  one  of 
th^se  popular  dietetic  prejudices,  of  which  it  is  peculiarly  incumbent  on  the  Medical  Pro- 
fession to  disabuse  their  patients. 

4  Schlossberger  and  Kemp,  in  "  Philosophical  Magazine,"  Nov.  1845. 

5 


66 


OP  FOOD,  AND  THE  DIGESTIVE  PROCESS. 


Rice  ..........................     81 

Potatoes  ....................     84 

Turnips  .....................  106 

Re  ..........................   106 


Maize 


Vegetable. 

Barley  .......................   125 

Oats  .........................  138 

White  bread  ...............   142 

Wheat  .................   119-144 


100-125     Carrots 150     Beans 


Brown  bread  ...............  166 

Peas  ..........................  239 

Haricot  beans  .............  283 

Agaricus  deliciosus  ......  289 


320 


Animal. 


Human  milk 100  \  Salmon,  boiled. 

Cow's  milk 237 

Oyster 305 

Yolk  of  eggs 305 

Cheese 331-447 

Eel,  raw 434 

Mussel,  raw 528 

Ox  liver,  raw 570 

Pork  ham,  raw 539 

boiled 807 

Salmon,  raw 776 


....  610 

Portable  soup 764 

White  of  egg 845 

Crab,  boiled 859 

Skate,  raw 859 

boiled 956 

Herring,  raw 910 

boiled 808 


Haddock,  raw 920 

boiled 816 

Flounder,  raw 898 


Flounder,  boiled 954 

Pigeon,  raw 756 

boiled 827 


Lamb,  raw 833 

Mutton,  raw 773 

boiled 852 

Veal,  raw 873 

boiled 911 

Beef,  raw 880 

boiled 942 

Ox  lung 931 


It  is  not  to  be  supposed,  however,  that  any  table  of  this  kind,  founded  simply 
upon  the  Chemical  composition  of  the  various  substances,  can  indicate  their  respec- 
tive fitness  as  articles  of  diet;  since  this  depends  also  upon  the  facility  with  which 
they  are  reduced  by  the  digestive  process,  and  afterwards  assimilated.  Thus  an 
aliment  abounding  in  nutritive  matter,  may  be  inferior  to  one  which  really  con- 
tains a  much  smaller  proportion,  if  only  a  part  in  the  first  case,  and  the  whole  in 
the  second,  be  readily  taken  up  by  the  system. 

54.  The  calorific,  powers  of  the  substances  above  enumerated,  however,  are  not 
precisely  in  the  inverse  ratio  to  their  histogenetic  value ;  for,  as  the  amount  of 
heat  given  off  in  their  combustion  depends,  not  simply  upon  the  amount  of  carbon 
and  hydrogen  they  may  contain,  but  upon  the  excess  of  their  hydro-carbon  over 
and  above  that  which  is  already  combined  with  oxygen,  substances  that  are  alike 
deficient  in  nitrogen  may  differ  considerably  in  this  respect.     Thus  in  ordinary 
fat,  the  proportion  of  oxygen  is  only  about  10  per  cent,  whilst  that  of  hydro-car- 
bon is  at  least  90  per  cent;  in  alcohol,  the  proportion  of  oxygen  is  nearly  35  per 
cent  to  65  per  cent  of  hydro-carbon ;  in  starch,  the  oxygen  is  49|  per  cent,  the 
hydro-carbon  50f  per  cent;  in  cane  sugar,  the  oxygen  is  51£,  the  hydro-carbon 
48  i  ;  and  in  grape  sugar,  the  oxygen  is  53 £,  the  hydro-carbon  46f.     According 
to  the  estimate  of  Prof.  Liebig,1  the  following  are  the  relative  calorific  powers 
of  these   s-ubstances;    the   numbers   expressing   approximately  the  weights   of 
each  which  must  be  taken  in  as  food,  in  order,  with  the  same  consumption  of 
oxygen,  to  keep  the  body  at  its  proper  temperature  during  equal  times :  —  fat, 
100;  starch,  240;  cane  sugar,  249;  grape  sugar,  263;  spirits  (containing  50  per 
cent  of  absolute  alcohol),  266.     The  equivalent  of  lean  flesh  required  to  produce 
the  same  calorific  effect  with  the  foregoing,  would  be  no  less  than  770. 

55.  It  is  obvious  that  the  most  economical  diet  will  be  that  in  which  there  is 
the  most  perfect  apportionment  of  each  class  of  constituents  to  the  wants  of  the 
system;  and  these,  on  the  principles  already  explained  (§§  26,  27),  will  vary  with 
the  amount  of  muscular  exertion  put  forth,  and  with  the  elevation  or  depression 
of  the  external  temperature.     Thus,  for  a  man  of  ordinary  habits,  and  living 
under  a  medium  temperature,  a  diet  composed  of  animal  flesh  alone  is  the  least 
economical  that  can  be  conceived ;  for,  since  the  greatest  demand  for  food  in  his 
system  is  created  by  the  necessity  for  a  supply  of  carbon  and  hydrogen  to  support 
his  respiration,  this  want  may  be  most  advantageously  fulfilled  by  the  employ- 
ment of  a  certain  quantity  of  non-azotized  food,  in  which  these  ingredients  pre- 
dominate.    Thus  it  has  been  calculated,  that,  since  fifteen  pounds  of  flesh  contain 
no  more  carbon  than  fuur  pounds  of  starch,  a  savage  with  one  carcase  and  an  equal 

1  "Familiar  Letters  on  Chemistry,"  3d  edit,  p.  380. 


NATURE  AND  DESTINATION  OF  FOOD.         67 

weight  of  starch,  could  support  life  for  the  same  length  of  time,  during  which 
another  restricted  to  animal  food  would  require  five  such  carcases,  in  order  to  pro- 
cure the  carbon  necessary  for  respiration.  Hence  we  see  the  immense  advantage 
as  to  economy  of  food,  which  a  fixed  agricultural  population  possesses  over  those 
wandering  tribes  of  hunters,  which  still  people  a  large  part  both  of  the  Old  and 
New  Continents.  The  mixture  of  the  azotized  and  non-azotized  compounds 
(gluten  and  starch),  that  exists  in  wheat  flour,  seems  to  be  just  that  which  is  most 
generally  useful  to  Man;  and  hence  we  see  the  explanation  of  the  fact,  that,  from 
very  early  ages,  bread  has  been  regarded  as  the  "  staff  of  life."  —  There  are  par- 
ticular conditions  of  existence,  however,  under  which  life  may  be  advantageously 
supported  upon  animal  food  alone.  Thus  the  Guachos  of  South  America,  who 
pass  the  whole  day  in  the  saddle,  and  lead  a  life  of  constant  activity  resembling 
that  of  a  carnivorous  animal,  scarcely  ever  taste  anything  but  beef;  and  of  this 
their  consumption  is  by  no  means  great;  for  the  temperature  of  the  surrounding 
atmosphere  is  so  high,  that  the  body  has  no  occasion  to  generate  more  heat  than 
is  supplied  by  the  combustion  of  the  hydro-carbonaceous  portion  of  the  l  waste' 
of  the  tissues.  Here,  then,  the  demand  for  histogenetic  material  being  at  its 
maximum,  and  that  for  combustive  materials  at  its  minimum,  the  former  supplies 
all  that  is  requisite  for  the  latter.  Again,  the  Esquimaux  and  other  dwellers 
upon  the  Arctic  seas  find  in  the  bodies  of  the  whales,  seals,  &c.,  whereon  they 
subsist,  that  special  supply  of  the  very  best  combustive  material,  which  alone  can 
enable  them  to  maintain  their  existence  in  a  climate,  where  the  thermometer  is 
for  many  weeks  or  months  in  the  year  at — 40°  or  even  lower,  and  where  the 
amount  of  heat  which  must  be  generated  within  the  body  is  four  or  five  times  that 
for  which  a  diet  of  bread  will  suffice.  —  On  the  other  hand,  the  general  experience 
of  the  inhabitants  of  warm  climates  seems  in  favour  of  a  diet  chiefly  or  entirely 
vegetable;  and  its  peculiar  suitableness  appears  to  consist  in  its  affording  an 
adequate  supply  of  the  plastic  alimentary  substances,  in  combination  with  farina- 
ceous matters  that  give  the  requisite  bulk  to  the  food  (§  104),  without  affording 
more  combustive  material  than  the  system  requires,  —  the  quantity  of  starch 
which  undergoes  conversion,  and  which  is  introduced  as  sugar  into  the  circula- 
tion, being  apparently  governed  rather  by  the  demands  of  the  respiratory  pro- 
cess, than  by  the  amount  ingested;  and  the  remainder  being  voided  again  un- 
changed. 

56.  The  mixed  diet,  to  which  the  inclination  of  Man  in  temperate  climates 
seems  usually  to  lead  him  (when  circumstances  allow  that  inclination  to  develope 
itself  freely),  appears  to  be  fully  conformable  to  the  construction  of  his  dental  and 
digestive  apparatus,  as  well  as  to  his  instinctive  propensities.  And  whilst,  on 
the  one  hand,  it  may  be  freely  conceded  to  the  advocates  of  '  Vegetarianism/  that 
a  well-selected  vegetable  diet  is  capable  of  producing  (in  the  greater  number  of 
individuals)  the  highest  physical  development  of  which  they  are  capable,  it  may 
on  the  other  hand  be  affirmed  with  equal  certainty,  that  the  substitution  of  a 
moderate  proportion  of  animal  flesh  is  in  no  way  injurious,  whilst,  so  far  as  our 
evidence  at  present  extends,  this  seems  rather  to  favour  the  highest  mental  deve- 
lopment. If,  indeed,  we  take  a  comprehensive  survey  of  the  conditions  of  the 
various  races  of  Man  at  present  inhabiting  the  earth,  we  cannot  help  being  struck 
with  his  adaptiveness  to  a  great  variety  of  circumstances,  as  regards  climate,  mode 
of  life,  diet,  &c.  And  we  can  scarcely  avoid  the  conclusion,  that  the  Creator,  by 
conferring  upon  him  such  an  adaptiveness,  intended  to  qualify  him  for  subsisting 
on  those  articles  of  diet,  whether  animal  or  vegetable,  which  are  most  readily 
attainable  in  different  parts  of  the  globe ;  arid  thus  to  remove  the  obstacle  which 
a  necessary  restriction  to  any  one  kind  of  food  would  have  otherwise  opposed  to 
his  universal  diffusion.  If  we  were  to  bring  together  the  habitual  diet  scales  of 
the  several  races  of  Men  which  people  the  surface  of  our  globe,  we  apprehend 
that  the  diversities  which  they  would  present  would  be  scarcely  less  strange  than 
those  which  exist  among  the  regimens  of  the  most  dissimilar  species  of  Mamma- 


68  OF    FOOD,    AND    THE    DIGESTIVE     PROCESS. 

lia.  We  should  find  the  purely  animal-feeding  on  the  one  hand,  the  pure  vege- 
tarians on  the  other.  Among  the  former  we  should  find  some  who  devour  animal 
flesh,  others  fish,  and  others  fowl,  while  others  are  even  insectivorous;  then, 
again,  we  should  encounter  some  who  devour  their  food  raw,  others  who  cook  it ; 
.some  preferring  it  immediately  that  has  ceased  to  live,  while  others  do  not  relish 
it  until  it  has  become  almost  putrescent.  So  among  the  vegetable  feeders,  we 
should  find  some  subsisting  upon  soft  fruits,  others  upon  hard  grains,  others  again 
chiefly  upon  succulent  herbage,  and  others  upon  roots  so  tough  as  to  require  arti- 
ficial means  for  their  reduction.  In  the  various  devices  by  which  Man  has  suc- 
ceeded in  availing  himself  of  these,  and  in  the  various  tastes  which  have  led  some 
to  avail  themselves  of  articles  of  food  which  others  would  loathe,  we  see  the  evi- 
dence of  the  same  wise  Design,  as  that  which  has  given  to  different  tribes  of 
animals  their  respective  preferences ;  and  we  deduce  from  the  whole  the  conclu- 
sion, that  Man  is  left  by  his  Creator  at  perfect  liberty  to  select  that  kind  of  nutri- 
ment which  he  finds  most  suitable  to  his  tastes  and  to  his  wants;  the  former,  when 
not  absolutely  vicious,  being  (there  is  strong  reason  to  believe)  an  exponent  of 
the  latter,  just  as  the  simple  desire  for  food  is  the  exponent  of  the  need  for  it  in 
the  system. 

57.  When  the  results  of  Experience,  then,  are  combined  with  the  teachings  of 
Science,  they  seern  to  justify  the  following  conclusions. 

I.  That  a  due  adjustment  of  the  Albuminous,  Oleaginous,  and  Saccharine  con- 
stituents of  the  food,  to  the  varying  conditions  under  which  Man  exists,  is  of  the 
first  importance;  whilst  the  question  of  the  derivation  of  the  first  two  of  these 
constituents  from  the  Animal  or  from  the  Vegetable  kingdom,  is  one  of  secondary 
character;  each  being  capable  of  yielding  them  an  adequate  amount,  and  the  only 
condition  requisite  being,  that  the  articles  of  food  shall  be  so  selected  as  to  supply 
the  needful  quantity.  Thus  a  diet  whose  staple  consists  of  potatoes  or  rice,  con- 
tains by  far  too  small  an  amount  of  albuminous  matter  in  proportion  to  the  farina- 
ceous ;  but  if  to  this  be  added  a  moderate  quantity  of  meat,  the  proportion  is 
assimilated  to  that  which  exists  in  wheateri  bread,  which  may  be  taken  as  the 
standard  for  Man's  alimentation  in  all  but  extremely  cold  climates.  The  failure 
of  wheaten  bread  to  supply  what  the  system  there  requires,  depends  on  nothing 
else  than  its  deficiency  in  the  oleaginous  constituent;  for  although  such  a  craving 
for  fat  meat  is  experienced  by  travellers  in  those  climates,  as  has  led  to  the  belief 
that  it  is  necessary  for  their  support,  yet  recent  experience  has  shown  that  a  vege- 
table oil  answers  the  same  purpose,  bread  made  from  maize  flour  (which  contains 
a  large  proportion  of  oleaginous  matter)  having  been  found  to  be  just  as  effica- 
cious as  fat  meat,  both  in  supporting  the  muscular  strength,  and  in  maintaining 
the  heat  of  the  body.1  On  the  other  hand,  maize  bread  is  found  by  experience  to 
be  far  less  adapted  than  wheaten  bread  for  consumption  in  warm  climates,  being 
too  'heating'  in  its  character;  thus  confirming  the  view  already  stated,  as  to  the 
superiority  of  farinaceous  matter  as  the  principal  combustive  material,  where  the 
external  temperature  is  high.  —  The  same  kind  of  difference  should  be  made  in 
the  winter  and  summer  diet  of  the  inhabitants  of  the  temperate  zone.  For  when 
the  external  temperature  is  low,  an  ample  supply  of  oleaginous  matter  is  indi- 
cated, and  may  be  advantageously  taken  in  the  form  of  butter,  cocoa,  fat  meat,  or 
maize  bread.  On  the  other  hand,  during  the  heat  of  summer,  the  more  nearly 
the  diet  is  assimilated  to  that  of  the  natives  of  tropical  climates,  in  the  substitu- 
tion of  fruits  and  farinacea  for  oleaginous  articles,  the  less  will  be  the  liability  to 
disordered  health  in  the  autumn.2 

1  The  Author  makes  this  statement  on  the  authority  of  Sir  J.  Richardson,  who  informs 
him  that  2^  Ibs.  of  maize  flour  may  be  considered  as  the  equivalent  of  8  Ibs.  of  meat. 

*  There  can  be  no  doubt  that  a  large  proportion  of  the  diseases  of  the  digestive  appa- 
ratus, which  are  so  fatal  among  European  residents  in  India  and  other  tropical  climates, 
result  from  the  habitual  ingestion  of  a  much  larger  quantity  of  food,  and  this  especially  of 
a  rich  and  stimulating  character,  than  the  system  requires.  The  loss  of  appetite  conse- 


NATURE    AND    DESTINATION     OF    FOOD.  69 

II.  Experience  teaches,  however,  that  it  is  not  a  matter  of  entire  indifference, 
whether  the  Albuminous  constituent  be  drawn  from  the  Animal  or  from  the 
Vegetable  kingdom ;  for  the  use  of  a  highly-animalized  diet  has  a  tendency  to 
raise,  and  that  of  a  vegetable  diet  to  lower,  the  proportion  of  red  corpuscles  in 
the  Blood  (§  177);  whilst,  by  a  due  adjustment  of  the  proportion  of  the  two 
classes  of  components,  the  evil  effects  of  the  exclusive  use  of  either  may  be  pre- 
vented. 

in.  So,  again,  Experience  teaches  what  could  scarcely  have  been  anticipated 
theoretically  ;  —  namely,  that,  notwithstanding  the  power  which  the  living  body 
possesses,  of  converting  saccharine  compounds  into  oleaginous,  the  ingestion  of  a 
certain  amount  of  Oleaginous  matter  as  such  is  necessary,  or  at  least  is  favourable, 
to  the  maintenance  of  health.  We  see  this  provided  in  large  quantity,  in  the  first 
aliment  prepared  by  nature  for  the  offspring  of  the  Mammalia;  and  it  exists- 
largely  in  the  yolk  of  the  egg  of  all  Oviparous  animals.  In  the  ordinary  diet  of 
every  nation  on  the  globe,  —  whether  this  be  animal,  vegetable,  or  mixed,  —  we 
find  one  or  more  articles  of  an  oleaginous  nature ;  and  there  is  a  natural  craving 
for  such  substances  when  they  are  completely  withheld,  which  indicates  that  they 
serve  some  important  purpose  in  the  economy.  Although  this  craving  is  so  far 
affected  by  climate,  that  it  leads  to  the  largest  consumption  of  oily  matter  where 
the  extreme  of  cold  has  to  be  endured,  it  exists  with  no  less  intensity  even  in 
tropical  regions;  and  we  find  the  Hindoo  adding  his  modicum  of  'ghee'  (or 
rancid  butter)  to  the  rice  which  constitutes  his  staple  article  of  diet,  with  the 
same  relish  that  the  Esquimaux  feels  for  his  massive  lumps  of  blubber.  —  It  does 
not  seem  difficult  to  understand  the  rationale  of  this  fact.  For  whilst  the  Adi- 
pose and  Nervous  tissues  are  the  only  portions  qf  the  Animal  fabric  into  which 
fatty  matters  enter  in  any  considerable  proportion,  yet  its  presence  has  an  im- 
portant influence  on  the  assimilation  of  albuminous  matters,  and  seems  essential 
to  every  act  of  cytogenesis  (see  PRINC.  of  GEN.  PHYS.)  We  shall  hereafter  see 
(§  135)  that  it  is  probably  in  the  Lacteal  system,  that  the  two  substances  are 
brought  into  that  mutual  relation  with  each  other,  which  these  purposes  require; 
and  thus  it  is  obvious  that,  unless  a  conversion  of  saccharine  into  oleaginous  mat- 
ter can  take  place  in  the  alimentary  canal  (of  which  there  is  no  adequate  evi- 
dence), no  true  chyle  can  be  formed,  except  when  oleaginous  matters  have  formed 
part  of  the  food.  There  is  strong  and  increasing  reason  to  believe,  that  a  defi- 
ciency of  oleaginous  matter,  in  a  state  fit  for  appropriation  by  the  nutritive  pro- 
cesses, is  a  fertile  source  of  diseased  action,  especially  of  that  of  a  tuberculous 
character ;  and  that  the  habitual  use  of  it  in  a  larger  proportion  would  operate 
favourably  in  the  prevention  of  such  maladies,  as  the  employment  of  cod-liver  oil 
unquestionably  does  in  their  cure.  A  most  remarkable  example  of  this  is  pre- 
sented by  the  population  of  Iceland ;  which,  notwithstanding  the  concurrence  of 
every  one  of  the  circumstances  usually  considered  favourable  to  the  scrofulous 
diathesis,  enjoys  a  most  remarkable  immunity  from  it,  —  without  any  other 
assignable  cause  than  the  peculiarly  oleaginous  character  of  the  diet  usually  em- 
ployed. l  , 

IV.  Another  of  the  results  of  Experience,  of  which  Science  has  not  yet  given 
a  definite  rationale,  is  the  necessity  of  employing  fresh  vegetables  as  an  article  of 

quent  upon  the  diminution  of  the  demand  for  combustive  material,  is  set  down  to  the  dele- 
terious influence  of  the  climate ;  and  an  attempt  is  made  to  neutralize  this  by  artificial 
provocatives.  —  So,  it  seems  probable  that  many  of  the  'bilious  attacks,'  which,  in  this 
country,  are  so  frequent  in  early  autumn,  and  which  are  commonly  set  down  to  the  account 
of  fruit  (although  the  subjects  of  them  have  often  abstained  entirely  from  that  article),  are 
really  the  result  of  the  presence  of  an  excess  of  hydro-carbonaceous  matter  in  the  system, 
consequent  upon  over-feeding  during  the  summer,  and  must  be  looked  upon  as  the  natural 
means  by  which  it  is  got  rid  of. 

1  See  Dr.  Schleisner's  "  Island  undersogt  fra  laegevidenskabeligt  Synspunct,"  or  Report 
on  the  Sanitary  Condition  of  Iceland;  and  the  analysis  of  it  in  the  "Brit,  and  For.  Med. 
Chir.  Rev.,"  vol.  v.  p.  456. 


70  OF    FOOD,     AND     THE     DIGESTIVE     PROCESS. 

Diet;  the  almost  invariable  consequence  of  the  entire  omission  of  them,  being 
the  development  of  that  peculiar  constitutional  disorder  which  is  known  as 
Scurvy.  That  the  deficiency  of  something  which  fresh  vegetables  can  alone  sup- 
ply, is  the  essential  cause  of  this  disease  (its  operation  being  promoted,  however, 
by  other  conditions,  such  as  absolute  deficiency  of  food,  confinement,  bad  venti- 
lation, depression  of  spirits,  &c.),  may  now  be  regarded  as  a  well-established  fact;1 
and  it  is  one  which  ought  to  have  an  important  influence  on  our  dietetic  arrange- 
ments. For  if  the  total  withdrawal  of  these  articles  be  productive  of  such  a  fear- 
ful depravation  of  the  blood,  as  perverts  every  function  to  which  the  blood  is 
subservient,  a  diminution  of  them  below  the  standard  requisite  for  the  mainte- 
nance of  health  must  necessarily  involve  a  depravation  similar  in  kind  though 
less  aggravated  in  degree ;  and  this,  if  slight,  may  be  expected  to  manifest  itself, 
not-  so  much  in  the  production  of  idiopathic  disorders,  as  in  favouring  any  pecu- 
liar tendency  to  disease  which  may  exist  in  the  system,  and  in  preventing  or 
retarding  recovery  from  its  effects.2  The  employment  of  fresh  fruits  and  of  green 
vegetables  seems  especially  indicated,  where  a  general  chronic  disorder  of  nutri- 
tion indicates  a  perverted  condition  of  the  circulating  material;  and  especially 
where  there  is  a  disposition  to  chronic  inflammation,  induration,  and  ulceration, 
in  different  parts  of  the  body. 

v.  Finally,  then,  a  well-arranged  dietetic  scheme  ought  to  consist  of  such  a 
combination  of  the  Albuminous,  Oleaginous,  and  Farinaceous  constituents,  as  is 
most  appropriate  to  the  requirements  of  the  system ;  —  a  larger  measure  of  the 
albuminous  being  supplied,  when  an  unusual  amount  of  nervo-muscular  exertion 
is  put  forth,  and  this  supply  being  then  most  advantageously  derived  from  animal 
flesh ;  —  a  larger  measure  of  the  oleaginous  being  required  for  the  sustentation  of 
the  heat  in  a  frigid  atmosphere,  and  this  being  supplied  equally  well  by  the  vege- 
table kingdom  as  by  the  animal ;  —  and  a  larger  proportion  of  the  farinaceous,  as 
a  substitute  for  the  oleaginous,  being  most  favourable  to  health  under  a  high 
atmospheric  temperature.  An  habitual  excess  in  the  use  of  either  of  these  con- 
stituents, above  what  the  demands  of  the  system  require,  tends  towards  the  pro- 
duction of  a  particular  'diathesis'  or  constitutional  state,  which  may  manifest 
itself  in  a  great  variety  of  modes.  Thus,  an  excess  of  the  albuminous  compo- 
nents, such  as  is  only  likely  to  occur  when  too  large  a  proportion  of  animal  food 
is  employed,  undoubtedly  favours  the  arthritic  diathesis,  which  seems  to  consist 
in  the  presence  of  imperfectly-assimilated  histogenetic  substances  and  wrongly- 
metamorphosed  products  of  disintegration,  that  are  not  duly  eliminated  in  the 
kidneys ;  and  this  diathesis  not  only  displays  itself  in  gout  and  gravel,  but 
modifies  the  course  of  other  diseases.  So  again,  an  excess  of  the  oleaginous  con- 
stituents of  the  food  tends  to  the  production  of  the  bilious  diathesis,  in  which, 
through  the  insufficient  elimination  of  hydrocarbonaceous  matters,  the  blood 
becomes  charged  with  the  elements  of  bile.  The  excess  of  farinacemis  matters, 
moreover,  especially  when  combined  with  a  deficiency  of  the  albuminous  (as  it 
too  frequently  is  among  those  who  are  obliged  by  necessity  to  live  chiefly  upon 
a  'poor'  vegetable  diet),  tends  to  the  production  of  the  rheumatic  diathesis; 
which  seems  to  consist,  like  the  arthritic,  in  the  mal-assimilation  and  wrong 
metamorphosis  of  the  components  of  the  tissues,  but  to  be  especially  favoured 
by  the  presence  either  of  lactic  acid,  or  of  some  other  product  of  the  meta- 
morphosis of  the  saccharine  compounds.  And,  as  already  pointed  out,  the  de- 
ficiency of  oleaginous  matters  seems  to  tend  to  the  development  of  the  scrofu- 

1  For  a  full  inquiry  into  this  subject,  see  the  "  Brit,  and  For.  Med.  Chir   Rev.,"  vol.  ii. 
p.  439. 

2  This  '  scorbutic  tendency'  was  fully  recognized  by  the  past  generation  of  Physicians, 
who  practised  in  those  good  old  times,  when  potatoes  were  a  luxury  and  green  vegetables 
in  the  winter  almost  unknown,  when  the  middle  classes  fed  upon  salted  meat  during  a 
great  part  of  the  year,  and  when  sagacious  old  women  prescribed  nettle  tea  and  scurvy 
grass,  with  a  course  of  lenitive  '  spring  physic,'  for  the  'cleansing  of  the  blood.' 


NATURE    AND     DESTINATION    01     FOOD.  71 

lous  diathesis ;  and  that  of  fruits  and  fresh  vegetables  to  the  production  of  the 
scorbutic.1 

58.  The  absolute  quantity  of  Food  required  for  the  maintenance  of  the  Human 
body  in  health,  varies  so  much  with  the  age,  sex,  constitution,  and  habits  of  the  in- 
dividual, and  with  the  circumstances  in  which  he  may  be  placed,  that  it  would  be  ab- 
surd to  attempt  to  fix  any  standard  which  should  apply  to  every  particular  case.  The 
appetite  is  the  only  sure  guide  for  the  supply  of  the  wants  of  each ;  but  its  indi- 
cations must  not  be  misinterpreted.     To  eat  when  we  are  hungry,  is  an  evidently 
natural  disposition ;  but  to  eat  as  long  as  we  are  hungry,  may  not  always  be  pru- 
dent.    Since  the  feeling  of  hunger  does  not  depend  so  much  upon  the  state  of 
fulness  or  emptiness  of  the  stomach,  as  upon  the  condition  of  the  general  system, 
it  appears  evident  that  the  ingestion  of  food  cannot  at  once  produce  the  effect  of 
dissipating  it,  though  it  will  do  so  after  a  short  time ;  so  that,  if  we  eat  with  un- 
due rapidity,  we  may  continue  swallowing  food  long  after  we  have  taken  as  much 
as  will  really  be  required  for  the  wants  of  the  system  ;  and  every  superfluous  par- 
ticle is  not  merely  useless,  but  injurious.     Hence,  besides  its  other  important 
ends,  the  process  of  thorough  mastication  is  important,  as  prolonging  the  meal, 
and  thus  giving  time  to  the  system  to  be  made  acquainted  (as  it  were)  that  the 
supply  of  its  wants  is  in  progress;  so  that  its  demand  may  be  abated  in  due  time 
to  prevent  the  ingestion  of  more  than  is  required.     It  is  very  justly  remarked  by 
Dr.  Beaumont,  that  the  cessation  of  this  demand,  rather  than  the  positive  sense 
of  satiety,  is  the  proper  guide.     "  There  appears  to  be  a  sense  of  perfect  intelli- 
gence conveyed  to  the  encephalic  centre,  which,  in  health,  invariably  dictates 
what  quantity  of  aliment  (responding  to  the  sense  of  hunger  and  its  due  satisfac- 
tion) is  naturally  required  for  the  purposes  of  life ;  and  which,  if  noticed  and 
properly  attended  to,  would  prove  the  most  salutary  monitor  of  health,  and  effec- 
tual preventive  of  disease.     It  is  not  the  sense  of  satiety,  for  this  is  beyond  the 
point  of  healthful  indulgence,  and  is  Nature's  earliest  indication  of  an  abuse  and 
overburden  of  her  powers  to  replenish  the  system.     It  occurs  immediately  pre- 
vious to  this ;  and  may  be  known  by  the  pleasurable  sensations  of  perfect  satis- 
faction, ease,  and  quiescence  of  body  and  mind.     It  is  when  the  stomach  says, 
enough;  and  it  is  distinguished  from  satiety  by  the  difference  of  sensations, — 
the  latter  saying  too  much."     Every  medical  man  is  well  aware  how  generally  this 
rule  is  transgressed ;  some  persons  making  a  regular  practice  of  eating  to  reple- 
tion ;  and  others  paying  far  too  little  attention  to  the  preliminary  operations,  and 
thus  ingesting  more  than  is  good  for  them,  even  though  they  may  actually  leave 
off  with  an  appetite. 

59.  Although  no  universal  law  can  be  laid  down  for  individuals,  it  is  a  matter 

1  It  is  worthy  of  remark  that  in  the  times  when  even  the  wealthy  lived  during  four  or 
five  months  of  the  year  almost  exclusively  upon  meat,  bread,  and  flour  puddings,  and  when, 
therefore,  the  diet  was  far  too  highly  azotized,  as  well  as  deficient  in  fresh  vegetables, 
Arthritic,  Calculous,  and  Scorbutic  disorders  were  much  more  common  than  at  present. 
The  introduction  and  universal  employment  of  the  potato  has  unquestionably  done  much 
to  correct  these  two  tendencies;  on  the  one  hand,  by  diluting  the  azotized  constituents  of 
the  food,  so  that,  with  the  same  bulk,  a  much  smaller  proportion  of  these  is  now  intro- 
duced ;  and  on  the  other,  by  supplying  to  the  blood  some  element  which  is  essential  to  the 
maintenance  of  its  healthy  condition.  But  with  the  diminution  of  the  arthritic  diathesis, 
which  the  experience  of  our  older  practitioners,  and  the  medical  writings  of  the  last  cen- 
tury, indicate  as  having  taken  place  during  that  period,  there  has  been  an  increase  in  the 
Rheumatic ;  —  a  change  which  seems  to  have  a  close  relation  to  this  alteration  in  diet. 
And  it  seems  not  improbable,  too,  that  this  alteration  in  diet  has  much  to  do  with  that 
diminished  power  of  sustaining  active  depletory  treatment,  which,  according  to  the  obser- 
vations of  practitioners  of  long  experience,  characterizes  the  present  generation  as  com- 
pared with  the  preceding.  But  whilst  there  is  a  diminished  capability  of  bearing  large 
blood-lettings,  violent  purgation,  &c.,  there  is  at  the  same  time  such  an  increased  tendency 
to  a  favourable  termination  in  many  of  those  diseases  for  which  they  were  formerly  ac- 
counted necessary,  as  should  remove  all  regret  at  this  change  of  constitution.  —  On  tho 
question  of  '  Vegetarianism,'  the  Author  may  refer  to  his  articles  on  that  subject  in  the 
"Brit,  and  For.  Med.  Chir.  Rev.,"  vol.  vi.  pp.  76  and  399. 


72  OF    FOOD,    AND   THE    DIGESTIVE    P110CESS. 

of  much  practical  importance  to  be  able  to  form  a  correct  average  estimate.  It 
is  from  the  experience  afforded  by  the  usual  consumption  of  food  by  large  bodies 
of  men,  that  our  data  are  obtained ;  and  these  data  are  sufficient  to  enable  us  to 
predict  with  tolerable  accuracy  what  will  be  required  by  similar  aggregations, 
though  they  can  afford  no  guide  to  the  consumption  of  individuals.  We  shall 
first  consider  the  quantity  sufficient  for  men  in  regular  active  exercise;  and  then 
inquire  how  far  that  may  be  safely  reduced  for  those  who  lead  a  more  sedentary 
life. —  The  Diet-scale  of  the  British  Navy  may  be  advantageously  taken  as  a  spe- 
cimen of  what  is  required  for  the  first  class.  It  is  well  known  that  an  extraor- 
dinary improvement  has  taken  place  in  the  health  of  seamen  during  the  last  80 
years ;  so  that  three  ships  can  now  be  kept  afloat,  with  only  the  same  number  of 
men  as  were  formerly  required  for  two.  This  is  due  to  the  improvement  of  the 
quality  of  the  food,  in  combination  with  other  prophylactic  means.  At  present, 
it  may  safely  be  affirmed  that  it  would  not  be  easy  to  construct  a  diet-scale  more 
adapted  to  answer  the  required  purpose.  The  health  of  crews  that  have  been 
long  afloat,  and  have  been  exposed  to  every  variety  of  external  conditions,  appears 
to  be  preserved  (at  least  when  they  are  under  the  direction  of  judicious  officers) 
to  the  full  as  well  as  that  of  persons  subject  to  similar  vicissitudes  on  shore ;  and 
there  can  be  no  complaint  of  insufficiency  of  food,  although  the  allowance  cannot 
be  regarded  as  superfluous.  It  consists  of  from  81  to  35^  ounces  of  dry  nutri- 
tious matter  daily;  of  this  26  oz.  are  vegetable,  and  the  rest  animal.  This  is 
found  to  be  amply  sufficient  for  the  support  of  strength ;  and  considerable  variety 
is  produced,  by  exchanging  various  parts  of  the  diet  for  other  articles.  This, 
however,  is  sometimes  done  erroneously ;  thus  8  oz.  of  fresh  vegetables,  which 
contain  only  1^  oz.  of  solid  nutriment,  are  exchanged  for  12  oz.  of  flour,  which 
is  almost  all  nutritious.  Sugar  and  Cocoa  are  also  allowed,  partly  in  exchange 
for  a  portion  of  the  spirits  formerly  served  out;  a  further  diminution  of  which 
has  recently  been  effected,  with  great  benefit. —  A  considerable  reduction  in  this 
amount  is  of  course  admissible,  where  little  bodily  exertion  is  required,  and 
where  there  is  less  exposure  to  low  temperatures.  In  the  case  of  prisoners,  the 
diet  should  of  course  be  as  spare  as  possible,  consistently  with  health ;  but  it 
should  be  carefully  modified,  in  individual  cases,  according  to  several  collateral 
circumstances,  such  as  depression  of  mind,  compulsory  labor,  previous  intempe- 
rate habits,  and  especially  the  length  of  confinement.  It  has  been  supposed  by 
some  that  prisoners  require  a  fuller  diet  than  persons  at  large  :  this  is  probably 
erroneous ;  but  more  variety  is  certainly  desirable,  to  counteract,  as  far  as  possi- 
ble, the  depressing  influence  of  their  condition  upon  the  digestive  powers.  The 
evil  effect  of  an  undue  reduction  in  the  supply  of  food,  and  of  insufficient  atten- 
tion to  its  quality,  has  unfortunately  been  too  frequently  displayed  in  our  prisons; 
a  notable  example  of  which  will  be  hereafter  alluded  to  (§  73).  A  very  excellent 
scale  of  dietaries,  adapted  to  the  different  conditions  of  Prison-life,  has  been 
issued  by  the  Government,  on  the  recommendation  of  the  Inspector  of  prisons. — 
The  effects  of  confinement  have  been  well  shown  in  the  experience  of  the  Edin- 
burgh House  of  Refuge,  which  was  first  established  in  1832,  for  the  reception  of 
beggars  during  the  Cholera,  and  which  has  been  continued  to  the  present  time. 
The  diet  was  at  first  a  quart  of  oatmeal  porridge  for  each  person,  morning  and 
evening ;  and  at  dinner  1  oz.  of  meat,  in  broth,  with  7  oz.  of  bread  :  making 
altogether  about  23  oz.  of  solid  food  per  day.  During  some  months  tbis  diet 
seemed  to  answer  very  well;  the  people  went  out  fatter  than  they  came  in,  owing 
to  the  diet  being  better  than  that  to  which  they  had  been  accustomed ;  but  after- 
wards a  proneness  to  disease  manifested  itself  in  those  who  had  been  residents  there 
for  a  considerable  time,  and  the  diet  was  therefore  somewhat  increased  with  good 
effect.  The  quantity  of  animal  food  was  probably  here  too  small ;  and  the  total 
weight  might  still  have  been  sufficient,  if  it  had  been  differently  apportioned. — 
The  inmates  of  Workhouses,  especially  those  who  have  been  accustomed  to  poor 
food  during  their  whole  lives,  require  much  less  than  those  more  actively  em- 


NATURE    AND    DESTINATION     OF    FOOD.  73 

ployed ;  and  it  is  of  importance  that  the  diet  should  not  be  superior  in  quantity 
or  quality,  to  that  which  the  labouring  classes  in  the  respective  neighbourhoods 
provide  for  themselves.  A  series  of  Diet-scales  for  Paupers  has  been  issued  by 
the  Poor-Law  Commissioners,  who  state  that  these  have  all  been  employed  in 
different  parts  of  England,  and  have  been  found  to  work  well  j  the  average  daily 
amount  of  solid  aliment  in  these  is  only  25^  oz. ;  and  of  this  not  above  18  oz. 
would  be  dry  nutriment.1  In  the  Edinburgh  workhouse,  of  which  the  inmates 
usually  have  good  health,  they  are  fed  upon  oatmeal  porridge  morning  and  even 
ing,  with  barley-broth  at  dinner ;  the  total  allowance  of  dry  nutriment  is  about 
17  oz. ;  namely,  13  oz.  of  vegetable,  and  4  oz.  of  animal.  In  the  Irish  Poor- 
houses,  notwithstanding  the  sufficiency  of  the  diet-scales,  which  are  more  liberal 
than  that  last  cited,  a  very  destructive  ophthalmia  has  prevailed  for  several  years 
past }  and  as  this  disease  is  scarcely  known  among  the  peasantry  at  large,  whose 
diet  is  certainly  not,  on  the  average,  better  than  that  of  the  inmates  of  the  poor- 
houses,  it  seems  probably  attributable  to  the  depressing  influence  of  the  monotony 
resulting  from  confinement,  which,  instead  of  being  antagonized  by  any  variation 
in  diet  from  day  to  day,  is  favoured  by  its  almost  entire  sameness. 

60.  The  smallest  quantity  of  food  upon  which  life  is  known  to  have  been  sup- 
ported with  vigour,  during  a  prolonged  period,  is  that  on  which  Cornaro  states 
himself  to  have  subsisted ;  this  was  no  more  than  12  oz.  a  day,  chiefly  of  vegeta- 
ble matter,  with  14  oz.  of  light  wine,  for  a  period  of  58  years.     There  is  another 
well-known  case  (that  of  Thomas  Wood,  the  miller  of  Billericay,  reported  to  the 
College  of  Physicians  in  1767,  by  Sir  George  Baker),  in  which  a  remarkable 
degree  of  vigour  was  sustained  for  upwards  of  eighteen  years,  upon  no  other 
nutriment  than  16  oz.  of  flour  (containing  about  14  oz.  of  dry  solids),  made  into 
a  pudding  with  water,  no  other  liquid  of  any  kind  being  taken.     There  are  pro- 
bably few,  however, — at  least  among  those  whose  avocations  require  much  mental 
or  bodily  exertion,  —  who  could  long  persevere  in  such  a  diet.     Still  it  is  certain 
that  life  with  a  moderate  amount  of  vigour  may  be  preserved  for  some  time,  on  a 
very  limited  allowance  of  food ;  this  appears  from  the  records  of  shipwreck  and 
similar  disasters.     In  regard,  however,  to  those  who  have  been  stated  to  fast  for 
a  period  of  months  or  even  years,  taking  no  nutriment,  but  maintaining  an  active 
condition,  it  may  be  safely  asserted  that  they  were  impostors,  probably  possessing 
unusual  powers  of  abstinence,  which  they  took  means  to  magnify  (§  76). 

61.  Of  the  quantity  which  can  be  devoured  at  one  time,  this  is  scarcely  the 
place  to  speak ;  since  such  feats  of  gluttony  only  demonstrate  the  extraordinary 
capacity  which  the  stomach  may  be  made  to  attain  by  continual  practice.     Many 
amusing  instances  are  related  by  Captain  Parry  in  his  Arctic  Voyages;  in  one 
case  a  young  Esquimaux,  to  whom  he  had  given  (for  the  sake  of  curiosity)  his 
full  tether,  devoured  in  four-and-twenty  hours  no  less  than  85  Ibs.  of  various 
kinds  of  aliment,  including  tallow-candles.     A  case  has  more  recently  been  pub- 
lished of  a  Hindoo,  who  can  eat  a  whole  sheep  at  a  time ;  this  probably  surpasses 
any  other  instance  on  record.     The  half-breed  voyagevrs  of  Canada,  according  to 
Sir  John  Franklin,  and  the  wandering  Cossacks  of  Siberia,  as  testified  by  Capt. 
Cochrane,  habitually  devour  a  quantity  of  animal  food  which  would  be  soon  fatal 
to  any  one  unused  to  it.     The  former  are  spoken  of  as  very  discontented  when 
put  on  a  short  allowance  of  8  Ibs.  of  meat  a  day;  their  usual  consumption  being 
from  12  to  20  Ibs. — That  a  much  larger  quantity  of  food  than  that  formerly  spe- 
cified may  be  habitually  taken,  with  perfect  freedom  from  injurious  consequences, 
under  a  particular  system  of  exercise,  &c.,  appears  from  the  experience  of  those 
who  are  trained  for  feats  of  strength,  pugilistic  encounters,  &c.     The  ordinary 
belief  that  the  Athletic  constitution  cannot  be  long  maintained,  appears  to  have 
no  real  foundation ;  nor  does  it  appear  that  any  ultimate  injury  results  from  the 
system  being  persevered  in  for  some  time.     That  <  trained '  men  often  fall  into 

1  A  copious  collection  of  Dietaries  will  be  found  in  Dr.  Pereira's  "Treatise  on  Food  and 
Diet,"  and  in  Dr.  Robertson's  "  Treatise  on  Diet  and  Regimen." 


74       OF  FOOD,  AND  THE  DIGESTIVE  PROG.  ESS. 

bad  health,  on  the  cessation  of  the  plan,  is  probably  owing  in  part  to  the  intem- 
perance and  other  bad  habits  of  persons  of  the  class  usually  subjected  to  tiny 
discipline.  The  effects  of  trainers'  regimen  are  hardness  and  firmness  of  the 
muscles,  clearness  of  the  skin,  capability  of  bearing  continued  severe  exercise, 
and  a  feeling  of  freedom  and  lightness  (or  'corkiness')  in  the  limbs.  During 
the  continuance  of  the  system,  it  is  found  that  the  body  recovers  with  wonderful 
facility  from  the  effects  of  injuries ;  wounds  heal  very  rapidly ;  cutaneous  erup- 
tions usually  disappear.  Clearness  and  vigour  of  mind,  also,  are  stated  to  be 
results  of  this  plan.1 

62.  It  is  not  enough  for  the  healthy  support  of  the  body  that,  the  Food  in- 
gested should  contain  an  adequate  proportion  of  alimentary  constituents;  it  is 
important  that  these  should  be  in  a  wholesome  or  undecom posing  state.  Putting 
out  of  view  all  impregnations  with  deleterious  substances  which  the  articles  used 
as  food  may  have  received  from  various  external  sources,  it  cannot  be  questioned 
that  they  may  derive  a  poisonous  character  from  changes  taking  place  in  their 
own  composition.  Thus  it  is  a  fact  very  familiar  to  German  Toxicologists,  that 
cheese,  bacon,  sausages,  and  other  articles,  may  spontaneously  undergo  such 
deleterious  alterations  as  give  rise,  when  they  are  employed  as  food,  to  all  the 
symptoms  of  irritant  poisoning,  which  may  even  pass  on  to  produce  fatal  conse- 
quences ;  that  such  occurrences  are  very  rare  in  this  country,  is  probably  to  be 
attributed  to  a  difference  in  the  mode  of  preparation.  This  change  does  not 
appear  to  consist  in  simple  putrescence ;  for  the  effects  which  the  cheese-poison, 
sausage-poison,  &c.,  produce  on  the  animal  economy,  are  far  more  potent  than 
mere  putrescence  could  occasion ;  and  it  is  supposed  by  Liebig  to  consist  in  the 
generation  of  a  peculiar  ferment,  which  the  stomach  is  not  able  to  decompose.2 

1  The  method  of  training  employed  by  Jackson  (a  celebrated  trainer  of  prize-fighters  in 
modern  times),  as  deduced  from  his  answers  to  questions  put  to  him  by  John  Bell,  was  to 
begin  on  a  clear  foundation  by  an  emetic  and  two  or  three  purges.  Beef  and  mutton,  the 
lean  of  fat  meat  being  preferred,  constituted  the  principal  food ;  veal,  lamb,  and  pork  were 
said  to  be  less  digestible  ("  the  last  purges  some  men").  Fish  was  said  to  be  a  "  watery 
kind  of  diet:"  and  is  employed  by  jockeys  who  wish  to  reduce  weight  by  sweating.  Stale 
bread  was  the  only  vegetable  food  allowed.  The  quantity  of  fluid  permitted  was  3J  pints 
per  diem;  but  fermented  liquors  were  strictly  forbidden.  Two  full  meals,  with  a  light 
supper,  were  usually  taken.  The  quantity  of  exercise  employed  was  very  considerable, 
and  such  as  few  men  of  ordinary  strength  could  endure.  —  This  account  corresponds  very 
much  with  that  which  Hunter  gave  of  the  North  American  Indians,  when  about  to  set  out 
for  a  long  march. 

a  [The  latest  investigations  on  the  subject  of  sausage  poison  are  those  of  Prof.  Julius 
Schlossberger  (Phil.  Med.  Exam.,  Feb.  1855),  who  thinks  it  best  to  discard  the  idea  of  a 
ferment,  as  its  nature  prevents  all  further  investigation,  and  in  place  thereof,  he  proposes 
his  supposition  as  applicable  to  most  of  the  cases,  and  which  has  already  been  strength- 
ened by  many  facts.  This  theory  attributes  the  action  of  many  poisonous  sausages  to  the 
presence  of  an  organic  base,  somewhat  similar  to  nicotine,  and  is  founded  upon,  1st,  the 
premises  already,  in  great  part,  established,  that  in  poisonous  sausages  and  cheese,  organic 
bases  are  formed  by  the  decomposition  of  the  protein  bodies;  and  2dly,  upon  the  previous 
supposition  that  they  give  rise  to  these  peculiar  symptoms  of  poisoning,  a  thought  that 
peems  already  to  have  occurred,  to  Kastner,  as  he  suggests  the  existence  of  an  alkaloid 
derived  from  the  mould  in  the  sausages.  The  presence  of  such  volatile  bases  in  the  de- 
composition of  nitrogenous  animal  substances,  from  which  ammonia  is  subsequently  formed, 
is  certainly  more  than  probable,  and  in  many  cases  stated  by  Stenhouse,  shown  to  be  con- 
stant. S.  has  also  found  ammonia  in  large  amount  in  the  noxious  sausages,  and  remarked, 
at  the  same  time,  a  peculiar,  disagreeable  odour.  The  behaviour  of  the  greater  part  of 
the  substances  homologous  with  ammonia,  in  the  organism,  is  still  unknown,  and  at  all 
events  each  of  them  requires  a  physiological  investigation ;  for  out  of  the  innumerable 
bases  that  have  been  and  will  yet  be  discovered,  many,  that  are  very  similar  in  compo- 
sition, exert  very  different  effects  upon  the  body.  On  the  other  hand,  nicotine,  coneine 
and  spartein  (the  three  best  known  representatives  of  the  volatile  bases  from  the  vegeta- 
ble kingdom,  and  whose  close  relation  with  ammonia  cannot  be  ignored)  are  well  known 
for  their  extraordinarily  poibonous  properties.  It  is  certain  that  alkaloids,  like  leucine  and 
tyrosine,  are  found  in  old  cheese,  and  if  these  harmless  substances  occur,  why  should  they 
not,  under  certain  circumstances,  be  accompanied  by  poisonous  bodies  possessing  the 


NAT  U  HE     AND     DESTINATION     OF    FOOD.  75 

Similar  changes  in  ordinary  flesh-meat  seem  to  be  sometimes  consequent  upon  the 
previous  existence  of  a  diseased  condition  in  the  animal  which  furnished  it. 
Many  instances  of  this  kind  have  been  recorded; '  —  and  the  risk  is  quite  suffi- 
cient to  justify  a  strict  prohibition  of  the  use  of  any  such  article.  —  That  meat 
which  is  simply  putrescent  is  to  be  considered  as  injurious  per  se,  when  habitu- 
ally employed,  is  scarcely  a  matter  of  reasonable  doubt.  It  is  true  that  some 
nations  are  in  the  habit  of  keeping  their  meat  until  it  is  tainted,  having  a  prefe- 
rence for  it  in  that  condition,  which  seems  to  have  grown  out  of  the  supposed 
necessity  for  thus  employing  it;  a  preference  which  has  its  parallel  among  the 
epicures  in  our  own  country,  who  consider  the  haut  gout  essential  to  the  perfec- 
tion of  their  venison  or  woodcock.  One  of  the  most  remarkable  examples  of  this 
kind  among  a  civilized  people,  is  furnished  by  the  inhabitants  of  the  Faroe 
islands ;  who,  according  to  the  report  of  Dr.  Panum,  who  has  investigated  their 
Sanitary  condition,  live  during  a  large  part  of  the  year  upon  meat  in  a  state  of 
incipient  decomposition,  and  introduce  rast,  or  half-decayed  maggotty  flesh,  fowl, 
or  fish,  as  a  special  relish  at  the  end  of  a  meal.2  The  result  of  such  a  diet  is  (as 
might  be  anticipated)  a  continual  disorder  of  the  digestive  organs,  manifesting 
itself  especially  by  diarrhoea.  This  is  a  symptom  of  annual  occurrence  on  the 
bird-islands,  and  is  also  invariably  observed  after  a  large  { take '  of  whales,  when 
much  of  the  flesh  of  these  animals  necessarily  becomes  'rast'  before  it  is  con- 
sumed. And  this  diarrhoea  also  complicates  the  course  of  other  diseases,  and 
even  becomes,  from  its  obstinacy  and  exhausting  character,  their  most  serious 
occurrence.  Moreover,  the  Fiiroese  are  peculiarly  liable  to  suffer  severely  from 
epidemics,  when  these  are  introduced  among  them ;  as  was  especially  shown  in 
the  epidemic  of  Measles  investigated  by  Dr.  Panum,  which  attacked  in  the 
course  of  six  months  scarcely  less  than  6000  out  of  a  population  of  7782,  no  age 
being  spared,  and  very  few  escaping  save  such  as  had  suffered  from  the  malady 
in  the  epidemic  which  had  occurred  65  years  previously,  and  such  as  maintained 
a  very  rigorous  isolation.  Hence,  notwithstanding  that  the  usual  rate  of  mortal- 
ity is  very  low  (only  1  in  64f  annually),  it  is  obvious  that  there  is  a  certain  con- 
stitutional condition  among  them,  which  peculiarly  favours  the  reception  and 
propagation  of  Zymotic  poisons;  and  it  is  quite  conformable  to  the  principles 

same  chemical  character?  S.  here  observes,  that  opium,  together  with  bases  that  act 
powerfully  upon  the  organism,  also  contains  alkaloids  that  are  perfectly  indifferent  in  this 
respect.  S.  also  cites  the  instance  of  the  volatile  bases  that  Wertheim  and  Hofmann  have 
shown  to  exist  in  herring  pickle  (propylamine,  trimethylamine).  S.  finally  endeavours  to 

make  use,  for  his  hypothesis,  of  the  circumstance  discovered  by  Kerner  and  A ,  that 

the  products  of  destructive  distillation  of  fresh  blood-sausages  cause  similar  symptoms  in 
animals  to  those  of  the  sausage  poisoning.  He  there  points  out  (according  to  Anderson's 
investigations  upon  the  pyrogenous  oil  from  bones)  that  during  the  destructive  distillation 
of  nitrogenous  bodies,  together  with  the  so-called  empyreumatic  bases,  the  alcohol  bases, 
such  as  methyl,  sethylamine,  &c.,  also  appear,  and  that  these  (like  the  separation  of  leucine 
into  valerianic  acid  and  ammonia)  form  the  necessary  steps,  in  place  of  the  fatty  acids  and 
ammonia.  S.  would  also  seek  for  the  same  volatile  bases  in  poisonous  mushrooms,  in 
ergot,  in  rotten  potatoes,  in  the  air  of  graves  and  cloacae,  and  even  in  the  so-called  cada- 
veric poison,  and  considers  them  as  the  cause  of  the  action  of  these  substances  upon  the 
organism.  —  ED.] 

1  See  "Ann.  d'Hygiene,"  1829,  ii.,  p.  267;  1834,  ii.,  69;  also  Taylor  in  "Guy's  Hos- 
pital Reports,"  April,  1843. 

a  See  Dr.  Panum's  'Observations  on  an  Epidemic  of  Measles  in  the  Faroe  Islands,'  in 
the  "  Bibliothek  for  Laogr.,"  1846;  of  which  an  analysis  is  given  in  the  "Brit,  and  For. 
Med.-Chir.  Rev.,"  vol.  vii.  p.  419. — Dr.  Panum  says,  "During  the  interval  of  many 
months  that  the  flesh,  fish,  or  fowl,  is  neither  fresh,  nor  yet  wind-dried,  it  is  called  '  rast,' 
.a  word  which.  I  can  only  translate  by  half-rotten.  This  appellation  it  fully  deserves,  from 
the  horrible  smell  that  it  sends  forth,  from  its  mouldy  aspect,  and  the  numerous  maggots 
that  swarm  upon  it.  1  have  seen  a  boat's  crew  of  eight  men  eating  with  great  relish  the 
raw  flesh  of  the  ca'aing  whale,  even  though  it  was  so  decomposed  that  the  smell  of  it  was 
disagreeable  to  me  even  in  an  open  boat,  and  the  bottom  of  the  boat  was  almost  white  with 
the  maggots  that  fell  from  the  decaying  mass." 


76       OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 

elsewhere  laid  down  (§  226),  to  attribute  this  to  the  habitual  introduction  of  pu- 
trescent  matter  with  the  food.  It  is  probable,  indeed,  that  if  it  were  not  for  the 
active  lives  of  the  Faroese,  and  their  habitual  exposure  to  a  low  external  tempera- 
ture, the  direct  effects  of  their  diet  would  be  far  more  prejudicial  than  they  are ; 
but  a  large  part  of  these  are  probably  neutralized  by  that  activity  of  respiration 
which  the  habits  of  life  of  this  hardy  people  induce,  much  of  the  noxious  mattei 
being  decomposed  and  eliminated  by  the  combustive  process  (§  232).  Hence  il 
may  well  be  conceived,  that  the  effects  of  putrescent  food  would  be  much  more 
decidedly  manifested  amongst  individuals  habitually  living  in  close,  ill-ventilated 
apartments;  and,  although  the  same  means  of  comparison  do  not  exist,  since 
there  is  no  part  of  our  town-population  habitually  subsisting  on  such  a  diet  a& 
that  of  the  Faroese,  yet  there  is  no  want  of  evidence  with  regard  to  the  injurious, 
effects  of  even  the  occasional  employment  of  putrescent  food,  especially  when  any 
zymotic  disease  is  epidemic.1 

63.  That  it  is  Water  which  constitutes  the  natural  drink  of  Man,  and  that  no 
other  liquid  can  supply  its  place,  is  apparent  from  the  most  cursory  glances  at  its 
uses  in  the  system ;  and  it  is  only  necessary  here  to  remark,  that  the  purity  of 
the  water  habitually  ingested  is  a  point  of  extreme  importance.  A  very  minute 
impregnation  with  lead,  for  example,  is  quite  sufficient  to  develope  all  the  symp- 
toms of  chronic  lead-poisoning,  if  the  use  of  such  water  be  sufficiently  prolonged. 
In  the  case  of  the  ex-royal  family  of  France,  many  of  whom  suffered  in  this 
manner  at  Claremont,2  the  amount  of  lead  was  only  about  one  grain  per  gallon  ; 
and  in  a  case  subsequently  published,  in  which  also  the  symptoms  of  lead-poison- 
ing were  unequivocally  developed,  the  amount  was  no  more  than  l-9th  of  a  grain.3 
So,  again,  an  excess  of  the  saline  ingredients,  which  appear  to  be  innocuous  in 
small  quantities,  may  produce  a  marked  disorder  of  the  digestive  organs,  and 
(through  them)  of  the  system  generally.4  Moreover,  as  in  the  case  of  food,  the 
presence  of  a  very  small  amount  of  putrescent  matter  is  quite  sufficient  to  pro- 
duce the  most  pernicious  results,  when  that  matter  is  habitually  introduced  into 
the  system ;  and  these  results,  on  the  one  hand,  manifest  themselves  in  the  pro- 
duction of  certain  disorders,  which  appear  distinctly  traceable  to  the  direct  action 
of  the  poison  so  introduced;  whilst,  on  the  other,  they  become  apparent  in  the 

1  Facts  of  this  kind  have  been  abundantly  furnished  during  the  visitations  of  Cholera.  See 
the  "  Report  of  the  General  Board  of  Health  on  the  Epidemic  Cholera  of  1848  and  1849," 
pp.  63,  64.  —  An  instance  of  a  very  remarkable  kind  occurred  at  Bridgwater,  towards  the 
close  of  that  epidemic,  as  related  to  the  author  by  Dr.  Brittan.  A  cargo  of  spoiled  oysters 
having  been  brought  to  the  town,  and  the  sale  of  them  having  been  prohibited  on  account 
of  their  putrescent  condition,  they  were  given  away  to  any  who  would  receive  them  ;  and 
several  children  in  a  neighbouring  school  partook  of  them  plentifully.  In  the  course  of  the 
following  night,  all  who  had  eaten  of  the  oysters  (so  far  as  Dr.  Brittan  could  ascertain) 
were  attacked  with  cholera  and  choleraic  diarrhoea,  and  eleven  of  the  children  died  the 
next  day. 

"  See  the  account  of  this  case,  which  presents  many  features  of  great  interest,  in  the 
"Dublin  Quarterly  Journal  of  Medical  Science,"  vol.  vii.  p.  415. 

3  See  Herapath  in  "  Medical  Gazette,"  Sept.  20,  1850,  p.  518. 

4  Of  this  a  very  instructive  case,  which  occurred  at  Wolverton,  has  been  published  t  v 
Mr.  Corfe  in  the  "Pharmaceutical  Journal,"  July,   1848.     So  large  a  number  of  indi- 
viduals were  there  attacked,  after  the  use  of  water  from  a  certain  well  for  some  months, 
with  disorders  bearing  a  strong  general  resemblance  to  each  other,  though  differing  in  their 
subordinate  features,  and  the  intensity  of  these  disorders  bore  such  a  constant  ratio  to  the 
amount  of  the  saline  water  habitually  employed,  that  no  reasonable  doubt  could  exist 
with  respect  to  its  causative  agency.     Yet  the  total  quantity  of  saline  matter  was  only 
about  40  grains  per  gallon,  or  but  little  more  than  one-sixth  of  that  which  is  contained  in 
the  Marienbad  water,  the  spa  to  which  it  presented  the  greatest  resemblance  in  the  com- 
bination of  its  components ;  and  as  the  symptoms  which  were  prevalent  at  Wolverton  bore 
A  very  close  correspondence  with  those  which  are  known  to  result  from  the  imprudent  use 
of  the  Marienbad  water,  it  appears  that  here  too  the  same  effects  are  produced  by  the  long- 
continued  employment  of  the  weaker  beverage,  as  by  a  much  smaller  number  of  doses  of 
the  stronger  one. 


EFFECTS    OF    ALCOHOLIC    DRINKS.  77 

extraordinary  augmentation  of  the  liability  to  attacks  of  such  zymotic  diseases  as 
may  at  the  time  be  prevalent.1 

64  The  various  beverages  employed  by  Man,  for  the  most  part  consist  of 
Water  holding  solid  matters  of  different  kinds  in  solution ;  and  it  is  not  requi- 
site, therefore,  to  bestow  any  special  attention  upon  them.  But  the  use  of  Alcohol, 
in  combination  with  water  and  with  organic  and  saline  compounds,  in  the  various 
forms  of  '  fermented  liquors/  deserves  particular  notice,  on  account  of  the  nu- 
merous fallacies  which  are  in  vogue  respecting  it.  —  In  the  first  place,  it  may  be 
safely  affirmed  that  Alcohol  cannot  answer  any  one  of  those  important  purposes 
for  which  the  use  of  Water  is  required  in  the  system ;  and  that,  on  the  other 
hand,  it  tends  to  antagonize  many  of  those  purposes,  by  its  power  of  precipitating 
most  of  the  organic  compounds,  whose  solution  in  water  is  essential  to  their  appro- 
priation by  the  living  body.  Secondly,  the  ingestion  of  Alcoholic  liquors  cannot 
supply  anything  which  is  essential  to  the  due  nutrition  of  the  system ;  since  we 
find  not  only  individuals,  but  whole  nations,  maintaining  the  highest  vigour  and 
activity,  both  of  body  and  mind,  without  ever  employing  them  as  an  article  of 
diet.  Thirdly,  there  is  no  reason  to  believe  that  Alcohol,  in  any  of  its  forms, 
can  become  directly  subservient  to  the  Nutrition  of  the  tissues ;  for  it  may  be 
certainly  affirmed  that,  in  common  with  non-azotized  substances  in  general,  it  is 
incapable  of  transformation  into  Albuminous  compounds;  and  there  is  no  suffi- 
cient evidence,  that  even  Fatty  matters  can  be  generated  in  the  body  at  its  ex- 
pense.2 Fourthly,  the  alimentary  value  of  Alcohol  consists  merely  in  its  power 
of  contributing  to  the  production  of  Heat,  by  affording  a  pabulum  for  the  respi- 
ratory process;  but  for  this  purpose  it  would  be  pronounced  on  Chemical  grounds 
alone  to  be  inferior  to  fat  (§  54);  and  the  result  of  the  experience  of  Arctic 
voyagers  and  travellers  is  most  decided  in  regard  to  the  comparatively  low  value 
of  Alcohol  as  a  heat-producing  material.  —  Fifthly,  the  operation  of  Alcohol  upon 
the  living  body  is  essentially  that  of  a  stimulus;  increasing  for  a  time,  like  other 
stimuli,  the  vital  activity  of  the  body,  and  especially  that  of  the  nervo-muscular 
apparatus,  so  that  a  greater  effect  may  often  be  produced  in  a  given  time  under 
its  use,  than  can  be  obtained  without  it ;  but  being  followed  by  a  corresponding 
depression  of  power,  which  is  the  more  prolonged  and  severe,  in  proportion  as  the 
previous  excitement  has  been  greater.  Nothing,  therefore,  is  in  the  end  gained 
by  their  use;  which  is  only  justifiable  where  some  temporary  emergency  can  only 
be  met  by  a  temporary  augmentation  of  power,  even  at  the  expense  of  an  in- 
creased amount  of  subsequent  depression ;  or  where  (as  in  the  case  of  some  indi- 
viduals whose  digestive  power  is  deficient)  it  affords  aid  in  the  introduction  of 

1  For  ample  evidence  to  this  effect,  see  Dr.  Pereira's  "  Treatise  on  Food  and  Diet," 
pp.  89-91 ;  and  the  "Report  of  the  General  Board  of  Health  on  the  Epidemic  Cholera  of 
1848  and  1849,"  pp.  59-63,  "  Appendix  A,"  p.  14,  and  "Appendix  B,"  pp.  91-95.  —  The 
foil-owing  very  instructive  case  occurred  a  few  years  ago,  within  the  Author's  own  know- 
ledge. In  a  certain  terrace,  in  the  most  aristocratic  suburb  of  a  large  provincial  town, 
consisting  of  houses  of  a  superior  class,  and  very  favourably  situated  as  regards  the  access 
of  pure  air,  an  epidemic  of  gastric  fever  broke  out,  much  to  the  astonishment  and  dismay 
of  the  residents,  no  such  malady  having  ever  been  known  to  prevail  in  the  neighbourhood. 
It  was  soon  observed,  however,  that  the  attacks  of  the  fever  were  limited  (in  the  first  in- 
stance at  least)  to  those  individuals  who  were  accustomed  to  use  the  water  of  a  neighboar- 
ing  well;  those  who  were  supplied  from  a  deep  spring  at  a  distance  being  entirely  free, 
For  some  little  time  before  this  outbreak,  a  disagreeable  taste  had  been  observed  in  the 
well-water;  and  this  was  subsequently  traced  to  the  bursting  of  a  sewer,  which  had  dis- 
charged part  of  its  contents  into  the  well.  This  cause  being  removed,  the  terrace  has 
since  exhibited  no  tendency  whatever  to  a  recurrence  of  the  effect. 

'2  It  is  quite  true  that  some  persons  who  consume  large  quantities  of  fermented  liquors 
become  very  fat ;  but  the  material  for  this  fat  is  probably  derived  in  part  from  the  consti- 
tuents of  the  food,  and  in  part  from  the  disintegration  of  the  tissues ;  the  hydrocarbona- 
ceous  matters  in  the  system  being  prevented  from  undergoing  the  combustive  process  to 
which  they  would  otherwise  be  subject,  by  the  superior  affinity  for  oxygen  which  Alcohol 
possesses.  Much  of  the  fatty  deposit  in  intemperate  persons  has  the  character  of  'fatty 
degeneration  ; '  the  tendency  to  which  is  very  marked  in  persons  of  this  class. 


78  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

aliment  into  the  system,  which  nothing  else  can  so  well  supply.  These  excep- 
tional cases,  however,  will  be  less  numerous,  in  proportion  as  due  attention  is 
paid  to  those  other  means  of  promoting  health,  which  are  nmre  in  accordance 
with  Nature. 

65.  The  Physiological  objections  to  the  habitual  use  of  even  small  quantities 
of  Alcoholic  liquors,  rest  upon  the  following  grounds.  First,  they  are  univer- 
sally admitted  to  possess  a  poisonous  character,  when  administered  in  large  doses; 
death  being  the  speedy  result,  through  the  suspension  of  nervous  power,  which 
their  introduction  into  the  circulation  in  sufficient  quantity  is  certain  to  induce. — 
Secondly,  when  habitually  used  in  excessive  quantities,  universal  experience 
shows  that  Alcoholic  liquors  tend  to  produce  a  morbid  condition  of  the  body  .at 
large,  and  especially  of  the  nervous  system  ;  this  condition  being  such  as  a  know- 
ledge of  its  modus  operandi  on  the  body  would  lead  the  Physiologist  to  predi- 
cate. —  Thirdly,  the  frequent  occurrence  of  more  chronic  diseases  of  the  same 
character,  among  persons  advanced  in  life,  who  have  habitually  made  use  of  Alco- 
holic liquors  in  'moderate7  amount,  affords  a  strong  probability  that  they  result 
from  a  gradual  perversion  of  the  nutritive  processes,  of  which  that  habit  is  the 
cause.  This  perversion  manifests  itself  peculiarly  in  the  tendency  to  l  fatty  dege- 
neration' of  the  muscular  substance  of  the  heart,  of  the  walls  of  the  arteries,  of 
the  glandular  substance  of  the  kidney  and  liver,  and  of  many  other  parts ;  and 
thus  gives  rise  to  a  great  variety  of  forms  of  disease.  It  seems  probable  that  its 
modus  operandi  in  these  cases,  is  not  so  much  by  directly  deteriorating  the  forma- 
tive operations,  as  by  obstructing  the  removal  of  the  bydrocarbonaceous  products 
of  the  continual  disintegration  of  the  tissues,  in  virtue  of  the  stronger  affinity 
which  alcohol  has  for  oxygen,  whereby  it  will  prevent  the  Respiratory  process 
from  exerting  its  due  influence  in  the  purification  of  the  blood.  —  Fourthly,  the 
special  liability  of  the  intemperate  to  zymotic  diseases,  seems  an  indication  that 
the  habitual  irigestion  of  Alcoholic  liquors  tends  to  prevent  the  due  elimination 
of  the  azotized  products  of  the  disintegration  of  the  system,  and  thus  to  induce  a 
'  fermentable'  condition  of  the  blood  (§  226).  —  Fifthly,  extended  experience  has 
shown  that  notwithstanding  the  temporary  augmentation  of  power  which  may 
result  from  the  occasional  use  of  fermented  liquors,  the  capacity  for  prolonged 
endurance  of  mental  or  bodily  labour,  and  for  resisting  the  extremes  of  heat  and 
cold,  as  well  as  other  depressing  agencies,  is  diminished  rather  than  increased  by 
their  habitual  employment.  —  On  these  grounds,  the  Author  has  felt  himself  fully 
justified  in  the  conclusion,  that,  for  Physiological  reasons  alone,  habitual  absti- 
nence from  Alcoholic  liquors  is  the  best  rule  that  can  be  laid  down  for  the  great 
majority  of  healthy  individuals ;  the  exceptional  cases  in  which  any  real  benefit 
can  be  derived  from  their  use,  being  extremely  few.1  [In  addition  to  the  mate- 
rials of  food  already  enumerated  may  be  mentioned  a  class  of  articles  which, 
although  not  absolutely  essential  to  life,  are  instinctively  demanded  by  man j 
these  are  Tea  and  Coffee,  Pepper,  Tobacco,  Spices,  Opium,  Indian  Hemp.  These 
have  been  called  by  Dr.  T.  K.  Chambers,  EXTRA  DIET,  or  ACCESSORY  FOOD.* 
They  are  what  Man  does  not  want,  if  the  protracting  his  existence  on  earth  from 
day  to  day,  be  the  sole  end  of  his  feeding.  He  could  live  without  them,  grow 
without  them,  think  without  them ;  and  yet  we  find  among  all  classes  a  craving 
for  them  which  is  with  some  irresistible.  Of  the  effects  of  Tea  and  Coffee  as 
articles  of  Diet  we  have  the  evidence  of  Dr.  Booker,  detailed  in  a  Tract  (Re- 
searches on  the  Action  of  Tea),  containing  the  results  of  experiments  upon  him- 
self with  that  article.  The  first  set  of  the  first  series  consists  of  seven  observa- 
tions, of  twenty-four  hours  duration  each,  in  the  months  of  July  and  August,  with 

1  See  his  "  Physiology  of  Temperance  and  Total  Abstinence ;  "  also  the  important  Trea- 
tise on  "Alcoholismus  Chronicus  "  by  Dr.  Huss  of  Stockholm,  of  which  an  abstract  is  givei, 
in  the  "  Brit,  and  For.  Med.  Chir.  Rev.,"  vols.  vii.  and  ix. 

"Brit,  and  For.  Mod.  Chir.  Rev.,"  Oct.,  1854,  on  the  use  of  Alcohol,  T^s),  Coffee,  and 
other  accessory  Food. 


EFFECTS    OF    ALCOHOLIC     DRINKS.  79 

three  barely  sufficient  meals  per  diem,  in  quantities  as  nearly  equal  each  day  as 
could  be  managed,  and  with  only  spring-water  to  drink.  The  second  set  comprise 
the  same  number  of  observations  in  August,  September  and  October,  under  simi- 
lar circumstances,  except  that  infusion  of  tea,  drunk  cold,  was  taken  instead  of 
plain  water.  A  careful  record  was  made  each  day  of  the  quantity  of  urine,  and 
feeces,  and  of  the  water  and  solid  matters  contained  therein,  with  their  reaction, 
colour,  &c.,  the  amount  of  insensible  perspiration,  carbonic  acid  expired,  number 
of  respiratory  movements,  pulse,  and  the  duration  of  bodily  exercise  in  the  open 
air,  and  every  circumstance  in  short  that  could  in  any  way  influence  the  result. 
A  third  series  of  experiments  of  similar  character  was  instituted,  and  the  follow- 
ing conclusions  were  arrived  at  as  a  deduction  from  the  whole. 

1.  Tea  in  ordinary  doses  has  not  any  effect  on  the  amount  of  carbonic  acid 
expired,  the  frequency  of  respiration,  or  the  pulse. 

2.  When  the  Diet  is  insufficient,  Tea  limits  very  much  the  loss  of  weight 
thereby  entailed. 

3.  When  the  Diet  is  insufficient,  the  body  is  more  likely  to  gain  weight  when 
Tea  is  taken,  than  when  not. 

4.  Tea  diminishes  very  much  the  loss  of  substance  in  the  shape  of  Urea. 

5.  It  lessens  remarkably  the  quantity  of  fasces  excreted. 

6.  The  loss  by  perspiration  is  also  limited  by  Tea. 

A  series  of  experiments  made  by  Dr.  Julius  Lehmann,  exhibits  the  effects  of 
Coffee  on  the  urinary  excretion;  the  results  are  as  follows : 

1.  "That  Coffee  produces  on  the  organism  two  chief  effects,  which  it  is  very 
difficult  to  connect  together,  viz. :  the  raising  the  activity  of  the  vascular  and 
nervous  systems,  and  protracting  remarkably  the  decomposition  of  the  tissues. 

2.  "  That  it  is  the  reciprocal  modifications  of  the  specific  actions  of  the  euipy- 
reumatic  oil  and  caffein  contained  in  the  bean  which  call  forth  the  stimulant 
effects  of  Coffee,  and  therefore  those  peculiarities  of  it  which  possess  importance 
in  our  eyes,  viz.  :  the  rousing  into  new  life  the  soul  prostrated  by  exertion,  and 
especially  the  giving  it  greater  elasticity,  and  attuning  it  to  meditation,  and  pro- 
ducing a  general  feeling  of  comfort  and  cheerfulness. 

3.  "That  the  protraction  of  metamorphic  decomposition  which  this  beverage 
produces  in  the  body  is  chiefly  caused  by  the  empyreumatic  oil,  and  that  the 
caffein  only  causes  it  when  it  is  taken  in  larger  quantity  than  usual. 

4.  "  That  caffein  (in  excess)  produces  increased  action  of  the  heart,  rigors,  de- 
rangement of  the  urinary  organs,  headache,  a  peculiar  inebriation,  delirium,  &c. 

5.  "That  the  empyreumatic  oil  (in  excess)  causes  perspiration  and  diuresis, 
quickened  motion  of  the  bowels,  and  augmented  activity  of  the  understanding, 
which  may  indeed,  by  an  increase  of  the  dose,  end  in  irregular  trains  of  thought 
and  congestions,  restlessness  and  incapacity  for  sleep." 

These  observations  would  seem  to  show  that  the  Tea  and  Coffee-drinkor  may 
have  less  to  eat,  and  yet  lose  less  weight  than  the  Water-drinker.  And  that 
under  circumstances  where  Animal  Food  is  scarce,  they  may  diminish  the  demand 
for  it  by  lessening  the  waste  of  the  nitrogonized  tissues  by  the  use  of  these  beve- 
rages. The  observations  of  M.  Gasparin  show  that  the  journeymen  miners  in 
the  neighbourhood  of  Charleroi  preserve  robust  health  and  great  muscular  strength 
by  the  habitual  use  of  Coffee,  which  enters  largely  into  their  daily  food.  Their 
meals  consist  of  Bread  and  Butter  and  Coffee,  with  some  green  Vegetables.  Meat 
is  eaten  but  once  a  week.  It  is  calculated  that  such  a  labourer  consumes  only 
about  four  drachms  of  nitrogen  a  day,  an  amount  greatly  less  than  that  required 
in  other  places  and  under  other  circumstances. 

The  observations  of  Dr.  Booker  on  the  use  of  Alcohol  go  to  show  that  it  also 
diminishes  the  waste  of  tissues;  the  results  following  the  administration  of  a 
teaspoonful  of  Alcohol  seven  or  eight  times  a  day  being  thus : 

1.  Alcohol  diminishes  the  excretion  both  of  the  solid  and  fluid  constituents  of 
the  urine. 


80  OF    FOOD,     AND     THE    DIGESTIVE    PROCESS. 

2.  Alcohol  does  not  increase  the  cutaneous  perspiration. 

3.  Alcohol  does  not  augment  the  faecal  excretion. 

4.  Alcohol  diminishes  not  only  the  absolute  quantity  of  carbonic  acid  exhaled 
by  the  lungs,  but  also  the  relative  proportion  of  it  in  the  products  of  respiration. 

5.  The  excretion  of  Water  by  the  lungs  is  unaffected. 

The  therapeutical  deductions  that  follow  from  the  above  Physiological  observa- 
tions in  the  administration  of  Tea,  Coffee  and  Alcohol,  are,  that  when  waste  is  to 
be  prevented,  the  nervous  energy  roused  and  the  circulation  invigorated,  each 
may,  by  their  cautious  administration,  be  rendered  normal.  When  it  is  desir-  4 
able  that  secretion  should  take  place  more  actively,  destructive  absorption  be 
encouraged,  or  the  circulation  be  moderated,  abstinence  from  them  should  be 
enjoined. 

A  series  of  carefully  conducted  experiments  with  the  various  narcotics  will 
probably  show  that  they  too  exercise  a  controlling  power  over  the  waste  of  the 
tissues.  It  requires  more  than  the  mere  fleeting  enjoyment  of  their  effects  to 
account  for  the  instinctive  longing  which  even  the  most  barbarous  nations  mani- 
fest for  their  use.  —  ED.] 

2.    Of  Hunger  and  Thirst;  —  Starvation. 

66.  The  want  of  solid  aliment,  arising  out  of  the  several  sources  of  demand 
formerly  enumerated  (§§  26-28),  is  indicated  by  the  sensation  of  Hunger;  and 
that  of  liquid,  by  Thirst.     The   former  of  these  sensations  is  referred  to  the 
stomach,  and  the  latter  to  the  fauces ;  but  although  certain  conditions  of  these 
parts  may  be  the  immediate  cause  of  the  sensations  in  question,  they  are  really 
indicative  of  the  requirements  of  the  system  at  large.     For  the  intensity  of  the 
feeling  bears  no  constant  relation  to  the  amount  of  solid  or  liquid  aliment  in  the 
stomach ;  whilst  on  the  other  hand,  it  does  correspond  with  the  excess  of  demand 
in  the  system,  over  the  supply  afforded  by  the  blood;  and  it  is  caused  to  abate 
by  the  introduction  of  the  requisite  material  into  the  circulating  fluid,  even  though 
this  be  not  accomplished  in  the  usual  manner  by  the  ingestion  of  food  or  drink 
into  the  stomach. 

67.  That  the  sense  of  Hunger,  however,  is  immediately  dependent  upon  some 
condition  of  the  Stomach,  seems  to  follow  from  the  fact,  that  it  may  be  tempo- 
rarily alleviated,  by  introducing  into  the  digestive  cavity  matter  which   is  not 
alimentary.     Of  the  precise  nature  of  that  condition,  we  have  no  certain  know- 
ledge.    It  is  easy  to  prove  that  many  of  the  causes  which  have  been  assigned  for 
the  sensation  are  but  little,  if  at  all,  concerned  in  producing  it.     Thus  mere 
emptiness  of  the  Stomach  cannot  occasion  it ;  since,  if  the  previous  meal  have 
been  ample,  the  food  passes  from  its  cavity  some  time  before  the  uneasy  feeling* 
is  renewed ;  and  this  emptiness  may  continue  (in  certain  disordered  states  of  the 
system)  for  many  hours  or  even  days,  without  a  return  of  desire  for  food.    Besides, 
the  stomach  may  be  filled  with  food,  and  yet  Hunger  may  be  intensely  felt  if,  from 
disease  of  the  pylorus  or  any  other  cause,  there  be  an  obstacle  to  the  passage  of 
the  aliment  into  the  intestine,  and  to  the  completion  of  the  processes  of  chylifi- 
cation  and  absorption,  so  that  the  system  needs  that  which  the  digestive  apparatus 
is  unable  to  provide  for  it.     Again,  the  sense  of  Hunger  cannot  be  due,  as  some 
have  supposed,  to  the  action  of  the  gastric  fluid  upon  the  coats  of  the  stomach 
themselves ;  since  this  fluid  is  not  poured  into  the  stomach,  except  when  its  pro- 
duction is  stimulated  by  the  irritation  of  the  secreting  follicles.     It  is  thought  by 
Dr.  Beaumont,  that  the  distension  of  these  follicles  with  the  secreted  fluid  is  the 
proximate  cause  of  hunger;  but  there  is  no  more  reason  to  believe  that  the 
secretion  of  gastric  fluid  is  accumulated  during  the  intervals  when  it  is  not  re- 
quired, than  there  is  in  regard  to  saliva,  the  lachrymal  fluid,  or  any  other  secre- 
tions, which  are  occasionally  poured  out  in  large  quantities  under  the  influence 
of  a  particular  stimulus;  and,  moreover,  it  is  difficult  to  imagine  how  mental 


OF    HUNGER    AND    THIRST — STARVATION.  81 

emotion,  or  any  impression  on  the  nervous  system  alone  (which  is  able,  as  is  well 
known,  to  dissipate  the  keenest  appetite  in  a  moment),  can  relieve  such  disten- 
sion.—  It  may,  perhaps,  be  a  more  probable  supposition,  that  there  is  a  certain 
condition  of  the  Capillary  circulation  in  the  Stomach,  which  is  preparatory  to  the 
secretion,  and  which  is  excited  by  the  influence  of  the  Sympathetic  nerves,  that 
communicate  (as  it  were)  the  wants  of  the  general  system.  This  condition  may 
be  easily  imagined  to  be  the  proximate  cause  of  the  sensation  of  hunger,  by  act- 
ing on  the  nervous  centres.1  When  food  is  introduced  into  the  stomach,  the  act 
of  secretion  is  directly  excited  j  the  capillary  vessels  are  gradually  unloaded ;  and 
the  immediate  cause  of  the  impression  on  the  nervous  system  is  withdrawn.2  By 
the  conversion  of  the  alimentary  matter  into  materials  fit  for  the  nutrition  of  the 
system,  the  remote  demand  also  is  satisfied ;  and  thus  it  is  that  the  condition  of 
the  stomach  just  referred  to  is  permanently  relieved  by  the  ingestion  of  substances 
that  can  serve  as  food.  But  if  the  ingested  matter  be  not  of  a  kind  capable  of 
solution  and  assimilation,  or  the  digestive  apparatus  cannot  effect  its  preparation, 
the  feeling  of  hunger  is  only  temporarily  relieved,  and  soon  returns  in  greater 
force  than  before.  —  The  theory  here  given  seems  reconcilable  with  all  that  has 
been  said  of  the  conditions  of  the  sense  of  Hunger ;  and  particularly  with  what 
is  known  of  the  effect  produced  upon  it  by  nervous  impressions,  which  have  a 
peculiar  influence  upon  the  capillary  circulation.  It  also  corresponds  exactly  with 
what  we  know  of  the  influence  of  the  nervous  system,  and  of  mental  impressions, 
upon  other  secretions  (CHAP.  xv.). 

68.  The  sense  of  Hunger,  like  other  sensations,  may  not  be  taken  cognizance 
of  by  the  Mind,  if  its  attention  be  strongly  directed  towards  other  objects ;  of 
this  fact,  almost  every  one  engaged  in  active  operations,  whether  mentally  or 
bodily,  is  occasionally  conscious.  The  nocturnal  student,  who  takes  a  light  and 
early  evening  meal,  and,  after  devoting  himself  to  his  pursuits  for  several  hours 
uninterruptedly,  retires  to  rest  with  a  wearied  head  and  an  empty  stomach,  but 
without  the  least  sensation  of  hunger,  is  frequently  prevented  from  sleeping  by 
an  indescribable  feeling  of  restlessness  and  deficiency;  and  the  introduction  of  a 
small  quantity  of  food  into  the  stomach  will  almost  instantaneously  allay  this,  and 
procure  comfortable  rest.  Many  persons,  again,  who  desire  to  take  active  exercise 
before  breakfast,  are  prevented  from  doing  so  by  the  lassitude  and  even  faintness 
which  it  induces,  —  the  bodily  exercise  increasing  the  demand  for  food,  whilst  it 
draws  off  the  attention  from  the  sensation  of  hunger.3 

1  It  was  maintained  by  Brachet,  that  the  senses  of  Hunger  and  Satiety  are  annihilated 
by  section  ef  the  Pneumogastric  nerves ;  which,  if  true,  would  strongly  confirm  the  view 
that  the  immediate  source  of  these  senses  lies  in  the  condition  of  the  Stomach.  But  the 
researches  of  other  experimenters,  particularly  those  of  Dr.  John  Reid  ("Edinb.  Med.  and 
Surg.  Journ.,"  April,  1839,  and  "Physiological,  Anatomical,  and  Pathological  Researches," 
pp.  234-239),  do  not  confirm  this  view;  for  they  seem  to  show  that  after  the  immediate 
effect  of  the  operation  has  subsided,  animals  take  food  with  no  less  avidity  than  previously. 
It  appears,  however,  from  Dr.  Reid's  observations,  as  well  as  from  those  of  Valentin,  that 
the  sense  of  Satiety  is  more  dependent  upon  the  continuity  of  these  nerves,  than  is  that  of 
Hunger ;  for  animals  on  whom  the  section  of  the  Pneumogastric  has  been  performed,  do 
not  seem  to  know  when  they  have  had  enough,  but  continue  to  gorge  themselves  with  food 
long  after  the  stomach  has  been  adequately  filled. 

a  These  views  seem  to  be  confirmed  by  the  observations  of  M.  Bernard  on  the  condition 
of  the  gastric  follicles  during  the  intervals  of  their  functional  activity  ($  94). 

9  The  Author  may  be  excused  for  mentioning  the  following  circumstance,  which  some 
years  ago  occurred  to  himself;  and  which  seems  to  him  a  good  illustration  of  the  principle, 
that  the  sense  of  hunger  originates  in  the  condition  of  the  general  system,  and  that  its 
manifestation,  through  a  peculiar  action  in  the  stomach,  is  to  be  regarded  as  a  secondary 
phenomenon  —  adapted,  under  ordinary  circumstances,  to  arouse  the  mind  to  the  actions 
necessary  for  the  supply  of  the  physical  wants,  —  but  capable  of  being  overlooked,  if  the 
attention  of  the  mind  be  otherwise  directed.  He  was  walking  alone  through  a  beautiful 
country,  and  with  much  to  occupy  his  mind;  and,  having  expected  to  meet  with  some 
opportunity  of  obtaining  refreshment  on  his  road,  he  had  taken  no  food  since  his  break- 
fast. This  expectation,  however,  was  not  fulfilled ;  but,  as  he  felt  no  hunger,  he  thought 
6 


82  OF    FOOD,     AND    THE    DIGESTIVE     PROCESS. 

69.  The  conditions  of  the  sense  of  Thirst  appear  to  be  very  analogous  to  those 
of  hunger.    This  sense  is  not  referred,  however,  to  the  stomach,  but  to  the  fauces 
It  is  generally  considered  that  it  immediately  results  from  an  impression  on  the 
nerves  of  the  stomach  ;  since,  if  liquids  are  introduced  into  the  stomach  through 
an  oesophagus-tube,  they  are  just  as  effectual  in  allaying  thirst  as  they  are  if  swal- 
lowed in  the  ordinary  manner.     It  may  be  doubted,  however,  whether  the  sense 
of  thirst  is  not  even  more  immediately  connected  with  the  state  of  the  general 
system,  than  that  of  hunger;  for  the  immediate  relief  afforded  by  the  introduc- 
tion of  liquid  into  the  stomach,  is  fully  accounted  for  by  the  instantaneous  ab- 
sorption of  the  fluid  into  the  veins,  which  is  known  to  take  place  when  there  is 
a  demand  for  it,  not  only  from  Dr.  Beaumont's  observations,  but  from  many 
experiments  made  with  reference  to  this  particular  question.     This  demand  is 
increased  with  almost  equal  rapidity,  by  an  excess  in  the  amount  of  the  fluid 
excretions ;  and  it  may  be  satisfied,  or  at  least  alleviated,  without  the  introduction 
of  water  into  the  stomach,  this  having  been  one  of  the  results  observed  after  the 
use  of  saline  injections  into  the  veins  in  cases  of  Asiatic  Cholera,  as  well  as  after 
immersion  in  a  warm  bath  in  cases  of  extreme  dysphagia.     Thirst  may  also  be 
produced,  however,  by  the  impression  made  by  peculiar  kinds  of  food  or  drink 
upon  the  walls  of  the  alimentary  canal ;  thus  salted  or  highly-spiced  meat,  fer- 
mented liquors  when  too  little  diluted,  and  other  similarly  irritating  agents,  excite 
thirst ;  the  purpose  of  which  is  obviously  to  cause  ingestion  of  fluid,  by  which  they 
may  be  diluted. 

70.  The  results  of  an  entire  deficiency  of  Food,  or  of  its  supply  in  a  measure 
inadequate  for  the  wants  of  the  system,  constitute  the  phenomena  of  Inanition 
or  Starvation.     These  have  been  experimentally  studied  by  M.  Chossat1  on  Birds 
and  Mammals;  and  the  information  thence  gained  leads  us  to  a  better  compre- 
hension of  what  is  (unfortunately)  too  frequently  exhibited  in  the  Human  sub- 
ject. —  The  following  were  the  general  symptoms  noted  by  M.  Chossat.     The 
animals  usually  remain  calm  during  the  first  half  or  two-thirds  of  the  period , 
but  they  then  become  more  or  less  agitated ;  and  this  state  continues  as  long  as 
their  temperature  remains  elevated.     On  the  last  day  of  life,  however,  whilst  the 
temperature  rapidly  falls,  this  restlessness  ceases,  and  gives  place  to  a  state  of 
stupor.     The  animal,  when  set  at  liberty,  sometimes  looks  round  with  astonish- 
ment, without  attempting  to  fly ;  and  sometimes  closes  the  eyes,  as  if  in  a  state 
of  sleep.     Gradually  the  extremities  become  cold,  and  the  limbs  so  weak  as  no 
longer  to  be  able  to  sustain  the  animal  in  a  standing  posture ;  it  falls  over  on  one 
side,  and  remains  in  any  position  in  which  it  may  be  placed,  without  attempting 
to  move.     The  respiration  becomes  slower  and  slower;  the  general  weakness  in- 
creases, and  the  insensibility  becomes  more  profound ;  the  pupil  dilates ;  and  life 
becomes  extinct,  sometimes  in  a  calm  and  tranquil  manner,  sometimes  after  con- 
vulsive actions,  producing  opisthotonic  rigidity  of  the  body.     After  the  first  day, 
in  which  the  faeces  contain  the  residue  of  the  food  previously  taken,  their  amount 
is  very  small ;  and  they  seem  to  consist  principally  of  grass-green  biliary  matter. 
Towards  the  close  of  life,  they  contain  a  much  larger  quantity  of  water,  even 
when  none  has  been  ingested  by  the  animal ;  and  include  much  saline  matter  in 
addition  to  the  biliary. —  The  average  loss  of  weight  in  the  warm-blooded  animals 
experimented  on  by  M.  Chossat,  between  the  commencement  of  the  period  of 

little  of  the  disappointment.  It  was  evening  before  he  approached  the  place  of  his  desti- 
nation, after  having  walked  about  twenty  miles,  resting  frequently  by  the  way ;  and  he 
then  began  to  feel  a  peculiar  lassitude,  different  from  ordinary  fatigue,  which  rapidly  in- 
creased, so  that  during  the  last  mile  he  could  scarcely  support  himself.  The  "stimulus 
of  necessity,"  however,  kept  him  up;  but  on  arriving  at  his  temporary  home,  ho  imme- 
diately fainted.  It  is  obvious  that,  in  this  case,  the  occupation  of  the  mind  on  the  objects 
around,  and  on  its  own  thoughts,  had  prevented  the  usual  warning  of  hunger  from  being 
perceived;  and  the  effect  which  succeeded  was  exactly  what  was  to  be  anticipated,  from 
the  exhaustion  of  the  supply  of  food  occasioned  by  the  active  and  prolonged  exertion. 
1  "  Recherches  Experimentales  sur  PInanition,"  Paris,  1843. 


OF    HUNGER    AND    THIRST  —  STARVATION. 


83 


Inanition  and  its  termination  by  death,  was  40  per  cent;  but  he  met  with  a 
considerable  variation  in  the  extremes,  which  seemed  to  depend  chiefly  on  the 
amount  of  fat  previously  accumulated  in  the  body;  those  animals  losing  most 
weight  in  which  the  fat  had  been  most  abundant,  which  were  also  those  that 
lived  the  longest.1  Taking  40  per  cent  as  the  mean,  M.  Chossat  obtained  the 
following  curious  results,  as  regards  the  relative  diminution  of  the  several  tissues 
and  organs  of  the  body;  those  which  lost  more  than  the  mean,  being  distin- 
guished from  those  which  lost  less. 


Parts  which  lose  more  than  40  per  cent. 

Fat 93-3 

Blood 75-0 

Spleen 71-4 

Pancreas 64-1 

Liver 52-0 

Heart 44-8 

Intestines 42-4 

Muscles  of  Locomotion 42-3 


Parts  which  lose  less  than  40  per  cent. 

Muscular  coat  of  stomach 39-7 

Pharynx  and  oasophagus 34-2 

Skin 33-3 

Kidneys 31-9 

Respiratory  apparatus 22-2 

Osseous  system 16-7 

Eyes 10-0 

Nervous  system 1-9 


The  points  most  worthy  of  note  in  the  above  table,  are  the  almost  complete 
removal  of  the  fat,  and  the  reduction  of  the  blood  to  three-fourths  its  normal 
amount;  whilst  the  nervous  system  undergoes  scarcely  any  loss.  It  would  seem, 
in  fact,  as  if  the  supervention  of  death  was  coincident  with  the  consumption  of 
all  the  disposable  combustive  material ;  and  that  up  to  that  point,  the  whole  re- 
maining energy  of  nutrition  is  concentrated  upon  the  nervous  system.  And  it 
will  be  shown  hereafter  (CHAP,  x.,  Sect.  2),  that  there  is  adequate  ground  for 
considering  death  by  starvation  as  really  death  by  cold;  since  the  temperature  of 
the  body  is  maintained  with  little  diminution  until  the  fat  is  thus  consumed,  and 
then  rapidly  falls,  unless  it  be  kept  up  by  heat  externally  applied. —  As  might  be 
expected  from  the  comparative  rapidity  of  interstitial  change  at  the  earlier  periods 
of  life  (CHAP,  xviil.),  it  was  found  by  Chossat  that  the  diurnal  loss  was  much 
the  most  rapid  in  young  animals,  and  that  the  duration  of  their  lives  when 
deprived  of  food  was  consequently  far  less  than  that  of  adults.  He  further 
ascertained  that  the  results  of  insufficient  alimentation  were  in  the  end  the  same 
as  those  of  entire  deprivation  of  food;  the  total  amount  of  loss  being  almost 
exactly  identical,  but  its  rate  being  less,  so  that  a  longer  time  was  required  to 
produce  it.  He  did  not  find  that  much  influence  was  exerted  on  the  duration 
of  life,  by  permitting  or  withdrawing  the  supply  of  water;  but  this  statement 
does  not  apply  to  Man,  in  whom  death  supervenes  much  earlier  when  liquid  as 
well  as  solid  aliment  is  withheld ;  and  the  indifference  in  the  case  of  Birds  is 
probably  due  to  the  fact  that  they  ordinarily  drink  very  sparingly,  and  eliminate 
very  little  water  in  their  various  excretions. 

71.  The  most  prominent  symptoms  of  Starvation,  as  they  have  been  noted  in 
the  Human  subject,  are  as  follows  :  —  In  the  first  place,  severe  pain  in  the  epigas- 
trium, which  is  relieved  on  pressure ;  this  subsides  after  a  day  or  two,  but  is  suc- 
ceeded by  a  feeling  of  weakness  and  t sinking'  in  the  same  region;  and  an  insa- 
tiable thirst  supervenes,  which,  if  water  be  withheld,  thenceforth  becomes  the 
most  distressing  symptom.  The  countenance  becomes  pale  and  cadaverous ;  the 
eyes  acquire  a  peculiar  wild  and  glistening  stare ;  and  general  emaciation  soon 
manifests  itself.  The  body  then  exhales  a  peculiar  footer,  and  the  skin  is  covered 
with  a  brownish,  dirty-looking,  and  offensive  secretion.  The  bodily  strength 
rapidly  declines ;  the  sufferer  totters  in  walking,  his  voice  becomes  weak,  and  he 

1  There  is  a  well-known  case  of  a  fat  pig,  which  was  buried  in  its  sty  for  160  days, 
under  thirty  feet  of  the  chalk  of  Dover  cliff;  and  which  was  dug  out  alive  at  the  end  of 
lhat  time,  reduced  in  weight  from  160  Ibs.  to  40  Ibs.,  or  no  less  than  75  per  cent. 
("Trans,  of  Linn  Soc.,"  vol.  xi.  p.  411).  The  extraordinary  prolongation  of  life  in 
this  case  may  be  attributed  to  the  retention  of  the  heat  of  the  body  by  the  non-conducting 
power  of  the  chalk ;  and  to  the  retention  of  its  moisture  by  the  saturation  of  the  air  in  its 
immediate  vicinity. 


84  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

is  incapable  of  the  least  exertion.  The  mental  powers  exhibit  a  similar  prostra- 
tion ;  at  first  there  is  usually  a  state  of  stupidity,  which  gradually  increases  to 
imbecility,  so  that  it  is  difficult  to  induce  the  sufferer  to  make  any  effort  for  his 
own  benefit ;  and  on  this  a  state  of  maniacal  delirium  frequently  supervenes.  Life 
terminates  either  in  the  mode  described  in  Chossat's  observations,  or,  as  occa- 
sionally happens,  in  a  convulsive  paroxysm.1  —  On  post-mortem  examination,  the 
condition  of  the  body  is  found  to  be  such  as  the  results  of  Chossat's  observations 
would  indicate;  namely,  extreme  general  emaciation  and  disappearance  of  fat, 
diminution  in  the  bulk  of  the  principal  viscera,  and  almost  complete  bloodlessness, » 
save  in  the  brain,  which  still  receives  its  usual  supply.  It  is  specially  worthy  of 
note,  that  the  coats  of  the  small  intestines  are  peculiarly  thinned,  so  that  they  be- 
come almost  transparent;  and  that  the  gall-bladder  is  almost  invariably  turgid 
with  bile,  the  cadaveric  exudation  of  which  tinges  the  surrounding  parts.  And 
further,  the  body  rapidly  passes  into  decomposition. 

72.  Now  it  is  peculiarly  worthy  of  note,  that  the  deficient  supply  of  new  histo- 
genetic  materials  appears  to  check  the  elimination  and  removal  of  those  which 
have  become  effete ;  for  in  no  other  way  can  we  account  for  that  tendency  to 
putrescence,  which  is  so  remarkably  manifested  during  life  in  the  foetid  exhala- 
tion and  in  the  peculiar  secretion  from  the  skin,  and  which  is  shown  after  death 
in  the  rapidity  with  which  putrefaction  supervenes.     Moreover,  towards  the  close 
of  many  exhausting  diseases,  the  fatal  termination  of  which  is  really  due  to  a 
chronic  inanition,  it  frequently  happens  that  a  '  colliquative  diarrhoea'  comes  on, 
which  must  be  considered  as  a  manifestation  of  the  general  disintegration  that 
is  making  progress  even  during  life.  —  Now  referring  to  the  conditions  hereafter 
to  be  enumerated  (§  226),  as  those  which  favour  the  operation  of  zymotic  poisons 
in  the  body,  it  is  obvious  that  no  state  could  be  more  liable  to  it  than  this;  since 
we  have  not  merely  that  general  depression  of  the  vital  powers,  which  is  a  predis- 
posing cause  of  almost  any  kind  of  malady,  and  pre-eminently  so  of  zymotic 
diseases ;  but  also  the  presence  of  a  large  amount  of  disintegrating  matter  in  the 
blood  and  general  system,  which  forms  the  most  favourable  nidus  possible  for  the 
reception  and  multiplication  of  such  poisons.     And  thus  it  happens  that  pestilen- 
tial diseases  most  certainly  follow  in  the  wake  of  a  famine,  and  carry  off  a  far 
greater  number  than  perish  from  actual  starvation. 

73.  Another  class  of  phenomena,  however,  results  from  such  a  deficiency  of 
alimentation  as  is  not  adequate  to  produce  the  results  just  described;  provided 
this  deficiency  be  prolonged  for  a  considerable  length  of  time,  and  especially  if  it 
be  conjoined  with  other  unfavourable  conditions.     Of  this,  a  remarkable  example 
was  presented  at  the  Milbank  Penitentiary  in  1823.     The  prisoners  confined  in 
this  establishment,  who  had  previously  received  an  allowance  of  from  31  to  33 
oz.  of  dry  nutriment  daily,  had  this  allowance  suddenly  reduced  to  21  oz.,  animal 
food  being  almost  entirely  excluded  from  the  diet  scale.     They  were  at  the  same 
time  subjected  to  a  low  grade  of  temperature,  and  to  considerable  exertion ;  and 
were  confined  within  the  walls  of  a  prison  situated  in  the  midst  of  a  marsh  which 
is  below  the  level  of  the  adjoining  river.     The  prison  had  been  previously  con- 
sidered healthy;  but  in  the  course  of  a  few  months,  the  health  of  a  large  propor- 
tion of  the  inmates  began  to  give  way.     The  first  symptoms  were  loss  of  colour, 
and  diminution  of  flesh  and   strength;   subsequently  diarrhoea,  dysentery,  and 
scurvy ;  and  lastly  adynamic  fevers,  or  headache,  vertigo,  convulsions,  maniacal 
delirium,  apoplexy,  &c.     The  smallest  loss  of  blood  produced  syncope,  which  was 
frequently  fatal :  and  after  death,  ulceration  of  the  mucous  lining  of  the  alimen- 
tary canal  was  very  commonly  found.     Out  of  860  prisoners,  no  fewer  than  437, 
or  52  per  cent,  were  thus  affected.     The  influence  of  concurrent  conditions,  espe- 
cially of  previous  confinement,  was  here  remarkably  shown ;  for  those  were  found 
to  be  most  liable  to  disease,  who  had  been  in  prison  the  longest.    That  the  reduc- 

1  See  Rostan  in  "Diction,  de  Me'decine,"  art.  'Abstinence;'  and  Dr.  Donovan's  account 
of  the  Irish  famine  of  1847,  in  the  "  Dublin  Medical  Press,"  Feb.,  1848. 


OF    HUNGER    AND    THIRST  —  STARVATION.  85 

tion  of  the  allowance  of  food,  however,  was  the  main  source  of  the  epidemic,  was 
proved  by  the  two  following  facts  :  —  the  prisoners  employed  in  the  kitchen,  who 
had  8  oz.  of  bread  additional  per  day,  were  not  attacked,  except  three  who  had 
only  been  there  a  few  days :  and  after  the  epidemic  had  spread  to  a  great  extent, 
it  was  found  that  the  addition  of  8  oz.  to  the  daily  allowance  of  vegetable  food, 
and  £  oz.  to  the  animal,  greatly  facilitated  the  operation  of  the  remedies  which 
were  used  for  the  restoration  of  health.1  —  Another  very  striking  example  of  the 
effects  of  prolonged  insufficiency  of  diet,  has  been  furnished  by  the  *  Maison  Cen- 
trale'  of  Nimes;  which  is  a  large  Penitentiary  containing  an  average  of  1200 
prisoners.  The  mortality  in  this  prison,  between  the  years  1829  and  1847,  varied 
from  1  in  7'85  to  1  in  23-88,  the  average  being  1  in  12-70;  whilst  the  average 
mortality  among  the  inhabitants  of  the  town  of  Nimes,  of  the  same  age  and  sex, 
was  only  1  in  49-9;  so  that  the  mortality  among  the  prisoners  was  from  two  to 
six  times  as  great  as  that  among  the  townspeople,  the  average  being  nearly  four 
times.  Several  causes  doubtless  concurred  to  produce  this  terrible  result ;  but 
whilst  over-crowding  and  deficient  ventilation  were  constant,  deficiency  of  food, 
amount  of  labour  exacted,  and  depression  of  temperature  were  variable  ;  and  the 
variations  in  the  amount  of  mortality  followed  these  last  so  uniformly,  that  there 
could  be  no  doubt  of  their  dependence  upon  them.2 

74.  It  is  a  curious  effect  of  insufficient  nutriment,  as  shown  by  the  inquiries 
of  Chossat  (Op.  cit.),  that  it  produces  an  incapability  of  digesting  even  the  small 
amount  consumed.     He  found  that  when  turtle-doves  were  supplied  with  limited 
quantities  of  corn,  but  with  water  at  discretion,  the  whole  amount  of  food  taken 
was  scarcely  ever  actually  digested ;  a  part  of  it  being  rejected  by  vomiting,  or 
passing  off  by  diarrhoea,  or  accumulating  in  the  crop.     It  seems  as  if  the  vital 
powers  were  not  sufficient  to  furnish  the  requisite  supply  of  gastric  fluid,  when 
the  body  began  to  be  enfeebled  by  insufficient  nutrition ;  or  perhaps  we  might 
well  say,  the  materials  of  the  gastric  fluid  were  wanting.  —  Hence  the  loathing 
of  food,  which  is  often  manifested  by  those  who  have  been  subjected  to  the  in- 
fluence of  an  insufficient  diet  scale  in  our  prisons  and  poor-houses,  and  which  has 
been  set  down  to  caprice  or  obstinacy,  and  punished  accordingly,  may  be  actually 
a  proof  of  the  deficiency  of  the  supply,  which  we  might  expect  to  have  been 
voraciously  devoured,  if  really  less  than  the  wants  of  the  system  require. 

75.  It  is  extremely  important  that  the  Medical  Practitioner  should  be  aware, 
that  many  of  the  phenomena  above  described  may  be  induced  by  the  adoption  of 
a  system  of  too  rigid  abstinence  in  the  treatment  of  various  diseases;  and  that 
they  have  been  frequently  confounded  with  the  symptoms  of  the  malady  itself, 
and  have  led  to  an  entirely  erroneous  method  of  treating  it.    "  Many  cases,"  says 
Dr.  Copland,3  "  have  occurred  to  me  in  practice,  where  the  antiphlogistic  regi- 
men, which  had  been  too  rigidly  pursued,  was  itself  the  cause  of  the  very  symp- 
toms which  it  was  employed  to  remove.     Of  these  symptoms,  the  affection  of  the 
head  and  delirium  are  the  most  remarkable,  and  the  most  readily  mistaken  for  an 
actual  disease  requiring  abstinence  for  its  removal."  —  The  experience  of  those 
especially,  who  are  largely  engaged  in  consulting  practice,  must  have  furnished 
numerous  illustrations  of  the  above  statement.     Dr.  Copland  mentions  the  fol- 
lowing.    "A  professional  man  had  been  seized  with  fever,  for  which  a  too  rigid 
abstinence  was  enforced,  not  only  during  its  continuance,  but  also  during  con- 
valescence.    Delirium  had  been  present  at  the  height  of  the  fever,  and  recurred 
when  the  patient  was  convalescent.     A  physician  of  eminence  in  maniacal  cases 
was  called  to  him,  and  recommended  that  he  should  be  removed  to  a  private 
asylum.     Before  this  was  carried  into  effect,  I  was  requested  to  see  him.     A  dif- 

1  See  Dr.  Latham  '•  On  the  Diseases  in  the  Milbank  Penitentiary  ;"  1824. 
*  See  the  highly  instructive  account  of  this  series  of  occurrences,  by  M.  Boileau-Castel- 
nau,  chief  physician  to  the  '  Maison  Centrale,'  in  "Ann.  d'Hygiene  Publ.,"  Janv.,  1849. 
8  "Dictionary  of  Practical  Medicine,"  vol.  i.  p.  26. 


86  OF    FOOD,    AND    THE    DIGESTIVE     PROCESS. 

ferent  treatment  and  regimen,  with  a  gradual  increase  of  nourishment,  wore 
adopted ;  and  he  was  well  in  a  few  days,  and  within  a  fortnight  returned  to  his 
professional  avocations." 

76.  The  time  during  which  life  can  be  supported  under  entire  abstinence  from 
food  or  drink,  is  usually  stated  to  vary  from  8  to  10  days ; l  the  period  may  be 
greatly  prolonged,  however,  by  the  occasional  use  of  water,  and  still  more  by  a 
very  small  supply  of  food  :  or  even,  it  would  seem,  by  a  moist  condition  of  the 
surrounding  atmosphere,  which  obstructs  the  exhalation  of  liquid  from  the  body. 
Thus  Fodere  mentions  that  some  workmen  were  extricated  alive,  after  fourteen 
days'  confinement  in  a  cold  damp  vault,  in  which  they  had  been  buried  under  a 
ruin.     Dr.  Sloan  has  given  an  account2  of  the  case  of  a  healthy  man,  set.  65,  who 
was  found  alive  after  having  been  shut  up  in  a  coal-mine  for  twenty-three  days, 
during  the  first  ten  of  which  he  was  able  to  procure  and  swallow  a  small  quantity 
of  foul  water;  he  was  in  a  state  of  extreme  exhaustion,  and  died  three  days  after- 
wards, notwithstanding  the  attempts  made  to  recover  him.  —  It  would  seem  as  if 
certain  conditions  of  the  Nervous  system,  especially  those  attended  with  peculiar 
emotional  excitement,  are  favourable  to  the  prolongation  of  life  under  such  cir- 
cumstances.    Thus,  in  a  case  recorded  by  Dr.  Willan,  of  a  young  gentleman  who 
starved  himself  under  the  influence  of  a  religious  delusion,  life  was  prolonged  for 
60  days ;  during  the  whole  of  which  time,  nothing  else  was  taken  than  a  little 
orange-juice.     In  a  somewhat  similar  case  which  occurred  under  the  Author's 
notice,  in  the  person  of  a  young  French  lady,  more  than  15  days  elapsed  between 
the  time  that  she  ceased  to  eat  regularly,  and  the  time  of  her  being  compelled  to 
receive  nourishment;  during  this  period  she  took  a  good  deal  of  exercise,  and 
her  strength  seemed  to  suffer  but  little,  although  she  swallowed  solid  food  only 
once,  and  then  in  small  quantity.     Again,  in  certain  states  of  the  system  com- 
monly known  as  'hysterical/  there  is  frequently  a  very  remarkable  disposition 
for  abstinence,  and  power  of  sustaining  it.    In  a  case  of  this  kind  which  occurred 
under  the  Author's  own  observation,  a  young  lady,  who  had  just  before  suffered 
severely  from  the  tetanic  form  of  Hysteria,  was  unable  to  take  food  for  three 
weeks.     The  slightest  attempt  to  introduce  a  morsel  of  solid  matter  into  the 
stomach,  occasioned  violent  efforts  at  vomiting ;  and  the  only  nourishment  taken 
during  the  period  mentioned,  was  a  cup  of  tea  once  or  twice  a  day;  and  on  many 
days  not  even  this  was  swallowed.     Yet  the  strength  of  the  patient  rather  in- 
creased than  diminished  during  this  period ;  her  muscles  became  firmer,  and  her 
voice  more  powerful.  —  It  may  be  well  to  remark  that,  under  such  circumstances, 
the  continual  persuasions  of  anxious  friends  are  very  injurious  to  the  patient; 
whose  return  to  her  usual  state  will  probably  take  place  the  earlier,  the  more 
completely  she  is  left  to  herself. 

3.  Movements  of  the.  Alimentary  Canal. 

77.  The  motions  by  which  Food  is  conveyed  to  the  Mouth  and  introduced  into 
its  cavity,  constituting  the  acts  of  Prehension  and  Ingestion,  are  ordinarily  con- 
sidered to  be  voluntary,  at  least  in  the  adult;  and  it  is  indub  table  that  the  Will 
has  entire  control  over  them.     Nevertheless,  they  belong  to  that  class  of  '  second- 
arily automatic '  movements,  whose  character  has  been  already  noticed  (§45); 
and,  like  the  movements  of  locomotion,  may  be  liept  up  when  the  will  is  in  abey- 
ance, by  the  suggesting  and  guiding  influence  of  sensations,  thus  being  performed 
under  the  same  essential  conditions  as  the  purely  'consensual'  or  sensori-motor' 

1  There  seems  adequate  evidence,  that  a  state  which  may  be  characterized  as  one  of  Syn- 
cope, —  the  animal  functions  being  entirely  suspended,  and  the  organic  functions  being 
reduced  to  an  extremely  low  ebb,  —  may  be  prolonged  for  many  days  or  even  weeks,  pro- 
vided the  temperature  of  the  body  be  not  too  much  reduced.  This  class  of  facts,  however, 
will  be  more  appropriately  considered  hereafter  (CHAP.  xix.). 

'  "  Medical  Gazette,"  vol.  xvii.  p.  389. 


MOVEMENTS    OF    THE    ALIMENTARY    CANAL  —  MASTICATION.  87 

notions.1  The  necessity  of  ' guiding  sensations'  for  their  performance  is  made 
evident  by  one  of  Sir  G.  Bell's  experiments,  the  wrong  interpretation  of  whose 
results  originally  led  him  to  an  erroneous  view  of  the  functions  of  the  Fifth  pair 
of  nerves.  He  found  that  an  Ass,  in  which  the  infra-orbital  branch  of  this 
nerve  had  been  divided,  made  no  attempt  to  pick  up  oats  with  its  lip,  although 
the  animal  saw  them,  bent  down  its  head  with  the  obvious  purpose  of  ingesting 
them,  and  brought  its  lip  into  absolute  contact  with  them  j  hence  he  concluded 
that  the  power  of  motion  was  destroyed  in  the  lip,  when  it  was  in  reality  only  the 
guiding  sensation  that  was  deficient,  the  motor  power  being  supplied  by  the  Facial 
nerve  or  Portio  dura.  —  But,  although  the  movements  concerned  in  the  ingestion 
of  food  in  the  adult  require  the  co-operation  of  the  sensorial  centres,  this  is  not 
the  case  with  the  act  of  suction  in  the  Infant,  which  may  be  considered  as  essen- 
tially a  respiratory  act,  and  which  is  performed  not  merely  without  ivill,  but  even 
without  consciousness.  The  experiments  provided  for  us  by  Nature,  in  the  pro- 
duction of  anencephalous  monstrosities,  fully  prove  that  the  '  nervous  circle* 
whereby  the  lips  and  respiratory  organs  are  connected  with  the  Medulla  Oblon- 
gata,  is  alone  sufficient  for  its  performance;  and  Mr.  Grainger  has  sufficiently 
established  the  same,  by  experimenting  upon  puppies  whose  brain  had  been  re- 
moved. He  adds  that,  as  one  of  these  brainless  puppies  lay  on  its  side,  sucking 
the  finger  which  was  presented  to  its  lips,  it  pushed  out  its  feet  in  the  same 
manner  as  young  pigs  exert  theirs  against  the  sow's  dugs.2  The  Human  Infant 
or  other  young  Mammal,  however,  performs  movements  which  are  of  a  higher 
character  than  this ;  going  in  search,  as  it  were,  of  the  source  of  its  nourishment, 
towards  which  it  seems  to  be  especially  guided  by  the  sense  of  Smell.  Such 
movements  are  probably  to  be  considered  as  '  consensual/  and  as  deriving  their 
first  stimulus  from  the  internal  feelings  of  hunger,  whilst  their  direction  is  given 
by  the  guiding  sensation  which  indicates  the  situation  of  the  appropriate  aliment. 
That  no  such  actions  are  called  into  play  by  the  same  stimuli,  after  the  expiration 
of  the  period  during  which  the  young  Mammal  is  dependent  upon  its  maternal 
parent  for  its  nourishment,  seems  to  indicate  that  the  reactive  power  of  the  ner- 
vous centres  to  which  they  are  due  is  only  temporary,  and  that  it  ceases  with  the 
need  foi  its  exercise ;  the  child  growing  out  (so  to  speak)  of  this  automatic  power, 
whilst  it  grows  into  many  new  ones, —  those  especially  which  are  connected  with 
the  generative  function. 

78.  The  food  thus  introduced  into  the  mouth  is  subjected  (unless  it  be  already 
in  a  state  which  needs  no  further  reduction)  to  the  process  of  Mastication.  This 
is  evidently  an  operation  of  great  importance,  in  preparing  the  substances  to  be 
afterwards  operated  on,  for  the  action  of  their  solvent ;  and  it  exactly  corresponds 
with  the  trituration  to  which  the  Chemist  would  submit  any  solid  matter,  that  he 
might  present  it  in  the  most  advantageous  form  to  a  digestive  menstruum.  The 
complete  disintegration  of  the  alimentary  matter  is,  therefore,  of  great  conse- 

1  This,  the  Author  thinks,  will  be  conformable  to  the  experience  of  most  of  his  readers ; 
who  will  find,  if  they  analyze  their  own  consciousness,  that  they  continue  to  eat  while  their 
whole  attention  is  given  to  some  abstract  train  of  thought,  or  to  some  external  object.  But 
a  remarkable  case  will  be  cited  hereafter  (CHAP.  XL,  Sect.  6),  which  fully  confirms  the 
view  here  advanced ;  the  movements,  not  merely  of  the  lips  and  jaws,  but  those  by  which 
food  was  conveyed  to  the  mouth,  having  been  carried  on  automatically,  when  once  (so  to 
speak)  the  spring  was  touched  by  which  they  were  set  in  action. 

3  "Observations  on  the  Structure  and  Functions  of  the  Spinal  Cord,"  pp.  80,  81. — 
The  actions  of  the  mammary  foetus  of  the  Kangaroo,  described  by  Mr.  Morgan,  furnish  a 
very  intaresting  exemplification  of  the  same  function  of  the  Spinal  Cord ;  this  creature, 
resembling  an  earth-worm  in  appearance,  and  only  about  fourteen  lines  in  length,  with  a 
brain  corresponding  in  degree  of  development  to  that  of  a  human  -foetus  of  the  ninth  week, 
executes  regular,  but  slow,  movements  of  respiration,  adheres  firmly  to  the  point  of  the 
nipple,  and  moves  its  limbs  when  disturbed.  The  milk  is  forced  into  the  oesophagus  by 
a  compressor  muscle,  with  which  the  mamma  of  the  parent  is  provided,  "  Can  it  be 
imagined,"  very  justly  asks  Mr.  Grainger,  "that  in  this  case  there  are  sensation  and 
volition,  in  what  can  be  proved  anatomically  to  be  a  foetus  ?" 


88 


OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 


quence;    and,   if   imperfectly  effected,   the   subsequent    processes  are  liable  to 
derangement.      Such    derangement   we   continually   meet    with ;    for   there   ia 


[FlG.  11. 


49 


A  view  of  the  Organs  of  Digestion,  opened  in  nearly  their  whole  length;  a  portion  of 
the  oesophagus  has  been  removed  on  account  of  want  of  space  in  the  figure;  the  arrows 
indicate  the  course  of  substances  along  the  canal :  1,  the  upper  lip,  turned  off  the  mouth ; 
2,  its  fraenum;  3,  the  lower  lip,  turned  down;  4,  its  fraenum ;  5,  5,  inside  of  the  cheeks, 
covered  by  the  lining  membrane  of  the  mouth ;  6,  points  to  the  opening  of  the  duct  of 
Steno;  7,  roof  of  the  mouth;  8,  lateral  half-arches;  9,  points  to  the  tonsil;  10,  velum 
pendulum  palati;  11,  surface  of  the  tongue;  12,  papillae  near  its  point;  13,  a  portion  of 
the  trachea;  14,  the  oesophagus;  15,  its  internal  surface;  16,  inside  of  the  stomach;  17, 
its  greater  extremity  or  great  cul-de-sac;  18,  its  lesser  extremity  or  smaller  cul-de-sac; 
19,  its  lesser  curvature ;  20,  its  greater  curvature ;  21,  the  cardiac  orifice ;  22,  the  pyloric 
orifice;  23,  upper  portion  of  duodenum;  24,  25,  the  remainder  of  the  duodenum;  26,  its 
valvulae  connivences;  27,  the  gall-bladder;  28,  the  cystic  duct;  29,  division  of  hepatic 
ducts  in  the  liver;  30,  hepatic  duct;  31,  ductus  communis  choledochus;  32,  its  opening 
into  the  duodenum ;  33,  ductus  Wirsungii,  or  pancreatic  duct;  34,  its  opening  into  the  duo- 
denum ;  35,  upper  part  of  jejunum  ;  36,  the  ileum ;  37,  some  of  the  valvulae  conniventes ; 
38,  lower  extremity  of  the  ileum;  39,  ileo-colic  valve;  40,  41,  coecum,  or  «aput  coli;  42, 
appendicula  vermiformis  ;  43,  44,  ascending  colon  ;  45,  transverse  colon  ;  46,  47,  descend- 
ing colon;  48,  sigmoid  flexure  of  the  colon;  49,  upper  portion  of  the  rectum;  50,  its 
lower  extremity ;  51,  portion  of  the  levator-ani  muscle ;  52,  the  anus.] 


MOVEMENTS    OF   THE   ALIMENTARY   CANAL  —  MASTICATION.  89 

not.  perhaps,  a  more  frequent  source  of  Dyspepsia  than  imperfect  mastication, 
whether  resulting  from  the  haste  with  which  the  food  is  swallowed,  or  from  the 
want  of  the  instruments  proper  for  the  reducing  operation.  The  mechanical 
disintegration  of  the  food  is  manifestly  aided  by  Insalivation ;  but  the  admixture 
of  Saliva  also  exerts,  as  we  shall  hereafter  see  (§  93),  a  very  marked  influence  on 
the  chemical  composition  of  certain  of  its  constituents. —  The  movements  of  Mas- 
tication, still  more  than  those  already  adverted  to,  although  under  the  complete 
control  of  the  Will,  and  originally  dependent  upon  it  for  their  excitation,  come 
at  last  to  be  of  so  habitual  a  character  that  they  continue  when  the  direct  influ- 
ence of  the  will  is  withdrawn,  the  influence  of  the  l  guiding  sensation/  however, 
being  essential  to  their  performance.1  Every  one  is  conscious  that  the  act  of 
mastication  may  be  performed  as  well  when  the  mind  is  attentively  dwelling  on 
some  other  object,  as  when  directed  to  it;  but;  in  the  former  case,  we  are  rather 

[Fio.  12. 


12 

A  view  of  the  Muscles  of  the  Tongue,  Palate,  Larynx  and  Pharynx  —as  well  as  the 
position  of  the  upper  portion  of  the  Oesophagus,  as  shown  by  a  vertical  section  of  the 
head;  1,  1,  the  vertical  section  of  the  head;  2,  points  to  the  spinal  canal;  3,  section  of 
the  hard  palate;  4,  inferior  spongy  bone;  5,  middle  spongy  bone;  6,  orifice  of  the  right 
nostril;  7,  section  of  the  inferior  maxilla;  8,  section  of  the  os  hyoides;  9,  section  of  the 
epiglottis;  10,  section  of  the  cricoid  cartilage;  11,  the  trachea,  covered  by  its  lining 
membrane;  12,  section  of  sternum;  13,  inside  of  the  upper  portion  of  the  thorax;  14, 
genio-hyoglossus  muscle;  15,  its  origin;  16,  17,  the  fan-like  expansion  of  the  fibres  of 
this  muscle;  18,  superficialis  lingua?  muscle;  19,  verticals  linguae  muscle;  20,  genio- 
hyoideus  muscle;  21,  mylo-hyoideus  muscle;  22,  anterior  belly  of  digastricus;  23,  sec- 
tion  of  platysma  myoides ;  24,  levator  menti ;  25,  orbicularis  oris ;  26,  orifice  of  Eusta- 
chian  tube;  27,  levator  palati ;  28,  internal  pterygoid;  29,  section  of  velum  pendulum 
palati,  and  azygos  uvulae  muscle;  30,  stylo- pharyngeus;  31,  constrictor  pharyngis  supe- 
rior ;  32,  constrictor  pharyngis  medius ;  33,  insertion  of  stylo-pharyngeus ;  34,  constrictor 
pharyngis  inferior;  35,  36,  37,  muscular  coat  of  oesophagus  ;  38,  thyreo-arytenoid  muscle 
and  ligaments,  and  above  is  the  ventricle  of  Galen;  39,  section  of  arytenoid  cartilage; 
40,  border  of  sterno-hyoideus.] 

1  Thus,  in  the  curious  case  formerly  referred  to  (p.  50,  note),  food  can  only  be  adminis- 
tered by  carrying  back  the  spoon  containing  it,  until  it  touches  the  fauces  and  thus  excites 
nn  act  of  deglutition.  Sensation  being  here  entirely  deficient,  there  is  nothing  to  excite  or 
to  guide  the  movements  of  the  muscles  of  the  mouth  and  tongue. 


90  OF     FOOD,    AND    THE    DIGESTIVE    PROCESS. 

apt  to  go  on  chewing  and  rechewing  what  is  already  fit  to  be  swallowed,  simply 
because  the  will  does  not  exert  itself  to  check  the  action,  and  to  carry  the  food 
backwards  within  the  reach  of  the  muscles  of  deglutition.  This  conveyance  of 
food  backwards  to  the  fauces  is  a  distinctly  voluntary  act;  and  it  is  necessary 
that  it  should  be  guided  by  the  sensation,  which  there  results  from  the  contact  it 
induces.  If  the  surface  of  the  pharynx  were  as  destitute  of  sensation  as  is  the 
lower  part  of  the  oesophagus,  we  should  not  know  when  we  had  done  what  was 
necessary  to  excite  its  muscles  to  operation. — The  muscles  concerned  in  the  Mas- 
tication .of  food  are  nearly  all  supplied  by  the  third  branch  of  the  Fifth  pair,  a 
large  proportion  of  which  is  well  known  to  have  a  motor  character.  Many  of 
these  muscles,  especially  those  of  the  cheeks,  are  also  supplied  by  the  Facial 
nerve ;  and  yet,  if  the  former  be  paralyzed,  the  latter  cannot  stimulate  them  to 
the  necessary  combined  actions.  Hence  we  see  that  the  movements  are  of  an 
associated  character,  their  due  performance  being  dependent  on  the  part  of  the 
nervous  centres,  from  which  the  motor  influence  originates.1  If  the  Fifth  pair, 
on  the  other  hand,  be  uninjured,  whilst  the  Portio  Dura  is  paralyzed,  the  move- 
ments of  Mastication  are  performed  without  difficulty;  whilst  those  connected  in 
any  way  with  the  Respiratory  function,  or  with  Expression,  are  paralyzed.  If, 
again,  the  sensory  portion  of  the  Fifth  pair  be  paralyzed,  the  act  of  Mastication 
is  very  imperfectly  performed,  even  though  the  motor  power  be  not  in  the  least 
impaired;  for  the  muscles  cannot  be  made  to  perform  the  requisite  associated 
movements  without  the  guidance  of  sensations  ;  so  that  the  morsel  lodges  between 
the  teeth  and  the  cheek,  or  beneath  the  tongue,  and  can  with  difficulty  be  kept 
in  the  appropriate  position  (Fig.  12). 

79.  When  the  reduction  of  the  food  in  the  mouth  has  been  sufficiently  accom- 
plished, it  is  carried  into  the  Pharynx,  and  is  thence  propelled  down  the  oeso- 
phagus into  the  stomach,  by  a  set  of  associated  movements,  which,  taken  together, 
constitute  the  act  of  Deglutition.  These  movements  were  first  described  in  detail 
by  Magendie;  but  his  account  requires  some  modification,  through  the  more  recent 
observations  of  Dzondi.2 — The^rsrf  stage  in  the  process  is  the  carrying-back  of 
the  food,  until  it  has  passed  the  anterior  palatine  arch ;  this,  which  is  effected  by 
the  approximation  of  the  tongue  and  the  palate,  is  a  purely  voluntary  movement. 
In  the  second  stage,  the  tongue  is  carried  still  further  backwards,  and  the  larynx 
is  drawn  forwards  under  its  root,  so  that  the  epiglottis  is  pressed  down  over  the 
rima  glottidis.  The  muscles  of  the  anterior  palatine  arch  contract  after  the  morsel 
has  passed  it,  and  assist  its  passage  backwards;  these,  with  the  tongue,  completely 
cut  off  the  communication  between  the  fauces  and  the  mouth.  At  the  same  time 
the  muscles  of  the  posterior  palatine  arch  contract  in  such  a  manner,  as  to  cause 
the  sides  of  the  arch  to  approach  each  other  like  a  pair  of  curtains,  so  that  the 
passage  from  the  fauces  into  the  posterior  nares  is  nearly  closed  by  them ;  and  to 
the  cleft  between  the  approximated  sides,  the  uvula  is  applied  like  a  valve.  A 
sort  of  inclined  plane,  directed  obliquely  downwards  and  backwards,  is  thus 
formed;  and  the  morsel  slides  along  it  into  the  pharynx,  which  is  brought-up  to 

1  Comparative  Anatomy  furnishes  the  key  to  these  phenomena,  which  seem  at  first  sight 
to  be  somewhat  strange. —  Among  Invertebrate  animals  generally,  the  Respiratory  organs 
are  completely  unconnected  with  the  mouth  ;  and  a  very  distinct  set  of  muscles  is  provided 
to  keep  them  in  action.  These  muscles  have  separate  ganglia  as  the  centres  of  their  ope- 
rations ;  and  these  ganglia  are  only  connected  indirectly  with  those  of  the  sensori-motor 
system.  The  same  is  the  case,  in  regard  to  the  introduction  of  the  food  into  the  digestive 
apparatus.  The  muscles  concerned  in  this  operation  have  their  own  centres, — the  Stomato- 
gastric  and  Pharyngeal  ganglia,  —  which  are  not  very  closely  connected,  either  with  the 
cephalic,  or  with  the  respiratory,  or  with  those  of  general  locomotion.  Now  in  the  Verte- 
brata,  the  distinct  organs  have  been  so  far  blended  together,  that  the  same  muscles  serve 
the  purposes  of  both :  but  the  different  sets  of  movements  of  these  muscles  are  excited  by 
different  nerves ;  and  the  effect  of  division  of  either  nerve,  is  to  throw  the  muscle  out  of 
connection  with  the  function  to  which  that  nerve  previously  rendered  it  subservient,  —  as 
much  as  if  the  muscle  were  separated  from  the  nervous  system  altogether. 

'  See  Prof.  Miiller's  "  Elements  of  Physiology"  (translated  by  Dr.  Baly),  p.  501. 


MOVEMENTS    OF   THE   ALIMENTARY   CANAL  —  DEGLUTITION.  91 

receive  it.  Some  of  these  acts  may  be  performed  voluntarily;  but  the  combina- 
tion of  the  whole  is  automatic.  The  third  stage  of  the  process,  the  propulsion 
of  the  food  down  the  oesophagus,  then  commences.  This  is  accomplished,  in  the 
upper  part,  by  means  of  the  constrictors  of  the  pharynx ;  and  in  the  lower,  by 
the  muscular  coat  of  the  ossophagus  itself.  When  the  morsels  are  small,  and  are 
mixed  with  much  fluid,  the  undulating  movements  from  above  downwards  suc- 
ceed each  other  very  rapidly,  as  may  be  well  observed  in  Horses  whilst  drinking; 
large  morsels,  however,  are  frequently  some  time  in  making  their  way  down. 
Each  portion  of  food  and  drink  is  included  in  the  contractile  walls,  which  are 
closely  applied  to  it  during  the  whole  of  its  transit.  The  gurgling  sound,  which 
is  observed  when  drink  is  poured  down  the  throat  of  a  person  in  articulo  mortis, 
is  due  to  the  want  of  this  contraction.  The  whole  of  the  third  stage  is  com- 
pletely involuntary. —  At  the  point  where  the  oesophagus  enters  the  stomach,  the 
'  cardiac  orifice '  of  the  latter,  there  is  a  sort  of  sphincter,  which  is  usually  closed, 
but  which  opens  when  sufficient  pressure  is  made  on  it  by  accumulated  food, 
closing  again  when  this  has  passed,  so  as  to  retain  it  in  the  stomach. 

80.  The  purely  automatic  nature  of  the  act  of  Deglutition  is  shown  by  the 
fact,  that  no  attempt  on  our  own  part  will  succeed  in  performing  it  really  volun- 
tarily.    In  order  to  excite  it,  we  must  apply  some  stimulus  to  the  fauces.     A  very 
small  particle  of  solid  matter,  or  a  little  fluid  (saliva,  for  instance),  or  the  contact 
of  the  back  of  the  tongue  itself,  will  be  sufficient;  but  without  either  of  these, 
we  cannot  swallow  at  will.     Nor  can  we  restrain  the  tendency,  when  it  is  thus 
excited  by  a  stimulus ;  every  one  knows  how  irresistible  it  is,  when  the  fauces 
are  touched  in  any  unusual  manner;  and  it  is  equally  beyond  the  direct  control 
of  the  will,  in  the  ordinary  process  of  eating, — voluntary  as  we  commonly  regard 
this.      Moreover,  this  action  is  performed,  like  that  of  respiration,  when  the 
power  of  the  will  is  suspended,  as  in  profound  sleep,  or  in  apoplexy  affecting  only 
the  brain ;  and  it  does  not  seem  to  be  at  all  affected  by  the  entire  removal  of  the 
brain,  in  an  animal  that  can  sustain  the  shock  of  the  operation ;  being  readily 
excitable,  on  stimulating  the  fauces,  so  long  as  the  nervous  structure  retains  its 
functions.     This  has  been  experimentally  proved  by  Dr.  M.  Hall ;  and  it  har- 
monizes with  the  natural  experiment  sometimes  brought  under  our  notice  in  the 
case  of  an  anencephalous  infant,  in  which  the  power  of  swallowing  seems  as 
vigorous  as  in  the  perfect  one.     But,  if  the  i  nervous  circle ;  be  destroyed,  either 
by  division  of  the  trunks,  or  by  injury  of  any  kind  to  the  portion  of  the  nervous 
centres  connected  with  them,  the  action  can  no  longer  be  performed;  and  thus 
we  see  that  when  the  effects  of  apoplexy  are  extending  themselves  from  the  brain 
to  the  spinal  cord,  whilst  the  respiration  becomes  stertorous,  the  power  of  Deglu- 
tition is  lost,  and  then  respiration  also  speedily  ceases. 

81.  Our  knowledge  of  the  nerves  specially  concerned  in  this  action  is  princi- 
pally due  to  the  very  careful  and  well-conducted  experiments- of  Dr.  J.  Reid.1 — 
The  distribntion  of  the  Glosso-pharyngeal  evidently  points  it  out  as  in  some  way 
connected  with  it;  but  this,  when  carefully  examined,  discloses  the  important  fact, 
that  the  nerve  scarcely  sends  any  of  its  branches  to  the  muscles  which  they  enter, 
these  mostly  passing  through  them,  to  be  distributed  to  the  superjacent  mucous 
surface  of  the  tongue  and  fauces.     Further,  when  the  trunk  is  separated  from 
the  nervous  centres,  irritation  produces  scarcely  any  muscular  movements.    Hence 
it  is  not  in  any  great  degree  an  'efferent'  or  motor  nerve;  and  its  distribution 
would  lead  us  to  suppose  its  chief  functions  to-  be  l  afferent ;'  namely,  the  convey- 
ance of  impressions  from  the  surface  of  the  fauces  to  the  Medulla  Oblongata. 
This  inference  is  fully  confirmed  by  the  fact  that,  so  long  as  its  trunk  is  in  con- 
nection with  the  centre,  and  the  other  parts  are  uninjured,  pinching,  or  other 
severe  irritation  of  the  Glosso-pharyngeal,  will  often  excite  distinct  acts  of  deglu- 
tition.    Such  irritation,  however,  may  excite  only  convulsive  twitches,  instead  of 

'"Edinb.   Med.   and  Surg.  JoMra."  yol.  ^Iix  :    and  "Physiological,  Anatomical,  and 
Pathological  Researches,"  CHA?.  iv. 


92  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

the  regular  movements  of  swallowing ;  and  it  is  evident  that,  here  as  elsewhere, 
the  impressions  made  upon  the  extremities  of  the  nerves  are  much  more  powerful 
excitors  of  reflex  movement,  than  are  those  made  upon  the  trunk,  though  the 
latter  are  more  productive  of  pain.  It  was  further  observed  by  Dr.  Reid,  that 
this  effect  was  produced  by  pinching  the  pharyngeal  branches  only;  no  irritation 
of  the  lingual  division  being  effectual  to  the  purpose. —  If,  then,  the  muscles  of 
deglutition  be  not  immediately  stimulated  to  contraction  by  the  glosso-pharyngeal 
nerve,  it  remains  to  be  inquired,  by  what  nerve  the  motor  influence  is  conveyed 
to  them  from  the  Medulla  Oblongata ;  and  Dr.  Reid  was  equally  successful  in 
proving,  that  this  function  is  chiefly  performed  by  the  pharyngeal  branches  of  the 
Pncumogastric.  Anatomical  examination  of  their  distribution  shows,  that  they 
lose  themselves  in  the  muscles  of  the  pharynx ;  and  whilst  no  decided  indications 
of  suffering  can  be  produced  by  irritating  them,  evident  contractions  are  occa- 
sioned, when  the  trunk,  separated  from  the  brain,  is  pinched  or  otherwise  stimu- 
lated.— It  appears,  however,  that  neither  is  the  Glosso-pharyngeal  the  sole  excitor 
nerve,  nor  are  the  pharyngeal  branches  of  the  Pueumogastric  the  sole  motor 
nerves,  concerned  in  deglutition  ;  for  after  the  former  has  been  perfectly  divided 
on  each  side,  the  usual  movements  can  still  be  excited,  though  with  less  energy ; 
and,  after  the  latter  have  been  cut,  the  animal  retains  the  means  of  forcing  small 
morsels  through  the  pharynx,  by  the  action  of  the  muscles  of  the  tongue  and 
neck.  From  a  careful  examination  of  the  actions  of  deglutition,  and  of  the  in- 
fluence of  various  nerves  upon  them,  Dr.  Reid  drew  the  following  conclusions:  — 
The  excitor  impressions  are  conveyed  to  the  Medulla  Oblongata  chiefly  through 
the  Glosso-pharyngeal,  but  also  along  the  branches  of  the  Fifth  pair  distributed 
upon  the  fauces,  and  probably  along  the  superior  laryngeal  branches  of  the  Pneu- 
mogastric  distributed  upon  the  pharynx.  The  motor  influence  passes  chiefly  along 
the  pharyngeal  branches  of  the  Pneumogastric ;  along  the  branches  of  the  Hypo- 
glossal,  distributed  to  the  museles  of  the  tongue,  and  to  the  sterno-hyoid,  sterno- 
thyroid,  and  thyro-hyoid  muscles ;  along  the  motor  filaments  of  the  Recurrent 
laryngeals;  along  some  of  the  branches  of  the  Fifth,  supplying  the  elevator 
muscles  of  the  lower  jaw;  along  the  branches  of  the  Facial,  ramifying  upon  the 
digastric  and  stylo-hyoid  muscles  and  upon  those  of  the  lower  part  of  the  face; 
and  probably  along  some  of  the  branches  of  the  Cervical  plexus,  which  unite 
themselves  to  the  descendens  noni.  It  was  further  observed  by  Dr.  Reid,  that 
the  stylo-pharyngeus  muscle  is  usually  thrown  into  contraction,  when  the  roots 
of  the  glosso-pharyngeal  nerve  are  irritated ;  and  as  this  has  been  also  noticed  by 
Mayo,  Volkmann,  and  others,  we  are  probably  to  consider  the  Glosso-pharyngeal 
as  a  motor  nerve,  in  so  far  as  that  muscle  is  concerned.1 

82.  When  the  food  has  been  propelled  downwards  by  the  Pharyngeal  muscles, 
so  far  as  their  action  extends,  its  further  progress  through  the  (Esophagus  is 
effected  by  a  kind  of  peristaltic  contraction  of  the  muscular  coat  of  the  tube 
itself.  This  movement  is  not,  however,  due  only  to  the  direct  stimulus  of  the 
muscular  fibre  by  the  pressure  of  the  food,  as  it  seems  to  be  in  the  lower  part  of 
the  alimentary  canal;  for  Dr.  J.  Reid  has  found,  by  repeated  experiment,  that 
the  continuity  of  the  03sophageal  branches  of  the  Pneumogastric  with  the  Me- 
dulla Oblongata,  is  necessary  for  the  rapid  propulsion  of  the  food;  so  that  it  can 
scarcely  be  doubted,  that  an  impression  made  upon  the  mucous  surface  of  the 
03sophagus,  conveyed  by  the  afferent  fibres  of  these  nerves  to  their  ganglionio 
centre,  and  reflected  downwards  along  the  motor  fibres,  is  the  real  cause  of  the 
muscular  contraction.  If  the  Pneumogastric  be  divided  in  the  rabbit,  on  each 
side,  above  the  cesophageal  plexus,  but  below  the  pharyngeal  branches,  and  the 
animal  be  then  fed,  it  is  found  that  the  food  is  delayed  in  the  oesophagus,  which 
becomes  greatly  distended.  Further,  if  the  lower  extremity  of  the  Pneumogas- 

1  Op.  Cit.,  pp.  258-260.  —  It  seems  not  improbable  that  the  discrepant  results  obtained 
by  different  experimenters  on  this  point,  are  partly  to  be  explained  by  differences  in  the 
distribution  of  the  nerves  in  the  several  species  of  animals  operated-on. 


MOVEMENTS    OF    THE    STOMACH.  93 

trie  be  irritated,  distinct  contractions  are  seen  in  the  O3sophageal  tube,  proceeding 
from  above  downwards,  and  extending  over  the  cardiac  extremity  of  the  stomach. 
—  We  have  here,  then,  a  distinct  case  of  reflex  action  without  sensation,  occur- 
ring as  one  of  the  regular  associated  movements  in  the  natural  condition  of  the 
animal  body }  and  it  is  very  interesting  to  find  this  following-upon  a  reflex  action 
with  sensation  (that  of  the  pharynx"),  and  preceding  a  movement  which  is  altoge- 
ther unconnected  with  the  Spinal  Cord  (that  of  the  lower  part  of  the  alimentary 
canal).  The  use  pf  sensation  in  the  former  case  has  been  already  shown  (§  78). 
The  muscular  fibres  of  the  (Esophagus  are  also  excitable,  though  usually  in  a  less 
degree,  by  direct  stimulation ;  for  it  appears  that,  in  some  animals  (the  Dog,  for 
example),  section  of  the  pneumogastric  does  not  produce  that  check  to  the  pro- 
pulsion of  the  food,  which  it  occasions  in  the  Rabbit;  and  even  in  the  Rabbit,  as 
Dr.  M.  Hall  has  remarked,1  the  simple  contractility  of  the  muscular  fibre  occa- 
sions a  distinct  peristaltic  movement  along  the  tube,  after  its  nerves  have  been 
divided ;  causing  it  to  discharge  its  contents  when  cut  across.  Such  a  movement, 
indeed,  seems  to  take  place  in  something  of  a  rhythmical  manner  (that  is,  at  short 
and  tolerably-regular  intervals,)  whilst  a  meal  is  being  swallowed ;  but  as  the  sto- 
mach becomes  full,  the  intervals  are  longer,  and  the  wave-like  contractions  less 
frequent.  —  That  the  action  of  the  Cardiac  sphincter  is  reflex,  and  is  dependent 
upon  the  l nervous  circle'  furnished  by  the  Pneumogastric  nerves  and  their  gan- 
glionic  centres,  would  appear  from  the  fact,  that  when  the  trunks  of  these  nerves 
are  divided,  the  sphincter  no  longer  contracts,  and  the  food  regurgitates  into  the 
ossophagus.  The  reopening  of  the  cardiac  orifices,  on  pressure  from  within  (which 
is  usually  resisted  by  the  sphincter,  as  in  the  acts  of  defecation,  parturition,  &c.,) 
is  one  of  the  first  of  that  series  of  reversed  actions  which  constitutes  the  act  of 
Vomiting  (§  85)  j  and  this  is  accompanied  by  a  reversed  peristaltic  action  of  the 
oesophagus.  The  independence  of  these  actions,  one  of  another,  and  their  rela- 
tion to  a  common  cause,  is  remarkably  shown  by  the  fact,  that  when  vomiting 
takes  place  as  a  consequence  of  the  injection  of  tartar-emetic  into  the  veins,  the 
reversed  peristaltic  action  of  the  oesophagus  is  performed  even  after  its  separation 
from,  the  stomach. 

[Fie  13. 


A  front  view  of  the  Stomach,  distended  by  flatus,  with  the  Peritoneal  Coat  turned  off ; 
1,  anterior  face  of  the  oesophagus ;  2,  the  cul-de-sac,  or  greater  extremity ;  3,  the  lessor 
or  pyloric  extremity;  4,  the  duodenum;  5,  5,  a  portion  of  the  peritoneal  coat  turned 
back;  6,  a  portion  of  the  longitudinal  fibres  of  the 'muscular  coat;  7,  the  circular  fibres 
of  the  muscular  coat;  8,  the  oblique  muscular  fibres,  or  muscle  of  Gavard ;  9,  a  portion  (A 
the  muscular  coat  of  the  duodenum,  where  its  peritoneal  coat  has  been  removed.] 

1  "  Third  Memoir  on  the  Nervous  System,"  \  201. 


94  OF    FOOD,     AND    THE    DIGESTIVE     PROCESS. 

83.  The  food,  which,  thus  propelled  along  the  O3sophagus,  enters  the  Stomach 
through  its  cardiac  orifice  in  successive  waves,  is  immediately  subjected  to  a 
peculiar  peristaltic  movement,  which  has  for  its  object  to  produce  the  thorough 
intermixture  of  the  gastric  fluid  with  the  alimentary  mass,  and  to  separate  the 
portion  which  has  been  sufficiently  reduced,  from  the  remainder.  The  fasciculi 
composing  the  muscular  wall  of  the  human  stomach,  are  so  disposed  as  to 
lessen  its  diameter  in  every  direction ;  and  whilst  the  cavity  is  empty,  they  are 
uniformly  contracted,  so  as  to  reduce  the  organ  to  its  smallest  dimensions.  When 
food  is  introduced,  the  contraction  of  the  parietes  as  a  whole  still  continues,  to 
such  a  degree  as  to  make  them  closely  apply  themselves  to  its  surface ;  but  the 
contraction  of  the  individual  fasciculi  alternates  with  relaxation,  in  such  a  manner 
as  to  induce  a  great  variety  of  motions  in  this  organ,  sometimes  transversely,  and 
at  other  times  longitudinally.  "  These  motions,"  remarks  Dr.  Beaumont,  who 
has  enjoyed  a  peculiar  opportunity  of  observing  them,1  "  not  only  produce  a  con- 
stant disturbance  or  churning  of  the  contents  of  the  stomach,  but  they  compel 
them  at  the  same  time,  to  revolve  about  the  interior  from  point  to  point,  and 
from  one  extremity  to  the  other."  In  addition  to  these  movements,  there  is  a 
constant  agitation  of  the  stomach,  produced  by  the  respiratory  muscles.  The 

[FIG.  14. 


A  view  of  the  interior  of  the  Stomach,  as  given  by  the  removal  of  its  anterior  parietes; 
1,  oesophagus;  2,  cardiac  orifice  of  the  stomach;  3,  its  greater  extremity,  or  cul-de-sac; 
4,  the  greater  curvature;  5,  line  of  the  attachment  of  the  omentum  majus ;  6,  the  mus- 
cular coat;  7,  the  anterior  cut  edge  of  the  mucous  coat;  8,  the  rugae  of  the  mucous  coat; 
9,  the  lesser  curvature;  10,  the  beginning  of  the  duodenum;  11,  pyloric  orifice,  or  valve; 
12,  the  first  turn  of  the  duodenum  downwards.] 

motions  of  the  stomach  itself  are  not  performed  on  any  very  exact  plan,  and  are 
much  influenced  by  the  character  of  the  ingesta,  the  state  of  the  general  system, 
and  by  other  circumstances.  The  following  is  the  ordinary  course,  however,  of 
the  revolutions  of  the  food.  "  After  passing  the  oesophageal  ring,  it  moves  from 
right  to  left,  along  the  small  arch ;  thence  through  the  large  curvature,  from  left 
to  right.  The  bolus,  as  it  enters  the  cardia,  turns  to  the  left,  passes  the  aperture, 
descends  into  the  splenic  extremity,  and  follows  the  great  curvature  towards  the 
pyloric  end.  It  then  returns,  in  the  course  of  the  smaller  curvature,  and  makes 
its  appearance  again  at  the  aperture  in  its  descent  into  the  great  curvature,  to 
perform  similar  revolutions.  These  revolutions  are  completed  in  from  one  to 
three  minutes.  They  are  probably  induced  in  a  great  measure  by  the  circular  or 
transverse  muscles  of  the  stomach.  They  are  slower  at  first,  than  after  chymifi- 
cation  has  considerably  advanced;"  at  which  time  also  there  is  an  increased  im- 

1  See  the  "  Case  of  Alexis  St.  Martin,  with  Observations  and  Experiments  by  Dr.  Beau- 
mont," republished  in  this  country  by  Dr.  Andrew  Combe.  —  This  patient  had  a  large  fistu- 
lous  orifice  in  his  stomach,  remaining  after  a  wound  which  had  laid-open  the  cavity ;  but 
his  general  health  had  been  completely  restored. 


MOVEMENTS    OF    THE     STOMACH.  95 

pulse  towards  the  pylorus.  It  is  probable  that,  from  the  very  commencement  of 
chymification,  until  the  organ  becomes  empty,  portions  of  chyme  are  continually 
passing  into  the  duodenum ;  for  the  bulk  of  the  alimentary  mass  progressively 
diminishes,  and  this  the  more  rapidly  as  the  process  is  nearer  its  completion. 
The  accelerated  expulsion  appears  to  be  effected  by  a  peculiar  action  of  the 
transverse  muscles;  and  especially  of  that  portion  of  them  which  surrounds  the 
stomach  at  about  four  inches  from  its  pyloric  extremity.  This  band  is  so  forci 

[Fio.  15. 


A  view  of  the  interior  of  the  Stomach  and  Duodenum  in  situ,  the  inferior  portion  of 
each  having  been  removed:  1,  1,  the  under  side  of  the  liver;  2,  the  gall-bladder;  3,  3, 
the  lesser  curvature  and  anterior  faces,  as  seen  from  below ;  4,  the  rugae,  about  the  car- 
diac orifice ;  5,  the  pyloric  orifice ;  6,  the  rugae,  and  thickness  of  this  orifice ;  7,  7,  the 
duodenum ;  8,  lower  end  of  the  right  kidney.] 

bly  contracted  in  the  latter  part  of  the  digestive  process,  that  it  almost  separates 
the  two  portions  of  the  stomach  into  a  sort  of  hour-glass  form ;  and  Dr.  B.  states 
that,  when  he  attempted  to  introduce  a  long  thermometer-tube  into  the  pyloric 
portion  of  the  stomach,  the  bulb  was  at  first  gently  resisted,  then  allowed  to  pass, 
and  then  grasped  by  the  muscular  parietes  beyond,  so  as  to  be  drawn-in  :  whence 
it  is  evident  that  the  contraction  has  for  its  object  to  resist  the  passage  of  solid 
bodies  into  the  pyloric  extremity  of  the  stomach,  at  this  stage  of  digestion,  whilst 
the  matter  which  has  been  reduced  to  the  fluid  form,  is  pumped-away  (as  it  were) 
by  the  action  of  that  portion  of  the  viscus.  These  peculiar  motions  continue, 
until  the  stomach  is  perfectly  empty,  and  not  a  particle  of  food  or  of  chyme 
remains ;  and  when  they  are  nearly  brought  to  a  close,  the  contraction  of  the 
pyloric  orifice  also  gives-way,  to  an  extent  sufficient  to  allow  not  only  the  undi- 
gested residue  of  the  food,  but  also  large  solid  bodies  that  may  have  been  swal- 
lowed (such  as  coins  and  the  like),  to  pass  into  the  intestinal  canal. 

84.  With  regard  to  the  degree  in  which  these  movements  of  the  Stomach, 
whose  share  in  the  Digestive  operation  is  so  important,  are  dependent  upon  the 
Spinal  cord,  and  are  consequently  of  a  'reflex'  nature,  it  is  difficult  to  speak  with 
certainty,  owing  to  the  contradictory  results  obtained  by  different  experimenters. 
These  contradictions,  however,  seem  partly  due  to  a  diversity  in  the  nature  of  the 
animals  experimented-on,  and  partly  to  a  difference  in  the  stage  of  the  digestive 
process  at  which  the  observations  were  made.  It  seems  to  be  well  established  by 
the  researches  of  Reid,  Valentin,  and  others,1  that  distinct  movements  may  be  ex- 
cited in  the  stomach  of  the  Rabbit,  if  distended  with  food,  by  irritating  the  Pneu- 
mogastric  soon  after  the  death  of  the  animal ;  these  movements  appear  to  com- 
mence from  the  cardiac  orifice,  and  then  to  spread  themselves  in  a  sort  of  peri- 

1  See  Dr.  Reid's  "  Physiological,  Anatomical  and  Pathological  Researches,"  chap.  v.  : 
Valentin  "  De  Functionibus  Nervorum  Cerebralium,"  &c.  chap.  xi. ;  also  Longet  "Anat 
et  Physiol.  du  Systeme  Nerveux,"  torn.  i.  p.  323;  and  Bischoff  in  "  Miiller's  Archiv.," 
1843. 


96  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

staltic  manner  along  the  walls  of  the  stomach :  but  no  such  movements  can  be 
excited  if  the  stomach  be  empty.  Various  experiments  upon  living  animals  have 
led  to  a  similar  conclusion,  food  taken-in  shortly  before  or  subsequently-to  its 
division,  having  been  found  to  be  only  dissolved  on  the  surface  of  the  mass,  where 
it  was  in  contact  with  the  mucous  membrane  :  but  these  experiments  have  been 
made  for  the  most  part  upon  Herbivorous  animals,  such  as  horses,  asses,  and  rab- 
bits; whose  food  is  bulky  and  difficult  of  solution,  requiring  to  be  constantly 
changed  in  its  position,  so  that  every  part  of  it  may  be  successively  brought  to 
the  exterior.  On  the  other  hand,  Dr.  Reid  found,  in  his  experiments  upon  Dogs, 
that,  after  the  first  shock  of  the  operation  had  gone-off,  solution  of  food  in  the 
stomach,  and  absorption  of  chyle,  might  take  place ;  and  hence  it  may  be  inferred, 
that  no  influence  of  this  nerve  upon  the  muscular  parietes  of  the  stomach  is  essen- 
tial to  digestion  in  that  species.  This  conclusion  harmonises  well,  therefore,  with 
the  fact  already  stated  respecting  the  absence  of  such  influence  in  the  lower  parts 
of  its  cesophagus;  and  it  may,  perhaps,  be  explained  by  the  consideration,  that 
the  natural  food  of  the  dog  is  much  less  bulky  and  more  easy  of  solution,  than 
that  of  the  animals  previously  named ;  so  that  there  is  not  so  much  need  of  that 
peculiar  movement,  which  is  in  them  so  important  an  aid  to  the  process  of  reduc- 
tion. —  There  is  yet  much  to  be  learned  on  this  subject,  however;  -especially  in 
regard  to  the  degree  in  which  the  movements  may  be  checked  or  altered,  by  im- 
pressions transmitted  through  the  nervous  system.  It  was  stated  by  Brachet,1 
that,  in  some  of  his  experiments  upon  the  Pueumogastric,  some  hours  after  sec- 
tion of  the  nerve  on  both  sides,  the  surface  only  of  the  alimentary  mass  was  found 
to  have  undergone  solution,  the  remainder  of  the  mass  remaining  in  the  condition 
in  which  it  was  at  first  ingested ;  and  if  this  statement  can  be  relied-on,  it  would 
appear  that  the  movements  of  the  stomach,  like  those  of  the  heart,  can  be  readily 
affected  by  a  strong  nervous  impression.  It  may  be  partly  in  this  manner,  there- 
fore, and  not  by  acting  upon  the  secretions  alone,  that  strong  Emotions  retard  or 
even  check  the  digestive  process,  as  they  are  well  known  to  do.  On  the  other 
hand,  the  moderate  excitement  of  pleasurable  emotions  may  be  favourable  to  the 
operation ;  not  only  by  giving  firmness  and  regularity  to  the  action  of  the  heart, 
and  thence  promoting  the  circulation  of  the  blood,  and  the  increase  of  the  gastric 
secretion  ;  but  also  in  imparting  firmness  and  regularity  to  the  muscular  contrac- 
tions of  the  stomach. 

85.  Much  discussion  has  taken  place  upon  the  question,  how  far  contraction 
of  the  parietes  of  the  Stomach  itself  actively  participates  in  the  operation  of 
Vomiting ;  and  many  experiments  have  been  made  to  determine  the  facts  of  the 
case.  Some,  like  Magendie,  have  gone  so  far  as  to  affirm  that  the  stomach  is  en- 
tirely passive ;  grounding  this  inference  upon  the  fact  experimentally  ascertained, 
that  when  the  stomach  was  removed,  and  a  bladder  was  substituted  for  it,  this 
was  emptied  of  its  contents,  by  the  compression  of  the  parietes  of  the  abdomen, 
when  tartar-emetic  was  injected  into  the  veins.  But  this  fact  by  no  means  dis- 
proves the  active  co-operation  of  the  stomach ;  and  judging  from  the  analogy  of 
the  uterus,  bladder,  and  rectum, — whose  muscular  walls  are  all  actively  concerned 
in  the  expulsion  of  their  contents,  though  that  expulsion  is  in  great  part  due  to 
the  contraction  of  the  abdominal  muscles,  —  we  should  be  led  to  concur  with  the 
common  opinion,  of  which  our  own  sensations  during  the  act  would  indicate  the  cor- 
rectness. And  this  opinion  has  been  confirmed  by  observation  of  a  case,2  in  which, 
the  abdominal  parietes  having  been  accidentally  laid-open  in  the  human  subject, 
and  the  stomach  having  wholly  protruded  itself,  it  was  seen  to  contract  itself  re 
peatedly  and  forcibly,  during  the  space  of  half  an  hour,  until  by  its  own  efforts  it 
had  expelled  all  its  contents  except  gases.  As  already  mentioned,  the  relaxation 
of  the  cardiac  sphincter  is  essential  to  the  act  of  vomiting;  and  unless  this  take 

1  "  Rech.  Exp6r.  sur  les  Fonct.  du  Syst.  Nerv.  Ganglion,"  chap.  Hi.  \  2. 
8  Lepine  in  "Bullet,  de  1'Acad.  Roy.  de  MSdecine,"  1844. 


MOVEMENTS    OF    THE    STOMACH.  97 

place,  all  the  other  movements  will  be  in  vain  :  for  its  fibres,  when  contracted, 
can  resist  the  combined  force  of  all  the  expulsor  muscles.  There  can  be  little 
doubt  that  the  violent  but  fruitless  efforts  at  vomiting  which  we  occasionally  wit- 
ness (two  or  three  such  efforts  frequently  preceding  the  effectual  one),  are  pre- 
vented from  emptying  the  stomach  by  the  obstinacy  with  which  the  cardiac 
sphincter  is  kept  closed;  just  as  the  expiratory  effort  which  assists  in  emptying 
the  stomach,  is  prevented  by  the  firmness  with  which  the  glottis  is  held  shut,  from 
expelling  the  contents  of  the  chest.  It  is  not  true,  as  was  formerly  supposed,  that 
the  diaphragm  actively  co-operates  in  the  effort  of  vomiting;  for,~~as  was  first 
pointed-out  by  Dr.  M.  Hall,1  this  effort,  like  those  of  defecation,  urination,  and 
parturition,  is  essentially  performed  by  the  muscles  of  expiration;  with  this  dif- 
ference, however,  that  the  diaphragm,  instead  of  being  passive,  is  fixed,  and  sup- 
plies a  firm  surface  against  which  the  stomach  is  pressed.  In  this,  as  in  the  other 
cases  just  referred-to,  the  expulsive  effort  is  preceded  by  a  deep  inspiration,  after 
which  the  glottis  is  spasmodically  closed  during  its  whole  continuance.  —  The 
immediate  causes  of  vomiting  may  be  reduced  to  three  different  categories. 
1st.  The  contact  of  irritating  substances  with  the  mucous  membrane  of  the 
stomach  itself;  these,  however,  cannot  act  by  direct  stimulation  upon  more  than 
its  own  muscular  coat;  and  their  operation  upon  the  associated  muscles  must  take 
place  by  reflexion,  through  the  'nervous  circle'  furnished  by  the  pneumogastrics 
and  the  motor  nerves  of  expiraiion.  2nd.  Irritations  applied  to  other  parts  of  the 
body,  likewise  operating  by  simply -re flex  transmission)  as  in  the  vomiting  which 
is  consequent  upon  the  strangulation  of  a  hernia,  or  the  passage  of  a  renal  calcu- 
lus; or  in  that  which  is  excited  by  the  injection  of  tartar-emetic  or  emetin  into 
the  circulating  current,  where  these  substances  probably  produce  their  characteris- 
tic effect  by  their  operation  on  the  nervous  centres.  3rd.  Impressions  received 
through  the  sensorial  centres,  which  may  be  either  sensational  or  emotional,  but 
which  do  not  operate  unless  they  are  felt.  In  this  mode  seems  to  be  excited  the 
vomiting  that  is  induced  by  tickling  the  fauces,  which  first  gives  rise  to  the 
sensation  of  nausea;  as  well  as  the  vomiting  consequent  upon  disgusting  sights, 
odours,  or  tastes,  and  upon  those  peculiar  internal  sensations  which  are  prelimi- 
nary to  '  sea-sickness/  The  recollection  of  these  sensations,  conjoined  with  the 
emotional  state  which  they  originally  excited,  may  itself  become  an  efficient  cause 
of  the  action,  at  least  in  individuals  of  peculiarly  irritable  stomachs,  or  of  highly 
sensitive  nervous  systems;  for  this  plays  downwards  upon  the  sensorial  centres, 
in  such  a  manner  as  to  excite  in  them  the  same  condition  as  that  which  was 
originally  produced  through  the  medium  of  the  sensory  nerve,  when  the  object 
was  actually  present.  (See  CHAP.  XL,  Sect.  3.) 

86.  The  passage  of  the  Chyme,  or  product  of  the  gastric  digestion,  through  the 
pyloric  orifice,  into  the  commencement  of  the  Intestinal  tube,  is  at  first  slow;  but 
when  the  digestive  process  is  nearly  completed,  it  is  transmitted  in  much  larger 
quantities.  The  pyloric  orifice,  like  the  cardiac,  is  furnished  with  a  sphincter 
muscle ;  but  how  far  its  contractions  are  dependent  upon  l  reflex  action/  has  not 
yet  been  ascertained.  The  ingested  matter,  which  undergoes  further  changes  of 
a  very  important  character  within  this  portion  of  the  canal,  is  gradually  propelled 
onwards  by  the  peristaltic  contractions  of  its  walls ;  and  these  are  excited  by  the 
contact,  either  of  the  products  of  digestion,  or  of  the  secretions  poured-in  by 
the  various  glands  that  discharge  their  products  into  the  intestinal  tube.2  In 
its  progress  along  the  small  intestines,  the  nutritious  portion  of  the  ingested  mat- 
ter is  gradually  taken-up  by  the  blood-vessels  and  absorbents;  and  the  residue, 
combined  with  excrenientitious  matters  separated  from  the  blood,  begins  to  assume 

1  "  Quarterly  Journal  of  Science,"  vol.  xxv.  p.  388,  et  seq. 

3  The  Bile  seems  to  have  an  important  share  in  producing  this  effect ;  since,  wheti  the 
ductus  choledochus  is  tied,  constipation  always  occurs.  The  purgative  action  of  Mercurials 
seems  to  depend  in  great  part  upon  the  increase  of  the  hepatic  and  other  secretions  which 
it  induces. 
7 


98  OF    FOOD,     AND    THE    DIGESTIVE    PROCESS 

the  faecal  character.  A  further  absorption  takes  place  during  the  passage  of  the 
faecal  matter  through  the  large  intestines ;  and  thus  by  the  time  it  reaches  the 
rectum,  it  has  acquired  a  considerable  degree  of  consistency. — The  ordinary 
Peristaltic  movements  of  the  Intestinal  canal  are  fully  accounted-for,  by  referring 
them  to  the  contractility  of  the  muscular  portion  of  its  walls,  called  into  action  by 
direct  stimulation  ;  and  that  they  are  not  in  any  degree  dependent  upon  nervous 
connection  with  the  Cerebro-spinal  centres,  is  clearly  shown  by  their  continuance 
after  the  destruction  of  these.  Some  Physiologists  suppose  that  these  movements 
are  attributable  to  l  reflex '  action,  through  a  nervous  circle  furnished  by  the  fibres 
and  ganglia  of  the  Sympathetic  system.  This  supposition,  however,  is  entirely 
unnecessary;  since  the  Hallerian  doctrine  of  the  independent  irritability  of  Mus- 
cle, the  truth  which  may  now  be  considered  as  firmly  established  (See  PRINC.  OP 
GEN.  PHYS.),  affords  an  adequate  explanation  of  them.  And  it  will  be  found,  on 
careful  examination,  to  have  no  sufficient  evidence  in  its  favour;  the  utmost  which 
experiment  can  show,  being  that  contractions  may  be  excited  through  the  medium 
of  the  Sympathetic  nerves.  But  the  experiments  of  Valentin,  who,  more  than 
any  other  Physiologist,  has  succeeded  in  obtaining  positive  results  of  this  kind, 
also  indicate  that  the  motor  influence  does  not  originate  in  the  Sympathetic  gan- 
glia, but  is  derived  from  the  Spinal  cord.1  The  following  are  his  general  results, 
so  far  as  they  apply  to  this  part  of  the  subject.  —  The  lower  part  of  the  (Esopha- 
gus in  the  neck  is  made  to  contract  peristaltically  from  above  downwards,  by  irri- 
tation of  the  roots  of  the  first  three  cervical  Spinal  nerves,  and  of  the  cervical 
portion  of  the  Sympathetic,  through  which  last  the  former  evidently  operate.  The 
thoracic  portion  of  the  oesophagus  is  made  to  contract,  by  irritation  of  the  lowest 
Sympathetic  ganglion  of  the  neck,  and  of  the  higher  thoracic  ganglia,  and  also 
of  the  roots  of  the  lower  cervical  Spinal  nerves.  Muscular  contractions  of  the 
Stomach  are  produced  in  the  rabbit,  by  irritation  of  the  roots  of  the  4th,  5th, 
6th,  and  7th  cervical  Spinal  nerves,  and  of  the  1st  thoracic,  so  that  a  distinct 
furrow  is  evident  between  the  cardiac  and  pyloric  portions  of  the  viscus ;  and  ths 
lower  the  nerve  irritated,  the  nearer  to  the  pylorus  do  the  contractions  extend. 
Irritation  of  the  first  thoracic  ganglion  of  the  Sympathetic  produces  the  same 
effect.  —  Contractions  of  the  Intestinal  tube,  varying  in  place  according  to  the 
part  of  the  Spinal  cord  experimented-on,  may  be  excited  by  irritation  of  the  roots 
of  the  dorsal,  lumbar,  and  sacral  nerves,  and  of  the  trigeminus ;  and  similar  effects 
are  produced  by  irritation  of  the  lower  part  of  the  thoracic  portion,  of  the  lumbar, 
and  of  the  sacral  portions  of  the  Sympathetic,  —  also  of  the  splanchnic,  and  of  the 
gastric  plexuses.  • 

87.  From  these  facts  it  is  evident,  that  the  movements  of  the  Intestinal  tube 
may  be  influenced  by  the  Spinal  cord ;  that  what  is  commonly  termed  the  Sym- 
pathetic nerve,  is  the  channel  of  that  influence,  by  the  fibres  which  it  derives 
from  the  Spinal  system.  But  it  by  no  means  thence  follows,  that  the  ordinary 
peristaltic  actions  of  the  muscles  in  question  are  dependent  on  a  stimulus  reflected 
through  the  spinal  cord,  rather  than  on  one  directly  applied  to  themselves.  It  is 
clear  that,  although  these  movements  are  of  the  first  importance  to  the  welfare  of 
the  system,  such  means  of  sustaining  them  are  feeble,  compared  to  those  which 
we  find  provided  for  the  maintenance  of  the  distinctly-reflex  actions  of  deglutition, 
respiration,  &c.  And  the  fact  that  they  are  capable  of  being  at  all  times  more 
easily  excited  by  stimuli  applied  to  the  muscles,  than  by  any  kind  of  irritation 
applied  to  their  nerves, —  taken  in  connection  with  the  fact  that  the  muscles  not 
only  remain  irritable,  but  will  execute  regular  peristaltic  contractions,  for  a  long 
time  after  any  such  contractions  can  be  excited  through  their  nerves, —  seems  a 
very  strong  indication  that  nervous  influence  is  not  the  ordinary  agent  in  calling 
these  movements  into  play.  On  the  other  hand,  we  do  know  that  the  peristaltic 
movements  are  affected  by  particular  states  of  mind,  or  by  conditions  of  the  bodily 

-  "De  Functionibus  Nervorum  Cerebralium  et  Nervi  Sympathici,"  book  ii.  chap.  2. 


MOVEMENTS    OF   THE   ALIMENTARY   CANAL — DEFECATION.  99 

system ;  and  the  connection  just  traced  satisfactorily  accounts  for  this,  and  is 
itself  sufficiently  explained.  —  The  Intestinal  tube,  then,  from  the  stomach  to  the 
rectum,  is  not  dependent  upon  the  Nervous  Centres  either  for  its  contractility,  or 
for  its  power  of  exercising  it,  but  is  enabled  to  propel  its  contents  by  its  own  in- 
herent powers ;  still  we  find  that  here,  as  in  other  instances,  the  nervous  centres 
exert  a  general  control  over  even  the  Organic  functions,  doubtless  for  the  purpose 
of  harmonizing  them  with  each  other,  and  with  the  conditions  of  the  organs  of 
Animal  life.  (See  CHAP,  xin  ,  Sect.  4.) 

88.  On  examining  the  outlet  by  which  the  faeces  are  voided,  we  find  that  it  is 
placed,  like  the  entrance,  under  the  guardianship  of  the  Spinal  Cord ;  subject, 
however,  to  some  control  on  the  part  of  the  Will.     In  the  lowest  animals,  the  act 
of  discharging  excrementitious  matter  is  probably  as  involuntary  as  are  the  acts 
immediately  concerned  in  the  introduction  of  nutriment;  and  it  is  performed  as 
often  as  there  is  anything  to  be  got  rid  of.     In  the  higher  classes,  however,  such 
discharges  are  much  less  frequent;  and  reservoirs  are  provided,  in  which  the 
excrementitious  matter  may  accumulate  in  the  intervals.     The  associated  move- 
ments required  to  empty  these,  are  completely  involuntary  in  their  character ; 
and  are  excited  by  the  quantity,  or  stimulating  quality,  of  the  contents  of  the 
reservoir.     But,  had  volition  no  control  over  them,  great  inconvenience  would 
ensue ;  hence  sensation  is  excited  by  the  same   stimulus  which  produces  the 
movements,  in  order  that,  by  arousing  the  will,  the  otherwise  involuntary  motions 
may  be  restrained  and  directed. — There  can  be  little  doubt,  from  the  experiments 
of  Dr.  M.  Hall,  as  well  as  from  other  considerations,  that  the  associated  movements 
by  which  the  contents  of  the  rectum  and  bladder  are  discharged,  correspond  much 
with  those  of  Respiration;  being  in  their  own  nature  excito-motor,  but  being 
capable  of  a  certain  degree  of  voluntary  restraint  and  assistance.  The  act  of  Defe- 
cation (as  of  Urination)  chiefly  depends  upon  the  combined  contraction  of  the 
abdominal  muscles,  similar  to  that  which  is  concerned  in  the  expiratory  move- 
ment; but,  the  glottis  being  closed  so  as  to  prevent  the  upward  motion  of  the 
diaphragm,  their  force  acts  only  on  the  contents  of  the  abdominal  cavity;  and  so 
long  as  the  sphincter  of  the  cardia  remains  closed,  it  must  press  downwards  upon 
the  walls  of  the  rectum  and  bladder, —  the  contents  of  the  one  or  the  other  of 
these  cavities,  or  of  both,  being  expelled,  according  to  the  condition  of  their  re- 
spective sphincters.     These  actions  are  doubtless  assisted  by  the  contraction  of 
the  walls  of  the  rectum  and  bladder  themselves;  for  we  sometimes  find  their 
agency  sufficient  to  expel  the  contents  of  the  cavities,  when  there  is  a  total 
paralysis  of  the  ordinary  expulsors,  provided  that  the  sphincters  be  at  the  same 
time  sufficiently  relaxed.     This  is  more  especially  the  case,  when  their  power  is 
augmented  by  increased  nutrition.     For  example,  in  many  cases  of  disease  or 
injury  of  the  Spinal  Cord,  the  bladder  ceases  to  expel  its  contents,  through  the 
interruption  of  the  circle  of  reflex  action ;  but  after  a  time,  the  necessity  for 
drawing-off  the  urine  by  the  catheter  is  found  to  exist  no  longer,  the  fluid  being 
constantly  expelled  as  soon  as  it  has  accumulated  in  small  quantities,      [n  such 
cases,  the  mucous  coat  is  found  after  death  to  be  thickened  and  inflamed ;  and 
the  muscular  coat  to  be  greatly  increased  in  strength,  and  contracted  upon  itself. 
It  would  seem,  then,  that  the  abnormal  irritability  of  the  mucous  membrane,  and 
the  increased  nutrition  of  the  muscular  substance  which  appears  consequent  upon 
it,  enable  the  latter  to  expel  the  urine  without  the  assistance  of  the  ordinary 
expulsors. 

89.  On  the  other  hand,  the  sphincters  which  antagonize  the  expellent  action, 
are  usually  maintained  in  a  state  of  moderate  contraction,  so  as  to  afford  a  con- 
stant check  to  the  egress  of  the  contents  of  the  cavities;  and  this  condition  has 
been  fully  proved  by  Dr.  M.  Hall,  to  result  from  their  connection  with  the  Spinal 
Cord,  ceasing  completely  when  this  is  interrupted.     But  the  sphincters  are  cer- 
tainly in  part  controlled  by  the  Will,  and  are  made  to  act  in  obedience  to  the 
warning  given  by  sensation ;  and  this  voluntary  power  is  frequently  destroyed  by 


100      OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 

injuries  of  the  Brain,  whilst  the  Spinal  Cord  remains  able  to  perform  all  its  own 
functions,  so  that  discharge  of  the  urine  and  faeces  occurs.  —  In  their  state  of 
moderate  excitement,  the  expulsors  and  the  sphincters  may  be  regarded  as 
balancing  one  another,  so  far  as  their  reflex  action  is  concerned ;  the  latter  having 
rather  the  predominance,  so  as  to  restrain  the  operation  of  the  former.  But, 
when  the  quantity  or  quality  of  the  contents  of  the  cavity  gives  an  excessive 
stimulus  to  the  former,  their  action  predominates,  unless  the  Will  be  put  in  force 
to  strengthen  the  resistance  of  the  sphincter;  this  we  are  frequently  experiencing, 
sometimes  to  our  great  discomfort.  On  the  other  hand,  if  the  stimulus  be  defi- 
cient, the  will  must  aid  the  expulsors,  in  order  to  overcome  that  resistance  which 
is  due  to  the  reflex  contraction  of  the  sphincters ;  of  this  also  we  may  convince 
ourselves,  when  a  sense  of  propriety,  or  a  prospective  regard  to  convenience, 
occasions  us  to  evacuate  the  contents  of  the  rectum  or  bladder  without  a  natural 
call  to  do  so. 

4.    Of  the  Changes  which  the  Food  undergoes,  during  its  passage  along  the 

Alimentary  Canal. 

90.  The  object  of  the  Digestive  process,  as  already  pointed-out,  is  to  reduce 
the  Alimentary  matters  to  a  condition  in  which  they 
FlG-  16>  can  be  introduced  by  Absorption  into  the  Circulating 

system.  This  reduction  is  partly  eifected,  as  we  have 
seen,  by  Mechanical  means;  but  it  is  chiefly  due  to  the 
Chemical  agencies  which  are  brought  to  bear  upon  the 
ingested  substances,  during  their  transit  through  the 
mouth,  the  stomach,  and  the  upper  portion  of  the  in- 
testinal tube.  The  first  of  these  is  exerted  by  the  Sali- 
vary fluid,  which  is  incorporated  with  the  food  in  the 
act  of  mastication,  and  of  which  a  large  quantity  de- 
scends with  it  to  the  stomach.  For  the  secretion  of 
this  fluid,  it  will  be  remembered  that  three  pairs  of 
glands  of  considerable  size  are  provided ;  namely,  the 
parotid,  the  snblingual,  and  the  submaxillary.  But  in 
Lobule  of  Parotid  Gland  of  addition  to  t}  a  important  part  of  the  fluid  is 

a  new-born    infant,   injected   f        •  i      i    i         i  e>  n-      i          i       i      i     t       i    • 

with  mercury.    Magnified  50  Crushed  by  the  numerous  folhcular  glands  lodged  in 

diameters.  an(*  beneath  the  buccal  mucous  membrane.      Ihe  feali- 

vary  glands  are  constructed  upon  that  follicular  type,  of 

which  a  characteristic  example  is  presented  in  the  glands  of  Brunner  (Fig.  25)  ; 
their  ultimate  follicles  (Fig.  16)  are  very  minute  (their  average  diameter  being 
about  l-1200th  part  of  an  inch),  and  are  closely  surrounded  by  a  plexus  of  capil- 
lary blood-vessels  (Fig.  17).  Their  development 
commences  from  a  simple  canal,  sending  off  bud- 
like  processes,  which  opens  from  the  mouth,  and 
lies  amidst  a  cellular  blastema;  and  as  their  evo- 
lution advances,  the  large  parent-cells  of  this 
blastema  form  communications  with  the  gland- 
canal,  which  is  at  the  same  time  extending  its 
ramifications,  and  remain  as  the  terminal  follicles 
of  these. 

91.  The  inquiry  into  the  chemical  constitution 
Capillary  Network  around  the  folli-    and  properties  of  the  Saliva  had  for  the    most 
cles  of  the  Parotid  Gland,  part  been   limited,   until   recently,   to   the   fluid 

obtained   from   the   mouth,  rather  than   to   that 

secreted  by  the  glands;  but  late  researches  have  shown,  that  the  characters  of 
the  fluids  poured-forth  respectively  from  the  three  principal  glands  are  by  no 
means  identical ;  and  that  the  buecal  mucus  has  a  very  important  share  in  the 


PROPERTIES  OF  THE   SALIVARY  SECRETION. 


101 


operations  of  that  mixed  product,  which  constitutes  the  ordinary  Saliva.  The 
specific  gravity  of  this  fluid  is  usually  (according  to  Lehinann)  from  1004  to 
1006;  but  he  states  that  it  may  rise  to  1008  or  1009,  or  may  sink  to  1002,  with- 
out any  indication  of  coexisting  disease  :  according  to  Jacubowitsch,  however,  its 
average  specific  gravity  is  no  higher  than -1002 -6.  When  examined  microscopi- 
cally, the  Saliva  is  found  to  contain  a  small  number  of  minute  corpuscles  derived 
from  the  Salivary  glands,  and  large  epithelial  scales  thrown-off  by  the  buccal  mu- 
cous membrane.  Its  reaction  is  always  alkaline  in  health ;  but  the  degree  of 
alkalinity  varies,  being  greatest  during  and  after  meals,  and  least  after  prolonged 
fasting,  when  the  fluid  is  almost  neutral.  —  The  following  are  two  of  the  most 
recent  analyses  of  this  fluid  that  have  been  made;  the  one  by  the  most  eminent 
chemist  Frerichs,1  whose  contributions  to  the  Physiology  of  Digestion,  are  among 
the  most  valuable  of  the  results  which  have  been  furnished  by  recent  inquiries 
in  this  direction ;  and  the  other  by  Jacubowitsch,2  under  the  direction  of  MM. 
Bidder  and  Schmidt. 


Dr.  Frerichs. 

Water 994-10 

Solid  Matters 5-90 


Ptyalin,  with  a  little  alcohol-extract 

Mucus  and  epithelium 

Fatty  matter 

Sulphocyanide  of  potassium 

Alkaline  and  \    f    Chlorides    j 

Earthy       f  \  Phosphates  L 

Oxide  of  Iron ) 


1-41 

2-13 
•07 
•10 

2-19 


100-00 


Jacubowitsch. 

Water 995-16 

Solid  Matters 4-84 


Soluble  Organic  matter  (Ptyalin)... 
Epithelium 

Sulphocyanide  of  potassium 

Fixed  Salts  —  Phosphates  of  soda, 

lime  and  magnesia 
"  Chlorides  of  Sodium 

and  Potassium..., 


1-34 

1-62 

•06 

•98 
•84 


100-00 


The  density  of  the  Saliva,  as  indicated  both  by  its  specific  gravity,  and  by  the 
per-centage  of  solid  matter  which  it  contains,  is  by  no  means  constant,  either  in 
different  individuals,  or  in  the  same  individual  at  different  times.  The  variations 
appear  partly  referable  to  the  amount  of  solids  and  liquids  ingested,  and  to  the 
amount  of  the  secretion  previously  poured-ont ;  but  they  may  be  partly  attributed 
to  a  difference  in  the  proportions  of  the  fluids  poured  into  the  mouth  by  the 
several  glands  which  secrete  them.  —  The  substance  to  which  the  designation  of 
Ptyalin  is  given,  is  that  on  whose  presence  the  peculiar  properties  of  the  Saliva 
appear  to  depend;  and  it  seems,  as  regards  its  chemical  nature,  to  be  an  albumi- 
nous compound,  in  such  a  state  of  change,  however,  that  it  acts  the  part  of  a  {  fer- 
ment.'3-— The  presence  of  Sulphocyanogen  is  interesting,  not  only  because  saliva 
is  the  only  animal  product  in  which  it  is  known  to  occur,  but  because  the  uni- 
formity with  which  it  makes  its  appearance  when  searched-for,  would  seem  to 
indicate  that  it  performs  some  peculiar  part  in  the  operations  to  which  the  sali- 
vary fluid  is  subservient.  Moreover,  in  a  medico-legal  point  of  view,  the  existence 

1  See  "Canstatt's  Jahresbericht,"  1850,  p.  136;  and  "Wagner's  Handworterbuch,"  band 
iii.,  Art.  '  Verdauung.' 

a  Inaugural  Dissertation,  "  De  Saliva,"  Dorpati,  1848;  see  also  Bidder  and  Schmidt, 
"  Die  Verdauungssaefte  und  der  Stoffwechsel,"  1852. 

3  The  following,  according  to  Prof.  Lehmann  ("  Physiological  Chemistry,"  Cavendish  So- 
ciety's Ed.,  vol.  ii.  p.  15),  are  the  distinctive  chemical  characters  of  Ptyalin.  —  Being  held 
in  solution  by  an  alkali,  the  addition  of  a  little  acetic  acid  throws  down  a  flocculent  precipi- 
tate, which  readily  dissolves  in  an  excess  of  the  acid.  When  boiled  with  hydrochlorate  of 
ammonia  or  snlphate  of  magnesia,  the  alkaline  solution  of  ptyalin  becomes  very  turbid ;  it 
is  precipitated  by  tannic  acid,  bichloride  of  mercury,  and  basic  acetate  of  lead ;  but  not  by 
alum,  sulphate  of  copper,  &c.  The  acetic  acid  solution  is  strongly  precipitated  on  the  addi- 
tion of  ferrocyanide  of  potassium;  and  when  boiled  with  nitric  acid,  it  yields  a  yellow  solu- 
tion. By  these  reactions  it  is  shown  that  ptyalin  closely  resembles  both  albumen  and  casein, 
without  being  identical  with  either  of  them.  [The  converting  power  of  ptyalin  is  so  great 
that,  according  to  Mialhe  (Mem.  sur  la  digestion  et  assimilation  des  matie'res  amyloides, 
1840),  one  part  of  the  pure  ferment  will  convert  2000  parts  of  starch  into  sugar. — ED.] 


102  OP    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

of  a  sulphocyanide  in  the  saliva  has  a  special  importance  \  since,  if  in  a  state  of 
sufficient  concentration,  it  causes  the  saliva  to  exhibit  the  same  blood-red  colour, 
when  treated  with  a  per-salt  of  iron,  as  that  which  is  produced  by  meconic  acid. 
(The  difference  between  the  two,  however,  is  easily  made  apparent,  by  adding  a 
solution  of  perchloride  of  mercury  •  for  this  causes  the  colour  produced  by  the 
sulphocyanide  to  disappear,  whilst  it  has  no  action  on  that  which  is  due  to  the 
presence  of  meconic  acid.)  —  The  Salts  of  the  Saliva,  with  the  exception  of  the 
foregoing,  seem  to  correspond  closely  with  those  of  the  blood ;  and  its  alkaline 
reaction  appears  due,  not  to  the  presence  of  a  free  alkali,  but  to  that  of  the  basic 
phosphate  of  soda.  The  'tartar'  which  collects  on  the  teeth,  consists  principally 
of  the  earthy  phosphates,  which  are  held-together  by  about  20  per  cent  of  animal 
matter;  and  the  same  may  be  said  of  the  salivary  concretions  which  occasionally 
obstruct  the  ducts. 

92.  From  the  experiments  of  MM.  Magendie1  and  Cl.  Bernard,2  Bidder  and 
Schmidt  (Op.  cit.),  and  others,  however,  on  the  secretions  of  the  respective  glands, 
as  obtained  directly  from  themselves  by  tubes  passed  into  their  ducts,  it  appears 
that  their  composition  and  physical  characters  are  by  no  means  identical.  For 
the  fluid  of  the  parotid  and  sublingual  glands  is  clear,  and  as  limpid  and  thin  as 
water,  and  contains  but  a  small  proportion  of  solid  matters  (not  more  than  047 
per  cent  in  the  dog,  and  0*76  per.  cent  in  the  horse,  according  to  Lehmann  and 
Jacubowitsch) ;  whilst  the  fluid  of  the  submaxillary  is  thick  and  viscid,  resem- 
bling in  colour  and  consistence  ordinary  simple  syrup,  and  containing  a  far  larger 
amount  of  solid  matters,  in  which  the  organic  components,  however,  bear  a  smaller 
proportion  to  the  salts,  than  they  do  in  the  fluid  of  the  other  two  glands.  Now 
it  has  been  observed  by  Bernard,  that  the  flow  of  saliva  which  takes  place  during 
mastication  proceeds  almost  entirely  from  the  parotid  and  sublingual  glands ; 
whilst,  during  the  act  of  deglutition,  when  the  tongue  carries  the  bolus  back  into 
the  pharynx,  the  secretion  of  the  submaxillary  is  the  greatest.  Hence  it  seems 
reasonable  to  conclude,  that  the  purpose  of  these  secretions  is  not  identical ;  that 
of  the  parotid  and  sublingual  being  to  saturate  the  food,  when  mixed-up  with  it 
in  the  act  of  mastication ;  whilst  that  of  the  submaxillary  seems  rather  destined 
to  facilitate  deglutition.3  The  fluids  which  are  secreted  by  the  three  principal 
glands,  moreover,  appear  (from  the  experiments  to  be  presently  cited)  to  have 
very  different  degrees  of  efficacy,  in  producing  that  chemical  change  in  the  food 
which  it  is  the  peculiar  attribute  of  this  secretion  to  exert  (§  93).  —  Of  the  quan- 
tity of  Saliva  which  is  secreted  daily,  it  is  impossible  to  form  an  exact  estimate, 
since  it  varies  greatly  with  the  character  of  the  food  ingested,  and  the  frequency 
with  which  that  food  is  taken  j  the  secreting  process  being,  indeed,  almost  sus- 
pended when  the  masticator  muscles  and  tongue  are  completely  at  rest,  unless 
excited  by  a  nervous  stimulus.4  The  taste,  the  sight,  or  even  the  idea,  of  savoury 
food,  is  sufficient  to  cause  a  flow  of  saliva,  especially  after  a  long  fast :  but  it  is  by 
the  masticatory  movements  that  this  flow  is  chiefly  promoted,  so  that  the  amount 

1  "  Eapport  lu  dans  la  Seance  de  1'Institut,"  Oct.  25,  1845. 
a  "Archives  Generates  de  Me"decine,"  4ieme  serie,  torn.  xiii. 

3  This  idea  of  M.  Bernard's  was  confirmed  by  the  following  experiments.     He  made  an 
opening  into  the  O3sophagus  of  a  Horse,  from  which  he  drew  the  alimentary  bolus  as  it 
descended;  and  on  weighing  it,  he  found  that  by  the  imbibition  of  saliva  it  had  increased 
eleven  fold.     He  next  tied  Wharton's  duct,  and  found  that  the  animal  required  41  minutes 
to  masticate  what  had  previously  required  only  9  minutes ;  and  the  mass,  when  withdrawn 
from  the  ossophagus,  was  covered  with  mucus  and  a  glutinous  fluid,  the  interior  being  dry 
and  friable,  and  the  whole  increased  in  weight  only  three  and  a  half  times. — An  interesting 
fact  in  Comparative  Anatomy,  which  fully  confirms  the  results  of  the  above  observations, 
has  recently  been  brought  to  light  by  Prof.  Owen  ;  for  he  has  ascertained  that  in  the  Great 
Ant-eater  (Myrmecophaga  jubata],  whose  enormously  elongated  tongue  is  kept  moist  by  a 
large  quantity  of  a  peculiarly  viscid  saliva,  for  the  purpose  of  entrapping  its  prey,  the  Pa- 
rotid gland  is  of  no  unusual  size,  whilst  the  Submaxillary  gland  extends  not  only  along  a 
great  part  of  the  elongated  jaws,  but  backwards  into  the  neck. 

4  Of  the  recent  researches  by  Ludwig,  on  the  influence  of  the  Nervous  system  on  the 
Becretion  of  saliva,  an  account  will  be  given  iu  CHAP.  xv. 


TRANSFORMING    ACTION    OF    SALIVA    UPON    FOOD.        103 

poured-forth  will  in  a  great  degree  depend  upon  the  duration  of  these  move- 
ments, —  this,  again,  being  governed  by  the  degree  in  which  the  food  requires 
mechanical  reduction.  It  is  calculated  by  MM.  Bidder  and  Schmidt,  that  the 
average  in  Man  is  at  about  3|  pounds  daily;  and  high  as  this  estimate  seems, 
yet  it  is  based  on  data  apparently  satisfactory. 

98.  There  can  be  no  doubt  that  one  most  important  action  of  the  Saliva  upon 
the  food,  consists  in  preparing  it  for  the  chemical  operations  to  which  it  is  to  be 
afterwards  subjected;  by  promoting  its  mechanical  reduction  in  the  act  of  masti- 
cation, and  by  facilitating  the  subsequent  admixture  of  other  watery  fluids, 
through  the  intimacy  with  which  it  is  incorporated  with  the  alimentary  matter. 
But  there  can  be  no  doubt  that  the  peculiar  ferment  of  the  saliva  has  itself  a 
chemical  action  upon  the  farinaceous  elements  of  food;  for  it  has  been  experimen- 
tally proved  to  have  the  power  of  converting  starch  or  dextrin  into  grape-sugar. 
This  power  is  not  peculiar,  however,  to  the  Saliva;  for  M.  Bernard  has  shown 
that  many  azotized  substances,  in  a  state  of  incipient  decomposition,  exert  a  simi- 
lar agency :  still  it  appears  to  be  possessed  by  ptyalin  in  a  much  greater  degree 
than  by  any  of  these  (save  the  pancreatic  fluid,  which  resembles  saliva  in  this 
property),  the  transformation  of  starch  under  its  influence  commencing  imme- 
diately, and  continuing  energetically  until  it  is  entirely  effected  ;  whilst  in  other 
cases,  it  is  a  work  of  much  longer  time,  as  the  comparative  experiments  of  MM. 
Bidder  and  Schmidt  (Op.  cit.)  have  fully  demonstrated.  It  further  appears  from 
the  very  ingenious  researches  of  these  enquirers,  taken  in  connection  with  the 
previous  results  obtained  by  M.  Cl.  Bernard,  that  the  secretion  of  neither  pair  of 
salivary  glands  is  by  itself  effectual  in  producing  this  change,  but  that  an  ad  mix- 
ture of  the  buccal  mucus  is  requisite  for  the  generation  of  the  peculiar  'ferment/1 
This  transforming  process  is  not  checked  (as  is  usually  supposed)  on  the  passage 
of  the  food  into  the  stomach ;  for  although  it  has  been  usually  stated  that  an 
alkaline  condition  of  the  fluid  is  necessary  for  the  operation  of  the  t  ferment,'  yet 
it  has  been  shown  by  Frerichs,  Jacubowitsch,  Lehmann,  Bence  Jones,  and 
Schroeder,  that  this  action  continues  in  the  stomach,  notwithstanding  the  acid 
condition  which  the  Salivary  fluid  then  acquires  from  admixture  with  the  gastric 
fluid.2  —  No  satisfactory  evidence  has  yet  been  obtained,  that  the  Saliva  has  any 

1  While  it  is  certain,  however,  that  an  admixture  of  the  secretion  of  the  submaxillary 
glands  with  the  buccal  mucus,  forms  an  effective  saliva,  it  is  doubtful  whether  the  secre- 
tion of  the  parotid  gland,  even  when  mingled  with  buccal  mucus,  can  exert  any  special 
action  upon  starch ;  the  results  of  the  experiments  of  MM.  Bidder  and  Schmidt  having  led 
them  to  believe  that  it  cannot,  whilst  those  of  Jacubowitsch  conducted  him  to  an  affirma- 
tive conclusion,  and  those  of  M.  Cl.  Bernard  led  him  to  regard  the  buccal  mucus  as  by 
itself  the  essential  agent  in  the  transformation.  This  point,  therefore,  remains  to  be  set- 
tled by  further  investigation. 

3  The  positive  evidence  of  these  experiments  must  be  admitted  as  more  than  counter  - 
balancing  the  negative  results  of  MM.  Bidder  and  Schmidt.  Those  of  Schroeder,  in  par- 
ticular, contained  in  his  Inaugural  Dissertation  "  Succi  Gastrici  Humani  Vis  Digestiva," 
(Dorpati  Livonorum,  1853),  are  peculiarly  valuable  as  having  been  made  on  the  Human 
subject  (in  a  case  of  gastric  fistula) ;  while,  as  those  of  Bidder  and  Schmidt  were  mad& 
upon  Dogs,  the  negative  result  which  they  obtained  may  be  fairly  attributed  to  the  inferior 
transforming  power  of  their  salivary  ferment,  and  the  stronger  acidity  of  their  gastric  fluid. 

[Experiments  made  upon  Starch  out  of  the  body  go  to  show  the  necessity  for  an  alkaline 
condition  of  the  Saliva ;  for  if  this  secretion  be  mixed  with  boiled  Starch,  the  Tincture  of 
Iodine  will  at  first  reveal  the  presence  of  that  substance ;  shortly  after  the  same  test  shows 
the  presence  of  Dextrine  by  producing  a  red  precipitate ;  and  subsequently  the  application 
of  Trommer's  test  declares  the  presence  of  glucose.  But  if  the  saliva  be  previously  ren- 
dered slightly  acid  by  the  addition  of  a  small  quantity  of-  Chlorohydric  acid,  none  of  the 
above  changes  take  place,  and  Trommer's  test  shows  only  the  presence  of  the  black  Oxide 
of  Copper. 

Some  experiments  recently  performed  by  Prof.  J.  C.  Dalton,  of  New  York  (Amer.  Jour, 
of  Med.  Sciences,  Oct.,  1854),  confirm  Bernard's  observations  in  relation  to  the  non-con- 
version of  starch  in  the  stomach.  Either  cooked  or  raw  starch  introduced  Into  the  stomach 
of  a  dog,  is  easily  recognizable  by  its  reaction  with  Iodine,  ten,  fifteen,  and  twenty  minutes 
afterwards.  In  forty-five  minutes  it  is  diminished  in  quantity,  and  in  one  hour  has  almost, 


104 


OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 


chemical  action  upon  azotized  substances;  and,  consequently,  as  regards  these 
constituents  of  the  food,  its  operation  must  be  considered  as  purely  physical.  We 
shall  find  that  a  different  secretion  is  provided  for  their  transformation,  which  has 
no  action  upon  farinaceous  matter.1 

94.  On  its  entrance  into  the  Stomach,  the  food  is  subjected  to  the  operation 
of  the  Gastric  Juicej  which  is  secreted  by  the  follicles  in  its  walls,  or  by  a  certain 


FIG.  18. 


FIG.  19. 


Vertical  section  of  the  Mucous 
Membrane  of  the  Stomach)  near 
the  pylorus; — A,  magnified  3 
times ;  B,  magnified  20  times. 


Capillary  network  of  the  lining  membrane 
of  the  Stomach,  with  the  orifices  of  the  gastric 
follicles. 


part  of  them.  This  follicular  apparatus  is  extremely  extensive,  and  makes-up 
the  chief  part  of  the  thickness  of  the  gastric  mucous  membrane.  If  this  be  divided 
by  a  section  perpendicular  to  the  surface  (Fig.  18),  it  is  seen  to  be  almost  entirely 
composed  of  a  multitude  of  parallel  tubuli  closely  applied  to  each  other,  their 
csecal  extremities  abntting  against  their  submucous  tissue,  and  their  open  ends 

invariably  disappeared  ;  but  no  sugar  is  to  be  detected  at  any  time.  Gastric  juice  outside 
the  body,  produces  the  same  effect  as  the  artificially  acidulated  saliva,  as  is  also  proved  by 
the  action  of  Tincture  of  Iodine.  — ED.] 

1  An  excellent  summary  of  the  state  of  our  knowledge  (up  to  that  date)  of  the  charac- 
ters and  offices  of  the  Saliva,  was  given  by  Dr.  Bence  Jones  in  the  "  Medical  Times"  for 
May  31,  1851.  An  account  of  M.  Bernard's  researches  will  be  found  in  the  "Amer. 
Journ.  of  Med.  Sci.,"  Oct.  1851,  and  also  in  the  "Brit,  and  For.  Med.-Chir.  Rev.,"  vol.' 
xiii.  p.  54.  The  Second  Volume  of  Prof.  Lehmann's  Physiological  Chemistry  also  contains 
a  large  amount  of  information  on  this  subject.  But  the  most  recent  general  summary,1 
containing  an  analysis  of  MM.  Bidder  and  Schmidt's  results,  and  a  comparison  of  them 
with  those  of  other  experimenters,  is  that  given  by  Prof.  Day  in  the  "  Brit,  and  For.  Med.- 
Chir.  Rev.,"  vol.  xii.  pp.  167  et  seq.  —  Among  the  most  important  special  contributions  to 
the  chemical  and  physiological  history  of  the  Saliva,  not  previously  referred-to,  are  those 
of  Leuchs,  by  whom  the  discovery  of  its  power  of  transforming  starch  into  sugar  was  first 
made  ("Kastner's  Archiv.,"  1831,  quoted  in  Miiller's  "Elements  of  Physiology,"  p.  577), 
Mialhe  ("  Memoire  sur  la  digestion  et  Passimilation  des  maticres  amyloides  et 
J846"),  and  Tilanus  ("De  Saliva  et  Muco,"  diss.  inaug.,  'Amstelod,'  1849). 


CHANGES    OF    FOOD    IN   THE    ALIMENTARY    CANAL. 


105 


being  directed  towards  the  cavity  of  the  stomach.  Between  the  tubuli,  blood 
vessels  pass-up  from  the  submucous  tissue,  and  form  a  vascular  net-work  on  its 
surface,  in  the  interspaces  of  which  the  orifices  of  the  tubes  are  seen  (Fig.  19). 
These  tubular  glands,  however,  have  not  everywhere  the  same  structure.  In 
that  which  may  be  considered  as  their  most  characteristic  form,  and  which  pre- 
sents itself  over  the  greater  part  of  the  area  of  the  membrane,  the  wide  open 
orifice  leads  to  a  pit  of  no  great  depth  (Fig.  20,  o),  lined  by  cylinder-epithelium 
resembling  that  of  the  surface  with  which  it  is  continuous;  and  from  the  bottom 
of  this  pit,  two  or  more  passages  (b,  b~)  branch-off,  still  lined  by  cylinder-epithe- 
lium, which  speedily  subdivide  into  the  proper  glandular  caeca  (c,  c).  Each  of 
these  caeca,  when  sufficiently  magnified  (Fig.  21),  is  found  to  be  composed  of  a 


FIG.  20. 


FIG.  21. 


FiG.  20.  Peptic  gastric  gland  ;  —  a,  common  trunk  ; 
b,  b,  its  chief  branches;  c,  c,  terminal  caeca  with  sphe- 
roidal gland-cells. 

FIG.  21.  Portions  of  one  of  the  caeca  more  highly 
magnified,  as  seen  longitudinally  (A),  and  in  transverse 
section  (B)  ;  —  a,  basement  membrane ;  b,  large  glandu- 
lar cells;  c,  small  epithelium-cells  surrounding  the 
cavity. 

delicate  basement-membrane  (a),  inflected  over  a  series  of  nearly  globular  cells 
(&),  which  occupy  almost  the  whole  cavity  of  the  tube,  and  which  contain  a  finely- 
granular  matter;  the  narrow  passage  left  vacant  in  the  centre,  however,  is  still 
surrounded  by  a  layer  of  epithelial  cells  (c),  whose  small  size  is  in  -striking  con- 
trast to  the  large  dimensions  of  the  gland-cells.  When  a  transverse  section  is 
made  through  a  cluster  of  caeca  connected  with  a  single  external  orifice,  they  are 
found  to  be  held-together  in  a  bundle  (Fig.  22)  by  the  interposition  of  areolar 
tissue,  a  thicker  layer  of  which  surrounds  the  whole  fasciculus,  and  isolates  it 
from  others ;  whilst  between  the  caeca  are  observed  'the  orifices  (a,  a)  of  the 
divided  capillary  vessels  which  pass-up  amongst  them.  —  A  different  type  of  glan- 
dular structure  frequently  presents  itself,  however,  especially  near  the  pylorus ; 
for  the  superficial  orifice  leads  into  a  long  and  wide  follicle  (Fig.  23,  a),  lined 
with  cylinder-epithelium,  and  branching-out,  as  it  approaches  the  submucous  tis- 
sue, into  a  small  number  of  short  follicles  (b,  b),  still  lined  by  an  epithelium  of 


106 


OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 


the  same  kind.  The  difference  between  these  two  forms  has  been  distinctly 
made-out  in  the  Dog,  Pig,  and  other  Mammalia;  it  has  not  yet  been  recognized, 
however,  in  Man,  although  its  existence  is  probable.  —  No  positive  statement  can 
be  made  with  regard  to  the  relative  functions  of  these  two  orders  of  glandulse ; 
but  there  appears  strong  reason  to  regard  the  first  of  them  as  the  instrument  of 
the  secretion  of  gastric  fluid,  while  the  office  of  the  second  is  simply  to  furnish 


FIG.  22. 


FIG.  23. 


[FiG.  24. 


FIG.  22.  Transverse 
section  passing  though  a 
cluster  of  gastric  caeca, 
separated  and  surrounded 
by  fibrous  tissue ;  a,  a, 
orifices  of  divided  capil- 
laries. 

FIG.  23.  Mucous  gas- 
tric gland,  with  cylinder- 
epithelium  ;  ct,wide  trunk ; 
b,  b,  its  csecal  appendages. 


Horizontal  section  of  a  stomach- 
cell,  a  little  way  within  its  orifice. 
a.  Basement  membrane,  b.  Co- 
lumnar epithelium.  All  but  the 
centre  of  the  cavity  of  the  cell  is 
occupied  by  transparent  mucus, 
which  seems  to  have  oozed  from 
the  open  extremities  of  the  epi- 
thelial particles,  c.  Fibrous  ma- 
trix surrounding  and  supporting 
the  basement  membrane,  d.  Small 
blood-vessel.] 


mucus  for  the  protection  of  the  membrane.  For  in  the  Pig,  in  which  the 
limitation  of  the  two  kinds  of  glands  to  particular  regions  of  the  stomach  (the 
former  to  the  great  curvature  and  the  middle  portion,  the  latter  to  the  pyloric 
portion,)  is  well  marked,  it  has  been  found  by  the  experiments  of  Zoll  and  Kolli- 
ker,  that  only  the  follicles  with  lobular  cells  furnish  a  fluid  possessing  an  acid 


FIG.  25. 


Appearance  of  the  lining  membrane  of  the  Stomach,  in  an  injected  preparation  ;  —  A, 
from  the  convex  surface  of  the  rugae; — B,  from  the  neighbourhood  of  the  pylorus,  where 
the  orifices  of  the  gastric  follicles  occupy  the  interspaces  of  the  deepest  portions  of  the 
vascular  network. 

reaction  and  a  solvent  power  for  protein-compounds,  the  secretion  of  the  follicles 
lined  by  cylinder-epithelium  being  destitute  of  both  these  properties,  but  agree- 
ing with  ordinary  mucus.  It  appears,  moreover,  that  whilst  the  cylinder-epithe- 
lium is  continually  in  course  of  exuviation  and  renewal  (the  coating  of  mucus 


GASTRIC    DIGESTION. 


107 


being  apparently  furnished  by  the  disintegration  of  its  cells),  the  glandular  epi- 
thelium is  more  permanent;  the  peculiar  contents  of  its  cells  being  probably 
drawn-in  by  them  from  the  surrounding  blood,  and  being  discharged  by  transu- 
dation  into  the  central  passage  of  each  caecum,  without  any  frequent  renewal  of 
the  cells  themselves.1  According  to  M.  Cl.  Bernard,  when  the  stomach  is  empty, 
the  cylindrical  epithelium  which  lines  them  completely  blocks-up  their  orifices 
(Fig.  24),  so  that  during  fasting  these  appear  as  slightly-prominent  papillae  ;  but 
when  the  secretion  of  gastric  fluid  commences,  this 
epithelium  is  cast-forth  by  the  pressure  from  beneath.2 
[In  the  production  of  these  secreting  cells  minute 
granules  appear  to  be  generated  at  the  deeper  part 
of  each  gland ;  two  or  more  of  these  granules,  group- 
ing together,  form  nuclei,  and  are  developed  into  nu- 
cleated cells.  In  those  parts  of  the  gland  which  are 
nearest  to  the  free  surface,  secondary  cells  are  deve- 
loped without  the  primary  ones ;  the  walls  of  the 
latter  then  appear  to  coalesce  and  form  the  proper 
membrane  of  the  gland,  while  the  new  generation  of 
cells,  filled  with  gastric  fluid,  are  discharged  and 
mixed  with  the  food  in  the  stomach  (Fig.  26). 

According  to  Bernard,  the  elaboration  of  the  gastric 
fluid  in  these  cells  seems  to  be  completed  only  when 
they  reach  the  surface,  for,  according  to  this  observer, 
the  mucous  membrane  is  not  acid  a  little  below  the 
surface.  It  has  been  suggested  by  Dr.  Brown- 
Sequard,  however,  that  these  glands  may  be  con- 
cerned in  the  elaboration  of  some  other  constituent  of 
the  gastric  juice — the  pepsin,  for  instance ;  while  the 
acid  constituents  are  developed  by  some  of  the  other 
follicles  that  stud  the  mucous  membrane  of  the 
stomach. —  ED.]  The  interior  surface  of  the  sto- 
mach, though  thrown  by  contraction  when  the  viscus 
is  empty  into  irregular  folds  or  rugae  (Fig.  25,  A),  is 
destitute  of  those  villous  prolongations  which  are  so 
peculiarly  characteristic  of  the  mucous  surface  of  the 
intestines;  near  the  pyloric  orifice,  however,  rudimentary  villi  present  them- 
selves (u).3  [Mr.  Erasmus  Wilson4  has  recently  described  the  mucous  membrane 
of  the  alimentary  canal  as  presenting  two  apparent  differences  of  structure,  to 
which  have  been  applied  the  names  reticulated  and  villous.  The  villous  pro- 
longations are  seen  in  Fig.  32.  The  reticulated  is  so  named,  from  presenting  a 
surface  made  up  of  small  cells,  the  walls  of  which  are  formed  by  prominences  on 
its  surface,  and  not  depressions,  as  usually  described;  the  prominences  corre- 
sponding with  the  villous  prolongations,  and  the  floor  of  the  cells  with  the 
ground  surface  of  the  membrane  (Figs.  27  and  31).  An  analogous  structure  is 
seen  in  the  reticulum,  or  honey-comb  stomach  of  the  ruminant. 

In  the  stomach,  Mr.  Wilson  describes  the  reticular  arrangement  as  extending 
over  its  whole  surface,  in  this  particular  differing  from  the  observations  of  Dr. 
Neill,  who  has  pointed  out  the  reticular  appearance,  as  found  most  distinctly  in 
the  cardiac  end  (thus  suggesting  an  analogy  with  the  ruminant),  while  towards 
the  central  portion,  and  in  the  pyloric  extremity,  the  walls  of  the  cells  become 

1  The  best  account  of  the  structure  of  the  mucous  membrane  of  the  stomach,  and  of  the 
gastric  glands,  is  given  by  Messrs.  Todd  and  Bowman,  "Physiological  Anatomy,"  vol.  ii. 
pp.  190  et  seq.;  and  by  Prof.  Kolliker,  "  Mikroskopische  Anatomic,"  band  ii.  \  163. 

3  "Gazette  MeMicale,"  Mars,  1848. 

3  This  fact  was  first  brought  into  prominent  notice  by  Dr.  Neill,  in  his  Memoir  "  On 
the  Structure  of  the  Mucous  Membrane  of  the  Human  Stomach,"  in  the  "Amer.  Journ.  ct 
Med.  Sci.,"  Jan.,  1851. 

4  [London  Med.  Times  and  Gaz.,  Feb.  3,  1855.] 


One  of  the  tubular  follicles 
of  the  pig's  stomach,  after  Was- 
mann,  cut  obliquely,  so  as  to 
display  the  upper  part  ef  the 
cavity,  with  the  cylindrical 
epithelium  forming  its  walls. 
At  the  lower  part  of  the  folli- 
cle, the  external  nucleated  ex- 
tremities of  the  cylinders  of 
epithelium  are  seen.] 


108  OF    FOOD,     AND     THE     DIGESTIVE     PROCESS. 

converted  into  villous  prolongations  (Fig. 
25).  The  depth  of  the  septa,  or  in  other 
words  the  projection  of  the  reticular  frame, 
is  about  gjfl  of  an  inch,  and  their  breadth, 
that  is  the  thickness  of  the  septa  divested 
of  epithelium,  is  about  J-QQ-Q  of  an  inch. 
In  structure  the  reticulum  is  composed  of 
a  fold  of  the  limitary  membrane,  contain- 
ing the  transparent  granular  substance  of 
A  portion  of  the  mucous  membrane  of  gurface  of  the  CQrium  and  &  lexug  f  the 
the  stomach  magnified  seventy-five  times.  -n  ,  rr,  .,,  r  ,, 

The  alveoli  measured  ^  of  an  inch  in  capillary  vessels.     The  capillary  plexus  of 

length,  by  40-  in  breadth ;  th«  width  of  the  reticulum  is  single,  a  disposition  which 

the  septa  being  J^TF  of  an  inch-     The  Proba%  determines  the  thickness  of   the 

smaller  alveoli  measured  3^  of  an  inch  in  septa.     Its  meshes  are  large  and  open,  and 

length,  and  3^0  *n  breadth.    The  trifid  or  the  vessels  flexuous  and  serpentine  in  their 

quadrifid  division  of  a  small  artery  is  seen  course.        The     border    of     the     septum    is 

at  the  bottom  of  each  alveolus,  and  in  the  formed    b           capillary  vessel,  which   some- 

depressions   between   the  divisions   of  the  .                  J                            •   i         v         • 

artery,  the  apertures  of  the  gastric  folli-  times     runs    m     »    Straight     direction,     and 

cles;  two,  three,  or  four  in  each  depression.]  forms   an    even    rim    to    the   mouth    of    the 

alveoli,  like  that  of  a  honey-comb,  some- 
times forms  abrupt  curves  and  loops,  which  project  before  them  the  limitary 
membrane  and  give  rise  to  flat  papillae.  These  flat  papillae  are  chiefly  found 
at  the  angles  of  the  reticulum,  and  their  existence  in  numbers  gives  a  fringed 
appearance  to  the  rims  of  the  alveoli.  At  the  bottom  of  the  reticulum  are  seen 
the  orifices  of  the  gastric  follicles,  generally  three  in  number.  The  openings  of 
the  gastric  follicles  are  described  by  Mr.  Wilson  as  being  oval  in  shape,  about 
Y^Q 3  of  an  inch  in  diameter,  and  disposed  irregularly  in  the  foveolae,  which  are 
formed  by  the  rete  of  capillary  vessels  in  the  floor  of  the  alveolus,  two  or  three 
in  each ;  so  that  the  entire  number  of  gastric  follicles  opening  into  each  alveolus 
would  amount  to  from  six  to  twelve. 

In  regard  to  the  seat  of  secretion  of  gastric  juice,  M.  Bernard's  experiments 
show  that  it  is  mainly  in  the  pyloric  extremity  of  the  stomach,  as  proved  by  the 
following  experiment.  On  introducing  into  the  jugular  vein  of  one  side  some 
cyanide  of  potash,  and  into  the  other  the  proto-sulphate  of  iron,  both  in  solution, 
they  pass  through  the  circulation  without  combining;  the  absence  of  combination, 
as  he  believes,  depending  upon  the  presence  of  the  albumen  in  the  blood.  Should 
atmospheric  air  be  present,  however,  or  the  albumen  be  destroyed,  the  combination 
takes  place  immediately,  and  the  prussiate  of  iron  is  formed.  In  the  free  secre- 
tions, one  of  the  conditions  of  combination  is  supplied  when  atmospheric  air  is 
present.  M.  Bernard  observed,  on  examining  the  stomach  of  a  dog,  into  whose 
jugulars  he  had  injected  the  solutions  above  mentioned,  that  the  mucous  membrane 
of  the  stomach  was  of  the  normal  colour,  except  near  the  pylorus  and  over  the 
hepatic  portion,  where  it  was  of  the  deep  blue  of  the  prussiate  of  iron;  the  result 
of  the  union  of  the  two  substances  in  the  gastric  juice  as  it  was  poured  out. — ED.1] 

95.  The  nature  and  composition  of  the  Gastric  Juice  which  is  secreted  and 
poured-forth  by  the  peptic  follicles,  have  been  the  subjects  of  much  discussion 
among  Chemists;  and  though  certain  points  may  be  considered  as  satisfactorily 
determined,  there  are  others  which  still  remain  doubtful. —  This  liquid,  when  ob- 
tained without  admixture  with  saliva,  is  clear,  transparent,  colourless,  or  slightly 
yellow,  and  has  very  little  viscidity.  Microscopic  examination  indicates  the  per 
sistence  of  a  few  of  the  cells  exuviated  from  the  interior  of  the  gastric  follicles ; 
but  these  for  the  most  part  leave  no  other  traces  than  their  nuclei  and  a  fine 
molecular  matter  arising  from  their  disintegration.  The  proportion  of  solid  matter 
which  the  Gastric  Juice  contains,  and  the  proportion  which  its  chief  organic  con- 
stituent—  the  pepxin  or  '  gastric  ferment'  —  bears  to  the  inorganic  residue,  seem 
to  vary  greatly  in  different  animals.  The  following  table  gives  the  average  drawr 
1  Donaldson  on  Bernard's  recent  discoveries,  Amer.  Jour.  Med.  Sci.,  Oct.  1851. 


SOLVENT  POWER  OF  GASTRIC  JUICE. 


109 


by  Hubbenet  (a  pupil  of  Bidder  and  Schmidt)  from  his  analyses  of  the  gastric 
fluid  of  the  Dog  and  Sheep,  and  that  of  Gruenewaldt  and  Schrceder1  from  two 
analyses  of  Human  gastric  juice  :  — 


Dog  A, 
without 
saliva. 

DogE, 
mixed  with 
saliva. 

Sheep, 
mixed  with 
saliva. 

Man, 
mixed  with 
saliva. 

973-062 

971-171 

986-147 

994-404 

26-938 

28-829 

13,853 

5-596 

17-127 

17-336 

4-055 

3-195 

9-811 

11-493 

9-798 

2-401 

Free  Hydrochloric  acid  

0-200 

Chloride  of  potassium  

3-050 

2-377 

1-234 

0-550 

1-125 

1-073 

1-518 

1-464 

Chloride  of  calcium      

2-507 

3-147 

4-369 

0-062 

Chloride  of  ammonium  

0-624 

1-661 

0-114 

0-468 

0  537 

0-473 

1 

Phosphate  of  magnesia  

1-729 

2-^94 

1-182 

0-226 

0-323 

0-577 

i    0-125 

Potass  united  with  organic  mat- 
ters           .  •        .... 

0-082 

0-121 

0-331 

J 

96.  The  most  characteristic  feature  of  the  Gastric  Juice  is  its  decided  acidity, 
which  is  very  perceptible  to  the  taste.  With  regard  to  the  nature  of  the  acid, 
however,  there  has  been  much  discrepancy  of  opinion  amongst  Chemists;  for, 
simple  as  the  problem  of  its  determination  might  seem,  yet  it  is  complicated  by 
the  very  peculiar  property  which  lactic  acid  possesses,  of  decomposing  the  alkaline 
chlorides  at  a  certain  elevation  of  temperature,  the  degree  being  partly  determined 
by  the  strength  of  the  solution.  Hence,  supposing  lactic  acid  to  be  present  in 
the  stomach  with  chloride  of  sodium,  the  fluid  which  passes-over  by  distillation 
will  at  first  be  destitute  of  hydrochloric  acid ;  but,  as  the  liquor  becomes  more 
concentrated,  and  the  temperature  rises,  hydrochloric  acid  will  appear.  This,  it 
has  been  alleged  by  Bernard,  R.  D.  Thomson,  Lehmann,  and  other  Chemists,  is 
the  true  source  of  the  Hydrochloric  acid  which  may  be  always  obtained  from  the 
gastric  juice  by  this  method ;  and  it  is  affirmed  by  them  that  Lactic  acid  is  the 
real  agent  in  the  solvent  process  to  which  that  fluid  is  subservient,  the  presence 
of  free  lactic  acid  in  the  stomach  having  been  determined  by  other  means.  But 
however  true  this  conclusion  may  be  in  regard  to  dogs  and  pigs,  which  are  the 
animals  that  have  been  chiefly  experimented-on  for  this  purpose,  it  is  question- 
able how  far  it  is  fairly  applicable  to  Man.  In  the  first  place,  the  great  readiness 
with  which  hydrochloric  acid  was  obtained  by  Prof.  Dunglison  from  the  pure 
gastric  fluid  drawn  from  the  stomach  of  Alexis  St.  Martin,  and  the  fact  that  the 
smell  of  hydrochloric  acid  might  be  distinctly  recognized  in  the  fresh  juice,2  are 
strong  evidences  in  favour  of  the  belief  that  (as  originally  maintained  by  Dr. 
Prout)  free  hydrochloric  acid  is  present  in  this  fluid,  and  that  it  is  the  principal 
if  not  the  only  source  of  its  acidity.  And  an  opportunity  having  been  afforded 
to  Dr.  Bence  Jones,  of  obtaining  a  fluid  continually  vomited  in  large  quantities 
from  the  stomach  of  a  patient  affected  with  Sarcina  ventriculi,  and  this  fluid, 
which  presented  all  the  ostensible  characters  of  Gastric  juice,  having  been  placed 
in  the  hands  of  Prof.  Graham  for  examination,  this  distinguished  Chemist  ha? 
succeeded  in  separating  hydrochloric  acid  from  it  by  his  method  of  f  liquid  diffu- 
sion,' which  is  not  open  to  the  objection  that  applies  to  distillation;  and  although 
he  has  found  free  lactic  acid  to  be  also  present,  its  quantity  is  comparatively 

1  "  Svicci  Gastrici  Humani  Indoles,"  &c.,  Dissert.  Inaug.  Dorpati.,  1853. 
a  See  Prof.  Dunglison's  "Human  Physiology,"  7th  edit.,  vol.  i.  pp.  585 — 6. 


110  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

small.2  The  truth  appears  to  be,  that  both  the  hydrochloric  and  lactic  acids  may 
give  to  the  gastric  fluid  the  peculiar  solvent  power,  which  (as  will  be  presently 
shown)  it  possesses  for  albuminous  substances,  and  that  one  may  take  the  place 
of  the  other;  so  that  whilst  in  Man,  hydrochloric  acid  is  the  chief  source  of  the 
acidity,  lactic  acid  may  be  so  in  the  dog  and  pig.  Acetic,  butyric,  and  phos- 
phoric acids  have  also  been  occasionally  met-with  in  the  gastric  fluid;  but  they 
can  scarcely  be  reckoned  among  its  normal  constituents. 

97.  The  peculiar  organic  'ferment'  of  the  Gastric  juice,  to  which  the  name 
of  Pepsin  has  been  given,  was  first  obtained  in  an  isolated  state  by  Wasmann ; 
who  has  given  the  following  account  of  the  properties  and  reactions  of  that  which 
he  procured  from  the  mucous  membrane  of  the  stomach  of  the  Pig,  which  greatly 
resembles  that  of  Man.  When  this  membrane  is  digested  in  a  large  quantity  of 
water  at  from  85°  to  95°,  many  other  matters  are  removed  from  it  besides  pepsin; 
but  if  this  water  be  poured-off,  and  the  digestion  be  continued  with  fresh  water 
in  the  cold,  very  little  but  pepsin  is  then  taken-up.  Pepsin  appears  to  be  but 
sparingly  soluble  in  water;  when  its  solution  is  evaporated  to  dryness,  there 
remains  a  brown,  greyish,  viscid  mass,  with  the  odour  of  glue,  and  having  tho 
appearance  of  an  extract.  The  solution  of  this  in  water  is  turbid,  and  still  pos- 
sesses a  portion  of  the  characteristic  power  of  pepsin,  but  greatly  reduced. 
When  strong  alcohol  is  added  to  a  fresh  solution  of  pepsin,  the  latter  is  precipi- 
tated in  white  flocks,  which  may  be  collected  on  a  filter,  and  produce  a  grey  compact 
mass  when  dried.  Pepsin  enters  into  chemical  combination  with  many  acids, 
forming  compounds  which  still  redden  litmus  paper;  and  it  is  when  thus  united 
with  acetic  and  muriatic  acids,  that  its  solvent  powers  are  the  greatest.3  [Pepsin 
resembles  albumen,  as  stated  by  Robin  and  Verdeil,  in  being  coagulated  by  heat ; 
and  Dr.  Dalton  asserts  that  Lehmann  and  Frerichs  are  certainly  in  error  when 
they  declare  the  contrary;  an  error  into  which  they  have  perhaps  been  led 
by  regarding  as  true  gastric  juice  an  unnatural  fluid,  obtained  by  irritating  the 
stomach  with  indigestible  substances,  pebbles,  pepper-corns,  &c.  The  coagulum 
thrown  down  on  boiling  fresh  gastric  juice  is  not  albumen,  as  Lehmann  intimates, 
since  it  is  not  precipitated  by  either  nitric  acid,  or  ferrocyanide  of  potassium ; 
and  after  gastric  juice  has  been  boiled  and  filtered,  it  has  lost  its  digestive  power, 
though  its  acid  reaction  still  remains.  ED.]  —  The  general  result  of  later  re- 
searches has  been  to  confirm  the  views  laid  down  in  the  following  statement  of 
Wasmann's  inquiries.  "  In  regard  to  the  solvent  power  of  pepsin  for  coagulated 
albumen,  it  was  observed  by  M.  Wasmann,  that  a.  liquid  which  contains 
17-10, OOOths  of  acetate  of  pepsin,  and  6  drops  of  hydrochloric  acid  per  ounce, 
possesses  a  very  sensible  solvent  power,  so  that  it  will  dissolve  a  thin  slice  of 
coagulated  albumen  in  the  course  of  6  or  8  hours'  digestion.  With  12  drops  of 
hydrochloric  acid  per  ounce,  the  white  of  egg  is  dissolved  in  2  hours.  A  liquid 
which  contains  £  gr-  of  acetate  of  pepsin,  and  to  which  hydrochloric  acid  and 
white  of  egg  are  alternately  added,  so  long  as  the  latter  dissolves,  is  capable  of 
taking  up  210  grains  of  coagulated  white  of  egg  at  a  temperature  between  95° 
and  104°.  It  would  appear,  from  such  experiments,  that  the  Hydrochloric  acid 

1  For  his  knowledge  of  this  fact,  the  Author  is  indebted  to  Prof.  Graham. —  That  Hydro- 
chloric acid  is  the  source  of  the  acidity  of  the  gastric  juice  has  also  been  maintained  by 
Enderlin  ("Canstatt's  Jahresberioht,"  1843,  p.  149),  and  recently  by  Hiibbenet  ("Disqui- 
sitiones  de  Succo  Gastrico,"  diss.  inaug.,  Dorpat,  1850),  by  Bidder  and  Schmidt  ("Die 
Verdauungssaefte  und  der  Stoffwechsel"),  and  by  Gruenewaldt  and  Schroeder  in  their 
Theses  just  cited. 

3  It  has  been  supposed  by  Prof.  Schmidt  (of  Dorpat),  that  the  union  of  pepsin  with  these 
and  other  acids  forms  a  '  conjugated  acid,'  which  possesses  the  property  of  forming  soluble 
compounds  with  albuminous  and  other  azotized  substances ;  but  the  existence  of  such  an 
acid  has  not  been  determined  by  the  analysis  of  any  combination  either  with  a  mineral 
base  or  with  an  albuminous  substance ;  and  the  numerous  experiments  which  have  been 
made  by  Prof.  Lehmann  regarding  the  digestive  agents  and  substances  to  be  digested  indi- 
cate no  such  definite  proportion  between  them,  as  this  view  of  the  constitution  of  the  former 
would  require. 


GASTRIC    DIGESTION.  Ill 

is  the  true  solvent,  and  that  the  action  of  the  Pepsin  is  limited  to  that  of  dis- 
posing the  white  of  egg  to  dissolve  in  hydrochloric  acid.  The  acid  when  alone 
dissolves  white  of  egg  by  ebullition,  just  as  it  does  under  the  influence  of  pepsin ; 
from  which  it  follows  that  pepsin  replaces  the  effect  of  a  high  temperature,  which 
is  not  possible  in  the  stomach.  The  same  acid  with  pepsin  dissolved  blood,  fibrin, 
meat  and  cheese;  while  the  isolated  acid  dissolved  only  an  insignificant  quantity 
at  the  same  temperature  ;  but  when  raised  to  the  boiling  point,  it  dissolved  nearly 
as  much,  and  the  part  dissolved  appeared  to  be  of  the  same  nature.  The  epi- 
dermis, horn,  the  elastic  tissue  (such  as  the  fibrous  membrane  of  arteries)  do  not 
dissolve  in  a  dilute  acid  containing  pepsin.  M.  Wasmann  has  remarked  that  the 
pepsin  of  the  stomach  of  the  pig  is  entirely  destitute  of  the  power  to  coagulate 
milk,  although  the  pepsin  of  the  stomach  of  the  calf  possesses  it  in  a  very  high 
degreee;  from  which  he  is  led  to  suppose  that  the  power  of  the  latter  depends 
upon  a  particular  modification  of  pepsin,  or  perhaps  upon  another  substance  ac- 
companying it,  which  ceases  to  be  formed  when  the  young  animal  is  no  longer 
nourished  by  the  milk  of  its  mother/" 

98.  It  is  only  when  either  alimentary  or  some  other  substances  capable 
of  exciting  irritation,  are  present  in  the  stomach,  that  this  acid  secretion 
is  poured  forth.  So  long  as  it  is  empty,  the  secretion  which  moistens  its 
walls  is  neutral  or  even  alkaline ;  but  as  soon  as  food  is  taken,  acid  is 
poured  forth,  and  this  in  increasing  quantities,  until  a  certain  time  after 
the  commencement  of  the  digestive  process,  when  the  acidity  of  the  stomach 
is  at  its  maximum.  In  proportion  as  the  alimentary  matter  is  dissolved, 
however,  and  is  either  at  once  absorbed,  or  escapes  through  the  pyloric 
orifice,  the  acidity  of  the  stomach  diminishes ;  and  as  soon  as  its  cavity  is 
emptied,  the  secretion  of  its  walls  is  neutral  again.2  The  quantity  of  fluid  thus 
poured-forth  from  the  walls  of  the  stomach,  may  be  approximately  estimated  from 
the  amount  of  albuminous  matter  known  to  be  dissolved  by  it;  but  the  result 
must  depend  upon  the  solvent  power  which  it  is  assumed  to  possess.  And  thus, 
whilst  Lehmann  considers  that  four  pounds  daily  would  suffice,  it  is  asserted  by 
Bidder  and  Schmidt  that  from  fourteen  to  seventeen  pounds'dailj  will  be  required. 
[In  the  excellent  paper  of  Prof.  Dalton,  before  quoted,  is  detailed  the  method  of 
determining  the  quantity  of  albuminoid  matter  dissolved  by  the  gastric  juice.  It 
was  first  ascertained  that  the  fresh  lean  meat  of  a  bullock's  heart  loses  by  desic- 
cation 78  per  cent  of  its  weight ;  300  grains  of  such  meat,  cut  into  small  pieces, 
were  then  digested  for  ten  hours  in  3iss  of  gastric  juice  at  100  F.,  the  mixture 
being  gently  agitated  as  often  as  every  hour.  The  meat  remaining  undissolved 
was  then  collected  on  a  previously-weighed  filter  and  evaporated  to  dryness. 
When  perfectly  dry,  it  weighed  55  grains.  This  represented,  allowing  for  loss 
by  evaporation,  250  grains  of  the  meat  in  its  natural  moist  condition ;  50  grains 
of  meat  were  then  dissolved  by  3iss  of  gastric  juice,  or  a  little  over  30  grains  per 
ounce. 

From  these  data,  it  is  further  stated,  we  can  form  some  idea  of  the  large  quan- 
tity of  gastric  juice  secreted  during  the  process  of  digestion.  One  pound  of  raw 
meat  is  only  a  moderate  meal  for  a  medium-sized  dog,  and  yet  to  dissolve  this 
quantity  (supposing  the  whole  of  it  to  be  digested),  no  less  than  sixteen  pints  of 
gastric  juice  will  be  necessary.  This  quantity,  or  any  approximation,  would  be 
altogether  incredible,  if  we  did  not  recollect  that  the  gastric  juice,  as  soon  as  it 
has  dissolved  its  quota  of  food,  is  immediately  reabsorbed,  and  enters  the  circula- 
tion with  the  alimentary  substances  which  it  holds  in  solution ;  so  that  a  very 
large  quantity  of  the  secretion  may  be  poured  out  during  the  digestion  of  a  meal, 
at  an  expense  to  the  blood,  at  any  one  time,  of  only  two  or  three  ounces  of  fluid 
The  simplest  investigation  shows  that  the  gastric  juice  does  not  accumulate  in  the 

1  Prof.  Graham's  "Elements  of  Chemistry,"  pp.  1031-1030. 

2  See  Dr.  Bence  Jones,  in  "  Medical  Times,"  June  14,  1852. 


112  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

stomach  in  any  considerable  quantity,  to  remain  there  until  the  solution  of  all  the 
food  has  been  accomplished,  but  that  it  is  gradually  secreted  so  long  as  any  food 
remains  undissolved ;  that  portion  which  has  been  already  digested  being  disposed 
of  by  reabsorption  with  its  solvent  fluid.  There  is  then,  during  digestion,  a  con- 
stant circulation  of  gastric  juice  from  the  vessels  of  the  stomach,  and  from  the 
stomach  back  again  to  the  vessels.  Or,  perhaps,  as  the  author  further  remarks, 
it  would  be  more  correct  to  say,  that  it  is  only  the  watery  portions  of  the  juice, 
holding  sometimes  in  solution  the  digested  albumen  and  albuminose,  that  perform 
this  circulation  j  while  its  acid  and  organic  ingredients  remain,  very  possibly,  in 
the  stomach,  ready  to  act  on  a  new  quantity  of  food,  as  that  which  has  been 
already  digested  is  withdrawn  by  absorption.  That  this  is  really  the  case  is  de- 
clared to  be  proved  by  the  following  facts.  First,  if  a  dog  be  killed  some  hours 
after  taking  a  meal,  there  is  never  more  than  a  very  small  quantity  of  fluid  found 
in  the  stomach,  just  sufficient  to  penetrate  and  smear  over  the  half-digested  pieces 
of  meat;  and  secondly,  in  the  living  animal,  gastric  juice,  drawn  from  the  sto- 
mach when  digestion  of  meat  has  been  going  on  for  six  hours,  contains  little  or 
no  more  organic  matter  in  solution  than  that  extracted  fifteen  to  thirty  minutes 
after  the  introduction  of  food.  It  has  evidently  been  freshly  secreted ;  and,  in 
order  to  obtain  gastric  juice  saturated  with  alimentary  matter,  it  must  be  artifi- 
cially digested  with  food  in  test-tubes,  where  this  constant  absorption  and  reno- 
vation cannot  take  place.  —  ED.] 

99.  A  very  important  series  of  observations  on  the  conditions  under  which  the 
Gastric  juice  is  secreted,  was  made  some  years  since  by  Dr.  Beaumont,  in  the 
remarkable  ease  of  Alexis  St.  Martin,  already  several  times  referred  to.1  "The 
inner  coat  of  the  stomach  (as  seen  through  the  fistulous  orifice)  in  its  natural  and 
healthy  state,  is  of  a  light  or  pale  pink  color,  varying  in  its  hues,  according  to  its 
full  or  empty  state.  It  is  of  a  soft  or  velvet-like  appearance,  and  is  constantly 
covered  with  a  very  thin,  transparent,  viscid  mucus,  lining  the  whole  interior  of 
the  organ.  By  applying  aliment  or  other  irritants,  to  the  internal  coat  of  the 
stomach,  and  observing  the  effect  through  a  magnifying  glass,  innumerable  lucid 
points,  and  very  fine  [nervous  or  vascular]  papillae  can  be  seen  arising  from  the 
villous  membrane,  and  protruding  through  the  mucous  coat,  from  which  distils  a 
pure,  limpid,  colourless,  slightly  viscid  fluid."  (The  papillae  here  described 
appear  to  be  the  orifices  of  the  gastric  follicles,  which  are  usually  closed  by  their 
epithelial  cells  during  fasting,  and  which  would  seem  to  become  prominent  when 
che  vis  a  tergo  of  the  secreted  fluid  first  causes  this  plug  of  cells  to  be  cast  forth.) 
"  The  fluid  thus  excited  is  invariably  distinctly  acid.  The  mucus  of  the  stomach 
is  less  fluid,  more  viscid  or  albuminous,  semi-opaque,  sometimes  a  little  saltish, 
and  does  not  possess  the  slightest  character  of  acidity.  The  gastric  fluid  never 
appears  to  be  accumulated  in  the  cavity  of  the  stomach  while  fasting ;  and  is  sel- 
dom, if  ever,  discharged  from  its  proper  secerning  vessels,  except  when  excited 
by  the  natural  stimulus  of  aliment,  mechanical  irritation  of  tubes,  or  other  ex- 
citants. When  aliment  is  received,  the  juice  is  given  out  in  exact  proportion  to 
its  requirements  for  solution,  except  when  more  food  has  been  taken  than  is 
necessary  for  the  wants  of  the  system."  —  The  observations  of  Dr.  Beaumont 
have  been  confirmed  by  those  of  M.  Blondlot1  and  of  M.  Cl.  Bernard,2  which 
were  made  upon  Dogs  in  whose  stomachs  fistulous  openings  were  maintained  for 
a  length  of  time.  They  found  that  the  flow  of  gastric  fluid  is  more  excited  by 
pepper,  salt,  and  soluble  stimulants,  than  it  is  by  mechanical  irritation ;  and  that 
if  mechanical  irritation  be  carried  beyond  certain  limits,  so  as  to  produce  pain, 
the  secretion,  instead  of  being  more  abundant,  diminishes  or  ceases  entirely  j 
whilst  a  ropy  mucus  is  poured-out  instead,  and  the  movements  of  the  stomach 

1  See  Dr.  Beaumont's  "  Experiments  and  Observations   on  the   Gastric  Juice  and  the 
Physiology  of  Digestion,"  reprinted  with  notes,  by  Dr.  Andrew  Combe,  Edinb.,  1838. 
1  "  Traits'  Analytique  de  la  Digestion." 
•  "  Archiv.  d'Anat.  Gen.  et  de  Physiol.,"  Jan.  1846. 


CONDITIONS  OF  SECRETION  OF  GASTRIC  JUICE.    113 

are  considerably  increased.     The  animal  at  the  same  time  appears  ill  at  case,  is 
agitated,  has  nausea,  and,  if  the  irritation  be  continued,  actual  vomiting;  and 
bile  has  been  observed  to  flow  into  the  stomach,  and  escape  by  the  fistulous  open- 
ing.    Similar  disorders  of  the  functions  of  the  stomach  result  from  violent  pain 
in  other  parts  of  the  body ;  the  process  of  digestion  in   such  cases  being  sus- 
pended, and  sometimes  vomiting  excited.     When  acidulated  substances,  as  food 
rendered  acid  by  the  addition  of  a  little  vinegar,  were  introduced  into  the  stomach, 
the  quantity  of  gastric  fluid  poured-out  was  much  smaller,  and  the  digestive  pro- 
cess consequently  slower,  than  when  similar  food,  rendered  alkaline  by  a  weak 
solution  of  carbonate  of  soda,  was  introduced.     If,  however,  instead  of  a  weak 
solution,  carbonate  of  soda  in  crystal  or  in  powder  was  introduced  into  the  sto- 
mach, a  large  quantity  of  mucus  and  bile,  instead  of  gastric  fluid,  flowed  into  the 
stomach  ;  and  vomiting  and  purging  very  often  followed.     When  very  cold  water, 
or  small  pieces  of  ice,  were  introduced  into  the  stomach,  the  mucous  membrane 
was  at  first  rendered  very  pallid ;  but  soon  a  kind  of  reaction  followed,  the  mem- 
brane became  turgid  with  blood,  and  a  large  quantity  of  gastric  fluid  was  secreted. 
If,  however,  too  much  ice  was  employed,  the  animal  appeared  ill,  and  shivered  ; 
and  digestion,  instead  of  being  rendered  more  active,  was  retarded.     Moderate 
heat,  applied  to  the  mucous  surface  of  the  stomach,  appeared  to  have  no  particular 
action  on  digestion ;   but  a  high  degree  of  heat  produced  most  serious  conse- 
quences.    Thus  the  introduction  of  a  little  boiling  water  threw  the  animal  at 
once  into  a  kind  of  adynamic  state,  which  was  followed  by  death  in  three  or  four 
hours ;  the  mucous  membrane  of  the  stomach  was  found  red  and  swollen,  whilst 
an  abundant  exudation  of  blackish  blood  had  taken  place  into  the  cavity  of  the 
organ.     Similar  injurious  effects  resulted  in  a  greater  or  less  degree,  from  the 
introduction  of  other  irritants,  such  as  nitrate  of  silver  or  ammonia ;  the  digestive 
functions  being  at  once  abolished,  and  the  mucous  surface  of  the  organ  rendered 
highly  sensitive. 

100.  That  the  quantity  of  the  Gastric  Juice  secreted  from  the  walls  of  the 
stomach  depends  rather  upon  the  general  requirements  of  the  system,  than  upon 
the  quantity  of  food  introduced  into  the  digestive  cavity,  is  a  principle  of  the 
highest  practical  importance,  and  cannot  be  too  steadily  kept  in  view  in  Dietetics. 
A  definite  proportion  only  of  aliment  can  be  perfectly  digested  in  a  given  quan- 
tity of  the  fluid ;  the  action  of  which,  like  other  chemical  operations,  ceases  after 
having  been  exercised  on  a  fixed  and  definite  amount  of  matter.  "  When  the 
juice  has  become  saturated,  it  refuses  to  dissolve  more ;  and,  if  an  excess  of  food 
has  been  taken,  the  residue  remains  in  the  stomach,  or  passes  into  the  bowels  in 
a  crude  state,  and  becomes  a  source  of  nervous  irritation,  pain,  and  disease,  for  a 
long  time."  The  unfavourable  effect  of  an  undue  burthen  of  food  upon  the 
Stomach  itself,  interferes  with  its  healthy  action  ;  and  thus  the  quantity  really 
appropriate  is  not  dissolved.  The  febrile  disturbance  is  thus  increased;  and  the 
mucous  membrane  of  the  stomach  exhibits  evident  indications  of  its  morbid  con- 
dition. The  description  of  these  indications  given  by  Dr.  Beaumont,  i&  peculiarly 
graphic,  as  well  as  hygienically  important.  "  In  disease,  or  partial  derangement 
of  the  healthy  function,  the  mucous  membrane  presents  various  and  essentially- 
different  appearances.  In  febrile  conditions  of  the  system,  occasioned  by  what- 
ever cause, —  obstructed  perspiration,  undue  excitement  by  stimulating  liquors, 
overloading  the  stomach  with  food,  fear,  anger,  or  whatever  depresses  or  disturbs 
the  nervous  system,  —  the  villous  coat  becomes  sometimes  red  and  dry,  at  other 
times  pale  and  moist,  and  loses  its  smooth  and  healthy  appearance;  the  secretions 
become  vitiated,  greatly  diminished,  or  even  suppressed ;  the  coat  of  mucus 
scarcely  perceptible,  the  follicles  flat  and  flaccid,  with  secretions  insufficient  to 
prevent  the  papillae  from  irritation.  There  are  sometimes  found,  on  the  internal 
coat  of  the  stomach,  eruptions  of  deep-red  pimples,  not  numerous,  but  distributed 
here  and  there  upon  the  villous  membrane,  rising  above  the  surface  of  the  mucous 
coat.  These  are  at  first  sharp-pointed,  and  red,  but  frequently  become  filled  with 
8 


114  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

white  purulent  matter.  At  other  times  irregular,  circumscribed  red  patches, 
varying  in  size  and  extent  from  half  an  inch  to  an  inch  and  a  half  in  circumfe- 
rence, are  found  on  the  internal  coat.  These  appear  to  be  the  effects  of  conges- 
tion in  the  minute  blood-vessels  of  the  stomach.  There  are  also  seen  at  times 
small  aphthous  crusts,  in  connection  with  these  red  patches.  Abrasion  of  the 
lining  membrane,  like  the  rolling-up  of  the  mucous  coat  into  small  shreds  or 
strings,  leaving  the  papillae  bare  for  an  indefinite  space,  is  not  an  uncommon  ap- 
pearance. These  diseased  appearances,  when  very  slight,  do  not  always  aifect 
essentially  the  gastric  apparatus.  When  considerable,  and  particularly  when 
there  are  corresponding  symptoms  of  disease, — as  dryness  of  the  mouth,  thirst, 
accelerated  pulse,  &c. —  no  gastric  juice  can  be  extracted  l>y  the  alimentary  stim- 
ulus. Drinks  are  immediately  absorbed  or  otherwise  disposed-of;  but  food  taken 
iu  this  condition  of  the  stomach  remains  undigested  for  twenty-four  or  forty-eight 
hours,  or  more,  increasing  the  derangement  of  the  alimentary  canal,  and  aggra- 
vating the  general  symptoms  of  disease.  After  excessive  eating  or  drinking, 
chymificatiori  is  retarded ;  and,  though  the  appetite  be  not  always  impaired  at 
first,  the  fluids  become  acrid  and  sharp,  excoriating  the  edges  of  the  aperture, 
and  almost  invariably  producing  aphthous  patches  and  the  other  indications  of  a 
diseased  state  of  the  internal  membrane.  Vitiated  bile  is  also  found  in  the 
stomach  under  these  circumstances,  and  flocculi  of  mucus  are  more  abundant  than 
in  health.  Whenever  this  morbid  condition  of  the  stomach  occurs,  with  the 
usual  accompanying  symptoms  of  disease,  there  is  generally  a  corresponding  ap- 
pearance of  the  tongue.  When  a  healthy  state  of  the  stomach  is  restored,  the 
tongue  invariably  becomes  clean."1 

101.  That  the  secretion  of  Gastric  Juice  is  affected  in  a  very  marked  manner 
by  conditions  of  the  Nervous  system,  is  indicated  by  the  effect  of  mental  emo- 
tions in  putting  an  immediate  stop  to  the  digestive  process,  when  it  is  going-on 
with  full  vigour.  But  it  is  still  more  conclusively  proved  by  the  effect  of  division 
of  the  Pneumogastric  nerve;  which  almost  instantaneously  checks  the  elaboration 
of  the  fluid.  The  most  satisfactory  evidence  of  the  influence  of  this  operation, 
is  afforded  by  the  experiments  of  M.  Bernard  upon  dogs  in  whose  stomachs  fis- 
tulous  orifices  had  been  established.2  For  when  the  section  was  made  during  the 
free  flow  of  gastric  juice  (through  a  canula  previously  introduced  into  the  sto- 
mach), excited  by  the  presence  of  an  alimentary  bolus,  the  flow  immediately 
ceased,  and  the  mucous  membrane,  which  had  been  tense  and  turgid  the  moment 
before,  became  withered  and  pale.  On  introducing  the  finger  into  the  stomach 
itself,  the  walls  were  perceived  to  be  perfectly  flaccid,  and  there  was  no  longer  the 
gentle  pressure  which  had  been  previously  felt.  The  rapidity  and  completeness  of 
this  influence  are  further  demonstrated  by  the  following  ingenious  experiment,  de- 

1  Dr.  A.  Combe's  commentary  on  the  above  passage  is  too  apposite  to  be  omitted. 
"  Many  persons  who  obviously  live  too  freely,  protest  against  the  fact,  because  they  feel 
no  immediate  inconvenience,  either  from  the  quantity  of  food,  or  the  stimulants  in  which 
they  habitually  indulge ;  or,  in  other  words,  because  they  experience  no  pain,  sickness,  or 
headache,  —  nothing,  perhaps,  except  slight  fulness  and  oppression,  which  soon  go  off. 
Observation  extended  over  a  sufficient  length  of  time,  however,  shows  that  the  conclusion 
drawn  is  entirely  fallacious,  and  that  the  real  amount  of  injury  is  not  felt  at  the  moment, 
merely  because,  for  a  wise  purpose,  nature  has  deprived  us  of  any  consciousness  of  either 
the  existence  or  the  state  of  the  stomach  during  health.  In  accordance  with  this,  Dr. 
Beaumont's  experiments  prove,  that  extensive  erythematic  inflammation  of  the  mucous 
coat  of  the  stomach  was  of  frequent  occurrence  in  St.  Martin  after  excesses  in  eating,  and 
especially  in  drinking,  even  when  no  marked  general  symptom  was  present  to  indicate  its 
existence.  Occasionally  febrile  heat,  nausea,  headache,  and  thirst  were  complained  of, 
but  not  always.  Had  St.  Martin's  stomach,  and  its  inflamed  patches,  not  been  visible  to 
the  eye,  he  too  might  have  pleaded  that  his  temporary  excesses  did  him  no  harm  ;  but, 
when  they  presented  themselves  in  such  legible  characters  that  Dr.  Beaumont  could  not 
miss  seeing  them,  argument  and  supposition  were  at  an  end,  and  the  broad  fact  could  not 
be  denied. 

•  "Gazette  Me*dicale,"  June  1,  1844. 


GASTRIC     DIGESTION.  115 

vised  by  M.  Bernard.  The  two  substances  cmuhin  (the  albuminous  matter  found 
m  almonds)  and  amygdalin  (the  active  principle  of  bitter  almonds)  are  quite  inno- 
cuous when  administered  separately ;  but  when  they  are  united,  a  production  of 
hydrocyanic  acid  takes  place;  so  that,  if  this  should  occur  in  the  stomach  of  an 
animal,  the  poison  proves  fatal,  provided  that  it  be  generated  in  sufficient  quantity. 
If,  however,  the  emulsin  be  given  first,  and  the  amygdalin  half  an  hour  after- 
wards, no  such  result  occurs ;  because  the  properties  of  the  emulsin  are  so  changed 
by  the  gastric  fluid  secreted  during  the  interval,  that  it  no  longer  generates  hydro- 
cyanic acid  with  amygdalin.  But  if  the  emulsin  be  given  to  an  animal  whose 
pneumogastric  nerves  have  been  just  divided,  and  the  amygdalin  be  administered 
half  an  hour  subsequently,  the  effect  is  the  same  as  if  the  two  substances  had 
been  given  at  one  time;  showing  that  no  secretion  of  gastric  fluid  could  have 
taken  place. —  The  first  obvious  effects  of  this  operation,  are  vomiting  (in  animals 
that  are  capable  of  it)  and  loathing  of  food  •  and  the  arrestment  of  the  digestive 
process  is  indicated,  on  post-mortem  examination  some  hours  afterwards,  by  the 
absence  of  any  digestive  change  in  food  that  may  have  been  taken  just  previously 
to  the  operation,  and  that  has  not  been  ejected  from  the  stomach. 

102.  But,  as  was  first  proved  by  Dr.  John  Reid,1  a  re-establishment  of  the  di- 
gestive power  manifests  itself  after  an  interval  of  some  days,  if  the  animals  should 
survive  so  long.  In  the  animals  which  died  within  the  first  four  or  five  days, 
no  indication  of  this  restoration  could  be  discovered  by  Dr.  R.  ;  in  those  which 
survived  longer,  great  emaciation  took  place ;  but  when  life  was  sufficiently  pro- 
longed, the  power  of  assimilation  seemed  almost  completely  restored.  This  was 
the  case  in  four  out  of  the  seventeen  dogs  experimented-on ;  and  the  evidence  of 
this  restoration  consisted  in  the  recovery  of  flesh  and  blood  by  the  animals,  the 
vomiting  of  half-digested  food  permanently  reddening  litmus  paper,  the  disap- 
pearance of  a  considerable  quantity  of  alimentary  matter  from  the  intestinal 
canal,  and  the  existence  of  chyle  in  the  lacteals.  It  may  serve  to  account  in 
some  degree  for  the  contrary  results  obtained  by  other  experimenters,  to  state  that 
seven  out  of  Dr.  R.'s  seventeen  experiments  were  performed,  before  he  obtained 
any  evidence  of  digestion  after  the  operation,  and  that  the  four  which  furnished 
this  followed  one  another  almost  in  succession ;  so  that  it  is  easy  to  understand 
why  those,  who  were  satisfied  with  a  small  number  of  experiments,  should  have 
been  led  to  deny  it  altogether. —  Another  series  of  experiments  was  performed  by 
Dr.  Reid,  for  the  purpose  of  testing  the  validity  of  the  results  obtained  by  Sii 
B.  Brodie,  relative  to  the  effects  of  section  of  the  Par  Vagurn  upon  the  secretions 
of  the  stomach,  after  the  introduction  of  arsenious  acid  into  the  system.  Ac- 
cording to  that  eminent  Surgeon  and  Physiologist,2  when  the  poison  was  intro- 
duced after  the  Pneumogastric  had  been  divided  on  each  side,  the  quantity  of  the 
protective  mucous  and  watery  secretions  was  much  less  than  usual,  although 
obvious  marks  of  inflammation  were  present.  In  order  to  avoid  error  as  much 
as  possible,  Dr.  Reid  made  five  sets  of  experiments,  employing  two  dogs  in  each, 
as  nearly  as  possible  of  equal  size  and  strength,  introducing  the  same  quantity  of 
the  poison  into  the  system  of  each  in  the  same  manner,  but  cutting  the  Vagi  in 
one,  and  leaving  them  entire  in  the  other.  This  comparative  mode  of  experi- 
menting is  obviously  the  only  one  admissible  in  such  an  investigation.  Its  result 
was  in  every  instance  opposed  to  the  statements  of  Sir  B.  Brodie;  the  quantity 
of  the  mucous  and  watery  secretions  of  the  stomach  being  nearly  the  same  in 
each  individual  of  the  respective  pairs  subjected  to  experiment;  so  that  theii 
production  can  no  longer  be  referred  to  the  influence  of  the  Pneumogastric  nerves. 
Moreover,  the  appearances  of  inflammation  were,  in  four  out  of  the  five  cases, 

1  "  Edinb.  Med.  and  Surg.  Journal,"  April,  1839;  and  "Physiological,  Anatomical, 
and  Pathological  Researches,"  CHAP.  v. — Dr.  Reid's  results  have  been  confirmed  as  to  this 
important  particular  by  Hiibbenet  (Op.  cit.),  and  more  recently  by  Bidder  and  Schmidt, 
"111.  Med.  Zeitung,"  1852,  heft  viii.  p.  112. 

a  "Philosophical  Transactions,"  1814,  p.  102. 


116  OF    FOOD,     AND    THE    DIGESTIVE    PROCESS. 

greatest  in  the  animals  whose  Vagi  were  left  entire ;  and  this  seemed  to  be  refer- 
able  to  the  longer  duration  of  their  lives  after  the  arsenic  had  been  introduced. 
The  results  of  Sir  B.  Brodie's  experiments  are  perhaps  to  be  explained  by  the 
speedy  occurrence  of  death  in  the  subjects  of  them,  consequent  (it  may  be)  upon 
the  want  of  sufficiently  free  respiration,  which  was  carefully  guarded  against  by 
Dr.  Reid. 

103.  It  must  be  held  as  demonstrated  by  these  experiments,  then,  that  all  the 
arguments  which  have  been  drawn  from  the  effects  of  lesion  of  the  Pneumogas- 
trics  upon  the  functions  of  the  Stomach,  in  favour  of  the  doctrine  that  Secretion 
depends  upon  Nervous  agency  must  be  set  aside.     That  these  nerves  have  an  im- 
portant influence  on  the  gastric  secretion,  is  evident  from  the  deficiency  in  its 
amount  soon  after  their  section,  as  well  as  from  other  facts.     But  this  is  a  very 
different  proposition  from  that  just  alluded-to;  and  the  difference  has  been  very 
happily  illustrated  by  Dr.  Reid.     "  The  movements  of  a  horse,"  he  observes, 
"  are  independent  of  the  rider  on  his  back,  —  in  other  words,  the  rider  does  not 
furnish  the  conditions  necessary  for  the  movements  of  the  horse;  —  but  every 
one  knows  how  much  these  movemenfs  may  be  influenced  by  the  hand  and  heel 
of  the  rider."     It  may  be  hoped,  then,  that  physiologists  will  cease  to  adduce  the 
oft-cited  experiments  of  Dr.  Wilson  Philip,  in  favour  of  the  hypothesis  (for  such 
it  must  be  termed)  that  secretion  is  dependent  upon  nervous  influence,  and  that 
this  is  identical  with  galvanism.     Additional  evidence  of  their  fallacy  is  derived 
from  the  fact  mentioned  by  Dr.  Reid,  that  the  usual  mucous  secretions  of  the 
stomach  were  always  found ;  and  they  are  further  invalidated  by  the  testimony 
of  Miiller,  who  denies  that  galvanism  has  any  peculiar  influence  in  re-establishing 
the  gastric  secretion,  when  it  has  been  checked  by  section  of  the  nerves. 

104.  Our  knowledge  of  the  nature  of  the  process  of  Gastric  Digestion  has  been 
greatly  advanced  by  recent  enquiries ;  and  we  are  now  in  a  condition  to  state  with 
considerable  precision  what  it  is,  and  what  it  is  not,  the  province  of  the  gastric 
juice  to  effect.  —  There  can  no  longer  be  any  doubt  that  the  operation  is  one 
essentially  of  chemical  solution;  and  that  the  vital  attributes  of  the  Stomach  are 
only  exercised  in  the  preparation  of  the  solvent,  and  in  the  performance  of  those 
movements  which  promote  its  action  on  the  alimentary  matters  submitted  to  it. 
The  first  series  of  facts  which  clearly  demonstrated  this  position,  were  those  that 
resulted  from  the  very  pains-taking  observations  made  by  Dr.  Beaumont,  in  the 
case  of  St.  Martin,  already  referred-to.     By  introducing  a  tube  of  india-rubber 
into  the  empty  stomach,  Dr.  B.  was  able  to  obtain  a  supply  of  gastric  juice  when- 
ever he  desired  it,  the  tube  serving  the  purpose  of  stimulating  the  follicles  to 
pour-forth  their  secretion,  and  at  the  same  time  conveying  it  away ;  and  with  the 
fluid  thus  obtained,  he  was  able  to  make  various  experiments,  which  showed  that 
the  change  which  it  effects  upon  alimentary  matter,  when  it  is  kept  at  a  tempera- 
ture of  98°  or  100°,  and  frequently  agitated,  is  not  less  complete  than  that  which 
takes  place  when  the  same  matter  is  submitted  to  its  operation  within  the  sto- 
mach, but  requires  a  longer  time.     This  is  readily  accounted-for  when  we  remem- 
ber that  no  ordinary  agitation  can   produce  the  same  effect  with  the  curious 
movements  of  the  stomach ;  and  that  the  continued  removal,  from  its  cavity,  of 
the  matter  which  has  been  already  dissolved,  must  aid  the  operation  of  the  solvent 
on  the  remainder.     The  following  is  one  out  of  many  experiments  detailed  by 
Dr.  Beaumont.      "At  11$  o'clock,  A.  M.,  after  having  kept  the  lad  fasting  for 
17  hours,  I  introduced  a  gum-elastic  tube,  and  drew  off  one  ounce  of  pure  gastric 
liquor,  unmixed  with  any  other  matter,  except  a  small  proportion  of  mucus,  into 
a  three-ounce  vial.      I  then  took  a  solid  piece  of  boiled  recently-salted  beef, 
weighing  three  drachms,  and  put  it  into  the  liquor  in  the  vial;  corked  the  vial 
tight,  and  placed  it  in  a  saucepan  filled  with  water,  raised  to  the  temperature  of 
100°,  and  kept  at  that  point  on  a  nicely-regulated  sand-bath.     In  forty  minutes, 
digestion  had  distinctly  commenced  over  the  surface  of  the  meat,     \nfifty  min- 
utes, the  fluid  had  become  quite  opaque  and  cloudy;  the  external  texture  began 


GASTRIC     DIGESTION.  117 

to  separate  and  become  loose.  In  sixty  minutes,  chyme  began  to  form.  At  1 
o'clock,  p.  M.  (digestion  having  progressed  with  the  same  regularity  as  in  the  last 
half-hour),  the  cellular  texture  seemed  to  be  entirely  destroyed,  leaving  the  mus- 
cular fibres  loose  and  unconnected,  floating  about  in  fine  small  shreds,  very  tender 
and  soft.  At  3  o'clock  the  muscular  fibres  had  diminished  one-half,  since  the  last 
examination.  At  five  o'clock,  they  were  nearly  all  digested;  a  few  fibres  only 
remaining.  At  7  o'clock,  the  muscular  texture  was  completely  broken  down,  and 
only  a  few  of  the  small  fibres  could  be  seen  floating  in  the  fluid.  At  9  o'clock 
every  part  of  the  meat  was  completely  digested.  The  gastric  juice,  when  taken 
from  the  stomach,  was  as  clear  and  transparent  as  water.  The  mixture  in  the 
vial  was  now  about  the  colour  of  whey.  After  standing  at  rest  a  few  minutes,  a 
fine  sediment  of  the  colour  of  the  meat  subsided  to  the  bottom  of  the  vial.  —  A 
piece  of  beef,  exactly  similar  to  that  placed  in  the  vial,  was  introduced  into  the 
stomach,  through  the  aperture,  at  the  same  time.  At  12  o'clock  it  was  with- 
drawn, and  found  to  be  as  little  affected  by  digestion  as  that  in  the  vial ;  there 
was  little  or  no  difference  in  their  appearance.  It  was  returned  to  the  stomach; 
and,  on  the  string  being  drawn  out  at  1  o'clock,  p.  M.,  the  meat  was  found  to  be 
all  completely  digested  and  gone.  The  effect  of  the  gastric  juice  on  the  piece  of 
meat  suspended  in  the  stomach,  was  exactly  similar  to  that  in  the  vial,  only  more 
rapid  after  the  first  half-hour,  and  sooner  completed.  Digestion  commenced  on, 
and  was  confined  to,  the  surface  entirely  in  both  situations.  Agitation  accele- 
rated the  solution  in  the  vial,  by  removing  the  coat  that  was  digested  on  the  sur- 
face, enveloping  the  remainder  of  the  meat  in  the  gastric  fluid,  and  giving  this 
fluid  access  to  the  undigested  portions."1  Many  variations  were  made  in  other 
experiments ;  some  of  which  strikingly  displayed  the  effects  of  thorough  masti- 
cation, in  aiding  both  natural  and  artificial  digestion. 

105.  The  attempt  was  made  by  Dr.  Beaumont,  to  determine  the  relative  diges- 
tibility of  different  articles  of  diet,  by  observing  the  length  of  time  requisite  for 
their  solution.2  But,  as  he  himself  points-out,  the  rapidity  of  digestion  varies  so 
greatly,  according  to  the  quantity  eaten,  the  nature  and  amount  of  the  previous 
exercise,  the  interval  since  the  preceding  meal,  the  state  of  health,  the  condition 
of  the  mind,  and  the  nature  of  the  weather,  that  a  much  more  extended  inquiry 
would  be  necessary  to  arrive  at  the  results  to  be  depended-on.  Some  important 
inferences  of  a  general  character,  however,  may  be  drawn  from  his  researches. — It 
seems  to  be  a  general  rule,  that  the  flesh  of  wild  animals  is  more  easy  of  diges- 
tion, than  that  of  the  domesticated  races  which  approach  them  most  nearly.  This 
may,  perhaps,  be  partly  attributed  to  the  small  quantity  of  fatty  matver  that  is 
mixed-up  with  the  flesh  of  the  former,  whilst  that  of  the  latter  is  largely  per- 
vaded by  it.  For  it  appears  from  Dr.  B.'s  experiments,  that  the  presence  in  the 
stomach  of  any  substance  which  is  difficult  of  digestion,  interferes  with  the  solu- 
tion of  food  that  would  otherwise  be  soon  reduced.  It  seems  that,  on  the  whole, 
Beef  is  more  speedily  reduced  than  Mutton,  and  Mutton  sooner  than  either  Veal 
or  Pork.  Fowls  are  far  from  possessing  the  digestibility  that  is  ordinarily  im- 
puted to  them ;  but  Turkey  is,  of  all  kinds  of  flesh  except  Venison,  the  most 
soluble. — Dr.  Beaumont's  experiments  further  show,  that  bulk  is  as  necessary  for 
healthy  digestion,  as  the  presence  of  the  nutrient  principle  itself.  This  fact  has 
been  long  known  by  experience  to  uncivilised  nations.  The  Kamschatdales,  for 
example,  are  in  the  habit  of  mixing  earth  or  saw-dust  with  the  train-oil,  on  which 
alone  they  are  frequently  reduced  to  live.  The  Veddahs  or  wild  hunters  of  Cey- 

1  Experiments  2  and  3  of  First  Series. 

*  It  is  important  to  bear  in  mind,  that  the  digestibility  of  different  substances  bears  no 
relation  to  their  nutrient  value,  which  is  entirely  dependent  on  their  chemical  composition. 
Of  course,  however  nutritious  a  substance  may  be,  it  is  valueless  as  an  article  of  diet  if  it 
cannot  be  dissolved ;  but,  on  the  other  hand,  substances  which  are  very  easily  digested 
(such  as  farinaceous  matters)  may  have  a  low  nutritive  value,  through  containing  but  I* 
Tery  small  proportion  of  azotized  constituents. 


118  OF    FOOD,     AND    THE    DIGESTIVE    PROCESS. 

Ion,  on  the  same  principle,  mingle  the  pounded  fibres  of  soft  and  decayed  wood 
with  the  honey  on  which  they  feed  when  meat  is  not  to  be  had  ;  and  on  one  of 
them  being;  asked  the  reason  of  the  practice,  he  replied,  "  I  cannot  tell  you,  but 
I  know  that  the  belly  must  be  filled. "  It  is  further  shown  by  Dr.  B.,  that  soups 
and  fluid  diet  are  not  more  readily  chymified  than  solid  aliment,  and  are  not  alone 
fit  for  the  support  of  the  system ;  and  this,  also,  is  conformable  to  the  well-known 
results  of  experience;  for  a  dyspeptic  patient  will  frequently  reject  chicken-broth, 
when  he  can  retain  solid  food  or  a  richer  soup.  Perhaps,  as  Dr.  A.  Combe 
remarks,  the  little  support  gained  from  fluid  diet,  is  due  to  the  rapid  absorption 
of  the  watery  part  of  it;  so  that  the  really  nutritious  portion  is  left  in  too  soft 
and  concentrated  a  state,  to  excite  the  healthy  action  of  the  stomach. — Dr.  Beau- 
mont also  ascertained,  that  moderate  exercise  facilitates  digestion,  though  severe 
and  fatiguing  exercise  retards  it.  If  even  moderate  exercise  be  taken  immediately 
after  a,  full  meal,  however,  it  is  probably  rather  injurious  than  beneficial;  but  if 
an  hour  be  permitted  to  elapse,  or  if  the  quantity  of  food  taken  have  been  small, 
it  is  of  decided  benefit.  The  influence  of  temperature  on  the  process  of  solution, 
is  remarkably  shown  in  some  of  Dr.  B.'s  experiments.  He  found  that  the  gastric 
juice  had  scarcely  any  influence  on  the  food  submitted  to  it,  when  the  bottle  was 
exposed  to  the  cold  air,  instead  of  being  kept  at  a  temperature  of  100°.  He 
observed  on  one  occasion,  that  the  injection  of  a  single  gill  of  water  at  50°  into 
the  stomach,  sufficed  to  lower  its  temperature  upwards  of  3C°;  and  that  its 
natural  heat  was  not  restored  for  more  than  half  an  hour.  Hence  the  practice 
of  eating  ice  after  dinner,  or  even  of  drinking  largely  of  cold  fluids,  is  very  pre- 
judicial to  digestion. 

106.  It  is  far  from  being  true,  however,  that  (accordiv^  to  the  older  views 
of  its  power)  the  Gastric  juice  is  capable  of  acting  upon  all  the  nutritive  compo- 
nents of  the  food.  The  mistake  probably  arose  from  the  reduction  to  which  these 
matters  are  subjected  in  digestion,  the  alimentary  bolus  being  completely  disinte- 
grated, and  its  particles  saturated  with  the  fluids  of  the  stomach,  so  that  the 
whole  forms  a  homogeneous  liquid  of  pultaceous  consistence,  to  which  the  name 
of  chyme  is  given.  This  chyme  will,  of  course,  vary  greatly  in  its  composition, 
according  to  the  proportion  of  the  different  alimentary  substances  that  have  en- 
tered into  the  composition  of  the  food;  and  its  appearance,  also,  is  far  from 
uniform,  being  sometimes  like  gruel,  but  sometimes  more  creamy,  always,  how- 
ever, having  a  strong  acid  reaction.  —  All  the  more  recent  and  accurate  experi- 
ments of  those  who  have  studied  the  chemistry  of  digestion,  lead  to  the  conclusion, 
'that  the  solvent  powers  of  the  Gastric  juice  are  entirely  limited  to  azotized  sub- 
stances; and  that  it  exerts  no  action  whatever,  upon  either  starchy,  saccharine, 
or  oleaginous  matters.  Although  the  change  in  the  starchy  particles,  which 
commences  in  the  mouth  is  usually  continued  in  the  stomach,  yet  its  continuance 
is  entirely  dependent  upon  the  presence  of  the  salivary  fluid;  being  completely 
checked  when,  by  tying  the  oesophagus,  that  fluid  is  prevented  from  passing  into 
the  stomach.1  Saccharine  matters,  being  readily  soluble  in  water,  do  not  require 
the  agency  of  the  gastric  fluid,  for  any  other  purpose  than  the  solution  of  their 
investments,  whereby  they  are  set  free;  and  it  does  not  appear  that  it  exerts  any 
converting  power  upon  them.  [According  to  the  observations  of  Dr.  Dalton, 
cane-sugar  is  slowly  converted  by  gastric  juice,  out  of  the  body,  into  glucose. 
Ten  grains  of  cane-sugar,  dissolved  in  half  an  ounce  of  gastric  juice,  and  kept  at 
100°  F.,  give  traces  of  glucose  at  the  end  of  two  hours,  and  in  three  hours  the 
quantity  is  considerable.  It  cannot  be  shown,  however,  that  the  gastric  juice 
exerts  this  effect  on  sugar  during  ordinary  digestion.  If  cane-sugar  be  given  to 
a  dog  while  digestion  of  meat  is  going  on,  it  disappears  in  from  two  to  three 
hours,  without  any  glucose  being  detected.  The  same  observer  remarks,  that  a 
curious  peculiarity  manifests  itself  in  the  action  of  cane-sugar  introduced  into  the 
itomach  while  empty.  If  half  an  ounce  of  loaf-sugar  be  given  to  the  animal 
1  See  Frerichs  in  "Wagner's  Handworterbuch,"  baud  iii.  Art.  '  Verdauung.' 


GASTRIC     DIGESTION.  119 

after  a  twelve  hours'  fast,  when  the  stomach  contains  no  food  or  gastric  juice,  it 
almost  invariably  produces  an  immediate  reflux  of  intestinal  fluids,  (among 
which  bile  is  readily  recognised  by  its  color,)  and  these  promptly  convert  a  part 
of  the  sugar  which  has  been  swallowed,  so  that  in  fifteen  to  thirty  minutes  the 
fluids  extracted  from  the  stomach  contain  an  abundance  of  glucose.  This,  how- 
ever, is  only  temporary.  In  a  space  of  time  varying  forty-five  minutes,  to  an 
hour,  the  intestinal  fluids  cease  to  be  present,  and  the  glucose  at  the  same  time 
disappears.  Unaltered  cane-sugar,  however,  still  remains,  and  continues  present 
for  twa  and  a  half  to  three  hours,  when  it  gradually  disappears,  without  any  sub- 
sequent production  of  glucose.  During  all  this  time,  no  gastric  juice  is  secreted ; 
the  reaction  of  the  stomach  remaining  constantly  neutral  or  alkaline. 

The  above  experiments  of  Dr.  Dalton  render  it  probable,  that  even  when  cane- 
sugar  is  taken  with  other  articles  of  food,  it  is  not  converted  into  glucose,  although 
of  this  there  is  no  positive  certainty;  for  it  was  found  that  Trommer's  test  failed 
to  manifest  the  presence  of  sugar  when  gastric  Juice  was  present.  Upon  which 
ingredient  of  the  gastric  juice  this  failure  depends,  is  not  known,  since  the  same 
occurrence  took  place  when  the  acid  reaction  was  neutralised,  and  the  organic 
constituent  removed. —  ED.]  So,  again,  Oleaginous  matters  are  merely  reduced 
to  a  state  of  fine  division,  and  are  diffused  in  a  state  of  suspension  through  the 
pulpy  chyme.  The  effect  of  the  gastric  fluid  upon  the  several  kinds  of  Albu- 
minous matters,  is  to  reduce  them  to  a  state  of  complete  solution,  and  at  the  same 
time  to  alter  their  chemical  properties,  so  that  they  for  the  most  part  lose  their 
distinctive  attributes,  and  are  brought  to  one  uniform  condition,  that  of  aibumi- 
nose  (a  kind  of  imperfect  albumen),  which  seems  to  be  the  state  best  adapted  for 
subsequent  assimilation.  [Albuminose  differs  from  albumen  in  not  being  coagu- 
lable  by  heat  or  by  nitric  acid,  but  is  best  precipitated  from  its  solution  by  alcohol. 
If  the  different  articles  of  food  be  digested  in  fresh  gastric  juice  in  test-tubes,  at 
a  temperature  of  100°  F.,  it  will  be  found  that  the  digestible  ingredients  of  bread 
are  all  taken  up  under  the  form  of  albuminose.  If  cheese  be  treated  in  the  same 
way,  its  casein  is  altogether  converted  into  albuminose,  and  dissolved,  while  its 
oleaginous  matters  are  set  free,  and  collect  in  a  yellow  layer  on  the  surface  of  the 
solution.  A  very  considerable  portion  of  raw  white  of  egg,  however,  dissolves  in 
the  gastric  juice  directly  as  albumen,  and  remains  coagulable  by  heat.  Soft-boiled 
white  of  egg  and  raw  meat  are  principally  converted  into  albuminose,  but  at  the 
same  time  a  small  proportion  of  albumen,  according  to  Dr.  Dalton,  is  also  taken 
up  unchanged. —  ED.']  In  this  condition,  they  seem  to  form  definite  combinations 
with  the  solvent  fluid,  which  have  received  the  name  of  peptones.  That  these 
combinations,  however,  are  very  different,  from  mere  solutions  of  the  same  matters 
in  acidulated  liquids,  has  been  shown  by  the  experiments  of  M.  Bernard;  who 
found  that,  on  injecting  the  solution  of  albumen  in  very  dilute  hydrochloric  acid 
into  the  general  circulation,  the  liquid  speedily  passed  off  by  the  renal  secretion ; 
whilst  after  injecting  the  solution  of  albumen  in  gastric  juice,  no  trace  of  this 
could  be  detected  in  the  urine.  Hence  it  seems  evident  that  a  converting  power 
is  exerted  by  the  pepsin,  or  peculiar  'ferment'  of  the  gastric  fluid,  whilst  the 
solvent  power  is  due  to  the  acid ;  a  conclusion  which  agrees  well  with  that  based 
on  other  evidence  (§  97).  It  appears  from  the  observations  of  MM.  Blondlot 
and  Bernard,  that  when  liquid  Albumen  is  taken  into  the  stomach,  it  does  not 
undergo  complete  coagulation  before  the  solvent  process  commences,  but  merely 
becomes  opalescent;  Casein,  on  the  other  hand,  is  completely  coagulated,  the 
peculiar  animal  principle  of  the  gastric  fluid  having  more  power  of  precipitating 
it,  than  is  possessed  by  any  other  re-agent.  The  gastric  fluid  has  also  a  special 
solvent  power  for  Gelatinous  substances;  acting  upon  those  which  would  have 
otherwise  required  long  boiling  for  their  disintegration.  Here,  too,  the  marked 

['  The  reader  is  referred  to  the  excellent  paper  of  Prof.  Dalton,  of  which  brief  extractg 
only  have  been  given,  for  a  more  detailed  account  of  gastric  digestion.  Amer.  Jour. 
Med.  Sci.,  Oct.  1854.] 


120      OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 

difference  in  action  between  the  gastric  juice  and  a  merely  acidulous  fluid  has 
been  demonstrated  by  M.  Bernard;  who  has  shown  that,  when  a  piece  of  bone 
is  submitted  to  the  latter,  its  mineral  portion  alone  is  affected  by  it;  whereas 
when  it  is  subjected  to  the  former,  the  gastric  juice  digests  the  gelatin,  and 
leaves  the  phosphates  and  carbonates  unaltered.  Moreover,  a  decided  transforma- 
tion is  effected  by  the  operation  of  the  gastric  fluid;  for  the  gelatin  of  the  pep- 
tone has  lost  its  power  of  gelatinizing,  and  is  not  precipitated  by  chlorine. 

107.  This  action  of  the  Gastric  solvent  upon  the  azotized  constituents  of  the 
food,  is  dependent  upon  several  accessory  conditions.    One  of  the  most  important 
of  these  is  temperature.     A  heat  of  from  96°  to  100°  is  required  to  keep-up  the 
solvent  process,  which  is  retarded  according  to  the  depression  of  the  thermometer 
below  this  standard;  so  that  at  the  ordinary  temperature  of  the  atmosphere  it  is 
completely  suspended,  to  be  renewed,  however,  with  an  increment  of  heat.     On 
the  other  hand,  a  trifling  elevation  of  temperature  above  100°  occasions  a  decom- 
position in  the  gastric  juice,  which  entirely  destroys  its  solvent  power.  —  The 
next  condition,  which  specially  affects  the  time  required  for  the  process  of  solu- 
tion, is  motion.     This  does  not  act  mechanically,  by  way  of  *  trituration/  as  was 
once  supposed;  for  food  is  found  to  be  digested,  when  enclosed  in  metallic  balls 
perforated  to  admit  the  access  of  gastric  juice  to  their  interior.     But  it  answers 
the  purpose  of  thoroughly  subjecting  the  whole  of  the  alimentary  bolus  to  the 
agency  of  the  gastric  solvent,  by  bringing  each  part  successively  into  contact  with 
the  lining  membrane  of  the  stomach  from  the  surface  of  which  the  fluid  is  effused. 
The  removal  of  the  matters  already  reduced  or  dissolved,  also,  has  a  most  im- 
portant effect  in  facilitating  the  solution  of  the  remainder.     This  removal  is  due 
in  part  to  the  absorption  of  the  matters  in  a  state  of  solution,  into  the  blood- 
vessels of  the  walls  of  the  stomach  (§  122);  and  in  part  to  the  successive  escape 
of  the  reduced  portions  through  the  pyloric  orifice  (§  83).     The  importance  of  the 
previous  state  of  minute  division  and  incorporation  with  aqueous  fluid,  in  pro- 
moting the  action  of  the  gastric  solvent,  has  been  already  dwelt-on  (§  78). 

108.  Although  the    Chyme,  or  product  of   gastric  digestion,  which  escapes 
through  the  pyloric  orifice  into  the  duodenum,  contains  much  azotized  matter  in 
a  state  of  actual  solution,  a  considerable  proportion  of  it  is  still  only  reduced  and 
mechanically  suspended;  and  the  solution  of  the  latter  is  continued  in  the  intes- 
tinal tube.     In  the  farinaceous  part  of  the  food,  moreover,  no  great  amount  of 
change  has  hitherto  been  effected ;  and  the  sugar  which  has  been  generated  by 
the  agency  of  the  salivary  ferment,  is  probably  absorbed  in  the  blood-vessels 
nearly  as  fast  as  it  is  formed.     In  the  condition  of  the  fatty  matters,  no  important 
change  is  perceptible,  except  such  as  results  from  the  solution  of  the  membranes, 
&c.,  that  enclosed  them.     Hence  we  see  that  the  process  of  Digestion,  so  far 
from  being  completed  in  the  stomach,  has  only  been  carried  one  stage  further. 
Soon  after  its  entrance  into  the  Duodenum,  the  chyme  is  subjected  to  the  actions 
of  the  Bile,  the  Pancreatic  fluid,  and  that  secretion  from  the  glandulse  in  the 
walls  of   the  intestine  itself  (proceeding  chiefly,   perhaps,  from    the  glands  of 
Brunner,  §  113),  which  is  known  under  the  name  of  '  Succus  Entericus.' — Of 
these,  the  Pancreatic  fluid  will  be  first  noticed.     The  structure  of  the  Pancreas 
closely  resembles  that  of  the  Salivary  glands  (§  90) ;  for  it  consists  of  racemose 
clusters  of  secreting  follicles,  which  form  the  terminations  of  the  ramifying  divi- 
sions of  the  duct;  each  cluster,  with  its  blood-vessels,  lymphatics,  nerves,  and 
connecting  tissue,  forming  a  lobule ;  and  the  separate  lobules  being  held-together 
by  areolar  tissue,  as  well  as  by  the  vessels  and  ducts.      Like  the  salivary  glands, 
moreover,  its  development  commences  by  a  sort  of  budding-forth  of  the  alimen- 
tary canal  at  a  particular  spot,  upon  which  a  mass  of  cells  has  previously  accu- 
mulated.    The  secretion  of  this  gland  strongly  resembles  saliva  in  its  general 
appearance,  being  clear  and  colourless,  slightly  viscid,  and  alkaline  in  its  reaction; 
it  contains,  however,  a  larger  proportion  of  solid  matter,  its  specific  gravity  being 
10U8   or  1009;    and   the   nature  of  its  animal  principle  is  not  precisely  the 


PANCREATIC    FLUID.  121 

same.     The  following  is  Professor  Frerichs'  analysis  of  the  pancreatic  fluid  of 

the  Ass. 

Water 986-40 

Solids 13-60 


Fat 0-26 

Alcohol-extract 0-15 

Water-extract,  albuminous 3-09 

(Chlorides     ^ 

Phosphates  L  8-90 
Sulphates    J 

Carbonate  and  phosphate  of  lime  and  magnesia 1-20 


1000-00       13-60 

It  is  remarkable,  however,  that  in  the  Dog,  the  solid  residue  (according  to 
Schmidt)  should  be  nearly  10  per  cent,  or  even  more;  and  that  this  should  be 
almost  entirely  composed  of  organic  matter,  the  inorganic  constituents  being  in 
no  larger  amount  than  in  the  pancreatic  fluid  of  the  ass.  The  difference  in  the 
nature  of  the  alimentary  materials  on  which  the  pancreatic  fluids  of  these  two 
animals  are  destined  to  act,  is  probably  the  explanation  of  this  marked  variation 
in  their  composition. —  The  albuminous  'ferment'  is  n-ot  perfectly  coagulable  by 
heat,  and  when  precipitated  by  alcohol  it  redissolves  readily  in  water;  it  is  pre- 
cipitated by  sulphuric,  nitric,  and  concentrated  hydrochloric  acid,  and  by  the 
metallic  salts;  and  when  thrown-down  by  these,  or  by  heat,  it  is  redissolved  by 
alkalies.  It  is  also  precipitated  by  acetic  acid ;  but  it  slowly  redissolves  in  an 
excess  of  the  reagent,  and  on  the  application  of  heat;  and  from  this  solution  it 
is  precipitated  by  ferrocyanide  of  potassium.  When  boiled  with  ammonia,  it 
assumes  an  intense  yellow  colour.  The  readiness  with  which  this  substance  un- 
dergoes change,  is  indicated  by  the  rapidity  with  which  the  pancreatic  fluid  passes 
into  decomposition ;  for  even  after  a  few  hours'  exposure  to  the  air,  it  gives-off  a 
decidedly  putrid  odour.  Like  ptyalin,  though  in  a  less  degree,  this  peculiar  con- 
stituent of  the  pancreatic  fluid  possesses  the  power  of  converting  starch  into 
sugar ;  there  can  be  no  doubt,  therefore,  that  it  is  subservient  to  the  continued 
digestion  of  the  farinaceous  part  of  the  food,  during  its  passage  through  the  small 
intestines.  It  shares  this  office,  however,  with  the  '  succus  entericus/  which  has 
been  shown  by  Frerichs  and  Htibbenet  to  be  also  possessed  of  this  converting 
power. 

109.  It  has  recently  been  affirmed  by  M.  Cl.  Bernard,  and  strong  evidence  has 
been  adduced  by  him  in  support  of  his  statement,  that  the  essential  purpose  of  the 
Pancreatic  fluid  is  to  promote  the  absorption  of  fatty  matters,  by  reducing  them 
to  the  state  of  an  emulsion,  which  is  capable  of  finding  its  way  into  the  lac-teals.1 
That  this  fluid  possesses  the  emulsifying  power  in  a  peculiar  degree,  may  be  con- 
sidered as  having  been  fully  demonstrated  by  his  experiments ;  for  on  mixing  it 
with  oil,  butter,  or  any  variety  of  fat,  at  a  temperature  sufficiently  high  to  render 
the  fatty  substance  liquid,  and  then  stirring  the  mixture  for  a  few  minutes,  an 
emulsion  is  produced  bearing  a  strong  resemblance  to  chyle.  This  emulsion  does 
riot  cease  to  present  its  peculiar  aspect,  although  left  standing  for  some  time; 

1  "  Archiv.  Ge'ne'r.  de  Me*d.,"  torn.  xix.  —  It  has  been  assumed  by  Frerichs,  Lenz,  and 
other  objectors  to  M.  Bernard's  views,  that  he  maintains  that  the  pancreatic  fluid  saponifies 
the  neutral  fatty  matters  taken-in  as  food,  converting  them  into  fatty  acids  and  glycerine 
whilst  yet  within  the  intestinal  canal.  It  is  no  doubt  true  that  M.  Bernard  considers  that 
some  such  transformation  takes  place  in  the  body,  before  the  fatty  matter  is  ultimately 
disposed  of;  but  he  constantly  speaks  of  the  emulsifying  power  as  the  peculiar  attribute 
of  the  pancreatic  fluid,  and  only  asserts  that  saponification  takes  place  in  artificial  diges- 
tion, when  the  fluid  is  left  for  some  time  in  contact  with  fatty  substances ;  so  that  the 
Author  is  inclined  to  regard  the  objections  above  alluded-to,  as  having  arisen  from  a  mis- 
apprehension of  M.  Bernard's  meaning.  (See  also  Dr.  Donaldson's  account  of  M.  Bernard's 
discoveries,  in  the  "Amer.  Journ.  of  Med.  Sci.,"  Oct.  1851. 


122      OF  FOOD,  AND  THE  DIGESTIVE  PROCESS. 

whereas  although  bile,  saliva,  gastric  juice,  blood-serum,  and  other  animal  fluids, 
have  a  certain  emulsifying  power,  yet  after  a  short  time  the  oil-particles  run 
together  again,  almost  ns  if  they  had  been  merely  shaken-up  with  water.  Fur- 
ther, it  is  asserted  by  Bernard,  that  in  the  Rabbit  (in  which  the  pancreatic  duct 
discharges  itself  some  inches  lower  down  in  the  intestine  than  does  the  bile-duct), 
when  fatty  matters  have  been  introduced  into  the  alimentary  canal,  they  undergo 
no  considerable  change,  until  they  have  passed  the  orifice  of  the  pancreatic  duct ; 
an  oily  emulsion  being  then  for  the  first  time  found  in  the  intestinal  canal,  and 
the  opaque  whiteness  of  chyle  showing  itself  in  the  contents  of  those  absorb- 
ents only,  which  originate  in  the  intestinal  villi  below  that  orifice.  So,  again, 
M.  Bernard  affirms  that  by  putting  a  ligature  round  the  pancreatic  duct,  the 
digestion  of  oleaginous  matter  is  so  completely  prevented,  that  it  is  found  un- 
changed in  the  lower  part  of  the  intestinal  tube,  and  no  opalescent  chyle  is  found 
in  the  lactcals.  This  position  is  further  strengthened  by  the  fact  ascertained  by 
clinical  observation,1  that  there  is  a  close  relation  between  disease  of  the  pan- 
creas, and  the  discharge  of  fatty  matters  per  anum. — It  has  been  shown,  however, 
by  the  experimental  researches  of  Frerichs,  Lehmann,  Lenz,2  and  others,  that  the 
statements  of  M.  Bernard  are  too  exclusive  in  their  character;  for  that  the  di- 
gestion and  absorption  of  fatty  matters  will  take  place  after  the  pancreatic  duct 
has  been  tied  (sufficient  time  having  been  given  for  the  evacuation  of  any  pancre- 
atic fluid  which  may  have  been  in  the  alimentary  canal  previously  to  the  opera- 
tion), and  even  in  the  lower  part  of  the  small  intestine,  into  which  these  substances 
have  been  conveyed  by  injection,  after  it  has  been  completely  separated  by  a 
ligature  from  the  upper  part  into  which  the  pancreatic  fluid  has  been  poured.  It 
further  appears  from  their  experiments,  that  a  mixture  of  the  pancreatic  fluid 
with  bile  and  the  l  succus  entericus/  possesses  a  more  energetic  emulsifying 
power  than  the  first  of  these  fluids  alone;  and  it  seems  probable  that,  as  in  the 
conversion  of  starch,  so  in  the  emulsification  of  fat,  the  intestinal  fluid  performs 
a  very  important  part.  It  would  not  seem  unlikely  that  the  qualities  of  these 
fluids  (like  those  of  the  saliva)  may  vary  in  different  animals ;  and  that  the  emul- 
sifying power  may  be  limited  in  the  rabbit,  or  nearly  so,  to  the  pancreatic  fluid, 
the  quantity  of  fat  which  its  natural  food  contains  being  small ;  whilst  in  the 
carnivorous  animals,  whose  natural  food  is  more  oleaginous,  the  provision  for  the 
digestion  of  fatty  matters  may  be  more  extensive.  [The  experiments  of  M.  Ber- 
nard have  been  repeated  by  Prof.  Jackson,  of  the  University  of  Pennsylvania,3 
and  by  the  editor  before  the  class  of  the  Medical  Department  of  Pennsylvania 
College,  with  precisely  the  same  results  as  those  detailed  by  M.  B. 

The  objections  of  Bidder,  Lehraann,  Schmidt,  and  Frerichs  are  regarded  by 
Dr.  Jackson  as  wholly  inconclusive.  These  observers,  after  tying  the  pancreatic 
duct  as  above  stated,  and  the  small  intestines  below  the  duct  in  another  instance, 
injected  milk,  or  milk  with  olive  oil,  into  the  intestines,  and  found  the  lacteuls 
filled  with  white  chyle.  This  was  to  be  expected,  for  the  necessary  condition  for 
the  absorption  of  fatty  matters  by  the  lacteals  is,  that  they  exist  as  an  emulsion. 
Milk,  as  Dr.  Jackson  states,  is  a  natural  emulsion,  holding  a  fatty  substance 
(cream)  in  suspension,  and  consequently  in  the  condition  for  absorption.  Milk 
forms  an  emulsion  with  oils,  and  creates  the  same  condition.  Still  more  extraor- 
dinary is  the  experiment  of  Frerichs,  quoted  against  M.  Bernard  by  Lehmann, 
in  which  he  injected  an  emulsion  of  oil  and  albumen  into  the  ligated  intestine, 
and  its  absorption  was  considered  as  a  refutation  of  M.  01.  Bernard's  doctrine. 

1  See  Dr.  Bright's  researches  on  this  point,  in  "  Med.-Chir.  Trans.,"  vol.  xviii.  ;   also  an 
Article  on  Pancreatic  Disease  and  Fatty  Discharges,  in  "Brit,  and  For.  Med.-Chir.  Rev.," 
vol.  xii.  p.  154.      [A  case  is  reported  by  Prof.  Jackson,  of  Philadelphia,  in  which  large 
quantities  of  yellow  fatty  matter  were  found  in  the  colon  of  a  man  who  died  of  scirrhus 
of  the  pancreas,  and  whose  principal  nutriment  had  consisted  of  cream,  a  large  proportion 
of  the  fatty  bodies  of  which  had  undergone  no  emulsive  action,  and  had  not  been  ab- 
sorbed.—  ED.] 

2  "  De  Adipis  Concoctione  et  Ahsorptione,"  Dorpat,  1850. 
*  Amer.  Jour.  Med.  Sci.,  Oct.  1854. 


PROPERTIES     OF    PANCREATIC    FLUID.  128 

The  albumen  of  egg  forms  a  most  perfect  and  a  persistent  emulsion  with  oils. 
The  pure  pancreatic  juice  does  the  same.  This  Dr.  Jackson  has  witnessed,  and 
states  that  the  oil  does  not  "  soon  separate  again  on  the  surface,"  as  Lelimann 
asserts.  The  pancreatic  juice,  as  Lehmann  shows,  differs  very  slightly  from  pure 
albumen.  No  other  intestinal  fluid  possesses  this  character  so  strongly,  and  no 
other  is  as  well  adapted  to  emulsify  the  fats  of  our  aliment. 

The  cystic  bile  is  viscid  from  containing  a  larger  amount  of  mucus  derived 
from  its  mucous  membrane,  and  by  agitation  forms  an  emulsion  with  oils.  This 
emulsion,  he  states,  has  always  appeared  very  inferior  to  that  obtained  from  pure 
pnncreatic  juice,  or  albumen  of  egg.  Neither  is  it  as  persistent,  the  oil  beginning 
in  a  few  hours  to  separate.  The  hepatic  bile  is  much  thinner  and  contains  much 
less  mucus.  It  is  unknown  whether  it  will  form  an  emulsion  with  fats ;  it  may 
be  considered  as  very  doubtful.  No  positive  facts  are  known  as  to  the  quantity  of 
cystic  bile  that  enters  into  the  duodenum  during  digestion.  The  probability  is, 
that  it  is  very  small,  in  comparison  to  the  amonnt  of  freshly-secreted  hepatic  bile 
coming  directly  from  the  liver.  This  view  gives  additional  confirmation  to  M. 
Bernard's  doctrine. 

The  liquid  albuminose  .resulting  from  the  digestion  of  the  albuminous  principle 
of  the  food,  which  is  found  often  in  the  intestinal  canal  during  digestion,  may, 
from  its  accidental  presence,  concur  occasionally  in  the  formation  of  the  emulsion 
of  oils.  The  pancreatic  juice  is,  in  the  present  state  of  our  knowledge  of  the 
facts,  the  only  intestinal  humour  that  can  exercise  this  office  as  a  permanent 
function. 

In  regard  to  the  conclusion  of  M.  Bernard,  that  the  fats  were  decomposed  by 
the  pancreatic  juice,  as  assumed  by  Frerichs  and  Lenz,  even  if  so  asserted,  it  is 
not  probable,  for,  as  stated  by  Dr.  Jackson,  the  emulsion  of  fats  is  a  physical,  not 
a  chemical  process.  It  consists  of  the  mechanical  division  of  fats  into  the  mi- 
nutest globules,  each  coated  with  a  delicate  film  of  the  emulsifying  body — albumen 
in  chyle  —  casein  in  cream.  If  the  experiment  of  Bouchardat  and  Sandras  be 
correctly  reported,  it  is  conclusive  on  this  point.  They  gave  to  a  dog  a  consider- 
able quantity  of  sweet  almond-oil.  After  some  hours  the  animal  was  killed. 
Some  of  the  oil,  unchanged,  was  found  in  the  stomach  and  intestines.  The  lac- 
teals  were  filled  with  white  chyle,  as  also  the  thoracic  duct.  A  portion  obtained 
from  this  last  was  treated  with  sulphuric  ether,  and  the  almond-oil  was  obtained 
unchanged  in  its  properties. 

"  The  principal  fact  relied  on  by  the  above  German  physiologists  to  controvert 
M.  Bernard's  theory  of  fatty  decomposition  by  the  pancreatic  juice,  is  of  no  value. 
Butter  was  given  to  cats  and  dogs,  and  butyric  acid  was  sought  for,  but  not  found  in 
the  intestines.  This  is  considered  as  proof  that  the  butter  was  not  decomposed. 
It  proves  nothing  of  the  kind.  Butyric  acid  readily  decomposes.  It  cannot 
resist  the  activity  of  the  numerous  chemical  reactions  at  work  in  the  alimentary 
canal  during  digestion.  Lactic  acid  is  being  formed  incessantly  in  the  lungs  and 
intestines  from  the  metamorphosis  of  glucose,  sugar,  and  starch ;  it  is  as  speedily 
decomposed.  The  same  occurs  with  the  bile.  In  the  faecal  matters,  in  a  normal 
state  of  the  bowels,  very  little  of  the  biliary  constituents,  other  than  the  colour- 
ing matter,  is  to  be  found.  The  conjugate  biliary  acids  —  glyco-cholic  and  tauro- 
cholic  —  disappear  and  are  destroyed.  Glycocol  is  not  found;  taurin,  occasionally 
detected  in  the  middle  of  the  alimentary  tract,  disappears  at  the  lower  portion. 
The  albuminous  materials  of  the  food  that  pass  beyond  the  stomach,  are  metamor- 
phosed in  the  intestines.  In  this  conflict  of  molecular  and  chemical  reactions,  it 
would  be  impossible  for  butyric  acid  to  exist.  Its  absence  is  no  evidence  that  it 
was  not  eliminated. 

The  strongest  objection  to  M.  Bernard's  docrine  is,  that  in  an  emulsion  of  oil 
formed  with  pure  albumen  the  fatty  body  is  not  decomposed.  An  emulsion  is  a 
physical,  not  a  chemical  process. 

It  consists  in  the  reduction  of  oil  to  the  minutest  particles  —  globulets  —  each 
covered  with  a  coat  of  albumen  when  it  is  the  emulsifying  body.  This  is  ull  that 


124  OF    FOOD,     AND    THE    DIGESTIVE    PROCESS. 

is  required  to  impart  to  fats  the  capacity  for  absorption  into,  and  their  passage 
through  tissues. 

The  adoption  of  M.  Bernard's  doctrine  involves  an  inexplicable  difficulty.  If 
the  neutral  fats  are  decomposed  by  the  pancreatic  juice  before,  or  at  the  time 
of  absorption,  as  they  are  found  to  exist  in  the  adipose  tissue  in  their  original 
state  of  neutral  fats,  they  must  be  recomposed  again  in  the  blood,  or  at  the  instant 
of  their  secretion.  To  accomplish  this  change  there  must  be  a  generation  of  oxide 
of  lipyl  and  glycerin,  the  bases  of  neutral  fats.  It  is  difficult  to  understand  how 
it  can  occur.  It  is  true,  Mulder  has  offered  a  very  ingenious  hypothesis  to  show 
the  possibility  of  the  formation  of  those  bodies,  in  the  economy,  from  lactic  acid. 
But  the  whole  matter  is  so  entirely  hypothetical,  in  its  present  state,  that  it  does 
not  comport  with  the  more  rigid  canons  of  modern  medical  philosophy,  and  can- 
not be  accepted. 

The  state  of  our  knowledge  may  be  summed  up  in  the  following  conclusions :  — 

a.  Liquid  fats  are  not  miscible  with  the  aqueous  albumino-saline  fluid  —  liquor 
sanguinis — with  which  all  the  vascular  tissues  are  saturated;  it  cannot  enter  their 
pores,  and  consequently  cannot  be  absorbed. 

6.  Liquid  fats,  when  emulsified  by  albumen,  are  reduced  to  minute  particles, 
each  coated  with  albumen.  In  this  state  they  are  miscible  with  the  liquor  san- 
guinis moistening  the  tissues,  can  enter  their  pores,  and  are  then  capable  of 
absorption.  This  is  the  sole  condition  requisite  for  the  absorption  of  fats. 

c.  The  white  milk-like  fluid,  named  chyle,  is  this  emulsion  of  the  fatty  matters 
of  the  food  mixed  with  the  ordinary  lymph  always  contained  in  the  lymphatics 
of  the  alimentary  canal,  and  other  abdominal  organs  and  mesentery.     The  mo- 
lecular base  of  Gully  is  the  microscopic  appearance  in  the  chyle  of  the  minute 
globulets  of  fat  coated  with  albumen. 

d.  Albumen  forms  a  perfect  and  persistent  emulsion  with  oils.     The  pancreatic 
fluid  is  a  saturated  albuminous  solution,  and  forms  with  oils  an  emulsion  equally 
as  perfect  and  permanent  as  that  of  albumen. 

e.  The  pancreatic  juice  is  the  only  highly  albuminous  fluid  in  the  alimentary 
canal,  that  can  accomplish  the  formation  of  a  perfect  emulsion;  and  the  opinion 
of  M.  01.  Bernard,  that  this  process  is  one  of  its  functions,  is  sustained. 

/.  The  observations  of  M.  Cl.  Bernard,  that  the  formation  of  the  emulsion  of 
fats  in  rabbits  is  at  and  below  the  pancreatic  duct,  and  not  above  it,  is  confirmed 
by  the  experiments  detailed  above.  And,  further,  that  the  experiments  on  rab- 
bits are  the  most  reliable,  as  being  a  true  exemplification  of  the  natural  .process, 
unattended  with  violence  and  torture  to  the  animals,  more  or  less  disturbing  in 
their  effects. 

g.  That  M.  Cl.  Bernard's  view  of  the  decomposition  of  fats  by  the  pancreatic 
juice  is  not  proved,  is  opposed  by  the  nature  of  the  process,  and  by  analogy  with 
other  emulsions:  it  is  unnecessary  to  the  accomplishment  of  the  absorption  of 
fats,  and  introduces  other  and  complicated  processes  that  are  unknown  to  exist, 
and  are  mere  hypotheses."  '  ED.]  —  Of  the  amount  of  pancreatic  fluid  which  is 
daily  secreted  by  Man,  we  have  no  satisfactory  data  for  forming  an  estimate;  ac- 
cording to  the  experiments  and  calculations  of  Bidder  and  Schmidt  (op.  cit.),  it 
is  about  7  oz. 

110.  The  Duodenum  receives  not  only  the  Pancreatic,  but  also  the  Biliary 
secretion  ;  and  from  the  constancy  with  which  this  fluid  is  poured  into  the  upper 
part  of  the  intestinal  tube,  or  even  into  the  stomach  itself,  in  all  animals  which 
have  any  kind  of  hepatic  apparatus,2  it  seems  a  legitimate  inference  that  this 

1  [See  Amer.  Jour.  Med.  Sci.,  Oct.  1854,  in  which  the  whole  of  Dr.  Jackson's  valuable 
paper  appears.] 

a  See  "Princ.  of  Comp.  Phys.,"  Am.  Ed.,  1854,  §|  405-411.— The  simplest  condition  of 
the  Liver,  such  as  we  meet  with  in  the  higher  lladiata,  and  in  the  lower  Articulata  and 
Mollusca,  consists  in  a  series  of  follicles  lodged  in  the  walls  of  the  stomach  and  of  the 
upper  part  of  the  intestinal  tube. 


PROPERTIES    OF    PANCREATIC    FLUID    AND    BILE.  125 

secretion  is  not  purely  excrementitious,  but  serves  some  important  purpose  in  the 
digestive  process.  It  is  not  easy,  however,  to  state  with  precision  what  this  pur- 
pose is.  The  results  of  many  of  the  experiments  which  have  be-en  made  to 
determine  it,  are  vitiated  by  the  fact,  that  the  pancreatic  duct  in  most  cases  dis- 
charges itself  into  the  intestinal  tube  at  the  same  point  with  the  hepatic,  and  has 
thus  been  frequently  involved  in  operations  performed  upon  it.  —  As  the  most 
important  constituents  of  Bile,  and  the  agency  of  the  Liver  as  an  assimilating 
and  depurating  organ,  will  be  more  appropriately  considered  elsewhere  (CHAPS. 
IV.  and  IX.),  we  shall  here  limit  ourselves  to  the  consideration  of  what  may  be 
regarded  as  the  best-established  facts  in  regard  to  the  uses  of  the  biliary  secretion 
in  the  digestive  process. 

111.  When  its  action  is  tested  out  of  the  body,  by  mingling  it  with  the 
different  constituents  of  food,  it  is  found  to  exert  no  change  upon  starchy 
substances  whilst  it  is  fresh ;  though,  when  in  a  state  of  incipient  decomposi- 
tion, it  acts  upon  them  as  other  animal  substances  do.  It  has  110  action  upon 
cane-sugar,  until  it  has  stood  a  considerable  length  of  time;  but  then  it  converts 
it  into  lactic  acid.  This  change  it  speedily  exerts,  as  do  nearly  all  other  animal 
substances,  upon  grape-sugar.  It  has  no  action  on  albuminous  substances,  even 
when  acidulated.  And  although  it  will  form  an  emulsion  with  oleaginous  matter, 
yet  the  emulsification  is  less  complete  than  that  which  is  effected  by  the  pancre- 
atic fluid  alone.1  Hence  it  appears  to  be  deficient  in  anything  at  all  similar  to 
the  peculiar  ferments  of  the  saliva,  gastric  juice,  and  pancreatic  secretion ;  and 
its  office  in  digestion  must  be  of  a  different  character  from  that  of  either  of  those 
fluids.  The  nature  of  this  office  may  be  partly  judged-of,  from  what  takes  place 
when  fresh  bile  is  mingled  with  the  product  of  gastric  digestion.  The  acid  re- 
action of  the  latter  is  neutralized  by  the  alkali  of  the  former,  and  a  sort  of  preci- 
pitation takes  place  (as  was  originally  noticed  by  Dr.  Beaumont),  in  which  certain 
constituents  of  the  bile  fall  down,  and  in  which  also  (according  to  M.  Bernard) 
the  albuminous  matters  that  have  been  dissolved,  although  not  yet  absorbed,  are 
for  a  time  rendered  insoluble,  leaving  the  saccharine  matters  in  solution,  and  the 
oleaginous  floating  on  the  top.  The  admixture  of  the  bile  with  the  chyme  seems 
further  to  have  the  effect  of  checking  destructive  chemical  changes  in  its  compo- 
sition. For  M.  Bernard  found  that  when  two  similar  pieces  of  meat  had  been 
immersed  for  three  months,  one  in  a  bottle  of  gastric  juice  alone,  and  the  other 
in  a  mixture  of  gastric  juice  and  bile,  a  strong  ammoniacal  odour  resulting  from 
decomposition  was  emitted  from  the  former,  whilst  the  latter  was  pure  and  free 
from  any  smell  whatever.  And  it  was  remarked  by  MM.  Tiedemann  and  Gmelin 
(and  also  recently  by  Hoffmann),  that  when  the  bile  was  prevented  from  passing 
into  the  alimentary  canal,  the  contents  of  the  latter  were  more  foetid  than  usual. 
Moreover,  it  is  found  that  the  admixture  of  bile  with  fermenting  substances 
checks  the  process  of  fermentation ;  and  M.  Bernard  has  shown  by  ingeniously- 
contrived  experiments,2  that  this  antagonistic  power  is  exerted  also  in  the  living 
body.  Hence  we  can  understand  how  the  reflux  of  bile  into  the  stomach  should 
seriously  interfere  with  the  process  of  gastric  digestion ;  and  how,  when  there  is 
a  deficient  secretion  of  bile,  or  more  food  is  swallowed  than  the  bile  provided  for 
it  can  act-upon,  or  the  character  of  the  biliary  secretion  itself  has  undergone  any 
serious  perversion,  there  should  be  much  more  than  the  normal  amount  of  putre- 
factive fermentation,  as  is  indicated  by  an  evolution  of  flatus,  and  very  frequently 
by  diarrhoea.  Further,  the  want  of  proper  neutralization  of  the  gastric  fluid  will 
cause  the  continuance  of  acidity  in  the  contents  of  the  intestinal  canal,  which  in 
its  turn  induces  a  state  of  irritation  of  its  mucous  membrane,  and  a  perversion 
of  its  secretions :  and  it  is  one  of  the  beneficial  results  of  l  alterative '  medicines, 
employed  to  remedy  this  condition,  that,  by  augmenting  the  secretion  of  bile,  they 
tend  to  reproduce  a  state  of  neutrality  in  the  contents  of  the  alimentary  canal. 
Moreover,  the  presence  of  a  proper  quantity  of  bile  in  the  intestine  seems  to 

1  Dr.  Bence  Jones,  in  the  "  Medical  Times,"  July  5,  1851. 
8  "Amer.  Journ.  of  Med.  Sci.,"  Oct.  1851,  p.  351. 


126  OF     FOOD,    AND     THE    DIGESTIVE     PROCESS. 

promote  the  secreting  action  of  the  intestinal  glandulse,  and  also  to  contribute  to 
maintain  the  peristaltic  movement  of  the  walls  of  the  canal ;  this  appears  alike 
from  the  tendency  to  constipation,  which  is  usually  consequent  upon  deficiency 
of  the  secretion,  and  from  the  diarrhoea  which  proceeds  from  its  excess;  and  is 
confirmed  by  the  purgative  properties  which  inspissated  ox-gall  has  been  found  to 
possess. 

112.  Notwithstanding  all  its  uses,  however,  it  must  be  admitted  that  the  pre- 
vention of  the  discharge  of  bile  into  the  alimentary  canal  is  not  attended  with 
the  deleterious  results  which  might  have  been  anticipated  from  it;  for  it  has  been 
found  by  the  experiments  of  Schwann,  Blondlot,  and  Bernard,  that  if  the  bile- 
duct  be  divided,  and  a  tube  be  inserted  in  it  in  such  a  manner  as  to  convey-away 
the  secretion  through  a  fistulous  orifice  in  the  abdominal  parietes,  the  animals 
thus  treated  may  live  for  weeks,  months,  or  even  years,1  although  they  usually 
die  at  last  with  signs  of  inanition.  Of  the  quantity  of  bile  daily  poured  into  the 
alimentary  canal  of  Man,  we  have  no  other  mode  of  forming  an  estimate,  than 
by  observing  the  quantity  poured-out  from  the  bile-ducts  of  animals  in  such 
experiments  as  those  just  cited.  Blondlot  found  that  a  dog  in  which  he  had 
established  a  fistulous  opening  for  the  discharge  of  the  bile,  secreted  from  40  to 
50  grammes  in  the  twenty-four  hours ;  whence  he  inferred  that  an  adult  Man 
secretes  about  200  grammes,  or  7  oz.  On  the  other  hand,  it  is  estimated  by 
Bidder  and  Schmidt,  from  the  results  of  their  experiments  on  various  animals, 
that  the  daily  amount  of  bile  secreted  by  Man  is  not  less  than  56  oz.  (avord.); 
of  which  about  5  per  cent  is  solid  matter.  It  appears  from  the  carefully-con- 
ducted observations  of  these  laborious  investigators,2  that  the  rate  of  secretion  is 
by  no  means  uniform,  but  that  it  bears  a  certain  relation  to  the  digestive  process; 
the  quantity  poured-forth  in  a  given  time  being  greatest  about  10  or  12  hours 
after  a  full  meal,  and  then  diminishing  until  it  reaches  its  minimum,  for  which 
about  as  many  more  hours  are  required.  Thus  a  Cat,  2  hours  after  a  full  meal  of 
flesh,  secreted  at  the  rate  of  7'5  grains  of  bile  per  hour;  at  the  4th  hour,  9*7 
grains;  at  the  6th  hour,  11'6  grains;  at  the  8th  hour,  12'7  grains;  and  at  the 
lOtli  hour,  13  grains.  From  the  10th  to  the  24th  hour,  the  secretion  diminished 
at  the  rate  of  4-10ths  of  a  grain  per  hour;  until  it  reached  the  lowest  of  the 
above  amounts.  The  secretion  diminishes  considerably  when  food  is  withheld  for 
some  time ;  the  quantity  poured-out  after  ten  days'  starvation  being  only  about 
one-eighth  of  what  it  is  when  at  its  maximum.  Still  it  is  obvious,  that  although 
its  rate  is  thus  greatly  influenced  by  the  stage  of  the  digestive  process  (which  is 
the  less  to  be  wondered-at,  when  it  is  remembered  that  the  secretion  is  formed  from 
blood  that  is  charged  with  newly-absorbed  and  imperfectly-assimilated  matters),  the 
excrementitious  character  of  the  secretion  requires  that  its  elimination  shall  be 
constantly  going-on  to  a  certain  degree ;  but  a  receptacle  is  provided  in  Man,  as 
in  most  others  among  the  higher  animals  whose  digestion  is  performed  at  inter- 
vals, for  the  storing-up  of  the  fluid  until  it  can  be  usefully  employed  in  that 
process.  The  intestinal  orifice  of  the  ductus  choledochus  is  closed  by  a  sort  of 
sphincter;  and  the  fluid  secreted  during  the  intervals  of  digestion,  not  being  pro- 
pelled with  a  force  sufficient  to  dilate  this,  flows  back  into  the  gall-bladder,  which 
dilutes  to  receive  it.  The  presence  of  food  in  the  duodenum  seems  to  excite  the 
walls  of  the  gall-bladder  and  of  the  biliary  ducts  (which  contain  a  large  quantity 
of  non-striated  muscular  fibre),  to  a  contraction  sufficiently  powerful  to  propel 
their  contents  into  the  intestine,  in  spite  of  the  opposition  of  the  sphincter;  but 
whether  this  takes  place  through  a  reflex  action  of  the  nervous  system,  or  through 

1  At  the  meeting  of  the  French  Academy,  June  23,  1851,  M.  Blondlot  gave  the  history, 
and  an  account  of  the  post-mortem  examination,  of  a  Dog  that  had  lived  five  years  without 
the  passage  of  any  bile  into  the  intestinal  tube. 

'See  their  "  Verdauungssafte  und  Stoffwechsel,"  \\  114 — 209;  see  also  Lehmann'g 
"  Physiologischen  Chemie,"  2nd  edit.,  band  ii.  pp.  64 — 67 ;  and  "  Brit,  and  For.  Med.- 
rhir.  Rev.,"  vol.  xii.  pp.  187 — 191. 


INTESTINAL     DIGESTION. 


127 


FIG.  28. 


the  direct  stimulation  of  the  muscular  coat  of  the  duct  by  the  passage  of  alimen- 
tary matters  over  its  orifice,  we  have  at  present  no  means  of  satisfactorily  deter- 
mining. It  will  be  recollected  that  the  pill-bladder  is  usually  found  di'stendcd 
with  bile,  in  cases  of  death  from  starvation  (§  71),  notwithstanding  the  diminu- 
tion in  the  amount  actually  secreted. —  Of  the  bile  which  is  poured  into  the  intes- 
tinal tube,  by  far  the  greater  proportion  seems  to  be  reabsorbed  (§  117). 

118.  Besides  the  biliary  and  pancreatic  secretions,  there  is  poured  into  the 
upper  part  of  the  Intestinal  canal  a  fluid  secreted  in  its  own  walls,  which  has 
received  the  designation  of  Sumis  Entericus.  It  seems  not  improbable  that  the 
secretion  of  this  fluid  may  be  the  function 
of  the  Glands  of  Brunner,  which  are 
small  racemose  clusters  of  follicles  (Fig;. 
27),  imbedded  in  the  walls  of  the  duode- 
num, extending  also  to  the  commencement 
of  the  jejunum.  The  Intestinal  juice  ap- 
pears, from  the  researches  of  Bidder  and 
Schmidt,1  to  be  a  colourless  viscid  liquid, 
invariably  alkaline  in  its  reaction,  and 
containing  from  3  to  3£  per  cent  of  solid 
matter.  The  total  amount  daily  secreted 
in  Man  is  estimated  by  these  experi- 
menters at  about  7  oz. ;  the  rate  of  its 
secretion  seems  to  be  tn-ost  rapid  five  or 
six  hours  after  a  meal  j  and  its  quantity 
is  considerably  increased  shortly  after  the 
ingestion  of  fluid,  and  this  without  any 
diminution  in  the  proportion  of  its  solid 
constituents.  The  properties  of  this  se- 
cretion are  extremely  remarkable  }  for 

according  to  the  results  obtained  by  Bidder  and  Schmidt  and  their  pupil  Zander 
(which  are  now  admitted  by  Lehmann),  it  exerts  a  solvent  action  on  albuminous 
bodies  scarcely  inferior  to  that  of  the  gastric  juice,  and  a  power  of  converting 
starch  into  sugar  which  is  scarcely  less  than  that  of  saliva  or  pancreatic  fluid 

114.  The  fluid  of  the  Small  Intestines,  which  is  compounded  by  the  intermix- 
ture of  the  biliary  and  pancreatic  secretions,  with  the  salivary  and  gastric  fluids, 
and  with  the  secretion  of  the  intestinal  glandulae,  appears  to  possess  the  very 
peculiar  power  of  dissolving,  or  of  reducing  to  an  absorbable  condition,  alimentary 
substances  of  every  class ;  thus  possessing  more  of  the  character  of  a  '  universal 
solvent,'  than  either  of  these  secretions  has  in  its  separate  state.  It  completes 
the  conversion  of  starchy  into  saccharine  matter;  and  thus  enables  the  former  to 
supply  the  blood  with  an  important  pabulum  for  the  combustive  process,  which  is 
at  once  absorbed  into  the  blood-vessels.  It  emulsifies  the  oleaginous  matter,  and 
thus  renders  it  capable  of  being  introduced  into  the  lacteals.  And  it  not  only 
restores  to  the  state  of  solution,  those  albuminous  compounds,  which  may  have 
been  precipitated  by  the  addition  of  bile  to  the  product  of  gastric  digestion  j  but 
it  also  exerts  a  powerful  solvent  influence  upon  albuminous  substances  which  have 
not  been  submitted  to  the  previous  agency  of  the  gastric  fluid  (as  has  been  shown 
by  experimentally  introducing  pieces  of  meat,  through  a  fistulous  orifice,  directly 
into  the  duodenum),  and  it  thus  completes  the  solvent  process  which  had  been 
very  far  from  perfected  in  the  stomach.2  What  is  the  precise  share,  however,  of 

1  Op.  cit,  g|  260 — 282;  and  Lehmanu's  "  Physiologischen  Chemie,"  2nd  edit.,  band  ii., 
pp.  95—99. 

a  See  the  account  of  M.  Cl.  Bernard's  researches  in  the  "Amer.  Journ.  of  Med  Sci.," 
Oct.  1851,  p.  356;  Zander  "  De  Succo  Enterico,"  inaug.  diss.,  Dorpat,  1850.  and  Frerichs 
art.  Verdauung,  in  "Wagner's  Handworterbuch,"  band  iii. 


Portion  of  one  of  Brunner's  Glands,  from  tho 
Human  Duodenum. 


128  OF    FOOD,     AND    THE     DIGESTIVE     PROCESS. 

each  of  these  secretions,  in  producing  this  composite  result,  cannot  be  stated  with 
any  degree  of  certainty. — It  is  obvious  that  the  amount  of  each  kind  of  aliment- 
ary substance  that  can  be  thus  prepared  for  absorption  in  a  given  time,  will  vary 
with  the  amount  of  the  secretion  by  whose  agency  this  preparation  is  specially 
affected;  and  as  there  are  many  indications  that  the  quantity  of  each  that  is 
taken-up  in  absorption  is  limited,  and  that  it  bears  a  relation  to  the  wants  of  the 
system,  it  is  probable  that  the  amount  of  the  solvent  or  reducing  fluid  secreted 
by  each  glandular  apparatus,  is  regulated  (as  we  have  seen  it  to  be  in  the  case  of 
the  gastric  juice,  §  100)  by  the  demand  set-up  by  the  nutrient  operations,  rather 
than  by  the  amount  of  alimentary  matter  that  is  waiting  to  be  digested. —  The 
processes  of  digestion  and  conversion  are  probably  continued  during  the  entire 
transit  of  the  alimentary  matter  along  the  small  intestine,  and  at  the  same  time 
the  products  of  that  conversion  are  gradually  being  withdrawn  by  absorbent 
action ;  so  that,  by  the  time  it  reaches  the  caecum,  the  undigested  residue  con- 
tains little  else  than  the  innutritious  or  insoluble  components  of  the  food,  together 
with  the  excrementitious  portion  of  the  bile  and  of  other  secretions.  Up  to  this 
time,  the  contents  of  the  canal  have  an  alkaline  reaction ;  but  in  the  caecum  they 
again  become  acid;  and  it  has  been  supposed  that  this  change  depends  upon  the 
secretion  of  a  fluid  analogous  to  the  gastric  juice,  by  the  large  and  numerous 
tubular  glands  contained  in  the  parietes  of  this  part,  whereby  the  albuminous 
matters  still  undigested  might  be  more  completely  dissolved.  This  supposition 
appeared  to  derive  weight  from  the  fact,  that  the  caecum  is  peculiarly  large  in 
most  Herbivorous  animals,  the  'appendix  vermiformis'  being  also  of  greatly- 
increased  dimensions,  and  sometimes  double.  But  from  the  experiments  and 
observations  of  Blondlot,  it  seems  probable  that  the  acid  of  the  caecum  is  rather 
a  product  of  the  transformation  of  saccharine  substances  in  the  alimentary  canal, 
than  a  secretion  from  its  walls.1  Still,  as  this  lactic  acid  has  a  solvent  power  for 
albuminous  matters,  which  is  equal,  or  nearly  so,  to  that  exerted  by  hydrochloric 
acid,  it  is  by  no  means  impossible  that  it  may  be  subservient  to  the  completion 
of  the  digestive  process  in  the  cases  in  question ;  since,  the  larger  the  proportion 
of  the  aliment  composed  of  saccharine  matters,  the  greater  will  be  the  importance 
of  a  thorough  extraction  of  its  albuminous  constituents. 

115.  The  Intestinal  tube  is  furnished,  throughout  its  entire  length,  with  innu- 
merable simple  open  glandulae,  the  '  follicles  of  Lieberkiihn ;'  these  are  straight 
narrow  caeca,  standing  side  by  side,  with  very  little  intervening  substance  (except 
where  the  Peyerian  bodies  lie  amongst  them),  and  corresponding  in  length  with 
the  thickness  of  the  mucous  membrane.  Their  orifices  are  seen  in  the  interspaces 
between  the  villi,  where  they  are  so  closely  set-together  as  to  seem  like  the  aper- 
tures of  a  sieve ;  and  they  are  arranged  in  rings  around  the  Peyerian  glandulae 
(Fig.  ).  The  precise  nature  of  their  secretion  is  unknown ;  and  it  seems  not 
improbable  that,  notwithstanding  the  close  resemblance  which  they  bear  to  one 
another  in  anatomical  characters,  there  may  be  some  variety  of  function  among 
them.  Thus  it  is  likely  that  some  of  them  (like  the  mucous  glandulae  of  the 
stomach)  are  everywhere  destined  to  supply  a  protective  mucus;  whilst  some  of 
those  in  the  higher  part  of  the  intestinal  tube  may  furnish  the  succus  entericus ; 
and  some  of  those  in  the  lower  may  be  concerned  in  the  elimination  of  that  pecu- 
liarly faecal  matter,  which  seems  to  be  rather  an  excretion  from  the  blood,  than 
the  result  of  the  decomposition  of  any  constituents  of  the  food  (§  118).  [The 
muciparous  glands  are  found  both  in  the  small  and  large  intestines.  In  the  latter 
they  occupy  the  alveoli  of  the  reticulated  portion,  and  constitute  the  floor  of  those 
cavities.  They  are  white,  semi-transparent,  obscurely  lobulated,  and  provided 
with  an  excretory  aperture.  In  a  word,  they  correspond  so  completely  with  the 
sebiparous  glands  of  the  skin,  that  the  analogy  between  them  is  forced  on  the 
mind:  their  whiteness  and  semi-transparency  being  due  to  their  epithelial  struc- 
ture, as  is  the  case  with  the  sebiparous  glands. 

1  See  his  "  Traite"  analytique  de  la  Digestion,"  p.  103. 


INTESTINAL    DIGESTION. 


129 


The  nmciparous  glands  of  the  small  intestine,  according  to  the  same  observer, 
have  hitherto  escaped  observation,  or  have  been  confounded  with  irregular  patches 
of  aggregated  glands.  Mr.  Wilson 

has  found  them  only  in  the  lamellated  FIG.  29. 

mucous  membrane  (Fig.  29),  and 
principally  on  the  valvulse  conni- 
ventes.  In  this  portion  of  the  mem- 
brane they  seem  to  take  the  place  of 
simple  follicles,  which  latter  appear  to 
be  wholly  absent.  They  occur  in 
patches  as  large  as  a  lentil,  but  per- 
fectly flat,  and  are  identical  in  struc- 
ture with  the  mucous  membrane  of  the 
large  intestine,  consisting  of  a  reticular 
frame-work  and  alveoli.  Each  alveo- 
lus, which  is  polygonal,  and  mostly 
hexagonal  in  form  (Fig.  30),  contains 
a  inuciparous  gland,  which  forms  its 
floor,  and  is  supplied  with  a  central 
excretory  opening.  Around  the  cir- 
cumference of  the  glandular  patch  the 
reticular  structure  is  imperceptibly  lost  in  the  lamellae  of  the  lamellated  structure. 

The  surface  of  the  mucous  membrane  of  the  large  intestine  presents  this  most 
obvious  difference  from  that  of  the  stomach,  namely  smoothness  j  a  difference 
which  is  as  apparent  to  the  naked  eye,  as  to  the  eye  armed  with  the  microscope. 
When  examined  by  the  microscope,  there  is  observed  a  great  symmetry  of  the 


A  portion  of  the  mucous  membrane  of  the  je- 
junum lying  between  the  v-alvulae  conniventes, 
magnified  nineteen  times,  and  showing  the  la- 
mellated and  convoluted  form  of  villij  the 
breadth  of  the  lamellae  is  jls  °f  an  inch. 


FIG.  30. 


FIG.  31. 


A  portion  of  the  free  border  of  one  of  the 
valvulae  conniventes  of  the  jejunum,  magni- 
fied 19  times,  and  showing  an  alveolar  and 
glandular  structure,  not  hitherto  described. 
The  mode  of  transition  of  the  lamellated 
into  the  alveolar  structure  is  seen.  The  al- 
veoli measured  5^  of  an  inch  by  3^,  being 
as  large  as  those  of  the  stomach,  and  some- 
what larger  than  those  of  the  large  intestine ; 
the  septa  measured  between  £^  and  j^  of 
an  inch  in  width;  the  alveoli  were  shallow, 
and  contained  in  their  base  a  mucous  gland 
with  an  excretory  opening. 


A  portion  of  the  mucous  membrane  of  tfte 
large  intestine,  magnified  75  times.  The  al- 
veoli measured  ^^  of  an  inch  in  length,  by 
1%-G  in  breadth;  the  sep"ta  between  the  al- 
veoli measuring  ^-3-  of  an  inch  in  width. 
The  alveoli  are  less  regular  in  form  and  shal- 
lower than  those  of  the  stomach  ;  and  in  the 
bottom  of  each  is  a  gland  with  a  central 
excretory  aperture.  In  some  of  the  larger 
alveoli  there  are  two  glands 


reticulum  and  alveoli,  a  greater  breadth,  lesser  degree  of  prominence,  and  tiat- 
ness  and  evenness  of  the  septa,  and  an  elliptical  form  and  shallowness  of  the 
alveolar  spaces,  at  the  bottom  of  which  are  also  discovered  mucous  glands  helving 
a  central  excretory  aperture1  (Fig.  31). —  ED.] 


9 


1  [Vide  Wilson,  op.  cit,] 


130  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

116.  The  undigested  residue  of  the  food,  mingled  with  the  products  of  secre- 
tion that  have  been  poured  into  the  alimentary  canal,  gradually  acquires,  in  the 
large  intestine,  the  ordinary  consistency  of  Faeces,  through  the  continuance  of 
the  absorbent  process,  whereby  the  superfluous  fluid  is  removed.  The  condition 
of  this  residue  has  been  particularly  studied  by  Dr.  Rawitz,  who  examined  mi- 
croscopically the  products  of  the  artificial  digestion  of  different  kinds  of  aliment, 
and  the  contents  of  the  faeces  of  different  animals  that  had  eaten  the  same  arti- 
cles. "  The  general  results  of  his  examinations,  as  regards  animal  food,  show 
that  the  muscular  tissue  breaks  up  into  its  constituent  fasciculi,  and  that  these 
again  are  divided  transversely ;  gradually  the  transverse  striae  become  indistinct 
and  then  disappear;  and  finally  the  sarcolemma  seems  to  be  dissolved,  and  no 
trace  of  the  tissue  can  be  found  in  the  chyme,  except  a  few  fragments  of  fibres. 
These  changes  ensue  most  rapidly  in  the  flesh  of  fish  and  hares,  less  rapidly  in 
that  of  poultry  and  other  animals.  The  fragments  of  muscular  tissue  which 
remain  after  the  continued  action  of  the  digestive  fluid,  do  not  appear  to  undergo 
any  alteration  in  their  passage  through  the  rest  of  the  intestinal  canal;  for  similar 
fragments  may  be  found  in  faeces,  even  twenty-four  hours  after  the  introduction 
of  the  meat  into  the  stomach.  The  cells  of  cartilage  and  fibro-cartilage,  except 
those  of  fish,  pass  unchanged  through  the  stomach  and  intestines,  and  may  be 
found  in  the  faeces.  The  interstitial  tissues  of  these  structures  are  converted  into 
pulpy  textureless  substances  in  the  artificial  digestive  fluid.1  Fatty  matters  also 
are  unchanged;  fat-cells  are  sometimes  found  quite  unaltered  in  the  faeces;  and 
crystals  of  cholesterin  may  usually  be  obtained  from  faeces,  especially  after  the 
use  of  pork-fat. — As  regards  vegetable  substances,  Dr.  Rawitz  states  that  he  fre- 
quently found  large  quantities  of  cell-membranes  unchanged  in  the  faeces;  also 
starch-cells,  deprived  of  only  part  of  their  contents.  The  green  colouring  prin- 
ciple, chlorophyll,  was  usually  unchanged.  The  walls  of  the  sap-vessels  and 
spiral  vessels  were  quite  unaltered  by  the  digestive  fluid,  and  were  usually  found 
in  large  quantities  in  the  faeces;  their  contents,  probably,  were  removed."2 — 
Besides  the  undigested  residue  of  the  food,  the  microscope  enables  us  to  recog- 
nize the  brown  colouring-matter  of  the  bile,  epithelium-cells  and  mucus-corpus- 
cles, and  various  saline  particles,  especially  those  of  the  ammonio-magnesian 
phosphate,3  whose  crystals  are  well-defined ;  most  of  which  are  derived  from  the 
secretions. —  The  quantity  of  faecal  discharge  which  is  daily  passed  by  an  adult, 
seems  to  average  from  4  to  6  oz. ;  but  this  contains  75  per  cent  of  water;  so  that 
the  dry  solid  matter  thus  evacuated  is  not  above  1  oz.  or  1J  oz.  Of  this,  from 
23  to  31  £  per  cent  (the  proportion  being  highest  when  an  abundant  meat  diet 
has  been  consumed)  consists  of  an  Inorganic  ash;  the  composition  of  which  is 
stated  by  Enderlin  to  be  as  follows :  — 

1  It  has  been  pointed-out  to  the  Author  by  his  friend  Mr.  Quekett,  that  elastic  fibres  are 
occasionally  to  be  met  with  in  the  Human  faeces,  which  present  an  appearance  of  trans- 
verse division  (probably  resulting  from  incipient  decomposition)  closely  resembling  that 
which  is  normal  in  the  ligamentum  nuchae  of  the  Giraffe.     So  distinct,  indeed,  does  the 
transverse  division  then  become,  that  these  fibres,  when  peculiarly  abundant  (as  they  are 
in  the  faeces  of  persons  who  have  for  some  time  been  living  upon  mutton-chops,  and  have 
not  put  aside  the  segment  of  the  aorta  which  each  chop  includes),  have  actually  been  mis- 
taken for  a  Confervoid  growth  in  the  faeces. 

2  The  above  passage  is  quoted  from  Messrs.  Kirkes  and  Paget's  "  Hand-book  of  Physio- 
logy," in  which  it  is  derived  from  the  Memoir  by  Dr.  Rawitz  "  Ueber  die  Einfachen  Nah- 
rungsmittel,"  Breslau,  1846.  —  See  also  the    Inaugural  Theses  of  Wehsarg   and  Ihring 
(Giessen,  1853),  of  which  an  analysis  is  given  in  the  "Brit,  and  For.  Med.-Chir.  Review," 
vol.  xiv.,  p.  528. 

3  The  presence  of  this  salt  in  the  faeces  was  maintained  by  Schonlein  to  be  pathognomonio 
of  typhus ;  but  more  recent  and  correct  observations  have  shown  that  this  view  is  fallacious. 
Crystals  of  this  salt  sometimes  occur  in  perfectly  normal  faeces ;  and  in  those  cases  in  which 
the  secreted  fluids  and  the  contents  of  the  intestine  readily  undergo  decomposition,  as  in 
typhus,  cholera,  and  certain  forms  of  dysentery,  they  are  found  in  large  numbers  and  of 
considerable  size, 

"Ann.  de  Chem.  und  Pharm.,"  1844. 


INTESTINAL    DIGESTION:  —  FAECES.  131 

Alkaline  chlorides  and  sulphates  ...........................     1-367)  a  ,  ,,    .    , 

Bibasic  phosphate  of  soda.....  ..............................     2-633  }  Soluble  m  water' 

Phosphates  of  lime  and  magnesia  ............................   80-372"*, 


Silica  ..............................................................     7-940 

The  potash  generally  predominates  greatly  over  the  soda,  but  especially  when  the 
diet  has  chiefly  consisted  of  muscular  flesh.  The  study  of  the  composition  of 
the  Organic  portion  of  the  Faeces  is  attended  with  so  much  difficulty  and  un- 
pleasantness, that  it  has  hitherto  been  scarcely  prosecuted  systematically.  Ac- 
cording to  the  recent  enquiries  of  Dr.  Marcet,1  healthy  human  excrements  contain, 
—  1.  A  peculiar  crystalline  substance,  having  an  alkaline  reaction,  containing  both 
nitrogen  and  sulphur,  fusing  at  about  203°,  and  at  a  higher  temperature  burning 
away  without  inorganic  residue;  this  he  proposes  to  call  Excretine  ;  2.  A  fatty 
acid,  having  the  properties  of  Margaric  acid,  but  not  constantly  present;  3.  A 
colouring  matter,  similar  to  that  of  blood  and  urine  ;  4.  A  light  granular  colour- 
less substance,  sparingly  soluble  in  ether,  fusible  by  heat,  and  burning  with  a 
bright  fuliginous  flame,  leaving  a  white  residue  composed  of  phosphate  of  potash  j 
this  is  probably  a  combination  of  phosphate  of  potash  with  a  pure  organic  sub- 
stance ]  5.  An  acid  olive-coloured  substance  of  a  fatty  nature,  termed  Excretolic 
acid  ;  this  is  probably  united  in  faeces  with  excretine  or  a  basic  substance  closely 
allied  to  it.  Neither  butyric  nor  lactic  acid  could  be  discovered  in  healthy  Human 
excrement  ;  although  the  former  presents  itself  in  the  excrements  of  Carnivorous 
Mammalia,  which  contain  also  a  substance  allied  in  its  nature  to  excretine,  but 
not  identical  with  it. 

117.  Of  the  degree  in  which  the  Bile,  as  a  whole,  normally  enters  into  the 
composition  of  the  faeces,  it  is  difficult  to  speak  with  precision.     Its  principal 
constituents  can  easily  be  recognized  in  the  upper  part  of  the  small  intestine  ;  but 
the  further  we  descend  in  the  intestinal  canal,  the  less  of  them  do  we  meet-with; 
and  in  the  contents  of  the  large  intestine,  and  in  the  evacuated  faeces,  they  are 
seldom  to  be  discovered.     How  far  this  result  depends  upon  their  removal  from 
the  alimentary  canal  by  re-absorption,  and  how  far  upon  the  loss  of  their  charac- 
teristic properties  by  decomposition,  cannot  be  stated  with  certainty.     That  the 
colouring-matter  of  the  fseces  is  in  great  part  derived  from  the  bile,  is  shown  by 
their  paleness  when  that  secretion  is  not  duly  poured  into  the  intestinal  tube. 
And  it  is  probable  that  the  peculiar  fatty  substances  just  described,  are  products 
of  the  metamorphosis  of  its  oleaginous  and  resinous  matters.     The  similarity 
which  has  been  found  to  exist  between  the  odour  of  certain  components  of  putre- 
fying bile,  and  that  of  faeces,  has  led  Prof.  Valentin  to  suppose  that  the  matter 
which  gives  to  the  latter  their  characteristic  smell,  is  entirely  derived  from  de- 
composing bile.     We  shall  presently  see,  however,  that  other  sources  of  this 
matter  probably  exist  (§  118)  ;  and  the  recent  researches  of  Bidder  and  Schmidt 
upon  the  amount  of  sulphur  in  the  faeces,  appear  to  show  that  not  above  one- 
eighth  of  the  solid  matter  of  the  bile  is  normally  excreted  under  this  form.     The 
indications  of  the  presence  of  bile  are  more  distinct,  however,  when  the  faeces 
have  remained  for  only  a  short  time  in  the  large  intestine,  and  when  there  has 
consequently  been  less  time  for  its  re-absorption.     In  the  faecal  discharges  which 
result  from  the  action  of  mercurials,  large  quantities  of  biliary  matter  may  be 
detected,  very  little  changed. 

118.  Although  it  cannot  be  stated  with  certainty,  what  is  the  precise  portion 
of  the  Glandular  apparatus  connected  with  the  Intestinal  canal,  which  is  con- 
cerned in  the  elimination  of  that  peculiarly  putrescent  matter  which  gives  to  the 
faeces  their  characteristic  odour,  yet  it  may  be  stated  almost  with  certainty,  that 
this  matter  is  not  derived  from  the  decomposition  of  the  undigested  residue  of 
the  food.     For,  in  the  first  place,  this  residue  consists  of  matters  whose  very 

1  "Proceedings  of  the  Royal  Society,"  June  15,  1854. 


132  OF    FOOD,    AND    THE    DIGESTIVE    PROCESS. 

inaptitude  for  undergoing  chemical  change  is  the  source  of  their  indigestibility : 
and  it  is  scarcely  possible,  therefore,  to  imagine  that  in  so  short  a  period  they 
should  acquire  a  character  so  peculiarly  offensive.  But  further,  we  observe  that 
fsecal  matter  is  still  discharged,  even  in  considerable  quantities,  long  after  the 
intestinal  tube  has  been  completely  emptied  of  its  alimentary  contents.  We  see 
this  in  the  course  of  many  diseases,  when  food  is  not  taken  for  several  days, 
during  which  time  the  bowels  have  been  completely  emptied  of  their  previous 
contents  by  repeated  evacuations.  Sometimes  a  copious  flux  of  putresoent  matter 
continues  to  take  place  spontaneously;  whilst  it  is  often  produced  by  the  agency 
of  purgative  medicine.  The  "  colliquative  diarrhoea,"  which  frequently  comes 
on  at  the  close  of  exhausting  diseases,  and  which  usually  precedes  death  by  star- 
vation, appears  to  depend,  not  so  much  upon  a  disordered  state  of  the  secreting 
organs  themselves,  as  upon  the  general  disintegration  of  the  solids  of  the  body, 
which  calls  them  into  extraordinary  activity,  for  the  purpose  of  separating  the 
decomposing  matter  which  has  accumulated  in  it  to  a  most  unusual  amount  (§  72). 
—  These  views  (which  have  long  been  taught  by  the  Author)  derive  a  remarkable 
confirmation  from  the  experiments  of  Prof.  Liebig  on  the  production  of  artificial 
fsecal  matter.  For  he  has  ascertained  that  if  albuminous  or  gelatinous  compounds 
be  heated  with  solid  hydrate  of  potash,  and  the  heat  be  continued  until  the 
greater  part  or  the  whole  of  the  nitrogen  has  been  dissipated  as  ammonia,  and 
liydrogen  begins  to  be  given-off,  the  residue,  when  supersaturated  with  dilute 
•sulphuric  acid,  and  distilled,  yields  a  liquid  containing  acetic  and  butyric  acids, 
and  possessing  in  a  very  intense  degree  the  peculiar  and  characteristic  odour  of 
human  faeces.  The  odour  varies  according  to  the  substance  employed ;  and  in 
this  way  all  varieties  of  faecal  smell  may  be  obtained.  As  the  action  of  caustic 
potash  at  a  high  temperature  is  simply  a  limited  or  incomplete  oxidation  or  com- 
bustion, this  curious  result  confirms  the  view  which  had  been  previously  put-forth 
by  Prof.  Liebig,  that  the  proper  faecal  matter  is  the  product  of  the  imperfect  oxi- 
dation which  a  portion  of  the  histogenetic  constituents  of  the  food  undergo  in 
the  course  of  their  retrograde  metamorphosis,  being  comparable  to  the  soot  or 
lamp-black  of  a  furnace  or  lamp.  It  is  further  urged  by  him,  that  the  condition 
of  the  faeces  differs  in  many  particulars  from  that  of  substances  in  a  state  of  fer- 
mentation or  putrefaction ;  that  their  peculiar  odour  is  entirely  unlike  any  that 
is  generated  by  the  ordinary  decomposition  of  organic  compounds,  whether  azotized 
or  non-azotized ;  and  that,  by  contact  with  air,  they  themselves  undergo  a  sort  of 
fermentation  or  putrefaction,  in  which  their  peculiar  foetor  disappears, — a  fact,  as 
he  justly  remarks,  which  is  full  of  significance.1  This  view  is  of  great  practical 
importance ;  for  if  it  be  true  that  the  intestinal  canal  receives  and  discharges  the 
products  of  the  secreting  action  of  a  glandular  apparatus,  whose  special  function 
is  the  elimination  of  certain  products  of  decomposition  from  the  blood,  the  fa- 
cility with  which  we  can  stimulate  this  to  increased  action  by  certain  kinds  of 
purgative  medicine,  gives  us  a  most  valuable  means  of  augmenting  its  depurative 
action.  Seeing,  as  no  observant  Medical  Practitioner  can  avoid  doing,  how  fre- 
quently Nature  herself  employs  this  means  of  eliminating  morbific  matter  from 
the  system, — as  is  shown  by  the  immense  relief  often  given  by  an  attack  of  diar- 
rhea,—  we  may  look  upon  this  apparatus  as  one  which,  like  the  Liver,  the  Kid- 
ney, or  the  Skin,  may  frequently  with  propriety  be  stimulated  by  medicines  that 
have  a  special  action  upon  it,  and  one  through  which  some  morbific  matters  may  be 
gotten  rid  of  more  certainly  and  more  speedily  than  through  any  other  channel. — 
It  is  not  intended  by  these  observations  to  encourage  the  system  of  violent  and 
indiscriminate  purgation ;  but  to  show  that  purgatives,  judiciously  administered, 
often  constitute  our  best  means  of  eliminating  injurious  matters  from  the  system 

1  Sec  Prof.  Liebig's  "Animal  Chemistry,"  3rd  edit.,  pp.  148—154. 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         133 

CHAPTER  IV. 

OP    ABSORPTION    AND    SANGUIFICATION. 
1.    Of  Absorption  from  the  Digestive  Cavity.  t 

119.  So  long  as  the  Alimentary  matter  remains  in  the  Digestive  cavity,  how- 
ever perfect  may  be  its  state  of  preparation,  it  is  as  far  from  being  conducive  to 
the  nutrition  of  the  system,  as  if  it  were  in  contact  with  the  external  surface. 
It  is  only  when  absorbed  into  the  vessels,  and  carried  by  the  circulating  current 
through  the  very  substance  of  the  body,  that  it  becomes  capable  of  being  appro- 
priated by  its  various  tissues  and  organs.  In  Man,  as  in  nearly  all  vertebrated 
animals,  a  set  of  vessels  is  interposed  between  the  walls  of  the  intestine  and  the 
sanguiferous  system;  for  the  purpose,  as  it  would  seem,  of  taking-up  certain 
components  of  the  nutritive  matter,  of  which  part  at  least  are  not  in  a  state  of 
perfect  solution,  and  of  preparing  them  for  being  introduced  into  the  current  of 
the  blood.  These  are  the  Absorbents  of  the  intestinal  walls ;  of  which  those  that 
are  found,  after  the  performance  of  the  digestive  process,  to  contain  the  white 
opalescent  fluid  known  as  *  chyle/  are  distinguished  as  lacteals;  while  the  re- 
mainder, like  the  absorbents  of  the  system  generally,  are  known  as  lymphatics. 
The  distinction  is  a  purely  artificial  one ;  for  the  l  lacteals '  are  the  '  lymphatics ' 
of  those  parts  of  the  intestinal  walls  which  they  supply,  as  is  shown  by  the  fact 
that,  during  the  intervals  of  the  digestive  process,  they  contain  a  transparent  fluid 
in  all  respects  similar  to  the  'lymph'  of  other  parts. — The  Absorbents  form  a 
minute  plexus  beneath  the  mucous  lining  of  the  alimentary  canal  along  its  whole 
extent ;  but  in  the  small  intestine  they  enter  the  villi,  at  the  extremities  of  which, 
indeed,  they  may  be  said  to  commence.  Those  only  are  entitled  to  the  designa- 
tion of  '  lacteals/  which  originate  from  the  intestinal  canal  below  the  point  at 
which  the  biliary  and  pancreatic  ducts  pour  their  contents  into  it ;  for  above  that 
point,  the  fatty  constituents  of  the  alimentary  matter  are  not  in  a  state  of  suffi- 
ciently fine  division  to  enter  them ;  and  the  absorbed  fluid  is  consequently  pellu- 
cid, instead  of  possessing  the  milky  aspect.  Thus,  then,  we  are  to  consider  the- 
lacteal  portion  of  the  Absorbent  system,  to  be  that  part  of  it  which  is  specially 
adapted,  by  its  prolongation  into  the  villi,  for  the 
reception  of  an  oleaginous  fluid ;  which  we  shall  FIG.  32. 

presently  see  to  be  taken-up  from  the  contents  of 
the  alimentary  canal,  and  to  be  prepared  for  en- 
trance into  the  absorbents,  by  the  epithelium-cells 
at  the  radical  extremities  of  those  organs  (§  121). 

120.  The  Villi  are  extensions  of  the  mucous 
lining  of  the  Intestinal  canal,  which  thickly  beset 
its  surface  from  the  pyloric  orifice  to  the  caecum, 
that  is,  through  the  entire  length  of  the  Small  In- 
testine, to  which  they  are  limited  in  Man.  They 
have  usually  somewhat  the  form  of  the  finger  of  a 
glove,  being  sometimes  nearly  cylindrical,  some- 
times rather  conical,  whilst  they  not  unfrequently 
become  flattened  and  extended  at  the  base,  so  that 
two  or  more  coalesce  (Fig.  32).  Their  length 
varies  from  l-4th  to  1-3 rd  of  a  line,  or  even  more; 
and  the  broad  flattened  kinds  are  about  l-6th  to  villi  of  the  Human  Intestine,  ™t 
l-8th  of  a  line  in  breadth. —  In  the  upper  part  of  their  capillary  plexus  injected 


134 


OF    ABSORPTION    AND    SANGUIFICATION. 


the  small  intestine,  where  they  are  most  numerous,  it  has  been  calculated  by 
Krause  that  there  are  not  less  than  from  50  to  90  in  a  square  line ;  and  in  the 
lower  part  from  40  to  70  in  the  same  area  (Fig.  33). — Each  villus  appears  ordi- 
narily to  contain  but  a  single  lacteal  tube,  which  occupies  its  centre ;  in  the  larger 
villi,  however,  two  or  even  more  trunks  are  sometimes  discernible  (Fig.  35,  A). 
The  mode  in  which  this  tube  commences,  near  the  extremity  of  the  villus,  has 
not  yet  been  precisely  made-out :  according  to  the  recent  observations  of  Prof. 
Bruch,1  there  is  a  caecal  ampulla,  or  excavation  in  the  tissue,  at  the  extremity  of 
each  villus,  wherein  its  lacteal  trunk  commences;  and  in  the  broad  villi  which 
contain  two  lacteals,  each  has  its  own  ampulla.  Each  villus  is  also  furnished 
with  a  minute  plexus  of  capillary  vessels,  which  lies  near  its  surface  (Fig.  34) ; 
but  the  particular  arrangement  of  the  vessels,  the  form  of  the  plexus,  &c.,  differ 
considerably  in  different  animals,  and  even  in  different  portions  of  the  intestine 
of  the  same  individual.  From  the  facts  to  be  presently  stated,  it  will  be  obvious 


[FiG.  33. 


[FiG.  34. 


A  section  of  the  Ileum,  inverted  so  as  to  show  the 
appearance  and  arrangement  of  the  villi  on  an  ex- 
tended surface,  as  well  as  the  follicles  of  Lieberkiihn  ; 
the  whole  seen  under  the  microscope.  A  close  exa- 
mination of  this  cut  will  show  a  great  number  of 
black  points  in  the  spaces  between  the  projections  of 
villi :  these  are  the  follicles  of  Lieberkiihn.] 


Vessels  of  an  Intestinal  Villu» 
of  a  Hare,  from  a  dry  prepara- 
tion by  Dollinger :  a,  a,  veins 
filled  with  white  injection;  6,  b, 
arteries  injected  red.] 


that  these  blood-vessels  are  not  less  actively  concerned  in  the  absorbent  functions, 
than  are  the  lacteals  themselves;  and  there  is  evidence,  moreover,  that  the 
circulation  of  blood  through  them  is  essential  to  the  introduction  of  chyle 
into  the  absorbents.2  Hence  some  have  supposed  that  the  contents  of  the  lac- 

1  '  Beitrage  zur  Anatomic  und  Physiologic  der  Dunndarm-Schleimhaut,'  in  "  Siebold  and 
Solliker's  Zeitschrift,"  April,  1853. 
'•  See  especially  the  experiments  of  Mr.  Fenwick  in  the  "  Lancet,"  Jan.  and  Feb.,  1845. 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         135 

teals  are  first  imbibed  by  the  blood-vessels,  and  are  afterwards  eliminated  from 
them  by  a  kind  of  glandular  action  on  the  part  of  the  absorbents;  but  of  this 
there  is  no  adequate  evidence;  and  it  seems  more  probable  that  the  constant 
supply  of  blood  is  required  for  that  peculiar  cell-action,  to  which  the  selection  of 
the  materials  of  the  chyle  is  due.  —  The  curious  fact  has  recently  been  substan- 
tiated by  Prof.  Kolliker,1  that  the  villi  contain  numerous  muscular  fibre-cells,  and 
that  they  present  themselves  in  very  different  degrees  of  contraction  and  exten- 
sion. This  observation  confirms  the  statement  formerly  made  by  M.  Lacauchie2 
as  to  the  existence  of  contractile  tissue  in  the  villi,  which  statement  was  based 
on  the  contraction  which  he  had  observed  them  to  undergo  after  their  removal 
from  the  body;  and  also  the  yet  more  remarkable  assertion  of  MM.  Gruby  and 
Delafond,  that  rhythmical  movements  of  contraction  and  extension  in  different 
directions  take  place  in  the  villi  whilst  absorption  is  going-on,3  which  have  an 
important  influence  on  the  propulsion  of  the  fluids  contained  within  their  vessels. 
121.  When  the  Villi  are  examined  at  such  a  period  after  a  meal  containing 
oleaginous  matters,  as  has  sufficed  for  its  partial  digestion,  their  lacteals  are  seen 
to  be  turgid  with  chyle  (Fig.  35,  A);  and  the  extremity  of  each  lacteal  appears 

FIG.  35. 


Extremity  of  Intestinal  Villas :  seen  at  A,  during  absorption,  and  showing  absorbent 
cells  and  lacteal  trunks,  distended  with  chyle;  at  B,  during  interval  of  digestion,  show- 
ing the  supposed  peripheral  network  of  lacteals. 

to  be  imbedded  in  a  collection  of  globules  presenting  an  opalescent  appearance, 
which  gives  to  the  end  of  the  villus  a  somewhat  mulberry-like  form.  It  was 
supposed  by  Prof.  Goodsir,4  by  whom  this  appearance  was  first  observed,  that 
these  globules  are  cells  developed  within  the  basement-membrane,5  during  the 
act  of  absorption,  from  what  he  considered  to  be  granular  germs  visible  in  the  same 
situation  during  the  intervals  of  the  process  (B)  ;  and  that  these  cells,  drawing 
into  themselves  during  their  growth  certain  of  the  nutritive  materials  contained 
in  the  intestinal  canal,  are  thus  the  real  agents  in  the  selection  of  the  substances 
which  are  to  be  introduced  into  the  lacteals,  delivering  them  to  these,  by  the 
rupture  or  deliquescence  of  their  walls,  so  soon  as  their  own  term  of  life  is  ended. 
It  was  further  held  by  Prof.  Goodsir,  that  the  epithelium-cells  covering  the  ex- 
tremities of  the  villi  fall-off  during  the  process  of  absorption,  so  as  to  leave"fhe 
villi  more  free  to  imbibe  the  fluids  in  contact  with  their  surface;  and  thus  that 
a  new  set  of  absorbent  cells  is  developed  with  every  recurrence  of  the  act  of  ab- 
sorption, and  a  new  set  of  protective  epithelium-cells  in  the  subsequent  interval. 
These  views,  however,  though  correctly  indicating  the  fact  that  the  elements  of 
chyle  are  introduced  into  the  lacteals  by  the  intermediation  of  cells,  have  been  shown 

1  "  Mikroskopische  Anatomie,"  Band.  ii.  \  168. 

a  "Etudes  Hydrotomiques  et  Micrographiques,"  Paris,  1844,  p.  50. 

3  "Comptes  Rendus,"  1842,  p.  1199;  and  1843,  p.  1195. 

4  "Edinb.  New  Phil.  Journ.,"  July,  1842;  and  "Anatomical  and  Pathological  Observa- 
tions," pp.  5 — 10. 

*  The  epithelium-cells  of  the  villi  may  frequently  be  observed  to  be  connected  at  their 
free  extremities  by  something  like  a  continuous  membrane;  and  it  was  doubtless  this, 
which  was  mistaken  by  Prof.  Goodsir  for  the  proper  basement-membrane  that  underlies  the 
epithelium-cells. 


136 


OF    ABSORPTION    AND    SANGUIFICATION. 


Extremity  of 
during  absorption  :  —  a,  marginal  layer 
of  epithelium-cells  ;  b,  epithelium-cells 
turgid  with  oleaginous  matter;  c,  adhe- 
rent oil-globules. 


to  be  erroneous  so  far  as  regards  the  nature  of  these  cells ;  for  several  excellent 
observers'  now  agree  in  regarding  them  as  the  proper  epitheliurn-cells  of  the  villi, 

which  are  not  thrown  off,  as  Prof.  Goodsir  be- 
FIG.  36.  lieved,  but  so  completely  change  their  aspect 

in  consequence  of  the  imbibition  of  oleaginous 
fluid  (Fig.  36),  that  they  cease  to  be  recogniza 
ble  as  such,  unless  their  intermediate  stages  be 
traced.  —  It  may,  then,  be  stated  with  some 
confidence,  that  the  epithelium-cells  covering 
the  extremities  of  the  villi  are  the  real  instru- 
ments in  the  selection  and  absorption  of  the 
materials  of  the  chyle;  and  that,  drawing 
these  into  their  own  cell-cavities,  they  subse- 
quently deliver  them  up  to  the  lacteals,  by 
which  they  are  carried  towards  the  centres  of 
the  circulation.  And  further,  that  although 
it  may  be  true  that  the  epithelium-cells  are 
sometimes  cast-off  in  considerable  quantities, 
in  certain  disordered  states  of  the  mucous 
membrane  (as  in  cholera),  yet  that  there  is  no 
evidence  of  its  being  thus  exuviated  in  health  j 
the  appearances  which  have  led  to  the  idea 
Intestinal  Vilhi*  that  such  exuviation  is  a  regular  occurrence, 
being  partly  dependent  upon  the  facility  with 
which  the  villi  are  denuded  of  them  by  mace- 
ration or  manipulation. 

[Before  considering  the  absorption  that  takes 
place  through  the  walls  of  the  blood-vessels,  it  will  be  right  to  consider  what  13 
its  essential  nature,  and  how  far  physical  principles  can  be  applied  to  its  elucida- 
tion. It  was  formerly  believed  that  all  absorption  took  place  by  the  open  mouths 
of  vessels  presented  to  the  fluid  to  be  received ;  but  anatomical  investigation  has 
shown  that  in  no  instance  are  thin  fluids  thus  taken  into  the  system,  but  that  the 
transmission  always  takes  place  through  some  tissue  of  a  membranous  character. 
As  all  animal  tissues  are  more  or  less  porous,  they  exhibit  the  phenomena  of  im- 
bibition. Many  of  the  tissues  of  the  body  are  dependent  for  the  performance  of 
their  functions  on  their  power  of  imbibing  water;  as  is  seen  in  the  case  of  the 
cornea,  which  owes  its  brilliancy  to  this  faculty. 

The  physical  conditions  of  Imbibition  are  briefly  these :  —  When  any  porous 
substance,  not  already  saturated,  is  brought  in  contact  with  a  liquid,  which  has 
such  a  molecular  attraction  for  its  particles  as  to  be  capable  of  "  wetting"  it,  the 
liquid  is  imbibed  by  it,  and,  provided  the  force  of  imbibition  is  strong  enough, 
is'speedily  distributed  through  the  whole  mass.  The  force  with  which  the  fluid 
is  distributed  depends  partly  upon  the  attraction  existing  between  the  particles  of 
the  solid  and  those  of  the  fluid,  and  partly  upon  the  size  of  the  capillary  pores  or 
canals. 

Temperature  has  also  a  remarkable  influence,  elevation  notably  increasing  th«, 
rapidity  of  transmission,  whilst  depression  as  greatly  diminishes  it. 

Another  circumstance  bearing  upon  the  phenomena  of  imbibition,  is  the  mutua 
diffusion  of  liquids.  If  a  saline  solution  contained  in  a  wide  open-mouthed  viai 
be  placed  in  a  larger  one  containing  pure  water,  the  saline  solution  will  diffuse 
itself  through  the  water  until  both  are  of  equal  density.  The  rapidity  of  tho 
diffusion,  however,  will  depend  on  several  circumstances.  Different  fluids  possess 

1  See  MM.  Gruby  and  Delafond,  in  "  Comptes  Rendus,"  Juin  5,  1843 ;  Kuss,  in  "  Gaz. 
He'd,  de  Strasbourg,"  No.  2,  1846;  E.  H.  Weber,  in  "  Miiller's  Archiv.,"  1847;  Kolliker, 
«« Mikroskopische  Anatomic,"  Band  ii.  \  169;  and  Bennett,  in  "Edinb.  Monthly  Journal," 
March,  1852,  p.  283. 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         137 

this  property  of  diffusibility  in  varying  degrees ;  thus,  when  solutions  of  the  fol- 
lowing substances  were  employed,  of  the  strength  of  20  parts  to  100  of  water, 
the  relative  quantities  diffused  in  a  given  time  were  as  follows :  — 

Chloride  of  sodium 58-68  I  Crystallized  cane-sugar 26-74 

Sulphate  of  magnesia 27-42  |  Starch-sugar  (glucose) 26-94 

Nitrate  of  soda 51-56     Gum-arabic 1324 

Sulphate  of  water 69-32  |  Albumen 3-08 

The  low  diffusibility  of  albumen  is  remarkable,  obviously  tending  to  the  reten- 
tion of  the  serous  fluids  within  the  tissues.  And  it  is  further  to  be  observed, 
that  if  albumen  be  held  in  solution  with  common  salt,  or  urea,  the  latter  will 
diffuse  away  from  the  albumen  and  leave  it  behind,  thus  favouring  their  escape 
from  the  economy  while  the  albumen  is  retained. 

Both  of  these  agencies  —  the  imbibition  of  liquids  by  porous  bodies  and  the 
mutual  diffusion  of  fluids  —  appear  to  be  concerned  in  the  production  of  the  phe- 
nomena of  Endosmose  and  Exosmose,  or  a  "  flowing -in"  and  a  "flowing-out" 
The  term  Endosmose,  however,  is  at  present  applied  to  the  stronger  current,  which- 
ever be  its  direction. 

The  phenomena  of  Endosmose  are  as  follows:  —  If  a  small  animal  bladder  con- 
taining a  solution  of  sugar,  or  some  organic  fluid,  be  immersed  in  water,  it  will 
be  found  that  the  w^ter  will  pass  through  to  become  mingled  with  the  contained 
fluid,  while  a  portion  of  the  contents  of  the  bladder  will  transude  to  the  water 
on  the  outside.  To  the  first  current  Dutrochet  gave  the  name  Endosmose  (fvSov, 
within,  cocr^ioj,  impulse),  and  to  the  latter  Exosmose.  The  rapidity  of  the  current, 
in  the  main,  depends  on  the  greater  original  difference  in  density  of  the  two 
fluids,  and  the  interchange  will  continue  until  the  two  are  of  the  same,  or  nearly 
the  same,  density.  As  a  general  rule  the  current  sets  most  strongly  from  the  rarer 
to  the  denser  fluid ;  but  much  depends  upon  the  affinity  which  they  individually 
have  for  the  septum  :  thus,  when  water  and  alcohol  are  on  the  opposite  sides  of  an 
animal  membrane,  the  current  is  most  rapid  from  the  denser  to  the  rarer  fluid^ 
because  water  has  a  stronger  affinity  for  the  membrane  than  alcohol  has.  The 
reverse  takes  place  when  the  septum  is  composed  of  caoutchouc. 

If,  now,  we  suppose  two  fluids  on  the  opposite  side  of  an  animal  membrane^ 
then  it  will  be  found  that  the  one  which  has  the  greatest  "  wetting"  power  will 
occupy  the  pores  of  the  membrane ;  and  should  it  at  the  same  time  be  diffusible 
through  the  opposite  fluid,  it  will  distribute  itself  through  it,  and  be  removed 
with  a  rapidity  commensurate  with  its  diffusive  power  —  "just  as  oil  continues  to 
ascend  through  the  capillary  channels  in  the  wick  of  a  lamp,  so  long  as  it  is  being 
dissipated  by  the  combustive  process  at  its  summit."  It  will  thus  be  seeu  that 
the  direction  of  the  current  will  depend  upon  the  affinities  of  the  fluids  f  /r  the 
septum,  whilst  its  force  will  depend  upon  the  diffusive  power  of  the  liquid  j. 

The  endosmotic  current  then  depends  upon  the  affinity  of  the  fluids  for  the 
membrane,  that  which  has  the  greatest  affinity  determining  the  direction, — as, 
in  the  case  of  the  bladder  mentioned  above,  the  current  will  be  most  rapid  from 
the  water  to  the  saccharine  solution.  But  at  the  same  time  the  saccharine  solu- 
tion will  diffuse  itself  through  the  water  contained  in  the  capillary  pores,  and 
will  thus  reach  the  opposite  side  of  the  membrane,  producing  the  feebler  or 
exosmotic  current. 

Professor  Graham1  attributes  the  phenomena  above  described  to  the  (l  osmotic 
force,"  the  power  by  which  liquids,  &c.,  are  impelled  through  moist  membrane  and 
other  porous  septa,  in  experiments  of  endosmose  and  exosmose.  Diffusion  and 
capillarity  he  believes  to  be  insufficient  to  account  for  it. 

"  The  nature  and  modus  operandi  of  the  chemical  action  producing  osmose 
remain  still  very  obscure.  Salts  and  other  substances,  capable  of  determining 
a  large  osmose,  are  all  chemically  active  substances,  while  the  great  mass  of  neu- 

1  Bakerian  lecture  on  Osmotic  force,  by  Prof.  Graham,  F.  R.  S. 


138  OF    ABSORPTION    AND    SANGUIFICATION. 

tral  organic  substances,  and  perfectly  neutral  monobasic  salts  of  the  metals,  such 
as  chloride  of  sodium,  possess  only  a  low  degree  of  action,  or  are  wholly  inert. 
The  active  substances  are  also,  relatively,  most  efficient  in  small  proportions. 
The  chemical  action  must  be  different  on  the  substance  of  the  membrane,  at  its 
inner  and  outer  surfaces,  to  induce  osmose;  and  according  to  the  hypothetic  view, 
which  accords  best  with  the  phenomenon,  the  action  on  the  two  sides  is  not 
unequal  in  degree  only,  but  also  different  in  kind.  It  appears  as  an  alkaline 
action  on  the  albuminous  substance  of  the  membrane  at  the  inner  surface,  and 
as  an  acid  action  on  the  albumen  at  the  outer  surface. 

"  The  most  general  empirical  conclusion  that  can  be  drawn  is,  that  the  water 
always  accumulates  on  the  alkaline  or  basic  side  of  the  membrane.  H^ence,  with 
an  alkaline  salt — such  as  carbonate,  or  phosphate  of  soda — in  the  osmometer,  and 
water  outside,  the  flow  is  inwards ;  but  with  an  acid  in  the  osmometer,  on  the 
contrary,  the  flow  is  outwards,  or  there  is  negative  osmose,  the  liquid  then  falling 
in  the  tube." 

It  has  been  discovered  by  Matteucci  that  the  current  is  considerably  influenced 
by  the  direction  in  which  it  traverses  the  membrane;  if  this  be  composed  of  skin, 
the  movement  is  most  energetic  from  the  interior  to  the  exterior  surface,  thus 
corresponding  with  the  physiological  action  of  the  skin,  which  readily  exhales, 
but  does  not  so  readily  absorb.  In  the  mucous  membranes  the  action  was  found 
to  be  reversed,  —  that  is  from  the  exterior  to  the  interior;  this  movement  also  ac- 
cording with  the  physiological  action  of  these  membranes — absorption.  The  skin 
of  the  frog  appears  to  offer  an  exception  to  this  rule,  the  current  flowing  most 
readily  from  the  exterior  to  the  interior ;  but  it  ceases  to  be  an  exception  when 
it  is  remembered  that  the  function  of  the  skin  of  this  animal  is  not  to  exhale, 
but  to  absorb. 

The  absorption  which  takes  place  through  the  blood-vessels  of  the  intestinal 
canal  depends  upon  the  property  of  endosmose  which  has  been  thus  described 
Much  depends,  however,  upon  the  facility  with  which  the  substance  to  be  ab- 
sorbed can  penetrate  the  membrane  or  tissue  which  lies  between  it  and  the  blood- 
vessels; for  naturally  the  blood-vessels  are  not  bare  to  absorb.  Absorption 
through  membranes  is,  in  general,  inversely  to  the  thickness  of  their  epithelia, 
the  urinary  bladder  of  a  frog  being  traversed  in  less  than  a  second,  according  to 
Miiller;  and  the  absorption  of  poisons  by  the  stomach  or  lungs,  is  sometimes 
accomplished  in  an  immeasurably  short  time. 

The  substance  to  be  absorbed  must,  as  a  general  rule,  be  in  the  liquid  or  gaseous 
state,  or,  if  solid,  must  be  soluble  in  the  fluids  with  which  it  is  brought  in  con- 
tact. Solids  that  are  capable  of  very  fine  division  may  be  absorbed,  as,  for  in- 
stance, mercury  in  the  metallic  state  may  pass  into  and  remain  in  the  blood- 
vessels ;  and  finely-powdered  charcoal,  when  introduced  into  the  intestinal  canal, 
has  been  found  in  the  mesenteric  veins;  oil,  likewise,  when  reduced  to  a  fine 
emulsion,  will  pass  through  into  the  blood-vessels.1 

The  fuller  and  tenser  the  blood-vessels  of  a  part  are,  the  slower  and  more  diffi- 
cult will  be  the  absorption  of  fluids,  and  the  tension  may  be  so  great  as  to  prevent 
entirely  the  further  introduction  of  liquids ;  so  likewise  slowness  or  stagnation  of 
the  current  will  greatly  retard  the  absorbing  process,  both  of  which  conditions 
may  be  produced  by  the  application  of  suction  to  a  part,  as  is  frequently  done  in 
the  case  of  poisoned  wounds,  thus  preventing  the  absorption  of  a  virus  and  its 
transmission  through  the  system,  while,  on  the  other  hand,  a  rapid  capillary 
circulation,  or  a  less  tense  condition  of  vessels  will  greatly  facilitate  the 
introduction  of  liquids,  not  because  the  fluid  to  be  absorbed  is  more  quickly 
imbibed  into  the  tissues,  or  mingled  with  the  blood,  but  because  it  is  carried 

1  [For  a  fuller  exposition  of  this  subject,  see  article  "Eudosmose,"  in  the  Cyc.  of  Anat. 
and  Phys.,  the  article  Absorption  in  Prin.  of  Comp.  Phys.,  and  Kirkes  and  Paget,  Manual 
of  Physiology.] 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         139 

away  by  the  circulating  current  as  fast  as  it  is  introduced,  and  the  blood 
being  as  constantly  renewed,  is  as  constantly  fitted  for  the  reception  of  fresh  par- 
ticles.1—ED.] 

'["In  connection  with  the  subject  of  Endosmose,  some  interesting  experiments,  per- 
formed recently,  may  be  mentioned,1  showing  the  physical  influence  exerted  by  medicines  of 
various  kinds  upon  the  molecular  arrangement  of  chemical  substances  passing  through 
them. 

When  the  body  of  a  frog  was  exposed  to  a  strong  solution  of  chloride  of  calcium,  and 
then,  after  being  carefully  wiped,  to  a  solution  of  oxalate  of  ammonia,  there  were  found 
on  examining  the  blood  of  the  various  tissues  of  the  animal,  diverse  forms  of  the  precipi- 
tate of  oxalate  of  lime,  doubtless  owing  to  the  influence  exerted  by  the  animal  membrane. 
The  blood  from  the  heart  and  lungs,  the  appearance  of  which  is  thus  described  by  the 
author,  was  first  examined  under  the  microscope,  with  a  magnifying  power  of  210  diame- 
ters, which  displayed  innumerable  minute  cubical  particles,  floating  amongst  the  large 
elliptical  blood  corpuscles.  In  the  fibrous  tissue  between  the  epidermis  and  pectoralis 
major  muscle,  square  plates,  cubical  crystals,  and  parallelograms  were  seen,  together 
with  minute  particles,  the  largest  of  which  appeared  to  be  cubes. 

The  mesenteric  fold  of  the  peritonaeum  contained  the  same  equi-lateral,  equi-angular 
plates,  and  cubical  crystals.  In  the  fascia  of  the  thigh,  besides  numbers  of  these,  there 
appeared,  also,  beautiful  octohedral  crystals  of  the  oxalate  of  lime,  similar  in  all  respects 
to  those  formed  when  the  intestines  of  a  raccoon,  (Procyon  lotor,)  were  filled  with  a  solu- 
tion of  the  chloride  of  calcium,  and  immersed  in  a  solution  of  the  oxalate  of  ammonia. 

When  the  eggs  of  the  frog  were  mashed,  and  their  contents  spread  out  on  a  glass  slide 
and  examined  under  the  microscope,  they  contained  multitudes  of  equi-angular  plates,  and 
cubical  crystals  of  the  oxalate  of  lime. 

It  is  probable  that  the  exterior  fluids  passed  through  the  anus  and  cloaca  into  the  ovi- 
ducts and  ovaries,  and  finally  by  endosmose  into  the  eggs  themselves. 

In  the  fibrous  tissue  of  the  walls  of  the  abdomen,  in  addition  to  the  cubes  and  octohedra, 
and  equi-lateral  plates,  there  appeared,  also,  delicately  formed  dumb-bell  and  ellipsoidal 
crystals. 

When  the  plantar  fascia  of  the  foot  was  cut  through,  from  the  incision  flowed  a  fluid  re- 
sembling the  liquor  sanguinis  mixed  with  a  little  blood,  which,  under  a  magnifying  power 
of  210  diameters,  contained  beautiful  octohedral  and  dumb-bell  crystals  of  the  oxalate  of 
lime. 

This  experiment  was  repeated  with  slight  variations,  as  to  the  length  of  the  time,  and 
the  density  of  the  fluids,  and  in  every  instance,  without  any  exception,  the  results  were 
the  same. 

In  one  instance,  the  deposit  formed  within  the  blood  and  tissues  of  the  frog  assumed 
the  form  of  delicate  dumb-bell  and  cruciform  crystals  of  the  oxalate  of  lime.  In  another 
experiment  the  blood  from  the  ventricle  of  the  heart  contained  large  and  perfectly  formed 
octohedra,  with  a  few  dumb-bell  crystals,  while  the  various  tissues  and  muscles  contained 
chiefly  delicately  formed  dumb-bell  trystals,  and  the  aqueous  humor  of  the  eye  contained 
octohedral,  and  comparatively  large  acicular  crystals. 

We  see  then  by  these  microscopical  examinations,  that  the  oxalate  of  lime  assumed 
forms  different  in  all  respects  from  those  of  the  precipitate  thrown  down,  when  solutions 
of  the  chloride  of  calcium  and  oxalate  of  ammonia  are  brought  into  immediate  contact. 
The  precipitate  thus  formed  consists  of  minute  irregular  granules.  What  has  changed  it  ? 
It  has  been  accomplished,  without  doubt,  by  the  action  of  the  membranes  upon  the  chemical 
substances  in  solution  passing  through  them." 

The  influence  exerted  by  mucous  membranes  removed  from  all  vitality,  is  also  shown 
by  equally  interesting  experiments  by  the  same  observer ;  the  experiments  consisted  in 
filling  the  intestine  of  a  raccoon  (Procyon  lotor},  with  a  solution  of  chloride  of  calcium, 
whose  specific  gravity  was  1031,  and  immersing  it  in  a  solution  of  oxalate  of  ammonia, 
having  a  specific  gravity  1007.  In  the  course  of  an  hour  the  exterior  fluids  became 
cloudy,  with  a  white  precipitate,  the  oxalate  of  lime.  At  the  end  of  two  days,  a  copious 
white  deposit  had  settled  to  the  bottom  of  the  jar,  which,  under  a  magnifying  power  of 
210  diameters,  presented  the  appearance  of  innumerable  acicular,  rectangular,  and  irre- 
gular particles,  often  conglomerated  together  in  great  numbers,  forming  miniature  repre- 
sentations of  plants  with  their  branches  and  leaves. 

The  specific  gravity  of  exterior  fluid  had  fallen  to  1005. 

The  interior  fluid  was  next  examined,  the  intestine  having  been  punctured  and  its  con- 
tents carefully  removed.  Its  specific  gravity  had  changed  to  1003. 

1  [Abstract  of  experiments  upon  the  physical  influences  exerted  by  living,  organic,  and 
inorganic  membranes,  upon  chemical  substances  passing  through  them  by  endosmose,  bv 
Joseph  Jones,  Student  of  Medicine  in  the  University  of  Pennsylvania.  (Read  before  the 
Academy  of  Natural  Sciences,  Philadelphia,  October  25,  1854.)] 


140  OF    ABSORPTION    AND    SANGUIFICATION. 

122.  In  regard  to  the  degree  in  which  the  function  of  Nutritive  Absorption  is 
performed  by  the  Lacteals  and  by  the  Sanguiferous  system  respectively,  consider- 
able difference  of  opinion  has  prevailed.  When  the  Absorbent  vessels  were  first 

"  This  marked  change  of  its  specific  gravity  from  1031  to  1003,  shows  that  a  free  inter- 
change of  the  fluids  must  have  taken  place.  The  slight  change  in  the  exterior  fluid,  of 
1007  to  1005,  is  readily  explained,  when  we  consider  the  fact,  that  the  exterior  was  12, 
whilst  the  interior  was  only  4  fluid  ounces. 

Within  the  intestines  but  a  small  deposit  had  taken  place,  in  comparison  with  that  of 
the  exterior  fluid.  Under  the  microscope  this  presented  a  magnificent  crystalline  appear- 
ance, differing  wholly  from  that  of  the  exterior  fluids,  and  also  from  that  formed  when 
solutions  of  the  chlorides  of  calcium  and  oxalate  of  ammonia  are  brought  into  immediate 
contact. 

Amongst  the  crystals  there  were  no  less  than  seven  well  defined,  regularly  formed 
.varieties.  The  octohedral  and  dumb-bell  crystals  were  recognized  as  the  form  in  which  the 
oxalate  of  lime  almost  invariably  occurs  in  the  urine,  not  only  of  man,  but  also  of  other 
animals,  and  even  in  that  of  birds. 

Does  not  this  experiment  indicate  that  the  peculiar  forms  of  the  oxalate  of  lime,  occur- 
ring in  urine,  may  be  the  result  of  the  physical  action  of  the  basement  membrane  of  the 
tubuli  uriniferi  and  its  secretory  cells  ? 

The  tissues  of  the  intestine  were  next  examined. 

The  cellular  tissue  was  not  equally  injected ;  in  some  places  there  was  scarcely  any, 
while  in  others  there  was  a  very  abundant  deposit. 

In  all  places  the  mucous  membrane  appeared  free  from  any  deposit  of  the  oxalate  of 
lime.  It  was  not  easy,  however,  to  decide  this  question  by  the  microscope,  on  account 
of  the  difficulty  of  separating  completely  the  fibrous  tissue  in  which  occurred  a  copious 
crystalline  deposit. 

This  is  not  the  only  instance ;  out  of  numerous  examples,  the  following  are  selected : 

When  the  bladder  of  a  raccoon  (Procyon  lotor]  was  filled  with  a  solution  of  the  bi- 
chloride of  mercury,  and  immersed  in  a  solution  of  the  iodide  of  potassium,  a  brilliant  red 
crystalline  deposit  of  the  biniodide  of  mercury  took  place  upon  the  exterior,  whilst  upon 
the  interior  a  light  yellow  mass  of  lozenge-shaped  crystals  of  the  protiodide  of  mercury 
was  precipitated.  In  this  case  also  the  mucous  membrane  appeared  free  from  any  de- 
posit. 

When  the  intestines  of  a  raccoon  were  filled  with  a  solution  of  the  acetate  of  lead,  and 
immersed  in  a  solution  of  the  bichromate  of  potassa,  the  deposit  upon  the  exterior  con- 
sisted of  innumerable  small  irregular  granules,  while  that  upon  the  interior  consisted  of 
beautiful  stellate  crystals. 

When  a  sheep's  bladder  was  filled  with  a  solution  of  the  oxalate  of  ammonia,  and  im- 
mersed in  a  solution  of  the  chloride  of  calcium,  no  deposit  took  place  in  the  exterior  fluid, 
whilst  a  precipitate  of  the  oxalate  of  lime  fell  in  the  interior  fluid. 

Within  the  muscular  and  fibrous  coats  of  the  bladder  this  deposit  presented  the  same 
appearance.  The  fact  that  solutions  of  certain  chemical  substances  will  pass  through  a 
membrane  in  one  direction,  but  not  in  another,  was  illustrated  by  several  examples. 

The  stomach  of  a  raccoon  was  filled  with  a  solution  of  the  bichromate  of  potassa,  and 
immersed  in  a  solution  of  the  acetate  of  lead;  a  copious  deposit  of  the  chromate  of  lead 
took  place  in  the  exterior  fluid,  whilst  none  whatever  occurred  in  the  interior :  it  retained 
its  natural  color  and  appearance.  The  results  were  in  all  respects  the  same  when  the  in- 
testines of  this  animal  were  treated  in  a  similar  manner. 

When  the  stomach  was  treated  in  this  manner  a  deposit  took  place  only  upon  the  interior. 
When  the  oesophagus  of  a  large  rattlesnake  (Crotalus  adamanteus),  was  treated  in  a  similar 
way,  only  a  small  deposit  occurred  in  the  exterior  flu'id. 

The  stomach  of  a  raccoon,  and  a  portion  of  the  intestines  of  a  large  rattlesnake  were 
filled  with  a  solution  of  the  iodide  of  potassium,  and  immersed  in  a  solution  of  the  bi- 
chloride of  mercury ;  in  both  cases  a  copious  deposit  occurred  upon  the  exterior,  whilst 
little  or  no  precipitate  fell  in  the  interior  fluid. 

These  facts  are  due  to  one  of  two  causes.  Either  certain  chemical  substances  in  solu- 
tion exert  an  influence  upon  mucous  membranes,  changing  their  minute  anatomical  struc- 
ture, and  thus  destroying  their  power  of  carrying  on  the  physical  phenomena  of  endos- 
mose  and  exosmose ;  or  else  mucous  membranes  possess  a  power  of  choice,  as  it  were, 
dependent  upon  their  physical  constitution,  allowing  one  fluid  to  pass  through  in  one  direc- 
tion, but  not  another  fluid  holding  a  different  chemical  substance  in  solution,  in  an  oppo- 
site direction.  When  a  portion  of  the  small  intestine  of  a  sheep  was  filled  with  a  solution 
of  the  nitrate  of  lime  and  immersed  in  a  solution  of  the  oxalate  of  ammonia,  a  copious 
precipitate  of  the  oxalate  of  lime  took  place  in  the  exterior  fluid,  wjach  under  a  magnify- 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         141 

discovered,  and  their  functional  importance  was  perceived,  it  was  imagined  that 
the  introduction  of  alimentary  fluid  into  the  vascular  system  took  place  by  them 
alone.  Such  an  idea,  however,  would  be  altogether  inconsistent  with  the  facts 
of  Comparative  Anatomy  (See  PRINC.  OF  COMP.  PHYS.,  Chap,  iv.,  Am.  ed.) ; 
and  it  is  completely  negatived  by  the  results  of  experiment.  For  that  Absorp- 
tion is  effected,  to  a  very  considerable  amount,  by  the  agency  of  the  Blood- 
vessels, is  shown  in  the  first  place,  by  the  readiness  with  which  aqueous  fluids, 
and  even  alcohol,  are  taken-up  from  the  parietes  of  the  Stomach,  and  are  carried 
into  the  general  circulation.  Thus  in  a  case  of  extroversion  of  the  bladder,  ob- 
served by  Mr.  Erichsen,1  in  which  the  urinary  secretion  could  be  collected  imme- 
diately on  its  passing  from  the  kidney,  when  a  solution  of  ferrocyanide  of  potas- 
sium was  taken  into  the  stomach,  this  salt  was  detected  in  the  urine  in  one 
instance  within  1  minute,  and  in  three  other  instances  within  2?  minutes.  In 

ing  power  of  210  diameters  was  found  to  consist  of  innumerable  octohedral  crystals  of  dif- 
ferent sizes ;  also  a  few  dumb-bell  crystals. 

In  the  exterior  deposit  the  octohedra  were  about  one  hundred  times  more  numerous 
than  the  dumb-bell  crystals. 

In  the  interior  fluid  a  deposit  of  the  oxalate  of  lime  had  taken  place.  The  entire  de- 
posit consisted  of  innumerable  minute  and  delicately  formed  dumb-bell  crystals,  with  here 
and  there  an  octohedral  crystal.  In  the  interior  fluid,  unlike  the  exterior,  there  were  over 
a  hundred  dumb-bell  crystals  to  one  octohedral  crystal.  Minute  octohedra,  and  delicately 
formed  dumb-bells,  were  found  within  the  meshes  of  the  fibrous  tissue.  By  comparing 
this  experiment  with  the  former  ones  in  which  solutions  of  the  same  chemical  substances 
were  used,  we  are  forcibly  taught  the  following  laws : 

1st.  Mucous  membranes  from  the  same  relative  part  of  the  bodies  of  different  animals, 
exert  different  physical  influences  upon  the  same  chemical  substances. 

2d.  Mucous  membranes  from  the  same  animal,  but  from  different  parts  of  the  body, 
exert  different  physical  effects  upon  solutions  of  the  same  chemical  substances. 

3d.  The  physical  influence  exerted  by  the  membrane  is  not  the  same  in  endosmose  and 
exosmose ;  it  differs  with  the  direction  of  the  current. 

A  very  important  question  now  presents  itself  for  consideration.  May  not  this  change 
of  form  in  the  precipitates  be  due  to  the  presence  of  some  animal  substance  or  fluid, 
as  fibrin,  blood,  albumen,  or  serum,  and  not  to  the  physical  action  of  the  membranes.  To 
determine  this  point  a  series  of  careful  experiments  were  instituted  with  the  following 
substances :  albumen,  fibrin,  yolk  of  hen's  egg,  warm  blood,  cold  blood,  puti-escent  blood, 
warm  serum,  cold  serum,  putrescent  serum,  and  urine.  In  no  case  did  the  presence  of 
these  substances  produce  a  crystalline  deposit  of  the  oxalate  of  lime.  Each  experiment 
was  performed  in  several  different  ways,  and  under  different  circumstances ;  sometimes 
the  densities  of  the  solutions  of  the  chloride  of  calcium  and  oxalate  of  ammonia  were 
varied,  at  others  the  temperature  and  conditions  of  the  foreign  body.  But  one  result  at- 
tended all  these  experiments — no  crystalline  deposit.  In  many  instances  the  interior  and 
exterior  fluids  were  mingled,  in  both  of  which  crystals  had  been  produced  by  the  action 
of  the  membrane,  and  in  every  case  the  precipitate  of  the  oxalate  of  lime  thrown  down 
consisted  of  irregular  granules  without  any  crystalline  form  whatever.  Does  not  this 
prove  conclusively  that  the  simple  presence  of  the  different  membranes  did  not  cause  the 
change  of  the  physical  form  of  the  precipitate  ? 

The  next  question  which  presented  itself  was,  whether  dry  membranes  exert  a  physical 
influence  upon  substances  passing  in  solution  through  them,  capable  of  changing  their 
physical  forms  ?  To  determine  this  point  several  experiments  were  performed  with  dry 
membranes,  with  solutions  of  the  chloride  of  calcium  and  oxalate  of  ammonia,  varying 
the  relative  positions  and  densities  of  the  fluids  in  each  experiment.  In  no  instance  was 
a  regular  crystalline  deposit  obtained.  In  only  one  experiment,  two  or  three  octohedral 
crystals  occurred  in  the  midst  of  millions  of  irregular  particles. 

All  the  experiments,  thus  far,  prove  that  dry  membranes  exert  little  or  no  physical  in- 
fluence upon  chemical  substances  in  solution  parsing  through  them. 

The  next  object  was  to  ascertain  the  influence  of  inorganic  septa,  during  the  endosmotic 
action.  In  these  experiments  thin  vessels  of  baked  clay  were  used.  These  were  filled 
with  a  solution  of  the  chloride  of  calcium  and  immersed  in  a  glass  jar  containing  a  solu- 
tion of  the  oxalate  of  ammonia.  The  relative  positions  and  densities  of  these  fluids  were 
also  changed.  In  no  instance  was  a  regular  crystalline  deposit  obtained.  So  far  then  aa 
these  experiments  go,  it  may  be  asserted,  that  inorganic  septa  do  not  exert  a  physical  in- 
fluence upon  chemical  substances  passing  through  them,  capable  of  changing  the  arrange- 
ment of  their  molecules." — ED.] 

1  "Medical  Gazette,*  vol.  xxxvi.  p.  363. 


142  OP    ABSORPTION    AND    SANGUIFICATION. 

all  these  cases,  however,  the  stomach  may  be  presumed  to  have  been  empty,  and 
the  vascular  system  in  a  state  of  aptitude  for  absorption ;  since  the  experiments 
were  made  either  after  a  long  fast,  or  at  least  four  hours  after  a  light  meal. 
When,  on  the  other  hand,  the  salt  was  introduced  into  the  stomach  soon  after  the 
ingestion  of  alimentary  substances,  a  much  longer  period  elapsed  before  it  could 
be  detected  in  the  urine ;  thus,  when  a  substantial  meal  had  been  taken  two  hours 
previously,  the  interval  was  12  minutes ;  when  tea  and  bread-and-butter  had  been 
taken  one  hour  previously,  the  interval  was  14  minutes;  a  similar  meal  having 
been  taken  twenty-four  minutes  previously,  the  interval  was  16  minutes ;  when 
only  two  minutes  had  passed  since  the  conclusion  of  such  a  meal,  the  interval 
was  27  minutes;  and  when  a  solid  meal  had  been  concluded  just  before  the 
introduction  of  the  salt,  the  interval  was  39  minutes.1  —  These  facts  are  of 
great  importance,  in  showing  the  very  marked  influence  which  the  state  of 
the  stomach  exercises  upon  the  absorption  of  matters  introduced  into  it.  Not 
less  important,  however,  is  the  state  of  the  vascular  system  in  regard  to  tur- 
gescence  or  emptiness;  for  it  was  found  by  Magendie,  that  when  he  had  in- 
jected a  considerable  quantity  of  water  into  the  veins  of  a  dog,  poison  was 
absorbed  very  slowly;  whilst  if  he  relieved  the  distension  by  bleeding,  there 
was  speedy  evidence  of  its  entrance  into  the  circulation. —  The  rapidity  with 
which  not  only  aqueous  but  alcoholic  liquids  introduced  into  the  stomach  may 
pass  into  the  general  circulation,  has  been  shown  by  the  experiments  of  Dr. 
Percy;2  who  found  that  when  strong  alcohol  was  injected  into  the  stomach 
of  dogs,  the  animals  would  sometimes  fall  insensible  to  the  ground  immedi- 
ately upon  the  completion  of  the  injection,  their  respiratory  and  cardiac  move- 
ments ceasing  within  two  minutes ;  and  that  on  post-mortem  examination  in 
such  cases,  the  stomach  was  nearly  empty,  whilst  the  blood  was  highly  charged 
with  alcohol;  thus  rendering  it  almost  certain,  that  not  merely  the  final  destruc- 
tion of  nervous  power,  but  the  immediate  loss  of  sensibility,  was  due  to  the  action 
of  alcoholized  blood  upon  the  nervous  centres. —  Finally,  numerous  experiments 
have  been  made  by  various  physiologists,  which  have  demonstrated  that  absorp- 
tion of  alimentary  and  other  substances  may  take  place  from  the  walls  of  the 
Stomach ;  these  substances  having  been  prevented  from  passing  into  the  intestine, 
by  a  ligature  around  the  pylorus.  Now  as  the  Absorbent  system  does  not  present 
that  peculiar  arrangement  in  the  coats  of  the  stomach,  which  it  does  in  those  of 
the  intestinal  tube,  there  can  be  little  doubt  that  the  introduction  of  such  sub- 

1  The  great  rapidity  with  which  soluble  salts,  introduced  into  the  stomach,  make  their 
appearence  in  the  urine,  has  led  M.  Cl.  Bernard  to  think  that  some  more  direct  channel 
must  exist  for  their  passage  from  the  stomach  to  the  kidneys,  than  that  which  the  ordinary 
current  of  the  sanguiferous  circulation  affords ;  and  to  advance  the  extraordinary  doctrine, 
that  whilst  absorption  is  going-on,  there  is  a  constriction  of  the  vena  cava  above  the 
entrance  of  the  hepatic  vein,  whereby  a  reflux  of  the  blood  discharged  by  it  takes  place, 
so  that  it  passes  into  the  renal  vein,  without  reaching  the  heart.  He  asserts  that  a  pecu- 
liar thickening  of  the  muscular  coat  exists  in  the  upper  part  of  the  vena  cava,  whereby  its 
contraction  is  occasioned;  also  that  there  are  (in  the  horse  at  least)  direct  passages  by 
which  a  part  of  the  portal  blood  may  be  discharged  into  the  vena  cava,  without  passing 
through  the  liver.  ("  L' Union  Medicale,"  1849,  No.  115.)  —  Now,  in  the  first  place,  this 
hypothesis  is  not  necessary  to  explain  the  facts ;  for,  as  is  shown  above,  there  is  evidence 
of  the  transmission  of  substances  to  other  parts,  with  at  least  as  much  rapidity  as  is  indi- 
cated by  their  appearance  in  the  urine.  And,  in  the  second  place,  if  the  supposed  reflux 
really  took  place,  it  must  affect  the  whole  venous  circulation  of  the  trunk  and  lower  extre- 
mities, except  such  as  the  vena  azygos  and  a  few  other  small  channels  could  provide-for ; 
and  must  occasion  (to  make  good  the  conditions  of  the  problem)  not  merely  a  stagnation, 
but  an  absolute  reflux,  so  that  the  veins  would  be  metamorphosed  into  arteries,  and  the 
arteries  into  veins.  How  the  vis  d  tergo,  originally  derived  from  the  heart,  can  thus  be 
strong  enough  at  the  very  end  of  the  systemic  circulation,  not  merely  to  neutralize,  but 
actually  to  overcome,  the  force  which  it  exercises  almost  close  to  the  heart,  M.  Bernard 
has  not  informed  us. 

a  "  Experimental  Enquiry  concerning  the  Presence  of  Alcohol  in  the  Ventricles  of  the 
Brain,"  p.  61. 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         143 

stances  into  the  system  must  be  effected  chiefly,  if  not  entirely,  through  the  me- 
dium of  its  sanguiferous  capillaries. 

123.  That  the  Blood-vessels  of  the  Intestinal  tube,  also,  largely  participate  in 
the  introduction  of  soluble  alimentary  matter  into  the  system,  has  been  clearly 
proved  by  various  observations  upon  the  constitution  of  the  blood  of  the  Mesen- 
teric  veins  (§  183);  these  having  shown,  that  after  the  digestion  of  albuminous 
and  farinaceous  or  saccharine  substances,  albuminose,  dextrin,  grape-sugar,  and 
lactic  acid  are  detectible  in  that  fluid,  whose  usual  composition  is  greatly  altered 
by  the  presence  of  these  substances,  as  well  as  by  the  augmented  proportion  of  water 
which  it  contains.  Moreover  it  is  asserted  by  Bruch1  that  so  large  a  quantity  of 
fat  is  absorbed  into  the  blood-vessels,  that  the  superficial  capillary  network  some- 
times presents  an  opalescent  whiteness  j  and  this  fact  is  in  harmony  with  the 
result  experimentally  obtained  by  Matteucci,2  who  found  that  a  weak  alkaline 
liquid  will  draw  to  itself,  through  a  thin  membranous  septum,  oleaginous  parti- 
cles diffused  in  a  state  of  fine  division  through  a  liquid  on  the  other  side.  We 
may  consider  the  Sanguiferous  vessels,  then,  as  affording  the  usual  channel  by 
which  a  large  part  of  the  nutritive  materials  are  introduced  into  the  system ; 
but  these  are  not  allowed  to  pass  into  the  general  current  of  the  circulation, 
until  they  have  been  subjected  to  an  important  assimilating  process,  which  it 
appears  to  be  one  great  office  of  the  Liver  to  perform,  whereby  they  are  rendered 
more  fit  for  the  purposes  they  are  destined  to  serve  in  the  economy.  Of  this  we 
shall  presently  have  to  speak  (§  132).  —  But  the  absorbent  power  which  the 
blood-vessels  of  the  Alimentary  canal  possess,  is  not  limited  to  alimentary  sub- 
stances ;  for  it  is  through  them  almost  exclusively,  that  soluble  matters  of  every 
other  description  are  received  into  the  circulation.  This,  which  may  now  be  con- 
sidered a  well-established  fact,  was  first  clearly  shown  by  the  carefully-conducted 
experiments  of  MM.  Tiedemann  and  Gmelin,3  who  mingled  with  the  food  of  ani- 
mals various  substances,  which,  by  their  colour,  odour,  or  chemical  properties, 
might  be  easily  detected  in  the  fluids  of  the  body :  after  some  time  the  animal 
was  examined  ]  and  the  result  was,  that  unequivocal  traces  of  such  substances 
were  not  unfrequently  detected  in  the  venous  blood  and  in  the  urine,  whilst  it 
was  only  in  a  very  few  instances  that  any  indication  of  them  could  be  discovered 
in  the  chyle.  The  colouring  matters  employed  were  various  vegetable  substances ; 
such  as  gamboge,  madder,  and  rhubarb ;  the  odorous  substances  were  camphor, 
nmsk,  assafcetida,  &c. ;  while,  in  other  cases,  various  saline  bodies,  such  as  chlo- 
ride of  barium,  acetate  of  lead  and  of  mercury,  and  some  of  the  prussiates,  which 
might  easily  be  detected  by  chemical  tests,  were  mixed  with  the  food.  The 
colouring  matters,  for  the  most  part,  were  carried  out  of  the  system,  without  being 
received  either  into  the  veins  or  the  lacteals ;  the  odorous  substances  were  gene- 
rally detected  in  the  venous  blood  and  in  the  urine,  but  not  in  the  chyle ;  whilst 
of  the  saline  substances,  many  were  found  in  the  blood  and  the  urine,  and  a  very 
few  only  in  the  chyle.  A  similar  conclusion  might  be  drawn  from  the  numerous 
instances,  in  which  various  substances  introduced  into  the  intestines  have  been 
detected  in  the  blood,  although  the  thoracic  duct  had  been  tied;  but  these  results 
are  less  satisfactory,  because,  though  there  is  probably  no  direct  communication 
(as  maintained  by  many)  between  the  lacteals  and  the  veins  in  the  mesenteric 
glands,  the  partitions  which  separate  their  respective  contents  are  evidently  so 
thin,  that  transudation  may  readily  take  place  through  them.  [4It  is  stated  by 
Lehmann  that  the  substances  which  undergo  no  essential  change  in  the  intestinal 

1  "  Siebold  and  Kolliker's  Zeitschrift,"  April,  1853. 

1  See  his  "  Lectures  on  the  Physical  Phenomena  of  Living  Beings,"  Pereira's  edition, 
p.  111. 

8  "Versuche  uber  die  Wege  auf  welch  en  Substanzen  aus  dem  Magen  und  Darmkanal  ins 
Blut  gelangen,"  Heidelberg,  1820. 

4  Brit,  and  For.  Med.-Chir.  Rev.,  Jan.  1855,  containing  a  review  of  Lehmann's  Compen- 
dium of  Physiological  Chemistry,  and  of  a  Manual  of  Physiological  Chemistry  by  the 
same  author 


144  OF    ABSORPTION    AND    SANGUIFICATION. 

canal  from  the  action  of  the  digestive  fluids,  are  particularly  adapted  for  imme- 
diate absorption  by  the  blood-vessels,  yet  it  is  not  clearly  ascertained  what  relation 
exists  between  these  two  qualities.  It  is  not  the  saline  nature  alone  which  makes 
the  alkaline  salts  so  easy  of  absorption,  for  many  other  salts  are  not  taken  up  by 
the  capillary  blood-vessels;  and,  on  the  other  hand,  urea,  alcohol,  and  certain 
poisons,  pass  as  easily,  and  perhaps  more  quickly,  into  the  fluids  of  the  body  than 
many  of  those  salts;  neither  is  it  merely  the  degree  of  solubility  of  a  substance, 
but  it  is  the  union  of  many  qualities,  which  confers  both  a  capability  of  being 
absorbed,  and  a  power  of  resisting  the  action  of  the  digestive  fluids.  Since  there 
are  many  poisons  which  the  system  quickly  takes  up  from  the  intestinal  canal, 
and  others  which  are  not  so  absorbed,  we  cannot  expect  to  find  the  reason  of  these 
facts  in  an  instinct  of  the  absorbent  organ,  but  in  definite,  fundamental  principles 
of  the  substances. 

The  following  substances,  according  to  Lehmann,  reach  the  circulation,  not 
through  the  lymphatics,  but  directly  through  the  capillary  blood-vessels  : — all  the 
neutral  salts  of  the  alkalies,  the  acids  of  which  have  not  a  greater  affinity  for 
ether  bodies  to  be  met  with  in  the  intestinal  contents;  among  these  are  the 
chlorides  of  sodium  and  potassium,  the  iodides  and  bromides  of  potassium;  the 
phosphates,  sulphates,  chlorates,  nitrates,  borates,  and  arseniates  of  the  alka- 
lies ;  yellow  ferro-cyanide  of  potassium ;  the  compound  of  rhodium  and  potassium 
(Rhodanltalium) ;  and  the  compounds  of  alkalies,  with  such  organic  acids  as  do 
not  contain  nitrogen.  A  second  group  of  bodies,  which  are  chiefly  absorbed  by 
the  intestinal  capillaries,  are  the  acids,  both  mineral  and  organic.  A  third  group 
contains  alcohol,  ether,  wood-spirit,  fusel  oil.1  A  fourth,  several  volatile  oils,  both 
free  from  oxygen,  and  containing  oxygen  and  sulphur  (camphor,  oil  of  radishes, 
oil  of  assaftetida,  &c.) ;  to  this  class  belong  also  the  empyreumatic  and  natural 
odoriferous  matters,  as  musk,  and  the  constituents  of  the  animal  oil  of  Dippel, 
&c.  A  fifth,  several  alkaloids,  both  fixed  and  volatile,  for  example,  strychnia, 
brucia,  morphia,  thein,  nicotin.  Lastly,  some  pigments  should  be  enumerated, 
which  are  not  to  be  found  in  the  chyle,  but  in  the  urine;  for  example,  the 
colouring  matters  of  alkanet,  gamboge,  bilberries,  black  cherries,  rhubarb,  log- 
wood, madder,  litmus,  cochineal,  sap  green,  and  tincture  of  indigo. 

In  so  great  a  variety  as  is  presented  by  the  substances  above  enumerated,  it 
would  be  difficult,  if  not  impossible,  to  find  a  common  aggregate  of  properties  to 
which  their  capability  of  absorption  through  the  blood-vessels  might  be  referred ; 
but  certain  other  bodies,  which  far  exceed  them  in  solubility,  for  example,  do  not, 
in  direct  experiments,  show  the  least  tendency  to  pass  into  the  blood  through  the 
capillaries,  while  they  are  very  easily  taken  up  by  the  lymphatics,  or,  notwith- 
standing their  great  solubility,  traverse  the  entire  intestinal  tract  unabsorbed; 
thus  gum,  the  colouring  matter  of  turmeric,  &c.,  which  are  extremely  soluble, 
are  neither  taken  up  from  the  intestines  by  the  blood-vessels  nor  by  the  lym- 
phatics. The  curara  poison,  which  is  probably  identical  with  the  wourali,  and 
the  poison  of  serpents,  appear  to  belong  to  the  latter  class  of  bodies ;  we  might 
think  this  a  wise  provision  of  nature,  were  it  not  that  gum  and  turmeric  pigment, 
which  are  comparatively  harmless,  are  denied  access  to  the  chyle  and  capillaries 
equally  with  the  poison  of  serpents,  which  seldom  reaches  the  stomach  :  while  no 
obstacle  exists  to  the  absorption  of  other  poisons  which  are  seldom  received  in 
wounds,  but  usually  reach  the  intestine.  It  is  clear  that  only  soluble  matters  are 
capable  of  absorption,  but  the  solubility  of  those  quoted  above  is  so  variable  that 
we  cannot,  by  it  alone,  explain  their  capability  of  being  absorbed  by  the  capillary 
blood-vessels.  The  diffusibility  of  most  of  the  substances,  and  their  endosmotic 
squivalent,  which  is  incontestably  connected  with  it,  have  as  yet  unfortunately 
been  too  little  investigated  to  refer  their  facility  of  absorption  to  these  principles ; 
but  it  is  probable  that  this  facility  depends  on  their  diffusibility,  their  volatility, 
and  a  certain  simplicity  of  composition,  approaching  to  a  binary  constitution ; 
accordingly,  those  soluble  matters  which  belong  to  none  of  the  above  groups,  as 
1  Schlossberger :  Arch,  fur  Physiol.  Med.,  Band  ix.  §  267—269. 


ABSORPTION    FROM    THE    DIGESTIVE    CAVITY.         145 

albumen,  emulsion,  gum,  and  even  sugar,  have  resisted  all  the  attempts  of  che- 
mists to  account  for  their  composition  by  reference  to  the  usual  laws  of  chemical 
affinity  or  polarity. 

The  substances  enumerated  do  not,  properly  speaking,  become  the  objects 
of  digestion,  as  they  pass  into  the  circulation  from  the  intestinal  canal,  in 
the  same  state  in  which  they  reached  the  latter.  The  compounds  which  some 
of  them  form  within  the  body  with  acids,  need  scarcely  be  mentioned,  as  the  acids 
do  not  effect  any  essential  change  in  them. 

In  opposition  to  the  opinion  above  expressed,  that  wourali  is  not  absorbed  from 
the  intestinal  canal,  are  the  statements  of  Dr.  Braiuard,  that  the  poison  may  be  ad- 
ministered to  an  animal  and  allowed  to  remain  in  its  intestinal  canal  for  twenty- 
four  hours,  at  the  end  of  which  time  the  stomach  and  intestinal  canal  will  be 
found  empty,  and  on  washing  them  carefully  the  fluid  used  may  be  injected  into 
the  veins  of  another  without  effect. 

Another  circumstance  stated  by  Lehmann  is,  "that  notwithstanding  its  solu- 
bility, the  reception  of  gum  into  the  animal  organism  is  still  doubtful.  Though 
it  seldom  occurs  in  the  food  even  of  herbivorous  animals,  its  frequent  therapeutic 
employment,  and  its  pecular  chemical  and  physiological  behaviour,  demand  atten- 
tion. The  results  of  experiment  make  it  highly  improbable  that  even  a  small 
portion  of  gum  is  changed  in  digestion  into  sugar.  All  attempts  to  discover  it  in 
the  chyle,  blood,  or  urine  have  failed;  but  it  is  largely  found  in  the  excrements 
of  animals  fed  on  it: — thus,  of  50  grains  given  to  a  duck,  46  were  recovered  from 
the  excrement  passed  in  the  course  of  nine  hours.  From  these  and  other  experi- 
ments, it  is  evident  that  if  this  substance  be  at  all  capable  of  being  absorbed,  it  is 
only  very  slowly,  and  in  very  small  quantity,  that  it  can  pass  into  the  circulation.1 

Has  anything  been  ascertained  as  to  the  diffusion  or  transudation  of  gum, 
which  may  account  for  the  foregoing  facts  ?  According  to  Graham,  its  diffusi- 
bility  is  one-half  less  than  that  of  sugar  from  starch,  and  four  or  five  times  less 
than  that  of  chloride  of  sodium,  but  four  times  higher  than  that  of  albumen. 
Jolly  found  the  endosmotic  equivalent  of  gum  to  be  much  greater  than  that  of 
sugar.  The  simplest  endosmotic  experiment  will  prove  that  animal  membrane  is 
not  impermeable  to  gum ;  it  remains  to  show  what  the  mechanical  conditions  are 
which  allow  the  passage  of  but  so  very  little  gum  from  the  digestive  tube  into  the 
blood.  In  a  word,  much  remains  to  be  done  before  we  can  pronounce  a  decided 
opinion  on  the  behaviour  of  this  substance  in  the  intestinal  canal,  or  venture  to 
assume  the  interference  of  vital  powers  in  resisting  its  absorption.  The  use  of 
mucilaginous  mixtures  in  acute  diseases,  if  any,  is  evidently  only  negative." 2 — ED.] 

124.  This  Absorption  by  the  Blood-vessels  is  a  simple  physical  operation,  de- 
pending upon  the  relative  consistency  and  miscibility  of  the  blood  and  of  the 
liquid?  to  be  absorbed,  and  upon  the  rapid  movement  of  the  blood  through  the 
vessels.  Where  the  contents  of  the  alimentary  canal  are  of  less  specific  gravity 
than  the  blood,  and  are  capable  of  readily  mingling  with  it,  an  endosmotic  current 
will  be  established,  through  the  delicate  parietes  of  the  blood-vessels  and  their 
thin  investments,  between  the  two  liquids,  the  former  passing  towards  the  other; 
mid  in  this  mode,  albuminous,  gelatinous,  saccharine,  saline,  and  other  soluble 
substances  may  be  caused  to  enter  the  blood,  if  their  solution  be  not  too  concen- 
trated. But  if  their  density  be  equal  to  that  of  the  blood,  or  nearly  so,  little  or 
no  absorption  is  likely  to  take  place ;  and  one  purpose  which  is  answered  by  the 
very  copious  discharge  of  aqueous  fluid  into  the  alimentary  canal,  during  the 

1  This  is  at  variance  with  certain  facts  which  appear  well  authenticated.  The  late  Dr. 
Pereira  quotes  an  instance  in  which  a  thousand  persons  supported  themselves  for  two 
months  on  the  gum  which  they  were  carrying  as  merchandise;  and  six  or  eight  ounces  for 
an  adult  are  said  to  be  sufficient  to  sustain  life.  Elements  of  Materia  Medica  and  Thera- 
peutics, by  Jonathan  Pereira,  M.  D.,  1st  Am.  Ed.,  1843'  p.  78. 

''  [The  reader  is  referred  to  the  whole  of  the  review,  from  which  the  above  is  quoted, 
for  a  fuller  exposition  of  the  subject  — ED.] 

10 


116  OF     ABSORPTION    AND    SANGUIFICATION. 

operation  of  digestion,  is  obviously  the  reduction  of  the  density  of  the  solution 
to  a  favourable  point.  If,  again,  the  density  of  the  contents  of  the  alimentary 
canal  should  exceed  that  of  the  blood,  an  endosraotic  current  might  perhaps  be 
established  in  the  opposite  direction ;  but  their  dilution  would  probably  be  effected 
so  speedily,  that  little  of  the  contents  of  the  blood-vessels  would  be  thus  drawri- 
forth,  more  especially  as  animal  membranes  appear  to  have  a  special  power  of 
resisting  the  passage  of  Albumen,  whilst  they  give  free  transmission  to  Albumi- 
nose.1  —  That  the  movement  of  blood  in  the  vessels  will  vastly  increase  the  rate 
of  endosmotic  absorption,  is  easily  proved  experimentally ;  and  this  it  is,  which 
constitutes  the  main  difference  between  the  living  and  the  dead  subject.2 

125.  It  is  a  very  remarkable  fact,  which  has  recently  been  fully  substantiated, 
that  not  merely  soluble  matters,  but  insoluble  substances  in  a  state  of  minute 
division,  may  find  their  way  from  the  alimentary  canal  into  the  current  of  the 
circulation.      Thus  it  was  found  by  Oesterlen3  that  particles  of  finely-divided 
charcoal,  introduced  into  the  alimentary  canal,  could  be  distinguished  in  the 
blood  of  the  mesenteric  veins ;  and  similar  results  have  been  obtained  by  Eber- 
hard,  and  by  Mensonides  and  Bonders,  not  only  with  charcoal,  but  also  with  sulphur 
and  even  with  starch,  the  latter  substance  being  at  once  detectible  in  the  blood  by 
the  iodine-test.     It  is  doubtful  whether  these  particles  are  taken-up  by  the  lacteal 
system;  though  Donders  seems  of  opinion,  from  finding  them  deposited  in  the 
lungs  rather  than  in  the  liver,  that  the  former  is  their  more  usual  channel  of 
entrance.4     How  they  find  their  way  through   the  walls  of  the  vessels,  is  at 
present  a  complete  mystery. 

2. — Absorption  from  the  body  in  general 

126.  The  Mucous  Membrane  of  the  alimentary  canal  is  by  no  means  the  only 
channel  through  which  nutritive  or  other  substances  may  be  introduced  into  the 
circulating  apparatus  from  external  sources.     The  Lymphatic  system  is  present 
in  all  animals  which  have  a  lacteal  system ;  and  the  two,  as  already  pointed-out, 
evidently  constitute  one  set  of  vessels.     The  Lymphatics,  however,  instead  of 
commencing  on  the  intestinal  walls,  are  distributed  through  most  of  the  vascular 
tissues  of    the  body,  and  especially  in  the  Skin;   but  their  number   bears  no 
proportion  whatever  to  the  vascularity  of  the  several  tissues,  or  to  the  amount  of 
interstitial  change  which  these  undergo ;  and  it  is  remarkable  that  the  Nervous 
centres  should  be  (so  far  as  is  yet  known)  entirely  destitute  of  them,  and  that 
they  should  be  so  scanty  in  the  interior  of  Muscles,  as  to  suggest  that  they  belong 
rather  to  the  connective  areolar  tissue  than  to  the  muscular  substance  itself. 
Their  origins  cannot  be  clearly  traced ;  but  they  seem  in  general  to  form  a  plexus 
in  the  substance  of  the  tissues,  from  which  the  convergent  trunks  arise.     After 
passing,  like  the  lacteals,  through  a  series  of  glandular  bodies  (the  precise  nature 
of  which  will  be  presently  considered,  §  133,)  they  empty  their  contents  into  the 
same  receptacle  with  the  lacteals ;  and  the  mingled  products  of  both  pass  into 
the  Sanguiferous  system.     We  find  in  the  Skin,  also,  a  most  copious  distribution 
of  capillary  blood-vessels,  the  arrangement  of  which  is  by  no  means  unlike  that 

1  It  is  considered  by  Liebig  that  the  purgative  effects  of  concentrated  saline  solutions 
are  to  be  accounted-for  on  this  principle,  —  the  establishment  of  an  endosmotic  current 
from  instead  of  towards  the  circulating  system.  It  is  difficult,  however,  thus  to  account 
for  all  the  phenomena  of  saline  purgation ;  and  the  Author  greatly  doubts  the  validity  of 
the  explanation. —  It  may,  however,  be  applied  with  more  probability,  to  the  fact  of  which 
the  Author  was  assured  by  the  late  Dr.  Prout;  viz.,  that  having  fed  a  dog  upon  pure 
starch,  he  had  found  albumen  in  the  duodenum.  On  this  fact  Dr.  Prout  much  relied  as  a 
proof  of  the  convertibility  of  starch  into  albumen, — an  idea  which  would  now  be  universally 
condemned  by  Organic  Chemists;  but  it  does  not  seem  difficult  to  believe,  that  the  presence 
of  a  viscid  mass  of  half-digested  starch  might  have  determined  a  transudation  of  albumen 
from  the  blood-vessels  by  endosmosis. 

*  On  the  whole  of  this  subject,  see  the  Author's  "  Princ.  of  Comp.  Phys.,"  CHAP.  iv. 

§  "  Heller's  Archiv.,"  1847.  4  "  Henle"'s  Zeitschrift,"  1851. 


ABSORPTION    FROM    THE    BODY    IN    GENERAL.         147 

of  the  blood-vessels  of  the  alimentary  canal ;  and  its  surface  is  further  extended 
by  the  elevations  that  form  the  sensory  papillae,  which  are  in  many  points 
comparable  to  the  intestinal  villi,  although  their  special  function  is  so  different. 

127.  In  the  lowest  tribes  of  animals,  and  in  the  earliest  condition  of  the  higher, 
it  would  seem  as  if  the  Absorption  by  the  external  surface  is  almost  equally 
important  to  the  maintenance  of  life,  with  that  which  takes  place  through  the 
internal  reflexion  of  it  forming  the  walls  of  the  Digestive  cavity.     In  the  adult 
condition  of  most  of  the  higher  animals,  however,  the  special  function  of  the 
latter  is  so  much  exalted  as  usually  to  supersede  the  necessity  of  any  other  supply; 
and  the  function  of  the  cutaneous  and  pulmonary  surfaces  may  be  considered  as 
rather  that  of  exhalation,  than  of  absorption.1     But  there  are  peculiar  conditions 
of  the  system,  in  which  the  imbibition  of  fluid  through  these  surfaces  is  per- 
formed with  great  activity,  supplying  what  would  otherwise  be  a  most  important 
deficiency.     It  may  take  place  either  through  the  direct  application  of  fluid  to 
the  surface,  or  even  through  the  medium  of  the  atmosphere,  in  which  a  greater 
or  less  proportion  of  watery  vapour  is  usually  dissolved.     The  absorption  occurs 
most  vigorously,  when  the  system  has  been  drained  of  its  fluid,  either  by  an 
excess  of  the  excretions,  or  by  a  diminution  of  the  regular  supply. 

128.  It  may  be  desirable  to  adduce  some  individual  cases,  which  will  set  this 
function  in  a  striking  point  of  view ;   and  those  may  be  first  noticed,  in  which 
the  Absorption  took  place  through  the  contact  of  liquids  with  the  skin.     It  is 
well  known  that  shipwrecked  sailors,  and  others  who  are  suffering  from  thirst, 
owing  to  the  want  of  fresh  water,  find  it  greatly  alleviated,  or  altogether  relieved, 
by  dipping  their  clothes  into  the  sea  and  putting  them  on  whilst  still  wet,  or  by 
frequently  immersing  their  own  bodies.2 — In  a  case  related  by  Dr.  Currie,  of  a 
patient  laboring  under  dysphagia  in  its  most  advanced  stage,  (the  introduction  of 
any  nutriment,  whether  solid  or  fluid,  into  the  stomach,  having  become  perfectly 
impracticable,)  an  attempt  was  made  to  prolong  his  existence,  by  the  exhibition 
of  nutritive  enemata,  and  by  immersion  of  the  body,  night  and  morning,  in  a 
bath  of  milk  and  water.     During  the  continuance  of  this  plan,  his  weight,  which 
had  previously  been    rapidly  diminishing,  remained   stationary,  although   the 
quantity  of  excretion  was  increased.     How  much  of  the  absorption,  which  must 
have  been  effected  to  replace  the  amount  of  excreted  fluid,  is  to  be  attributed  to 
the  baths,  and  how  much  to  the  enemata,  it  is  not  easy  to  say ;  but  it  is  important 
to  remark  that  "the  thirst,  which  was  troublesome  during  the  first  days  of  the 
patient's  abstinence,  was  abated,  and,  as  he  declared,  removed,  by  the  tepid  bath, 
in  which  he  had  the  most  grateful  sensations."     "It  cannot  be  doubted/'  Dr. 
Currie  observes,   "that  the  discharge  by  stool  and  perspiration  exceeded   the 
weight  of  the  clysters ;"  and  the  loss  by  the  urinary  excretion,  which  increased 
from  24  oz.  to  36  oz.  under  this  system,  is  only  to  be  accounted  for  by  the  cuta- 
neous absorption.3 — Dr.  S.  Smith  mentions  that  a  man,  who  had  lost  nearly  3  Ibs. 
by  perspiration,  during  an  hour  and  a  quarter's  labor  in  a  very  hot  atmosphere, 
regained  8  oz.  by  immersion  in  a  warm  bath  at  95°,  for  half  an  hour.4 — The 
experiments  of  Dr.  Madden5  on  his  own  person  show  that  a  positive  increase 
usually  takes  place  in  the  weight  of  the  body,  during  immersion  in  the  warm 

1  We  have  a  remarkable  exception  to  this  general  statement,  however,  in  the  case  of 
Frogs  and  other  Batrachia,  which  are  characterized  by  the  softness  of  their  skins  and  the 
thinness  of  their  epidermic  covering ;  for  cutaneous  absorption  seems  in  them  to  be  no  less 
active  than  their  cutaneous  exhalation  and  respiration  are  well  known  to  be.  Thus  Frogs, 
which  habitually  live  in  a  moist  atmosphere,  seldom  or  never  drink ;  yet  when  they  have 
lost  fluid  by  exposure  to  hot  dry  air,  they  will  regain  their  weight  by  being  left  for  a  time 
upon  moist  sand ;  and  the  bladder,  which  serves  as  a  reservoir  of  water  for  cutaneous  exha- 
lation, though  previously  emptied,  will  be  refilled. 

a  See  a  collection  of  such  cases  in  Dr.  Madden's  "Experimental  Enquiry  into  the  Phy- 
eiology  of  Cutaneous  Absorption,"  p.  47. 

3  "  Medical  reports,"  vol.  i.  pp.  308—326.         4  "  Philosophy  of  Health,"  vol.  ii.  p.  396. 

*  Op.  cit.,  pp.  59—63. 


148  OF    ABSORPTION    AND    SANGUIFICATION 

bath,  even  though  there  is  at  the  same  time  a  continual  loss  of  weight  by  pul- 
monary exhalation,  and  by  transudation  from  the  skin.1  This  increase  was,  in 
some  instances,  as  much  as  5  drachms  in  half  an  hour;  whilst  the  loss  of  weight 
during  the  previous  half-hour  had  been  6£  drachms  :  so  that,  if  the  same  rate  of 
loss  were  continued  in  the  bath,  the  real  gain  by  absorption  must  have  been 
nearly  an  ounce  and  a  half.  Why  this  gain  was  much  less  than  in  the  cases  just 
alludcd-to,  is  at  once  accounted-for  by  the  faet,  that  there  was  no  deficiency,  in 
the  latter  case,  of  the  fluids  naturally  present  in  the  body. 

129.  There  are  certain  phenomena,  which,  if  accurately  recorded,  cannot  be 
aocounted-for  in  any  other  way,  than  by  admitting  that,  under  particular  circum- 
stances, a  considerable  amount  of  water  may  be  absorbed  from  the  vapour  of  the 
atmosphere.  The  following  are  among  the  most  satisfactory  and  circumstantial 
observations,  that  have  been  adduced  in  support  of  this  position.  Lining 
observed  that  his  body  on  one  occasion  increased  in  weight,  during  two  hours,  to 
the  amount  of  8^  oz.;  allowance  being  made  for  the  amount  of  fluid  ingested 
during  that  time,  and  for  the  quantity  passed-off  by  the  urine  and  by  cutaneous 
transpiration.2  Dr.  Jurin  affirms  that  he  ascertained  an  increase  of  18  oz.  to 
have  taken  place  during  a  night  passed  in  a  cool  room,  after  a  day's  exercise  and 
abstinence.3  It  is  stated  by  Dr.  Watson,4  that  a  lad  at  Newmarket,  having  been 
almost  starved,  in  order  that  he  might  be  reduced  to  a  proper  weight  for  riding 
a  match,  was  weighed  at  9  A.  M.,  and  again  at  10  A.  M.J  and  he  was  found  to 
have  gained  nearly  30  oz.  in  weight  in  the  course  of  this  hour,  though  he  had 
only  drunk  half  a  glass  of  wine  in  the  interim.  A  parallel  instance  was  related 
to  the  Author  by  the  late  Sir  Gr.  Hill,  then  Governor  of  St.  Vincent ;  a  jockey 
had  been  for  some  time  in  training  for  a  race,  in  which  that  gentleman  was  much 
interested,  and  had  been  reduced  to  the  proper  weight ;  on  the  morning  of  the 
trial,  being  much  oppressed  with  thirst,  he  took  one  cup  of  tea ;  and  shortly 
afterwards  his  weight  was  found  to  have  increased  6  Ibs.,  so  that  he  was  inca- 
pacitated for  riding. — Nearly  the  whole  of  the  increase  in  the  former  case,  and 
at  least  three-fourths  of  it  in  the  latter,  must  be  attributed  to  absorption  from 
the  vapour  of  the  atmosphere ;  probably,  however,  rather  through  the  lungs  than 
through  the  skin.  Tf  the  possibility  of  such  absorption  be  admitted,  we  are 
probably  to  attribute  to  it  the  chief  part  of  the  excess  of  watery  fluid  which  cannot 
be  otherwise  accounted-for,  in  the  following  instances. — Dr.  Hill5  relates  the  case 
of  a  diabetic  patient,  who  for  five  weeks  passed  24  Ibs.  of  urine  every  twenty-four 
hours ;  his  ingesta  during  the  same  period  amounted  to  22  Ibs.  At  the  com- 
mencement of  the  disease,  he  weighed  145  Ibs. ;  and  when  he  died,  27  Ibs.  of 
loss  had  been  sustained.  The  daily  excess  of  the  excretions  over  the  fluid  ingesta 
could  not  have  been  less  than  4  Ibs. ;  making  140  Ibs.  for  the  thirty-five  days 
during  which  the  complaint  lasted.  If  from  this  we  deduct  the  amount  of 
diminution  which  the  weight  of  the  body  sustained  during  the  time,  we  shall 
still  have  113  Ibs.  to  be  accounted  for,  which  can  only  have  entered  the  body 
from  the  atmosphere. — A  case  of  ovarian  dropsy  has  been  recorded  by  Mr.  Ford,6 
in  which  it  was  observed  that  the  patient,  during  eighteen  days,  drank  692  oz.  or 
43  pints  of  fluid,  and  that  she  discharged  by  urine  and  by  paracentesis  1298  oz. 
or  91  pints,  which  leaves  a  balance  of  606  oz.  or  38  pints,  to  be  similarly  accounted 
for.7 

1  That  part  of  the  function  of  cutaneous  transpiration,  which  consists  in  simple  exhala- 
tion, is  of  course  completely  checked  by  such  immersion  ;  but  that  which  is  the  result  of 
an  actual  secreting  process  in  the  cutaneous  glands  (CHAP.  xn.  Sect.  4.)  is  increased  by 
heat,  even  though  this  be  accompanied  with  moisture. 

"Philosophical  Transactions,"  1743,  p.  496. 

Klapp,  "  Inaug.  Dissert.,"  p.  30,  cited  by  Dr.  Madden 

"  Chemical  Essays,"  vol.  iii.  p.  100. 

*"  Trans,  of  Med.-Chirurg.  Soc.  of  Edinb.,"  vol.  ii. 

"  Medical  Communications,"  vol.  ii.  p.  130. 

In  this  case,  however,  as  in  others  of  a  similar  kind,  something  is  to  be  allowed  for  the 


ABSORPTION    FROM    THE     BODY    IN    GENERAL.          149 

130.  Not  only  water,  but  substances  dissolved  in  it,  may  be  thus  introduced. 
It  has  been  found  that,  after  bathing  in  infusions  of  madder,  rhubarb,  and 
turmeric,  the  urine  was  tinged  with  these  substances ;  and  that  a  garlic  plaster 
affected  the  breath,  when  every  care  was  taken,  by  breathing  through  a  tube  con- 
nected with  the  exterior  of  the  apartment,  that  the  odour  should  not  be  received 
into  the  lungs.1  Gallic  acid  has  been  found  in  the  urine,  after  the  external  appli- 
cation of  a  decoction  of  a  bark  containing  it;  and  the  soothing  influence,  in 
cases  of  neuralgic  pain,  of  the  external  application  of  cherry-laurel  water  is  weli 
known.  Many  saline  substances  are  absorbed  by  the  skin,  when  applied  to  it  in 
solution;  and  it  is  interesting  to  remark,  that,  contrary  to  what  happens  in  regard 
to  the  absorption  of  these  from  the  alimentary  canal,  they  are  for  the  most  part 
more  readily  discoverable  in  the  Absorbents  than  in  the  Veins.  This  is  probably 
due  to  the  fact,  that  the  imbibition  of  them  takes  place  entirely  according  to 
physical  laws ;  in  conformity  with  which  they  pass  most  readily  into  the  vessels 
which  present  the  thinnest  walls  and  the  largest  surface.  In  the  intestines,  the 
vascular  plexus  on  each  villus  is  not  only  very  extensive,' but  also  ensheaths  the 
lacteal  trunk ;  and  as  the  walls  of  the  veins  are  thin,  there  is  considerable  facility 
for  the  entrance  of  saline  and  other  substances  into  the  general  current  of  the 
circulation  :  but  in  the  skin,  the  lymphatics  are  distributed  much  more  minutely 
and  extensively  than  the  veins ;  and  soluble  matters,  therefore,  enter  them  in 
preference  to  the  veins.  The  absorbent  power  of  the  Lymphatics  of  the  skin  is 
well  shown  by  the  following  experiments.  A  bandage  having  been  tied  by 
Schreger  round  the  hind-leg  of  a  puppy,  the  limb  was  kept  for  twenty-four  hours 
in  tepid  milk;  at  the  expiration  of  this  period,  the  lymphatics  were  found  full  of 
milk,  whilst  the  veins  contained  none.  In  repeating  this  experiment  upon  a 
young  man,  no  milk  could  be  detected  in  the  blood  drawn  from  a  vein.  It  has 
been  shown  by  Miiller  that,  when  the  posterior  extremities  of  a  frog  were  kept 
for  two  hours  in  a  solution  of  prussiate  of  potass,  the  salt  had  freely  penetrated 
the  lymphatics,  but  had  not  entered  the  veins. — It  does  not  follow,  however,  from 
these  and  similar  experiments,  that  in  all  tissues  the  lymphatics  absorb  more 
readily  than  the  veins ;  for  as  the  capillary  blood-vessels  in  the  Lungs  are  much 
more  freely  exposed  to  the  surface  of  the  air-cells  than  are  the  lymphatics,  we 
should,  on  the  principles  just  now  stated,  expect  the  former  to  absorb  more 
readily.  This  appears  from  experiment  to  be  the  fact;  for,  when  a  solution  of 
prussiate  of  potass  was  injected  by  Mayer  into  the  lung,  the  salt  could  be  detected 
in  the  serum  of  the  blood  of  the  left  cavities  of  the  heart,  before  it  had  reached 
that  of  the  right. 

131.  Our  inferences  with  regard  to  the  ordinary  functions  of  the  Lymphatic 
system,  however,  must  be  rather  drawn  from  the  nature  of  the  fluid  which  it  con- 
tains, and  from  the  uses  subsequently  made  of  it,  than  from  such  experiments 
as  the  preceding.  We  shall  presently  see,  that  there  is  a  close  correspondence 
in  composition  between  the  Chyle  of  the  Lacteals,  and  the  Lymph  of  the  Lym- 
phatics ;  the  chief  difference  being  the  presence  of  a  considerable  quantity  of 
fatty  matter  in  the  former,  and  of  a  larger  proportion  of  the  assimilable  sub- 
stances (albumen  and  fibrin)  which  are  equally  characteristic  of  both  (§  134). 
This  evident  conformity  in  the  nature  of  the  fluid  which  these  two  sets  of  vessels 
transmit,  joined  to  the  fact  that  the  fluid  Lymph,  like  the  Chyle,  is  conveyed 
into  the  general  current  of  the  circulation,  just  before  the  blood  is  again  trans- 
mitted to  the  system  at  large,  almost  inevitably  leads  to  the  inference,  that  the 
lymph  is,  like  the  chyle,  a  nutritious  fluid,  and  is  not  of  an  excrementitious 
character,  as  maintained  by  Hunter  and  his  followers.2  On  the  other  hand,  the 

quantity  of  water  contained  in  the  solid  food  ingested ;  but  this  may  be  fairly  considered 
not  to  exceed  the  quantity  lost  by  pulmonary  and  cutaneous  exhalation,  and  discharged  in 
the  faecal  evacuations. 

1  Prof.  Dunglison's  "  Human  Physiology,"  7th  edit.  vol.  i.  p.  688. 

a  Since  the  time  of  Hunter,  who  first  brought  prominently  forwards  the  doctrine  alladed 


150  OF    ABSOKPTION    AND     SANGUIFICATION. 

close  resemblance  between  the  contents  of  the  Lymphatics,  and  diluted  Liquor 
Sanguinis,  seems  to  indicate  that  the  former  are  chiefly  derived  from  the  fluid 
portion  of  the  blood,  which  has  transuded  through  the  walls  of  the  capillary 
vessels ;  and  we  shall  presently  see  reason  to  believe,  that  this  transudation  is 
partly  for  the  purpose  of  subjecting  the  crude  materials,  which  may  have  been 
taken  up  direct  into  the  blood-vessels,  to  an  elaborating  or  preparatory  agency, 
such  as  it  seems  to  be  the  especial  object  of  the  Lacteal  system  to  exert  upon  the 
nutritive  substances  which  it  serves  to  introduce  into  the  circulation.  —  But  it 
seems  not  impossible,  that  there  may  be  another  source  for  the  contents  of  the 
Lymphatics.  We  have  already  had  to  allude,  on  several  occasions,  to  the  dis- 
integration which  is  continually  taking  place  within  the  living  body;  whether  as 
a  result  of  the  limited  duration  of  the  life  of  its  component  parts,  or  as  a  conse- 
quence of  the  decomposing  action  of  Oxygen.  Now  the  death  of  the  tissues  by 
no  means  involves  their  immediate  and  complete  destruction ;  and  there  seems 
no  more  reason  why  an  animal  should  not  derive  support  from  its  own  dead  parts, 
than  from  the  dead  body  of  another  individual.  Whilst,  therefore,  the  matter 
which  has  undergone  too  complete  a  disintegration  to  be  again  employed  as 
nutrient  material,  is  carried-off  by  the  excreting  processes,  that  portion  which  is 
capable  of  being  again  assimilated,  may  be  taken  up  by  the  Lymphatic  system. 
If  this  be  the  case,  we  may  say  with  Dr.  Prout,  that  "  a  sort  of  digestion  is  car- 
ried-on  in  all  parts  of  the  body." — It  may  be  stated,  then,  as  a  general  proposi- 
tion, that  the  function  of  the  Absorbent  System  is  to  take-up,  and  to  convey  into 
the  Circulating  apparatus,  such  substances  as  are  capable  of  appropriation  to  the 
nutritive  process;  whether  these  substances  be  directly  furnished  by  the  external 
world,  or  be  derived  from  the  disintegration  of  the  organism  itself.  We  have 
Been  that,  in  the  Lacteals,  the  selecting  power  is  such,  that  these  vessels  are  not 
disposed  to  convey  into  the  system  any  substances  but  such  as  are  destined  for 
this  purpose ;  and  that  extraneous  matters  are  absorbed  in  preference  by  the 
meseuteric  Blood-vessels.  The  case  is  different,  however,  with  regard  to  the 
Lymphatics ;  for  there  is  reason  to  believe  that  they  are  more  disposed  than  the 
venous  capillaries,  to  the  absorption  of  other  soluble  matters,  especially  when 
these  are  brought  into  relation  with  the  Skin,  through  which  the  lymphatic  ves- 
sels are  very  profusely  distributed. 

3. —  Of  the  Elaboration  of  the  Nutrient  Materials. — Sanguification. 

132.  The  alimentary  substances,  taken-up  by  the  Blood-vessels  and  Absorbents, 
seem  very  far  from  being  capable  of  immediate  application  to  the  nutrition  of 
the  body ;  for  we  find  that  they  are  not  conveyed  by  any  means  directly  into  the 
circulating  current,  but  that  those  which  enter  the  Gastro-intestinal  veins  are 
submitted  to  the  operation  of  the  Liver,  whilst  those  which  are  received  into  the 
Lacteals  are  subjected  to  a  kind  of  glandular  action  within  their  own  system ; 

to,  it  was  long  taught  (in  this  country  especially)  that  the  function  of  the  Lymphatics  is 
to  remove,  by  interstitial  absorption,  the  effete  matter,  which  is  destined  to  be  carried  out 
of  the  system;  and  any  undue  activity  in  this  process  (such  as  exists  in  ulceration),  and 
any  deficiency  in  its  energy  (such  as  gives  rise  to  dropsical  effusions,  and  other  collections 
of  the  same  kind),  "have  been  attributed  to  excess  or  diminution  in  the  normal  operation 
of  the  Absorbent  system.  All  that  we  at  present  know,  however,  of  the  process  of  Nu- 
trition, tends  to  the  belief  that  the  effete  matters  are  carried  off  by  the  Venous  system ; 
for  not  only  do  we  find  no  trace  in  the  Lymph  of  any  of  those  substances  which  are  des- 
tined for  elimination  as  excrementitious,  but  the  Lymphatic  vessels  are  either  absent 
altogether,  or  exist  in  but  very  small  numbers,  in  the  Nervo-Muscular  apparatus,  which 
undergoes  more  constant  interstitial  change,  and  produces  more  effete  matter  by  its  dis- 
integration, than  does  any  other  part  of  the  organism.  It  may  be  safely  affirmed  that 
there  is  not  a  single  fact  to  support  what  is  known  as  the  Hunterian  doctrine ;  which 
could  never  have  gained  currency  but  for  the  authority  of  its  great  teacher, — its  originator, 
perhaps,  having  been  rather  Hewson  than  Hunter. 


ELABORATION    OF   NUTRIENT    MATERIALS  —  SANGUIFICATION.        151 

the  newly-absorbed  materials  in  both  cases  undergoing  considerable  changes, 
which  tend  to  assimilate  them  to  the  components  of  the  Blood.  —  It  will  be  re- 
collected that  all  the  veins  which  return  the  blood  from  the  capillaries  of  the 
gastro-intestinal  canal,  converge  into  the  portal  trunk,  which  distributes  this 
blood,  charged  with  the  newly-absorbed  materials,  through  the  capillary  system 
of  the  Liver.  The  agency  of  this  gland  was  formerly  supposed  to  be  limited  to 
the  elimination,  from  the  blood  subjected  to  its  influence,  of  the  materials  of  the 
biliary  secretion ;  but  there  is  now  evidence  that  the  blood  itself  is  changed  by 
its  means,  in  a  manner  which  indicates  an  assimilating  as  well  as  a  depurating 
action.  The  blood  which  comes  to  the  Liver  from  the  alimentary  canal,  is  charged 
with  albuminous  matter  in  a  state  different  from  that  of  the  albumen  of  perfect 
blood  (§  183) ;  and  the  assimilation  of  this  would  appear,  from  the  observations 
and  experiments  of  M.  Cl.  Bernard  (§  185),  to  be  one  of  the  most  important 
functions  of  the  liver.  For  he  found  that  whilst  a  solution  of  egg-albumen,  in- 
jected into  the  jugular  vein,  speedily  occasioned  a  transudation  of  albumen  into 
the  urine,  no  such  transudation  occurred  when  a  similar  solution  was  injected 
into  the  vena  portae ;  so  that  the  albumen  must  have  undergone  seme  change  in 
passing  through  the  Liver,  which  rendered  it  no  longer  a  foreign  ingredient  in 
the  blood.  So,  again,  the  saccharine  matters  which  are  brought  to  the  Liver  in 
the  condition  of  grape-sugar  or  of  cane-sugar,  are  converted  by  its  agency  into 
*  liver-sugar;'  a  form  of  the  saccharine  principle,  of  whose  presence  the  blood  is 
much  more  tolerant  than  it  is  of  any  other,  as  is  shown  by  the  results  of  the  in- 
troduction of  these  sugars  into  different  parts  of  the  circulating  system.  For  if 
cane-sugar  be  injected  into  the  jugular  vein,  even  in  very  small  amount,  it 
speedily  appears  in  the  urine ;  but  it  may  be  injected  in  large  quantity  into  the 
vena  portae,  without  showing  itself  in  this  excretion.  On  the  other  hand,  the 
blood  can  tolerate  the  injection  of  liver-sugar  into  any  part  of  its  current,  to  an 
amount  not  less  than  240  times  that,  which,  in  the  case  of  cane-sugar,  will  in- 
volve its  immediate  escape  by  the  kidney.1  From  the  saccharine  compounds 
brought  to  the  Liver,  moreover,  it  appears  that  fatty  matter  can  be  generated ; 
but  as  the  introduction  of  this  substance  into  the  blood-vessels  ordinarily  takes 
place  through  a  different  channel,  the  action  of  the  liver  would  not  appear  to  be 
essential  to  its  assimilation;  and  it  has  been  found  by  M.  Bernard,  that  oil  may 
be  injected  into  the  general  circulation  without  exciting  any  violent  effort  at  its 
elimination.  —  There  is  evidence  that  the  Liver  may  be  subservient  even  to  the 
vital  transformation  of  the  components  of  the  blood.  For  it  has  been  observed 
by  Prof.  E.  H.  Weber,  that,  during  the  last  three  days  of  incubation  of  the 
chick,  the  liver  is  made  bright-yellow  by  the  absorption  of  the  yolk,  which  fills 
and  clogs  all  the  minute  branches  of  the  portal  veins ;  and  that  in  time  the 
materials  of  the  yolk  disappear,  part  being  developed  into  blood-corpuscles  and 
other  constituents  of  blood,  which  enters  the  circulation,  and  the  rest  forming 
bile,  and  being  discharged  into  the  intestine.2  And  if  as  asserted  by  M.  Bernard, 
the  quantity  of  fibrin  is  relatively  greater  in  the  blood  of  the  hepatic  vein,  than 
in  the  portal  blood,  the  metamorphosis  of  albumen  into  fibrin  must  be  admitted 
to  be  one  of  the  functions  of  the  liver:3  upon  this  point,  however,  he  is  bv  no 
means  in  accordance  with  other  observers  (§  185). 

1  See  M.  Magendie,  in  »  L'Union  Medicale,"  1849,  Nos.  72,  75,  79. 

2  "  HenlS  and  Pfeufer's  Zeitschrift,"  1846.— See  also  \  167. 

3  See  on  the  whole  of  this  subject,  M.  Cl.  Bernard's  Lectures  on  the  "  Functions  of  the 
Liver,"  delivered  before  the  College  de  France,  and  published  in  "  L'Union  Medicale"  for 
1850.     [M.  Bernard's  opinions  seem  to  have  undergone  some  change  since  the  publication 
of  the  lecture  referred  to  in  the  note ;  for  in  those  delivered  before  the  College  of  France, 
in  1853-4,  he  makes  the  following  statements,  after  detailing  the  analyses  of  Simon  and 
another  chemist,  whom  he  does  not  name,  to  the  effect  that  the  blood  of  the  hepatic  vein 
contains  less  fibrine  than  that  of  the  portal.      "  In  the  liver  the  hydro-carbonaceous  ingre- 
dients of  the  fibrine  are  used  to  make  sugar,  and  the  nitrogenized  that  are  left,  to  make 
bile.     Experiments  show  that  the  sugar  and  bile  are  in  proportion  to  the  fibrine  destroyed, 


152  OF    ABSORPTION    AND     SANGUIFICATION. 

133.  The  whole  of  the  Lacteal  and  Lymphatic,  system  may  be  looked-upon 
as  constituting  one  great  Assimilating  Gland,  dispersed  through  the  body  at 
large ;  for  it  does  not  differ  in  any  essential  particular  from  what  the  Kidney  or 
the  Testis  would  be,  if  it  were  simply  unravelled,  and  its  convoluted  tubuli  spread 
through  the  entire  system,  yet  still  all  discharging  their  secreted  products  by  a 
common  outlet.  In  the  cold-blooded  Vertebrata,  the  Absorbent  system  appears 
to  attain  a  relatively  greater  development,  than  it  does  in  the  higher  classes;  but 
the  difference  really  lies  in.  the  greater  extension,  in  the  former,  of  those  glandu- 
lar elements  which  are  more  concentrated  in  the  latter  (See  PRINC.  OF  COMP. 
PHYS.,  §§  184 — 187). —  The  Lacteals  are  connected,  very  near  their  origin,  with 
those  peculiar  bodie.>  which  are  known  as  Peyer's  Glands.  These  may  be  either 

'solitary'    or    'agminated;'     the    former 

FIG.  37.  present  themselves  along  nearly  the  whole 

length  of  the  intestinal  canal,  whilst  the 
latter  are  restricted  to  the  small  intestine, 
being  most  abundant  at  the  lower  part  of 
the  ileum.  In  whatever  portion  of  the 
length  of  the  canal  they  may  occur,  they 
are  always  limited  in  situation  to  that 
part  of  its  periphery  which  joins  the  me- 
sentery. Each  '  Peyerian  gland/  in  a 
healthy  mucous  membrane,  presents  the 
appearance  of  a  circular  white,  slightly- 
raised  spot,  about  a  line  in  diameter,  over 
which  the  membrane  is  usually  less  beset 
with  villi,  and  is  very  often  entirely  desti- 
tute of  them;  and  it  is  surrounded  by  a 
ring  of  openings,  which  are  the  orifices  of 
a  set  of  caecal  follicles  disposed  in  a  zone 

Portion  of  the  mucous  surface  of  the  end  of  around  ifc  ,pj  37^  Tfae  <  p  erian 
the  Human  ileum.  moderately  magnified,  show-  .  i  ,  x-ni  <->o-\  • 

ing  the  Peyerian  Glands,  the  orifices  of  the  fol-  Patches      (Fig.    88)    present    aggregations 
licles,  and  the  villi.  of  these  spots,  varying  in   number  from 

two  upwards,  but  every  one  of  their  indi- 
vidual components  having  precisely  the  same  structure  as  the  solitary  gland.  This 
appears,  from  the  recent  researches  of  Briicke,  Kolliker,  and  others,  not  to  be 
(as  formerly  supposed)  a  proper  gland-vesicle  whose  contents  are  surrounded  by 
a  limitary  membrane ;  but  to  be  a  sort  of  capsule,  whose  walls  are  composed  of 
indistinctly-fibrillated  connective  tissue  with  interspersed  nuclei,  and  whose  con- 
tents are  but  imperfectly  differentiated  from  the  tissues  in  which  the  gland  is 
imbedded.  These  contents  are  made-up  of  a  granular  '  plasma/  containing  fatty 
and  albuminous  molecules  of  various  sizes,  with  nuclear  particles,  and  a  few  cells 
(Fig.  39)  ;  altogether  presenting  an  appearance  of  being  the  seat  of  rapid  changes 
of  progressive  metamorphosis.  Each  capsule  is  surrounded  by  a  close  vascular 
network ;  and  according  to  the  observations  of  Frei,  which  have  been  confirmed 
by  Kolliker/  capillary  vessels  pass  freely  into  the  midst  of  its  contents,  and  then 
return  by  loops,  as  shown  in  Fig.  40.  That  these  bodies  are  appendages  to  the 
Lacteal  system,  appears  not  only  from  their  peculiar  position,  from  their  close 
conformity  in  structure  to  the  Mesenteric  glands,  and  from  the  fact  that  the 
number  of  lacteals  which  may  be  traced  during  digestion  from  the  Peyerian 

The  fibrine  of  the  hepatic  blood  gives  to  it  properties  that  might  be  said  to  arise  from  an 
excess  of  this  substance,  namely,  rapidity  of  coagulation  and  firmness  of  the  clot,  dif- 
fering in  this  respect  from  the  portal  blood,  which  coagulates  very  slowly  and  is  very 
soft.  It  is  not  the  quantity  of  fibrine,  however,  which  produces  this  peculiarity  of  action  ; 
it  is  due  rather  to  a  chemical  influence  depending  on  the  nervous  system."1 — ED.] 
'  "  Mikroskopische  Anatomic,"  band  ii.,  $  171. 

1  Bernard  and  Robin  on  the  Blood ;  translated  by  W.  F.  Atlee,  M.  D.     Philada.,  1854, 


ELABORATION    OF   NUTRIENT    MATERIALS. — PETER'S    GLANDS.        153 


patches  is  greater  than  that  in  other  parts  of  the  intestine ;  but  also  from  the 
results  of  direct  experiment,  it  having  been  found  possible  by  Briicke   to  fill  the 


FIG.  38. 


FIG.  39. 


A,  Portion  of  a  patch  of  Peyerian  Glandules  from  the 
Ileum  of  the  Pig,  as  seen  from  the  deep  surface,  the  se- 
rous, muscular,  and  areolar  coats  having  been  dissected- 
off;  the  darker  vesicles  are  open  and  empty,  the  paler 
closed  and  full ;  magnified  3  diameters  : — B,  two  of  these 
vesicles,  viewed  from  the  inner  surface  of  the  intestine, 
one  of  them  closed  and  full,  the  other  open  and  empty, 
with  villi  and  apertures  of  mucous  follicles  in  their 
neighbourhood;  magnified  15  diameters. 


Vertical  section  of  two  of  the  Peye- 
rian  Glandules  from  the  Ileum  of  the 
Pig,  one  of  them  closed  and  full,  the 
other  open  and  empty,  with  theii  neigh- 
bouring villi ;  magnified  15  diameters  : 
—  or,  cellular  contents  of  the  vesicle  j 
magnified  250  diameters. 


Peyerian  glandulse  by  injection  from  the  absorbents. — In  their  course  tnrough 
the  mesentery,  the  Lacteals  pass  into  the  bodies  known  as  the  Mesenteric  Glands, 
which  stand  in  the  same  relation  to  them  that  the  Absorbent  Glands  of  the  body 
generally  do  to  the  Lymphatics;  and  as  the  structure  of  these  appendages  ia 
everywhere  the  same,  one  description  will  apply  equally  to  all.  According  to  the 
recent  investigations  of  Briicke  (loc.  cit.),  Kolliker,2  and  others,  each  absorbent 
gland  is  enclosed  by  a  sheath  or  capsule  of  fibrous  tissue,  which  sends  inwards  a 
number  of  thin  lamella,  so  disposed  and  connected  together,  as  to  constitute  a 
tolerable  regular  areolated  framework  pervading  the  entire  gland  (Fig.  41,  A) 
The  rounded  'alveoli'  thus  formed  (Fig.  41,  B)  are  filled  with  a  greyish-white 
pulp,  which  agrees  in  all  its  characters  with  that  of  the  Peyerian  bodies,  and 
which  is  penetrated,  like  the  latter,  by  a  fine  capillary  plexus.  These  'alveoli' 
seem  to  be  in  free  communication  both  with  the  vasa  afferentia  and  the  vasa  cffe- 

1  See  his  Memoir  '  Ueber  den  Bau  und  die  physiologische  Bedeutung  der  Peyerischen 
Driisen,'  in  "  Denkschrifren  der  Kaiserlichen  Akademie  der  Wissenschaften,"  Wien,  1850 
(an  abstract  of  which  is  contained  in  the  "  Edinb.  Monthly  Journal"  for  Nov.  1850) ;  and 
his  subsequent  papers  'Ueber  die  Aufsaugung  des  Chylus,'  &c.,  in  "  Sitzungsberichte  d. 
Wiener  Akad.,"  Dec.  1852,  Jan.  1853,  and  March,  1853.  See  also  Bruch,  in  "  Siebold 
and  Kolliker's  Zeitschrift,"  April,  1853.  Their  results  appear  to  prove  quite  conclusively, 
that  the  Peyerian  glandulae  are  really  appendages  to  the  Absorbent  system,  corresponding 
in  every  respect,  save  their  situation,  to  the  mesenteric  and  lymphatic  glands ;  and  hence 
that  their  open  or  follicular  condition,  which  has  been  so  frequently  met-with  as  to  have 
been  regarded  by  Profs.  Krause  and  Allen  Thomson  as  a  normal  stage  in  their  history  (see 
especially  the  Memoir  by  the  latter  in  "  Goodsir's  Annals  of  Anatomy  and  Physiology," 
No.  1),  has  not  the  signification  formerly  attached  to  it  In  Dr.  A.  Thomson's  observations, 
•which  were  chiefly  made  on  the  Pig,  some  patches  presented  no  openings,  in  others  almost 
all  the  vesicles  were  open  and  empty,  while  in  a  third  set  open  and  closed  vesicles  were 
found  irregularly  mingled  in  the  same  patch  (Figs.  38,  39) :  and  the  Author  has  himself 
frequently  met  with  the  follicles  in  the  open  condition,  in  cases  in  which  there  was  no  ap- 
pearance of  disease.  It  remains  as  a  point  for  inquiry,  therefore,  whether  there  is  not  a 
continual  dying-away  and  new  production  of  these  bodies ;  a  hypothesis  which  would  in 
some  degree  account  for  the  remarkable  variety  in  their  number  and  seat,  which  presents 
itself  in  different  individuals. 

*  "  Mikroscopische  Anatomic,"  band.  ii.  \  250 


154 


OF    ABSORPTION    AND     SANGUIFICATION. 


rentia;  and  the  fluid  brought  to  the  glands  by  the  former,  must  traverse  their 
pulp,  before  finding  its  way  into  the  latter.  The  large  increase  which  is  observa- 
ble in  the  corpuscles  floating  in  the  chyle  of  the  efferent  lacteals,  as  compared 


FIG.  40. 


Horizontal  Section  through  the  middle  plane  of  three  Peyerian  Glands  in  the  Rabbit, 
showing  the  distribution  of  the  blood-vessels  in  the  interior. 

with  that  of  the  afferent,  and  the  close  resemblance  which  they  bear  to  the  cor- 
puscles of  the  mesenteric  glands,  leaves  it  scarcely  doubtful  that  they  are  partly 
derived  from  those  bodies.  Neither  the  Absorbent  nor  the  Peyerian  glands, 

FIG.  41. 


Section  of  Lymphatic  Gland,  showing  a  a, 
the  fibrous  tissue  which  forms  its  exterior;  b  6, 
superficial  vasa  inferentia;  c  c,  larger  alveoli 
near  the  surface ;  d  d,  smaller  alveoli  of  the 
interior;  e  e,  fibrous  walls  of  the  alveoli. 


Section  of  one  of  the  alveoli  of  a 
Lymphatic  Gland;  o  a,  its  fibrous 
envelope ;  b  b,  prolongations  from 
this,  intersecting  and  subdividing  the 
general  cavity  ;  c  c,  nuclei  of  the  fibre- 
cells  ;  d,  separate  fibre-cells. 


however,  are  to  be  regarded  in  any  other  light,  anatomically,  than  as  dilatations 
of  the  Absorbents  themselves,  with  a  largely-increased  development,  both  of  the 
fibrous  tissues  which  bound  them,  and  of  the  cellular  elements  which  they  con- 


COMPOSITION    AND    PROPER! 'IBS    OF    CHYLE    AND    LYMPH.  155 

tain.  Arid  physiologically  they  may  be  supposed  to  afford  a  concentration  (so  to 
speak)  of  that  metamorphic  power,  which  is  diffused  in  a  feebler  degree  through 
the  whole  Absorbent  system. 

134.  Composition  and  properties  of  the  Chyle  and  Lymph. — The  chief  chemi- 
cal difference  between  these  fluids,  consists  in  the  much  smaller  proportion  of 
solid  matter  in  the  Lymph,  and  in  the  almost  entire  absence  of  fat,  which  is  an 
important  constituent  of  the  Chyle.  This  is  well  shown  in  the  following  com- 
parative analyses,  performed  by  Dr.  G.  0.  Rees,  of  the  fluids  obtained  from  the 
lacteal  and  lymphatic  vessels  of  an  Ass,  previously  to  their  entrance  into  the 
thoracic  duct;  the  animal  having  had  a  full  meal  seven  hours  before  its  death. 

Chyle.  Lymph. 

Water 90-237  96-536 

Albuminous  matter  (coagulable  by  heat) 3-516           1-200 

Fibrinous  matter  (spontaneously  coagulable) 0-370           0-120 

Animal  extractive  matter,  soluble  in  water  and  alcohol 0-332           0-240 

Animal  extractive  matter,  soluble  in  water  only 1-233           1-319 

Fatty  matter 3-601           a  trace 

Salts  ; — Alkaline  chloride,  sulphate,  and  carbonate,  with  traces 

of  alkaline  phosphate,  oxide  of  iron 0-711           0-585 


100.000       100-000 

The  Lymph  obtained  from  the  neck  of  a  Horse  has  been  analysed  by  Nasse,  with 
nearly  the  same  result.  He  found  it  to  contain  95  per  cent  of  water;  and  the  5 
per  cent  of  solid  matter  was  chiefly  composed  of  albumen  and  fibrin,  with  watery 
extractive,  scarcely  a  trace  of  fat  being  discoverable.  The  proportion  of  saline 
matter  was  found  to  be  remarkably  coincident  with  those  which  exist  in  the  serum 
of  the  blood;  as  might  be  expected  from  the  fact,  that  the  fluid  portion  of  the 
lymph  must  have  its  origin  in  that  which  has  transuded  through  the  blood-vessels : 
the  absolute  quantity,  however,  is  rather  less.  A  similar  analysis  of  the  Chyle  of 
a  Cat  by  Nasse,  has  given  results  very  closely  correspondent  with  that  of  Dr. 
Rees;  for  the  proportion  of  water  was  90'5  per  cent ;  and  of  the  9*5  parts  of  solid 
matter,  the  albumen,  fibrin,  and  extractive  amounted  to  more  than  5,  and  the  fat 
to  more  than  3  parts.1 — Dr.  Rees  has  also  analysed  the  fluid  of  the  Thoracic  duct 
of  Man;2  and  found  it  to  consist  of  9048  per  cent  of  water,  7-08  parts  of 
albumen  and  fibrine,  1-08  parts  of  aqueous  and  alcoholic  extractive,  and  0-90  of 
fatty  matter,  with  0'44  per  cent  of  salines.  Thus  the  composition  of  this  fluid 
would  seem  to  resemble  that  of  the  Lymph,  rather  than  that  of  the  Chyle ;  the 
proportion  of  fatty  to  that  of  the  albuminous  matter  being  very  small.  This, 
however,  might  have  been  very  probably  due  to  the  circumstance,  that  the  subject 
(an  executed  criminal)  from  whose  body  the  fluid  was  obtained,  had  eaten  but 
little  for  some  hours  before  his  death. 

135.  The  characters  of  the  Chyle  drawn  from  the  larger  absorbent  trunks  near 
their  entrance  into  the  Receptaculum  chyli,  are  very  different  from  those  of  the 
fluid  first  absorbed  into  the  Lacteals ;  for  during  the  passage  through  these  vessels 
and  the  Mesenteric  glands,  it  undergoes  important  alterations,  which  gradually 
assimilate  it  to  Blood.  The  chyle  drawn  from  the  lacteals  that  traverse  the 
intestinal  walls,  contains  Albumen  in  a  state  of  complete  solution ;  but  it  is 
generally  destitute  of  the  power  of  coagulation,  no  Fibrine  being  present  in  it. 
The  Salts,  also,  are  completely  dissolved ;  but  the  Oily  matter  presents  itself  in 
the  form  of  globules  of  variable  size.3  It  is  generally  supposed,  that  the  milky 
coloui  of  the  chyle  is  owing  to  these;  but  Mr.  Gulliver  has  pointed  out4  that  it  is 

1  "Wagner's  Handworterbuch,"  band  i.,  Art.  'Chylus.' 
a  "  Philosophical  Transactions,"  1842. 

3  These  oily  globules  are  more  abundant  in  the  Chyle  of  Man  and  of  the  Carnivora  than 
in  that  of  the  Herbivora;  their  diameter  has  been   observed  to  vary  from  1-25,000  to 
1 -2000th  of  an  inch. 

4  "  Gerber's  General  Anatomy,"  Appendix,  p.  88;  and  "Hewson's  Works"  (Sydenhnm 
Society's  Edition),  notes  to  pp.  82 — 88. 


156  OF    ABSORPTION    AND    SANGUIFICATION. 

really  due  to  an  immense  multitude  of  far  more  minute  particles  which  he 
describes  as  forming  the  molecular  base  of  the  chyle.  These  molecules  are  most 
abundant  in  rich,  milky,  opaque  chyle;  whilst  in  poorer  chyle,  which  is  semi- 
transparent,  or  opaline,  the  particles  float  thinly  or  separately  in  the  transparent 
fluid,  and  often  exhibit  the  vivid  motions  common  to  the  most  minute  molecules 
of  various  substances.  Such  is  their  minuteness,  that,  even  with  the  best  instru- 
ments, it  is  impossible  to  form  an  exact  appreciation  either  of  their  form  or  their 
dimensions.  They  seem,  however,  to  be  generally  spherical ;  and  their  diameter 
may  be  estimated  at  between  l-36,000th  and  l-24,000th  of  an  inch.  Though 
remarkable  for  their  urichangeableness,  when  subjected  to  the  action  of  numerous 
re-agents  which  quickly  affect  the  proper  Chyle-corpuscles,  they  are  readily 
soluble  in  ether,  the  addition  of  which  causes  the  whole  molecular  base  instantly 
to  disappear,  not  a  particle  of  it  remaining ;  whence  it  may  be  inferred  that  they 
consist  of  oily  or  fatty  matter.  That  they  do  not  ordinarily  tend  to  coalesce,  is 
probably  due  to  the  coating  of  albumen  which  they  obtain  through  their  diffusion 
in  an  albuminous  fluid ;  if,  however,  this  be  dissolved  by  acetic  acid,  or  even  by 
the  addition  of  water,  many  of  the  molecules  are  lost-sight-of,  and  oil-drops  appear 
in  their  place%  The  milky  colour  which  the  Serum  of  blood  sometimes  exhibits 
in  healthy  subjects  (§  177),  is  due  to  an  admixture  of  this  molecular  base  with 
the  circulating  fluid. 

136.  During  the  passage  of  the  Chyle  through  the  absorbents  on  the  intestinal 
edge  of  the  mesentery,  towards  the  Mesenteric  Glands,  its  character  changes  in 
several  important  particulars.  The  presence  of  Fibrin  begins  to  manifest  itself, 
by  the  slight  coagulability  of  the  fluid  when  withdrawn  from  the  vessels }  and  a 
few  Chyle-corpuscles  make  their  appearance.  The  diameter  of  these  bodies  varies 
from  l-7HOth  to  l-2600th  of  an  inch:  the  average  being  about  14600th.  The 
smallest  among  them  (Fig.  42,  6,  c)  seem  to  be  in  the  condition  of  nuclei;  in 
those  a  little  larger  (d,  e)  the  cell-wall  is  beginning  to  be  differentiated  from  the 
nucleus ;  whilst  in  those  of  greatest  diameter  (/",  g,  h,  i)}  the  cellular  character 
is  very  distinct,  and  the  nucleus  may  be  plainly  seen  in  the  interior,  especially 
after  the  addition  of  a  little  water  or  acetic  acid.  They  occasionally  exhibit 
curious  changes  of  form  (a,  a) ;  in  this  respect  corresponding  with  the  Colourless 
corpuscles  of  the  blood  (§  164),  which  are  probably  the  same  bodies  in  a  more 
advanced  stage.  A  great  increase  in  the  number  of  these  corpuscles  is  apparent 

in  the  fluid  of  the  efferent  lacteals ;  and  there  is 
FIG.  42.  also  a  further  augmentation  in  the  proportion  of 

Fibrin. — The  Chyle  drawn  from  the  lacteals  that 
intervene  between  the  Mesenteric  glands  and  the 
Receptaculum,  possesses  a  pale  reddish-yellow 
colour ;  and,  when  allowed  to  stand  for  a  time,  it 
undergoes  a  regular  coagulation,  separating  into 
clot  and  serum.  The  former  is  a  consistent  gela- 
tinous mass,  which,  when  examined  with  the  mi- 
croscope, is  found  to  include  the  Corpuscles,  each 
of  them  surrounded  by  a  delicate  film  of  oil ;  the 
Fibrin  of  which  it  is  principally  composed,  differs 
remarkably  from  that  of  the  blood,  in  its  inferior 
~,  ,  tendency  to  putrefaction  :  whence  it  may  be  in- 

Uh yie-corpwclesin  various  phases : —  /»          i     i         •     i  j  •..  i   ± 

a  „,  stellate  form  occasionally  seen  af-  f^rred  tl.mt  lfc  has  D0t  Vet  undergone   its   Complete 

ter  escape  of  their  contents;  b  b,  free  vitahzation.  The  serum  contains  the  Albumen 
nuclei;  c,  a  nucleus  surrounded  by  a  and  salts  in  solution,  and  a  proportion  of  the  Cor- 
few  granules;  d,  e,  small  cells,  some  puscles  suspended  in  it.  It  is  curious,  however, 
with  distinct  nucleus;/^,  larger  cells,  th  t  considerabie  differences  in  the  perfection  of 

one  with  a  visible  nucleus ;  h,  similar  Al  ,     .  ,  .     .L     ,  •?      ,  , 

cell  after  addition  of  water; ,-,  similar  the  coagulation,  and  m  its  duration,  should  present 
sell  after  addition  of  acetic  acid.  themselves  in  different  experiments.  Sometimes 

the  chyle  sets  into  a  jelly-like  mass,  which,  with- 


COMPOSITION  AND    PROPERTIES    OF   CHYLE   AND    LYMPH. 


157 


out  any  separation  into  coagulum  and  serum,  liquefies  again  at  the  end  of  half  an 
hour,  and  remains  in  this  state.  This  change  takes  place  in  the  true  coagulum 
also,  if  it  be  kept  moist  for  a  sufficient  length  of  time. — The  Chyle  from  the 
Receptaculm  and  Thoracic  duct  coagulates  quickly,  often  almost  instantaneously ; 
and  few  or  none  of  the  corpuscles  remain  in  the  serum.  The  fluid  drawn  from 
the  Thoracic  duct,  and  from  the  Absorbent  vessels  which  empty  their  contents 
into  it,  is  frequently  observed  to  present  a  decided  red  tinge,  which  increases  on 
exposure  to  the  air.  This  tinge  appears  to  be  due  to  the  presence  of  Red  blood- 
corpuscles  in  an  early  stage  of  formation  (§  168).  The  ordinary  corpuscles  more- 
over, have  a  more  distinctly  cellular  character  than  those  of  the  chyle  and  lymph, 
and  they  are  of  larger  size,  their  diameter  usually  ranging  from  about  1 -2600th  to 
l-2900th  of  an  inch  :  in  these  particulars,  they  correspond  with  the  Colourless 
corpuscles  of  the  Blood  ;  as  also  in  the  change  they  exhibit  on  the  action  of  acetic 
acid,  which  brings  into  view  three  or  four  large  central  particles. 

137.  The  aspect  of  the  Lymph  greatly  differs  from  that  of  the  Chyle,  the 
former  being  nearly  transparent,  while  the  latter  is  opaque  or  opalescent ;  and 
this  difference  is  readily  accounted-for,  when  the  assistance  of  the  microscope  is 
sought,  by  the  entire  absence  from  the  Lymph  of  that  '  molecular  base'  which  is 
so  abundant  in  the  Chyle.     A  considerable  number  of  corpuscles  are  generally 
present  in  it ;  and  these,  like  the  chyle-corpuscles,  very  closely  correspond  with 
the  colourless  corpuscles  of  the  Blood  (§  164).     Their  amount,  however,  is  ex- 
tremely variable;  as  is  also  that  of  the  oil-globules,  which  sometimes  occur, 
whilst  in  other  instances  none  can  be  discovered.     Lymph  coagulates  like  chyle ; 
a  colourless  clot  being  formed,  which  incloses  the  greater  part  of  the  corpuscles. 

138.  The  fluid  drawn  from  the  Thoracic  Duct,  consisting  as  it  does  of  an  ad- 
mixture of  Chyle  and  Lymph,  will  probably  vary 

in  its  character  and  composition,  according  to  the 
predominance  of  the  former,  or  of  the  latter,  of 
these  constituents. — From  the  observations  made 
by  Bidder  and  Schmidt,1  on  the  quantity  of  fluid 
discharged  from  the  thoracic  ducts  of  dogs  and 
cats  immediately  after  death,  it  is  inferred  by 
them  that  the  total  amount  of  mingled  lymph  and 
chyle  which  is  daily  poured  into  the  Subclavian 
vein  of  Man,  is  no  less  than  28  f  Ibs.,  or  fully  as 
much  as  the  entire  mass  of  the  blood,  —  its  solid 
constituents,  however,  being  not  more  than  from 
one-fourth  to  one-third  the  amount  contained  in 
the  blood.  Of  the  whole  quantity  thus  dis- 
charged, it  is  estimated  that  only  about  6^  Ibs. 
would  be  Chyle  derived  from  ingested  aliment; 
the  remainder  being  Lymph,  which  has  passed- 
out  of  the  blood-current  in  the  course  of  its  cir- 
culation, only  to  be  returned  to  it  again. 

139.  The  movement  of  the  fluids  taken-up  by  the 
Absorbent  vessels,  seems  to  depend  upon  a  combi- 
nation of  different  agencies.    The  lower  Vertebrata 
are  provided  with  'lymphatic  hearts/  (Fig.  43) 
or  pulsatile  cavities,  by  which  important  assistance 
is  given  in  the  onward  flow;  but  no  such  aid  is 
afforded  in  Man  or  in  the  Mammalia;  yet  it  is 
obvious  that  a  considerable  vis  a  tergo  must  exist, 

since,  if  the  thoracic  duct  be  tied,  it  is  speedily  distended  below  the  ligature, 
even  to  bursting.  The  Absorbent  vessels,  like  the  veins,  have  a  fibrous  coat;  into 


[Fio.  43. 


Lymphatic  heart  (9  lines  long, 
4  lines  broad)  of  a  large  species 
of  serpent,  the  Python  bivittatus, 
after  E.  Weber.  4.  The  external 
cellular  coat.  5.  The  thick  mus- 
cular coat.  Four  muscular  co- 
lumns run  across  its  cavity,  which 
communicates  with  three  lympha- 
tics (1  —  one  only  is  here  seen) 
with  two  veins  (2,  2).  6.  The 
smooth  lining  membrane  of  the 
cavity.  7.  A  small  appendage,  or 
auricle,  the  cavity  of  which  is  con- 
tinuous with  that  of  the  rest  of  th 
organ.] 


Verdauungs-safte  und  Stoffwechsel,"  gg  224^  285. 


158  OF    ABSORPTION    AND    SANGUIFICATION. 

which  the  muscular  fibre-cells  enter  largely,  and  which  is  therefore  contractile ; 
and  it  has  been  found  by  Prof.  Kolliker,  that  when  the  wire  of  an  electro- 
magnetic apparatus  was  applied  to  some  well-filled  lymphatics  on  the  skin  of  a 
boy's  foot,  soon  after  the  removal  of  the  leg  by  amputation,  the  stimulus  occa- 
sioned a  diminution  in  their  diameter  by  at  least  one-half,  and  this  not  sud- 
denly, but  in  the  course  of  between  half  a  minute  and  a  minute.1  The  same 
excellent  anatomist  has  observed  that  the  lymphatic  vessels  in  the  tail  of  a  Tad- 
pole empty  themselves  by  contraction  after  death,  and  then  dilate  again  to  their 
former  size,  just  as  the  smaller  arteries  do  under  the  like  circumstances ; 2  and 
this  fact  is  in  accordance  with  the  emptiness  of  the  Absorbent  system,  which 
usually  presents  itself  in  Man  some  little  time  after  death.  Hence  it  seems 
probable  that  a  regular  propulsion  of  their  contents  during  life,  may  be  effected 
by  alternate  contractions  and  dilatations  of  successive  portions  of  the  vessels, 
slowly  repeated  at  intervals.3 — There  are,  however,  certain  auxiliary  forces.  For, 
in  the  first  place,  a  part  of  the  movement  may  be  attributed  to  the  vis  a  tergo, 
which  is  produced  by  the  continual  introduction  of  fresh  fluid  into  the  rootlets, 
so  to  speak,  of  the  vascular  tree ;  and  this  more  especially  in  the  case  of  the 
lacteals,  since  the  muscularity  of  the  villi  seems  to  enable  them  to  act  as  so  many 
minute  force-pumps,  whereby  the  fluid  which  they  have  imbibed  may  be  impelled 
onwards  (§  120).  It  may  be  thought  that,  from  the  extreme  distensibility  of  the 
walls  of  the  absorbents,  this  force  would  be  rather  expended  in  dilating  them, 
than  in  pushing-on  the  current  of  liquid  which  they  contain ;  but'  it  must  be 
borne  in  mind  that  they  are  for  the  most  part  closely  surrounded  with  tissues 
which  exert  a  certain  degree  of  pressure  upon  them,  and  that  this  is  much  greater 
during  life  than  after  death.  Further,  in  all  the  movable  parts  of  the  body,  as- 
sistance is  doubtless  afforded  (as  it  is  to  the  circulation  in  the  Veins,  CHAP.  vi. 
Sect.  4)  by  the  occasional  pressure  exercised  upon  the  Absorbents  by  the  sur- 
rounding tissues;  for  while  this  pressure  is  operating,  it  will  tend  to  empty  them 
of  their  contents,  which  are  only  permitted  by  their  valves  to  pass  in  one  direc- 
tion ;  and  when  the  pressure  is  relaxed,  they  will  be  refilled  from  behind. 

140.  It  appears  obvious,  from  what  has  been  stated,  that  we  are  to  regard  the 
entire  Absorbent  system  as  a  great  blood-making  gland,  (§  133),  designed  to 
exert  a  certain  power  of  conversion  or  vitalization  over  the  matters  which  enter 
it,  either  from  the  alimentary  canal,  or  from  the  body  in  general. — In  the  case 
of  the  Lacteal  portion  of  the  system,  there  seems  to  be  a  strong  indication,  that 
one  part  of  the  converting  process  consists  in  the  intimate  admixture  which  the 
albuminous  constituent  of  the  chyle  undergoes  with  its  fatty  constituent,  owing 
to  the  subdivision  of  the  latter,  and  its  diffusion  through  an  albuminous  fluid. 
And  the  effects  of  this  admixture  are  peculiarly  shown  by  the  tenacity  with 
which  fat  is  incorporated  with  albumen  and  fibrin,  so  that  it  is  difficult  to  sepa- 
rate them;  this  incorporation,  it  seems  probable,  having  a  peculiar  reference  to 
the  very  first  process  of  cytogenesis,  in  which  molecules,  of  fatty  matter  seem 
always  to  be  present,  in  close  collocation  with  albuminous  particles  (See  PRINC. 
OF  GEN.  PHYS.).  As  already  pointed  out,  the  'plasticity'  of  the  different  albu- 
minous compounds  holds  such  a  direct  relation  to  the  quantity  of  fat  they  con- 
tain (within  certain  limits),  that  we  can  scarcely  help  looking  at  this  incorpora- 
tion as  one  of  the  most  important  parts  of  the  assimilating  process.  And  thus 

1  "  Kolliker  and  Siebold's  Zeitschrift,"  1849. 

*  "Annales  des  Sciences  Naturelles,"  2ieme  S^r.,  Zool.,  torn.  vi.  p.  99. 

8  A  regular  rhythmical  movement  of  the  veins  of  the  Bat's  wing,  obviously  sustained  by 
their  independent  contractility,  has  been  observed  by  Mr.  Wharton  Jones  ("  Philosophical 
Transactions,"  1852,  p.  131).  The  existence  of  such  a  movement  in  the  Veins  of  a  part, 
as  an  auxiliary  propulsive  force,  obviously  strengthens  the  probability  of  its  occurrence 
in  the  Lymphatics,  as  the  principal  propelling  power,  where  no  central  impulsive  organ 
exists  ;  just  as  a  like  movement  is  seen  in  the  blood-vessels  of  such  of  the  lower  Inverte- 
brata  as  have  no  heart. 


ELABORATING  ACTION  OF  ABSORBENT  SYSTEM.  159 

it  seems  to  be,  that  the  presence  of  fatty  matters  in  the  food  is  essential  to 
healthy  nutrition  (§  57,  in.);  for  no  production  of  fat  by  the  agency  of  tb° 
liver,  can  bring  the  raw  albumen  into  the  same  intimate  relationship  with  the 
minutely-divided  fatty  molecules.  What  other  changes  the  fluid  of  the  Lacteals 
may  undergo,  in  addition  to  the  production  of  fibrin  and  of  corpuscles,  which 
has  been  already  noticed,  and  what  is  the  special  purpose  of  the  elaboration  to 
which  the  fluid  of  the  Lymphatics  is  subjected,  cannot  as  yet  be  distinctly 
stated.  Probably,  however,  the  changes  in  question  are  less  of  a  chemical  than 
of  a  vital  nature,  and  are  such  as  serve  to  prepare  the  fluid  for  maintaining 
the  vital  activity  of  the  several  parts  of  the  organism  to  which  it  is  to  be  dis- 
tributed. 

141.  VASCULAR  or  DUCTLESS  GLANDS.  —  There  is  reason  to  believe  that  a 
similar  office  is  performed  by  certain   bodies  connected  with  the  Sanguiferous 
system,  which  possess  the  essential  elements  of  the  Glandular  structure,  without 
any  efferent  ducts ;  these  must  restore  to  the  circulating  current  any  substances 
which  they  may  withdraw  from  it;  and  there  seems  adequate  ground,  therefore, 
for  the  conclusion,  that  their  action,  whatever  it  may  be,  is  subsidiary  to  the 
completion  of  the  process  of  Sanguification,  —  being  exercised,  perhaps,  upon 
that  portion  of  the  nutrient  materials  more  especially,  which  did  not  traverse 
the  Absorbent  system  when  first  introduced,  but  which  was  directly  taken-up  by 
the  Blood-vessels.     The  organs  in  question  are  the  Spleen,  and  the  Thymus, 
Thyroid,  and  Supra-renal  bodies.     Of  these,  the  Spleen  deserves  especial  notice, 
on  account  of  its  size  and  its  obvious  functional  importance  in  the  adult ;  tho 
others  appearing  to  minister  more  particularly  to  the  requirements  of  the  system 
at  the  earlier  periods  of  life. 

142.  The  minute  structure  of  the  Spleen  has  recently  been  made  the  subject 
of  careful  research  by  many  excellent  Microscopic  observers  :  more  especially  b^ 
Prof.  Kolliker,1  Dr.  Sanders,2  Mr.  Wharton  Jones,3  Mr.  Huxley,4  and  Mr.  Gray ;' 
and,  for  the  lower  Vertebrata  in  particular,  by  Remak,6  and  Leydig.7     The  fol- 
lowing are  the  most  important  points  which  may  be  considered  to  have  been 
established  by  their  labours. 

I.  The  Jibrous  coat  in  Man  is  composed  of  white  fibrous  tissue,  with  an  intei- 
mixture  of  yellow  or  elastic  fibres;  in  many  of  the  lower  animals,  however,  it 
contains  non-striated  muscular  fibres,  composed  of  fusiform  fibre-cells.  The  tra- 
becular  tissue  consists  of  bands  and  threads  of  fibrous  tissue,  which  arise  from 
the  inner  surface  of  the  fibrous  envelope,  and  form  a  network  that  extends  through 
the  entire  organ,  becoming  connected  also  with  the  fibrous  sheaths  of  the  vessels 
which  penetrate  it.  These  bands  are  partly  muscular  in  the  animals  which  have 
muscular  fibres  in  the  external  envelope ;  but  elsewhere  they  are  simply  fibrous. 
The  spaces  left  by  their  intersection,  which  are  by  no  means  regular  as  to  either 
form  or  size,  are  occupied  by  the  splenic  corpuscles  and  splenic  parenchyma. 

n.  Of  the  Arteries  of  the  Spleen,  it  is  chiefly  to  be  observed  that  their  branches 
form  no  anastomoses,  but  subdivide  and  ramify  like  the  branches  of  a  tree,  with 
the  Malpighian  corpuscles  attached  to  them  as  fruit  (Fig.  44).  Beyond  their 

1  "Cyclopaedia  of  Anatomy  and  Physiology,"  vol.  iv.,  Art.  'Spleen;'  and  "  Mikros- 
kopische  Anatomie,"  band  ii.  \\  183-189. 

a  "  Goodsir's  Annals  of  Anatomy  and  Physiology,"  No.  1 ;  and  "Edinb.  Monthly  Jour- 
nal," March,  1852,  p.  286. 

3  "Brit,  and  For.  Med.-Chir.  Review,"  vol.  xi.  p.  32. 

4  "  Quarterly  Journal  of  Microscopical  Science,"  vol.  ii.  p.  74;    and  Translation    of 
Kolliker's  "  Manual  of  Human  Histology"  (Syderiharn  Society),  vol.  ii.  p.  144. 

5  "  The  Structure  and  Use  of  the  Spleen"  (Astley-Cooper-Prize  Essay,  1854). 

8  '  Ueber  runde  Blut-gerinnsel  und  iiber  Pigment-kugelholtige  Zellen,'   in  "Mutter's 
Archiv.,"  1852. 
1  "  Anatomische-Histologische  Untersuchungen  iiber  Fische  und  Reptilien."  1853. 


160 


OF    ABSORPTION    AND    SANGUIFICATION. 


FIG.  44. 


connection  with  these,  however,  they  enter  the  general  mass  of  the  splenic  paren- 
chyma ;  and  here  each  twig  subdivides 
into  a  tuft  of  arterioles  still  more 
minute,  which  again  subdivide  into 
the  true  capillaries. — The  Capillaries, 
bounded  only  by  their  very  thin  walls, 
pass  in  every  direction  through  the 
spleen-pulp,  both  in  the  general  mass 
of  the  organ,  and  also  in  the  interior 
of  the  Malpighian  corpuscles.  But 
it  is  affirmed  by  Mr.  Gray,  that  in 
the  Spleen  of  Man  and  of  many  other 
animals,  the  walls  of  the  capillaries 
frequently  disappear,  and  that  the 
blood,  in  passing  from  the  minutest 
arteries  to  the  minutest  veins,  moves 
in  great  part  through  lacunas,  or 
mere  channels  in  the  pulp-tissue.  — 
Of  the  Veins,  the  idea  has  been  gene- 
rally entertained,  that  they  are  dilated 
into  cavernous  spaces  or  sinuses ;  but 
this,  though  true  of  many  of  the 
lower  Mammalia,  especially  of  rumi- 
nants and  diving  animals,  is  the  case 
to  only  a  very  limited  extent  in  Man. 
Their  mode  of  ramification  closely 


Branch  of  Splenic  Artery,  the  ramifications  of 
which  are  studded  with  Malpighian  corpuscles. 


resembles  that  of  the  arteries ;  and  they  are  unprovided  with  valves. 

ill.  The  Parenchyma  of  the  Spleen  essentially  consists  of  a  homogeneous 
mass  of  colourless  nuclear  corpuscles  and  cells  in  various  stages  of  evolution,  im- 
bedded in  a  granular  plasma;  thus  corresponding  in  every  essential  particular 
with  the  contents  of  the  Peyerian  and  Absorbent  glandulae  (§  133),  and  giving 
evidence,  as  they  do,  of  being  in  a  state  of  rapid  developmental  change.  The 
amount  of  this  colourless  parenchyma  is  stated  by  Mr.  Gray  to  undergo  a  marked 
increase  towards  the  end  of  the  digestive  process,  when  a  large  quantity  of  new 
alimentary  material  is  being  introduced  into  the  sanguiferous  current ;  whilst,  in 
the  intervals  of  this  operation,  it  undergoes  a  gradual  diminution. — The  peculiar 
Splenic  Corpuscles,  or  *  Malpighian  bodies  of  the  Spleen/  are  whitish  spherical 
bodies,  which  are  connected  with  the  smaller  arteries  by  short  peduncles,  like 
grapes  with  their  fruit-stalks,  or  are  sessile  upon  their  sheaths  (Fig.  44).  Their 
diameter  usually  varies  between  l-3rd  and  l-6th  of  a  line ;  smaller  bodies,  how- 
ever, are  met-with,  which  appear  to  be  Malpighian  corpuscles  in  an  earlier  stage 
of  evolution.  The  boundary  of  each  is  an  indistinctly-fibrous  membrane,  which 
appears  to  be  partly  formed  by  the  metamorphosis  of  the  external  cells  of  its 
contained  parenchyma,  and  to  be  partly  derived  from  the  fibrous  coat  of  the  ar- 
tery to  which  it  is  attached.1  And  its  contents  correspond,  in  every  essential 
particular,  with  the  colourless  parenchyma  in  which  they  are  imbedded.  Their 
walls  are  covered  with  a  plexus  of  capillaries,  and  branches  from  these  traverse 
their  interior,  just  as  in  the  case  of  the  Peyerian  and  Absorbent  glandulse.  The 
number  and  size  of  the  Malpighian  corpuscles  bear  a  remarkable  relation  to  the 
general  state  of  nutrition ;  being  much  the  greatest  in  healthy,  well-fed  animals, 
whilst  in  those  that  have  been  ill-fed  they  diminish  extremely,  and  in  those  that 
have  been  starved  they  disappear  altogether.  Hence  it  has  happened  that  their 
existence  in  the  Human  species  has  been  denied ;  the  opportunity  of  examining 

1  It  has  been  commonly  supposed  that  the  Malpighian  corpuscles  are  invested  by  a  dis- 
tinct limitary  membrane,  like  the  acini  of  ordinary  Glands ;  but  such,  from  the  observations 
of  Wharton  Jones  and  Huxley,  would  clearly  seem  to  be  not  the  case. 


VASCULAR   GLANDS:  —  THE   SPLEEN.  1(31 

subjects  not  reduced  by  previous  abstinence,  being  one  that  comparatively  seldom 
occurs.  There  is  no  doubt,  however,  of  their  normal  presence  in  the  spleen  of 
Man,  as  in  that  of  other  Mammalia. — Diffused  amidst  the  colourless  parenchyma, 
but  in  very  variable  amount,  coloured  cells  are  found,  some  of  which  are  un- 
changed blood-corpuscles,  whilst  others  appear  to  be  blood-discs  in  various  stages 
of  retrograde  metamorphosis ;  gradually  diminishing  in  size,  and  assuming  a 
golden-yellow,  brownish-red,  or  even  blackish  colour,  or  having  the  pigmentary 
matter  crystallized  in  a  rod-like  form  in  their  interior  (Fig.  );  or,  again,  break- 
ing-up  into  detached  pigment-granules.  Occasionally  (though  very  rarely  in  the 
Human  subject)  little  clusters  of  these  degenerating  blood-corpuscles  are  found, 
included  in  a  vesicular  envelope.  All  these  bodies  are  seen  in  the  blood  of  the 
Splenic  vein ;  and  it  has  been  hence  concluded  by  some,  that  they  do  not  consti- 
tute normal  elements  of  the  Splenic  parenchyma,  but  that  they  are  either  con- 
tained in  its  capillaries,  or,  if  actually  diffused  through  the  pulp,  are  so  as  a 
result  of  an  abnormal  extravasation.  These  conflicting  views  may  be  reconciled, 
if,  as  stated  by  Mr.  Gray,  the  splenic  blood,  in  its  passage  from  the  arteries  to  the 
veins,  normally  escapes  from  the  walled  vessels  into  indefinite  channels,  so  that 
its  corpuscles  may  become  diffused  through  the  parenchyma  without  any  departure 
from  its  regular  course ;  and  it  is  a  confirmation  of  this  view,  that  the  amount 
of  coloured  corpuscles  in  the  spleen-pulp  augments  with  the  general  turgescence 
of  the  vascular  system,  and  diminishes  with  the  poverty  of  the  blood,  so  that,  in 
animals  reduced  by  ill-feeding,  it  disappears  altogether.1 

IV.  The  Lymphatics  of  the  Spleen  are  few  and  inconsiderable  in  Man ;  being 
less  numerous  than  in  other  glandular  organs,  such  as  the  liver  and  kidneys.     In 
some  of  the  lower  animals,  they  are  more  abundant;   but  even  here  they  are 
mostly  superficial,  and  scarcely  penetrate  to  the  interior  of  the  organ. 

V.  The  Nerves  of  the  Spleen  are  apparently  very  large  in  some  animals,  espe- 
cially in  the  Ruminants ;  but  the  great  size  of  their  trunks  and  branches  is  chiefly 
due  to  the  large  proportion  of  ordinary  fibrous  tissue  which  enters  them  j  the 
number  of  real  nerve-fibres  being  extremely  small.2 

143.  The  history  of  the  development  of  the  Spleen,  which  has  been  recently 
studied  with  much  care  by  Mr.  Gray,3  presents  facts  of  great  interest,  as  aiding 
in  the  determination  of  the  functional  character  of  this  organ,  and  of  the  nature 

1  That  the  coloured  portion  of  the  spleen-pulp  consists  entirely  of  red  blood-corpuscles 
in  various  stages  of  degeneration,  is  a  doctrine  first  advanced  by  Kolliker,  and  confirmed 
more  especially  by  Gray.    On  the  other  hand,  it  is  maintained  by  Remak  that  the  coloured 
corpuscles  are  true  pigment-cells,  having  no  relation  to  blood-discs,  but  altogether  sui 
generis.     The  extended  enquiries  of  Mr.  Gray,  who  has  traced  the  metamofphic  process  in 
a  great  variety  of  animals,  seem  to  the  Author  to  leave  little  doubt  of  the  correctness  of 
the  former  view,  though  proper  pigment-cells  may  also  exist :  and  it  is  an  interesting  con- 
firmation of  Mr.  G.'s  account  of  the  mode  of  derivation  of  the  coloured  elements  from  the 
blood  circulating  through  the  spleen-pulp,  that  in  those  animals  in  which  he  finds  the  capil- 
lary network  in  the  substance  of  the  spleen  to  be  closed  throughout,  there  are  no  coloured 
corpuscles  in  the  parenchyma. 

2  A  comprehensive  view  of  the  essential  nature  of  the  Spleen,  based  upon  the  varieties 
of  structure  which  it  presents  in  different  animals,  shows  that,  as  Remak  urges,  we  should 
regard  it  as  formed  of  two  principal  constituents ;  the  first  being  its  parenchymatous  sub- 
stance, composed  of  a  granular  blastema  containing  nuclei  and  cells  in  various  stages  of 
development;  whilst  the  second  is  a  superadded  fabric  of  blood-vessels,  nerves,  lymphatics, 
and  fibrous  (elastic  or  non-elastic)  tissue.     The  manner,  however,  in  which  the  latter  are 
arranged  in  and  about  the  parenchyma,  is  in  a  manner  accidental ;  and  varies  considerably 
in  different  animals.     The  parenchymatous  substance  may  be  intercapiUary,  as  in  the  ordi- 
nary spleen-pulp ;  or  it  may  be  specially  limited  to  the  medullary  portion  of  the  organ,  as 
in  certain  Amphibia  ;  it  may  be  vaginal,  that  is,  dispersed  through  the  coats  of  the  arteries, 
as  in  some  Fishes ;  or  it  may  be  encysted,  as  in  the  most  characteristic  forms  of  Malpighian 
corpuscles,  which  are  still  to  be  regarded,  however,  as  offsets  from  the  walls  of  the  blood- 
vessels. 

s  "On  the  Development  of  the  Ductless  Glands  in  the  Chick,"  in  "Philosophical  Trans- 
actions," 1852,  p.  295;  see  also  his  Prize  Essay. 
11 


162  OF    ABSORPTION    AND    SANGUIFICATION. 

of  its  component  parts. — It  arises  in  the  Chick  between  the  4th  and  5th  days  of 
incubation,  in  the  fold  of  membrane  which  connects  the  intestinal  canal  to  the 
spine  (the  'intestinal  lamina'),  as  a  small  whitish  mass  of  blastema,  perfectly 
distinct  from  both  the  stomach  and  the  pancreas;  from  the  former  of  which  it  has 
been  said  by  Bischoff,  and  from  the  latter  by  Arnold,  to  take  its  origin.  The 
external  capsule  and  the  trabecular  tissues  are  developed  between  the  8th  and  9th 
days  :  the  former  as  a  thin  membrane  composed  of  nucleated  fibres ;  the  latter 
consisting  of  similar  fibres,  which  intersect  the  organ  at  first  sparingly,  and  after- 
wards in  greater  quantity.  The  blood-vessels  of  this  organ  are  formed  within 
itself,  independently  of  those  which  are  exterior  to  it ;  and  blood-corpuscles  are 
also  observed  to  originate  in  the  substance  of  its  blastema,  their  formation  continu- 
ing until  its  connection  with  the  general  vascular  system  is  completed,  at  which 
period  their  development  appears  to  cease. — The  pulp-tissue,  at  an  early  period  of 
its  formation,  closely  corresponds  with  that  of  the  supra-renal  and  thyroid  bodies 
in  their  earliest  stages  of  evolution ;  consisting  of  nuclei,  nucleated  vesicles,  and  a 
fine  granular  plasma.  When  the  splenic  vessels  are  being  formed,  many  of  those 
nuclei  are  surrounded  by  a  quantity  of  fine  dark  granules,  arranged  in  a  circular 
mode ;  and  these  appear  to  be  developed  into  nucleated  vesicles,  of  which,  when 
the  splenic  vein  is  formed,  nearly  the  whole  pulp  is  composed ;  the  nuclei  of 
these  subsequently  break-up  into  a  mass  of  granules,  which  fill  the  cavities  of  the 
vesicles.  The  Malpighian  corpuscles  are  developed  in  the  pulp,  at  the  angles  of 
division  of  the  smaller  blood-vessels,  by  the  aggregation  of  nuclei  into  circular 
masses,  around  which  a  fine  membrane  is  subsequently  formed. — Thus  during 
foetal  life  we  have  evidence  of  a  process  of  cell-growth  and  maturation,  followed 
by  cell-destruction,  in  the  colourless  parenchyma.  There  is  no  evidence  of  the 
formation  of  blood-discs  in  this  organ,  after  its  connection  with  the  general 
vascular  system  has  been  effected ;  nor  is  there  any  appearance  of  the  disintegra- 
tion of  blood-discs  during  foetal  life.  The  largest  proportional  size  and  the  greatest 
functional  activity  of  the  Spleen,  however,  seem  to  be  exhibited  during  adolescence 
and  the  most  vigorous  period  of  adult  life. 

144.  The  Supra-Renal  bodies  in  Man  and  most  Mammalia,  present,  like  the 
Kidneys,  a  division  into  cortical  and  medullary  substances ;  the  former  having  a 
lighter  hue  than  the  latter. — The  cortical  substance  is  principally  formed  of  a 
stroina  of  connective  tissue,  so  arranged  as  to  leave  a  series  of  oval  spaces,  lying 
end  to  end;1  which  spaces  are  filled  with  a  finely-granular  plasma,  containing  a 
large  amount  of  fat  particles,  with  nuclear  corpuscles,  and  more  or  less  completely 
formed  cells.  Isolated  cells  of  a  larger  size  are  found  in  the  stroma  of  the  inner 
part  of  the  cortex,  in  which  the  linearly-arranged  spaces  do  not  exist. — The 
medullary  substance  consists  of  a  basis  of  fibrous  tissue,  which  is  formed  by  pro- 
cesses that  come-off  from  the  sheath  of  the  cortical  substance,  and  which  contains 
numerous  blood-vessels  and  nerves.  The  interspaces  of  this  tissue,  -however,  are 
occupied  by  a  granular  plasma,  in  which  are  nuclei  and  cells  in  various  stages  of 
development ;  and  the  recent  observations  of  Kolliker  upon  the  nature  of  these 
cells,  which  are  confirmed  by  the  researches  of  Leydig  (Op.  cit.)  upon  the  cor- 
responding organs  in  the  Amphibia,  seem  to  indicate  that  they  are  really  ganglionic 
in  their  character.  It  has  been  previously  remarked  that  the  Medullary  substance 
receives  a  peculiarly  large  supply  of  nerves  from  the  Sympathetic  system;  and  it 
Urns  appears  as  if  this  portion  of  the  organ  is  but  little  or  not  at  all  related  in 
function  to  that  which  invests  it,  but  is  really  a  peculiar  Sympathetic  ganglion.2 
Both  the  cortical  and  the  medullary  substances  receive  a  large  supply  of  blood, 

1  This  is  the  account  given  by  Kolliker  ("  Mikroskopische  Anatomic,"  \  220),  who  con- 
fidently  states  that  the  spaces  are  not  bounded  by  a  proper  limitary  membrane,  and  are 
therefore  not  gland-vesicles  as  supposed  by  Ecker  and  Frey,  whose  views  of  their  nature 
will  be  found  in  the  Art.  '  Supra-Renal  Capsules'  in  the  "  Cyclop,  of  Anat.  and  Physiol.," 
vol.  iv. 

1  A  curious  observation,  strikingly  confirmatory  of  this  view  of  the  peculiar  relation  of 
the  Medullary  substance  of  the  Nervous  System,  has  been  recently  made  by  M.  Brown- 


VASCULAR  GLANDS: — THYMUS   GLAND. 


163 


which  is  distributed  through  a  minutely-divided  capillary  plexus;  its  meshes 
being  elongated  in  the  former,  and  more  rounded  in  the  latter. 

145.  The  development  of  the  Supra-Renal  bodies  also  has  been  studied  by  Mr. 
Gray  (loc.  cit).     He  states  that  they  arise  on  the  7th  day  of  incubation,  as  two 
separate  masses  of  blastema,  situated  between  the  upper  end  of  the  Wolffian 
bodies  and  the  sides  of  the  aorta;  being  totally  independent  (as  concerns  their 
development)  of  those  bodies  and  of  each  other.     At  this  period,  their  minute 
structure  bears  a  close  resemblance  to  that  of  the  spleen,  consisting  of  the  same 
elements  as  that  gland,  excepting  in  the  existence  of  more  numerous  dark  granules, 
which  give  to  the  organ  at  a  later  period  an  opake  and  darkly-granular  texture ; 
and  the  general  history  follows  a  very  similar  course ;  the  Supra-renal  capsules, 
however,  acquiring  their  characteristic  structure,  and  attaining  their  largest  rela- 
tive size,  so  early  in  foetal  life,  as  to  surpass  the  Kidneys  in  dimension  up  to  the 
tenth  or  twelfth  week  of  Human  embryonic  development;    though  they  after- 
wards diminish  so  much,  relatively  to  the  Kidneys,  as  to  possess  in  the  adult 
condition  only  l-28th  part  of  their  bulk. 

146.  The  general  structure  of  the   Thymus  Gland  may  be  best  understood 
from  the  simple  form  it  presents,  when  it  is  first  capable  of  being  distinguished 
in  the  embryo.     It  then  consists  of  a  single  tube,  closed  at  both  ends,  and  filled 
with  granular  matter;    and  its  subse- 
quent development  consists  in  the  lat-  TFia.  45. 

eral  growth  of  branching  off-shots  from 
this  central  tubular  axis.  In  its  mature 
state,  therefore,  it  consists  of  an  assem- 
blage of  hollow  glandular  lobules  united 
together  by  connective  tissue  (Fig.  45)  ; 
and  their  cavities  all  communicate  with 
the  central  reservoir,  from  which,  how- 
ever, there  is  no  outlet  (Figs.  46,  47). 
Each  lobule  is  bounded  externally  by  an 
indistinctly-fibrous  or  almost  homogene- 
ous membrane  (Fig.  48,  a),  which 
sends  prolongations  (6)  into  its  sub- 
stance, that  divide  it  into  'acini'  or 
gland-granules.  Isolated  gland-gran- 
ules of  the  same  kind  are  frequently  to  A  section  of  the  Thymus  gland  at  the  eighth 
be  inet-with  on  the  main  canal  (Fiff.  month,  showing  its  anatomy;  from  a  preparation 
46,  c).  The  parenchyma  of  each  lobule  0!"  Sl'r  A.  Cooper's;  1,  the  cervical  portions  of  the 
rj  J  .  ,  ,  .  -  gland;  the  independence  of  the  two  lateral  glands 

IS  made-up  Ot  a  greyish-white,  SOtt,  iswell  marked;  2,  secretory  follicles.seen  upon  the 
easily  lacerable  substance,  which,  when  surface  of  the  section ;  these  are  observed  in  all 
examined  microscopically,  is  found  to  parts  of  the  section;  3,  3,  the  pores  or  openings  of 
consist  of  free  nuclei  and  minute  cells  ;  the  secretory  follicles  and  pouches  ;  they  are  seen 
and  it  is  traversed  by  a  minutely-dis-  covering  the  whole  internal  surface  of  the  great 

J  central  cavity  or  reservoir.     The  continuity  of  the 

tributed  capillary  plexus;  thus  resem-  reservoir  In  the  lower  or  thoracic  portion  of  the 
bling  in  every  respect,  save  the  presence  gland  with  the  cervical  portion  is  seen  in  the  figure. 

of  a  central  cavity,  that  of  the  Peyerian 

bodies  (§  133). *  Cells  and  nuclei  resembling  those  of  the  parenchyma  are  also 
found  in  the  cavity  of  the  lobule ;  from  which  indeed  the  parenchyma  is  not  sepa- 
rated by  any  distinct  limitary  membrane.  Their  chemical  composition  corresponds 
with  that  of  the  ordinary  protein-compounds. — The  Vascular  supply  of  this  organ, 
during  the  period  of  its  functional  activity,  is  extremely  abundant.  The  arterial 

Se"quard ;  viz.,  that  injuries  to  the  Spinal  Cord  in  the  dorsal  region,  produce  congestion 
and  (after  a  time)  hypertrophy  of  the  Supra-Renal  capsules  ("Gazette  Me"dicale,"  Febr.  1, 
1852. 

1  See  Prof.  Kolliker's  "  Mikroskopische  Anatomic,"  \  208,  from  which  the  above  account 
is  chiefly  derived;  also  Mr.  Simon's  "Physiological  Essay  on  the  Thymus  Gland." 


164 


OF    ABSORPTION    AND     SANGUIFICATION. 


trunks  penetrate  to  its  central  cavity,  and  form  a  close  reticulation  in  the  delicate 
pellicule  of  connective  tissue  with  which  it  is  lined ;  from  the  several  points  at 
which  the  lobular  cavities  open,  numerous  vessels  arise  from  this  plexus  (Fig  48), 
passing  along  their  internal  surface  j  and  from  these  is  derived  the  capillary  plexus 
which  traverses  the  substance  of  each  gland-granule,  but  which  does  not  pass  as 
far  as  its  external  surface,  returning  by  loops  before  it  reaches  its  fibrous  envelope. 
The  Lymphatics  of  the  Thymus  are  large,  and  communicate  directly  with  the 
Vena  Cava ;  but  their  immediate  connection  with  the  cavity  of  the  Thymus  body 
has  not  been  demonstrated.  It  has  been  commonly  stated,  that  the  Thymus 
attains  its  greatest  development,  in  relation  to  the  rest  of  the  body,  during  the 
latter  part  of  foetal  life ;  and  it  has  been  considered  as  an  organ  peculiarly  con- 
nected with  the  embryonic  condition.  But  this  is  a  mistake ;  for  the  greatest 
activity  in  the  growth  of  this  organ  manifests  itself,  in  the  Human  infant,  soon 
after  birth;  and  it  is  then,  too,  that  its  functional  energy  seems  the  highest. 
This  rapid  state  of  growth,  however  soon  subsides  into  one  of  less  activity,  which 


FIG.  46. 


Fio.  47. 


Portion  of  Thymus  of  Calf,  un- 
folded ;  o,  main  canal ;  ft,  glandula/ 
lobules  ;  c,  isolated  gland-granules 
seated  on  the  main  canal. 


Section  of  Human  Thymus,  showing 
the  large  cavity  in  the  wide  portion 
and  numerous  orifices  leading  to  its 
lohular  cavities. 


merely  serves  to  keep-up  its  proportion  to  the  rest  of  the  body ;  and  its  increase 
usually  ceases  altogether  at  the  age  of  about  two  years.  From  that  time,  during 
a  variable  number  of  years  it  remains  stationary  in  point  of  size  ;  but,  if  the  indi- 
vidual be  adequately  nourished,  it  gradually  assumes  the  character  of  a  mass  of 
fat,  by  the  development  of  the  corpuscles  of  its  interior  into  fat-cells,  which 
secrete  adipose  matter  for  the  blood.  This  change  in  its  function  is  most  remark- 
able in  hybernating  Mammals ;  in  which  the  development  of  the  organ  continues, 
even  in  an  increasing  ratio,  until  the  animal  reaches  adult  age,  when  it  includes  a 
large  quantity  of  fatty  matter.  The  same  is  the  case,  generally  speaking,  among 
Reptiles. 


VASCULAR     GLANDS  ; — T  HYROID     BODY. 


165 


147.  The  Thyroid  body  differs  from  the  other  Vascular  Glands  in  its  elemen- 
tary structure;  for  it  essentially  consists  of  an  aggregation  of  closed  vesicles 
(Fig.  49,  b,  6),  which  seem  to  be  furnished  with  a  true  limitary  membrane,  and 
therefore  to  be  real  gland-vesicles,  imbedded  in  a  stroma  (a,  a)  of  connective  tissue, 
and  not  communicating  with  any  common  reservoir.  These  bodies  vary  in  diameter, 
in  the  Human  subject,  from  l-2000th  to  l-85th  of  an  inch;  and  they  contain  an 
albuminoid  plasma,1  which  is  either  faintly  granular,  or  of  a  somewhat  oily  aspect, 


FIG.  48. 


FIG.  49. 


Transverse  section  through  an  injected 
lobule  of  the  Thymua  in  a  child  ; — a,  mem- 
branous investment  of  the  lobule  ;  b,  mem- 
brane of  the  gland-granules ;  c,  cavity  of 
the  lobule,  from  which  the  larger  vessels 
branch-out. 


Group  of  gland  vesicles  from  the  Thyroid  Gland 
of  a  child  j  a,  connective  tissue ;  b,  membrane  of 
the  vesicles  ;  c,  epithelial  cells. 


amidst  which  are  seen  a  number  of  corpuscles,  the  greater  part  of  them  in  the 
condition  of  nuclei,  whilst  some  have  advanced  to  that  of  cells.  These  corpuscles, 
however,  seem  rather  to  occupy  the  position  of  an  epithelium  (c,  c)  within  the 
vesicles,  than  to  float  freely  in  their  contained  fluid. — The  vascular  supply  of  the 
Thyroid  body  is  extremely  abundant;  and,  as  in  preceding  instances,  the  sub- 
divisions of  its  arteries  form  a  very  minute  capillary  plexus  upon  the  membrane 
of  the  vesicles.  No  Lymphatics  have  been  traced  far  into  its  substance. — The 
development  of  the  Thyroid  body  has  been  shown  by  Mr.  Gray  (loc.  cit.)  to  be 
closely  accordant  with  that  of  the  '  ductless  glands'  already  described.  This  body 
originates  in  two  separated  masses  of  blastema,  one  at  each  side  of  the  root  of  the 
neck,  close  to  the  separation  of  the  carotid  and  subclavian  vessels,  and  between 
the  trachea  and  the  branchial  clefts,  but  quite  independent,  as  far  as  regards  their 
development,  of  either  of  those  parts ;  their  minute  structure  at  an  early  period 
closely  corresponds  with  that  of  the  spleen  and  supra-renal  glands.  This  body, 
like  the  Supra-renal  and  Thymus,  is  of  larger  relative  magnitude  during  iutra 
uterine  existence  and  infancy,  than  in  after-life. 

148.  That  the  Ductless  or  Vascular  Glands,1  of  whose  peculiar  structure  and 

1  That  the  fluid  does  not  contain  true  Albumen  in  solution,  but  some  albuminous  com- 
pounds, is  indicated  by  the  results  of  Dr.  Beale's  analysis  ("  Cyclop,  of  Anat.  and  Physiol.," 
vol.  iv.  p.  1106). 

1  According  to  Ecker,  (Art.  ' Blutgefassdrusen'  in  "Wagner's  Handworterbuch,"  band 
iv.),  the  Pituitary  body  has  the  same  essential  structure  as  the  vascular  glands  in  general; 


166  OF    ABSORPTION    AND    SANGUIFICATION. 

relations  we  have  thus  taken  a  general  survey,  have  some  office  of  importance  to 
perform  in  the  preparation  and  maintenance  of  the  Blood;  cannot  any  longer  be 
reasonably  questioned ;  and  the  determination  of  this  point  may  be  fairly  re- 
garded as  a  considerable  step  in  the  investigation.  It  is  obvious,  from  the  very 
copious  supply  of  blood  which  they  receive  during  the  period  of  their  functional 
vigour,  and  from  the  manner  in  which  this  is  distributed  by  minute  capillary 
plexuses,  on  the  exterior,  and  even  through  the  interior,  of  the  glandular  vesicles, 
that  it  must  be  subservient  to  some  process  of  active  change ;  and  the  aspect  of 
the  contents  of  these  vesicles,  as  well  as  of  the  substance,  in  which  they  are  im- 
bedded, indicates  that  cell-growth  is  rapidly  proceeding,  at  the  expense  of  the 
materials  thus  afforded.  But,  on  the  other  hand,  that  the  products  of  this  cell- 
growth  are  not  substances,  which,  like  those  of  the  ordinary  glands,  must  be 
separated  from  the  Blood,  either  for  its  purification,  or  to  serve  some  special  pur- 
pose in  the  economy,  appears  from  the  fact  that  they  are  not  carried-off  by  ducts, 
but  are  received  again  into  the  current  of  the  circulation.  With  the  exception 
of  the  Spleen,  all  the  ductless  glands  thus  discharge  their  products  at  once  into 
the  general  venous  circulation;  so  that,  after  having  passed  through  the  lungs, 
they  will  be  carried  by  the  systemic  arteries  through  the  system  at  large ;  but 
the  splenic  vein,  it  will  be  remembered,  forms  one  of  the  roots  of  the  portal 
trunk ;  and  its  blood  must  thus  pass  through  the  liver,  before  it  enters  the  vena 
cava.  For  this  exception,  a  reason  may  probably  be  found  in  the  peculiar  offices 
which  this  organ  seems  to  perform  (§  151). 

149.  Whatever  materials,  then,  are  withdrawn  from  the  Blood  by  these  organs, 
are  returned  to  it  again  in  an  altered  state;  and  it  may  fairly  be  inferred  from 
this  circumstance,  that  the  change  which  they  have  undergone  is  one  that  pre- 
pares them  for  higher  uses  in  the  economy.  For  as  the  blood  which  has  received 
them  is  immediately  transmitted  to  the  system  (except  in  the  case  of  the  splenic 
blood),  without  having  passed  through  any  other  depurating  organ  than  the 
lungs,  it  appears  fair  to  conclude  that  the  products  which  it  has  taken-up  in  these 
organs  are  either  comLustive  or  nutritive  j  i.  e.,  either  serve  to  maintain  the 
functional  activity  of  the  lungs,  or  of  the  system,  or  of  the  blood  itself.  Now 
that  they  are  not  destined  to  prepare  a  pabulum  for  respiration,  appears  from  the 
very  small  quantity  of  fat  which  is  found  in  their  substance,  except  when  their 
period  of  functional  activity  has  gone-by.  On  the  other  hand,  the  albuminous 
nature  of  the  plasma,  and  the  finely-granular  appearance  which  it  presents, 
strongly  indicate  that  a  material  is  here  in  progress  of  preparation,  which  is  to 
be  rendered  subservient  to  the  formative  operations.  Various  facts  which  have 
been  noticed  in  regard  to  the  changes  in  the  bulk  of  the  Thymus  in  young  ani- 
mals (and  particularly  its  rapid  diminution  in  over-driven  lambs,  and  its  subse- 
quent gradual  re-distension  during  rest,  if  plentiful  nutriment  be  afforded),  lead 
to  the  conclusion  that  such  is  almost  undoubtedly  the  function  of  that  body. 
And  such  would  also  seem  to  be  the  justifiable  inference  from  the  researches  of 
Mr.  Gray  on  the  Spleen :  for  the  correspondence  in  the  amount  of  the  colourless 
parenchyma  of  that  organ  (and  especially  of  its  Malpighian  corpuscles)  with  the 
general  state  of  nutrition  of  the  animal,  its  regular  increase  (in  well-fed  animals) 
near  the  completion  of  the  digestive  process,  and  its  gradual  diminution  in  the 
subsequent  interval,  seem  to  indicate  that  the  Spleen,  like  the  Thymus  of  the 
young  animal,  is  a  storehouse  of  nutritive  material,  which  may  be  drawn-upon 
according  to  the  requirements  of  the  system,  just  as  the  fat  of  the  body  is  a 
storehouse  of  combustive  substance.  And  of  the  exertion  of  an  elaborating  or 
assimilative  action  upon  this  albuminous  matter,  during  its  withdrawal  from  the 
current  of  the  circulation  in  these  organs,  we  seem  to  have  direct  evidence,  as 
regards  the  Spleen,  in  the  large  increase  of  the  proportion  of  fibrin  contained  in 
the  blood  drawn  from  its  veins  (§  184). 

having  vesicles  containing  a  finely-granular  blastema,  with  nuclear  particles,  imbedded  in 
»»  fibrous  stroma. 


FUNCTION    OF    THE    VASCULAR    GLANDS.  167 

150.  But  further,  it  does  not  seem  at  all  unreasonable  to  suppose  that  these 
organs  may  be  concerned,  equally  with  the  Absorbent  glands,  in  supplying  the 
germs  of  those  cells  which  are  ultimately  to  become  Blood-corpuscles.  *Such,  it 
is  well  known,  was  the  doctrine  of  Hewson1  in  regard  to  the  Spleen  and  Thymus 
gland ;  and  there  are  many  facts  which  lend  it  a  considerable  probability  In 
the  first  place,  we  have  seen  (§  142,  11.)  that  there  is  no  difficulty  whatever  in 
the  admission  of  such  corpuscles  into  the  smaller  veins  of  the  Spleen,  if  Mr. 
Gray's  account  of  its  lacunar  circulation  be  correct;  and  that  there  is  no  physical 
impossibility  in  the  reception  of  particles  of  such  a  size  into  the  interior  of  even 
a  closed  system  of  capillaries,  is  proved  by  the  very  curious  facts  already  noticed 
in  regard  to  the  passage  of  starch-grains  into  the  mesenteric  veins  (§  125). 
Secondly,  there  is  an  unusual  proportion  of  colourless  corpuscles  in  the  blood  of 
the  splenic  vein.2  Thirdly,  the  period  of  greatest  functional  activity  of  these 
glands  generally,  is  during  the  state  of  early  childhood,  when  the  formative  pro- 
cesses are  going-on  with  extraordinary  activity ;  and  there  is  at  this  time  a  larger 
proportion  of  colourless  corpuscles  in  the  blood,  than  at  any  subsequent  period, 
at  least  in  the  healthy  state.  Further,  as  Prof.  J.  H.  Bennett  has  pointed-out, 
that  peculiar  condition  of  the  blood,  which  consists  m  the  multiplication  of  its 
colourless  corpuscles  (§  191),  is  almost  always  associated  with  hypertrophy  of  one 
of  these  bodies ;  and  in  one  case  of  this  kind,  in  which  the  Thyroid  was  the 
organ  affected,  its  cells  and  their  included  nuclei  were  observed  to  be  consider- 
ably smaller  than  usual,  and  the  same  peculiarity  presented  itself  in  the  colour- 
less corpuscles  of  the  blood.3  Hence  there  seems  a  strong  probability,  that 
whilst  the  plasma  of  the  blood  is  being  elaborated  by  these  bodies,  a  constant 
supply  of  new  blood-corpuscles  is  also  afforded  by  them  j 4  and  that  they  thus 
effect  that  for  the  nutrient  materials  directly  absorbed  into  the  Sanguiferous 
system,  which  the  glandulee  in  connection  with  the  Absorbent  system  accomplish 
for  the  substances  which  it  has  taken-up. 

151.  The  peculiar  position  of  the  Spleen,  however,  in  reference  to  the  Portal 
circulation,  seems  to  mark  it  out  as  having  some  special  function  of  a  supple- 
mental character.  Two  out  of  the  many  theories  of  its  action  which  have  been 
advanced,  deserve  particular  notice  in  connection  with  this  point.  Many  experi- 
menters have  come  to  the  conclusion,  that,  whatever  may  be  the  other  purposes 
answered  by  the  Spleen,  it  serves  as  a  diverticulum  to  the  Portal  circulation,  so 
as  to  relieve  its  vessels  from  undue  turgescence,  in  virtue  of  the  readiness  with 
which  it  is  distended  with  blood ;  and  this  under  a  great  variety  of  circumstan- 
ces. As  the  portal  system  is  destitute  of  valves,  the  splenic  vein  has  free  com- 
munication with  the  whole  of  it ;  and  thus  the  Spleen  will  serve  as  a  receptacle 
for  the  venous  blood,  when  the  secreting  action  of  the  Liver  is  feeble,  so  that 
the  portal  circulation  receives  a  partial  check.  That  any  cause  of  obstruction- to 
the  hepatic  circulation  peculiarly  affects  the  Spleen,  has  been  proved  by  experi- 
ment; for  after  the  Vena  Portse  has  been  tied,  the  spleen  of  an  animal,  which 
previously  weighed  only  2  oz.,  has  been  found  to  weigh  a  pound  and  a  quarter, 
or  ten  times  as  much.  Further,  it  is  evident  that  turgescence  of  the  portal 
system  is  liable  to  occur,  when  the  alimentary  canal  is  distended  with  food  :  and 
this  from  two  causes, — the  pressure  on  the  intestinal  veins,  and  the  quantity  of 
fluid  absorbed  by  these  veins.  Hence  it  may  be  conceived,  that  the  Spleen,  by 
affording  a  reservoir  into  which  the  superfluous  blood  may  be  directed,  serves  an 

1  See  his  Third  Series  of  "Experimental  Inquiries,"  Chaps,  iii.  v. 

a  See  Funke  in  "  Henle's  Zeitschrift,"  1851,  p.  172,  and  Gray,  Op.  cit.,  p.  148. 

3  This  fact  is   the  more  weighty,  as,  in  another  case   observed  by  Prof.  Bennett,  the 
colourless  corpuscles  of  the  blood  were  of  two  distinct  sizes,  the  smaller  corresponding 
with  the  nuclei  of  the  larger  ones ;  and  the  lymphatic  glands  were  found  to  be  crowded 
with  corpuscles  also  of  two  distinct  sizes,  exactly  corresponding  with  those  of  the  blood. 
(See  "Edinb.  Monthly  Journal,"  October,  1851.) 

4  This  view  has  been  ably  supported  by  Prof.  J.  H.  Bennett,  in  "  Edinb.  Monthly  Journ  ," 
March,  1852;  and  in  his  Treatise  ou  "  Leucocythsoniia." 


168  OF    ABSORPTION    AND    SANGUIFICATION. 

important  purpose  in  preventing  congestion  of  other  organs.  From  the  obser- 
vations of  Mr.  Dobson,1  it  appears  that  the  Spleen  has  its  maximum  volume  at 
the  time  when  the  process  of  chymification  is  at  an  end., —  namely,  about  fivei 
hours  after  food  is  taken ;  and  that  it  is  small  and  contains  little  blood  seven 
hours  later,  when  no  food  has  been  taken  in  the  interval.  Hence  he  inferred 
that  this  organ  is  the  receptacle  for  the  increased  quantity  of  blood,  which  the 
system  acquires  from  the  food,  and  which  cannot,  without  danger,  be  admitted 
into  the  blood-vessels  generally;  and  that  it  regains  its  previous  dimensions,  after 
the  volume  of  the  circulating  fluid  has  been  reduced  by  secretion.  This  view  is 
confirmed  by  the  fact  noticed  by  several  observers, — that  the  Spleen  rapidly  in- 
creases in  bulk  after  the  ingestion  of  a  large  quantity  of  fluid,  which  is  absorbed 
rather  by  the  Veins  than  by  the  Lacteals.  It  has  been  further  stated  in  support 
of  this  theory,  that  animals  from  which  the  Spleen  has  been  removed,  are  very 
liable  to  die  of  apoplexy,  if  they  take  a  large  quantity  of  food  at  a  time ;  but 
that,  if  they  eat  moderately  and  frequently,  they  do  not  suffer  in  this  manner. — 
Now  this  doctrine  derives  its  chief  support  from  experiments  on  Ruminating  and 
other  Herbivorous  animals,  whose  food  is  very  bulky,  and  who  ingest  a  large 
quantity  of  it  at  a  time;  and  it  is  in  them  that  the  organ  is  most  distensible, 
and  that  the  splenic  vein  is  best  adapted,  by  the  peculiar  disposition  of  its  coats, 
for  the  reception  of  a  very  large  amount  of  blood.  The  celldted  structure  which 
forms  a  large  part  of  the  spleen  in  these  tribes,  is  almost  wanting  in  Man  (§  142, 
II.);  and  the  fibrous  envelope  of  his  spleen,  with  its  trabecular  partitions,  has 
very  little  either  of  elasticity  or  contractility.  Nevertheless,  there  is  evidence 
that  an  extraordinary  accumulation  of  blood  may  take  place  in  this  organ,  even 
in  him,  from  any  cause  which  obstructs  the  passage  of  blood  through  the  liver, 
or  which  impedes  its  return  to  the  heart  (as  in  Asphyxia,  §  327),  or  which  occa- 
sions a  general  internal  venous  congestion,  such  as  occurs  in  the  cold  stage  of 
intermittent  fever.  The  peculiar  liability  of  the  Spleen  to  be  distended  with 
blood  in  this  last  condition,  is  shown  by  its  permanent  enlargement  in  those  who 
have  been  long  the  subjects  of  such  complaints. — Thus  it  appears  that  the  Spleen 
may  serve,  independently  of  its  primary  function,  as  a  sort  of  safety-valve  to  the 
portal  circulation ;  and  that  its  structure  is  most  particularly  adapted  for  such  a 
purpose  in  those  tribes  of  animals,  which,  from  their  habits  of  feeding,  may  be 
considered  most  specially  to  need  an  organization  of  this  kind. 

152.  There  is  strong  evidence,  moreover,  that  the  Spleen  of  Man,  as  of  a 
large  proportion  of  Vertebrated  animals,  performs  another  function  connected 
with  the  regulation  of  the  composition  of  the  Blood;  namely,  that  it  promotes, 
under  certain  circumstances,  the  disintegration  of  the  Red  Corpuscles.  If  it  be 
true  that  the  coloured  portion  of  the  pulp  consists  entirely  (as  affirmed  by  Kolli- 
ker  and  Gray)  of  red-blood  corpuscles  in  various  stages  of  degeneration,  which 
have  escaped  from  the  channels  that  take  the  place  of  true  capillaries  (§  142, 
II.,  in.),  such  would  unquestionably  seem  to  be  a  part  of  its  duty.  And  this 
view  is  corroborated  by  the  results  of  chemical  analysis  of  the  blood  returning 
from  the  Splenic  vein,  or  drawn  from  the  interior  of  the  organ  itself  (§  184). 
It  seems  to  be  only,  however,  when  a  certain  amount  of  vascular  turgescence  is 
induced  by  an  approach  to  the  state  of  plethora,  that  this  extravasation  occurs, 
and  that  the  disintegrating  operation  is  performed ;  since  the  diminution  in  the 
amount  of  red  corpuscles  in  the  emerging  blood  of  the  spleen,  is  not  only  by  far ' 
the  greatest  in  the  best-fed  animals,  but  does  not  manifest  itself  at  all  in  such  as  , 
have  been  starved,  in  which  also  the  coloured  pulp  of  the  spleen  almost  dis- 
appears.2 

*      London  Medical  and  Physical  Journal,"  October,  1820. 

3  See  Gray  "On  the  Structure  and  Use  of  the  Spleen  ;"  also  a  Review  of  that  work  in 
the  "Brit,  and  For.  Med.-Chir.  Rev."  Jan.  1855. — By  Prof.  Kolliker  it  was  supposed  that 
the  disintegration  of  the  blood-discs  had  reference  especially  to  the  preparation  of  biJe- 
pigment  at  the  expense  of  haematin ;  but  this  doctrine  is  negatived  by  a  variety  of  c<m. 


OF    THE    BLOOD. — GENERAL    CONSIDERATIONS.        169 


CHAPTER  V. 

OF    THE   BLOOD ;    ITS  PHYSICAL  CHARACTERS,  ITS    CHEMICAL  COMPOSITION,  AND 
ITS    VITAL   PROPERTIES. 

1.    General  Considerations: — Quantity  of  Blood. 

153.  FROM  the  materials  supplied  in  the  Food,  there  is  prepared,  by  the 
Digestive  and  Assimilative  processes  described  in  the  preceding  Chapters,  that 
general  nutritive  liquid,  the  Hlood,  which,  in  the  organism  of  Man  (as  in  that 
of  all  the  higher  Animals)  is  constantly  circulating  through  its  vessels  during 
the  whole  of  life.  From  this  liquid,  each  portion  of  the  solid  tissues  has  the 
power  of  extracting,  and  appropriating  to  its  own  use,  the  particular  components 
of  its  substances  ;  these  either  pre-existing  as  such  in  the  blood,  or  being  capable 
of  being  readily  formed  from  it  by  a  process  of  chemical  transformation. 
During  its  circulation,  moreover,  the  blood  draws  into  its  current  the  eifete  par- 
ticles which  are  set-free  by  the  disintegration  of  the  tissues  (probably  at  the  very 
time  when  it  gives-forth  the  components  of  the  newly-forming  structures),  and 
conveys  them  to  the  various  organs  which  are  provided  for  their  elimination. 
Hence  the  Blood  not  only  contains  the  materials  for  the  renovation  of  the  tis- 
sues, but  also  the  products  of  their  decay :  but  there  is  an  important  difference 
in  the  proportion  of  these  two  sets  of  components;  for  whilst  the  former  make- 
up the  principal  part  of  the  mass  of  the  fluid,  the  latter  are  only  detectable  in  it 
with  difficulty,  so  long  as  the  excretory  organs  maintain  their  normal  activity; 
and  only  make  their  presence  obvious,  when  they  accumulate  unduly,  in  conse- 
quence of  the  retardation  or  suspension  of  the  eliminating  operations.  —  But 
besides  thus  meeting  the  demand  occasioned  by  the  constructive  operations,  and 
preventing  the  results  of  the  destructive  from  exerting  an  injurious  influence  on 
the  system,  the  Blood  acts  (so  to  speak)  as  the  carrier  of  Oxygen  introduced 
from  the  atmosphere,  to  the  Muscular  and  Nervous  tissues,  to  whose  peculiar 
vital  activity  its  presence  appears  to  be  an  essential  condition,  the  same  element 
being  also  required  in  various  other  metamorphoses  which  form  part  both  of  the 
constructive  and  destructive  operations :  whilst  conversely  it  imbibes  the  Car- 
bonic acid,  which  is  one  of  the  chief  products  of  the  action  of  oxygen  upon  the 
tissues  and  fluids  of  the  body,  and  conveys  this  to  the  lungs  and  skin  for  elimi- 
nation. This  product  is  continually  being  formed  in  such  large  amount,  that  its 
presence  in  the  blood  can  always  be  readily  demonstrated;  and  if  its  elimination 
be  checked  for  even  a  few  minutes,  it  accumulates  to  such  an  extent  as  to  occa- 
sion the  immediate  destruction  of  life. — But  in  addition  to  the  Histogenetic 
materials  and  Oxygen,  on  the  one  hand,  and  the  various  products  of  the  disinte- 
gration of  the  tissues  on  the  other,  the  blood  contains  those  non-azotized  sub- 
stances, which  are  received  into  it  for  the  purpose  of  supplying  the  pabulum  of 
the  Combustive  process;  and  the  union  of  their  carbon  with  oxygen  introduced 
from  the  atmosphere,  which  is  continually  going-on,  becomes  an  additional  source 
of  the  production  of  carbonic  acid,  and  of  its  injurious  accumulation  if  its  elimi- 
nation be  checked. 

154.  From  this  variety  in  the  operations  to  which  the  Blood  is  subservient,  it 
naturally  follows  that  the  changes  which  it  undergoes  in  different  parts  of  its 

sklerations,  which  are  fairly  stated  by  Mr.  Gray. — The  pain  in  the  region  of  the  Spleen, 
which  is  so  commonly  complained-of  by  Chlorotic  patients,  seems  to  be  not  improbably 
connected  with  an  excess  of  the  disintegrating  action  of  the  organ,  the  results  of  which 
manifest  themselves  in  the  extreme  diminution  of  red  corpuscles  in  the  general  mass  of 
the  blood. 


170  or  THE   BLOOD; 

circulation  are  of  a  very  diversified  nature,  and  that  the  composition  of  the  fluid 
in  the  several  parts  of  its  course  will  be  far  from  uniform.  Between  the  blood 
which  is  being  distributed  by  the  systemic  Arteries  to  the  body  at  large,  and 
that  which  is  being  collected  from  it  again  by  the  systemic  Veins,  after  having 
percolated  the  tissues,  there  is  not  only  an  obvious  difference  in  hue,  which  in- 
dicates an  important  change,  but  there  is  also  a  considerable  difference  in  com- 
position, which  is  revealed  by  chemical  analysis  :  and  a  difference  of  a  converse 
nature  presents  itself,  between  the  blood  that  is  on  its  way  to  be  distributed  to 
the  Lungs,  and  that  which  is  returning  from  them.  So,  again,  although  there 
is  no  obvious  dissimilarity  in  physical  characters,  between  the  blood  which  is 
transmitted  to  the  Liver  by  the  vena  portse,  and  that  which  is  carried-off  from  it 
by  the  hepatic  vein,  yet  chemical  analysis  reveals  a  very  remarkable  difference  in 
their  composition,  and  shows  that' the  blood  of  the  ascending  vena  cava  (above 
the  entrance  of  the  hepatic  vein),  that  of  the  right  cavities  of  the  heart,  and 
that  of  the  pulmonary  artery,  differs  from  alt  other  blood  in  the  bodv,  in  contain- 
ing an  appreciable  quantity  of  that  peculiar  sugar  which  is  formed  in  its  passage 
through  the  Liver  (§  132).  In  many  other  cases,  we  know  that  an  important 
difference  must  exist,  although  chemical  analysis  has  not  yet  detected  it ;  thus 
the  blood  of  the  Renal  vein  must  be  more  free  from  the  components  of  the 
urinary  excretion,  than  that  of  the  renal  artery  which  conveys  them  to  the 
kidney;  while  the  blood  of  the  Systemic  veins  in  general  must  contain  them  in 
greater  amount  than  their  corresponding  arteries,  since  they  are  discharged  into 
the  current  during  its  passage  through  the  tissues,  of  whose  disintegration  they 
are  among  the  products.  —  In  the  account  to  be  presently  given  of  the  Blood, 
those  most  general  characters  and  properties  will  be  first  described,  which  it  pre- 
sents in  all  parts  of  its  circulation  ;  the  principal  differences  which  have  been 
substantiated  in  the  composition  of  the  blood  in  the  several  portions  of  its  cir- 
cuit, will  then  be  noticed ;  and,  lastly,  a  summary  will  be  given  of  the  most  im- 
portant of  those  pathological  alterations,  which  it  exhibits  in  disease. 

155.  The  precise  determination  of  the  quantify  of  Blood  contained  in  the 
body,  is  more  difficult  than  might  have  been  first  supposed ;  and  the  estimates 
which  have  been  made  of  it,  have  been  most  strangely  discrepant.  The  entire 
amount  which  flows  from  a  large  arterial  trunk  freely  opened,  can  by  no  means  be 
taken  as  a  measure ;  since,  however  readily  it  may  be  permitted  to  escape,  a  con- 
siderable quantity  still  remains  within  the  blood-vessels,  especially  if  the  heart's 
action  fail  before  the  loss  of  blood  has  proceeded  very  far,  so  that  it  is  not  drawn 
from  the  venous  system.  A  closer  approximation  may  be  made  by  opening  several 
vessels  at  once,  which  was  the  method  adopted  by  Herbst;1  who  estimated  the 
proportion  of  the  weight  of  the  blood  to  that  of  the  entire  body,  to  be  as  1 : 12  in 
the  Ox,  as  1 : 16  in  the  Dog,  as  1 : 18  in  the  Horse,  as  1 : 20  in  the  Goat,  Calf,  Lamb, 
and  Hare,  as  1  : 22  in  the  Sheep  and  Cat,  and  as  1 :  24  in  the  Rabbit.  With  these 
estimates,  the  conclusions  drawn  by  Vanner  from  his  recent  observations  in  the 
abattoirs  of  Paris,  pretty  closely  correspond ;  for  he  is  led  by  them  to  the  belief, 
that  for  horned  cattle  in  general,  the  proportion  does  not  vary  far  from  1  :  20. 3  It 
is  obvious,  however,  that  no  such  method  can  give  more  than  a  minimum;  since, 
even  after  the  most  complete  exsanguination  that  the  freest  opening  of  the  vessels 
can  permit,  a  considerable  quantity  of  blood  is  still  retained  in  them,  and  especially 
in  those  of  the  head.  And  there  are  various  observations  which  lead  to  the 
belief,  that  such  estimates  are  far  too  low  as  regards  Man  ;  since  it  appears  that  a 
quantity  of  blood  equal  to  at  least  one-tenth  of  the  weight  of  his  body,  may  be 
poured-forth  from  his  vessels  within  a  short  time.  Still,  occurrences  of  this  kind, 
of  which  Haller  has  brought  together  an  interesting  collection,3  afford  but  an 
unsafe  basis  for  our  estimate;  since  it  is  necessary  to  allow  for  the  fact,  that 

1  "  De  Sanguinis  quantitate,  qualis  homini  adulto  et  sano  convenit."     Goettingse,  1822. 
0  "  Comptes  Rendus."  torn,  xxviii.  p.  649. 
*  "Elementa  Physiologise,"  vol.  ii.  pp.  3,  4. 


ITS   PHYSICAL,  CHEMICAL,  AND    STRUCTURAL    CHARACTERS.  171* 

when  the  vessels  are  becoming  emptied  of  blood,  a  transudation  of  fluid  takes 
place  into  them  from  the  surrounding  tissues,  as  is  evidenced  by  the  diminution 
in  the  specific  gravity,  and  in  the  increase  in  the  proportion  of  water,  which  are 
apparent  when  even  the  first  and  last  parts  of  the  blood  drawn  at  an  ordinary 
venesection  are  compared  (§  178) :  so  that,  if  the  haemorrhage  be  going-on  for 
some  hours,  a  much  larger  quantity  of  fluid  may  be  poured-forth  from  the  vessels, 
than  was  ever  contained  within  them  at  any  one  time;  and  if  liquids  be  ingested 
during  its  continuance,  a  portion  of  these,  being  at  once  received  into  the  circu- 
lating current,  will  go  to  augment  the  amount  which  escapes  from  it.  Two  re- 
markable instances  are  cited  by  Burdach1  from  Wrisberg;  who  states  that  a  female 
who  died  from  violent  metrorrhagia  had  lost  26  Ibs.  of  blood,  and  that  24  Ibs. 
were  collected  from  the  body  of  a  plethoric  female  who  had  suffered  death  by 
decapitation.  In  the  first  of  these  cases,  it  is  probable  that,  as  death  could  not 
have  been  immediate,  some  increase  took  place  from  the  fluids  of  the  body;  in 
the  second,  however,  the  suddenness  of  the  discharge  of  blood,  and  its  concur- 
rence with  the  destruction  of  life,  must  have  prevented  any  considerable  augmen- 
tation from  this  source;  and  if  any  such  increase  did  take  place,  it  probably  did 
not  exceed  the  amount  of  blood  remaining  undischarged  in  the  vessels.  In  two 
cases  in  which  the  weight  of  blood  which  drained  from  the  bodies  of  decapitated 
criminals  was  determined  by  Profrs.  E.  "Weber  and  Lehman  (allowance  being 
made  for  the  large  quantity  of  water  which  mingled  with  its  latter  portions),  it 
was  found  to  bear  to  the  weight  of  the  body  at  large  almost  exactly  the  ratio  of 
1 :  8v2  Several  circumstances  lead  to  the  belief  that  this  estimate  is  not  far  from 
the  averge ;  but  it  cannot  be  doubted  that  a  considerable  variation  in  the  relative 
amount  of  blood  will  exist  among  different  individuals,3 

2.  Physical,  Chemical,  and  Structural  Characters  of  the  Bloods 

156.  The  Blood  as  it  flows-forth  from  an  opening  in  a  large  vessel,  is  an 
apparently  homogeneous  liquid,  possessing  a  slight  degree  of  viscidity,  with  a 
consistence  and  density  somewhat  greater  than  that  of  water,  but  especially  dis- 
tinguished by  its  colour,  which  is  usually  of  a  bright  scarlet  when  it  is  drawn 
from  an  artery,  and  of  a  dark  purple,  sometimes  almost  approaching  to  black,  when  it 

1  "  Trait^  de  Physiologic,"  traduit  par  Jourdain,  torn.  vi.  p.  119. 

3  See  Prof.  Lehmann's  "  Lehrbuch"  (2nd  edit.),  band  ii.  p.  234. 

8  Another  mode  of  determining  the  total  amount  of  the  circulating  blood  has  been  pro- 
posed by  Prof.  Valentin  ("Repert.  fur  Anat.  and  Phys.,"  band  iii.  p.  281);  who  first 
draws  a  sample  of  blood  from  an  animal,  and  ascertains  the  proportion  of  water  which  it 
contains,  then  injects  a  determinate  quantity  of  water  into  the  vessels,  and  immediately 
draws  fresh  samples  from  different  parts  of  the  body,  in  which  also  he  ascertains  the  pro- 
portion of  the  solid  to  the  fluid  components:  and  from  the  amount  of  dilution  which  the 
last-drawn  blood  exhibits,  as  compared  with  the  first  sample,  he  calculates  the  whole  bulk 
of  the  circulating  fluid.  From  these  data,  Prof.  Valentin  estimated  the  proportion  of 
blood  in  the  Dog  as  1 :  4J,  and  in  the  Sheep  as  1 :  5 ;  so  that  applying  the  former  of  these 
proportions  to  the  Human  body,  a  man  weighing  145  Ibs.  .would  have  32  Ibs.  of  blood,  and 
a  woman  weighing  127  Ibs.  would  have  27  Ibs.  of  blood.  It  can  scarcely  be  doubted  that 
this  statement  is  too  high ;  and  it  is  not  difficult  to  discern  an  important  fallacy  in  the 
method  on  which  it  is  based.  For  however  rapidly  the  operation  may  be  performed,  some 
portion  of  the  water  injected  will  transude  from  the  vessels  into  the  surrounding  tissues, 
and  will  escape  by  the  kidneys ;  and  thus,  the  degree  of  its  dilution  being  diminished,  the 
estimate  of  the  total  amount  of  the  blood  will  be  raised  considerably  above  the  reality. 
It  has  been  more  recently  proposed  by  more  than  one  experimenter,  to  inject,  in  place  of 
water,  some  saline  compound,  whose  presence  in  the  blood  might  easily  be  determined 
quantitively,  and  which  should  neither  be  so  poisonous  as  to  produce  speedy  death,  nor  be 
capable  of  such  rapid  transudation  as  to  escape  too  readily  into  the  tissues  or  the  urine. 
The  sulphate  of  alumina  has  been  employed  for  this  purpose  by  Prof.  Blake  (of  St.  Louis, 
U.  S.)  ;  and  his  experiments  lead  to  the  conclusion  that  the  proportion  of  blood  in  the  body 
of  a  Dog  is  as  1 :  8  or  1 :  9 ;  so  that,  applying  the  same  proportion  to  Man,  the  quantity 
of  blood  in  a  Human  body  weighing  144  Ibs.  would  be  16  or  18  Ibs.  See  Prof.  Dunglison's 
"  Human  Physiology,"  seventh  edit.  vol.  ii.  p.  102. 


172  OF    THE    BLOOD. 

is  drawn  from  a  vein.  This  difference  of  colour,  however,  is  by  no  means  constant ; 
for  arterial  blood  may  sometimes  be  unusually  dark,  whilst  venous  blood  is  occasion- 
ally so  florid  that  it  might  almost  be  taken  for  arterial.  The  former  condition  is 
observable,  when  from  any  cause  the  respiratory  process  is  imperfectly  effected, 
and  may  be  especially  noticed  during  operations  performed  under  the  influence 
of  anaesthetic  agents;  it  has  also  been  remarked  by  Dr.  John  Davy,  as  usually 
characterising  the  arterial  blood  of  the  inhabitants  of  hot  climates ;'  but  in  any 
of  these  cases,  the  ordinary  arterial  hue  is  acquired  by  the  blood,  when  it  has 
been  sufficiently  exposed  to  the  air.  The  florid  hue  is  presented  by  the  venous 
blood  of  animals  which  are  made  to  respire  pure  oxygen  ;  but  it  seems  normal 
with  some  individuals  -whose  respiration  is  peculiarly  active. — The  specific  gravity 
of  the  131  ood  is  stated  by  Nasse,2  as  the  result  of  numerous  observations  to  vary 
(within  the  limits  of  health)  between  1050  and  1059 ;  the  average  being  taken 
as  1055.  The  principal  source  of  this  variation,  is  the  want  of  constancy  in  the 
proportion  of  the  red  corpuscles  in  the  blood ;  for  the  specific  gravity  of  these, 
when  separately  examined,  is  found  to  be  as  high  as  1088-5,  whilst  that  of  the 
liquid  in  which  they  float  is  no  more  than  1028 ;  and  hence  the  specific  gravity 
of  the  blood  of  men  is  usually  higher  than  that  of  women  (§  175),  and  that  of 
the  portion  of  blood  first  drawn  exceeds  that  of  the  portion  which  flows  last 
(§  178). — The  chemical  reaction  of  the  Blood  seems  to  be  invariably  alkaline', 
and  very  important  purposes  are  served  by  the  alkalinity  (§  216). — When  we  add 
that  the  blood  has  a  saltish  taste,  and  a  faint  odour  resembling  that  of  the  pul- 
monary and  cutaneous  exhalations  of  the  animal  from  which  it  is  drawn,  we 
have  enumerated  all  the  characteristics  which  can  be  made-out  by  the  unassisted 
senses. 

157.  When  the  Blood  is  examined  with  the  Microscope,  however,  either  im- 
mediately upon  being  drawn,  or  whilst  it  is  yet  circulating  in  the  vessels  of  the 
living  body  (as  in  the  foot  of  the  Frog,  the  wing  of  the  Bat,  or  any  other  mem- 
branous expansion  of  similar  transparency),  it  is  seen  that  its  apparent  homo- 
geneity is  not  real,  but  that  it  consists  of  two  very  different  components.  These 
are,  a  transparent  and  perfectly  colourless  liquid  which  is  known  as  the  Liquor 
Sanyuinis,  and  a  set  of  Corpuscles  which  are  suspended  in  it :  the  great  mass  of 
these  last  present  a  distinctly  red  hue,  and  it  is  to  their  presence  alone  that  the 
colour  of  the  blood  is  due;  but  there  are  also  to  be  seen,  scattered  among  the 
red,  a  few  which  are  colourless,  and  which  differ  from  the  red  in  some  other  par- 
ticulars presently  to  be  noticed.  —  On  the  other  hand,  when  the  Blood  has  been 
drawn  from  the  body,  and  is  allowed  to  remain  at  rest,  it  undergoes  a  spontaneous 
coagulation,  in  the  course  of  which  it  separates  into  a  red  Crassamentum,  and  a 
nearly  colourless  Serum.  The  ' crassamentum'  or  'clot'  is  composed  of  a  net- 
work of  Fibrin,  presenting  a  more  or  less  distinct  fibrous  texture ;  in  the  meshes 
of  which  the  Corpuscles,  both  red  and  colourless,  are  involved,  together  with  a 
certain  amount  of  serous  fluid.  The  '  serum/  which  is  the  same  with  the  *  liquor 
ganguinis'  deprived  of  its  fibrin,  coagulates  by  heat,  and  is  therefore  known  to 
contain  Albumen ;  and  if  it  be  exposed  to  a  high  temperature,  sufficient  to  de- 
compose the  animal  matter,  a  considerable  amount  of  earthy  and  alkaline  Salts 
remains. — Thus  we  have  four  principal  components  in  the  Blood;  namely,  Fibrin, 
Albumen,  Corpuscles,  and  Saline  matter.  In  the  circulating  blood,  they  are 
thus  combined : — 

Fibrin  ~\ 

Albumen       >•  In  solution,  forming  Liquor  Sanguinis. 

Salts  J 

Corpuscles, — suspended  in  Liquor  Sanguinis. 

•  "Anatomical  and  Physiological  Researches,"  vol.  ii.  p.  140. — This  fact,  which  har- 
monizes with  the  inference  to  be  drawn  from  the  observed  results  of  a  high  external  tem- 
perature in  reducing  the  excretion  of  carbonic  acid  (Chap,  vn.,  Sect.  2),  is  of  great  practical 
importance 

9  Wagner's  "  Handworterbuch  der  Physiologic,"  Art.  'Blut,'  band  i.  p.82. 


FIG.  50. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.        173 
But  in  coagulated  blood,  they  are  combined  as  follows  : — • 

Corpuscles  }  ForminS  Crassamentum,  or  Clot. 

Albumen      )  •„        .   .       .        ,    ,.        ,.       .       -, 
Salts  (  Remaimrig  in  solution,  forming  Serum. 

The  cHpnge  from  the  one  condition  to  the  other  is  due  to  the  fibrillation  of  the 
Fibrin  ;  which  usually  takes  place  so  speedily,  as  to  involve  the  Corpuscles  float- 
ing in  the  'liquor  ganguinis/  before  they  have  time  to  subside;  although,  under 
various  conditions  hereafter  to  be  described  (§§  205,  206),  it  may  occur  in  such 
a  manner,  that  the  clot,  or  a  portion  of  it,  is  left  colourless. 

158.  The  Red  Corpuscles  of  the  Blood  (commonly,  but  erroneously,  termed 
'  globules')  are  cells  of  a  flattened  or  discoidal  form,  which,  in  Man,  as  in  most 
of  the  Mammalia,  have  a  distinctly-circular  outline.  In  the  discs  of  Human 
blood,  when  this  is  examined  in  its  natural  condition,  the  sides  are  somewhat 
concave;  and  there  is  a  bright  spot  in  the 
centre,  which  has  been  regarded  by  many 
as  indicating  the  existence  of  a  nucleus; 
though  it  is  really  nothing  else  than  an 
effect  of  refraction,  and  may  be  exchanged 
for  a  dark  one  by  slightly  altering  the  focus 
of  the  Microscope  (Fig.  50).  The  form  of 
the  disc  is  very  much  altered  by  various  re- 
agents ;  for  the  membrane  which  composes 
its  exterior,  or  cell-wall,  is  readily  permeable 
by  liquids ;  so  as  to  admit  of  their  passage, 
according  to  the  laws  of  Endosmose,  either 
inwards  or  outwards,  as  the  relative  density 
of  the  contents  of  the  cell  and  of  the  sur- 
rounding fluid  may  direct.  Thus,  if  the 
Rod  Corpuscles  be  treated  with  water,  or 
with  a  solution  of  sugar,  albumen,  or  salt,  which  is  of  less  density  than  the 
liquor  sanguinis,  there  is  a  passage  of  this  liquid  into  the  cell ;  the  disc  first  be- 
comes flat,  and  then  double-convex,  so  that  the  central  spot  disappears ;  and  by 
a  continuance  of  the  same  process,  it  at  last  becomes  globular,  and  finally  bursts, 
the  cell-wall  giving  way,  and  allowing  the  diffusion  of  its  contents  through  the 
surrounding  liquid.  If,  on  the  other  hand,  the  Red  Corpuscles  be  treated  with 
a  thick  syrup  or  with  a  solution  of  albumen  or  of  salt,  they  will  be  more  or 
less  completely  emptied,  and  caused  to  assume  a 
shrunken  appearance;  (Fig.  51)  the  first  effect  of 
the  process  being  to  increase  the  concavity,  and  to 
render  the  central  spot  more  distinct.1  It  is  prob- 
able that  the  Blood-corpuscles,  even  whilst  they 
are  circulating  in  the  living  vessels,  are  linble  to 
alterations  of  this  kind,  from  variations  in  the 
density  of  the  fluid  in  which  they  float;  and  that 
such  alterations  may  be  constantly  connected  with 
certain  disordered  states  of  the  system.2  Thus, 
even  without  such  an  alteration  in  the  Blood  as 
would  constitute  disease,  its  proportion  of  water  may 

1  A  large  number  of  experiments  of  this  kind  were  made,  and  their  results  accurately 
recorded,  by  Hewson  (see  his  "Inquiry  into  the  Properties  of  the  Blood,"  1782,  and  his 
"  Description  of  the  Red  Particles  of  the  Blood,"  1788),  who  drew  from  them  the  inference 
of  the  vesicular  character  of  the  Red  Corpuscles.  These  experiments  were  repeated  and 
varied  by  other  physiologists,  of  whose  results  a  table  has  been  given  by  Mr.  Ancell 
("Lectures  on  the  Physiology  and  Pathology  of  the  Blood,"  in  the  "Lancet,"  Dec.  7. 
1839);  but  the  facts  stated  in  the  text  are  those  of  most  importance,  and  their  true 
rationale  seems  to  have  been  first  given  by  Dr.  G.  0.  Rees  and  Mr.  S.  Lane.  (See  their 
Memoir  'On  the  Structure  of  the  Blood  Corpuscle,'  in  "  Guy's  Hospital  Reports,"  No.  xiii.) 

1  Seo  Dr.  G.  0.  Rees's  'Gulstonian  Lectures'  in  the  "  Medical  Gazette"  for  1845. 


Red  Corpuscles  of  Human  Blood ;  re- 
presented at  a,  as  they  are  seen  when 
rather  beyond  the  focus  of  the  microscope ; 
and  at  6,  as  they  appear  when  within  the 
focus. 


[FiG.  51. 


ft 


'I 


B  A 

Red  corpuscles  of  the  ox,  mag 
nified  two  diameters  (from  Todd 
and  Bowman);  A,  in  their  natu- 
ral state ;  B,  altered  by  a  men- 
strum  of  higher  density.] 


174 


OF  THE   BLOOD; 


be  temporarily  so  much  diminished  by  diuresis  or  excessive  perspiration,  unbalanced 
by  a  corresponding  ingestion  of  liquid,  that  the  corpuscles  may  be  made  to  present 
a  granulated  edge;  which  is  rendered  smooth  again  by  the  dilution  of  the  liquor 
sanguinis  with  water.  We  hence  see  the  necessity,  in  examining  the  Blood  micro- 
scopically, for  employing  a  fluid  for  its  dilution,  that  shall  be  as  nearly  as  possible 
of  the  same  character  with  its  ordinary  i  liquor  sanguinis/  ' — Microscopic  observ- 
ers were  formerly  divided  upon  the  question,  whether  or  not  the  Red  Corpuscles 
of  the  blood  of  Man  and  other  Mammalia  contain  a  nucleus  ;  but  of  late  there  has 
been  a  general  accordance  in  the  statement,  that,  in  the  fully-formed  discs,  no  nu- 
cleus is  discoverable,  although  it  may  be  sometimes  seen  in  cells  whose  formation 
seems  to  be  incomplete;  and  from  the  observations  of  Mr.  Paget  and  of  Mr. 
Wharton  Jones,  it  would  seem  that  we  are  to  regard  the  absence  of  nucleus  as 
marking  a  more  advanced  stage  of  development,  than  that  which  obtains  in  the 
blood-corpuscles  of  the  lower  Vertebrata,  or  in  the  early  condition  of  those  of  the 
highest  (§  168). — In  all  Oviparous  Vertebrata,  without  any  known  exception,  the 
Red  Corpuscles  are  oval, — (Fig.  52)  the  proportion  between  their  long  and  their 
short  diameters,  however,  being  subject  to  much  variation;  and  their  nuclei 


FIG.  53. 


[Fie.  52. 


B 


(D 


Red  corpuscles  of  the  pigeon,  mag- 
nified 400  diameters  (from  Todd  and 
Bowman) ;  A,  unaltered,  with  two  or 
three  colourless  particles;  B,  treated 
with  acetic  acid,  which  more  clearly 
•Jevelopes  the  cell  wall  and  nucleus.] 


Corpuscles  of  Frog's  blood  ;  1,  1,  red  cor- 
puscles  seen  on  their  flattened  face;  2,  the 
same  turned  nearly  edgeways  ;  3,  colourless 
corpuscle  ;  4,  red  corpuscles  altered  by  dilute 
acetic  acid. 


may  always  be  brought  into  view  by  treatment  with  acetic  acid,  when  not  at  first 
visible.  In  the  red  particles  of  the  Frog,  which  are  far  larger  than  those  of 
Man,  a  nucleus  can  be  observed  to  project  somewhat  from  the  central  portion  of 
the  oval,  even  during  their  circulation  (Fig.  53,  1,  1);  and  it  is  brought  into 
extreme  distinctness  by  the  action  of  acetic  acid,  which  renders  the  remainder 
of  the  particle  extremely  transparent,  whilst  it  gives  increased  opacity  to  the 
nucleus,  which  is  then  seen  to  consist  of  a  granular  substance  (4).  In  the  still 
larger  blood-disc  of  the  Proteus  and  Siren,  this  appearance  is  yet  more  distinct.2 
159.  The  form  of  the  Red  Corpuscles  is  not  unfrequently  seen  to  change 
during  their  circulation ;  but  this  is  generally  in  consequence  of  pressure,  from 
the  effects  of  which,  however,  they  quickly  recover  themselves.  In  the  capillary 
vessels,  they  sometimes  become  suddenly  elongated,  twisted,  or  bent,  through  a 
narrowing  of  the  channel ;  and  this  change  may  take  place  to  such  a  degree,  as 
to  enable  the  disc  to  pass  through  an  aperture  which  appears  very  minute  in  pro- 
portion to  its  diameter.  When  undergoing  spontaneous  decomposition,  the 
blood-discs  become  granulated,  and  sometimes  (as  long  since  noticed  by  Hewsoii) 

1  By  Wagner,  the  filtered  serum  of  frog's  blood  is  recommended  for  this  purpose.  Weak 
solutions  of  salt  or  sugar,  and  urine,  answer  tolerably  well ;  but,  as  Mr.  Gulliver  remarks, 
all  addition  must  be  avoided,  when  it  is  intended  to  measure  the  corpuscles,  or  to  ascertain 
their  true  forms;  since  even  the  serum  of  one  Mammal  reacts  injuriously  on  the  blood™ 
iiscs  of  another.  See  "  Philos.  Magaz.,"  Jan.  and  Feb.,  1840. 

'  See  «•  Penny  Cyclopaedia,"  Art.  *  Siren.' 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.         176 


even,  mulberry-shaped  ;  and  particles  in  which  these  changes  appear  to  be  com- 
mencing:, may  be  found  in  the  blood  at  all  times. — The  size  of  the  blood-discs  is 
liable  to  considerable  variation,  even  in  the  same  individual ;  some  being  met- 
with  with  as  much  as  one-third  larger,  whilst  others  are  one-third  smaller,  than 
the  average.  The  diameter  of  the  corpuscles  bears  no  constant  relation  to  the 
size  of  the  animal,  even  within  the  limits  of  the  same  class ;  thus,  although 
those  of  the  Elephant  are  the  largest  among  Mammalia  (as  far  as  is  hitherto 
known),  those  of  the  Mouse  tribe  are  far  from  being  the  smallest,  being,  in  fact, 
more  than  three  times  the  diameter  of  those  of  the  Musk  Deer.  There  is,  how- 
evei,  as  Mr.  Gulliver  has  remarked,  a  more  uniform  relation  between  the  size  of 
the  animal  and  that  of  its  blood-discs,  when  the  comparison  is  made  within  the 
limits  of  the  same  order.  In  Man,  their  diameter  varies  from  about  l-4000th  to 
l-2SOOth  of  an  inch,  the  average  diameter  being  probably  about  l-3200th;  and 
their  average  thickness,  according  to  the  same  excellent  observer,  is  about 
1-12, 400th  of  an  inch.1  According  to  the  recent  estimates  of  Yierordt,  a  cubic 
centimetre  of  blood  (which  is  no  more  than  about  6-100ths  of  a  cubic  inch)  con- 

1  A  Tabular  summary  of  Mr.  Gulliver's  very  numerous  and  accurate  measurements  of 
the  Red  Corpuscles  of  the  Blood  of  different  animals,  from  all  the  classes  and  most  of  the 
orders  of  the  Vertebrate  series,  is  contained  in  the  "  Proceedings  of  the  Zoological 
Society,"  No.  cii.,  and  also  in  his  Edition  of  the  "  Works  of  Hewson"  already  referred  to, 
published  by  the  Sydenham  Society  (p.  237).  From  these,  the  following  measurements 
of  the  blood  of  domestic  animals  (expressed  in  fractions  of  an  English  inch)  may  be  se- 
lected, as  the  most  likely  to  become  of  interest  in  Juridical  inquiries,  in  which  it  is  fre- 
quently of  importance  to  ascertain  the  precise  source  of  stains,  whose  sanguineous  cha- 
racter has  been  determined. 


Man 1-3200 

Dog 1-3532 

Hare 1-3560 

Rabbit 1-3607 

Rat 1-3754 

Mouse 1-3814 

Ass 1-4000 


Pig 1-4230 

Ox 1-4267 

Red  Deer 1-4324 

Cat 1-4404 

Horse 1-4600 

Sheep '. 1-5300 

Goat 1-6366 


Thus  it  appears  quite  possible  to  distinguish  the  blood  of  all  the  animals  enumerated, 
from  that  of  Man,  by  the  measurement  of  the  diameter  of  the  Red  Corpuscles  ;  those  of 
the  Dog  and  of  the  Rodents  approaching  his  most  nearly  in  size,  while  those  of  the  Rumi- 
nant and  Pachydermatous  quadrupeds,  and  of  the  Cat,  are  considerably  smaller.  —  It  ia 
important,  however,  to  bear  in  mind,  that  the  specimens  of  blood  submitted  to  examina- 
tion in  Juridical  inquiries,  will  for  the  most  part  have  been  dried  ;  and  it  is  therefore  of 
consequence  to  know  the  comparative  dimensions  of  the  blood-discs,  after  they  have  been 
submitted  to  this  process.  These  are  given  as  follows  by  Schmidt,  in  his  recent  work  on 
the  diagnosis  of  suspicious  spots  in  criminal  cases  ("Die  Diagnostik  verdachtiger  Flecke 
im  Criminalfaller  ")  ;  the  measurements  being  expressed  in  decimals  of  a  millimetre, 

Maximum. 
0-0080 
0-0074 
0-0070 
0-0068 


Mean. 
Man  .....................................  0-0077 

Dog  ......................................  0-0070 

Rabbit  ................................  0-0064 

Rat  ......................................  0-0064 


Minimum. 
0-0074 
0-0066 
0-0060 
0-0060 
0-0060 
0-0058 
0-0054 
0-0053 
0-0053 
0-0040 


Pig  ......................................  0-0062  0-0065 

Mouse  ...................................  0-0061  0-0065 

Ox  ......................................  0-0058  00062 

Cat  .......................................  0-0056  0-0060 

Horse  ....................................  0-0057  0-0060 

Sheep  ....................................  0-0045  0-0048 

The  relative  sizes  of  the  Red  Corpuscles  expressed  by  this  Table,  will  be  seen  to  cor- 
respond closely  with  those  assigned  by  Mr.  Gulliver,  in  every  case  but  that  of  the  Pig  ; 
for  its  blood-corpuscle  being  represented  as  relatively  larger  in  the  dried  blood  than  in  the 
moist,  there  must  certainly  be  a  mistake  on  one  side  or  the  other.  —  The  oval  form  and  pro- 
minent nucleus  of  the  Red  Corpuscles  of  all  the  oviparous  Vertebrata,  enable  them  to  be 
distinguished  from  those  of  Man  without  the  slightest  difficulty;  consequently  no  question 
can  ever  lie  between  a  stain  left  by  the  blood  of  a  Fowl,  a  Turtle,  or  a  Cod,  and  that  left 
by  Human  blood,  when  the  corpuscles  can  be  distinctly  made-out  with  the  assistance  of 
the  microscope. 


176 


OF   THE   BLOOD; 


tains  no  fewer  than  5,055,000  red  corpuscles  :  whilst  by  Welker  the  number  in 
the  same  quantity  is  estimated  at  4,600, 000. l  —  The  colour  of  the  Red  Corpus- 
cles is  very  pale  when  they  are  lying  in  a  single  stratum;  and  it  is  only  when 
we  see  three  or  four  superposed  one  upon  onother,  that  the  full  deep  red  tint  of 
their  contents  becomes  apparent.  The  cause  of  the  difference  in  hue  between 
the  corpuscles  of  arterial  and  those  of  venous  blood,  will  be  considered  here- 
after (§  182). 

160.  The  principal  part  of  the  cell-contents  of  the  Red  Corpuscles  is  formed 
by  the  two  compounds,  Globulin,  which  is  a  coagulable  substance  nearly  allied 
to  albumen,  and  Haematin,  to  which  their  colour  is  altogether  due ;  the  precise 
composition  of  the  ee\\-walh  has  not  not  been  determined.  —  The  following  is 
given  by  Prof.  Lehmann2  as  the  relative  Chemical  constitution  of  the  Red  Cor- 
puscles and  of  the  Liquor  Sanguinis,  which  there  is  a  great  advantage  in  thus 
bringing  into  comparison  : — 


1000  parts  of  Red  Corpus&les  contain 

Water 688-00 

Solid  residue 312-00 

Haematin  (including  iron) 16-75 

Globulin  and  cell-membrane 282-22 

Fat 2-31 

Extractive  matters 2-60 

Mineral  substances  (exclusive  of  iron)  8-12 

Chlorine > 1-686 

Sulphuric  acid 0-066 

Phosphoric  acid 1-134 

Potassium 3-328 

Sodium 1-052 

Oxygen 0-667 

Phosphate  of  Lime 0-114 

Phosphate  of  Magnesia 0-073 


1000  parts  of  Liquor  Sanguinis  contain 

Water 902-90 

Solid  residue 97-10 


Fibrin 

Albumen 

Fat 

Extractive  matters., 
Mineral  substances. 


4-05 
78-84 
1-72 
3-94 
8-55 


Chlorine 3-644 

Sulphuric  acid 0-115 

Phosphoric  acid 0-191 

Potassium 0-323 

Sodium 3-341 

Oxygen 0-403 

Phosphate  of  Lime 0-311 

Phosphate  of  Magnesia 0-222 


From  this  we  see  that  not  only  do  the  Haematin  and  Globulin  of  the  Corpuscles 
replace  the  Fibrin  and  Albumen  of  the  Liquor  Sanguinis,  but  the  proportion  of 
Fat  in  the  former  is  considerably  greater  than  in  the  latter;  and  that  although 
the  whole  amount  of  mineral  matter  (excluding  the  iron  of  Hasmatin,  which 
would  amount  to  I'll),  is  nearly  the  same  in  the  Corpuscles  as  in  the  Liquor 
Sanguiuis,  yet  there  is  a  most  remarkable  and  significant  difference  in  its  con- 
stituents in  the  two  cases  respectively.  For  while  the  Chlorine  of  the  corpuscles 
is  to  that  of  the  liq.  sang,  as  1  :  2-16,  the  Phosphoric  acid  of  the  corpuscles  is 
to  that  of  the  liq.  sang,  as  nearly  6:1;  and  whilst  the  Sodium  of  the  corpus- 
cles is  to  that  of  the  liq.  sang,  as  1  :  3-3,  the  Potassium  of  the  corpuscles  is  to 
that  of  the  liq.  sang,  as  10-3  to  1.  Hence  it  is  obvious  that  the  Chloride  of 
Sodium  of  the  blood  must  be  principally  contained  within  the  liquor  sanguinis, 
whilst  the  Potash  of  the  blood  is  almost  wholly  included  in  the  substances  of 
the  Corpuscles ;  and  from  the  excess  of  Phosphorus  in  the  corpuscles,  as  well  as 
of  Fat,  it  may  be  fairly  concluded,  that  it  is  in  them  that  the  peculiar '  phospho- 
rized  fats'  are  chiefly  formed.  —  These  facts  seem  to  suggest  a  very  important 
office  for  the  Red  Corpuscles,  which  is  in  harmony  with  all  we  know  of  the  ratio 
that  their  amount  in  different  animals,  and  in  different  individuals  of  the  Human 
species,  bears  to  the  development  of  nervo-muscular  power  (§  210) ;  namely, 
that  they  are  especially  concerned  in  preparing  the  pabulum  for  the  Nervous  and 

1  See  Prof.  Lehmann's  "  Physiologischen-Chemie,"  2nd  edit.,  band  ii.  p.  194. 

•  "Physiological  Chemistry"  (translated  by  Dr.  Day),  vol.  ii.  p.  160.  —  It  is  to  the  ad- 
mirable Essay  of  Schmidt,  "  Characteristic  der  Cholera,"  that  Physiologists  and  Chemists 
are  indebted,  for  the  first  direction  of  their  attention  to  the  importance  of  separately  es- 
timating the  composition  of  these  two  principal  constituents  of  the  Biood,  and  for  the  in- 
dication of  the  means  of  doing  so. 


ITS   PHYSICAL,    CHEMICAL,   AND   STRUCTURAL   CHARACTERS.        177 

Muscular  tissues,  the  former  of  which  is  distinguished  by  the  presence  of  phos- 
phorized  fats,  and  the  latter  by  the  remarkable  predominance  of  the  potash- 
salts.1  And  this  view  derives  further  confirmation  from  the  fact,  that  a  flesh- 
diet  seems  to  have  a  decided  effect  in  promoting  the  formation  of  the  red  cor- 
puscles (§  177).  The  Ked  Corpuscles  appear  to  have  a  remarkable  power  of 
absorbing  certain  gases ;  for  it  has  been  found  by  Van  Maack  and  Scherer,  that 
a  solution  of  haematin  imbibes  a  considerable  amount  of  oxygen,  the  latter  of 
these  chemists  having  also  ascertained  that  after  the  absorption  of  oxygen,  there 
is  a  slight  development  of  carbonic  acid ;  whilst  it  has  been  proved  by  the  ex- 
periments of  Davy,  Nasse,  Scherer,  Magnus,  and  Lehmann  (Op.  cit.,  vol.  ii. 
p.  190),  that  the  capacity  of  defibrinated  blood  (i.  e.  of  serum  +  corpuscles)  for 
absorbing  oxygen  and  carbonic  acid,  is  much  greater  than  that  of  serum  alone, 
being  at  least  twice  as  much  for  equal  volumes.  Hence  it  seems  certain,  that 
the  Red  Corpuscles  must  contain  a  large  proportion  of  the  gases  of  the  blood 
(§  179). — The  Red  Corpuscles  are  considerably  heavier  than  the  serum  in  which 
they  are  suspended;  their  normal  specific  gravity  being  from  1088-5  to  1088*9 
in  man,  and  from  1088-0  to  1088-6  in  woman;  while  that  of  the  Serum  averages 
1028. 

161.  In  addition  to  what  has  been  already  stated  of  the  influence  of  water, 
saline  and  other  solutions,  and  acetic  acid,  upon  the  form  and  condition  of  the 
Red  Corpuscles,  the  following  facts  may  be  stated  with  regard  to  the  effects  of 
these  and  other  reagents. — According  to  Miiller,2  the  envelopes  of  the  corpuscles 
which  have  been  caused  to  burst  by  the  action  of  water,  remain  unchanged  in 
the  liquid  for  twenty-four  hours  or  more;  but  after  remaining  for  some  days  in 
contact  with  it,  they  are  dissolved  by  it.  The  nuclei  of  the  nucleated  corpuscles, 
however,  resist  its  solvent  action;  and  these  behave,  when  treated  with  acids  and 
alkalies,  as  fibrin  or  coagulated  albumen  would  do.  The  action  of  acetic  acid 
upon  the  wall  of  the  corpuscle  is  not  that  of  solution^  for  the  membrane  is  still 
distinguishable  as  a  delicate  film  around  the  nucleus,  and  may  be  brought  into 
more  obvious  view  by  tincture  of  iodine ;  but  it  seems  to  occasion  the  discharge 
of  the  coloured  contents  of  the  vesicle,  either  by  causing  a  contraction  or  col- 
lapse of  its  wall,  or  (more  probably)  by  augmenting  its  permeability.  The 
action  of  the  mineral  an'ds  upon  the  red  corpuscles  is,  quite  different ;  for  they 
occasion  a  coagulation  of  the  contents  of  these  cells  in  their  interior^  so  that 
they  are  no  longer  distended  by  water;  and  this  without  producing  any  other 
change  of  shape,  than  a  slight  corrugation.  Chlorinepsaid  alcohol,  produce  a 
similar  effect.  On  the  other  hand,  the  corpuscles  are  entirely  dissolved  by  the 
mineral  alkalies  and  by  ammonia  j  the  cell-walls  (and  nuclei)  disappearing  com- 
pletely, and  the  cell-contents  being  diffused  through  the  solution.  According  to 
Hunefeld  and  Simon,  the  walls  of  the  corpuscles  are  dissolved,  and  their  con- 
tents set  free,  when  they  are  treated  either  with  bile  or  with  ether ;  ifc  is  also 
affirmed  by  Simon,  that  olive  oil  exerts  a  like  solvent  power;  and  Hunefeld 
states  that  pure  urea  causes  the  rupture  and  partial  solution  of  the  cell-walls 
and  the  dispersion  of  their  contents.3  (An  admixture  of  urine  with  the  blood 
seems  to  exert  no  other  influence  upon  the  corpuscles,  than  a  saline  solution  of 
equal  density  would  do,  as  was  long  since  ascertained  by  Hewson.)  —  It  is 

1  So  long  as  the  error  of  identifying  the  substance  of  Muscle  with  the  Fibrin  of  the 
Blood  prevailed  amongst  Chemists  and  Physiologists,  the  idea  stated  above  would  have  had 
little  weight;  but  now  that  we  know  that  no  special  relation  between  them  exists,  we  are 
free  to  attribute  the  source  of  the  Muscular  structure  to  whichever  component  of  the 
Blood  seems  most  likely  to  afford  it;  and  in  the  absence  of  any  very  positive  distinction 
between  the  composition  and  properties  of  Albumen  and  Globulin,  the  peculiar  relation 
between  the  mineral  constituents  of  Muscle  and  those  of  the  Red  Corpuscles,  seems  to  be 
the  surest  guide  that  we  can  adopt. 

a  "Manuel  de  Physiologic,"  4ieme  edit.,  traduit  par  Jourdain,  torn.  i.  p.  92. 

9  See  Simon's  "Animal  Chemistry,"  translated  by  Dr.  Day,  pp.  97 — 100,  Am.  Ed.,  and 
Hiineteld  "  Der  Chemismus  in  Thierischen  Organisation." 
12 


178  OF   THE   BLOOD; 

affirmed  by  Lehmann,  however,  that  the  solution  of  the  wall  of  the  Corpuscles 
is  usually  rather  apparent  than  real ;  for  that  in  very  few  cases  is  it  actually  dis- 
solved, being  generally  transformed  into  a  mucous  or  gelatinous  condition,  in 
which  it  ceases  to  be  distinguishable,  in  consequence  of  its  co-efficient  of  refrac- 
tion being  the  same  with  that  of  the  plasma.  And  he  founds  this  conclusion, 
not  merely  upon  the  fact  that  the  capsule  is  often  made  visible  again,  either  in  its 
integral  state  or  in  fragments,  by  the  addition  of  tincture  of  iodine  or  of  spme 
saline  solutions;  but  also  upon  the  viscid  and  glutinous  condition  of  the  blood, 
after  the  addition  of  dilute  organic  acids,  alkaline  carbonates,  iodide  of  potas- 
sium, and  other  substances.  For  these  reagents  do  not  reduce  either  the  liquor 
sanguinis  or  the  serum  to  a  state  in  which  it  can  be  drawn-out  in  threads,  and 
hence  this  must  depend  upon  the  presence  of  the  corpuscles;  whilst,  moreover, 
on  neutralizing  with  acids  or  with  alkalies  blood  which  has  been  thus  changed, 
or  on  adding  to  it  a  solution  of  iodine  or  sulphate  of  soda,  the  cell-walls  of  the 
corpuscles  agnin  become  visible,  and  the  blood  loses  its  viscidity.  It  is  further 
remarked  by  Prof.  Lehmann,  that  some  of  the  Red  Corpuscles  resist  the  influence 
of  reagents  much  more  than  others  do;  and  he  infers  that  the  latter  are  the 
older  cells,  as  having  the  strongest  tendency  to  disintegration  ;  whilst  those  which 
present  an  unusual  resisting  power,  he  infers  to  be  young  cells  which  have  not 
yet  acquired  the  normal  characters  of  the  red  corpuscles.1 

162.  The  Red  Corpuscles,  when   freely  floating  in  the  liquor  sanguinis  of 
blood  no  longer  in  motion,  exhibit  a  marked  tendency  to  approximate  one  an- 
other; usually  coming  into  contact  by  their  flattened 

[Fro.  54.  surfaces,  so  that  a  number  of  them  thus  aggregated 

present  the  appearance  of  a  pile  of  coins  (Fig.  54,  b,  c)  ; 
or,  if  the  stratum  be  too  thin  to  permit  them  to  lie  in 
this  manner,  partially  overlapping  one  another  (Fig. 
54,  a),  or  even  adhering  by  their  edges,  which  then  fre- 
quently become  polygonal  instead  of  circular.  The  cor- 
puscles when  thus  adherent,  resist  the  influence  of 
forces  which  tend  to  detach  them,  and  will  even  undergo 
considerable  changes  of  shape,  rather  than  separate 
from  each  other;  if  forced  asunder,  however,  they 

sesume  their  normal  form.  After  thus  remaining  adherent  for  a  time,  they  seem 
to  lose  their  attractive  force ;  for  they  are  then  seen  to  separate  from  each  other 
spontaneously.  This  peculiar  tendency  to  aggregation  is  doubtless  one  of  the 
circumstances  which  influences  the  coagulation  of  the  blood;  it  is  most  strongly 
manifested  in  inflammatory  blood,  and  assists  in  the  production  of  the  bufly  coat 
(§205);  whilst,  on  the  other  hand,  it  seems  to  be  neutralized  by  the  action  of 
most  saline  substances,  since,  if  these  be  added  to  the  blood,  the  corpuscles  do 
not  run  together. 

163.  Besides  the  red  corpuscles  of  the  Blood,  there  are  others  which  possess 
no  colour,  and  might  seem  to  have  a  function  altogether  different;  these  are 
known  as  the  White  or  colourless  corpuscles.     Their  existence  has  long  been  re- 
cognized in  the  blood  of  the  lower  Vertebrata,  where,  from  being  much  smaller 
than  the  red  corpuscles,  as  well  as  from  differing  widely  in  shape,  they  could 
readily  be  distinguished  (Fig.  53,  c).     But  it  is  only  of  late  (chiefly  through  the 
researches  of  Gulliver,2  Addison,3  and  others),  that  they  have  been  recognized 
in  the   blood  of  Man   and  other  Mammalia;  their  size  being  nearly  the  same 
with  that  of  the  red  corpuscles ;  and  the  general  appearance  of  the  two  (owing 
to  the  circular  form  of  the  latter,  and  the  absence  of  a  central  nucleus.)  being 
less  diverse  (Fig.  55).     It  is  remarkable  that,  notwithstanding  the  great  variations 
in  the  size  of  the  red  corpuscles  in  the  different  classes  of  Vertebrata,  the  dimen- 

1  Op.  cit.,  vol.  ii.  pp.  184,  185. 

a  Notes  and  Appendix  to  Translation  of  "  Gerber's  General  Anatomy." 

3  "  Transactions  of  Provincial  Medical  Association,"  1842  and  1843. 


ITS   PHYSICAL,  CHEMICAL,  AND    STRUCTURAL    CHARACTERS.  179 

sions  of  the  colourless  corpuscles  are  extremely  constant  throughout ;  their  diameter 
being  seldom  much  greater  or  less  than  1 -3000th  of  an  inch  in  the  warm-blooded 
Vertebrata,  and  1 -2500th  of  an  inch  in  Reptiles.  This  holds  good  even  in  those 
animals,  — such  as  the  Musk-Deer,  and  the  Proteus,  —  which  present  the  widest 
departure  from  the  general  standard  in  the  size  of  their  red  corpuscles ;  so  that 
the  colourless  corpuscle  is  as  much  as  four  times  the  diameter  of  the  red,  in  one 
instance  ;  whilst  it  is  not  one-eighth  of  the  long  diameter  of  the  red,  in  the 
other. — The  aspect  of  the  Colourless  corpuscles  under  the  microscope  is  by  no 
means  constant;  but  their  variations  seem  to  depend  upon  their  degree  of  de- 
velopment, and  all  gradations  from  one  condition  to  another  may  be  readily 
traced.  In  their  early  state  (in  which  they  most  resemble  the  corpuscles  of  the 
chyle  and  lymph),  the  cell-membrane  can  scarcely  be  distinguished  from  the 
large  nucleus  to  which  it  is  applied  (Fig.  55,  a,  £») ; 
unless  the  cell  be  distended  with  water  or  acetic  acid,  FIG.  55. 

which    enables  us   to   see  that  the  nucleus   is  a  soft  d, 

granular  tuberculated  mass,  which  is  disposed  to  break- 
up readily  into  two  or  more  fragments,  especially  if  JL 
acetic  acid  be  added  (e,  e).  In  a  later  stage,  how-  V 
ever,  the  nucleus  is  easily  distinguished  without  the  ^ 
use  of  water  or  reagents;  but  sometimes  we  find  it  V  JL 
apparently  dispersed  spontaneously  into  numerous  iso-  /^  f( 
lated  particles,  which  give  to  the  entire  cell  a  some-  ^J 
what  granular  and  tuberculated  aspect,  and  which  Colourless  Blood-corpua- 
may  frequently  be  seen  in  molecular  movement  within  cfes,  or  Lymph-corpuscles 
it:  when  these  corpuscles  are  treated  with  a  dilute  of  the  Blood;  — a,  6,  small 
solution  of  potash,  they  speedily  burst  and  discharge  ^VhTraciT  d^/^f  on 
their  granules,  whose  molecular  movement  still  con-  their  flat  side  at  a,  and  edge- 
tinues.  The  Colourless  corpuscles  possess,  moreover,  wise  at  b;  c,  c,  the  same, 
a  higher  refracting  power  than  the  red;  from  which  with  obvious  nuclei;  d,  d, 
they  are  further  distinguished  by  their  greater  firm-  lar&e.r  cells'  with  orisinally- 
ness,  and  by  the  absence  of  any  disposition  to  adhere  ^glp  treated61  with  *ao«tio 
to  each  other;  so  that,  when  a  drop  of  recent  acid/ showing  the  breaking- 
blood  is  placed  between  two  strips  of  glass,  and  these  up  of  the  nuclei, 
are  gently  moved  over  one  another,  the  white  corpus- 
cles may  be  at  once  recognized  by  their  solitariness,  in  the  midst  of  the  rows 
and  irregular  masses  formed  by  the  aggregation  of  the  red.  This  is  still  better 
seen  in  inflammatory  blood ;  in  which  the  Red  corpuscles  have  a  peculiar  ten- 
dency to  adhere  to  one  another,  so  that  the  distinctness  of  the  White  is  more 
marked  (Fig.  63). 

164.  The  Colourless  corpuscles  may  be  readily  distinguished  in  the  blood  cir- 
culating through  the  small  vessels  of  the  Frog's  foot;  and  it  is  then  observable 
that  they  occupy  the  exterior  of  the  current,  where  the  motion  of  the  fluid  is 
slow,  whilst  the  red  corpuscles  move  rapidly  through  the  centre  of  the  tube 
(Fig.  56).  The  Colourless  corpuscles,  indeed  often  show  a  disposition  to  adhere 
to  the  walls  of  the  vessels ;  which  is  manifestly  increased  on  the  application  of  an 
irritant.  Hence  the  idea  naturally  arises,  that  (to  use  the  words  of  Mr.  Wharton 
Jones)  "  there  is  some  reciprocal  relation  between  the  colourless  corpuscles,  and 
the  parts  outside  the  vessels,  in  the  process  of  nutrition.  Of  the  nature  of  this 
relation  we  have  no  certain  knowledge ;  but  if  the  Red  corpuscles  discharge  the 
function  which  has  been  suggested  for  them  (§  160),  of  preparing  the  nutrient 
material  for  muscle  and  nerve,  it  may  not  be  deemed  improbable  that  the  Colour- 
less corpuscles  should  perform  a  similar  office  for  the  other  albuminous  tissues. 
A  very  remarkable  spontaneous  change  of  form  has  been  observed  by  Mr.  Whar- 
ton Jones  to  take  place  in  the  Colourless  corpuscles  whilst  being  examined  under 
the  microscope;1  and  this  not  only  in  the  blood  of  Man,  but  in  that  of  animals 
1  "Philosophical  Transactions,"  1846,  pp.  64,  71,  90,  &c. 


180 


OP  THE   BLOOD; 


FIG.  56. 


A  small  Venous  trunk,  a,  from  the  Web 
of  the  Frog's  foot ;  b,  6,  cells  of  pavement- 
epithelium,  containing  nuclei.  In  the  space 
between  the  current  of  oval  Blood-corpus- 
cles, and  the  walls  of  the  vessel,  the  round 
transparent  colourless  corpuscles  are  seen. 


of  all  the  Vertebrated  classes,  as  also  in  that  of  Invertebrata,  whose  only  cor- 
puscles are  of  this  character  (§  165).    From 
some  point  of  their  circumference  a  pro- 
trusion  of  the   cell-wall   takes  place,  the 
form    of    which    seems   quite    indefinite; 
soon  afterwards,  another  protrusion  may  be 
seen  to  arise  from  another  part  of  the  cell, 
the  first  being  either  drawn-in   again,  or 
remaining  as  it  was;    and  thus  the  confi- 
guration of  the  corpuscles  may  be  seen  to 
undergo  several  changes  before  the  process 
finally   ceases,    and   this   whilst   they   are 
floating  in  their  own  serum,  and  the  red 
corpuscles  are  lying  quite  passive  in  their 
immediate   vicinity.      These   changes   of 
form  (which  bear  a  striking  resemblance 
to  those  of  the  Proteus-cell)  are  affirmed 
by  Dr.  Davaine1  to  be  visible  even  whilst 
the  blood  is  circulating  through  the  ves- 
sels, in  those  colourless  corpuscles  which 
are  retarded  by  attraction  to  their  walls. 

165.  The  proportion  which  the  White  or 
Colourless  corpuscles  bear  to  the  Red,  is 
very  small  in  the  blood  of  Man  and  the 
higher  Vertebrata ;  being,  in  the  state  of 
health,  according  to  the  estimate  of  Moleschott  (which  is  confirmed  by  Kb'lli- 
ker2)  not  more  than  2-55  to  1000.  It  may  undergo  a  great  increase  in 
disease,  however,  as  will  be  shown  hereafter  (§  191).  In  the  oviparous  Verte- 
brata, the  proportion  is  higher;  thus  it  has  been  observed  by  Wagner3  to  be  as 
1 : 16  in  the  blood  of  a  Frog  examined  in  February,  and  as  1 : 6  in  similar  blood 
examined  in  August.  In  one  Vertebrated  animal,  the  Amphioxus,  the  Red  cor- 
puscles are  wanting  altogether,  their  place  in  the  circulating  blood  being  taken  by 
the  Colourless.  And  in  the  Invertebrate  series  generally,  the  corpuscles  of  the 
circulating  fluid  correspond  rather  to  the  colourless  corpuscles  of  the  Blood  of 
Vertebrata,  and  to  the  corpuscles  of  Lymph  and  Chyle  (which  may  be  regarded 
as  the  same  bodies  in  an  earlier  stage  of  development),  than  they  do  to  the  red 
corpuscles,  which  are  peculiar  to  Vertebrata.4  Thus,  in  one  of  its  most  charac- 
teristic features,  the  Blood  of  Invertebrata  (and  of  Amphioxus)  may  be  likened 
rather  to  the  Lymph  and  Chyle  of  Vertebrated  animals  than  to  their  Blood;  and 
this  resemblance  is  strengthened  by  the  fact,  that  there  is  no  distinction  in  tho 
former  between  the  absorbent  and  the  sanguiferous  vessels,  which,  in  the  latter 
contain  the  nutritious  fluid  in  its  earlier  and  in  its  latter  stages  of  development 
Moreover,  the  earliest  blood-corpuscles  of  the  embryo  of  even  the  highest  Ver- 
tebrata are  colourless ;  and  long  after  the  blood  has  acquired  ''ts  characteristic  hue 
from  the  development  of  red  corpuscles,  the  colourles?  ,/puscles  bear  a  very 
large  proportion  to  the  red,  so  as  even  to  equal  them  ii*  number  (as  the  author  is 
informed  by  Mr.  Gulliver)  in  the  blood  of  foetal  Deer,  an  inch  and  a  half  long, 
and  absolutely  to  preponderate  in  the  blood  of  still  smaller  embryoes. 

166.  There  can  be  no  doubt  that  both  the  Red  and  the  Colourless  corpuscles 
have,  like  other  Cells,  a  definite  term  of  life ;  and  that,  whilst  some  are  undergo- 

;  "  M4moires  de  la  Societe*  de  Biologie,"  torn.  ii.  pp.  103 — 5. 

s  "  Manual  of  Human  Histology,"  (Sydenham  Society's  edition),  vol.  ii.  p.  330. 

*  "Elements  of  Physiology,"  translated  by  Dr.  Willis,  p.  246. 

*  See  Mr.  Wharton  Jones's  Memoirs  on  '  the  Blood  Corpuscle  considered  in  its  different 
Phases  of  Development  in  the  Animal  Series,'  in  the  "  Philos.  Trans.,"  1846 ;  also  "  Princ. 
tf  Comp.  Phys.,"  4th  ed.  $$  379—382. 


ITS   PHYSICAL,  CHEMICAL,  AND    STRUCTURAL   CHARACTERS.  181 

ing  disintegration,  others  are  in  a  state  of  advancing  development  to  supply  their 
places,  so  that  the  entire  mass  of  both  is  undergoing  continual  change.  That  a 
new  production  of  Red  corpuscles  may  take  place  with  considerable  rapidity,  we 
have  evidence  in  the  rapid  restoration  of  their  normal  proportion  after  it  has 
been  lowered  by  haemorrhage  (§  178),  and  in  the  speedy  increase  which  may  be  , 
effected  in  their  amount  in  blood  in  which  they  have  been  excessively  diminished 
by  disease  (§  190);  this  being  especially  promoted  by  the  administration  of  Iron, 
and  by  a  generous  diet.  On  the  other  hand,  various  appearances  indicative  of 
degeneration  may  be  seen  in  the  Red  corpucles ;  and  this  especially  in  the  blood 
of  the  Oviparous  Verterbrata,  which  usually  contains  corpuscles  almost  destitute 
of  colour,  and  having  a  shrunken  or  eroded  aspect,  their  nuclei,  however,  present- 
ing a  remarkable  distinctness.  That,  under  certain  circumstances,  such  a  degen- 
erating process  takes  place  with  great  rapidity  in  the  blood  which  circulates  through 
the  Spleen,  may  be  ascertained  almost  beyond  a  doubt  (§§  142,  in,  184).  Of 
the  ordinary  duration,  however,  of  the  life  of  either  the  Red  or  the  Colourless 
corpuscles,  we  have  not  at  present  any  means  of  making  an  approximative  estimate. 
The  question  now  arises,  in  what  manner  the  two  classes  of  Corpuscles  are  respec- 
tively developed,  and  whether  they  have  any  relationship  to  each  other. 

167.  That  the  fully-developed  Red  corpuscles,,  when  ceasing  to  exist  as  such, 
do  not  give  origin  to  new  corpuscles  of  the  same  kind,  may  now  be  asserted  (not- 
withstanding the  statements  of  former  observers)  to  be  the  concurrent  opinion  of 
nearly  all  who  have  in  recent  times  specially  devoted  themselves  to  this  inquiry. 
The  first  Rod  corpuscles  unquestionably  have  their  origin,  like  the  original  cells 
of  the  solid  tissues,  in  the  primordial  cells  of  the  germinal  structure ;  and  it  is 
in  the  so-called  *  vascular  layer '  of  the  i  blastodermic  vesicle '  (CHAP.  XVI.  Sect.  4), 
and  in  the  mass  of  cells  which  constitutes  the  rudiment  of  the  heart,  that  this 
metamorphosis  seems  first  to  take  place.  The  situation  of  the  heart,  and  the 
course  of  the  principal  trunks  of  the  'vascular  area/  are  early  marked-out  by 
the  peculiar  disposition  of  the  aggregations  of  cells  from  which  these  organs  are 
to  be  developed ;  and  whilst  the  outer  portions  of  these  aggregations  are  trans- 
formed into  the  walls  of  the  respective  cavities,  the  inner  portions  seem  partly  to 
deliquesce,  and  partly  to  remain 

as  isolated  cells  floating  in  the  [Fie.  57. 

liquid  thus  produced.  These 
isolated  cells  are  the  first  blood- 
corpuscles  ;  and  the  following 
account  of  them  is  given  by  Mr. 
Paget,1  who  has  made  them  the 
subject  of  careful  study.  "  As 
described  by  Vogt,  Kb' Hiker, 
and  Cramer,  they  are  large 
colourless  vesicular  spherical 
cells,  full  of  yellowish  particles 
of  a  substance  like  fatty  matter ; 
many  of  which  particles  are 
quadrangular  and  flattened,  and 
have  been  called  stearine-plates 
(Fig.  57),  though  they  are  not 
proved  to  consist  of  that  or  any 
other  unmixed  fatty  substance. 

Among  these  particles  each  cell  has  a  central  nucleus,  which,  however,  is  at 
first  much  obscured  by  them.  The  development  of  these  embryo-cells  into  the 
complete  form  of  the  corpuscles  is  effected  by  the  gradual  clearing-up,  as  if  by 

a  This  account  is  cited  from  Messrs.  Kirkes  and  Paget's  "  Hand-book  of  Physiology," 
(pp.  62 — 5  Am.  Ed.),  in  which  it  appears  as  an  abstract  of  a  part  of  Mr.  Paget's  Lectures  on 
tbe  •  Life  of  the  Blood,'  delivered  at  the  College  of  Surgeons  in  1848. 


D  E 

Development  of  the  first  set  of  red  corpuscles  in  the 
blood  of  the  Batrachian  larva.  A.  An  embryo-cell,  filled 
with  fatty-looking  particles.  B,  c,  D,  and  E.  Successive 
stages  in  the  transition  of  the  embryo-cell  to  a  blood-cor- 
puscle, as  described  in  the  text.  F.  A  fully-formed  blood- 
corpuscle.] 


182  OF    THE 

division  and  liquefaction,  of  the  contained  particles,  the  acquirement  of  blood- 
colour  and  of  the  elliptical  form,  the  flattening  of  the  cell,  and  the  more  promi- 
nent appearance  of  the  nucleus."     The  process  ap- 
FlG-  58«  pears  to  be  essentially  the  same  in  the  Fish,  the  Rep- 

tile, and  the  Bird ;  but  it  takes  place  too  rapidly  in 
/j2\  a,          tne    latter   class  for  its  stages    to    be    clearly  distin- 

^^^  guished ;  whilst  in  the  tadpole  the  changes  occur  so 
:<  I  VB  slowly  that  they  can  be  traced  in  the  blood  even  while 
it  circulates.  —  The  history  of  the  development  of 
the  first  red  corpuscles  in  Mammalia  is  nearly  the 
same ;  but  a  binary  multiplication  of  these  bodies  by 
subdivision  (Fig.  58)  has  been  observed  in  them  by 
Prof.  Kolliker '  and  others,  which  has  not  been  notice'd 
elsewhere.  In  watching  the  stages  of  this  process  it 
*s  seen  tna^  *^e  partition  of  the  nucleus  takes  place 
completely,  before  that  of  the  cell  itself  has  com- 
menced.  The  blood-corpuscles  of  the  Human  embryo 

tbus  f°™e?'  r  iescribed  ^ Mr-  paset  as  "™- 

tri-nucleated  large  colourless  cular,  thickly  disc-shaped,  full-coloured,  and,  on  an 

elongated  blood-cells,in  differ-  average,  about  1 -2500th  of  an  inch  in  diameter;  their 

ent   stages   of   subdivision ;  nuclei,  which   are   about  l-5000th    of    an    inch    in 

I,    b,   spherical    blood-cells,  Diameter,  are  central,  circular,  very  little  prominent 

one  of  them  having  a  nucleus  f             £    ,£ 

beginning   to   divide;   c,   a     on  the  surfaces  of  the  cell,  and  apparently  slightly 

smaller  cell  of  the  same  kind,     granular  or  tuberculated.     In  a  few  instances,  cells 

are  found  with  two  nuclei ;  and  such  cells  are  usually 

large  and  elliptical,  with  one  of  the  nuclei  near  each  end  of  the  long  axis."  — 
When  the  Liver  begins  to  be  formed,  this  multiplication  of  blood-cells  in  the  entire 
mass  of  the  blood  ceases,  and  in  a  short  time  all  trace  of  the  development  of  the 
red  out  of  the  original  colourless  formative  cells  is  lost;  whilst,  on  the  other 
hand,  there  takes  place  in  the  vessels  of  the  liver  a  new  production  of  colourless 
nucleated  cells,  which  are  formed  around  free  nuclei,  and  which  undergo  a  gra- 
dual change  (by  the  development  of  colouring  matter  in  their  interior)  into  red 
nucleated  cells  resembling  those  of  the  first  brood.  According  to  Kolliker  (Op. 
cit.  p.  343),  this  new  formation  of  blood-corpuscles  in  the  liver  continues  to 
take  place  during  the  whole  of  the  foetal  life  of  Mammalia,  as  in  Birds  during 
incubation  (§  132).  Whether  these  nucleated  cells  themselves  undergo  a  trans- 
formation into  the  non-nucleated  discs  characteristic  of  Mammalia,  which  consti- 
tute a  gradually-increasing  proportion  of  the  corpuscular  components  of  the  blood 
during  the  latter  period  of  embryonic  life,  or  whether  these  are  formed  only 
by  the  metamorphosis  of  lymph-corpuscles,  has  not  yet  been  ascertained. 

168.  That  after  the  Chyle  and  Lymph  have  begun  to  flow  into  the  circulating 
current,  the  continued  generation  of  Red  corpuscles  is  due  to  the  progressive  me- 
tamorphosis of  the  corpuscles  of  those  fluids,  is  an  opinion  which  has  come  of 
late  to  be  very  generally  received  amongst  Physiologists ;  it  may  be  found,  how- 
ever, to  require  some  modification.  It  rests  upon  facts  of  three  different  orders  : 
— 1st,  the  presence,  in  the  blood  of  oviparous  Vertebrata,  of  corpuscles  exhibit- 
ing what  appear  to  be  intermediate  gradations  of  development  between  Lymph- 
corpuscles  and  their  nucleated  Red  corpuscles;  and  this  especially  in  blood  in 
which  an  unusually  rapid  development  of  red  corpuscles  is  taking  place,  to  make- 
up for  previous  loss;  2nd,  frequent  ruddiness  in  the  hue  of  the  fluid  of  the 
Thoracic  duct,  which  seems  to  depend  upon  the  incipient  development  of  Haema- 
tine  in  some  of  its  floating  corpuscles ;  and  3rd,  the  progressive  transition  from 
one  form  to  the  other,  which  may  be  observed  in  the  ascending  scale  of  animal 

3  See  his  Memoir,  '  Ueber  die  Bliitkorperchen  eines  menschlichen  Embryo,'  &c.,  in 
"  Zeitschrift  fiir  ration.  Med.,"  1846;  and  his  "  Manual  of  Human  Histology"  (Sydenham 
Society's  edition),  p.  342. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.        183 

existence.  To  these  considerations  may  be  added,  the  absence  of  any  other 
mode  of  production  that  can  be  suggested  ;  since  the  idea  of  the  self-multipli- 
cation of  the  Red  corpuscles  is  almost  certainly  erroneous,  and  no  special  organ 
can  be  assigned  as  the  seat  of  their  generation.  As  to  the  modes  in  which  the 
non-nucleated  Red  corpuscles  of  Mammalian  blood  are  produced  from  the  Colour- 
less or  Lymph-corpuscles,  there  are  two  very  dissimilar  opinions  ;  the  entire 
lymph-corpuscle  being  thus  metamorphosed  into  the  red,  in  the  opinion  of  some, 
whilst  its  nucleus  alone,  set-free  by  the  dissolution  of  the  surrounding  cell, 
becomes,  in  the  opinion  of  others,  the  ultimate  red  corpuscle.  The  transition- 
stages  of  the  process,  as  they  are  seen  in  the  Human  blood,  are  thus  described 
by  Mr.  Paget,1  who  adopts  the  first  of  these  opinions.  "The  white  corpuscle, 
at  first  tuberculated,  containing  many  granules,  and  darkly  shaded  (Fig.  59), 


Development  of  human  lymph  and  chyle  corpuscles  into  red  corpuscles  of  Blood.  A.  A 
lymph,  or  white  blood-corpuscle.  B.  The  same,  in  process  of  conversion  into  a  red  corpuscle. 
c.  A  lymph-corpuscle,  with  the  cell-wall  raised  up  around  it  by  the  action  of  water.  D.  A 
lyuiph-corpuscle,  from  which  the  granules  have  almost  disappeared.  E.  A  lymph-corpuscle,  ac- 
quiring color;  a  single  granule,  like  a  nucleus,  remains.  F.  A  red  corpuscle,  fully  developed.] 

becomes  smoother,  paler,  less  granular,  and  more  dimly-shaded  or  nebulous. 
In  these  stages  the  cell-wall  may  be  easily  raised  from  its  contents  by  the  con- 
tact and  penetration  of  acetic  acid,  or  by  the  longer  action  of  water ;  and,  accord- 
ing to  the  stage  of  development,  so  are  the  various  appearances  which  the  con- 
tents of  the  cell  thus  acted-on  present.  In  the  regular  progress  of  development, 
it  becomes  at  length  impossible  to  raise  the  cell-wall  from  its  contents.  Then 
the  corpuscles  acquire  a  pale  tinge  of  blood-colour;  and  this  always  coincides 
with  the  softening  of  the  shadows  which  before  made  them  look  nebulous,  and 
with  the  final  vanishing  of  all  the  granules,  with  the  exception  sometimes  of 
one,  which  remains  some  time  longer  like  a  shining  particle  in  the  corpuscle,  and 
has  probably  been  often  mistaken  for  a  nucleus.  The  blood-colour  now  deepens, 
and  at  the  same  rate  the  corpuscles  become  smooth  and  uniform ;  biconcave, 
having  previously  changed  the  nearly  spherical  form  for  a  lenticular  or  flattened 
one;  smaller,  apparently  by  condensation  of  their  substance,  for  at  the  same 
time  they  become  less  amenable  to  the  influence  of  water;  more  liable  to  corru- 
gation and  to  collect  in  clusters ;  and  heavier,  so  that  the  smallest  and  fullest- 
coloured  corpuscles  always  lie  deepest  in  the  field.  Thus  the  most  developed 
state  of  the  Mammalian  red  corpuscles  appears  to  be  that  in  which  they  are  full- 
coloured,  circular,  biconcave,  small,  uniform,  and  heavy ;  this  is  also  the  state  in 
which  they  appear  to  live  the  longer  and  most  active  portion  of  their  lives."  On 
the  other  hand,  Mr.  Wharton  Jones  has  adduced  very  cogent  evidence,  derived 
chiefly  from  a  comparison  of  the  sizes  of  the  true  red  corpuscles  of  different 
Mammals,  with  those  of  the  nuclei  of  the  nucleated  corpuscles  which  their  blood 
contains,  that  the  former  are  the  equivalents  of  the  latter,  in  a  state  of  higher 
1  "  Hand-Book  of  Physiology,"  pp.  65—6,  Am.  Ed. 


184 


OF  THE   BLOOD; 


[Fio.  60. 


Phases  of  the  human 
blood  -  corpuscles  —  after 
Wharton  Jones,  a  and  b, 
granule  cells  in  the  coarse- 
ly and  finely  granulated 
state  ;  c  and  d,  nucleated 
cells;  c,  without  colour, 
and  d,  with  colour;  e,  free 
cellae-fortn  nucleus,  a  per- 
fect red  corpuscle.] 


development)  having  acquired  a  vesicular  character,  and  having  their  interior 
occupied  by  globuline  and  haematine.  This  view  cer- 
tainly harmonizes  well  with  the  fact,  which  can  scarcely 
be  explained  on  the  preceding  hypothesis,  that  the  red 
corpuscles  of  most  Mammalia  are  smaller  (often  very 
much  so)  than  the  nucleated  cells  in  which  they  origi- 
nate1 (Fig.  60). 

169.  Thus,  then,  the  Chyle  and  Lymph  seem  to  be 
continually  supplying,  not  merely  the  pabulum  for  or- 
ganization derived  from  the  food,  whereby  the  compo- 
nents of  the  liquid  part  of  the  blood  are  replenished 
as  fast  as  they  are  withdrawn ;  but  also  the  rudimentary 
corpuscles  which  are  to  be  progressively  metamorphosed 
into  the  coloured  discs  that  float  in  its  current.  —  A  re- 
markable correspondence  has  been  pointed-out  by  Mr. 
Wharton  Jones  (loc.  cit.)  between  the  successive  phases 
presented  by  the  Blood-corpuscles  in  the  animal  series, 
and  those  through  which,  according  to  the  views  above 
stated,  the  Red  corpuscle  passes  in  attaining  its  complete 
form  in  the  highest  animal.  For  in  the  blood  of  the  In- 
vertebrata,  as  in  the  chyle  and  lymph,  and  occasionally  in 
the  blood,  of  Vertebrata,  are  found  f  coarse  granule- 
cells/  which  seem  to  be  in  the  first  stage  of  development, 
and  '  fine  Granule-cells/  which  may  be  regarded  as  in  the  second.  These  lead-on  to 
the  '  colourless  nucleated  cell/  which  is  the  highest  form  presented  by  the  corpus- 
cles in  Invertebrated  animals,  but  is,  as  we  have  seen,  a  mere  transitional  stage  of 
brief  duration  in  those  of  Vertebrata.  The  *  coloured  nucleated  cell/  again,  is  the 
highest  form  of  red  corpuscle  in  the  Oviparous  Vertebrata ;  and  this  corresponds 
with  the  first-formed  red  corpuscle  of  embryonic  Mammalia.  The  '  red  corpuscles' 
of  the  fully-formed  blood  of  the  latter  are  to  be  regarded  as  exhibiting  that  highest 
phase  of  development,  in  which  the  nucleus,  having  escaped  from  its  parent-cell, 
itself  assumes  much  of  the  cellular  character.  In  its  early  state,  this  '  cellaa-form 
nucleus '  is  uncoloured ;  but  it  so  soon  acquires  the  red-hue,  that  it  is  rarely  met- 
with  in  its  earlier  state.  —  Fully  admitting,  however,  that,  in  one  mode  or  the 
other,  the  Red  corpuscle  is  originally  developed  from  the  lymph-globule,  and  that 
this  is  also  the  source  of  the  Colourless  corpuscle,  still  it  would  seem  quite  possible, 
that  the  Red  and  the  Colourless  corpuscles  are  to  be  regarded  as  two  distinct  and 
complete  forms,  neither  being  capable  of  metamorphosis  into  the  other,  and  each 
having  a  specific  purpose  to  serve  in  the  economy.  For,  so  far  as  can  be  judged 
by  appearances,  there  is  a  close  correspondence  between  the  Colourless  corpuscles 
and  the  corpuscles  of  those  "Vascular  Glands  "  which  are  developed  in  connection 
with  the  Absorbent  and  Sanguiferous  systems,  and  which  seem  to  have  it  for  their 
office  to  assist  in  elaborating  the  nutrient  materials  of  the  blood  (§§  148,  149). 
And  there  are  many  indications,  as  will  hereafter  appear,  that  their  function  is  not' 
dissimilar;  whilst,  on  the  other  hand,  there  is  no  correspondence  between  the 
Red  and  the  Colourless  corpuscles,  either  as  to  their  proportionate  development, 
or  as  to  their  relations  to  the  system  generally  in  health  and  disease  (§§  190, 
191).  —  It  may  be  surmised,  then,  that  if  the  principal  part  of  the  lymph-glo-  j 
bules  really  go-on  to  be  developed  into  Red  corpuscles,  a  part  may  undergo  a  \ 
different  course  of  evolution  and  may  become  Colourless  corpuscles  of  the  blood ; 
and  that,  having  once  acquired  the  latter  condition,  they  do  not  pass  beyond  it, 
but  continue  to  present  it  during  their  remaining  term  of  life.  Such  a  diverse 
mode  of  evolution  from  germs  that  appear  to  be  dissimilar,  cannot  be  thought  in 

1  See  Philosophical  Transactions,"  1846,  pp.  75 — 79.  —  Mr.  Wharton  Jones's  views  on 
this  point  have  been  adopted  by  Messrs.  Busk  and  Huxley ;  see  their  translation  of  Prof. 
Kolliker's  "Human  Histology"  (Sydenhara  Society's  edition),  vol.  ii.  p.  347,  note:  aud 
"  Quart.  Journ.  of  Microsc.  Science,"  vol.  i.  p.  145. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.         185 

itself  improbable,  when  it  is  borne  in  mind  that  all  the  tissues  have  their  origin, 
directly  or  indirectly,  in  the  cells  of  the  embryonic  mass,  among  which  not  the 
slightest  difference  can  be  observed;  and  that,  whatever  is  to  be  the  ultimate 
destination  of  cells  at  any  period  of  life,  their  early  aspect  is  for  the  most  part 
extremely  uniform. 

170.  Composition  of  the  Blood.  —  The  principal  constituents  of  the  Blood 
having  been  thus  separately  described,  we  have  now  to  inquire  into  the  mode  in 
which  they  are  associated  in  the  liquid  as  a  whole,  and  the  proportions  in  which 
they  severally  present  themselves.  These  are  subject,  even  within  the  limits  of 
health,  to  considerable  variations  ;  some  of  which  seem  to  depend  upon  the  con- 
stitution of  the  individual,  his  diet,  mode  of  life,  &c.  ;  whilst  others  are  probably 
referable  to  the  period  at  which  the  last  meal  was  taken,  and  the  amount  of 
bodily  exertion  made  within  a  short  time  previous  to  the  analysis.  Hence  no 
single  analysis  could  represent  the  average  composition  of  the  blood,  even  if  it 
were  itself  chemically  accurate;  but  there  are  difficulties  in  the  way  of  quanti- 
tatively determining  with  precision  the  several  components  of  the  blood,  which 
interpose  a  new  source  of  uncertainty  and  error.1  Perhaps  in  the  present  state 

1  The  marked  discrepancy  observable  between  the  results  obtained  by  different  analysts, 
especially  in  regard  to  the  relative  proportions  of  albumen  and  corpuscles,  arises  in  great 
degree  from  the  difference  of  the  methods  of  analysis  employed,  as  has  been  recently  proved 
by  M.  Gorup-Besanez  ("  Journ.  fiir  prakt.  Chem.,"  band  1.  p.  346).  For  he  found  that 
•when  four  samples  of  the  same  blood  were  examined  by  the  methods  adopted  by  four  dif- 
ferent experimenters  respectively,  the  results  were  as  follows. 

The  first  specimen  was  the  blood  of  a  vigorous  man  fifty  years  old  :  — 


HKle. 

Water  ..............................  796-93            796-93            796-93  796-93 

Solid  matters  ....................  203-07            203-07            203-07  203-07 

Fibrin  ..............................       1-95                1-95                1-95  1-95 

Corpuscles  ........................  115-16            117-82            103-23  103-23 

Albumen  .........................     58-82              63-87              50-84  70-75 

Extractive  matter  and  salts..     27-14              1943              47-05  27-14 

The  second  specimen  was  from  a  robust  man  twenty  years  old  :  — 


Water  .............................  783-63  783-63  783-63  783-63 

Solid  matters  .  ...................  216-37  216-37  216-37  216-37 

Fibrin  ...............  .  ..............  1-56  1-56  1-56  1.56 

Corpuscles  ........................  113-54  131-52  115-12  115-12 

Albumen  ..........................  64-32  65-91  51-76  62-74 

Extractive  matter  and  salts  .  36-95  17-38  47-93  36-95 

As  the  greater  number  of  results  hereafter  to  be  cited,  have  been  obtained  by  the 
method  of  MM.  Prevost  and  Dumas,  which  has  been  followed,  with  slight  modifications, 
by  MM.  Andral  and  Gavarret  ("Essai  d'Hsematologie  Pathologique"),  and  by  MM.  Bee- 
querel  and  Rodier  ("  Recherches  sur  la  Composition  du  Sang,"  &c.),  it  will  be  advan- 
tageous here  to  describe  it.  —  The  blood  which  is  being  drawn  for  analysis,  is  received  into 
two  diiferent  vessels,  the  first  and  the  last  quarters  of  the  whole  amount  into  one,  and  the 
&econd  and  third  quarters  into  the  other;  in  this  manner,  the  similarity  of  the  two  quan- 
tities is  secured  as  far  as  possible.  The  blood  in  one  vessel  (A)  is  allowed  to  coagulate 
spontaneously  ;  that  contained  in  the  other  (B)  is  beaten  with  a  small  rod  in  order  to  sepa- 
rate the  fibrin.  When  the  coagulation  has  fully  taken  place  in  A,  the  serum  is  carefully 
separated  from  the  crassamentum  ;  and  there  are  then  dried  and  weighed,  —  1.  The  Fibrin 
obtained  by  the  rod  (B)  ;  —  2.  The  entire  Crassamentum  (A)  ;  —  3.  The  Serum  (A).  The 
weight  of  the  separated  fibrin  gives  the  amount  of  it  contained  in  the  clot.  The  weight 
of  the  dried  residue  of  the  serum  gives  the  proportion  of  its  solid  matter  to  its  water. 
The  quantity  of  water  driven-off  from  the  clot  in  drying,  gives  the  amount  of  serum  it 
contained  ;  from  which  may  be  estimated  the  quantity  of  the  solids  of  the  serum  contained 
in  the  crassamentum.  Hence  by  deducting  from  the  weight  of  the  whole  dried  clot,  first 
the  weight  of  the  fibrin  separated  by  stirring,  and  then  that  of  the  solid  matter  of  the 
serum  as  obtained  by  calculation,  we  obtain  as  a  residue  the  weight  of  the  corpuscles.  In 
order  to  ascertain  the  whole  amount  of  solid  matter  in  the  serum,  that  which  was  ascer- 
tained by  calculation  to  exist  in  the  coagulum,  must  be  added  to  that  which  was  obtained 


186  OF   THE   BLOOD; 

of  our  knowledge,  it  is  impossible  to  arrive  at  any  other  than  an  approximative 
estimate  of  their  respective  amounts;  and  this  may  be  best  founded  on  the  com- 
parative analyses  of  the  Corpuscles  and  Liquor  Sanguinis  already  cited  from 
Prof.  Lehmann  (§  160);  it  being  assumed  that  the  moist  Corpuscles  form  half 
of  the  entire  volume  of  the  blood.  This  is  probably  rather  beneath  than  above 
the  actual  average,  which  he  considers  to  be  512  parts  in  1000 ;  the  limits  of 
variation  in  health,  however,  are  about  40  parts  on  either  side.  By  halving  the 
numbers  in  the  preceding  table,  therefore,  and  adding  together  those  which  refer 
to  constituents  of  the  same  character,  we  obtain  the  following  results : — 

Water 795-45 

Solid  residue  204-55 

Fibrin  2-025 

formisrles      \H8ematin   8-375 

/Globulin  and  cell-membrane  141-110 

Albumen 39-420 

Fatty  matters 2-015 

Extractive  matters 3-270 

Mineral  substances,  exclusive  of  iron 8-335 

Chlorine 2-665 

Sulphuric  acid -090 

Phosphoric  acid -663 

Potassium  1-825 

Sodium 2-197 

Oxygen -535 

Phosphate  of  Lime -212 

Phosphate  of  Magnesia  -148 

171.  The  principal  constituents  of  the  Blood  having  been  already  described, 
it  only  remains  to  notice  those  of  less  prominent  importance.  Under  the  general 
head  of  Fatty  Matters  are  included  several  different  kinds  of  fat,  some  of  which 
present  very  definite  characters,  whilst  the  nature  of  others  has  not  yet  been 
precisely  determined.  A  considerable  part  of  the  whole  amount  is  formed  by 
the  saponifiable  fats,  which,  in  the  human  subject,  are  Margarin  and  Olein ;  and 
it  must  be  in  these  that  the  chief  increase  occurs,  when  the  amount  of  fatty 
matter  in  the  blood  is  temporarily  augmented  by  the  entrance  of  oleaginous 
chyle  (§  177).  The  proportion  of  phosphorized  fat,  which  seems  to  form  an 
essential  constituent  of  the  Corpuscles  (§  160),  will  probably  vary  in  part  with 
their  amount;  but  the  range  of  variation  seems  to  be  too  wide  to  admit  of  the 

from  the  separated  serum.  Finally,  the  proportions  of  organic  and  of  inorganic  matter  in 
the  solids  of  the  serum  are  ascertained  by  incinerating  them  in  a  crucible ;  by  which  the 
whole  of  the  former  will  be  driven-off,  the  latter  being  left. 

Both  of  the  foregoing  methods,  like  most  others,  are  open  to  the  objection,  that  the 
albuminous  and  other  constituents  of  the  serum  are  reckoned  in  the  calculation  as  being 
equally  present  in  the  whole  water  of  the  blood  Now  as  the  moist  Corpuscles,  according 
to  Schmidt,  constitute  fully  half  the  mass  of  the  blood,  and  as  they  do  not  contain  the 
albuminous  elements  of  the  serum,  and  have  salines  peculiar  to  themselves,  it  is  obvious 
that  the  constituents  of  the  Serum  will  be  estimated  far  too  high,  and  the  residue,  which 
expresses  the  solid  matter  of  the  Corpuscles,  as  much  too  low.  Moreover,  this  method  of 
analysis  gives  no  account  whatever  of  the  Salts  contained  in  the  Corpuscles,  which,  as  we 
have  seen  (g  160),  are  very  different  from  those  of  the  Serum;  and  these  can  only  be 
determined  by  the  incineration  of  the  whole  mass  of  the  blood.  —  For  an  account  of  the 
methods  of  analysing  the  blood,  employed  by  Berzelius,  Denis,  and  Simon,  see  the 
"Animal  Chemistry"  of  the  last  named  author  (p.  143,  et  seq.,  American  Edition);  and 
for  a  critical  comparison  of  these  and  other  methods  more  recently  devised,  see  Prof. 
Lehmann's  "  Physiological  Chemistry"  (Cavendish  Society's  Ed.),  vol.  ii.  pp.  213,  et  seq 
The  method  of  Schmidt,  which  is  approved  by  the  last-named  authority,  is  based  on  very 
ingenious  investigations  and  calculations,  by  which  he  has  shown  that  if  the  weight  of  the 
dry  corpuscles,  obtained  by  the  method  of  Prevost  and  Dumas,  be  multiplied  by  4,  it  will 
give  the  weight  of  the  moist  corpuscles. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.         187 

difference  being  fully  accounted-for  in  this  manner.  The  presence  of  Cholesterin 
seems  to  be  constant;  but  it,  too,  exhibits  a  considerable  diversity  in  its  amount, 
probably  depending  upon  the  relations  between  the  biliary  secretion  and  the  res- 
piratory process.  Of  the  fatty  substance  termed  Serolin,  the  quantity  is  always 
very  minute,  and  it  is  sometimes  inappreciable.  —  The  following  table  represents 
the  mean,  maximum,  and  minimum  amounts  of  these  fatty  substances  in  the 
healthy  blood  of  the  male  (the  proportion  in  that  of  the  female  being  almost  pre« 
cisely  similar),  according  to  the  analyses  of  MM.  Becquerel  and  Rodier. 

Mean.  '  Max.  Min. 

Saponified  fat 1-004  2-000  -700 

Phosphorized  fat -488  1-000  -270 

Cholesterin -088  -175  030 

Serolin  -020  -080  inappreciable. 

The  source  of  the  peculiar  odour  of  the  blood,  is  probably  a  volatile  fatty  acid, 
too  minute  in  its  amount  to  admit  of  being  separately  estimated.  This  odour 
may  be  made  much  more  apparent  by  treating  the  blood  with  sulphuric  acid,  even 
after  it  has  been  long  dried ;  and  in  all  those  animals  which  are  readily  dis- 
tinguishable by  their  odorous  emanations,  it  may  thus  be  made  so  perceptible  as 
to  admit  of  their  blood  being  distinguished  (at  least  by  an  individual  possessed 
of  a  delicate  sense  of  smell)  through  its  scent  alone.  Of  this  test,  use  has  been 
made  with  great  advantage  in  juridical  investigations.1 

172.  Under  the  vague  term  Extractive,  have  been  included  many  different 
substances  which  normally  present  themselves  in  only  very  small  quantity,  and 
which  are  consequently  very  difficult  of  detection ;  but  which  are  extremely  im- 
portant in  a  physiological  point  of  view,  as  the  chief  '  factors'  (to  use  the  ap- 
propriate designation  of  Prof.  Lehmann)  in  the  metamorphosis  of  animal  tissue, 
both  progressive  and  retrograde.  Some  of  these,  such  as  the  compounds  which 
have  been  designated  by  Mulder  as  the  binoxide  and  tritoxide  of  protein,  appear 
to  be  histogenetic  substances  in  the  course  of  preparation  for  organization ;  very 
little,  however,  is  certainly  known  respecting  them.  Glutin  (gelatin)  also  has 
been  recently  detected  in  the  blood ;  but  this,  for  the  reasons  already  given  (§  51), 
can  scarcely  be  regarded  as  a  histogenetic  substance,  and  must  have  been  prob- 
ably derived  directly  from  the  food,  and  have  been  waiting  to  be  excreted.  Of 
the  products  of  retrograde  metamorphosis,  however,  which  are  on  their  way  to 
the  excretory  organs,  our  knowledge  is 

much  more  precise ;    and  already  there  FIG.  61. 

have  been  detected  in  the  extractive  the 
principal  components  of  the  biliary  and 
urinary  excretions,  namely,  cholic  acid,2 
urea,  creatine  and  creatinine,  and  uric 
and  hippuric  acids,  and  also  hypoxanthin, 
and  formic,  acetic,  and  lactic  acids.3  — 
Much  attention  has  recently  been  given 
to  the  red  crystals  which  form  in  blood 
after  it  has  been  at  rest  for  some  time, 
and  especially  if  it  have  been  diluted 
with  water.  These  crystals  present  a 
considerable  variety  of  forms  in  different 

i     /TV      ci\         j     j.  j-ir  Blood-Crystals,  (1)  prismatic,  from  Human 

animals  (Fig.  61),  and  at  different  stages  blood>  (2)  fetrahedral,  from  Pig's  blood,  (3) 
Of  decomposition  in  the  blood  of  the  hexagonal  plates,  from  Squirrel's  blood. 

same  animals;  and  they  present  also  very 

1  See  M.  Barruel's  researches  on  this  subject  in  "  Ann.  d'Hygiene,"  &c.  toni.  i.  ii.  x. 

4  The  presence  of  cholic  acid,  in  combination  with  soda,  as  a  normal  ingredient  in  blood, 
eeems  lately  to  have  been  substantiated  by  Enderlin.  See  the  account  of  his  researches, 
*  Cholosaures  Natron  in  Blute,'  in  Schmidt's  Jahrb.  i.  1853. 

8  See  Lehmann's  "  Physiologischeu  Chemie,"  2nd  edit.,  band  ii.  p.  180. 


188 


OF  THE   BLOOD; 


marked  diversities  in  chemical  properties,  some  being  readily  soluble  in  water, 
whilst  others  are  insoluble  in  water  but  soluble  in  acetic  acid,  and  others  are  in- 
soluble either  in  water  or  acetic  acid.  The  reactions  of  some  of  these  crystals 
would  seem  to  indicate  that  they  are  formed,  or  at  least  derived,  from  protein- 
compounds;  but  others  seem  rather  to  consist  of  phosphoric  acid,  in  'conjuga- 
tion' with  an  organic  substance.  The  whole  matter  is  at  present  involved  in 
great  obscurity;  but  it  can  scarcely  be  doubted  that,  whatever  be  the  nature  of 
this  crystalline  substance,  it  is  in  a  state  of  retrograde,  not  of  progressive  meta- 
morphosis.1 Besides  the  foregoing,  the  extractive  of  blood  generally  seems  to 
contain  Sugar  that  is  waiting  for  elimination  by  the  respiratory  process,  this  sub- 
stance being  found  most  abundantly,  however,  in  the  blood  of  the  hepatic  vein, 
vena  cava,  and  pulmonary  artery  (§  154).  As  might  be  expected,  the  propor- 
tion of  sugar  in  the  blood  is  greatly  affected  by  the  diet  of  the  animal  (§  177). — 
The  very  small  amount  in  which  the  Blood-constituents  of  this  class  normally 
present  themselves,  is  readily  accounted-for  by  the  fact,  that  they  are  only  en 
route  between  the  tissues  and  the  excretory  organs  which  are  destined  for  their 
elimination ;  so  that  as  long  as  the  disintegrating  processes  taking  place  in  the 
former  are  balanced  (as  they  should  be)  by  the  activity  of  the  latter,  these  sub- 
stances are  withdrawn  from  the  blood-current  as  fast  as  they  are  introduced  into 
it,  and  no  sensible  accumulation  will  occur.  It  can  scarcely  be  doubted  that  the 
more  attentive  study  of  this  part  of  the  blood,  prosecuted  upon  large  quantities 
at  once,  will  be  attended  with  the  discovery  of  many  facts  that  would  throw  great 
light  upon  the  Chemistry  of  the  histogenetic  operations,  and  of  the  retrograde 
metamorphoses  of  the  effete  materials  of  the  tissues. 

173.  The  list  of  the  Inorganic  Constituents  of  the  Blood,  which  is  given  in 
the  preceding  table  (§  170),  does  not  express  the  mode  in  which  they  are  grouped 
together;  and  it  takes  no  account  of  the  Carbonic  acid,  which  certainly  exists  in 
the  blood  united  with  Alkaline  bases.  The  proportion  which  the  Carbonates 
bear  to  the  Phosphates,  however,  seems  to  be  small  in  Human  blood ;  as  is  shown 
by  the  following  table,  founded  on  the  analysis  of  Verdeil,2  of  the  per-centage 
composition  of  the  ash  of  the  blood,  after  deducting  the  carbon  still  contained 
in  it.  The  corresponding  analyses  of  the  blood  of  the  Dog,  Ox,  Sheep,  and  Pig, 
are  here  given,  to  show  the  remarkable  variation  between  the  relative  amounts 
of  the  Carbonates  and  Phosphates,  in  the  blood  of  Herbivorous  and  Carnivorous 
animals,  which  is  obviously  related  to  the  difference  of  their  diet.  It  will  be 
observed  that  the  proportion  of  Chloride  of  Sodium  exhibits  a  remarkable  con- 
stancy. 


Man. 

Dog. 

1           Ox. 

Sheep. 

Pig. 

A.3 

B.« 

A.' 

B.6 

Chloride  of  Sodium 

61-99 

55-63 

49-85 

50-98 

59-12 

53-71 

57-11 

50-62 

41-31 

49-51 

Soda 

2-03 

6-27 

5-78 

2-02 

13-00 

14-40 

13-33 

13-40 

7-62 

5-33 

Potassa  

12-70 

11-24 

15-16 

19-16 

5-60 

8-76 

5-29 

7-93 

22*21 

18-54 

0-99 

1-26 

0-67 

4-38 

0-47 

0-59 

0-30 

0-82 

1-21 

0-97 

Sulphuric  acid  .... 

1-70 

1-64 

1-71 

1-08 

1-25 

1-16 

1-65 

1-91 

1-74 

1-34 

Phosphoric  acid... 

7-48 

9-74 

12-74 

9-34 

3-40 

3-02 

3-83 

3-41 

1061 

11-48 

Phosphate  of  lime 

3-55 

3-21 

1-32 

3-05 

2-51 

2-32 

2-38     2-68 

2-88 

3-17 

Peroxide  of  iron... 

8-06 

8-68 

12-75 

8-65 

9-00 

8-80 

8-70     9-17 

9-10 

9-52 

Carbonic  acid  

1-43 

0-95 

0-53 

0-37 

6-57 

6-49 

7-09 

6-35 

0-69 

0-36 

1  For  a  recent  summary  of  what  is  known  respecting  it,  see  an  Article  on  'Albuminous 
Crystallization,'  by  Dr.  Sieveking,  in  the  "Brit,  and  For.  Med.-Chir.  Re?.,"  vol.  xii.  p.  348. 
a  "Ann.  der  Chem.  und  Pharm.,"  band  Ixix.  p.  89. 

*  Man,  forty-five  years  old,  suffering  from  weak  digestion. 

4  Woman,  twenty-two  years  old,  sanguineous  temperament. 
After  a  flesh  diet  of  eighteen  days. 

*  After  feeding  for  twenty  days  upon  bread  and  potatoes. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.         189 

174.  We  have  now  to  inquire  into  the  principal  modifications,  which  the  rela- 
tive proportions  of  these  constituents  undergo  in  the  state  of  health,  under  the 
influence  of  varying  conditions  of  the  system;  and  notwithstanding  the  want  of 
absolute  correctness  in  the  analyses  of  which  we  are  at  present  in  possession, 
those  that  are  made  by  similar  methods  give  results  sufficiently  trustworthy  to 
enable  them  to  be  compared  together,  and  thus  to  give  a  tolerably  correct  indi- 
cation of  the  circumstances  which  determine  the  increase  or  diminution  in  the 
principal  components  of  the  Blood.  —  The  first  of  these  modifying  conditions 
which  requires  special  notice,  is  Aye.  During  the  latter  part  of  foetal  life,  the 
blood  is  remarkably  rich  in  solid  contents ;  it  being  in  the  proportion  of  cor- 
puscles (including  iron),  that  the  chief  difference  exists  between  foetal  and 
maternal  blood.  This  appears  from  the  following  comparative  analyses  made  by 
Denis  !  of  the  venous  blood  of  the  mother,  and  of  the  blood  of  the  umbilical 
artery,  which  last  has  been  recently  found  by  Poggiale  (as  might  be  expected)  to 
be  identical  with  that  of  the  body  of  the  foetus. 


Venous  Blood  of  Mother. 

Water 781-0 

Solid  constituents 219-0 

Fibrin 2-4 

Corpuscles  ]39-9 

Albumen 50-0 

Phosphorized  Fat 9-2 

Peroxide  of  Iron 0-8 

Extractive 4-2 

Salts ...  12-5 


Blood  of  Umbilical  Artery. 
701-5 
298-5 

2-2 

222-0 

50-0 

7-5 

2-0 

2-7 
12-1 


The  analyses  of  Poggiale2  give  255-8  parts  of  solid  matter,  of  which  172-2 
parts  were  corpuscles,  and  2  parts  of  peroxide  of  iron,  in  1000  parts  of  foetal 
blood  ;  thus  agreeing  with  those  of  Denis  in  the  main  fact  of  the  excessive  pro- 
portion of  corpuscles  and  iron.  — The  proportion  of  corpuscles  seems  to  remain 
high  for  a  short  time  after  birth ;  but  it  gradually  diminishes ;  and  the  whole 
amount  of  solid  matter  in  the  blood  seems  to  fall  to  its  lowest  point  during  the 
period  of  childhood.  Towards  the  epoch  of  puberty,  however,  the  amount  of 
solid  matter  increases  again,  the  chief  augmentation  being  in  the  corpuscles; 
and  it  remains  at  a  high  standard  during  the  most  vigorous  period  of  adult  life, 
after  which  it  begins  to  decline.  This  is  made  apparent  in  the  following  table, 
deduced  from  the  analyses  of  Denis,  which  are  confirmed  by  those  of  Lecanu 
and  Simon.3 

Solid  Constituents. 
In    5  individuals  between    5  months  and  1 0  years  170 


13 
11 
12 

6 
8 

2 


10  years      and  20 


20 
30 
40 
50 
60 


30 
40 
50 
60 
70 


200 
240 
240 
240 
220 
210 


175.  An  appreciable  difference  exists  between  the  blood  of  the  two  Sexes; 
that  of  the  male  being  richer  in  solid  contents,  and  especially  in  corpuscles,  than 
that  of  the  female.  On  this  point,  the  analyses  of  Lecanu,  Denis,  and  Becquerel 
and  Rodier  are  in  accordance,  notwithstanding  their  mutual  discrepancies ;  as 
the  following  tables  show  : — 

1  "  Recherches  Expe"rimentales  sur  le  Sang  humain,"  and  "  Simon's  Animal  Chemistry,'* 
p.  197,  Am.  Ed. 

*  "  Comptes  Rendus,"  torn.  xxv.  p.  198. 
»  "  Animal  Chemistry,"  p.  198,  Am.  Ed. 


190 


OF  THE   BLOOD; 


BLOOD  OF  MEN. 
Water 

Becquerel  and  Rodier. 
Mean        Max.         Min. 

779-0     800-0     760-0 

Denis. 
Mean        Max.        Min. 
758-0     790-0     733-3 

Lecanu. 
Mean       Max.        Min 
791-9     805-2     778-6 

Solid  constituents 

221-0     240-0    200-0 

242-0     266-7     210-0 

208-1     221-4    194-8 

Fibrin 

2-2         3-5         1-5 

2-5        2-9        2-1 

Corpuscles   

141-1     152-0     131-1 

147-0     187-1     102-0 

69-4      73-0      62-0 

57-5      63-0      52-3 

Fat         

1-6         3-2         1-0 

Extractive  and  > 

6-8        8-0        5-0 

Salts  of  Serum  £ 

BLOOD  OF  WOMEN. 
Water  

791-1     813-0    773-0 

773-0    820-0    750-0 

821-7    853-1     790-3 

Solid  constituents 
Fibrin  

208-9    227-0    187-0 
2-2        2-5        1-8 

227-0    250-0    180-0 
2-7        3-0        2-5 

178-3    209-7     146-9 

Corpuscles 

127-2     137-5     113-0 

138-0     162-4      88-1 

Albumen  

70-5      75-5      65-0 

61-2      66-4      50-0 

Fat  

1-6        2-9        5-0 

Extractive  and  ) 

7-4        8-5        6-2 

Salts  of  Serum  (  ' 

m 

From  these  it  would  appear  that  the  mean  excess  of  the  whole  solid  constituents 
in  the  blood  of  the  male,  above  those  of  the  female,  is  reckoned  by  the  several 
experimenters  at  from  12  to  20  parts  in  1000;  and  that  the  variation  is  the 
greatest  in  the  proportion  of  Corpuscles,  neither  of  the  other  elements  exhibiting 
any  considerable  difference  in  their  amount  in  the  two  sexes.  The  excess  in  the 
solid  constituents  of  the  male  blood  above  those  of  the  female,  is  as  well  marked 
in  the  extreme  as  in  the  mean  results ;  for  the  maxima  in  the  female  do  not  pass 
much  higher  than  the  mean  of  the  male,  whilst  her  minima  fall  far  below  his ; 
en  the  other  hand,  the  maxima  of  the  male  rise  far  higher  than  those  of  the 
female,  whilst  his  minima  scarcely  descend  below  her  mean. 

176.  It  is  obvious,  from  the  extent  of  diversity  shown  in  the  preceding  table, 
fchat  the  proportions  of  the  constituents  must  vary  considerably  with  individual 
Temperament  and  Constitution.     All  the  persons  whose  blood  furnished  the  sub- 
jects of  the  preceding  analysis,  were  (or  considered  themselves  to  be)  in  perfect 
health;  but  their  standard  of  health  could  not  have  been  by  any  means  uniform. 
There  is  no  doubt  that,  in  individuals  of  the  plethoric  pr  *  sanguineous '  tempera- 
ment, the  proportion  of  the  whole  solid  constituents,  and  especially  of  the  cor- 
puscles, is  considerably  greater  than  in  persons  of  the  ( lymphatic '  temperament ; 
and  it  appears  from  the  analysis  of  Lecanu,1  that  the  sexual  difference  in  the 
blood  almost  disappears,  when  the  blood  of  males  and  of  females  of  the  latter 
temperament  is  compared. 

177.  A  considerable  influence  is  exercised  on  the  entire  amount,  and  on  the 
relative  proportions,  of  the  constituents  of  the  Blood,  by  the  previous  ingestion 
of  Food  or  Drink,  and  by  the  Diet  habitually  employed.    The  observations  hitherto 
made  upon  the  first  of  these  points,  however,  are  not  sufficiently  numerous  to 
admit  of  being  generalized;  and  the  chief  points  that  can  be  definitely  stated, 
are  those  which  have  been  substantiated  by  Profrs.  Buchanan  and  R.  D.  Thomp- 
son,2 in  their  examination  of  blood  whose  serum  exhibits  the  'milky'  appearance, 
which,  when  it  occurs  in  health,  is  due  to  the  entrance  of  chyle,  more  rapidly 
than  its  oleaginous  matter  can  be  eliminated  by  the  respiration  or  appropriated 
by  the  tissues.     When  a  full  meal  containing  oily  matter  is  taken  after  a  long 
.fast,  and  a  small  quantity  of  blood  is  drawn  previously  to  the  meal  and  at  inter- 
vals subsequently,  the  serum,  though  quite  limpid  in  the  blood  first  drawn, 
show«  an  incipient  turbidity  about  half  an  hour  afterwards ;  this  turbidity  in- 

*  "Etudes  Chimiques  sur  le  Sang  humain,"  p.  66;  and  Simon's  "Animal  Chemistry," 
vol.  i.  p.  236. 
1  "Medical  Gazette,"  Oct.  10,  1845. 


IT?    PHYSICAL,  CHEMICAL,  AND    STRUCTURAL    CHARACTERS.  101 

creases  for  about  six  hours  subsequently,  after  which  it  usually  begins  to  disap- 
pear. The  period  at  which  the  discoloration  is  the  greatest,  however,  and  the 
length  of  time  during  which  it  continues,  vary  according  to  the  kind  and  quality 
of  the  food,  and  the  state  of  the  digestive  functions.  Neither  starch  nor  sugar, 
nor  proteine-compounds,  alone  or  combined,  occasion  this  opacity  in  the  chyle ; 
but  it  seems  essentially  dependent  upon  an  admixture  of  oleaginous  matter  with 
the  food.  There  are  few  ordinary  meals,  however,  from  which  such  matter  is 
altogether  excluded.  When  such  milky  serum  is  examined  with  the  Microscope, 
the  opacity  is  found  to  be  due  to  the  presence  of  an  immense  number  of  ex- 
ceedingly minute  granules,  resembling  in  appearance  those  which  form  the 
'molecular  base'  of  the  chyle  (§  135).  They  seem  to  be  composed  of  two 
chemically-distinct  substances  ;  for  when  the  milky  serum  is  agitated  with  ether, 
a  part  is  dissolved,  whilst  another  portion  remains  suspended;  and  this  latter  is 
soluble  in  caustic  potass.  The  former,  therefore,  appears  to  be  identical  with 
the  'molecular  base'  of  the  Chyle,  and  to  be  of  an  oily  or  fatty  nature;  whilst 
the  latter  belongs  to  the  protein-compounds.  The  Crassamentum  of  such  blood 
often  exhibits  a  pellucid  fibrinous  crust,  sometimes  interspersed  with  white  dots ; 
and  this  seems  to  consist  of  an  imperfectly-assimilated  protein-compound,  analo- 
gous to  that  found  in  the  serum.  The  quantity  of  this  varies  according  to  the 
amount  of  the  protein-compounds  present  in  the  food. — The  increase  of  saccharine 
matter  in  the  blood  (in  which  it  forms  part  of  the  'extractive'),  after  the  inges- 
tion  of  a  large  quantity  of  saccharine  or  farinaceous  aliment,  has  been  noticed 
by  many  experimenters,  and  has  lately  been  made  the  subject  of  attentive  study 
by  Yon  Becker.1  He  has  found  that  the  blood  o.f  Rabbits  fed  on  carrots,  con- 
tained 0-584  per  cent  of  sugar,  whilst  that  of  rabbits  fed  on  oats  contained  only 
0-109  per  cent;  the  blood  of  the  same  animals  after  24  hours'  starvation,  con- 
tained only  0-045  per  cent;  whilst  as  much  as  1-198  per  cent  was  found  in  the 
blood  of  a  rabbit,  into  whose  food  so  large  an  amount  of  sugar  had  been  intro- 
duced that  it  passed  away  with  the  excrements.  The  proportion  contained,  how- 
over,  in  the  blood  of  Oxen,  Dogs,  and  Cats,  is  far  smaller  than  this ;  being  (ac- 
cording to  the  researches  of  Schmidt)2  from  0.00069  to  0-00074,  0-0015,  and 
0-0021  per  cent  respectively. — It  might  be  fairly  presumed  that  a  temporary 
augmentation  must  take  place  in  the  aqueous  constituent  of  the  blood,  whenever 
any  considerable  quantity  of  liquid  is  ingested;  and  yet  this  augmentation  is  pro- 
bably much  less  considerable,  under  ordinary  circumstances,  than  we  should  at  first 
be  inclined  to  suppose.  For  there  exist  various  provisions  in  the  system  (the  pecu- 
liar Malpighian  apparatus  of  the  Kidneys  being  the  chief)  for  rapidly  freeing 
the  blood  from  any  superfluity  of  water;  and  thus  any  excess  of  fluid  absorbed 
is  speedily  drawn-off  again.  But  further,  it  is  certain  that  when  the  vessels  are 
already  filled,  absorption  does  not  take  place  with  nearly  the  same  readiness  as 
after  long  abstinence  from  liquids  (§  122) ;  the  rate  of  absorption  being  in  great 
degree  governed  by  that  at  which  the  liquid  is  disposed-of.  It  follows,  therefore, 
that  the  absorption  of  even  a  considerable  amount  of  water  within  a  short  time, 
need  not  really  involve  any  great  dilution  of  the  blood;  and  it  is  probable  that  a 
considerable  reduction  of  its  density  will  be  thus  produced  in  a  state  of  health, 
only  when  it  has  first  undergone  an  unusual  elevation,  in  consequence  of  the 
removal  of  part  of  its  water  by  perspiration,  diuresis,  &c.,  without  a  correspond- 
ing replacement  of  it  by  absorption.  It  has  been  affirmed,  however,  that  when 
Oxen  have  taken  immense  draughts  of  water,  the  blood  has  been  so  much  diluted, 
that  some  of  the  corpuscles  have  burst  (§  158)  and  their  colouring-matter  has 
passed  out  of  the  body;  whilst,  on  the  other  hand,  it  has  been  found  that  when 
two  Dogs  had  been  kept  for  some  weeks  on  the  same  kind  of  food,  but  one  was 
not  allowed  to  drink,  whilst  the  other  was  made  to  take  a  large  quantity  of  water, 

1  "Zeitschr.  fur  wissenchaft.  Zool.,"  1853,  cited  in  Prof.   Lehmann's  "  Physiologischw 
Chetnie,"  2nd  edit.,  band  ii.  p.  217. 

*  "  Characteristik  der  Cholera,"  \\  161-164. 


192  OF   THE   BLOOD; 

the  specific  gravity  of  the  blood  was  nearly  the  same  in  each.1 — The  influence  of 
the  Regimen  upon  the  composition  of  the  blood,  however,  appears  to  be  more 
definite  and  constant.  An  animal  diet  tends  to  increase  the  whole  amount  of 
solid  matter,  but  especially  to  augment  the  proportion  of  corpuscles.  On  the 
other  hand,  a  vegetable  diet  tends  to  lower  the  whole  amount  of  solid  matter,  occa- 
sioning a  marked  reduction  in  the  corpuscles,  whilst  it  seems  rather  to.  increase  the 
albumen ;  thus  showing  that  the  decrease  in  the  corpuscles  is  not  due  to  a  deficiency 
in  their  azotized  pabulum,  but  depends  on  some  other  condition.  The  develop- 
ment of  fibrin  appears  to  take  place  at  least  as  readily  on  the  vegetable,  as  on  the 
animal  regimen.  Hence  we  see  what  may,  and  what  may  not,  be  effected  in  the 
treatment  of  disease,  by  the  adoption  of  a  particular  dietetic  system ;  for  we  may 
promote  or  retard  the  development  of  the  red  corpuscles,  by  the  employment  of  an 
animal  or  a  vegetable  regimen,  but  can  make  little  or  no  impression  upon  the 
fibrin.2 — The  effect  of  complete  abstinence  from  food,  also,  or  of  a  continued  insuf- 
ficient supply  of  it,  is  to  reduce  the  proportion  of  the  whole  solid  constituents ; 
but  in  this  case,  too,  the  corpuscles  are  much  more  reduced  than  the  albumen ; 
and  very  little  effect  is  produced  upon  the  fibrin,  which  at  once  undergoes  an 
absolute  increase,  if  any  inflammatory  affection  should  develope  itself. 

178.  The  effect  of  Loss  of  Blood  is  of  a  very  similar  nature  to  that  of  absti- 
nence. Almost  as  soon  as  the  stream  begins  to  flow  from  a  wounded  vessel,  there 
seems  to  be  a  transudation  of  watery  fluid  from  the  tissues  into  the  current  of 
blood  j  for  this  undergoes  a  rapid  diminution  in  density,  so  that  the  portion  last 
drawn  is  of  lower  specific  gravity,  and  contains  a  considerably  smaller  amount  of 
solid  matter,  than  that  which  first  issued.  This  fact,  which  has  long  been  known, 
has  of  late  been  more  precisely  determined  by  Drs.  Zimmerman,3  Polli,4  and  J. 
Davy.5  When  blood  has  been  repeatedly  drawn,  or  has  been  lost  by  haemorrhage, 
that  which  remains  is  impoverished ;  but  the  reduction  in  its  whole  amount  of 
solid  matter  here  also  lies  rather  in  the  diminution  of  the  corpuscles,  than  in  that 
of  the  other  constituents.  This  is  shown  by  the  following  table  of  the  results  of 
MM.  Becquerel  and  Rodier's  analyses  of  the  blood  of  ten  patients,  each  of  whom 
had  been  bled  three  times  : 

1st  Venesection.    2d  Venesection.    3d  Venesection. 

Specific  gravity  of  defibrinated  blood 1056-0  1053-0  1049-6 

serum 1028-8  1026-3  1025-6 

Water 793-0  807-7  823-1 

Solid  residue 207-0  192-3  176-9 

Fibrin 3-5  3-8  3-4 

Corpuscles 129-2  116-3  99-4 

Albumen 65-0  63-7  64-6 

Extractive  and  saline  matters 7-7  6-9  8-0 

Fat 1-6  1-6  1-5 

Hence  it  is  obvious  that  the  special  effect  of  bleeding  is  to  lower  the  proportion 
of  Red  corpuscles,  and  that  it  has  no  power  of  effecting  a  diminution  in  the 
amount  of  fibrin.  We  shall  find,  indeed,  that  in  inflammatory  diseases  the 
amount  of  fibrin  undergoes  an  extraordinary  increase  (§  192),  which  is  not 
checked  in  the  slightest  appreciable  degree  by  the  most  copious  venesection.  It 
is  remarkable  that  after  very  considerable  losses  of  blood  a  decided  increase 
shows  itself  in  the  proportion  of  Colourless  corpuscles,  not  only  relatively  (as  to 
the  red)  but  absolutely  ;  so  that,  in  the  blood  of  a  Horse  from  which  50  Ibs.  have 
been  previously  abstracted,  the  coloured  and  the  colourless  corpuscles  appear  to 
exist  in  equal  numbers.6 

Dr.  Bence  Jones  in  "  Medical  Times,"  Aug.  2,  1851,  p.  115. 

See  on  this  subject  the  treatise  of  M.  Emile  Marchand,   "  De  Plnfluence  comparative 
du  Regime  Ve"ge"tal  et  du  Regime  Animal  sur  le  Physique  et  le  Moral  de  1'Homme." 
"  Heller's  Archiv.,"  band  iv.  p.  385. 
See  "  Medico-Chirurgical  Review,"  Oct.  1847. 
"  Anatomical  and  Physiological  Researches,"  vol.  ii.  p.  28. 
Kolliker's  "  Manual  of  Human  Histology"  (Sydenham  Society's  Edit.),  vol.  ii.  p.  330. 


ITS   PHYSICAL,    CHEMICAL,    AND    STRUCTURAL    CHARACTERS.         193 

179.  We  "have  now  to  consider  the  differences  which  present  themselves,  in  the 
composition  of  the  Blood  drawn  from  different  vessels  of  the  same  body;  these, 
it  is  obvious,  being  dependent  on  the  changes  to  which  the  fluid  is  subjected 
during  its  passage  through  organs  that  will  appropriate  or  change  its  several  con- 
stituents in  an  unequal  degree.  And  the  first  and  most  important  of  these  sets 
of  differences,  is  that  which  exists  between  Arterial  and  Venous  blood.  The 
analyses  already  cited  having  been  made  chiefly  upon  the  latter,  it  will  be  suf- 
ficient here  to  state  the  general  results  of  comparative  inquiries  into  the  composi- 
tion of  the  former.  The  quantity  of  solid  constituents  pertaining  to  the  Corpus- 
cles is  smaller;  they  contain  relatively  more  haematin  and  salts,  but  much  Jess 
fat.  The  liquor  sanguinis  is  somewhat  richer  in  Fibrin;  but  it  contains  a  larger 
proportion  of  water,  and  consequently  less  Albumen.  The  Fatty  matters  of  the 
serum,  as  well  as  of  the  corpuscles,  are  considerably  diminished  ;  on  the  other 
hand,  the  Extractive  matters  are  decidedly  increased.  It  is  affirmed  by  Dr.  G 
0.  Rees,1  that  the  phosphorus  which  exists  in  venous  blood  in  an  unoxidized  state, 
united  to  the  fat  of  the  corpuscles,  is  converted  by  the  respiratory  process  into 
phosphoric  acid,  which  passes  into  the  serum  and  unites  with  alkaline  bases;  and 
this  view  seems  borne  out  by  the  more  recent  analyses  of  Reich.2 — The  most 
remarkable  difference  between  Arterial  and  Venous  blood,  however,  lies  in  the 
amount  of  free  gases  which  they  respectively  contain.  It  may  now  be  considered 
as  unquestionably  proved  by  the  researches  of  Stevens,  Bischoff,  J.  Davy,  Magnus, 
and  others  (but  more  especially  by  those  of  the  last-named  experimenter),  that 
both  venous  and  arterial  blood  contain  Oyxgen,  Nitrogen,  and  Carbonic  acid  in  a 
state  of  solution ;  these  gases  being  yielded-up  by  the  blood  when  it  is  placed  in 
a  perfect  vacuum  ;3  and  carbonic  acid  being  also  disengaged,  when  the  fluid  is 
shaken  with  common  air,  or  with  oxygen,  hydrogen,  or  nitrogen  ;  while  oxygen 
is  in  like  manner  expelled  by  hydrogen  or  nitrogen,  which  takes  its  place.  The 
experiments  of  Magnus4  show  that  from  10  to  12 £  per  cent  of  Oxygen  (by 
volume)  exists  in  arterial  blood ;  but  that  this  is  reduced  in  venous  blood  to  half 
its  amount.  On  the  other  hand,  the  quantity  of  Carbonic  acid  which  is  thus 
removable,  amounts  to  about  25  per  cent  (by  volume)  in  venous  blood,  and  to 
only  20  in  arterial.  The  per-centage  of  Nitrogen  was  found  to  vary  from  1-7  to 
3-3;  but  no  constant  difference  presented  itself  between  the  quantities  contaihed 
in  arterial  and  in  venous  blood  respectively.  The  differences  in  the  relative  pro- 
portions of  Oxygen  and  Carbonic  acid  in  arterial  and  venous  blood  respectively, 
c mfirm  the  indications  afforded  by  other  facts  (CHAP.  Viz.),  that  an  exchange  of 
oxygen  for  carbonic  acid  takes  place  in  the  systemic  circulation,  and  an  exchange 
of  carbonic  acid  for  oxygen  in  the  general  circulation.  How  far  the  gases  thus 
introduced  into  the  blood  enter  into  chemical  combination  with  any  of  its  con- 
stituents, or  are  merely  dissolved  in  the  liquid,  has  not  been  positively  determined; 
there  is  reason  to  think,  however,  that  if  combination  thus  takes  place,  the  pro- 
portion so  employed  is  extremely  small.5  The  remarkable  power  of  absorbing 
carbonic  acid,  which  is  possessed  by  the  serum,  and  still  more  by  the  Red  cor- 
puscles, has  been  already  mentioned  (§  160);  and  there  would  be  no  difficulty  in 
accounting  for  the  presence  of  many  times  the  amount  of  that  gas  which  is 
actually  found  in  the  blood,  without  supposing  it  to  lose  its  freedom  by  combi- 
nation. 

180.  The  increase  of  the  Fibrin,  however,  which  seems  to  be  effected  during 

1  "  Philosophical  Magazine,"  vol.  xxxiii.  p.  28. 

2  "Arch,  der  Pharmacie,"  and  "  Leibig  and  Kopp's  Report,"  for  1849,  p.  366. 

8  It  has  been  found  by  Magnus,  that  carbonic  acid  is  not  given  off  under  the  receiver  of 
an  air-pump,  until  the  air  has  been  so  far  exhausted  that  it  only  supports  one  inch  of 
mercury.  This  fact  explains  the  negative  result  obtained  by  many  experimenters ;  since 
an  extremely  good  air-pump  is  required  to  produce  such  a  degree  of  exhaustion. 

*  See  "  Ann.  der  Physik  and  Chemie."  band  Ixvi.  p.  177  ;  and  an  abstract  in  the  "Philo- 
sophical Magazine,"  Dec.  1845. 

»  See  Lehmann,  Op.  cit.  vol.  ii.  p.  192. 
13 


194  OF   THE   BLOOD; 

the  aeration  of  the  Blood,  must  be  taken  as  an  indication  that  a  certain  part  of 
the  oxygen  absorbed  from  the  air  is  made  directly  subservient  to  changes  in  the 
composition  of  the  circulating  fluid;  and  it  appears  from  certain  of  its  reactions, 
that  the  fibrin  of  arterial  blood  must  be  in  a  state  of  higher  oxidation  than  that 
of  venous.  Now  although  the  differences  between  fibrin  and  albumen  lead  us  to 
regard  the  production  of  the  former  from  the  latter  as  rather  a  vital  than  a 
chemical  change,  yet  the  existence  of  the  difference  in  question  obviously  points 
to  the  presence  of  oxygen  as  a  condition  essential  to  its  performance ;  and  this 
inference  is  fully  confirmed  by  the  experiments  of  Dr.  Gairdner,1  on  the  influence 
of  the  respiration  of  pure  oxygen  on  the  production  of  fibrin.  As  the  Rabbit 
was  on  many  accounts  the  most  convenient  warm-blooded  animal  for  such  a  trial, 
he  first  set  himself  to  determine  the  normal  proportions  of  the  constituents  of  its 
blood.  The  analysis  of  the  blood  drawn  from  the  aorta  in  six  healthy  indi- 
viduals, yielded  the  following  results  : — 

Mean.  Max.  Min. 

Fibrin 1-65  200  1-45 

Corpuscles 82-35  92-00  70-00 

Albumen 46-30  68-00  37-20 

On  the  other  hand,  the  analysis  of  the  blood  of  three  individuals  which  had 
been  made  to  respire  pure  oxygen  for  half  an  hour,  gave  the  following  as  the 
proportions  of  its  components  : — 

Mean.  Max.  Min. 

Fibrin 2-40  2-50  2-30 

Corpuscles 69-56  75-00  60-50 

Albumen 40-23  45-70  35-00 

It  is  further  stated  by  Dr.  G-airdner  (Op.  cit.,  p.  183),  that  a  rabbit  having  been 
kept  for  half  an  hour  under  the  influence  of  an  electro-magnetic  current  between 
the  chest  and  spine,  which  produced  a  great  acceleration  in  the  respiratory  move- 
ments, its  blood  was  found  to  contain  as  much  as  2-9  parts  of  fibrin  in  1?)00.  — 
The  larger  quantity  of  fibrin  in  arterial  blood  of  itself  renders  its  coagulum 
firmer ;  but  independently  of  this,  there  would  seem  to  be  a  difference  in  the 
quality  of  the  fibrin,  which,  when  separated  by  stirring  or  whipping,  is  more 
tenacious  and  compact  in  arterial  than  in  venous  blood. 

181.  The  proportion  of  Red  Corpuscles  in  arterial  and  venous  blood  respec- 
tively, has  been  variously  stated  by  different  observers ;  and  we  may  easily  con- 
ceive it  to  be  affected  by  several  circumstances,  which  may  produce  a  change  in 
the  whole  proportion  of  the  solid  to  the  fluid  constituents  of  the  blood,  during 
the  course  of  its  circulation.  Thus,  the  discharge  of  the  contents  of  the  thoracic 
duct  into  the  venous  system  near  the  heart,  will  tend  to  dilute  the  blood  of  the 
pulmonary  and  arterial  circulation ;  whilst,  conversely,  the  escape  of  the  watery 
part  of  the  blood  by  the  renal  and  cutaneous  secretions,  and  by  transudation  into 
the  tissues,  which  takes  place  during  its  passage  through  the  systemic  capillaries, 
will  tend  to  augment  the  proportion  of  the  solids  of  the  blood  drawn  from  the 
systemic  veins.  On  the  other  hand,  if  the  discharge  of  fluid  from  the  thoracic 
duct  be  suspended,  and  the  amount  absorbed  from  the  tissues  during  the  systemic 
circulation  should  exceed  that  which  is  transuded  (as  appeals  sometimes  to  happen, 
§  178),  then  the  proportion  of  solid  matter  will  be  less  in  venous  than  in  arterial 
blood. — No  such  explanation  will  apply,  however,  to  the  very  marked  differences 
exhibited  in  Dr.  Gairdner's  experiments  just  cited,  between  the  proportions  of 
red  corpuscles  and  of  albumen  in  the  ordinary  arterial  blood  of  rabbits,  and  in 
that  of  the  individuals  whose  blood  had  been  hyper-arterialized ;  the  sum  of  the 
averages  in  the  former  case  being  128-65,  and  in  the  latter  109-79,  the  difference 

1  Treatise  "On  Gout,"  2nd  edit.,  pp.  153-4. 


ITS    PHYSICAL,  CHEMICAL,  AND   STRUCTURAL   CHARACTERS.,         195 

of  wliich  is  18-86,  or  nearly  one-seventh  of  the  larger  amount.  Still,  that  this 
difference  is  in  great  part  due,  rather  to  dilution  of  the  blood,  than  to  the  abso- 
lute diminution  in  its  entire  amount  of  red  corpuscles  and  of  albumen,  would 
seem  probable  from  the  fact  that  their  relative  amount  is  almost  exactly  the  same 
in  the  two  cases,  the  proportion  of  corpuscles  to  albumen  being  1-78  :1  in  the 
normal  blood,  and  1'72  : 1  in  the  oxygenated.1 

182.  The  difference  in  the  colour  of  arterial  and  of  venous  blood,  which  is 
entirely  dependent  upon  the  state  of  the  Red  Corpuscles,  has  been  commonly 
supposed  to  be  produced  by  a  chemical  change  exerted  upon  their  Hsematin  by 
oxygen  and  carbonic  acid  respectively.  Of  such  change,  however,  there  is  no 
adequate  evidence ;  and  there  are  many  indications  that  we  are  to  look  for  the 
source  of  the  difference  of  colour,  rather  in  modifications  in  the  form  of  the  cor- 
puscles, affecting  their  power  of  transmitting  and  reflecting  light,  than  in  any 
chemical  alterations  of  their  contents.  It  is  true  that  if  arterial  blood  be  exposed 
to  carbonic  acid  out  of  the  body,  it  will  acquire  the  dark  hue  of  venous  blood ; 
whilst,  conversely,  venous  blood  exposed  to  oxygen  will  acquire  (on  its  surface  at 
least)  the  florid  hue  of  arterial  blood.  But  for  these  changes  to  take  place,  it  is 
necessary  that  the  normal  proportion  of  saline  matter  should  exist  in  the  serum 
in  which  the  corpuscles  float,  and  that  the  corpuscles  themselves  should  not  have 
ruptured  and  discharged  their  haematin.  For  if  arterial  blood  deprived  of  its 
fibrin  be  diluted  with  twice  or  thrice  its  volume  of  water,  it  assumes  a  dark 
venous  tint,  which  is  not  affected  by  the  passage  of  a  current  of  oxygen  through 
it  •  yet  the  red  colour  is  restored  by  the  addition  of  a  saturated  solution  of  a 
neutral  salt,  even  without  the  contact  of  oxygen.  On  the  other  hand,  venous 
blood  is  reddened  by  the  addition  of  a  strong  saline  solution,  without  any  exposure 
to  oxygen  j  and  it  is  not  readily  darkened  again  by  the  passage  of  carbonic  acid 
through  it.  Again,  a  scarlet  clot  is  darkened  by  washing  it  with  distilled  water, 
and  it  is  only  very  slowly  reddened  by  exposure  to  oxygen;  whilst  a  black  clot 
becomes  at  once  scarlet  when  it  is  washed  with  salt,  and  is  not  blackened  again 
by  carbonic  acid.  Further,  if  the  corpuscles  be  treated  with  water  until  they 
burst,  so  that  the  hsematin  is  diffused  through  the  liquid,  scarcely  any  effect  is 
produced  upon  the  hue  of  the  solution,  either  by  carbonic  acid,  by  oxygen,  or  by 
salines ;  such  slight  alteration  as  does  occur  being  fairly  attributable,  either  to 
the  presence  of  a  few  corpuscles  still  unruptured,  or  to  the  influence  which  the 
absorption  of  these  gases  may  produce  upon  the  colouring  matter,  without  enter- 
ing into  chemical  combination  with  it.2  Hence  it  is  obvious  that  the  light  or 
dark  colour  of  the  blood  affords  no  indication  whatever  of  its  state  of  oxygenation, 
since  the  change  from  the  one  to  the  other  may  be  effected  by  other  agents  ;  and 
if  we  examine  into  the  nature  of  their  influence,  we  find  that  the  blood  is  dark- 
ened by  whatever  tends  to  distend  the  corpuscles,  so  as  to  render  them  flat  or  bi- 
convex, whilst  it  is  brightened  by  whatever  tends  to  empty  them,  so  as  to  render 
them  more  deeply  bi-concave  than  usual.  And  observation  of  the  effects  of 
oxygen  and  carbonic  acid,  respectively,  upon  the  form  of  the  corpuscles,  confirms  the 
idea  that  this  is  the  mode  in  which  these  agents  affect  their  colour;  for  the  former 
causes  their  contraction,  and  renders  their  cell-walls  thick  and  granular,  so  as  to 
increase  their  power  of  reflecting  light;  whilst  the  latter,  producing  a  dilatation 
of  the  corpuscles,  thins  their  cell-walls,  and  enables  them  to  transmit  light  more 
readily.  That  an  increase  in  the  opacity  and  reflecting  power  of  the  corpuscles 
tends  to  heighten  the  colour  of  the  blood,  is  shown  by  an  experiment  of  Scherer's; 
who  found  that  when  defibrinated  blood  had  been  darkened  by  the  addition  of 

1  It  would  be  important  to  determine  the  comparative  amount  of  carbonic  acid,  and  of 
the  solids  of  the  urine,  excreted  in  the  same  time  by  two  sets  of  animals  placed  under 
these  very  diverse  conditions. 

3  It  has  been  shown  by  Peligot,  that  the  colours  of  solutions  of  the  salts  of  the  protoxide 
of  iron  are  considerably  modified  by  passing  a  current  of  protoxide  of  nitrogen  through 
them,  although  no  chemical  change  is  thereby  induced. 


106  OF  THE   BLOOD; 

water,  its  original  bright  colour  was  restored  by  the  addition  of  a  little  milk,  oil, 
or  finely-powdered  chalk  or  gypsum.1 

183.  Although  no  difference  can  be  detected  between  samples  of  blood  drawn 
from  various  parts  of  the  Arterial  system  of  the  same  animal,  very  important 
variations  exist,  as  might  be  expected,  in  the  composition  of  the  blood  drawn  from 
the  several  parts  of  the  Venous  system  ;  since  the  changes  to  which  it  has  been 
subjected  in  the  several  organs  through  which  it  has  passed,  are  of  a  very  diver- 
sified character.  The  blood  of  the  Vena  Port93,  for  example,  differs  considerably 
from  the  blood  of  the  Hepatic  vein,  and  both  of  these  differ  from  the  blood  of  the 
Jugular.  So,  again,  the  blood  of  the  Splenic  vein  differs  from  all  the  preceding ; 
and  so  must  the  blood  of  the  Renal  vein,  although  this  latter  difference  has  not  yet 
been  demonstrated  by  direct  analysis.  The  iiost  important  and  best-established  of 
these,  diversities  will  now  be  enumerated. —  Ln  speaking  of  the  composition  of  the 
blood  of  the  Vena  Portse,  it  must  be  remembered  that  this  consists  of  two  very  dis- 
tinct factors,  namely,  the  blood  of  the  Gastric  and  Mesenteric  veins,  and  the  blood 
of  the  Splenic  vein  ;  the  former  having  been  altered  by  the  introduction  of  solid 
and  liquid  alimentary  matters,  and  the  latter  by  its  circulation  through  the  Spleen. 
These,  therefore,  ought  to  be  separately  studied ;  and  this  has  been  done  by  M. 
Jules  Beclard.2  The  characters  of  the  blood  returning  by  the  Gastric  and  Mesen- 
teric veins  from  the  walls  of  the  alimentary  canal,  are  of  course  affected  by  the  stage 
of  the  digestive  process,  and  by  the  nature  and  amount  of  the  absorbable  matters. 
As  compared  with  the  ordinary  venous  blood  the  total  quantity  of  its  solid  consti- 
tuents is  lowered  during  the  early  part  of  the  digestive  process,  by  the  dilution  it 
suffers  through  the  imbibition  of  liquid ;  and  this  diminution  is  especially  remark- 
able in  the  corpuscles,  the  relative  proportion  of  albumen  being  increased  by  the 
introduction  of  new  albuminous  matter  from  the  food.  Towards  the  conclusion  of 
the  digestive  process,  however,  the  blood  of  the  mesenteric  veins  gradually  comes 
to  present  the  ordinary  proportions  of  these  two  components;  and  in  an  animal 
that  has  been  subjected  to  long  abstinence,  it  does  not  differ  from  that  of  the 
venous  system  in  general.  The  quantity  of  extractive  is  usually  increased ;  and  in 
this  part  of  the  blood  it  must  be,  that  sugar,  dextrin,  gelatin,  and  other  soluble  or- 
ganic matters  that  are  taken  into  the  circulation,  are  contained.  Some  of  these  have 
in  fact  been  detected  in  it.3  The  fibrin  of  the  blood  of  the  mesenteric  veins  appears 
to  be  less  perfectly  elaborated  than  that  of  the  blood  in  general;  for  the  blood  of  the 
mesenteric  veins  coagulates  less  firmly  (having  been  erroneously  asserted  by  some 
not  to  coagulate  at  all);  and  its  fibrin,  when  separated  by  stirring,  shows  a 
marked  deficiency  in  tenacity,  and  liquefies  completely  in  the  course  of  a  few 
hours.  A  part  of  the  albuminous  constituent  of  this  blood  does  not  present  the 
characters  of  true  albumen,  for  it  is  not  precipitated  by  heat  or  by  nitric  acid,  and 
the  precipitate  thrown-down  by  alcohol  is  redissolved  by  water;  like  albumen, 
however,  it  is  precipitated  by  the  metallic  salts,  creasote,  and  tannin.  This  sub- 
stance, which  has  been  distinguished  by  M.  Mialhe  as  albuminose,  further  differs 
from  true  albumen  in  the  facility  with  which  it  traverses  organic  membranes ; 
for  these  resist  the  passage  of  albumen,  while  they  are  freely  transuded  by 
albuminose.  And  it  is  affirmed  by  M.  Mialhe,  that  the  want  of  that  conversion 

1  See,  on  this  subject,  the  reports  by  Scherer  in  "  Canstatt's  Jahresbericht"  for  1844  and 
subsequent  years,  and  the  works  therein  referred  to ;  also  Mulder's  "  Chemistry  of  Animal 
and  Vegetable  Physiology,"  (translated  by  Prof.  Johnston),  pp.  338 — 344. — It  has  been 
lately  found  by  Bruch,  that  blood  impregnated  with  oxygen  becomes  darker  under  the  air- 
pump  ;  while  blood  saturated  with  carbonic  acid  and  placed  in  vacuo  did  not  become  lighter, 
but  retained  its  characteristic  dark  tint  (whether  treated  with  water  or  not,  notwithstand- 
ing the  loss  of  a  large  quantity  of  carbonic  acid.     (See  "  Zeitsch.  fiir  Wissen.  Zoll.,"  band 
iv.  p.  273.) 

2  See  his  Memoir  in  the  Arch.  Ge"n.  de  Me"d.,"  4e  se"rie,  torn,  xviii.  p.  322,  etseq. ;  and  his 
edition  of  his  father's  "Elemens  d' Anatomic  Generate,"  pp.  265,.266. 

3  See  the  Researches  of  MM.  Bourchardat  and  Sandras,  in  the  "  Supplement  a  1'Annu- 
aire  de  Thernpeutique,"  1846. 


ITS    PHYSICAL,    CHEMICAL,    AND    STRUCTURAL   CHARACTERS.         197 

of  albuminose  into  albumen,  which  ought  to  take  place  as  part  of  the  assimilating 
process,  is  one  cause  of  the  readiness  with  which  albuminous  matter  transudes 
from  the  blood  in  albuminuria  and  in  dropsies;  this  albuminous  matter  frequently 
having  rather  the  characters  of  albuminose,  than  those  of  true  albumen.1 

184.  On  the  other  hand,  the  blood  of  the  Splenic  vein  is  stated  by  M. 
Beclard  to  exhibit  a  notable  diminution  in  the  proportion  of  red  corpuscles, 
whilst  its  albumen  is  greatly  augmented,  the  total  amount  of  its  solid  matter 
differing  but  little  from  that  of  arterial  blood;  as  is  shown  by  the  following  com- 
parative  statement  of  the  proportions  of  the  water  and  the  solids  of  the  blood  of 
the  same  animal,  in  different  parts  of  its  circulation. 

External  Mammary  Splenic 

Jugular  Vein.  Artery.  Vein. 

Water '778-9  750-6  746-3 

Albumen 79-4  85-9  124-4 

Corpuscles  and  Fibrin 141-7  159-9  128-9 

The  proportion  of  fibrin  seems  to  be  larger  in  the  blood  of  the  splenic  vein,  than 
in  that  of  the  venous  system  in  general ;  but,  like  that  of  the  mesenteric  vein, 
the  separated  fibrin  is  deficient  in  tenacity,  and  early  passes  into  the  state  of 
liquefaction.2 — That  the  Spleen  ordinarily  effects  a  marked  change  in  the  consti- 
tution of  the  blood  which  passes  through  it,  appears  also  from  the  analyses  made 
by  Mr.  Gray,3  of  the  blood  drawn  from  the  interior  of  the  organ  itself  after  its 
removal,  the  splenic  vein  having  been  previously  tied.  The  nature  and  amount 
of  these  changes,  however,  differ  in  a  very  marked  degree,  according  to  the  stage 
of  the  digestive  operation  and  the  general  condition  of  the  nutritive  functions ; 
and  it  is  to  this  circumstance,  that  we  are  probably  to  ascribe  much  of  the  diver- 
sity in  the  results  obtained  by  previous  experimenters.  A  marked  decrease  in 
the  total  amount  of  solid  matter  is  generally  observable ;  the  average  of  twelve 
experimenters  giving  only  187 •!  per  1000  of  solid  constituents  in  the  splenic 
blood,  whilst  the  arterial  blood  of  the  same  animals  contained  239  parts,  and  the 
jugular  venous  blood  201  parts.  This  decrease  depends  upon  the  diminished 
proportion  of  red  corpuscles,  which  seems  always  to  present  itself,  except  in 
starved  or  extremely  ill-fed  animals;  the  amount  of  this 
reduction,  however,  varies  extremely,  having  been,  in  one  of  Fia  62. 

the  horses  experimented  on  by  Mr.  Gray  (Op.  cit.,  p.  157), 


somewhat  less  than  one-fourth,  in    another  about    one-third,  ftjj   /ji      I  i 

in  another  about  one-half,  in  another  as  much  as  two-thirds,  ,\   aW       */ 

and  in  another  no  less  than  five-sevenths.     On  the  other  hand, 

the  albumen  usually  exhibits  a  marked  increase,  which  may 

even  double  its  previous  amount ;  and  this  seems  greatest  at  Blood- corpuscles 

an  interval  of  some  hours  after  feeding.     Tfeejtffirw  seems  to  with  rod-like  yellow 

be  almost  constantly  augmented,  and  this  sometimes  in  a  very  crystals,  from  Sple. 

remarkable  degree;  the  quantity  found  in  the  splenic  blood     nic,1Ve!,n  °*pe.rc\s 
rtcj.ii  eo  •      -IAAA         f  a,  blood-cells,  treat- 

varying  from  2-0  to  11 -53  parts  in  1000,  or  from  an  amount     e^  with  water;  b, 

a  little   above  the  usual  standard,  to  nearly  six  times  that     free  crystals, 
average.  —  It  does  not  appear,  however,  that  the  increase  of 
fibrin  and  albumen  stand  in  any  such  relation  of  uniformity  to  the  diminution 
of  the  red  corpuscles,  that  the  augmentation  of  the  former  may  be  directly  at- 
tributed to  the  disintegration  of  the  latter,  so  that  these  changes  would  rather 

1  See  the  "Cours  de  Physiologie"  of  M.  Paul  Be'rard,  torn.  iii.  p.  87. 

2  The  serum  of  the  blood  of  the  splenic  vein  of  the  horse,  was  found  by  M.  Be'clard  lu 
two  instances  to  undergo  spontaneous  coagulation,  five  and  eight  hours  after  its  removal 
from  the  crassamentum,  in  contact  with  which  it  had  been  left  for  the  preceding  twenty- 
four  hours.     This  spontaneous  coagulation  induces  the  existence  of  a  compound  of  a 
fibrinous  nature,  which,  however,  could  not  have  been  fully  elaborated,  since  it  did  not 
coagulate  with  the  true  fibrin,  and  which  differed  from  albumen  in  the  spontaneity  of  its 
change  of  state;  and  we  may  consider  the  substance,  with  much  probability,  to  have  been 
in  a  transition-state  between  the  two. 

3  "On  the  Structure  and  Uses  of  the  Spleen,"  1854. 


198  OF  THE  BLOOD; 

seem  to  be  concurrent,  than  to  be  mutually  dependent.1  The  blood  of  the 
Splenic  vein  is  further  remarkable  for  the  large  proportion  of  colourless  corpus- 
cles (apparently  derived  from  the  white  portion  of  its  parenchyma)  which  it  in- 
cludes; and  also  for  containing  a  number  of  peculiar  cells  including  rod-like 
crystals  of  reddish-yellow  colouring  matter  (Fig.  62),  which  seem  to  be  red  cor- 
puscles in  a  state  of  degeneration  (§  142,  in). 

185.  Many  comparative  observations  have  been  made  upon  the  blood  of  the 
Vena  Portse  and  of  the  Hepatic  vein;  but  a  large  part  of  them,  according  to 
M.  01.  Bernard,  are  vitiated  by  the  fact,  that,  unless  the  vena  portae  be  tied,  a 
reflux  of  blood  takes  place  into  it  from  the  liver,  so  that  the  blood  which  flows 
when  it  is  wounded,  is  not  so  much  portal  as  hepatic  blood.  According  to  thig 
experimenter,  the  blood  of  the  hepatic  vein  is  peculiar  as  containing  an  increased 
proportion  not  only  of  sugar  but  also  of  fat;  these  substances  being  generated, 
during  the  passage  of  the  blood  through  the  liver,  not  only  from  amylaceous  or 
other  saccharine  matters,  but  even  from  azotized  compounds.  The  production 
of  fat  is  to  a  certain  degree  vicarious  with  that  of  sugar ;  and  the  former  is  cha- 
racteristic of  herbivorous,  the  latter  of  carnivorous  animals.  He  also  maintains 
that  there  is  a  decided  augmentation  in  the  quantity  of  fibrin  which  it  contains  :2 
but  although  he  is  probably  mistaken  on  this  point,  he  has  clearly  shown  that 
the  albuminous  constituent  undergoes  some  change  in  passing  through  the  liver, 
by  which  it  is  rendered  more  fit  to  enter  the  general  circulation.3 — According  to 
Prof.  Lehmann,  the  blood  of  the  hepatic  vein  differs  from  that  of  the  portal  in 
the  following  particulars.  "It  is  far  poorer  in  water;  so  that,  assuming  the 
solid  constituents  of  the  blood  to  be  equal  in  both  kinds  of  blood,  the  quantity 
of  water  in  the  blood  of  the  portal  vein  is  to  that  in  the  blood  of  the  hepatic 
vein  as  4  :  3,  during  digestion  and  when  not  much  drink  has  been  taken,  and 
sometimes  as  much  as  12  :  5,  after  digestion  has  been  fully  accomplished.  The 
clot  of  the  blood  of  the  hepatic  vein  is  bulky  and  readily  breaks-down.  Whilst 
34  parts  of  serum  are  separated  from  100  parts  of  portal  blood,  only  15  are  se- 
parated from  100  parts  of  the  blood  of  the  hepatic  vein.  The  blood  of  the 
hepatic  vein  is  far  richer  in  blood-cells,  both  coloured  and  colourless,  than  that 
of  the  portal  vein ;  the  colourless  corpuscles  occur  in  the  roost  varied  shapes  and 
sizes;  the  coloured  are  seen  in  heaps  of  a  distinct  violet  colour,  and  their  cell- 
walls  are  less  readily  destroyed  by  water  than '  are  those  of  the  blood  of  most 
other  vessels.  While  in  the  blood  of  the  portal  vein  there  are  141  parts  of  moist 
blood-cells  to  100  parts  of  plasma,  in  the  blood  of  the  hepatic  vein  there  are  317 
parts  of  moist  blood-cells  to  100  of  plasma.  The  cells  in  the  blood  of  the 
hepatic  veins  are  poorer  in  fat  and  in  salts,  and  especially  in  hsematin,  or  at 
least  iron,  but  somewhat  richer  in  extractive  matters.  Their  specific  gravity  is 
higher  than  that  of  the  cells  of  the  portal  blood,  notwithstanding  the  diminished 
quantity  of  iron.  The  plasma  of  the  blood  of  the  hepatic  veins  is  far  denser 
than  that  of  the  blood  of  the  portal  vein,  for  it  contains  a  much  larger  amount 
of  solid  constituents  generally,  although  little  or  no  fibrin  is  to  be  found  in  it  (?). 
While  there  are  8*4  parts  of  solid  matter  to  100  of  water  in  the  serum  of  portal 
blood,  there  are  11-8  parts  of  solid  matter  to  an  equal  quantity  of  water  in  the 
serum  of  the  blood  of  the  hepatic  vein.  If  we  compare  the  solid  constituents 
of  the  serum  of  both  kinds  of  blood,  we  find  less  albumen  and  fat,  and  far  less 

1  It  seems  obvious  that  such  an  erroneous  diminution  of  the  Red  Corpuscles  can  only 
take  place  in  blood  which  is  partially  or  completely  stagnated  in  the  organ ;  since,  if  the 
circulation  through  it  were  taking-place  at  the  usual  rate,  all  the  blood  in  the  body  would 
be  speedily  subjected  to  the  process,  and  its  corpuscles  would  be  (as  it  were)  entirely 
melted  down. — For  a  statement  of  Mr.  Gray's  views,  with  critical  observations  thereon, 
see  the  "Brit,  and  For.  Med.-Chir.  Rev.,"  Jan.,  1855. 

a  "  L'Union  Me*dicale,"  1849,  1850. — M.  Bernard  does  not  give  any  details  on  this  last 
point ;  and  he  does  not  seem  to  have  made  allowance  for  the  admixture  of  the  blood  of 
the  hepatic  artery  with  that  of  the  portal  vein. 

3  "  Gazette  Medicale,"  1850. 


ITS     CHARACTERS    IN    DISEASE.  199 

salts,  in  the  blood  of  the  hepatic  vein,  while  the  quantity  of  extractive  matter, 
including  sugar,  is  perceptibly  augmented/' '  —  It  cannot  be  doubted  that  when 
the  secretion  of  urine  is  proceeding  with  rapidity,  the  blood  of  the  Renal  vein 
must  contain  a  smaller  proportion  of  water  than  that  of  the  renal  artery,  and 
that  the  quantity  of  salines  also  must  be  diminished ;  since  a  separation  of  these 
ingredients  takes  place  in  the  passage  of  the  blood  through  the  renal  capillaries. 
So  far  as  regards  the  quantity  of  water,  this  a  priori  conclusion  has  been  con- 
firmed by  the  analyses  of  Simon,  who  found  790  parts  of  water  in  1000  of  blood 
drawn  from  the  renal  artery,  and  only  778  in  blood  drawn  from  the  renal  vein  of 
the  same  animal.2  The  proportion  of  salts,  however,  has  not  been  analytically 
determined  to  be  different. 

186.  Alterations  in  the  Composition  of  the  Blood  in  Disease.  —  Und.^r  this 
head  it  is  intended  here  to  consider,  not  the  state  of  the  Blood  in  every  princi- 
pal type  of  disease  (which  it  is  the  duty  of  the  Pathologist  to  investigate),  but 
the  most  important  facts  which  the  study  of  its  morbid  conditions  has  afforded, 
towards  the  determination  of  the  conditions  under  which  decided  variations  take 
place  in  the  quantity  or  quality  of  its  principal  components,  and  of  the  effects 
which  those  variations  produce  upon  the  system   at  large.     The  first  series  of 
such  connected  researches,  as  afford  the  requisite  materials  for  this  inquiry,  was 
that  of  MM.  Andral  and  Gavarret,3  which  is  still  of  standard  value;  this  was 
followed  by  the  investigations  of  MM.  Becquerel  and  Rodier;4  and  many  addi- 
tional analyses  have  been  made  by  Popp,  Simon,  and  other  observers.     For  the 
purpose  of  comparison,  however,  as  already  remarked,  it  is  desirable  to  employ 
those  results  only,  which  have  been  obtained  by  processes  essentially  the  same ; 
and  hence  the  following  summary  will  be  chiefly  based  on  the  statements  of  the 
French  experimenters  whose  researches  have  been  just  referred-to. — It  is  neces- 
sary, however,  in  the  first  place,  to  assume  some  standard  of  composition,  which 
may  be  regarded  as  sufficiently  characteristic  of  health,  to  lead  us  to  rank  any 
variation  which  passes  beyond  its  limits  as  essentially  morbid;  and  this  standard 
must  be  fixed  according  to  the  method  of  analysis  employed.     Thus,  although  it 
has  been  shown   (§  170,  note}  that  the  calculation  of  the  proportionals  of  the 
principal  constituents  of  the  blood,  from  the  results  obtained  according  to  the 
method  of  MM.  Andral  and  Gavarret,  must  be  held  to  be  in  itself  erroneous, 
yet  as  the  same  method  was  followed  in  all  the  analyses  of  morbid  blood  made 
by  them  and  their  successors,  the  requisite  standard  must  be  erected  upon  this 
foundation ;  and  the  following  may  thus  be  considered  as  the  normal  range  of 
variation  for  the  principal  constituents  of  the  blood  in  health,  according  to  the 
foregoing  mode  of  estimating  them  : — 

Fibrin from  2  to         3J  parts  per  1000. 

Red  corpuscles "  110  "  152  "     '          " 

Solids  of  Serum "  72  ««       88  "  " 

Water "  760  "  815  "              " 

187.  The  first  of  these  components  whose   variations  we  shall  consider  is 
Fibrin;  the  estimate  of  which,  however,  is  open  to  an  important  fallacy,  that 
has  not  been  sufficiently  guarded-against, — namely,  the  admixture  of  the  Colour- 
less corpuscles.     "These/7  as  Mr.  Paget  correctly  remarks,  "cannot,  by  any 
mode  of  analysis  yet  invented,  be  separated  from  the  fibrin  of  mammalian  blood; 
their  composition  is  unknown,  but  their  weight  is  always  included  in  the  estimate 
of  the  fibrin.     In  health,  they  may,  perhaps,  add  too  little  to  its  weight  to  merit 
consideration ;  but  in  many  diseases,  especially  in  inflammatory  and  other  blood- 
diseases  in  which  the  fibrin  is  said  to  be  increased,  these  corpuscles  become  so 

1  "Physiological  Chemistry"  (Cavendish  Society's  Ed.),  vol.  ii.  p.  259. 
a  "  Simon's  Animal  Chemistry"  (Sydenham  Society's  Ed.),  vol.  i.  p.  214. 
3  "Essai  d'Hsematologie  Pathologique." 

*  "  Recherches  sur  la  Composition  du  Sang  dans  1'Etat  de  Sant6  et  dans  1'Etat  de 
Maladie." 


200  OF  THE   BLOOD; 

numerous  that  a  large  proportion  of  the  supposed  increase  of  the  fibrin  must  be 
due  to  their  being  weighed  with  it.  On  this  account,  all  the  statements  re- 
specting the  increase  of  fibrin  in  certain  diseases  need  revision."  l  Some  idea 
may  probably  be  formed  of  the  relative  proportion  of  fibrin  and  colourless  cor- 
puscles, in  the  colourless  coagulum  obtained  by  stirring  the  blood  or  by  washing 
the  ordinary  clot,  or  in  that  which  forms  the  '  buify  coat'  (§  205),  by  attending 
to  its  texture;  for  where  this  is  unusually  firm  and  almost  leathery,  as  it  com- 
monly is  in  the  blood  of  a  person  suffering  under  a  'sthenic'  inflammation,  either 
the  proportion  of  fibrin  must  be  augmented,  or  its  plasticity  must  be  increased, 
or  both  conditions  must  coexist ;  whilst,  on  the  other  hand,  when  the  colourless 
clot,  though  bulky,  is  deficient  in  tenacity  and  is  easily  broken  down  between 
the  fingers,  as  happens  with  that  of  blood  drawn  from  tubercular  subjects  when 
no  inflammation  is  present,  the  increase  is  probably  due  rather  to  an  augmenta- 
tion in  the  colourless  corpuscles,  than  to  that  of  the  fibrin.  —  In  the  results  of 
the  analyses  now  to  be  stated,  it  must  be  borne  in  mind  that  the  term  ' fibrin' 
really  designates  the  'colourless  coagulurn '  of  spontaneous  formation,  whatever 
may  be  its  composition. 

188.  The  most  important  fact  substantiated  by  Andral,  is  one  that  had  been 
previously  suspected, —  the  invariable  increase  in  the  quantity  of  Fibrin  during 
acute  Inflammatory  affections;  the  increase  being  strictly  proportional  to  the 
intensity  of  the  inflammation,  and  to  the  degree  of  symptomatic  fever  accom- 
panying it.  "  The  augmentation  of  the  quantity  of  Fibrin  is  so  certain  a  sign 
of  Inflammation,  that,  if  we  find  more  than  5  parts  of  fibrin  in  1000,  in  the 
course  of  any  disease,  we  may  positively  affirm  that  some  local  inflammation 
exists."  Several  cases  are  mentioned,  in  which  an  increase  to  7  or  7 £  parts  took 
place  without  any  apparent  cause ;  but  in  which  it  afterwards  proved  that  severe 
local  inflammation  had  been  present;  and  thus  we  are  furnished  with  a  pathogno- 
mic  sign  of  great  importance.  The  average  proportion  of  Fibrin  in  Inflammation 
maybe  estimated  at  7;  the  minimum  at  5;  the  maximum  at  13-3.  The  greatest 
augmentation  is  seen  in  Pneumonia  and  Acute  Rheumatism.  It  does  not  appear 
that  in  robust  athletic  persons,  the  proportion  of  Fibrin  is  greater  than  in  those 
of  feeble  constitution;  in  the  latter  it  is  the  corpuscles  that  are  deficient;  and 
it  is  rather  from  this  disproportion,  than  from  an  absolute  excess  of  Fibrin,  that 
their  greater  liability  to  Inflammatory  affections  arises.  Diseases  which  com- 
mence at  the  same  time  as  the  Inflammation,  or  which  co-exist  with  it,  do  not 
prevent  the  characteristic  increase  of  Fibrin ;  thus  in  Chlorotic  females,  the  pro- 
portion rises  to  6  or  7,  under  this  influence.  The  augmentation  is  observed  at 
the  very  outset  of  the  affection ;  the  quantity  increases  with  its  progress  ;  and 
a  decrease  shows  itself  when  the  disease  begins  to  abate.2  When  the  disease 
presents  alternations  of  increase  and  decline,  these  are  marked  by  precisely-cor- 
responding changes  in  the  quantity  of  Fibrin.  An  augmentation  is  commonly 
observable  during  the  advanced  stage  of  Phthisis,  in  spite  of  the  deterioration 
which  the  blood  must  then  have  undergone ;  this  is  probably  dependent  upon 
the  development  of  local  inflammation  around  the  tubercular  deposits.  In  one 
of  Popp's  observations,  the  proportion  of  fibrin  in  the  blood  of  a  phthisical 
patient  was  not  less  than  107. — Some  experiments  performed  by  M.  Andral  on 

1  Kirkes  and  Paget's  "Manual  of  Physiology,"  2d  Am.  Ed.,  p.  56. 

a  By  experiments  on  animals,  M.  Andral  has  ascertained  that  no  circumstance  of  pre- 
vious debility  or  privation  prevents  this  characteristic  change.  Having  ascertained  the  - 
amount  of  fibrin  in  the  blood  of  three  dogs  to  be  2-3,  2-2,  and  1-6  (the  natural  range  for 
these  animals),  he  deprived  them,  completely  or  partially,  of  food.  On  the  fourteenth 
day,  the  proportion  of  fibrin  had  risen,  in  the  first  to  4-5,  and  in  the  second  to  4-0;  these 
animals  had  no  food.  In  the  third  dog,  which  was  supplied  with  a  very  small  quantity  of 
food  daily,  the  same  condition  developed  itself  at  a  later  period ;  the  blood  on  the  four- 
teenth day  exhibiting  only  1-8  parts  of  fibrin,  but  on  the  twenty-second  day  presenting  3-3 
parts. — In  all  these  instances,  the  elevation  in  the  proportion  of  Fibrin  was  coincident  with 
Inflammatory  changes  in  the  stomach. 


ITS     CHARACTERS    IN    DISEASE.  201 

the  blood  of  pregnant  women,  seem  to  lead  to  the  conclusion  that,  during  the 
first  six  months,  the  Fibrin  is  below  the  normal  standard  ;  and  that  it  subse- 
quently varies,  usually  undergoing  an  augmentation  between  the  sixth  and 
seventh,  and  the  eighth  and  ninth  months.  There  is  also  a  diminution  in  the 
Corpuscles;  and  these  circumstances  combined  favour  the  production  of  the 
1  buft'y  coat'  (§  206).  These  observations  are  confirmed  by  those  of  MM.  Bec- 
querel  arid  Rodier. 

189.  It  appears  obvious,  from  what  has  been  just  stated,  that  the  increase  in 
the  quantity  of  Fibrin  is  not  dependent  upon  the  febrile  condition  which  is 
secondary  to  the  local  inflammation,  but  upon  the  Inflammation  itself.  This  con- 
clusion is  confirmed  by  the  interesting  fact  that,  in  idiopathic  Fever,  the  propor- 
tion of  Fibrin  is  diminished,  instead  of  undergoing  an  increase.  This  diminu- 
tion was  constantly  observed  by  Andral  in  the  premonitory  stage  of  Continued 
Fever;  in  some  instances  the  amount  was  no  more  than  1*6  parts  in  1000.  The 
proportion  of  Corpuscles  was  found  to  have  usually,  but  not  constantly,  under- 
gone an  increase;  as  had  also  that  of  the  solid  parts  of  the  Serum.  In  ordinary 
Continued  Fever,  in  which  there  was  no  evident  complication  from  local  disease, 
the  quantity  of  Fibrin  varied  from  4-2  to  2-2;  that  of  the  Corpuscles  from  185-1 
to  103 -6  (excluding  a  case  in  which  their  amount  was  only  82 '5,  which  was  that 
of  a  Chlorotic  female);  that  of  the  solid  matter  of  the  Serum,  from  98-7  to 
90-9  ;  and  that  of  the  Water  from  725-6  to  851-9.  Hence  the  quantity  of  solid 
matter  appears  to  be  usually  increased ;  but  the  peculiar  condition  of  the  blood 
in  this  disease  may  probably  be  stated  to  be  (so  far  as  regards  the  proportions  of 
its  principal  constituents)  a  diminution  of  the  Fibrin  in  proportion  to  the  Red 
Corpuscles.  When,  however,  a  local  Inflammatory  affection  developes  itself 
during  the  course  of  the  Fever,  the  amount  of  Fibrin  increases;  but  its  aug- 
mentation seems  to  be  kept-down  by  the  febrile  condition.  In  Typhoid  Fever,1 
the  decrease  in  the  proportion  of  Fibrin  is  much  more  decidedly  marked;  this 
does  not  depend  upon  abstinence ;  for  it  ceases  as  soon  as  a  favourable  change 
occurs  in  the  disease,  long  before  the  effect  of  food  could  show  itself.  In  the 
various  cases  examined  by  Andral,  the  blood  furnished  a  maximum  of  3-7  of 
fibrin,  and  a  minimum  of  0-9;  in  this  last  case,  the  typhoid  condition  existed  in 
extreme  intensity,  yet  the  patient  recovered.  The  proportion  of  Corpuscles 
varies  considerably ;  in  an  early  stage  of  the  disease  it  is  usually  found  to  be 
absolutely  high;  and  it  always  remains  high,  relatively  to  the  amount  of  fibrin. 
In  Typhoid  Fever,  then,  the  abnormal  condition  of  the  Blood,  in  regard  to  the 
disproportion  between  the  corpuscles  and  the  fibrin,  is  more  strongly  marked 
than  in  ordinary  continued  fever;  yet  the  usual  augmentation  of  fibrin  will  take 
place,  if  a  local  inflammation  developes  itself.  —  In  'putrid7  or  'malignant' 
fevers,  there  appears  to  be  a  very  marked  diminution,  not  only  in  the  fibrin,  but 
in  the  other  solid  constituents  of  the  blood ;  and  in  their  advanced  stages,  the 
blood  may  entirely  lose  its  power  of  coagulation.  Thus  in  a  case  of  l  typhus 
abdominalis/  in  which  the  blood  was  analysed  by  Simon,  he  found  only  112-5 
parts  of  solid  matter,  of  which  54  parts  were  albumen,  the  corpuscles  only  con- 
stituting 47 k  parts,  and  the  fibrin  being  altogether  deficient.  In  the  Exanthe- 
uiatous  Fevers,  it  does  not  appear  that  the  proportion  between  the  fibrin  and  the 
corpuscles  undergoes  so  striking  a  change,  as  in  ordinary  continued  fever;  but 
the  number  of  cases  examined  has  been  too  small  to  admit  of  decided  conclu- 
sions. It  is  evident,  however,  that  the  specific  Inflammations  proper  to,  and 
characteristic  of,  these  Fevers,  have  not  the  same  effect  in  occasioning  an  increase 
of  the  Fibrin,  as  an  intercurrent  Inflammation  of  an  extraneous  character. — It 
has  been  asserted  that  the  proportion  of  Fibrin  is  diminished  in  Scurvy;  but 
this,  from  the  analyses  of  MM.  Becquerel  and  Rodier,  Chatin  and  Bouvier,2  and 

1  M.  Andral  confines  this  term  to  the  species  characterised  by  ulceration  of  the  mucous 
follicles  of  the  intestinal  canal. 

»  "  Journ.  de  Chimie  Medicale,"  Mars.  1848. 


20*3  OF  THE   BLOOD; 

Mr.  Gr.  Busk,1  appears  not  to  be  the  case,  the  proportion  of  fibrin  being  rather 
above  than  below  the  normal  average.  In  Cholera,  however,  a  reduction  in  the 
coagulable  element  of  the  blood  seems  to  be  an  almost  constant  occurrence ;  and 
in  some  instances,  the  blood,  although  loaded  with  solid  matter,  has  scarcely 
coagulated  at  all.  Of  the  blood  drawn  during  life,  it  has  been  observed  that  the 
clot  is  loose  and  grumous,  often  not  shrinking  and  expelling  serum  ;  and  that 
this  change  presents  itself  in  a  degree  corresponding  to  the  severity  and  advanced 
stage  of  the  disease.  And  when  the  blood  has  been  removed  from  the  body 
after  death,  the  clots  have  been  found  loose  and  fragile  in  texture,  sometimes 
almost  semi-fluid.2  —  It  appears  from  the  experiments  of  Magendie,  that  one  of 
the  effects  of  a  diminution  in  the  proportion  of  Fibrin,  is  a  tendency  to  the  oc- 
currence of  Haemorrhage  or  of  Congestion,  either  in  the  parenchymatous  tissue, 
or  on  the  surface  of  membranes :  and  these  conditions  are  well  known  to  be  of 
frequent  occurrence,  as  complications  of  many  of  the  above  disorders.  A  marked 
diminution  of  Fibrin  was  noticed  also,  by  M.  Andral,  in  many  cases  of  Cerebral 
Congestion,  which  commences  with  headache,  vertigo,  and  tendency  to  epistaxis, 
and  not  unfrequently  passes  into  coma  and  apoplexy.  In  Apoplexy,  the  diminu- 
tion of  Fibrin  was  still  more  striking;  and  in  general,  there  was  found  to  be  an 
increase  of  the  Corpuscles.  In  one  instance,  the  quantity  of  Fibrin  on  the 
second  day  of  the  attack  was  found  to  have  fallen  to  1-9,  whilst  that  of  the  Cor- 
puscles had  risen  to  176-5;  but  on  the  third  day,  when  the  patient's  conscious- 
ness began  to  return,  the  quantity  of  Fibrin  was  3-5,  whilst  that  of  the  Cor- 
puscles had  fallen  to  137 -7.  It  would  seem  from  the  great  change  in  the  cha- 
racter of  the  Blood,  which  was  noticed  in  this  and  in  other  instances,  that  the 
want  of  due  proportion  between  the  Fibrin  and  the  Corpuscles  may  have  been 
the  cause,  rather  than  the  effect,  of  the  Apoplectic  attack.  In  a  case  of  Purpura 
Haemorrhagica,  in  which  the  blood  was  analysed  by  Koutier,3  the  proportion  of 
corpuscles  was  normal  (nearly  122  parts  in  1000),  whilst  the  fibrin  only  amounted 
to  0-9  parts  in  1000. 

190.  The  amount  of  Red  Corpuscles  seems  to  be  subject  to  greater  variation 
within  the  limits  of  ordinary  health,  than  is  that  of  fibrin.  In  the  condition 
which  is  ordinarily  termed  a  highly  sanguineous  temperament,  or  Plethora,  it  is 
chiefly  the  entire  mass  of  the  blood  that  undergoes  an  increase ;  but  whatever 
excess  there  may  be  in  the  proportion  of  its  solid  constituents,  this  affects  the 
Corpuscles  rather  than  the  fibrin.  Plethoric  persons  are  not  more  prone  to  In- 
flammation, than  are  those  of  weaker  constitution ;  but  they  are  liable  to  Con- 
gestion, especially  of  the  brain,  and  to  apoplexy  or  other  haemorrhage.  The 
effect  of  bleeding  in  diminishing  this  tendency  is  now  intelligible;  since  we 
know  that  loss  of  blood  reduces  the  proportion  of  corpuscles.  —  On  the  other 
hand,  in  that  temperament,4  which  when  exaggerated,  becomes  Anaemia,  there  is 
a  marked  diminution  of  the  Corpuscles;  this  temperament  may  lead  to  two 
different  conditions  of  the  system.  In  Chlorosis,  the  Red  corpuscles  are  di- 
minished, whilst  the  Fibrin  remains  the  same ;  so  that  the  clot,  though  small,  is 
firm,  and  not  unfrequently  exhibits  the  buffy  coat;  in  some  extreme  cases  of  this 
disease,  the  Corpuscles  have  been  found  as  low  as  27.  The  influence  of  the 
remedial  administration  of  Iron,  in  increasing  the  quantity  of  Corpuscles,  was 
rendered  extremely  perceptible  by  Andral's  analyses ;  in  one  instance,  after  iron 
had  been  taken  for  a  short  time,  the  proportion  of  Corpuscles  was  found  to  have 
risen  from  49-7  to  64-3;  whilst  in  another,  in  which  it  had  been  longer  con- 
tinued, it  had  risen  from  46  6  to  95'7.  On  the  other  hand,  Bleeding  reduced 

1  "  Library  of  Medicine,"  vol.  v.  p.  90. 

a  See  Dr.  Parkes's  "  Researches  into  the  Pathology  and  Treatment  of  the  Asiatic  01 
Algide  Cholera,"  pp.  32,  73. 

8  «'  Gazette  des  Hopitaux,"  torn.  vi.  No.  90. 

*  The  term  lymphatic  has  been  applied  to  this  temperament;  by  which  term  was  meant 
»  predominance  of  lymph  in  the  absorbent  vessels. 


ITS     CHARACTERS     IN     DISEASE.  203 

Ftill  lower  the  proportion  of  Corpuscles ;  thus  in  one  instance,  their  amount  was 
found,  on  a  second  bleeding,  to  have  sunk  from  62-8  to  49.  The  full  proportion 
of  fibrin  in  the  blood  of  Chlorotic  patients,  seems  to  account  for  the  infrequency 
of  Haemorrhage  in  them ;  whilst  it  also  leads  us  to  perceive  that  they  mav  be, 
equally  with  others,  the  subjects  of  acute  Inflammation,  which  we  know  to  be 
the  fact.  But  a  diminution  of  Corpuscles  may  coexist  with  a  diminution  in  the 
amount,  or  in  the  degree  of  elaboration,  of  the  fibrin ;  and  this  condition  seems 
to  be  characteristic  of  Scrofula.  Andral  has  noticed  a  diminution  in  the  pro- 
portion of  Red  Corpuscles  in  other  Cachectic  states,  resulting  from  the  influence 
of  various  depressing  causes  on  the  nutritive  powers ;  as  in  a  case  of  Diabetes 
Mellitus,  in  which  the  patient  was  much  exhausted  j  in  a  case  of  Aneurismal 
dilatation  of  the  Heart  inducing  Dropsy;  and  in  several  cases  of  Cachexia 
Saturnina.  The  proportion  of  Red  Corpuscles  seems  constantly  to  undergo  a 
marked  diminution  in  Scurvy  :  and  has  been  found,  in  some  cases  of  this  disease, 
as  low  as  in  intense  Anaemia.  The  same  may  be  said  of  the  advanced  stage  of 
Bright's  disease  of  the  Kidney,  and  of  '  Leucocythaemia/  A  very  rapid  disin- 
tegration of  the  Red  Corpuscles  appears  sometimes  to  take  place,  when  a  morbid 
poison  is  present  in  the  blood,  or  when  its  composition  has  been  seriously  affected 
by  the  loss  of  its  other  constituents.  Thus  Dr.  C.  J.  B.  Williams '  mentions  a 
case  of  Albuminuria  proving  fatal  in  six  days,  with  effusion  of  pus  into  the 
joints  the  day  before  death,  in  which  the  colouring  matter  was  found  to  be  dis- 
solved in  the  liquor  sanguinis,  scarcely  any  perfect  corpuscles  being  left.  He 
has  also  observed  a  similar  total  destruction  of  the  blood-discs  in  a  case  of 
malignant  scarlatina  with  purpura;  and  has  met  with  indications  of  a  partial 
destruction  of  them  in  acute  purpura  connected  with  jaundice,  and  in  cases  of 
functional  derangement  of  the  liver. 

191.  A  marked  increase  in  the  proportion  of  the  Colourless  Corpuscles  has 
been  frequently  observed  in  the  blood  of  Inflammatory  subjects;  this  increase  is 
not,  however,  so  characteristic  of  the  Inflammatory  state  as  some  have -supposed; 
for  it  is  by  no  means  constant  in  that  condition,  and  it  is  frequently  seen  in  very 
different  states  of  the  system  (§  212).  Attention  has  recently  been  drawn  by 
Prof.  J.  H.  Bennett2  to  a  condition  of  the  Blood,  which  is  especially  charac- 
terized by  a  marked  excess  of  these  bodies,  and  which  he  has  designated  by  the 
term  Leucocythcemia  (white-cell-blood).  This  condition  has  been  detected  in 
the  blood  of  a  considerable  number  of  individuals  suffering  under  disease  (most 
commonly  enlargement)  of  the  Spleen,  Liver,  and  Lymphatic  glands,  either  sepa- 
rately or  in  conjunction;  but  it  has  not  yet  been  determined  how  far  it  is 
constantly  associated  with  any  of  these  abnormal  conditions.  In  all  cases  in 
which  such  blood  has  been  analyzed,  its  specific  gravity  has  been  found  very  low, 
and  the  total  amount  of  solids  small  (being  in  one  instance  119  parts  in  1000) ; 
but  the  fibrin  is  almost  invariably  above  the  average,  having  in  one  instance 
risen  to  7 '08.  The  total  amount  of  corpuscles  is  considerably  reduced,  having 
ranged  in  six  analyses  between  49-7  and  101-6,  the  average  having  been  82-36; 
and  so  large  a  proportion  of  the  whole  mass  was  in  some  instances  determined  by 
the  microscope  (no  means  being  at  present  known  of  physically  separating  these 
two  orders  of  bodies)  to  be  of  the  colourless  kind,  that  the  amount  of  red  cor- 
puscles must  have  been  exceedingly  small.  The  proportion  of  solids  in  the  serum 
does  not  seem  to  undergo  any  decided  alteration.  No  marked  change  in  the 
condition  of  the  blood  could  be  detected,  during  the  progress  of  any  of  the  cases 
which  were  under  observation  for  long  periods ;  and  the  circumstances  under 
which  the  commencement  of  this  morbid  perversion  occurs,  are  still  quite  unknown 
When  the  colourless  corpuscles  are  present  in  very  large  amount,  they  give  to  the 
colourless  coagula  found  in  the  heart  and  large  vessels  after  death,  a  dull  whitish 
colour,  and  render  them  friable. 

1  "  Principles  of  Medicine,"  3d  Am.  Ed.,  p.  50. 

2  See  his  successive  Papers  in  the  "  Edinb.  Monthly  Journal,"  for  1851,  and  his  Treatise 
"On  Leucocythsemia." 


1!04  OF    THE     BLOOD. 

192.  The  quantity  of  Albumen  in  the  blood  seems  to  vary  less  than  that  of 
most  of  its  other  constituents.  The  proportion  which  it  bears  to  the  water  of  the 
serum,  is  of  course  elevated  by  anything  which  diminishes  the  latter;  and  thus  we 
find  it  high  in  cholera  after  profuse  discharges  of  fluid  from  the  intestinal  canal,  and 
in  other  cases  in  which  there  has  been  an  unusual  drain  upon  the  liquid  part  of 
the  blood,  provided  that  the  albumen  do  not  pass  oif  with  it,  as  sometimes  hap- 
pens. Where  some  special  cause  is  in  operation,  which  favours  the  escape  of  the 
albumen  from  the  circulating  current  (as  happens  in  various  forms  of  Albumin- 
uria,  but  especially  in  the  advanced  stage  of  'Bright's  disease'),  the  amount  of 
albumen  in  the  serum  is  reduced  below  the  normal  standard.  Thus  Dr.  Christi- 
son  found  the  entire  solids  of  the  serum  to  be  reduced  in  some  instances  to  55  or 
even  52  parts  in  1000,  his  estimate  of  their  normal  amount  being  834;  and  he 
found  the  specific  gravity  of  the  serum  to  fall  as  low  as  1020  or  even  1019,  the 
normal  standard  being  from  1027  to  1031.  According  to  Andral,  the  diminution 
in  the  amount  of  Albumen  in  the  Serum  is  exactly  proportioned  to  the  quantity 
contained  in  the  Urine.1 — The  proportion  of  fatty  matter  in  the  serum,  and 
especially  of  the  cholesterin,  has  been  found  by  MM.  Becquerel  and  Rodier  to 
undergo  an  increase  at  the  commencement  of  most  acute  diseases;  and  they  have 
also  observed  an  increase  of  fat,  and  especially  of  cholesterin  in  chronic  diseases 
of  the  liver,  in  Bright' s  disease  of  the  kidney,  and  in  tuberculosis.  The  quantity 
of  fat  in  the  blood  sometimes  undergoes  such  an  augmentation,  as  to  give  to  the 
serum  a  constant  '  milkiness.'  This  has  been  observed  by  Marcet  in  a  case  of 
diabetes,  by  Traill  in  hepatitis,  by  Christison  in  dropsy,  icterus,  and  nephritis,  by 
Zanarelli  in  pneumonia,  and  by  Sion  in  mammary  abscess.  In  Dr.  Traill's  case, 
the  whole  amount  of  solid  matter  in  the  serum  was  211  parts  in  1000;  as  much  as 
157  parts  being  albumen,  whilst  45  were  fat.  In  Zanarelli's  case,  the  blood  con- 
tained so  small  a  proportion  of  red  corpuscles,  that  it  seemed  milky  when  it  first 
flowed  ;  and  it  did  not  undergo  a  regular  coagulation,  but  merely  separated  into 
a  thicker. and  a  thinner  portion.  This  blood  only  contained  95  parts  of  solid 
constituents  in  1000;  and  10  parts  of  these  consisted  of  fatty  matter,  and  9 
parts  of  extractive  and  salines;  so  that  the  whole  amount  of  fibrin,  corpuscles, 
and  albumen  was  only  76  parts.  In  Dr.  Siou's  case,  also,  the  blood  itself  was 
quite  milky ;  it  underwent  no  coagulation  ;  and  only  a  very  small  quantity  of 
colouring  matter  was  deposited,  when  it  was  allowed  to  stand.  This  blood  was 
found  by  Lecanu  to  contain  206  parts  of  solid  constituents  in  1000 ;  but  of  these 
no  less  than  117  parts  were  fat,  the  remainder  consisting  of  albumen  (64  parts), 
and  of  extractive  and  salines  (25  parts).  No  fibrin  could  be  found,  and  the 

1  A  case  is  related  by  Andral,  under  this  head,  which  affords  an  interesting  exemplifica- 
tion of  the  general  facts  that  have  been  attained  by  his  investigation.  A  woman  who  had 
been  suffering  from  Erysipelas  of  the  face,  and  had  lost  blood  both  by  venesection  and  by 
leeches,  became  the  subject  of  Albuminuria.  The  blood  drawn  at  this  time  exhibited  a 
considerable  diminution  in  the  proportion  of  Corpuscles,  as  well  as  of  Albumen, — a  fact 
which  the  previous  loss  of  blood  fully  accounted  for.  After  a  short  period,  during  which 
she  had  been  allowed  a  fuller  diet,  another  experimental  bleeding  exhibited  an  increase  in 
the  proportion  of  Corpuscles.  Some  time  afterwards,  when  the  Albumen  had  disappeared 
from  the  Urine,  some  more  blood  was  drawn  ;  and  it  was  then  observed  that  the  Albumen 
of  the  Serum  had  returned  to  its  due  proportion,  but  that  the  Corpuscles  had  again 
diminished,  whilst  there  was  a  marked  increase  in  the  quantity  of  Fibrin.  This  alteration 
was  fully  accounted-for  by  the  fact,  that,  in  the  interval,  several  Lymphatic  ganglia  in 
the  neck  had  been  inflamed  and  had  suppurated ;  ..nd  that  the  patient  had  been  again 
placed  on  very  low  diet.  •'  Thus,"  observes  Andral,  "  we  were  enabled  to  give  a  complete 
explanation  of  the  remarkable  oscillations  which  were  presented,  in  the  proportion  of  the 
different  elements  of  the  blood  drawn  at  three  different  times  from  the  same  individual ; 
and  thus  it  is  that,  the  more  extended  are  our  enquiries,  the  more  easy  does  it  become  to 
refer  to  general  principles  the  causes  of  all  those  changes  in  the  composition  of  the  blood, 
which,  from  the  frequency  and  rapidity  with  which  they  occur,  seem  at  first  sight  to  baffle 
all  rules,  and  to  take  place,  as  it  were,  at  random.  In  the  midst  of  this  apparent  dis- 
order, there  is  but  the  fulfilment  of  laws ;  and  in  order  to  obtain  these,  it  is  only  necessary 
to  strip  the  phenomena  of  their  complications,  and  reduce  them  to  their  simplest  form." 


ITS     CHARACTERS     IN    DISEASE.  205 

quantity  of  hsemato-globulin  was  inappreciable.1  Such  a  fluid  must  be  considered 
rather  as  chyle  than  as  blood  ;  and,  in  the  entire  absence  of  coagulating  power, 
corresponds  rather  with  chyle  when  first  absorbed,  than  with  that  which  is  usually 
transmitted  by  the  thoracic  duct  (§  135). — Little  is  known  with  certainty  regard- 
ing the  variations  of  the  alkaline  salts  in  the  blood  in  different  diseases.  The 
analyses  which  have  been  made,  however,  are  considered  by  Prof.  Lehman 2  to 
indicate  that  in  very  severe  inflammations  they  are  very  much  diminished ; 
whilst  they  are  much  increased  in  the  acute  exanthemata  and  in  typhus,  in 
dysentery,  Bright* s  disease,  and  all  forms  of  dropsy  and  hydrasmia;  and  are  often 
doubled  in  quantity  in  diseases  depending  upon  malarious  influences,  such  as 
endemic  dysentery,  malignant  forms  of  intermittent  fever,  &c.  Although  a  large 
quantity  of  saline  matter  passes-off  from  the  blood  in  Cholera,  yet  the  proportion 
of  water  discharged  is  so  much  greater,  that,  as  appears  from  the  analyses  of 
Dr.  G-arrod,  the  per-ceutage  of  salines  in  the  blood  is  rather  increased  than 
diminished.3 

193.  The  proportion  of  Water  in  the  blood  will  of  course  vary  reciprocally 
with  that  of  the  solid  constituents ;  and  will  be  especially  augmented  when  there 
is  a  marked  diminution  in  the  amount  of  red  corpuscles.     When  there  is  an  ex- 
cessive and  constant  drain  upon  it,  as  in  diabetes,  there  is  at  the  same  time  such 
a  craving  for  liquids,  as  causes  the  quantity  ingested   to  supply  the  deficiency 
occasioned  by  its  removal  j  so  that  the  mass  of  the  blood  is  not  thereby  dimi- 
nished.    In  Cholera,  however,  the  case  is  different;  for  in  that  form   of  the 
disease  attended  with  copious  discharges,  the  reduction  in  the  liquid  constituent 
of  the  blood  becomes  very^  marked,  however  large  may  be  the  quantity  of  water 
ingested.     This  is  remarkably  shown  by  the  analyses  of  Lecanu,4  who  found  the 
proportion   of  solid  constituents  in  some  instances  even  to   exceed  that  of  the 
water. 

Solid  constituents 251         380        340        520 

Water 749         670        660        480 

No  such  degree  of  reduction  has  been  observed  by  others ;  still  the  general  fact 
is,  that  the  proportion  of  water  is  considerably  diminished. 

194.  That  the  Blood  is  subject  to  a  great  variety  of  other  morbid  alterations, 
which  are  sometimes  the  causes,  and  sometimes  the  results,  of  Disease,  cannot 
be  for  a  moment  doubted.     But  our  knowledge  of  the  nature  of  these  changes 
is  as  yet  very  insufficient.     The   great   amount   of  attention  which   is  being 
directed  by  Chemical  Pathologists  to  the  subject,  however,  will  doubtless  ere 
long  produce  some  important  results.  —  Among  the  most  frequent  causes  of  de- 
pravation in  the  character  of  this  fluid,  we  must  undoubtedly  rank  the  retention, 
in  the  Circulating  current,  of  matters  which  ought  to  be  removed  by  the  Excre- 
tory processes.     We  shall  hereafter  see,  that  a  total  interruption  to  the  excietion 
of  Carbonic  Acid  by  the  lungs,  will  occasion  death  in  the  course  of  a  very  few 
minutes  (§  326);  and  even  when  only  a  slight  impediment  is  offered  to  it,  eo 
that  the  quantity  of  carbonic  acid  always  contained  in  arterial  blood  is  augmented 
to  but  a  small  degree,  a  feeling  of  discomfort  and  oppression,  increasing  with 
the  duration  of  the  interruption,  is  speedily  produced.     The  results  of  the  re- 
tention of  the  materials  of  the  Biliary  and  Urinary  excretions  will  be  hereafter 
considered  (CHAP.  IX.);  and  at  present  it  will  be  only  remarked,  that  such  re- 
tention is  a  most  fertile  source  of  slight  disorders  of  the  system,  that  it  is  largely 
concerned  in  producing  many  severe  diseases,  and  that,  if  incomplete,  it  will 
most  certainly  and  rapidly  bring-about  a  fatal  result.  —  The  most  remarkable 
cases  of  depravation  of  the  Blood,  by  the  introduction  of  matters  from  without, 

1  This  remarkable  case  is  cited  in  Simon's  "  Animal  Chemistry,"  vol.  i.  p.  333,  from  the 
"  Lancette  Fransaise,"  1835,  No.  49. 

*  "  Physiological  Chemistry"  (Cavendish  Society's  Ed.),  vol.  ii.  p.  262. 
1  "London  Journal  of  Medicine,"  May,  1849 

*  "  Etudes  Chimiques  sur  le  Sang,"  p,  106 


206          OF  THE  BLOOD;   ITS   VITAL   PROPERTIES, 

are  those  in  which  these  substances  act  as  ferments,  exciting  such  Chemical 
changes  in  the  constitution  of  the  fluid,  that  its  whole  character  is  speedily 
changed,  and  its  vital  properties  are  altogether  destroyed.  Of  such  an  occur- 
rence, we  have  characteristic  examples  in  the  severe  forms  of  Typhoid  fever, 
commonly  termed  malignant ;  in  Plague,  Glanders,  Pustule  Maligne,  and  seve- 
ral other  diseases;  in  some  of  which  we  can  trace  the  direct  introduction  of  the 
poison  into  the  blood,  whilst  in  others  we  must  infer  (from  the  similarity  of 
result)  that  it  has  been  introduced  through  some  obscure  channel,  probably  the 
lungs.  Tfre  evidence  which  we  possess  of  the  '  intoxication '  of  the  Blood,  in 
these  and  other  cases,  derived  from  the  perversion  of  the  nutritive  operations 
which  it  induces,  will  be  considered  in  the  next  Section. 

3.    Of  the  Vital  Properties  of  the  Blood,  and  its  Relations  to  the  Living 

Organism. 

195.  It  cannot  be  doubted  that  the  perfect  and  regular  performance  of  the 
various  actions  to  which  the  Blood  is  subservient,  is  dependent  upon  the  admix- 
ture of  its  principal  components  in  their  due  proportions,  and  upon  its  freedom 
from  deleterious  matters,  whether  formed  within  the  system,  or  introduced  into 
the  circulating  current  from  without.     And  it  is  not  difficult  to  see  how  any  con- 
siderable  alteration  which  affects  its  physical  conditions  merely,  may  thereby 
produce  a  most  serious  disturbance  in  the  regularity  of  the  circulation,  and  in 
the  functions  to  which  it  ministers.     Thus  it  has  been  shown  by  the  experiments 
of  Poisseuille,1  that  a  certain  degree  of  viscidity  is  favourable  to  the  motion  of 
liquids  through  capillary  tubes;  a  thin  solution  of  sugar  or  gum  being  found  to 
traverse  them  more  readily  than  pure  water  will  do.     Hence  any  serious  altera- 
tion in  the  proportion  of  the  organic  and  saline  compounds   dissolved  in  the 
liquor   sanguinis,  and    especially   in    that   of  the    Fibrin    (on    which    the   vis- 
oidity  of  the  blood  appears  chiefly  to  depend),  might  be  expected  to  produce 
obstruction  in  the  capillary  circulation,  and  to  favour  transudation  of  the  fluid 
portion  of  the  blood ;  and  the  numerous  experiments  of  Magendie  (Op.  cit.) 
saem  to  favour  this  view,  although  they  are  far  from  manifesting  that  character 
for  accuracy  and  discrimination,  which  would  be  required  to  afford  an  authorita- 
tive sanction   to   it.      A   much   more  determinate   influence,  however,  must   be 
exerted  upon  the  Red  Corpuscles,  by  any  cause  which  seriously  affects  the  specific 
gravity  of  the  liquor  sanguinis  (§  158);  and  the  perfect  elaboration  of  the  Al- 
buminous constituent  of  the  serum  has  been  shown  to  be  requisite,  to  prevent  it 
from  copiously  transuding  the  membranous  walls  of  the  vessels  which  it  tra- 
verses (§  183).  — These  and  other  physical  and  chemical  relations  of  the  Blood, 
however,  are  quite  subordinate  to  its  Vital  reactions ;  and  it  is  into  them  that 
we  have  now  to  inquire. 

196.  There  are  only  two  constituents  of  the  circulating  Blood,  which  can  be 
considered  as  being  themselves  endowed  with  vital  properties;  these  are,  the 
Fibrin  and  the  Corpuscles.     The  remainder  of  its  components  can  scarcely  be 
looked-upon  in  any  other  light  than  as  chemical  compounds,  which   are  to   be 
rendered  subservient  to  the  nutritive  and  other  operations  of  the  living  tissues 
in  virtue  of  their  vitality,  or  which  have  already  discharged  their  duty  in   the 
system.     To  attribute  vital  properties  to  a  substance  which,   like   Fibrin,   is 
usually  in  a  state  of  solution,  has  been  considered  by  some  Physiologists  as  an 
absurdity;  but  there  seems  no  adequate  reason,  why  liquids,  as  well  as  solids, 
should  not  possess  vital  attributes;  and  the  power  exhibited  by  fibrin,  of  spon- 
taneously passing  (under  certain  conditions)  into  an  organized  texture,  of  how- 
ever low  a  type,  cannot  be  legitimately  considered  in  any  other  light  than  as  a 
vital  endowment  (§  197).     That  the  Corpuscles,  however,  both  Red  and  Colour- 
less, are  living  cells,  and  that,  like  other  cells,  they  possess  vital  endowments  pecu- 

1  See  M.  Magendie's  "  Le9ons  sur  les  Phe'nomenes  Physique  de  la  Vie,"  torn.  iv.  p.  57. 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.     207 

liar  to  themselves,  is  not  now  questioned  by  any  one  ;  and  their  separate  history 
forms  no  unimportant  element  in  the  general  *  Life  of  the  Blood/  whilst  it  can 
scarcely  be  doubted,  from  the  facts  already  stated,  that  it  has  a  most  important 
relation  to  the  Life  of  the  body  generally.  —  Before  proceeding,  however,  to  in- 
quire into  the  nature  of  this  relation,  our  attention  may  be  advantageously 
directed  to  that  remarkable  change  in  the  state  of  the  blood  when  withdrawn 
from  the  vessels  of  the  living  body,  which  is  commonly  known  as  its  *  coagulation.' 
This  term,  however,  as  applied  to  the  blood  en  masse,  is  quite  inappropriate; 
since,  as  we  shall  presently  see,  the  coagulation  essentially  consists  in  the  passage 
of  the  fibrin  alone  from  the  soluble  to  the  solidified  state;  and  this  component 
scarcely  forms  more  than  one  hundredth  part  of  the  whole  solid  matter  of  the 
circulating  fluid.  All  the  phenomena  attendant  upon  this  process,  and  the  con- 
ditions by  which  it  is  influenced,  have  been  made  the  subject  of  very  careful 
study,  both  by  Chemists  and  Physiologists ;  but  it  must  be  admitted  that  they 
throw  very  little  light  upon  the  vital  relations  of  the  Blood  to  the  Organism  at 
large,  these  being  only  sustained  whilst  it  is  circulating  in  a  fluid  state,  and  being 
interfered-with  by  anything  that  favours  its  passage  into  the  form  which  it 
assumes  when  withdrawn  from  the  body. 

197.  The  Coagulation  of  the  Blood,  then,  consists  in  the  new  arrangement  of  its 
constituents,  which  takes  place  when  it  is  drawn  from  the.  vessels  and  is  left  to 
itself,  or  when  the  body  itself  dies  (§  157).  This  new  arrangement  essentially 
depends  upon  the  passage  of  the  Fibrin  from  the  soluble  to  the  insoluble  state,  in 
which  it  forms,  not  an  amorphous  coagulum,  but  a  network  of  fibres  more  or  less 
definitely  marked-out;  in  the  meshes  of  which  network  are  included  the  Red 
corpuscles,  usually  grouped-together  in  columnar  masses,  resembling  piles  of 
money  (Fig.  54).  The  Crassamentum  or  Clot  thus  formed,  gradually  acquires  a 
degree  of  firmness  proportioned  to  the  amount  of  Fibrin  which  it  contains,  and  to 
the  degree  of  its  elaboration ;  and  it  undergoes  a  progressive  contraction,  by  which 
the  Albuminous,  Saline  and  Extractive  matters,  still  dissolved  in  the  water,  are 
more  or  less  completely  expelled  from  it,  constituting  the  Serum.  This  sepa- 
ration will  not  occur,  however,  if  the  coagulation  take  place  in  a  shallow  vessel ; 
nor  if  the  amount  of  Fibrin  should  be  small,  or  its  vitality  low.  A  homogeneous 
mass,  deficient  in  firmness,  presents  itself  under  such  circumstances;  though  the 
solid  part  of  this  may  pass  into  a  state  of  more  complete  condensation  after  the 
lapse  of  a  certain  time. — That  the  coagulation  is  due  to  the  Fibrin,  and  that  the 
Corpuscles  do  not  take  any  active  share  in  the  process,  appears  from  several  con- 
siderations.1 A  microscopical  examination  of  the  Clot  shows,  that  it  has  the 
same  texture  with  Fibrin  when  coagulating  by  itself ;  the  Corpuscles  clustering- 
together  in  the  interspaces  of  the  network,  and  not  being  uniformly  diffused 
through  the  whole  mass.  Their  specific  gravity  being  greater  than  that  of  the 
Fibrin,  they  are  usually  most  abundant  at  the  lower  part  of  the  clot;  and  the 
upper  surface  is  sometimes  nearly  colourless,  especially  when  the  coagulation  has 
taken  place  slowly ;  yet  this  upper  part  is  much  firmer  than  the  lower,  showing 
that  the  Fibrin  alone  is  the  consolidating  agent.  If,  after  the  complete  subsi- 
dence of  the  Corpuscles,  a  little  of  the  colourless  Liquor  Sanguinis  be  skimmed- 
off,  it  will  undergo  complete  coagulation,  forming  a  colourless  clot ;  as  was  long 
ago  shown  by  Hewson.  The  same  fact  may  be  experimentally  demonstrated,  by 
the  use  of  methods  which  effect  an  artificial  separation  of  the  Fibrin  from  the 
Corpuscles.  Thus  Miiller  placed  the  blood  of  a  Frog,  diluted  with  water  (or 
still  better,  with  a  very  thin  syrup),  on  a  paper  filter  of  sufficiently  fine  texture 

1  It  is  remarkable  that  this  doctrine,  clearly  established  by  the  older  Physiologists,  and 
especially  by  Hewson,  should  ever  have  been  put  aside,  even  temporarily,  for  the  un- 
tenable hypothesis  that  the  coagulation  of  the  blood  is  due  to  a  running-together  of  its 
red  corpuscles.  —  For  an  admirable  summary  of  the  history  of  opinion  on  this  subject, 
see  Mr.  Gulliver's  Introduction  to  his  Edition  of  Hewson's  works*(published  by  the  Syden 
ham  Society). 


208         OF   THE   BLOOD;   ITS   VITAL   PROPERTIES, 

to  keep-back  the  Corpuscles;  and  the  Liquor  Sanguinis,  having  passed  through 
the  filter  completely  unmixed  with  them,  presented  a  distinct  coagulum,  al- 
though, from  the  diluted  state  of  the  fluid,  this  does  not  possess  much  consis- 
tency. Owing  to  the  more  minute  size  of  the  Blood-discs  of  warm-blooded  ani- 
mals, this  experiment  cannot  be  so  readily  performed  with  their  blood.  So, 
again,  if  fresh-drawn  blood  be  continually  stirred  with  a  stick,  the  Fibrin  will 
adhere  to  it  in  strings  during  its  coagulation;  and  the  Red  corpuscles  will 
be  left  suspended  in  the  serum,  without  the  slightest  tendency  to  coagulate. 
Moreover,  if  a  solution  of  any  salt,  that  has  the  property  of  retarding  the  co- 
agulation (such  as  carbonate  of  potash  or  sulphate  of  soda),  be  added  to  the 
blood,  the  Corpuscles  will  have  time  to  sink  to  the  lower  stratum  of  the  fluid, 
before  the  clot  is  formed ;  the  greater  part  of  the  crassamentum  is  then  entirely 
colourless,  and  is  found  by  the  microscope  to  contain  few  or  no  red  particles. 
It  will  be  presently  shown,  however,  that  the  difference  of  specific  gravity  is  by 
no  means  the  only  cause  of  the  separation  of  the  Corpuscles  from  the  Liquor 
Sanguinis  (§  205). 

198.  That  the  Coagulation  of  the  Blood  is  not,  as  some  have  supposed,  a 
proof  of  its  death,  but  is  rather  an  act  of  vitality,  appears  evident  from  the  in- 
cipient organization  which  may  be  detected  even  in  an  ordinary  clot ;  and  still 
more  from  the  fact,  that,  if  the  effusion  of  Fibrin  take  place  upon  a  living  sur- 
face, its  conversion  into  a  fibrous  solid  is  the  first  act  in  the  production  of  solid 
tissues,  which  become  constituents  of  the  living  fabric;  for  it  seems  absurd  to 
maintain  that  the  Blood  dies,  in  order  to  assume  a  higher  form.  The  degree  of 
regularity  with  which  this  fibrillation  takes  place,  and  the  completeness  of  the 
fibres  which  are  formed  by  it,  seem  to  depend  especially  upon  two  conditions, — 
1st,  the  degree  of  previous  elaboration  to  which  the  fibrin  has  been  subjected, — 
and  2nd,  the  properties  of  the  surface  on  which  it  takes  place.  Thus  we  find 
the  coagulum  of  some  specimens  of  blood  to  be  much  firmer,  and  its  fibrous 
structure  to  be  more  distinct,  than  that  of  others ;  the  fibrillation  of  the  fibrinous 
fluid  of  inflammatory  blood  being  usually  more  complete  than  that  of  ordinary 
blood ;  while  that  of  the  fluid  of  plastic  exudations,  formerly  known  as  'coagulable 
lymph/  is  still  more  distinct  than  that  of  blood  effused  en  masse.  That  the 
Blood  may  itself  become  organized,  like  plastic  exudations  of  "  coagulable  lymph," 
(a  doctrine  which,  though  maintained  by  Hunter,  has  been  subsequently  denied,) 
seems  to  have  been  conclusively  proved  by  the  researches  of  Dr.  Zwicky,1  on  the 
changes  occurring  in  the  clots  of  blood  which  form  in  blood-vessels,  above  the 
points  where  they  have  been  tied ;  for  he  has  traced  the  successive  stages  of  the 
metamorphosis  of  the  coagulum  into  connective  tissue,  and  the  formation  of  ves- 
sels in  its  substance ;  the  whole  process  taking  place  exactly  as  in  an  inflamma- 
tory exudation,  and  the  blood-corpuscles  exerting  no  other  influence  upon  it,  than 
that  of  slightly  retarding  it.  Similar  observations  have  been  also  made  by  Mr. 
Paget.2  —  But  further,  the  fibrillation  takes  place  far  more  perfectly  when  the 
fibrinous  fluid  is  effused  on  a  living  surface,  than  when  it  is  spread-out  over  dead 
matter ;  and  thus  it  happens  that  fibrinous  effusions  are  much  more  completely 
converted  into  fibrous  tissue  within  the  living  body,  and  in  immediate  contact 
with  living  tissue,  than  they  ever  are  when  removed  from  it.  A  marked  differ- 
ence may  be  observed  in  this  respect,  between  the  superficial  and  the  central 
portions  of  a  blood-clot  which  has  been  effused  in  the  substance  of  the  living 
solids ;  for  it  is  always  in  the  former,  that  the  organizing  process  is  most  advanced, 
a  firm  and  distinct  fibrous  membrane  being  often  found  on  the  exterior  of  such 
clots,  whilst  their  interior  is  soft  and  amorphous.3  Generally  speaking,  the  fibril- 
1  "  Die  Metamorphose  des  Thrombus;"  Zurich,  1846. 

5  See  liis  'Lectures  on  the  Processes  of  Repair  and  Reproduction,'  in  the  "Medical 
Gazette"  for  1849,  vol.  xliii.  p.  1066 ;  and  his  "  Surgical  Pathology,"  pp.  120,  et  seq., 
Am.  Ed. 

3  See  Dr.  G.  Burrows,  in  "  Medical  Gazette,"  1835 ;  and  Mr.  Prescott  Hewett,  in 
"  Medico-Chirurg.  Trans.,"  vol.  xxviii. 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.    209 

lation  is  more  perfect,  the  more  slowly  it  takes  place ;  and  the  higher  the  pre- 
vious vitalization  of  the  fibrine,  the  longer  is  it  before  it  changes  its  state.  Thus 
the  coagulation  of  sthenic  inflammatory  blood,  which  produces  a  clot  of  remark- 
able firmness,  is  much  longer  in  taking-place  than  the  coagulation  of  ordinary 
blood;  whilst  the  coagulation  of  the  blood  of  cachectic  subjects,  which  take's 
place  very  rapidly,  is  feeble  and  imperfect.  The  plastic  effusions  poured-out 
from  the  blood  in  these  two  opposite  conditions,  partake  of  the  character  of  the 
blood  itself;  those  of  the  inflammatory  blood  of  a  previously  healthy  subject 
being  converted  into  fibrous  membranes  of  considerable  firmness,  which  are  sub- 
sequently penetrated  by  blood-vessels,  and  become  regularly-organized  tissues; 
whilst  those  proceeding  from  the  blood  of  cachectic  subjects  frequently  undergo 
a  certain  degree  of  organization  with  great  rapidity,  but  do  not  go-on  to  the  same 
perfection,  and  speedily  degenerate.1 

199.  Instances  occasionally  present  themselves,  in  which  the  Blood  does  not 
coagulate  after  death,  or  coagulates  very  imperfectly.     It  was  affirmed  by  Hunter2 
that  no  coagulation  occurs  in  the  blood  of  animals  hunted  to  death,  or  of  those 
killed  by  lightning,  by  electric  shocks,  or  by  blows  upon  the  epigastrium ;  and 
this  statement  has  been  generally  received  upon  his  authority.     It  is  far,  how- 
ever, from  being  constantly  true ;  for  Mr.  Gulliver  has  collected  numerous  cases 
in  which  coagulation  was  found  to  have  taken  place  in  the  blood  of  animals  killed 
in  each  of  these  modes;  in  some  of  them,  however,  the  coagulation  was  very 
imperfect.3     It  is  not  improbable  that  some  of  the  instances  of  apparent  absence 
of  coagulation,  were  really  cases  of  retarded  coagulation  (§  200) ;  and  Dr.  Polli 
goes  so  far  as  to  maintain,  that  the  complete  absence  of  coagulating  power  is  a 
phenomenon  which  has  no  real  existence.     He  states  that  he  has  never  met  with 
an  instance,  in  which  the  blood,  when  left  to  itself,  and  duly  protected  from  ex- 
ternal destructive  influences,  did  not  coagulate  before  becoming  putrid ;  and  that 
lie  has  more  than  once  found  blood  to  coagulate,  which  had  been  taken  in  a  fluid 
state  from  the  vessels  thirty-six  or  forty-eight  hours  after  death.4     Still  there 
seems  no  reasonable  doubt  that  non-coagulation  may  occur,  when  the  blood  has 
been  previously  subjected  to  conditions  which  affect  the  vitality  of  its  fibrin. 
Such  appears  to  be  the  case,  for  example,  when  death  occurs  from  Asphyxia,  as 
by  hanging,  drowning,  or  breathing  of  irrespirable  gases;5  and  the  same  has 
been  observed  in  cases  of  poisoning  by  hydrocyanic  acid,  in  which  asphyxia  was 
probably  the  immediate  cause  of  death.     In  certain  diseased  states,  again,  we 
have  seen  that  the  coagulating  power  seems  to  be  completely  deficient  (§  189). 

200.  The  length  of  time  which  elapses  before  Coagulation,  and  the  degree  in 
which  the  clot  solidifies,  vary  considerably;  in  general,  they  are  in  the  inverse 
proportion  to  each  other.     Thus,  if  a  large  quantity  of  blood  be  withdrawn  from 
the  vessels  of  an  animal  at  the  same  time,  or  within  short  intervals,  the  portions 
that  last  flow  coagulate  much  more  rapidly,  but  much  less  firmly,  than  those  first 
obtained.     In  blood  drawn  during  Inflammatory  states,  again,  the  coagulation  is 
usually  slow,  but  the  clot  is  preternaturally  firm,  especially  at  its  upper  part, 
where  the  Buffy  coat  (§  205)  or  colourless  stratum  of  fibrin,  gradually  contracts, 
and  produces  the  '  cup/  which  may  be  generally  considered  to  indicate  a  high 
degree  of  inflammation.     Although  the  Blood  from  the  body  coagulates  (except 
under  the  peculiar  circumstances  just  stated),  whether  it  be  kept  at  rest  or  in 

i  gee  especially  Mr.  Dalrymple's  Memoirs  "  On  the  rapid  organization  of  Lymph  in 
Cachexia,"  in  the  "  Med.  Chir.  Trans.,"  vol.  xxiii. ;  and  "  On  the  early  organization  of 
Coagula  and  mixed  fibrinous  effusions  under  certain  conditions  of  the  system,"  Op.  cit. 
vol.  xxvii. 

3  "  The  Works  of  John  Hunter,"  edited  by  James  F.  Palmer,  vol.  iii.  pp.  34,  114. 

3  See  "Edinb.  Med.  and  Surg.  Journ."  Oct.,  1848,  pp.  367,  418;  and  his  Edition  of 
"  Hewson's  Works,"  pp.  20,  21. 

4  "Annali  Universal!,"  1845;  and  "Banking's  Abstract,"  vol.  ii.  p.  337. 

*  See  Dr.  J.  Davy's  "Physiological  and  Anatomical  Researches,"  vol.  ii.  p.  192. 

14 


210          OF  THE   BLOOD;   ITS  VITAL  PROPERTIES, 

motion,  whether  its  temperature  be  high  or  low,  and  whether  it  be  excluded  from 
the  air,  or  be  admitted  to  free  contact  with  the  atmosphere,  yet  its  coagulation 
may  be  accelerated  or  retarded  by  variation  in  these  conditions.  —  If  the  blood 
be  continually  agitated  in  a  bottle,  its  coagulation  is  delayed,  though  it  will  at 
last  take  place  in  shreds  or  insulated  portions ;  but  that  rest  is  not  the  cause  of 
its  coagulation  (as  some  have  supposed),  is  proved  by  the  fact  that,  if  a  portion 
of  blood  be  included  between  two  ligatures  in  a  living  vessel,  it  will  remain  fluid 
for  a  considerable  time  j l  as  it  also  will  when  effused  into  the  midst  of  living 
tissues,  or  kept  in  a  state  of  stagnation  in  parts  affected  with  inflammation. 
Thus  Mr.  Gulliver,  besides  other  instances,  mentions  a  remarkable  case  witnessed 
by  himself,  in  which  a  collection  of  blood  which  had  been  effused  in  consequence 
of  a  bruise  on  the  loins,  was  found  uucoagulated  when  let-out  twenty-eight  days 
afterwards;  it  measured  five  ounces,  was  as  liquid  as  blood  just  drawn  from  a 
vein,  and  showed  the  normal  characters  when  examined  microscopically;  and  it 
coagulated  in  a  cup  in  less  than  thirty  minutes  (Op.  cit.  p.  17).  And  Mr.  Paget 
mentions  that  he  has  known  the  blood  remain  fluid  in  the  vessels  of  an  inflamed 
part,  though  in  a  state  of  complete  stagnation,  for  as  long  as  three  days.2  — 
Again,  the  coagulation  is  accelerated  by  moderate  warmth,  the  natural  heat  of 
the  body  from  which  the  blood  is  taken  appearing  to  be  most  favourable  to  it ; 
but  the  coagulating  power  appears  to  be  destroyed  by  a  temperature  of  about 
150°,  blood  heated  to  that  point  remaining  permanently  fluid.  (Gulliver,  Op. 
cit.  pp.  4,  5).  On  the  other  hand,  the  coagulation  is  retarded  by  cold ;  but  the 
coagulating  power  is  not  destroyed  even  by  extreme  cold ;  for  if  blood  be  frozen 
immediately  that  it  is  drawn,  it  will  coagulate  on  being  thawed. — Moreover  it  is 
accelerated  by  exposure  to  air,  but  it  is  not  prevented  by  complete  exclusion  from 
it,  as  is  proved  by  its  taking  place  in  a  vacuum,  or  in  a  shut  sac  within  the  dead 
body :  complete  exclusion  from  the  air,  however,  retards  the  change ;  as  may  be 
easily  shown  by  causing  blood  to  flow  into  a  vessel  containing  oil,  which  will 
form  an  impervious  coating  on  its  surface,  and  will  occasion  the  coagulation  to 
take  place  so  slowly,  that  the  red  particles  have  time  to  subside,  and  the  upper 
Btratum  of  the  clot  is  colourless.3 — The  effect  of  the  addition  of  strong  solutions 
of  neutral  salts  to  fresh  blood,  is  usually  to  retard,  and  sometimes  even  to  pre- 
vent, its  coagulation ;  and  the  same  effect  is  produced  by  many  vegetable  sub- 
stances, particularly  those  of  the  narcotic  and  sedative  class,  such  as  opium,  bel- 
ladonna, aconite,  hyoscyamus,  digitalis,  and  tea  or  coffee  in  strong  infusion.4 
The  action  of  most  of  those  substances,  however,  which  preserve  the  fluidity  of 
the  blood,  only  continues  during  such  time  as  their  solutions  retain  a  certain 
strength ;  for  if  they  be  diluted,  coagulation  will  then  take  place,  although  in 
most  cases  less  perfectly  than  it  would  have  done  at  first.  There  appears  to  be 
no  limit  to  the  time  during  which  the  coagulation  may  be  thus  postponed ;  thus 
Mr.  Gulliver5  mentions  that  he  has  kept  horse's  blood  fluid  with  nitre  for  fifty- 

1  The  testimony  of  all  experimenters  is  in  accordance  on  this  point,  although  they  differ 
as  to  the  length  of  time  that  elapses  before  coagulation  commences.     Mr.  Gulliver  states 
that  out  of  many  trials  made  by  him,  the  coagulation  commenced  within  two  hours  in 
only  a  few  instances ;  more  commonly,  three,  four,  or  five  hours  elapsed  before  any  clot 
was  formed ;  and  in  one  instance,  the  coagulation  was  incomplete  at  the  end  of  twenty- 
four  hours.     In  all  these  experiments,  the  blood  coagulated  in  the  course  of  a  few  minutes, 
when  withdrawn  from  the  living  vessel. — See  Mr.  Gulliver's  edition  of  "  Hewson's  Works," 
p.  23. 

2  "Lectures  on  Surgical  Pathology,"  p.  213,  Am.  Ed. 

8  Dr.  Babington  in  "  Medico-Chirurgical  Transactions,"  vol  xvi. 

4  See  Dr.  J.  Davy's  "Anatomical  and  Physiological  Researches,"  vol.  ii.  pp.  101,  102; 
and  Mr.  Praeter's  "Experimental  Inquiries  in  Chemical  Physiology,"  pp.  59,  63,  &c.     A 
copious  table  of  the  results  of  their  experiments  is  given  in  Mr.  AncelPs  '  Lectures  on  the 
Physiology  and  Pathology  of  the  Blood,'  in  the  "  Lancet"  for  Dec.  21,  1839. 

5  Mr.  Gulliver  considers  this  fact,  together  with  the  occurrence  of  coagulation  on  the 
thawing  of  blood  which  has  been  frozen  whilst  yet  fluid,  as  conclusive  against  the  vital 
character  of  the  act ;  remarking  that  if  we  believe  the  coagulation  to  be  an  effect  of  life, 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.     211 

seven  weeks,  and  that  it  still  readily  coagulated  when  diluted  with  water  (Op. 
cit.  p.  12). — It  is  not  so  difficult,  therefore,  as  it  might  otherwise  seem,  to  give 
credit  to  the  statement  of  Dr.  Polli,  that,  in  a  case  witnessed  by  himself,  com- 
plete coagulation  of  the  blood  did  not  take  place  until  fifteen  days  after  it  had 
been  withdrawn  from  the  body ;  and  that  fifteen  days  more  elapsed,  before  putre- 
faction commenced  in  it.  The  upper  four-fifths  of  the  clot  were  colourless,  the 
red  corpuscles  occupying  only  the  lowest  fifth.  It  is  additionally  remarkable, 
that  the  patient  (who  was  suffering  under  acute  pneumonia),  being  bled  very 
frequently  during  the  succeeding  week,  the  blood  gradually  lost  its  indisposition 
to  coagulate.1 

201.  It  has  been  maintained  by  some  observers,  that  a  certain  amount  of  heat 
is  liberated  during  Coagulation ;  but  this  idea  would  seem  to  have  been  founded 
on  a  fancied  analogy  between  coagulation  and  freezing ;  and  it  is  negatived  by 
the  careful    observations  of  Hunter,  Schroeder  Yan  der  Kolk,  J.  Davy,  and 
Denis. — Again,  it  has  been  asserted  that  the  act  of  coagulation  is  attended  by 
the  extrication  of  a  small  quantity  of  carbonic  acid ;  but  there  is  no  sufficient 
proof  that  blood  in  coagulating  gives  out  more  carbonic  acid,  than  it  ordinarily 
does  by  exposure  to  the  air  (§  179).     Moreover,  it  has  been  shown  by  the  ex- 
periments of  Sir  H.  Davy2  and  Dr.  J.  Davy,3  that  no  effect  is  produced,  either 
in  accelerating  or  retarding  coagulation,  by  placing  blood  in  an  atmosphere  of 
nitrogen,  nitrous  gas,  nitrous  oxide,  or  carbonic  acid;  and  it  has  been  found  that 
coagulation  still  takes  place,  even  if  the  blood  be  agitated  with  carbonic  acid. 

202.  The  vital  condition  of  the  walls  of  the  blood-vessels  appears  to  have  an 
important  influence  upon  the  fluidity  of  the  Blood.     Thus  it  has  been  found  by 
Sir  A.  Cooper  and  Mr.  Thackrah,  that  whilst  blood  enclosed  in  a  living  vein  re- 
tained its  fluidity  for  some  time  (§  200),  blood  similarly  enclosed  in  a  dead  vein, 
the  atmosphere  being  completely  excluded,  coagulated  in  a  quarter  of  an  hour. 
Moreover,  inflammation  of  the  walls  of  the  blood-vessels  (which  is  a  condition 
of  depressed  vitality,  CHAP.  vui.  Sect.  3)  promotes  the  coagulation  of  the  Blood 
which  they  contain ;  and  thus  it  is,  that  the  trunks  both  of  arteries  and  veins 
frequently  become  choked-up  by  coagula.4     Moreover,  although  there  can  be  no 
doubt  that  a  large  proportion  of  the  loose  fib rinous  masses  found  in  the  heart  and 

we  must  admit  that  we  can  freeze  and  pickle  the  life  (Op.  cit.  p.  21).  No  such  admission, 
however,  is  necessary.  We  do  not  freeze  and  pickle  the  life ;  but  we  simply  preserve  the 
vital  properties  of  the  substance,  by  preventing  it  from  undergoing  spontaneous  change ; 
thus  doing  the  same  for  the  blood,  as  may  be  done  for  seeds,  eggs,  and  even  highly -or- 
ganized bodies,  which  may  be  kept  in  a  state  of  '  dormant  vitality '  for  unlimited  periods, 
by  cooling  or  drying  them,  or  by  secluding  them  from  the  atmosphere.  (See  "  Princ.  of 
Gen.  Physiol."  Am.  Ed.) 

1  "Gazetta  Medica  di  Milano,"  Genn.  20,  1844;  cited  in  Mr.  Paget's  'Report'  in  "Brit, 
and  For.  Med.  Rev.,"  vol.  xix.  p.  252. 

a  "Researches  on  Nitrous  Oxide,"  pp.  380 — 1. 

3  "Anatomical  and  Physiological  Researches,"  vol.  ii.  p.  71. 

4  It  was  observed  by  Hunter,  and  has  been  frequently  noticed  since,  that  when  ampu 
tation  is  performed  on  account  of  spontaneous  gangrene  of  the  lower  extremities,  there  is 
no  jet  of  blood  from  the  divided  arterial  trunk,  which  is  obstructed  by  coagulum  far  above 
the  line  to  which  the  gangrene  has  extended ;  and  there  is  good  reason  to  regard  the 
gangrene  as,  in  these  cases,  the  result  of  a  previous  arteritis,  which  has  thus  put  a  stop 
to  the  circulation  through  the  limb.     (For  evidence  in  support  of  this  doctrine,  see  the 
"Essai  sur  les  Gangrenes  spontanges"  of  M.  Fran£ois,  Paris,  1832.) — The  author,  whilst 
a  pupil  at  the  Middlesex  Hospital  in  1835,  witnessed  a  remarkable  case  of  Phlebitis  (ap- 
parently brought-on  by  suppressed  menstruation),  in  which  both  femoral  veins  were  suc- 
cessively affected,  and  in  which  death  took  place  suddenly  when  the  patient  appeared  to 
be   recovered  from  the  attack ;  on  post-mortem  examination,  not  only  the  iliac  trunks, 
but  also  the  vena  cava,  for  some  distance  above  their  junction,  were  found  to  be  completely 
obstructed  by  nearly-colourless  coagula  adherent  to  their  walls  ;  so  that  the  wonder  was, 
how  any  return  of  blood  could  have  taken  place  from  the  pelvis  and  lower  extremities. 
There  seemed  no  reason  to  attribute  the  formation  of  these  coagula  to  the  introduction  of 
pus  into  the  venous  circulation. 


212          OF  THE   BLOOD;   ITS  VITAL  PROPERTIES, 

large  vessels  after  death,  are  the  result  of  post-mortem  coagulation,  yet  there  is 
often  adequate  evidence,  derived  from  the  symptoms  previously  observed,  and 
from  the  appearances  presented  by  the  coagula  themselves,  that  the  coagulation 
has  commenced  during  life;  and  in  all  cases  of  this  kind,  there  has  been  a 
marked  depression  of  vital  power  for  some  time  previous  to  the  final  extinction 
of  life.  Again,  it  was  found  by  Schroeder  Van  der  Kolk,1  that  if  the  substance 
of  the  brain  and  spinal  marrow  be  broken-down,  coagulation  of  the  blood  takes 
place  whilst  it  is  still  moving  within  the  vessels ;  clots  being  found  in  them,  even 
within  a  few  minutes  after  the  operation.  Further,  that  the  contact  of  a  dead 
substance  promotes  coagulation,  even  in  the  living  and  actively-moving  blood,  is 
shown  by  the  experiments  of  Mr.  Simon,  who  carried  a  single  thread  (by  means 
of  a  very  fine  needle)  transversely  through  an  adjacent  artery  and  vein  of  a  dog, 
and  left  it  there,  so  that  it  might  cut  the  stream,  for  a  period  of  from  twelve  to 
twenty-four  hours;  the  consequence  of  which  was,  that  a  coagulum  was  formed 
upon  the  thread,  more  or  less  completely  obstructing  the  vessel.  There  was, 
however,  a  marked  difference  in  the  coagula  formed  within  the  artery  and  the 
vein  respectively,  which  may  be  attributed  to  the  difference  in  the  quality  of  the 
fibrin  in  the  blood  of  the  two  vessels  (§  180),  or  to  the  difference  in  the  rate  of 
its  motion,  or  to  both  causes  conjointly;  for  the  thread  which  traversed  the 
artery  usually  presented  a  l  vegetation'  on  its  surface,  sometimes  as  large  as  a 
grain  of  wheat,  always  of  a  pyramidal  shape,  with  its  base  attached  to  the  thread, 
and  its  apex  down-stream ;  whilst  the  venous  coagulum  was  a  voluminous  black 
clot,  chiefly  collected  on  that  side  of  the  thread  remotest  from  the  heart.2 

203.  Again  the  contact  of  dead  animal  matter  with  the  Blood  appears  to 
promote  the  coagulation  of  its  fibrin  in  a  very  remarkable  degree ;  occasioning 
coagula  to  form,  whilst  it  is  yet  actively  moving  in  the  vessels  of  the  living  body. 
Thus  M.  Dupuy  found  that  the  injection  of  cerebral  substance  into  the  veins  of 
an  animal,  occasioned  its  death  almost  as  instantaneously  as  if  prussic  acid  had 
been  administered ;  the  circulation  being  rapidly  brought  to  a  stand,  by  the  for- 
mation of  voluminous  clots  in  the  heart  and  large  vessels.  These  experiments 
were  repeated  and  confirmed  by  M.  de  Blainville.3 — The  same  effect  is  produced 
with  more  potency,  when  the  substance  injected  is  rather  undergoing  degradation, 
than  actually  dead;  for  it  then  seems  to  act  somewhat  after  the  manner  of  a 
ferment,  producing  a  marked  diminution  in  the  vitality  of  the  solids  and  fluids 
with  which  it  may  be  brought  in  contact.  Such  is  pre-eminently  the  case  with 
pus,  as  was  long  ago  observed  by  Hunter,  and  as  Mr.  H.  Lee  has  since  determined 
more  precisely.  It  was  found  by  the  latter,  that  healthy  blood  received  into  a 
cup  containing  some  offensive  pus,  coagulated  in  two  minutes;  whilst  another 
sample  of  the  same  blood,  received  into  a  clean  vessel  of  similar  size  and  shape, 
required  fifteen  minutes  for  its  complete  coagulation.  When  he  injected  putrid 
pus  into  the  jugular  vein  of  a  living  ass,  coagulation  took  place  so  instantane- 
ously as  to  produce  an  immediate  obstruction  to  the  current  of  blood,  so  that  the 

1  "  Comment,  de  Sanguinis  Coagulatione,"  Groeningen,  1820. 

5  "  Lectures  on  General  Pathology,"  p.  48,  Am.  Ed. — Mr.  Simon  applies  this  fact  to  the  ex- 
planation of  the  '  vegetations '  which  so  commonly  present  themselves  upon  the  valves  of 
the  heart,  in  cases  of  rheumatic  endocarditis ;  maintaining  that  they  are  simple  deposits 
from  the  fibrin  of  the  blood,  which  is  unusually  abundant  in  this  condition.  This  doctrine 
can  only  be  substantiated,  however,  by  a  careful  microscopic  examination  of  these  sub- 
stances ;  and  if  they  should  be  proved  to  have  the  simple  constitution  which  Mr.  Simon 
imputes  to  them,  the  fact  will  in  no  degree  set  aside  (as  he  seems  to  consider  it  must  do) 
the  existence  of  endocardial  inflammation,  but  will  rather  confirm  it,  since  the  deposition 
of  fibrin  on  those  particular  spots  is  likely  to  be  specially  determined  by  inflammation  of 
the  subjacent  membrane. 

3  "Gazette  Me"dicale,"  1834,  p.  521. — There  is  no  reason  to  suppose  that  cerebral  sub- 
stance possesses  a  more  special  influence,  than  would  be  exerted  by  any  other  tissue  which 
could  be  as  easily  mixed- up  with  the  circulating  current.  The  presence  of  a  piece  of  flesh 
or  of  the  clot  of  blood,  as  Prof.  Buchanan  has  shown,  often  suffices  to  determine  the 
coagulation  of  fibrin  in  a  solution  from  which  it  would  not  otherwise  have  separated. 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.          213 

vessel  at  once  acquired  a  cord-like  character;  and  in  this  mode,  the  pus  was 
usually  prevented  from  finding  its  way  into  the  general  current  of  the  circulation. 
Whilst  it  thus  remains  circumscribed  by  a  coagulum  of  blood,  the  pus  so  intro- 
duced seems  to  produce  no  other  constitutional  disturbance,  than  is  attributable 
to  the  local  injury;  but  if  the  circumscription  should  be  incomplete,  and  the  pus 
should  be  carried  into  the  general  circulation,  it  becomes  a  source  of  extensive 
mischief,  determining  the  formation  of  abcesses  in  various  parts,  and  producing  a 
most  depressing  influence  on  the  system  at  large.1  The  effect  of  certain  animal 
poisons  of  a  still  more  potent  nature,  when  introduced  into  the  current  of  the 
circulation  (as  by  the  bite  of  venomous  serpents),  appears  to  be,  like  that  of  a 
high  temperature,  the  entire  destruction  of  the  coagulating  power  of  the  blood,  as 
well  as  of  the  vital  endowments  of  the  tissues  generally  (§  194). 

204.  The  proportions  of  Serum  and  Clot  which  present  themselves  after  coagula- 
tion, are  liable  to  great  variation,  independently  of  the  amount  of  the  several 
ingredients  characteristic  of  each;  for  the  crassamentum  may  include,  not  only 
the  fibrin  and  red  corpuscles,  but  also  a  large  proportion  of  the  serum,  entangled 
(as  it  were)  in  its  substance.     This  is  particularly  the  case  when  the  coagulation 
is  rapid;  and  the  clot  then  expels  little  or  none  of  it  by  subsequent  contraction. 
On  the  other  hand,  if  the  coagulation  be  slow,  the  particles  of  fibrin  usually  seem 
to  become  more  completely  aggregated,  the  coagulum  is  denser  at  first,  and  its 
density  is  greatly  increased  by  subsequent  contraction.     When  a  firm  fresh  clot 
is  removed  from  the  fluid  in  which  it  is  immersed,  its  contraction  is  found  to 
go-on  increasing  for  24  or  even  48  hours,  serum  being  squeezed-out  in  drops 
upon  its  surface ;  and  in  order,  therefore,  to  form  a  correct  estimate  of  the  relative 
proportions  of  Crassamentum  and  Serum,  the  former  should  be  cut  into  slices,  and 
laid  upon  bibulous  paper,  that  the  latter  may  escape  from  it  as  freely  and  com- 
pletely as  possible. — According  to  the  experiments  of  Mr.  Thackrah,2  coagulation 
takes  place  sooner  in  metallic  vessels  than  in  those  of  glass  or  earthenware,  and  the 
•quantity  of  serum  separated  is  much  less ;  in  one  instance,  the  proportion  of  serum 
to  clot  was  as  10  to  24|,  when  the  blood  coagulated  in  a  glass  vessel;  whilst  a 
portion  of  the  same  blood,  coagulating  in  a  pewter  vessel,  gave  only  10  of  serum 
to  175  of  clot.     The  specific  gravity  of  Blood  is  no  measure  of  its  coagulating 
power ;  for  a  high  specific  gravity  may  be  due  to  an  excess  in  the  amount  of  cor- 
puscles, which  form  the  heaviest  part  of  the  blood;  and  may  be  accompanied  by 
a  diminution  in  the  quantity  of  fibrin,  which  is  the  coagulating  element 

205.  The  surface  of  the  Crassamentum  not  unfrequently  exhibits  in  certain 
disordered  conditions  of  the  blood,  a  layer  that  is  nearly  free  from  colour;  and 
this  is  known  as  the  Buffy  Coat.     Its  presence  has  been  frequently  regarded  as  a 
sign  of  the  existence  of  Inflammation,  indicating  an  undue  predominance  of  fibrin ; 
but  this  idea  is  far  from  being  correct,  since,  as  will  presently  appear  (§  206),  it 
may  result  from  an  opposite  condition  of  the  blood.     A  similar  colourless  layer  is 
usually  observable,  when  the  coagulation  of  the  blood  has  been  retarded  by  the 
addition  of  agents  that  have  the  power  of  delaying  it  (§  200) ;  and  since,  in 
inflammatory  states  of  the  system,  the  blood  is  generally  long  in  coagulating,  it 
has  been  supposed  that  the  separation  of  the  red  particles  from  the  fibrinous  part 
of  the  clot  is  due  to  this  cause  alone.     It  was  long  since  pointed-out  by  Dr.  Ali- 
son,3 however,  that  this  explanation  is  insufficent,  for  the  two  following  reasons: — 
"  1.   The  formation  of  the  buffy  coat,  though  no  doubt  favored,  or  rendered  more 
complete,  by  slow  coagulation,  is  often  observed  in  cases  where  the  coagulation  is 
more  rapid  than  usual ;  and  the  colouring-matter  is  usually  observed  to  retire 
from  the  surface  of  the  fluid  in  such  cases,  before  any  coagulation  has  commenced. 
2  The  separation  of  the  fibrin  from  the  colouring-matter  in  such  cases  takes 

1  See  Mr.  H.  Lee's  excellent  Treatise  "  On  the  Origin  of  Inflammation  of  the  Veins,  and 
on  Purulent  Deposits." 

'  "Enquiry  into  the  Nature  and  Properties  of  the  Blood,'*  2nd  edit.,  p.  66. 
8  "  Outlines  of  Physiology,"  3d  edit.  p.  89. 


FIG.  63. 


£14    OF  THE  BLOOD;  ITS  VITAL  PROPERTIES, 

place  in  films  of  blood,  so  thin  as  not  to  admit  of  a  stratum  of  the  one  being  laid 
above  the  other ;  they  separate  from  each  other  laterally,  and  the  films  acquire  a 
speckled  or  mottled  appearance,  equally  characteristic  of  the  state  of  the  blood 
with  the  buffy  coat  itself."  Now  we  have  already  seen  that  the  red  corpuscles 
of  healthy  blood  have  a  tendency  to  aggregate-together  in  piles  and  masses;  and 
it  has  been  pointed-out  by  Prof.  H.  Nasse1  and  Mr.  Wharton  Jones,2  that  this 
tendency  is  greatly  augmented  in  inflammatory  blood,  so  that  the  corpuscles  run- 
together  into  little  clumps  often  visible  to  the  naked  eye,  and  adhere  to  each 
other  with  considerable  tenacity  (Fig.  63).  Further,  it  has  been  shown  by  Mr. 

Gulliver,3  that  the  subsidence  of  the  red 
corpuscles  is  more  rapid  in  inflammatory 
than  it  is  in  healthy  blood,  and  that  their 
rate  of  sinking  increases  with  their  aggre- 
gation ;  so  that  whilst  they  sink  about  an 
eighth  of  an  inch  during  the  first  two 
or  three  minutes,  they  sink  through  five 
or  six  times  that  space  in  the  next  interval 
of  the  same  length.  That  the  quickness 
with  which  they  thus  aggregate  in  the 
lower  part  of  the  clot,  does  not  depend 
(in  the  case  of  inflammatory  blood)  upon 
the  mere  facility  with  which  they  sink, 
was  further  determined  by  the  use  of 
means  which  tended  to  diminish  or  in- 
crease their  aggregation ;  thus  it  was  found 
that  the  addition  of  weak  saline  solutions, 

Microscopic  appearance  of  a  drop  of  Inflam-    by  which  the  liquor  sanguinis  is  attenuated, 
matory  Blood;  the  red  corpuscles  lose  their    but  which  diminish  the  mutual  attraction 

circular  form,  and  adhere  together ;  the  white    Of    the    red   corpuscles,   partially  or   com 


p< 

buffy  coat,  in  blood  which  exhibited  it 
strongly  when  left  pure,  even  though  its  coagulation  was  considerably  retarded 
thereby;  on  the  other  hand,  the  addition  of  mucilage  with  a  small  quantity  of 
saline  matter,  the  effect  of  which  is  to  promote  the  aggregation  of  the  corpuscles, 
tended  to  develope  the  bufiy  coat  by  increasing  the  rate  at  which  they  sink.  Now 
as  it  has  been  found  that  liquor  sanguinis  deprived  of  its  corpuscles  coagulates 
more  slowly  than  unaltered  blood,  it  does  not  seem  improbable,  as  Mr.  Gulliver 
has  remarked,  that  this  separation  of  the  two  components  of  the  crassamentum, 
which  determines  the  formation  of  the  buffy  coat,  is  partly  the  cause,  rather  than 
the  consequence,  of  the  slowness  of  the  coagulation  of  inflammatory  blood. — It  is 
in  the  bufiy  coat  of  inflammatory  blood,  that  we  see  the  clearest  indications  of 
organization  ever  presented  by  the  circulating  fluid.  The  fibrous  network  is 
frequently  extremely  distinct ;  and  it  commonly  includes  a  large  number  of  colour- 
less corpuscles  in  its  meshes ;  these,  indeed,  being  sometimes  so  numerous,  that  it 
is  almost  entirely  composed  of  them.  In  its  Chemical  Composition,  the  bufly 
coat  of  inflammatory  blood  appears  to  be  peculiar;  containing  a  larger  or  smaller 
amount  of  the  substance,  readily  soluble  in  boiling  water,  which  is  considered  by 
Mulder  to  be  the  tritoxide  of  protein. 

206.  When  the  'buff'  arises  from  other  causes,  however,  its  appearance  is  less 
characteristic.  It  appears  from  the  researches  of  Andral,  that  the  usual  condi- 
tion of  its  production  is  an  increase  in  the  quantity  of  Fibrin  relatively  to  the 
rod  corpuscles,  and  not  a  simple  augmentation  of  fibrin.  This  increase  may  occur 

1  "  Das  Blut,"  cited  in  Benin's  "  Anatomie  Generate"  (trad.  par.  Jourdan).  torn  i.  p.  468. 

3  'Report  on  Inflammation,'  in  "Brit,  and  For.  Med.  Rev.,"  vol.  xvii.  p.  567. 

3  See  his  Memoir  'On  the  Buffy  Coat  of  the  Blood,'  in  the  "  Edin.  Med.  and  Surg. 
Journ."  No.  165;  and  his  edition  of  "Hewson's  Works,"  p.  41. 


AND     ITS     RELATION    TO    THE    LIVING    ORGANISM.    215 

in  two  ways  ; — either  by  an  absolute  increase  in  the  fibrin,  the  amount  of  the  cor- 
puscles remaining  unchanged,  or  not  being  augmented  in  the  same  proportion ; — 
or  by  a  diminution  of  the  corpuscles,  the  quantity  of  fibrin  remaining  the  same,  or 
not  diminishing  in  the  same  proportion.  Hence  in  severe  Chlorosis,  in  which 
the  latter  condition  is  strongly  developed  (§  180),  the  '  buffy  coat '  may  be  as 
well  marked,  as  in  the  severest  Inflammation.1  Unless  the  composition  of  the 
blood  be  altered  in  one  of  these  two  ways,  we  are  assured  by  Andral  that  the 
1  buffy  coat '  is  never  formed ;  the  influence  of  circumstances  which  favour  it  not 
being  sufficient  to  produce  it  when  acting  alone.  The  absence  of  these  circum- 
stances may  prevent  it,  however,  when  it  would  otherwise  have  been  formed  : 
thus,  when  the  blood  flows  slowly  the  'buff'  is  not  properly  produced,  because 
the  slow  discharge  gives  one  portion  time  to  coagulate  before  another,  and  only 
the  blood  last-drawn  furnishes  the  fibrin  at  the  upper  part  of  the  vessel ;  again, 
in  a  deep  narrow  vessel,  the  'buff'  will  form  much  more  decidedly  than  in  a 
broad  shallow  one,  because  the  thickness  of  the  fibrinous  crust  will  be  greater. 

207.  It  appears,  then,  from  the  foregoing  facts,  that  we  must  regard  the 
Coagulation  of  the  blood  as  essentially  dependent  upon  the  vital  properties  of  its 
fibrin :  the  tendency  to  aggregation  which  is  exhibited  by  the  Red  Corpuscles, 
having  no  special  part  in  it,  except  when  that  tendency  is  abnormally  augmented, 
and  then  only  influencing  the  relative  situations  of  the  two  components  of  the 
clot.  The  deficiency  in  coagulating  power,  by  which  the  blood  is  sometimes 
marked,  must  be  attributed  to  the  want  of  due  elaboration  in  the  Fibrin  alone, 
or  to  the  destruction  of  its  vital  endowments  by  some  agent  which  has  a  noxious 
influence  upon  it :  of  the  former  condition  we  seem  to  have  an  example  in  such 
a  case  as  that  already  cited  (§  192),  in  which  the  circulating  fluid  consisted  of  a 
very  crude  chyle ;  of  the  latter,  in  those  diseased  states  in  which  we  can  trace 
the  operation  of  a  poison  upon  blood  that  was  previously  healthy,  as  when 
asphyxia  has  occasioned  the  retention  of  carbonic  acid  generated  within  the 
system,  or  when  the  materies  morbi  of  cholera  or  some  malignant  fever  has  been 
introduced  into  the  circulation.  But  it  would  be  by  no  means  fair  to  attribute 
the  noxious  influence  of  such  poisons  solely  to  their  power  of  destroying  the 
coagulability  of  the  blood-fibrin,  for  it  is  obviously  exerted  in  many  other  ways ; 
and  it  is  probable  that  the  same  agency  which  kills  the  fibrin,  exerts  a  similar 
destructive  power  on  the  vitality  of  the  corpuscles,  and  on  that  of  the  tissues 
through  which  the  poisoned  blood  circulates.  —  But  whilst  we  attribute  the 
coagulating  power  of  the  Blood  to  the  vital  endowments  of  the  fibrin,  we  can 
scarcely  fail  to  perceive  that  the  exercise  of  this  power  is  kept  in  check  (so  to 
speak)  by  the  vital  endowments  of  the  living  tissues  with  which  it  is  in  contact. 
For,  as  we  have  seen,  the  main  condition  of  coagulation  is  the  diminution  or 

1  The  records  of  Medicine  scarcely  furnish  a  more  notable  example  of  the  pernicious 
influence  of  theories  founded  upon  a  shallow  Empiricism,  and  of  the  superiority  of  the 
Rational  practice  based  on  a  knowledge  of  the  real  facts  of  the  case,  than  is  afforded  by 
the  contrast  between  the  former  and  the  present  treatment  of  Chlorosis.  Whilst  the  notion 
prevailed  that  the  « buffy  coat'  is  a  sign  of  Inflammation,  and  that  the  most  potent  remedy 
for  Inflammation  is  loss  of  blood,  patients  already  reduced  to  a  state  of  anaemia,  who  com- 
plained of  pain  in  the  left  hypochondrium,  palpitation,  &c.,  were  bled  over  and  over  again, 
every  withdrawal  of  blood  of  course  seriously  increasing  the  mischief,  by  producing  a 
further  reduction  in  the  proportion  of  red  corpuscles  (§  178).  The  Author  well  remembers 
that,  when  a  pupil  in  the  Bristol  Infirmary  in  the  years  1833-4,  he  was  repeatedly  directed 
by  the  estimable  Senior  Physician  (long  since  dead),  to  draw  eight,  ten,  or  twelve  ounces  of 
blood  from  patients  in  this  condition;  and  that  the  crassamentum,  after  coagulation,  often 
resembled  a  small  island  floating  in  an  ocean  of  serum.  Yet,  because  this  minute  clot 
exhibited  the  buffy  coat,  the  bleeding  was  considered  to  be  «  orthodox'  practice,  and  the 
obstinacy  of  the  symptoms  was  attributed  to  the  severity  of  the  disease.  If  M.  Andral 
had  made  no  other  contribution  to  Medical  Science,  than  the  demonstration  of  the  re.il 
nature  of  this  condition  of  the  blood,  and  of  the  influence  of  further  depletion  in  promot- 
ing it,  he  would  have  rendered  a  most  essential  service  to  the  multitudes  of  females  who 
are  unfortunate  enough  to  suffer  from  this  kind  of  deterioration  of  their  vital  fluid. 


216     OF  THE  BLOOD;  ITS  VITAL  PROPERTIES, 

cessation  of  their  agency,  either  by  the  withdrawal  of  blood  from  the  body,  or 
by  the  death  of  the  organism  enclosing  it,  or  by  the  lowered  vitality  of  the 
tissues  through  which  it  moves  (§  202) ;  whilst  mere  stagnation  exerts  but  a 
secondary  influence  upon  it  (§  200).  And  thus  we  seem  entitled  to  say,  that 
the  liquid  condition  of  the  fibrin  is  a  result  of  a  balance  of  forces  between  the 
fibrin  and  the  living  tissues,  those  of  the  former  tending  to  its  solidification, 
whilst  those  of  the  latter  maintain  its  fluidity;  but  that  if  the  latter  should  be 
deficient,  the  former  come  into  uncontrolled  action,  and  expend  themselves  in 
the  production  of  a  lowly-organized  tissue,  the  higher  vitalization  of  which  de- 
p^nds  upon  subsequent  operations  (§  198).  The  source  of  this  vital  endowment 
of  the  Fibrinous  constituent  of  the  blood,  must  be  looked-for  in  the  operations 
to  which  the  crude  albuminous  pabulum  is  subjected,  after  its  first  reception  into 
the  system. 

208.  Of  the  particular  purposes  which  are  served  by  the  Fibrin  of  the  blood 
in  the  vital  economy  of  the  system  at  large,  it  must  be  confessed  that  we  have 
but  little  positive  knowledge.  The  idea  has  been  entertained  by  many  Physio- 
logists (including  the  Author  of  this  treatise),  that  the  fibrin  is  that  element  of 
the  blood  which  is  immediately  drawn-upon  in  the  operations  of  nutrition ;  being 
the  intermediate  stage  between  the  crude  albumen  and  the  solid  tissues.  This 
opinion  rested  in  part  upon  the  current  doctrine,  that  fibrin  is  the  constituent  of 
Muscle;  and  in  part  upon  the  assumption,  that,  as  fibrin  is  more  endowed  with 
vital  properties  than  any  other  of  the  liquid  components  of  the  blood,  so  as  to  be 
capable  of  passing  by  itself  into  the  condition  of  an  organized  tissue,  it  must  be 
the  one  most  readily  appropriated  by  the  various  parts  of  the  solid  fabric,  as  the 
material  for  their  growth  and  development. — Various  considerations  have  of  late 
been  adduced,  however,  which  tend  to  shake  this  belief.  It  has  been  shown  by 
Liebig,1  that  so  far  from  there  being  any  evidence  of  the  identity  of  the  Fibrin 
of  blood  and  the  substance  of  Muscle,  the  evidence  is  precisely  the  other  way. 
On  the  other  hand,  there  are  both  structural  and  chemical  indications,  that  Fibrin 
is  in  a  state  of  transition  rather  towards  the  Fibro-gelatinous  textures,  than 
towards  those  of  the  cellulo-albuminous  type }  for  the  fibrous  network  which  is 
formed  by  its  coagulation,  bears  a  greater  resemblance  to  the  white  fibrous  tissue, 
than  to  any  other  texture  of  the  body ;  whilst  the  points  in  which  the  chemical 
properties  of  fibrin  diifer  from  those  of  albumen,  are  such  as  manifest  a  relationship 
to  gelatin.  (See  PRINC.  OF  GEN.  PHYS.  Am.  Ed.)  We  seem  justified  in  regarding 
it,  then,  as  the  special  pabulum  of  those  connective  tissues,  whose  physical  offices 
in  the  economy  are  so  important,  whilst  their  vital  endowments  are  so  low ;  and 
as  serving,  by  its  own  formative  power,  for  the  generation  of  these  tissues, 
wherever  and  whenever  there  may  be  a  demand  for  them.  —  On  the  other  hand, 
there  is  a  complete  absence  of  evidence,  that  the  Fibrin  of  the  blood  serves  any 
special  purpose  in  the  nutrition  of  the  Cellulo-albuminous  tissues ;  and  there  are 
various  negative  indications,  that  their  generation  and  development  do  not  depend 
upon  its  presence.  For,  in  the  first  place,  there  is  evidence  that  a  fluid  destitute 
of  coagulating  power  may  serve  the  general  purposes  of  nutrition  j  this  being 
furnished,  not  merely  by  such  cases  as  that  just  alluded-to  (§  192),  in  which  the 
circulating  fluid  was  entirely  deficient  in  fibrin,  apparently  from  defective  elabo- 
ration ;  but  also  by  the  results  of  experiments  on  the  introduction  of  defibrinated 
blood  into  the  vessels  of  animals  which  had  been  reduced  to  syncope  by  the 
withdrawal  of  blood,  it  having  been  found  by  Dieffenbach 2  and  Bischoff,3  that 
this  operation  immediately  restored  the  heart's  action,  and,  with  it,  the  general 
train  of  vital  operations.  Further,  although  we  are  not  justified  in  positively 
affirming  that  the  fluid  which  transudes  the  walls  of  the  capillary  blood-vessels, 
for  the  nutrition  of  the  tissues  which  they  supply,  is  albuminous  rather  than 

*  "  Ann.  der  Chem.  und  Pharm."  band  Ixxii. 

»  "  Die  Transfusion  des  Blutes,"  Berlin,  1828.  3  "  Mullet's  Archiv.,"  1835. 


AND     ITS    RELATION    TO     THE     LIVING    ORGANISM.     217 

fibrinous,  yet  there  seems  a  strong  probability  that  such  is  the  case ;  all  non-in- 
flammatory exudations  being  albuminous,  unless  produced  by  an  excess  of  pres- 
sure ;  and  the  fluid  of  the  lymphatics,  which  is  probably  the  re-collected  surplus 
of  that  which  has  thus  escaped,  being  so  slightly  coagulable,  that  we  may  fairly 
regard  the  presence  of  fibrin  in  it  as  the  result  of  the  elaboration  which  it  has 
undergone  during  its  passage  through  the  absorbent  system.  Moreover,  the  for- 
mation of  the  Vegetable  cell  takes  place  at  the  expense  of  an  albuminous  fluid, 
there  being  no  element  in  the  juices  of  the  Plant  analogous  to  the  fibrin  of  the 
blood }  and  although  it  must  be  admitted  that  the  endowments  of  certain  parts 
of  Plants  are  so  peculiar,  as  to  detract  from  the  weight  of  any  such  argument, 
yet  when  it  is  considered  that  the  great  mass  of  the  Vegetable  fabric  grows  (like 
that  of  Animals)  at  the  expense  of  nutriment  already  prepared  for  it  (by  the 
agency  of  other  parts  of  the  fabric),  and  that  the  composition  of  the  Vegetable 
cell  is  essentially  the  same  as  that  of  the  Animal  cell,  the  fact  of  the  entire 
absence  of  any  substance  at  all  resembling  fibrin  in  the  vegetable  juices,  and  the 
corresponding  deficiency  of  fibro-gelatinous  tissues  in  their  solid  fabric,  may  be 
adduced  in  confirmation  of  the  views  here  advanced. 

209.  Even  if,  however,  we  thus  limit  the  value  of  Fibrin,  as  regards  the  or- 
dinary nutritive  processes,  to  the  maintenance  of  the  gelatinous  tissues,  we 
still  have  to  consider  it  as  a  most  important  component  of  the  blood,  and  as  al- 
together different,  in  its  relations  to  the  living  body,  from  those  products  of  dis- 
integration which  are  destined  to  excretion.1  For,  putting  aside  its  presumed 

1  The  extraordinary  hypothesis  has  been  put  forth  by  Dr.  Zimmerman,  and  espoused  by 
Mr.  Simon  and  some  other  Pathologists  in  this  country,  that  the  Fibrin  of  the  blood  is 
one  of  those  elements  of  the  circulating  fluid  "  which  have  arisen  in  it  from  its  own  decay, 
or  have  reverted  to  it  from  the  waste  of  the  tissues;"  instead  of  being  "that  ingredient 
of  the  blood,  which,  in  the  ascending  scale  of  development,  stands  next  for  appropriation 
into  the  living  textures  of  the  body,  and  which  represents  the  ripeness,  perfection,  and 
nutritiveness  of  the  blood."  (See  Mr.  Simon's  "Lectures  on  General  Pathology,"  p.  45, 
Am.  Ed).  —  This  doctrine  seems  to  the  Author  to  be  antithetically  opposed  to  the  whole 
physiological  history  of  Fibrin,  and  more  particularly  to  the  fact  of  its  gradual  develop- 
ment in  chyle  during  its  onward  progress  towards  the  sanguiferous  system;  whilst,  again, 
it  seems  to  be  directly  negatived  by  a  comparison  of  the  condition  of  fibrin  with  that  of 
the  known  products  of  the  disintegration  of  the  tissues,  such  as  urea,  or  creatine,  in  which 
we  see  a  marked  tendency  to  the  reproduction  of  purely  physical  modes  of  molecular  ag- 
gregation, to  the  exclusion  of  those  of  vitality.  These  last,  although  we  know  that  they 
must  be  continually  passing  through  the  blood,  are  eliminated  from  it  with  such  jealous 
cure,  that,  in  the  healthy  state,  they  scarcely  accumulate  in  sufficient  amount  to  be  detect- 
able by  analysis  (§  215) ;  it  is  scarcely  conceivable,  therefore,  that  Fibrin,  if  a  product  of 
retrograde  metamorphosis,  on  its  way  out  of  the  system,  should.be  normally  present  in 
the  blood  to  the  amount  of  2  or  3  parts  in  1000. — For  a  detailed  examination  of  the  objec- 
tions urged  by  Mr.  Simon  against  the  commonly-received  view,  the  reader  is  referred  to 
the  "  Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  vii.  p.  473. 

[Some  of  the  objections  to  the  commonly  received  doctrine  may  be  briefly  urged.  In  the 
first  place  it  is  scarcely  possible  to  believe  that  the  small  proportion  of  fibrine  which  exists 
in  healthy  blood,  can  supply  all  the  material  that  is  essential  to  repair  the  waste  that  is  so 
constantly  taking  place  in  every  tissue  of  the  body,  to  say  nothing  of  the  processes  of 
growth  that  are  so  actively  carried  on  in  early  life.  The  proportion  in  which  this  element 
exists,  is  not  more  than  about  one-fifth  per  cent,  or  less  than  five  drachms  in  the  whole 
amount  of  blood.  One  can  scarcely  fail  to  be  struck  with  the  insufficient  quantity,  and 
its  inability  to  supply  all  the  demands  made  upon  it,  if  it  be  the  chief  plastic  element. 

It  has  been  shown,  moreover,  that  the  fibrin  of  the  blood  is  undiminished,  nay,  even  in- 
creased, by  bleeding  and  starvation ;  its  highest  figure,  according  to  Andral  and  Gavarret 
(quoted  by  Mr.  John  Simon),  was  10-2  in  a  thousand  parts,  and  this  at  a  fourth  bleeding; 
and  Scherer  found  it  as  high  as  12-7  at  the  third  venesection  in  a  case  of  pneumonia. 
During  the  process  of  starvation,  when  it  would  be  expected  that  the  supply  of  the  plastic 
material  would  be  diminished,  Messrs.  Andral  and  Gavarret  found  the  maximum  of  fibrine 
to  be  5  parts  in  1000,  the  minimum  to  be  3,  the  mean  4 ;  and  Dr.  Franz  Simon  details 
the  result  of  an  analysis  of  the  blood  of  a  horse  who  had  been  deprived  of  food  four  days, 
in  whose  blood  the  fibrine  had  risen  from  five  to  nine.1  These  observations  are  corrobora 


1  "  F.  Simon's  Animal  Chem.",  p.  277,  Am.  Ed. 


218          OF  THE  BLOOD;   ITS  VITAL   PROPERTIES, 

importance  in  maintaining  that  physical  condition  of  the  blood  which  is  most 
favourable  to  its  free  movement  through  the  vessels,  and  to  its  due  retention 

tive  proofs  of  the  correctness  of  those  of  Nasse,  that  the  quantity  of  the  fibrine  is  increased 
during  prolonged  fasting. 

The  objection  of  the  author  to  the  increase  of  fibrine  during  fasting,  which  is  based 
upon  the  presence  of  inflammation  of  the  stomach,  as  observed  in  dogs  by  Andral,  is  more 
specious  than  real,  when  it  is  remembered  how  difficult  it  is  to  decide  upon  the  presence 
of  the  inflammatory  process  in  this  viscus  after  death. 

The  same  observers,  Messrs.  Andral  and  Gavarret,  have  stated  that  in  the  improvement 
of  the  breed  of  animals,  there  is  a  notable  diminution  of  the  quantity  of  fibrin,  and  an 
increase  in  the  red  corpuscles ;  and  Mr.  Simon  finds  a  further  indication  of  the  same  inverse 
ratio  between  the  fibrinousness  and  the  perfection  of  the  blood,  in  the  facts,  that  there  is 
little  or  no  fibrine  in  the  blood  of  the  foetus,  none  in  the  egg,  none  in  the  chyle,  and  less 
in  the  blood  of  the  carnivora  (who  feed  upon  it),  than  in  that  of  the  herbivora;  and  we 
have  the  authority  of  Nasse  and  Poggiale,  that  the  blood  of  new-born  infants  contains 
less  fibrine  than  that  of  adults ;  *  the  augmentation  in  the  amount  of  fibrine  taking  place 
most  rapidly  at  the  period  of  puberty.  The  blood  of  birds  also  contains  more  fibrine  than 
that  of  herbivora. 

In  addition  to  the  influence  of  defibrinated  blood,  quoted  by  the  author  from  Diffenbach 
and  Bischoff  (§  208),  may  be  mentioned  the  experiments  of  Dr.  Brown-Sequard  upon 
the  removal  of  cadaveric  rigidity  by  the  injection  of  defibrinated  blood.  In  two  cases  in 
which  the  experiments  were  performed  upon  criminals  executed  by  decapitation,  the  in- 
jection was  followed  by  a  return  of  muscular  irritability,  at  the  advanced  period  of 
thirteen  hours  after  death.  In  one  instance,  human  blood  was  used,  and  in  the  other, 
the  blood  of  a  dog ;  and  the  writer  has  been  informed  by  Dr.  Brown-Sequard,  that  the 
blood  which  was  injected,  deprived  of  fibrine  and  arterial  in  colour,  returned  by  the  vein 
with  the  venous  hue  and  coagulable.  The  same  experiments  were  performed  upon  lower 
animals,  and  with  a  like  result.  It  is  difficult  to  comprehend,  in  view  of  the  facts  stated 
above,  and  the  marked  increase  of  fibrine  in  anaemia,  in  phthisis,  and  in  acute  inflammation, 
after  days  of  starvation,  how  it  is  to  be  regarded  as  the  chief  plastic  material  of  the 
blood. 

In  regard  to  the  origin  of  fibrine,  the  opinion  is  maintained  by  some,  that  it  is  to  be 
traced  to  the  process  of  disintegration  and  waste  that  is  constantly  taking  place  in  the 
economy  ;  and  their  opinion  gains  support  in  the  fact  that  in  diseases  characterized  by 
rapidity  of  capillary  circulation  and  emaciation,  this  material  is  strikingly  increased ;  and 
in  the  fact  that  in  injection  of  defibrinated  blood,  the  fluid  returns  by  the  vein  possessing 
it  in  a  marked  degree.  That  it  does  not  arise  from  the  ingestion  of  food,  is  shown  by  the 
effect  produced  by  the  introduction  of  large  supplies  of  alimentary  materials,  which  is  ac- 
companied by  increase  of  the  solid  constituents  of  the  blood,  the  fibrine  remaining  un- 
changed. 

The  author  of  this  treatise  objects  to  the  view  above  stated,  on  the  ground  that  is  in  op- 
position to  the  gradual  development  of  fibrine  in  the  chyle  during  its  passage  towards  the 
Sanguiferous  system.  To  this  it  may  be  replied,  that  this  change  is  more  relative  than  posi- 
tive. The  lymphatics  of  the  intestinal  canal  are  in  two  layers,  one  superficial,  the  other 
deep-seated — one  communicating  with  the  other.  Those  which  are  traceable  to  the  villi, 
receive  the  products  of  chyliferous  absorption  (oily  particles),  and  are  off-sets  from  the 
deep-seated  layer.  In  their  progress  through  the  mesenteric  ganglion,  they  mingle  their 
contents  with  that  of  the  deep-seated  layer  which  carry  the  fibrine  and  albumen  of  in- 
testinal absorption,  and  in  this  way  the  increasing  presence  of  these  elements  in  the  chyle 
may  be  accounted  for ;  an  explanation  more  intelligible  than  the  violent  hypothesis  of  a 
change  of  oily  materials  into  nitrogenized  principles. 

The  opinion  of  Lehmann  upon  this  subject,  inclines  also  to  the  conclusion,  that  both 
the  albumen  and  fibrine  which  are  found  in  the  chyle,  are  the  result  of  additions  made  to 
it  either  from  the  blood  or  the  lymph ;  and  that  the  disappearance  of  the  fat  is  to  be  at- 
tributed to  the  saponification  of  that  substance  within  the  lacteals,  and  to  its  employment 
in  the  process  of  cell-formation.3  The  conversion  of  fat  into  albumen  is  quite  as  difficult 
of  comprehension  as  the  conversion  of  starch  into  albumen,  an  idea  which  the  author  him- 
self states  elsewhere  (p.  146,  note),  "would  now  be  universally  condemned  by  organic 
chemists." 

It  is  also  objected,  that  if  fibrine  be  a  retrograde  material,  why  is  it  endowed  with  the 
so-called  vital  properties  of  spontaneous  coagulation  ?  To  this  it  may  be  replied,  that  as 
fibrine  is  the  first  step  towards  retrogression,  and  has  just  escaped  from  living  tissues,  it 
may  readily  be  supposed  to  retain  a  certain  amount  of  the  properties  of  those  living  tis- 
sues, and  to  manifest  them  as  its  last  act  by  coagulating. 

1  "  Traits'  du  Chimie  Anatomique  et  Physiologique,"  par  C.  Robin  and  F.  Verdeil,  p.  203. 
J  "Physiological  Chem.,"  pp.  296—7. 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.    219 

within  their  walls  (§  195),  we  find  that  it  is  entirely  on  the  coagulating!:  powers  of 
the  blood,  that  the  cessation  of  haemorrhage  from  even  the  most  trifling  injuries 
is  dependent ;  that  the  limitation  of  purulent  effusions  by  the  consolidation  of 
the  surrounding  tissue,  and  the  safe  separation  of  gangrenous  parts,  can  only 
take  place  in  virtue  of  the  same  property;    and  that  the  adhesion  of  incised 
wounds,  still  more  the  filling-up  of  breaches  of  substance,  require  as  their  first 
condition,  that  either  the  blood,  or  matter  exuded  from  it,  should  be  able  to 
assume  the  state  of  fibrous  tissue.  —  The  results  of  deficiency  of  coagulating 
power  in  the  blood,  are  fearfully  seen  in  that  continued  and  uncontrollable  flow 
which  takes  place  in  Purpura,  the  blood  not  being  able  to  form  a  clot  sufficient 
to  fill-up  even  the  wound  made  by  the  scratch  of  a  pin ;  in  the  want  of  circum- 
scription of  collections  of  pus  within  abscesses,  allowing  its  infiltration  through 
tissues  that  were  previously  healthy,  and  thus  occasioning  a  wide-spread  destruc- 
tion of  organized  texture,  which  is  characteristic  of  certain  forms  of  inflamma- 
tion (this  result  being  usually  attributable  either  to  a  previously-unhealthy  con- 
dition of  the  system,  or  to  the  introduction  of  some  specific  poison  into  the 
blood) ;  in  the  absence  of  a  corresponding  limitation  between  the  living  and  the 
dead  parts  in  gangrene,  so  that  haemorrhage  takes  place  on  the  separation  of  the 
slough,  the  vessels  not  having  been  previously  obstructed  by  coagula ;  and  in  the 
entire  failure  of  any  effort,  either  by  simple  adhesion,  or  by  the  formation  of 
connective  tissue,  for  keeping-together  the  sides  of  open  wounds,  or  for  bringing 
dissevered  parts  again  into  connection  (See  CHAP,  viii.,  Sect.  2). — On  the  other 
hand,  we  see  the  consequences  of  excess  of  the  proportion  of  fibrin,  and  of  that 
increased  plasticity  (or  tendency  to  fibrillate)  which  usually  accompanies  its  aug- 
mentation, in  the  tendency  to  form  those  plastic  effusions  which  are  characteristic 
of  the  Inflammatory  state,  and  which,  if  poured-out  upon  serous  or  mucous  sur- 
faces, constitute  l false  membranes'  and  'adhesions/  or,  if  infiltrated  into  the 
substance  of  living  tissues,  occasion  their  consolidation.     This  increased  plas- 
ticity of  the  blood,  however,  may  frequently  be  regarded  in  the  light  of  an 

Or  the  opinion  of  Henl4  may  be  adopted,  that  the  natural  condition  of  fibrine  is  the  solid 
state,  and  that  is  in  held  in  solution  by  the  influence  of  living  tissues  with  which  it  is  in 
contact,  and  that  it  returns  to  the  solid  state  as  soon  as  those  influences  are  withdrawn. 

In  regard  to  the  destination  of  fibrine,  the  author  states  that  there  are  both  structural 
and  chemical  indications  that  fibrine  is  in  a  state  of  transition,  rather  towards  the  fibro- 
gelatinous  textures,  than  towards  those  of  a  cellulo-albuminous  type.  While  partially  grant- 
ing this,  there  seems  reason  also  to  suspect  that  a  portion  of  it  at  least  is  to  be  regarded 
as  excrementitious,  and  the  reason  for  this  belief  is  found  in  the  analysis  of  the  blood  of 
the  renal  vein,  as  compared  with  that  of  the  aorta;  the  former,  according  to  Dr.  Franz 
Simon,  containing  no  fibrine.1 

The  blood  of  the  renal  vein,  according  to  Bernard,  is  arterial  in  every  characteristic 
point,  except  that  it  is  deficient  in  fibrine,  a  circumstance  seeming  to  show  the  excretory 
nature  of  the  function  of  the  gland.  His  analyses,  as  well  as  those  of  Simon,  establish  the 
same  fact,  viz.,  the  removal  of  this  substance  in  the  passage  of  the  blood  through  the  organ. 

In  the  blood  of  the  hepatic  vein,  a  marked  diminution  in  the  quantity  of  fibrine  is  also 
shown  by  Simon's  analysis,  as  compared  with  that  of  the  portal  vein ;  both  the  liver  and 
the  kidney,  it  will  be  remembered,  acting  as  excreting  organs  in  the  economy. 

In  some  of  Simon's  analyses,  it  will  be  found  that  the  fibrine  is  in  larger  quantity  in 
venous  than  in  arterial  blood,  and  in  others  the  reverse.  In  the  bullock  and  the  sheep, 
the  fibrine  is  in  excess  in  arterial  blood ;  but  in  the  horse,  in  whom  muscular  exertion  is 
more  violent  and  prolonged,  the  fibrine  exceeds  in  venous  blood. 

Arterial  blood,  it  is  well  known,  rarely  presents  the  buffy  coat,  while  in  the  venous  blood 
it  is  frequently  met  with.  It  is  equally  well  known,  that  the  white  "heart-clot"  which 
is  so  often  found  in  the  right  heart,  is  never  found  in  the  left.3  From  some  observations 
of  Zimmerman's,  it  also  appears  that  the  blood  in  the  veins  remote  from  the  heart  is 
richer  in  fibrine,  than  that  in  the  veins  nearer  to  the  central  organ  of  circulation.3 

As  the  points  from  which  the  blood  was  taken  are  not  mentioned,  it  is  not  improbable 
that  the  variations  in  the  analyses  arose  from  the  circumstance  of  its  being  taken  in  some 
cases  from  non-secreting  surfaces,  as  from  muscles,  in  which  case  the  venous  blood  would 
probably  contain  most  fibrine,  and  in  others,  from  excreting  organs,  in  which  case  the  ar- 
terial would  possess  a  more  abundant  supply. — ED.] 

1  «  Chem.  of  Man."     3  «  Bernard's  Lectures  on  the  Blood."     3  Lehmann,  "  Phys.  Chem." 


220          OP  TUE   BLOOD;   ITS   VITAL   PROPERTIES, 

*  effort  of  Nature/  to  antagonize  the  evil  consequences  of  that  depression  or  posi- 
tive destruction  of  the  vitality  of  the  solid  tissues,  which  seems  to  form  an  essen- 
tial part  of  the  inflammatory  condition  j  and  thus  it  is,  that  whilst  the  central 
part  of  a  mass  of  tissue,  in  which  the  inflammation  has  been  most  intense,  suffers 
complete  death,  and  is  carried-away  in  the  suppurative  process,  the  peripheral 
part,  in  which  the  violence  of  the  inflammation  has  been  less,  becomes  infiltrated 
with  plastic  matter  poured-out  from  the  blood,  and  forms  the  solid  and  impel 
meable  wall  of  the  abscess.  (See  CHAP,  vin.,  Sect.  3). 

210.  Turning  now  to  the  Corpuscles  of  the  Blood,  we  have  to  inquire  into 
their  special  functions,  and  into  the  nature  of  their  participation  in  the  vital 
operations  of  the  system  at  large.     Here,  also,  we  are  obliged  to  rely  upon  evi- 
dence of  a  far  less  satisfactory  nature  than  could  be  desired ;  and  at  whatever 
conclusions  we  may  arrive,  we  must  hold  them  as  probable  only,  and  as  liable  to 
be  modified  by  further  inquiry. — In  the  first  place,  upon  looking  to  the  chemical 
constitution  of  the  Red  corpuscles,  we  find  that  it  possesses  a  remarkable  cor- 
respondence with  that  of  Muscle,  in  the  proportion  of  potash-salts  which  they 
both  contain  (in  this  respect  differing  in  a  very  marked  manner  from  the  liquor 
sanguinis) ;  whilst  their  globulin  is  more  nearly  related  to  muscle-substance,  than 
is  the  fibrin  of  the  blood  with  which  the  latter  has  been  usually  identified.     So, 
again,  it  exhibits  a  like  correspondence  with  that  of  the  Nerve-substance,  in  the 
quantity  of  phosphorizetl  fat  which  both  include  (§  160).     Further,  the  peculiar 
colour  which  the  vesicular  nervous  matter  and  the  muscular  substance  of  warm- 
blooded animals  exhibit,  although  doubtless  attributable  in  part  to  the  actual 
presence  of  red  blood  in  these  tissues,  yet  partly  depends  upon  a  pigmentary 
matter  in  their  own  substance,  which  seems  closely  to  resemble  haematin.     Thus, 
then,  from  the  relative  composition  of  the  Red  corpuscles  and  of  the  Muscular 
and  Nervous  tissues,  there  appears  to  be  much  reason  for  regarding  the  former 
as  destined  to  prepare  or  elaborate  materials,  which  are  to  be  subservient  to  the 
nutrition  of  the  latter.     Again,  we  have  seen  that  although  the  difference  in  the 
colour  of  the  red  corpuscles  of  arterial  and  venous  blood,  cannot  now  be  con- 
sidered (as  it  formerly  was)  to  be  an  indication  of  chemical  change  in  their  con- 
tents —  effected,  on  the  one  hand,  by  the  agency  of  carbonic  acid,  and,  on  the 
other,  by  that  of  oxygen,  —  yet  there  still  appears  reason  to  regard  these  cor- 
puscles as  having  more  power  of  absorbing  those  gases,  than  is  possessed  by  any 
other  constituent  of  the  blood  (§  160).     Hence  we  may  look  upon  them  as 
specially  subservient  to  the  vital  activity  of  the  Nervo-Muscular  apparatus ;  since 
it  is  one  of  the  most  important  conditions  of  that  activity,  that  these  tissues  shall 
be  supplied  with  duly  oxygenated  blood,  and  that  the  carbonic  acid  which  is  one 
of  the  products  of  their  disintegration,  shall  be  conveyed-away.     And  this  view 
is  in  complete  harmony  with  the  fact,  that  the  proportion  of  Red  corpuscles  in 
the  blood  bears  a  close  relation  to  the  amount  of  Respiratory  power  (as  shown  in 
the  quantity  of  carbonic  acid  set-free,  and  in  the  amount  of  heat  generated)  in 
different  classes  of  Vertebrata ;  loth  being  greatest  in  Birds,  nearly  as  great  in 
Mammals,  very  low  in  most  Reptiles,  and  varying  considerably  among  Fishes.1 
Again,  we  observe  that  among  Carnivorous  Mammalia,  the  proportion  of  red  cor- 
puscles is  considerably  greater  than  it  is  among  the  Herbivorous  tribes,  whose 
nervo-muscular  energy  is  (upon  the  whole)  so  greatly  inferior;  and  it  is  in  the 

1  Among  Invertebrated  animals,  as  a  general  rule,  the  degree  of  nervo-muscular  energy 
that  can  be  put-forth,  the  quantity  of  carbonic  acid  produced  in  respiration,  and  the  amount 
of  heat  generated  in  the  body,  are  alike  at  a  low  standard ;  and  the  fluid  constituents  of 
the  blood,  with  the  colourless  corpuscles  that  float  in  it,  would  seem  to  convey  oxygen  to 
the  tissues,  and  carbonic  acid  to  the  respiratory  organs,  with  sufficient  facility.  In  In- 
sects, however,  the  case  is  different ;  their  nervo-muscular  activity,  capacity  of  respira- 
tion, and  heat-producing  power  being  all  extraordinarily  high.  Their  want  of  red  cor- 
puscles would  here  seem  to  be  compensated,  so  far  as  the  respiratory  process  is  concerned, 
by  the  introduction  of  air,  through  the  tracheal  apparatus,  into  the  tissues  themselves. 
(See  "  Princ.  of  Comp.  Phys.,"  Chap.  vi.  sect.  3,  and  Chifr  x.  sect.  3.J 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.     221 

condition  of  greatest  animal  vigour,  in  the  Human  system,  that  we  find  their 
amount  the  greatest,  whilst  the  reduction  of  that  vigour  by  chronic  disease  of 
any  description,  seems  invariably  attended  with  a  more  marked  diminution  in 
this  constituent  of  the  blood  than  in  any  other.  And  in  those  Ansemic  states 
of  the  system,  in  which  the  proportion  of  red  corpuscles  is  reduced  to  an  ex- 
tremely low  point  (§  190),  we.  invariably  find  that  the  animal  powers  are  cor- 
respondingly depressed;  the  capacity  for  sustained  exertion,  either  of  the  mental 
faculties,  or  of  the  motor  apparatus,  being  almost  destroyed,  although  both  the 
nervous  and  muscular  systems  are  very  easily  excited  to  feeble  action. — However 
difficult  it  may  seem  to  explain,  on  this  view,  the  persistence  of  any  degree  of 
nervo-muscular  power,  in  such  cases  as  that  already  referred  to,  in  which  the  Red 
corpuscles  appeared  to  be  entirely  deficient  (§  192),  the  same  difficulty  attends 
any  attempt  to  assign  a  use  for  them,  which  shall  be  in  accordance  with  their 
well-marked  importance  as  constituents  of  the  Blood.  And  we  may  suppose 
that,  in  such  cases,  the  Colourless  corpuscles,  although  discharging  the  duty  less 
perfectly,  might  perform  it  to  a  certain  extent,  as  they  seem  to  do  among  the 
Invertebrata. 

211.  The  difficulty  of  precisely  determining  the  functions  of  the  Red  cor- 
puscles, is  even  surpassed  by  that  of  assigning  the  probable  duty  of  the  Colour- 
less. The  considerations  already  adduced  appear  to  show,  that  the  Colourless 
corpuscles  are  to  be  considered  as  cells  of  a  lower  grade  than  the  Red ;  since 
they  represent  them  among  Invertebrated  animals,  and  also  in  the  incipient  blood 
of  Vertebrata ;  and  also,  because  cells  resembling  the  former  (if  not  the  very 
same)  pass-on  to  develope  themselves  into  the  latter  (§  169).  Still  we  find  that 
this  final  change  does  not  occur  among  the  Invertebrata;  and  it  is  obvious,  there- 
fore, that  even  in  their  colourless  state,  the  corpuscles  have  a  function  to  dis- 
charge in  the  vital  economy.  Little  light  has  yet  been  thrown  upon  this  subject, 
by  inquiry  into  the  Chemical  composition  of  the  blood-corpuscles  of  the  lower 
animals;  and  no  means  have  yet  been  devised  for  obtaining  the  colourless  cor- 
puscles of  the  higher  in  a  separate  state,  for  the  purpose  of  determining  this. 
A  minute-sample  of  the  blood-corpuscles  of  a  Crab,  however,  examined  by  Prof. 
Graham,  has  been  found  by  him  to  contain  "  a  sensible  quantity  of  iron,  the  pro- 
portion being  perhaps  as  large  as  in  red  corpuscles."  l  Thus,  then,  we  have  evi- 
dence that  the  difference  of  hue  between  the  two  sets  of  Corpuscles,  does  not 
involve  any  considerable  difference  in  the  proportion  of  one  of  the  most  charac- 
teristic elements  of  the  Red;  and  if  it  be  admitted  that  they  are  both  to  be 
looked-upon  as  having  the  same  origin,  and  as  differing  only  in  their  stage  of 
development,  it  is  manifest  that  no  other  difference  can  be  fairly  expected  to  exist 
in  their  contents,  than  that  which  is  marked  by  the  formation  of  the  colouring- 
matter,  as  the  final  effort  of  their  transforming  power.  This  product,  as  we  have 
seen  (§  160),  constitutes  but  about  one-twentieth  of  the  whole  contents  of  the 
Red  corpuscles.  —  The  following  observation  by  Mr.  Newport  seems  to  indicate, 
that  the  corpuscles  of  the  blood  of  Insects  (some  of  them  in  the  condition  of 
( granule-cells/  others  in  that  of  *  nucleated  colourless  cells/  §  169),  have  an 
important  function  to  perform  in  the  elaboration  of  nutrient  material.  The  '  oat- 
shaped'  corpuscles  (the  '  granule-cells'  of  Mr.  Wharton  Jones)  are  found,  in  the 
Larva,  to  be  most  numerous  at  the  period  immediately  preceding  each  change  of 
skin ;  at  which  time  the  blood  is  extremely  coagulable,  and  evidently  possesses 
the  greatest  formative  power.  The  smallest  number  are  met-with  soon  after  the 
change  of  skin ;  when  the  nutrient  matter  of  the  blood  has  been  exhausted  in 
the  production  of  new  epidermic  tissue.  In  the  Pupa  state,  the  greatest  number 
are  found  at  about  the  third  or  fourth  day  subsequent  to  the  change;  when  pre- 
parations appear  to  be  most  actively  going-on,  for  the  development  of  the  new 
parts  that  are  to  appear  in  the  perfect  Insect.  After  this,  there  is  a  gradual 

1  "Philosophical  Transactions,"  1846,  p.  105. 


222         OF  THE  BLOOD;  ITS  VITAL   PROPERTIES, 

diminution ;  the  plastic  element  being  progressively  withdrawn  by  the  formative 
processes;  until,  in  the  perfect  Insect,  very  few  remain.  When  the  wings  are 
being  expanded,  however,  and  are  still  soft,  a  few  oat-shaped  corpuscles  circulate 
through  their  vessels ;  but  as  the  wings  become  consolidated,  these  corpuscles 
appear  to  be  arrested  and  to  break-down  in  the  circulating  passages;  supplying, 
as  Mr.  N.  thinks,  the  nutrient  material  for  the  completion  of  these  structures, 
which  subsequently  undergo  no  change.1  The  blood  also  contains  nucleated 
cells,  the  proportion  of  which  seems  to  increase  in  the  Imago  state,  whilst  that 
of  the  '  granule-cells'  diminishes. 

212.  That  condition  of  the  corpuscular  element  of  the  blood  which  is 
normal  in  the  Insect,  must  be  considered  as  decidedly  abnormal  in  the  Verte- 
brated  animal,  in  which  the  circulating  fluid  goes-on  to  a  higher  phase  of  devel- 
opment ;  and  the  excess  of  Colourless  corpuscles  in  the  latter  seems  always  to  be 
associated  (save  in  the  early  part  of  life)  with  an  imperfect  performance  of  their 
nutritive  operations.  Thus,  according  to  the  observations  of  Mr.  Paget,  they  are 
especially  abundant  in  the  blood  of  frogs  that  are  young,  sickly,  or  ill-fed ;  and 
whilst  in  the  first  of  these  cases,  their  large  number  seems  to  depend  upon  rapid 
increase,  so  that  the  new  red  corpuscles  may  be  generated  in  adaptation  to  quick 
growth,  in  the  two  latter  their  accumulation  seems  rather  to  be  attributable  to  a 
retardation  of  development  through  disease  or  defective  nutriment,  so  that, 
although  their  production  is  not  hindered,  their  normal  metamorphosis  does  not 
take  place.  So,  as  regards  the  human  subject,  Mr.  Paget2  confirms  the  statement 
of  Mr.  Wharton  Jones  and  Prof.  J.  H.  Bennett,  that  the  increased  proportion  of 
Colourless  corpuscles,  which  has  been  regarded  by  some  observers  (especially  by 
Mr.  Addison  and  Dr.  C.  J.  B.  Williams)  as  characteristic  of  inflammatory  blood, 
and  particularly  of  that  which  is  drawn  from  an  inflamed  part,  is  far  from  being 
a  constant  phenomenon ;  being  most  frequent  when  the  subjects  of  the  disease 
are  persons  in  weak  health,  or  of  the  tuberculous  diathesis,  as  has  been  remarked 
also  by  Nasse  and  Popp.  And  Mr.  Paget  has  furnished  a  remarkable  confirma- 
tion of  this  view,  in  the  observation,  that  the  inflammatory  exudations  produced 
in  different  individuals,  by  the  application  of  the  same  stimulus  on  the  same 
tissue  (e.  g.  by  the  action  of  a  blister  on  the  skin)  are  found  to  present  a  pre- 
dominance of  the  fibrinous  or  of  the  corpuscular  element,  according  to  the  general 
condition  of  the  patient.  "  The  highest  health  is  marked  by  an  exudation  con- 
taining the  most  perfect  and  unmixed  fibrin ;  the  lowest  by  the  formation  of  the 
most  abundant  corpuscles,  and  their  nearest  approach,  even  in  their  early  state, 
to  the  characters  of  pus-cells.  The  degrees  of  deviation  from  general  health  are 
marked,  either  by  increasing  abundance  of  the  corpuscles,  their  gradual  predom- 
inance over  the  fibrin,  and  their  gradual  approach  to  the  character  of  pus-cells; 
or  else  by  the  gradual  deterioration  of  the  fibrin,  which,  from  being  tough,  elastic, 
uniform,  and  of  filamentous  appearance  or  filamentous  structure,  becomes  less 
and  less  filamentous,  softer,  more  paste-like,  turbid,  nebulous,  dotted,  and  mingled 
with  minute  oil-molecules."  "  After  some  practice/'  adds  Mr.  Paget t(  one  might 
form  a  fair  opinion  of  the  degree  in  which  a  patient  was  cachectic,  and  of  the 
degree  in  which  an  inflammation  in  him  would  tend  to  the  adhesive  or  to  the  sup- 
purative  character,  by  the  microscopic  appearance  of  these  exudations." 3  — From 
such  evidence  we  seem  forced  to  the  conculusion,  that,  whether  or  not  the  Colour- 
less corpuscles  are  to  be  regarded  in  any  other  light  than  as  blood-cells  not  yet  fully 
developed,  their  multiplication  is  not  (as  was  once  maintained  by  the  Author  and 
others)  the  source  of  increase  in  the  fibrinous  constituent  of  the  liquor  sanguinis.4 

1  "  Philosophical  Magazine,"  May,  1845. 

1  'Lectures  on  Inflammation,'  in  "Medical  Gazette,"  1850,  vol.  xlv.  pp.  972,  973;  and 
"  Surgical  Pathology'"  p.  206,  Am.  Ed. 

1  "Med.  Gazette,"  1850,  vol.  xlv.  p.  1015 ;  and  "  Surgical  Pathology,"  p.  220,  Am.  Ed. 

4  The  Author  cannot  help  still  suspecting,  however,  that  the  Colourless  corpuscles  are  not 
to  be  regarded  merely  as  red  blood-cells  in  their  earlier  phase  of  development ;  but  that 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.     223 

Whether  the  arrest  of  development  of  these  corpuscles,  in  the  abnormal  condi- 
tions just  referred-to,  is  to  be  attributed  to  an  original  want  of  capacity  in  their 
germs,  or  to  some  agency  which  subsequently  depresses  their  vital  power,  or  to  " 
the  want  of  some  material  which  they  require  for  the  purpose,  can  scarcely  at 
present  be  decided ;  and  it  may  be  doubted  whether  any  one  of  these  determining 
causes  is  in  action  in  every  case,  or  whether  each  of  them  may  not  occasionally 
operate,  either  singly  or  in  combination. 

213.  Turning  now  to  those  constituents  of  the  Blood  which  show  no  indica- 
tions of  possessing  vitality,  we  have  first  to  speak  of  its  Albumen.  The  relations 
which  this  substance  bears  to  the  living  body  are  of  the  most  important  and 
fundamental  character;  since,  as  elsewhere  shown  (PRINC.  OF  GEN.  PHYS),  it  is 
the  original  pabulum  at  the  expense  of  which  all  the  solid  tissues  are  generated, 
whilst  it  also  affords  the  material  for  the  production  of  the  fibrin,  the  globulin, 
and  the  hgernatin  of  the  blood  itself.  It  appears,  however,  to  be  itself  entirely 
destitute  of  formative  capacity ;  for  in  no  exudation  which  is  purely  serous,  do 
we  ever  trace  the  slighest  indication  of  organization ;  and  its  conversion  into  the 
various  kinds  of  tissue,  therefore,  must  be  entirely  due  to  their  own  power  of 
appropriating  and  transforming  it.1  The  great  function  of  the  Albumen  of  the 
blood,  then,  is  to  supply  the  material  for  these  various  transformations ;  and  we 
accordingly  find  that  whatever  other  changes  the  fluid  may  undergo,  whether  it 
loses  its  fibrin  or  its  red  corpuscles,  or  both,  albumen  is  still  present  in  abundance. 
[M.  Bernard  has  recently  shown  that  the  albumen  contained  in  the  blood  exerts 
an  energetic  influence  upon  that  fluid,  by  enabling  it  to  retain  many  substances 
in  solution  which  are  ordinarily  precipitated  in  an  alkaline  fluid.  Sulphate  of 
copper,  for  example,  which  is  precipitated  by  Liquor  Potassae,  circulates  freely 
in  the  blood  in  a  state  of  solution,  retained  in  this  condition,  as  he  believes,  by 
the  presence  of  albumen.  If  the  albumen  be  withdrawn  from  the  blood  by  any 
organ,  either  for  its  nutrition,  or  to  furnish  materials  for  secretion,  the  metal 
will  be  deposited  in  that  organ  ]  thus  antimony  is  deposited  in  the  liver,  and 
mercury  and  arsenic  in  other  organs. 

Albumen  also  alters  the  chemical  relations  of  certain  substances  to  each  other, 
or  so  masks  them  that  they  fail  to  be  recognized.  Thus,  lactate  of  iron,  mingled 
with  blood  forms  a  combination  with  albumen,  so  that  the  addition  of  Cyanide  of 
Potassium  fails  to  produce  the  Prussian  blue.  If,  now,  an  energetic  acid  be 

they  have  some  special  connection  with  the  elaboration  of  the  plastic  constituents  of  the 
blood.  Warned,  however,  by  previous  experience,  of  the  danger  of  building  conclusions 
upon  observations  of  a  limited  and  imperfect  character,  he  refrains  at  present  from  offering 
any  hypothesis  as  to  the  nature  of  that  relation, — merely  suggesting,  that  it  is  far  from 
certain  that  all  the  bodies  which  pass  under  the  designation  of  '  white '  or  '  colourless 
corpuscles'  are  of  the  same  kind,  as  is  shown  by  the  fact,  that  cells  are  formed  in  exuda- 
tions, which  cannot  be  distinguished  from  the  colourless  cells  of  the  blood,  and  which  yet 
can  scarcely  be  supposed  to  be  rudimental  red-corpuscles ;  and  that  if  some  of  the  '  colour- 
less corpuscles '  of  the  blood  be  looked-upon  as  instrumental  in  elaborating  its  plastic  com- 
ponents, whilst  others  are  on  the  march  of  development  into  red  corpuscles,  it  seems  very 
probable  that  the  same  depressing  influence  which  checks  the  latter  process  should  also 
interfere  with  the  former,  and  that  thus  an  accumulation  of  colourless  corpuscles  in 
cachectic  subjects  may  coincide  with  a  diminution  in  the  red,  and  at  the  same  time  with 
an  imperfect  elaboration  of  the  fibrin  of  their  blood. 

1  Those  who  maintain  that  Fibrin  is  the  only  organizable  constituent  of  the  blood,  and 
that  it  is  the  immediate  source  of  the  nutrition  of  the  tissues  generally,  consider  that 
Albumen  cannot  be  appropriated  by  the  tissues,  without  first  pacing  through  the  con- 
dition of  fibrin.  This  doctrine,  formerly  contended-for  by  the  Author,  he  now  abandons 
as  inconsistent  with  much  that  we  know  of  the  history  of  Fibrin  and  of  its  destination  in 
the  body  (§  208) ;  and  he  would  rest  upon  the  simple  fact, — that  the  first  development  of 
the  embryonic  mass,  by  the  multiplication  of  its  component  cells,  takes  place  in  a  fluid  in 
which  nothing  analogous  to  fibrin  can  be  discovered, — as  showing  that  cells  are  able  to 
draw  their  support  directly  from  an  albuminous  pabulum ;  whilst  it  is  only  when  the  gela- 
tinous tissues  begin  to  be  formed  in  the  embryo,  that  we  find  its  blood  to  become  spon- 
taneously coagulable. 


224          OP  THE   BLOOD;   ITS  VITAL  PROPERTIES, 

added  which  will  destroy  the  albumen,  the  colour  will  at  once  be  formed.  Or  if 
the  materials  be  separated  from  the  blood  by  any  secreting  organ,  without  the 
albumen,  the  characteristic  colour  will  be  found  in  the  organ  by  which  it  is 
thrown-off  (§  94)  '.— ED.] 

Its  ultimate  source  is  to  be  found  in  the  food ;  but  the  serous  liquid  which  per- 
colates the  tissues  of  the  body  may  be  regarded  as  a  reserve-store,  to  be  drawn-upon 
in  casey  of  need,  furnishing  albumen  to  the  blood  when  it  might  otherwise  be 
deficient  ;  and  thus  perhaps  it  is,  that  abstinence  or  repeated  losses  of  blood  do 
not  produce  the  degree  of  depression  in  the  proportion  of  albumen  which  might 
be  expected  from  the  very  marked  reduction  they  effect  in  that  of  the  corpuscles.2 
When  an  excess  of  Albuminous  matter  is  ingested  as  food,  the  injurious  effects 
which  might  follow  the  too  great  augmentation  of  this  constituent  of  the  Blood, 
appear  to  be  averted  by  the  readiness  with  which  it  undergoes  retrograde  as  well 
as  progressive  metamorphosis;  for,  if  not  speedily  subjected  to  the  latter  change, 
it  appears  to  be  affected  by  decomposing  agencies,  and  to  be  eliminated  from  the 
system  by  the  excretory  apparatus,  under  the  form  of  urinary  and  biliary  matter. 
(See  CHAP.  IX.)  Although  Albumen  seems  to  furnish  certain  constituents  of 
secretions  which  are  applied  to  special  purposes  within  the  body,  yet  its  passage 
as  such  into  the  excretions  must  be  looked-upon  as  quite  abnormal,  and  as  (so  to 
speak)  a  mere  waste  of  nutrient  material. 

214.  The  Fatty  matters  of  the  Blood  are  obviously  destined  to  furnish  the  con- 
tents of  the  Adipose  and  Nervous  vesicles ;  whilst  their  presence  seems  also  to  be 
required  in  the  early  stages  of  the  production  of  Cells  generally.  One  of  the 
principal  sources  of  their  expenditure,  however,  is  that  combustive  process  by 
which  the  heat  of  the  body  is  maintained ;  and  the  amount  deposited  in  the 
tissues  as  fat,  may  be  looked-upon  as  the  surplus  of  the  quantity  ingested,  that 
is  not  thus  consumed.  The  quantity  of  fatty  matter  in  the  blood  is  liable  to 
sudden  augmentation,  from  the  introduction  of  a  large  quantity  furnished  at 
once  by  the  alimentary  material ;  and  this  excess  will  continue  until  the  surplus 
has  been  eliminated,  either  by  the  combustive,  the  nutritive,  or  the  excretory 
operations.  These  last  do  not  ordinarily  remove  the  saponifiable  fats  from  the 
body;  for  although  the  mammary  secretion  in  the  female  draws-off  from  her 
blood  a  large  quantity  of  fatty  matter,  this  is  destined,  not  for  its  purification, 
but  for  the  nutrition  of  her  offspring;  and  cholesterin  appears  to  be  the  only 
fatty  substance,  which  is  normally  excreted  for  the  purpose  of  being  removed 
from  the  body.  Fatty  matters  are  often  detectable  in  small  quantities  in  the 
healthy  faeces,  where,  however,  their  presence  may  be  attributed  to  the  non-ab- 
sorption of  a  portion  of  those  which  the  food  had  included ;  and  this  want  of 
absorption  seems  specially  to  occur  in  cases  in  which  the  action  of  the  Pancreas 
or  of  the  Liver  is  disturbed  by  disease  of  one  or  both  of  those  organs.3  But 
they  are  sometimes  discharged  in  such  large  quantities,  that  it  is  scarcely  possible 
thus  to  account  for  their  presence ;  and  it  would  seem  that  they  must  have  been 
poured  into  the  alimentary  canal,  either  by  the  liver  or  by  some  other  excreting 
organ  which  must  have  drawn  them  off  from  the  blood.  It  does  not  seem  an 
improbable  surmise,  that,  in  such  cases,  there  may  be  an  extraordinary  tendency 
to  the  metamorphosis  of  albuminous  and  other  azotized  matters  (whether  fur- 
nished by  the  tissues  or  by  the  food)  into  fat ;  and  that  the  excretion  of  this 
substance  does  in  effect  tend  to  keep-down  their  proportion  in  the  blood.  Their 

1  "Bernard  and  Robin  on  the  Blood." 

a  It  is  to  be  remembered,  however,  that  the  whole  mass  of  the  blood  (liquid  as  well  as 
solid)  is  probably  reduced  under  these  circumstances ;  it  having  been  found  by  the  experi- 
ments of  Chossat  ("  Recherches  Experimentales  sur  1'Inanition"),  that  when  animals  were 
killed  by  starvation,  the  blood  lost  no  less  than  75  per  cent,  of  its  weight,  whilst  the 
average  loss  of  the  whole  body  was  40  per  cent. 

3  See  Dr.  Bright's  Memoir  on  «  Disease  of  the  Pancreas  and  Duodenum,'  in  "  Medico- 
Chirurg.  Trans."  vol.  xviii. ;  and  the  Art.  '  Pancreatic  Disease  and  Fatty  Discharges,'  in 
"Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  xii.  p.  154. 


AND   ITS    RELATION   TO   THE   LIVING   ORGANISM.          225 

occasional  extraordinary  accumulation  in  the  circulating  fluid  (§  192)  tends  to 
confirm  this  view ;  for  it  appears  scarcely  possible  that  such  an  enormous  pro- 
portion of  fat  could  have  been  derived  from  the  food,  either  in  the  condition  of 
fat,  or  in  that  of  a  saccharine  compound  capable  of  being  converted  into  it. 

215.  All  the  other  Organic  compounds  which  have  been  distinctly  recognized 
in  the  blood,  or  of  whose  presence  in  the  circulating  current  we  have  inferential 
evidence,  — sugar,  lactic  acid,  urea,  uric  acid,  hippuric  acid,  creatine,  creatinine, 
the  volatile  fatty  acids,  and  the  odorous  substances, — are  to  be  considered,  not  as 
in  any  way  subservient  to  those  constructive  changes  in  which  Nutrition  properly 
consists,  but  as  products  of  the  retrograde  metamorphosis,  either  of  the  alimen- 
tary materials,  or  of  the  tissues  themselves ;  and  as  on  their  way  to  be  elimi- 
nated from  the  blood,  either  by  the  respiratory  organs,  or  by  some  other  part  of 
the  Excretory  apparatus.     And  the  more  perfect  the  balance  between  the  action 
of  this  apparatus,  and  the  operations  whereby  these  compounds  are  generated, 
the  less  will  be  the  proportion  in  which  they  present  themselves  in  the  blood, 
and  the  greater  will  be  the  difficulty  in  detecting  them  there. 

216.  The  uses  of  the  various  Inorganic  compounds,  which,  as  being  uniformly 
present  in  the  Blood,  must  be  considered  among  its  integral  constituents,  are  not 
as  yet  by  any  means  positively  known ;  yet  great  advances  have  been  recently 
made  towards  this  knowledge ;  arid  it  may  be  pretty  certainly  affirmed,  that  the 
presence  of  some  of  them  has  reference  to  the  peculiar  functions  and  conditions 
of  the  blood  itself,  whilst  others  are  chiefly  destined  for  appropriation  by  the 
tissues  to  whose  growth  it  ministers.     The  former  seems  to  be  especially  the  case 
with  the  Alkaline  salts ;  of  which  the  phosphate  and  carbonate  of  soda  would 
seem  to  have  it  for  their  chief  purpose,  to  maintain  the  alkalirffty  of  the  blood, 
on  which  depend  not  merely  the  liquidity  of  its  albumen,  but  the  facility  of  its 
passage  through   the  capillaries,  and   the  readiness  with  which  its  combustive 
materials  are   oxidized ;  whilst   they  also  increase  the  absorptive  power  of  the 
serum  for  gases.     So  the  presence  of  chloride  of  sodium  is  needed  for  the  conser- 
vation of  the  organic  components  of  the  blood  in  their  normal  condition,  and  it 
also  seems  to  be  essential  to  the  performance  of  many  of  the  metamorphic  and 
histogenetic  operations  to  which  these  substances  are  subjected  in  the  economy; 
this  salt,  moreover,  is  itself  required  as  a  component,  not  only  of  the  solid  tissues 
generally,  but  also  of  all  the  secreted  fluids.     The  salts  of  potash  appear  to  be 
specially  required  for  the  nutrition  of  the  muscular  tissue ;  but  they  probably 
exert  the  same  general  influence  with  those  of  soda.     The   presence   of  the 
Earthy  salts,  on  the  other  hand,  would  seem  to  have  reference  almost  exclusively 
to  the  composition  of  the  tissues,  into  which  some  of  them  enter  very  largely. 
The  phosphate  of  lime  in  particular  must  be  regarded  almost  in  the  light  of  a 
histogenetic  substance,  so  constantly  does  it  seem  to  be  present  in  newly-forming 
tissues;  whilst  it  is  also  in  great  demand  as  the  principal  consolidating  material 
of  bone  and  tooth.     Whether  the  carbonate  of  lime^  the  phosphate  of  magnesia, 
the  fluoride  of  calcium,  and  the  silica  of  the  blood,  are  of  any  other  use  in  it 
than  to  supply  consolidating  materials  for  the  tissues,  there  is  at  present  no  evi- 
dence whatever.     Iron,  like  the  alkaline  salts,  is  an  essential  constituent  of  the 
blood  itself,  forming  a  very  large  per-centage  of  the  hsematin  of  its  red  corpus- 
cles ;  and  it  is  supplied  by  the  blood  to  various  tissues,  especially  the  muscles 
and  the  hair,  of  which  also  it  may  be  considered  an  essential  component.  — The 
normal  proportions  of  all  these  substances  appear  to  be  chiefly  maintained  by 
means  of  the  excretory  apparatus,  which  filters-off  (so  to  speak)  any  surplus  ;  it 
being  through  the  Urinary  organs  that  they  are  chiefly  eliminated.     And  it  is 
by  them,  too,  that  the  normal  proportion  of  Water  in  the  blood  is  chiefly  main- 
tained ;  the  Malpighian  apparatus  of  the  kidneys  apparently  acting  as  a  kind  of 
safety-valve,  through  which  any  surplus  that  remains  after  the  cutaneous,  pul- 
monary,  and  intestinal  exhalants   have  performed  their  appropriate  duties,  is 
allowed  to  make  its  escape. 

15 


226          OF  THE   BLOOD;   ITS  VITAL   PROPERTIES, 

217.  It  is  not  alone  by  the  proper  Excretory  apparatus,  however,  that  the  fit- 
ness of  the  Blood  for  circulation  through  the  body  is  maintained.  Every  tissue 
draws  from  the  circulating  fluid  some  particular  material,  or  combination  of 
materials,  which  constitutes  its  own  special  pabulum  ;  and  as  the  '  pabulum '  of 
each  tissue  is  different,  it  follows  that  the  normal  composition  of  the  blood  can 
only  be  preserved,  without  waste  of  substance,  by  the  existence  of  such  a  balance 
between  the  appropriate  action  of  the  several  parts,  as  shall  cause  a  certain  equi- 
valent of  blood  to  supply,  without  deficiency  or  surplus,  the  materials  which  they 
collectively  require.  Such  a  balance  is,  in  fact,  ordinarily  preserved ;  and  its 
maintenance  is  one  of  the  most  marvellous  of  those  exemplifications  of  Design, 
which  the  vital  economy  of  the  body  presents  in  no  less  a  degree  than  its  orga- 
nized structure ;  an  exemplification,  however,  which  becomes  yet  more  marvel- 
lous, when  it  is  shown  that  not  only  every  kind  of  tissue,  but  every  spot  of 
every  organ,  has  its  own  special  'pabulum;'  drawing  something  from  the  blood, 
which  is  different  from  that  appropriated  by  every  other  part  of  the  body,  save 
the  corresponding  spot  on  the  opposite  side.  This  position  seems  fully  esta- 
blished by  the  researches  of  Dr.  W.  Budd  and  of  Mr.  Paget  on  'Symmetrical 
Diseases ' !  the  phenomena  of  which  are  full  of  interest,  as  illustrating  the  ordi- 
nary operations  of  Nutrition.  Excluding  the  cases  of  congenital  symmetrical 
defects,  and  a  few  which  seem  to  depend  on  morbid  influence  of  the  nervous 
system,  it  may  be  stated  as  a  general  fact,  that  all  symmetrical  diseases  depend 
on  the  presence  of  some  morbid  material  in  the  blood,  which  usually  enters  into 
combination  with  the  tissue  that  is  diseased,  or  with  the  organized  product  of 
the  morbid  process.  Such  a  substance  fastens  upon  certain  spots  or  islands  on 
one  side  of  the  body,  leaving  the  surrounding  parts  unaffected ;  and  precisely 
similar  spots  or  islands  are  affected  in  like  manner  on  the  other  side.  The  con- 
clusion seems  unavoidable,  that,  however  closely  one  portion  of  skin  or  bone  may 
seem  to  resemble  another,  the  only  parts  that  are  exactly  alike  are  those  which 
repeat  each  other  symmetrically  on  the  opposite  sides  of  the  body;  for,  although 
no  power  of  artificial  chemistry  may  determine  the  difference,  the  chemistry  of 
the  living  body  makes  it  evident,  the  morbid  material  testing-out  the  parts  for 
which  it  has  the  greatest  affinity,  uniting  with  these  alone  and  passing  by  the 
rest.  It  is  continually  observable,  moreover  (as  Mr.  Paget  has  remarked),  that 
a  poison  of  the  same  kind  will  attack  corresponding  spots,  not  merely  on  the  two 
sides  of  a  single  individual,  but  also  on  the  two  sides  of  any  others  who  may 
have  imbibed  it  into  their  systems.  Thus  the  syphilitic  poison  has  its  {  seats  of 
election'  when  it  begins  to  attack  the  bones,  fixing  upon  certain  parts  of  the 
tibiae  and  of  the  skull  with  great  uniformity ;  and  in  the  Hunterian  Museum  are 
the  pelves  of  two  lions,  on  both  of  which  new  osseous  deposit  has  taken  place 
(as  the  product  of  some  disease  resembling  rheumatism  in  man)  in  a  most  com- 
plex  and  irregular  pattern,  this  being  so  similar  in  the  two,  that  almost  every 
spot  and  line  of  the  one  is  represented  in  the  other,  with  an  exactness  only  infe- 
rior to  the  symmetrical  correspondence  between  the  two  sides  of  each.2  It  has 
been  further  pointed-out  by  Dr.  W.  Budd,  as  indicated  by  the  phenomena  of 
these  diseases,  that  next  to  the  parts  which  are  symmetrically  placed,  none  are 
so  nearly  identical  in  composition  as  those  which  are  analogous,  such  as  the 
corresponding  parts  of  the  superior  and  inferior  extremities.  —  All  these  facts 
tend  to  demonstrate  the  perfect  and  most  minute  exactness  of  the  adaptation 
which  must  exist  in  the  state  of  health  between  the  blood  and  all  the  tissues,  as 
well  as  the  almost  inconceivable  minuteness  of  the  departure  from  this  adaptation 
which  may  become  a  source  of  disease ;  and  it  is  a  sure  indication  of  the  safety  with 
which  we  may  found  such  inferences  upon  them,  that  the  phenomena  of  sym- 
metrical disease  are  most  distinct,  when  the  disordered  action  is  most  conform- 

1  See  their  original  Essays  on  this  subject  in  the  "  Med.-Chir.  Trans."  vol.  xxv. 

'See  Mr.  Paget's  'Lectures  on  Nutrition,  &c.'  in  the  "  Medical  Gazette"  for  1847, 
r<ect.  i. ;  and  his  "  Lectures  on  Surgical  Pathology,"  p.  30,  Am.  Ed. 


AND     ITS    RELATION    TO    THE    LIVING    ORGANISM.    227 

able,  as  to  its  character  and  its  rate,  to  the  normal  nutrition  of  the  structure ;  it 
being  in  diseases  which  (though  dependent  upon  a  poison  in  the  blood)  are  of 
an  inflammatory  or  other  virulent  nature,  that  the  symmetry  of  the  morbid 
change  is  least  obvious. 

218.  Hence,  then,  we  are  led  to  the  conclusion,  that,  as  Treviranus  phrased  it, 
"  each  single  part  of  the  body,  in  respect  of  its  nutrition,  stands  to  the  whole 
body  in  the  relation  of  an  excreted  substance  ;"  or,  in  other  words,  each  part  of 
the  body,  by  taking  from  the  blood  the  peculiar  substances  which  it  needs  for 
its  own  nutrition,  does  thereby  act  as  an  excretory  organ,  inasmuch  as  it  removes 
from  the  blood  that  which,  if  retained  in  it,  would  be  injurious  to  the  nutrition 
of  the  body  generally.     Thus,  the  phosphates  which  are  deposited  in  our  bones, 
are  as  effectually  excreted  from  the  blood,  and   as  completely  prevented  from 
acting  injuriously  on  other  tissues,  as  are  those  which  are  discharged  with  the 
urine.  —  The  applications  of  this  doctrine  have  been  greatly  extended  by  Mr. 
Paget,1  who  has  given  the  following  among  other  examples  of  its  bearing  upon 
the  general  relations  between  the  blood  and  the  tissues.     The  hairy  covering 
may  be  considered  to  serve,  over  and  above  its  local  purposes,  for  the  removal 
of  certain  components  of  the  blood,  which  would  be  injurious  to  its  constitution 
if  they  remained  and  accumulated  in  it;  and  accordingly  we  do  not  find  that  its 
development  is  delayed,  until  near  the  period  when  its  protection  will  be  required ; 
for  a  complete  coat  (the  lanuyo  of  the  human  fo3tus)  is  formed  in  the  foetus  of 
mammals  generally,  whilst  they  are  still  within  the  uterus,  removed  from  all 
those  conditions  against  which  hair  is  a  defence;  and  this  coat  is  shed  very  soon 
after  birth,  being  replaced  by  another  of  wholly  different  colour,  the  growth  of 
which  had  begun  within  the  uterus.     The  same  principle  leads  to  the  apprehen- 
sion of  the  true  import  of  the  hair,  which  exists  in  a  kind  of  rudimental  state 
on  the  general  surface  of  our  bodies;  and  thence  to  the  real  meaning  of  the 
existence  of  other  organs  which  permanently  remain  in  a  rudimental  state,  such 
as  the  mammary  glands  of  the  male.     For,  as  Mr.  Paget  justly  remarks  (loc. 
cit.)  "  these  rudimental  organs  certainly  do  not  serve,  in  a  lower  degree,  the 
same  purposes  as  are  served  by  the  homologous  parts  which  are  completely  de- 
veloped in  other  species,  or  in  the  other  sex.     To  say  they  are  useless,  is  con- 
trary to  all  we  know  of  the  absolute  perfection  and  all-pervading  purpose  of 
creation ;  to  say  they  exist  merely  for  the  sake  of  conformity  to  a  general  type 
of  structure,  is  surely  unphilosophical,  for  the  law  of  unity  of  organic  types  is, 
in  larger  instances,  not  observed,  except  when  its  observance  contributes  to  the 
advantage  of  the  individual.     No :  all  these  rudimental  organs  must,  as  they 
grow,  be  as  excretions  serving  a  definite  purpose  in  the  economy,  by  removing 
their  appropriate  materials  from  the  blood,  thus  leaving  it  fitter  for  the  nutrition 
of  other  parts,  or  adjusting  the  balance  which  might  otherwise  be  disturbed  by 
the  formation  of  some  other  part.     Thus  they  minister  to  the  self-interest  of  the 
individual ;  while,  as  if  for  the  sake  of  wonder,  beauty,  and  perfect  order,  they 
are  conformed  with  the  great  law  of  unity  of  organic  types,  and  concur  with  the 
universal  plan  observed  in  the  construction  of  organic  beings." 

219.  But  further,  there  are  many  examples  in  which  the  presence  of  a  certain 
substance  in  the  Blood,  appears  to  determine  the  formation  of  the  particular 
tissue,  of  which  that  substance  is  the  appropriate  pabulum  (§  340).     And  thus, 
as  the  abstraction  of  the  material  required  for  each  part  leaves  the  blood  in  a 
state  fitted  for  the  nutrition  of  other  parts,  it  seems  to  follow,  as  Mr.  Paget  haa 
further  remarked  (loc.  cit.).  that  such  a  mutual  dependence  exists  amongst  the 
several  parts  and  organs  of  the  body,  as  causes  the  evolution  of  one  to  supply 
the  conditions  requisite  for  the  production  of  another ;  and  hence,  that  the  order 
in  which  the  several  organs  of  the  body  appear  in  the  course  of  development, 
while  it  is  conformable  to  the  law  of  imitation  of  the  parent,  and  to  the  law  of 

1  "  Lectures  on  Surgical  Pathology,"  Lect.  n. 


228      OF  THE  BLOOD,  ITS  VITAL  PROPERTIES, 

progressive  ascent  towards  the  higher  grade  of  being,  is  yet  the  immediate  result 
of  changes  effected  in  the  condition  of  the  blood  by  the  antecedent  operations. 
And  this  view  is  confirmed  by  many  circumstances,  which  indicate  that  certain 
organs  really  do  stand  in  such  a  complemental  relation  to  one  another  as  it  im- 
plies ;  a  large  class  of  facts  of  this  order  being  supplied  by  the  history  of  the 
evolution  of  the  generative  apparatus,  and  by  that  of  the  concurrent  changes  in 
other  organs  (especially  the  tegumentary)  which  are  found  to  be  dependent  upon 
it,  although  there  is  no  direct  functional  relation  between  them.  Thus,  the 
growth  of  the  beard  in  man  at  the  period  of  puberty,  is  but  a  type  of  a  much 
more  important  change  which  takes  place  in  many  animals  with  every  recurrence 
of  the  period  of  generative  activity.  This  is  most  obvious  in  birds,  whose 
plumage,  at  the  commencement  of  the  breeding  season,  becomes  (especially  in 
the  male)  more  highly  coloured,  besides  being  augmented  by  the  growth  of  new 
feathers ;  but  when  the  sexual  organs  pass  into  their  state  of  periodic  atrophy, 
the  plumage  at  once  begins  to  assume  a  paler  and  more  sombre  hue,  and  many 
of  the  feathers  are  usually  cast,  their  nutrition  being  no  longer  kept-up.  It  is  a 
matter  of  common  observation,  that  the  deficiency  of  hair  on  the  face  (where 
this  is  not,  as  among  the  Asiatics,  a  character  of  race)  is  usually  concurrent  with 
a  low  amount  of  generative  power  in  the  male,  and  may  be  considered  as  indi- 
cative of  it;  whilst,  on  the  other  hand,  the  presence  of  hair  on  the  upper  lip  and 
chin  of  the  female  is  indicative  of  a  tendency  in  the  general  organization  and 
mental  character  towards  the  attributes  of  the  male,  and  of  a  deficiency  in  those 
which  are  typical  of  the  female.  If,  moreover,  the  development  of  the  male 
organs  be  prevented,  the  evolution  of  the  beard  does  not  take  place;  whilst  the 
cessation  or  the  absence  of  activity  in  the  female  organs  is  often  attended  by  a 
strong  growth  of  hair  on  the  face,  as  well  as  by  other  changes  that  may  be  at- 
tributed to  the  presence  of  some  special  nutritive  material  in  the  blood,  for  which 
there  is  no  longer  any  other  demand.  This,  again,  shows  itself  yet  more  strongly 
in  Birds;  among  which  (as  Hunter  long  since  pointed-out1)  it  is  no  uncommon 
occurrence  for  the  female,  after  ceasing  to  lay,  to  assume  the  plumage  of  the 
male,  and  even  to  acquire  other  characteristic  parts,  as  the  spurs  in  the  fowl  tribe. 
Moreover,  it  has  been  ascertained  by  the  experiments  of  Sir  Philip  Egerton,  that 
if  a  buck  be  castrated  while  his  antlers  are  growing  and  are  still  covered  with 
the  ( velvet/  their  growth  is  checked,  they  remain  as  if  truncated,  and  irregular 
nodules  of  bone  project  from  their  surfaces;  whilst,  if  the  castration  be  performed 
when  the  antlers  are  full-grown,  these  are  shed  nearly  as  usual  at  the  end  of  the 
season,  but  in  the  next  season  are  only  replaced  by  a  kind  of  low  conical 
stumps. 

220.  That  these  and  similar  changes  in  the  development  of  organs  are  im- 
mediately determined  by  the  condition  of  the  circulating  fluid,  that  is,  by  the 
presence  or  absence  of  the  appropriate  l  pabulum'  for  the  parts  in  question, 
would  further  seem  likely  from  the  fact,  that  they  may  be  artificially  induced  by 
circumstances  which  directly  affect  the  condition  of  the  blood.  This  has  been 
shown  by  Mr.  Yarrell,2  in  regard  to  the  assumption  of  the  male  plumage  by  the 
female;  and  a  still  more  remarkable  and  satisfactory  proof  is  furnished  by  the 
conversion  of  the  '  worker'  larva  of  the  Bee  into  a  perfect  ( queen/  solely  through 
a  change  of  diet.3  And  thus  we  are  led  to  feel  that  Mr.  Paget's  doctrine  of 
'  complementary  nutrition/  whilst  it  has  the  advantage  of  grouping-together  a 
great  number  of  phenomena  which  would  otherwise  seem  to  be  unrelated  to  each 
other,  really  possesses  a  definite  foundation  in  well-known  and  universally-ad- 
mitted facts,  which  can  scarcely  be  viewed  in  any  other  light.  To  use  his  own 
expression  of  it,  u  the  development  of  each  organ  or  system,  co-operating  with 

1  « Account  of  an  Extraordinary  Pheasant,'  in  "Hunter's  Works,"  Palmer's  edit,  vol. 
JT.  p.  44. 

"  Philosophical  Transactions,"  1827.         " «  Princ.  of  Comp.  Phys.,"  \  119,  Am.  Ed 


AND     ITS     RELATION     TO    THE     LIVING    ORGANISM.      229 

the  self-development  of  the  blood,  prepares  it  for  the  formation  of  some  other 
organ  or  system;  till,  by  the  successive  changes  thus  produced,  and  by  its  own 
development  and  increase,  the  blood  is  fitted  for  the  maintenance  and  nutrition 
of  the  completed  organism."  (Op.  cit.,  p.  29.)  And  further,  "where  two  or 
more  organs  are  thus  manifestly  connected  in  nutrition,  and  not  connected  in  the  i 
exercise  of  any  external  office,  their  connection  is  because  one  is  partly  formed 
of  materials  left  in  the  blood  on  the  formation  of  the  other;  so  that  each,  at  the 
same  time  that  it  discharges  its  own  proper  and  external  office,  maintains  the 
blood  in  the  condition  most  favourable  to  the  formation  of  the  other.  (Op.  cit., 
p.  32.) 

221.  Thus,  then,  the  precise  condition  of  the  Blood  at  any  one  time,  is 
dependent  upon  a  vast  variety  of  antecedent  circumstances,  and  can  scarcely  be 
the  same  at  any  two  periods  of  life.  Yet  we  find  that,  taken  as  a  whole,  it 
exhibits  such  a  remarkable  constancy  in  its  leading  features,  that  we  can  scarcely 
fail  to  recognise  in  it  some  such  capacity  for  self-development  and  maintenance, 
as  that  which  the  solid  tissues  are  admitted  to  possess.  And  this  idea  may  be 
thought  less  strange,  when  it  is  borne  in  mind  that  the  first  blood  is  formed  by 
the  liquefaction  of  the  primordial  cells  of  the  embryo;  and  that,  notwithstanding 
the  continual  change  in  its  components,  it  still  retains  its  identity  through  life,  in 
no  less  a  degree  than  a  limb  or  an  eye,  the  material  changes  in  which,  though 
less  rapid,  are  not  less  complete.  Looking,  again,  to  the  undoubted  vitality  of 
the  Corpuscles,  and  to  the  strong  ground  for  regarding  the  Fibrin  also  as  an  in- 
strument of  vital  force,  we  cannot  but  perceive  that  the  Life  of  the  Blood  is  as 
legitimate  a  phrase,  and  ought  to  carry  as  much  meaning  in  it,  as  the  Life  of 
a  Muscle.  And  as  the  one  has  a  period  of  growth,  development,  and  decline,  so 
must  the  other. — This  view  is  borne-out,  not  merely  by  those  palpable  differences 
in  the  composition  of  the  blood  at  different  ages,  which  are  detectable  by  our 
rude  methods  of  examination ;  but  also  by  those  alterations  in  the  tendency  to 
particular  constitutional  diseases,  which  at  the  same  time  mark  the  advance  of 
life,  and  indicate  minute  and  otherwise  inappreciable  alterations  in  the  circulating 
fluid.  For  it  is  obvious  that  since  the  poison  of  small-pox,  for  example,  less 
readily  produces  its  characteristic '  zymosis'  in  the  blood  of  the  adult  than  it  does 
in  that  of  the  child,  tho  latter  must  differ  from  the  former,  either  in  composition 
or  in  vital  endowments;  and  that  since  the  tendency  to  ' fatty  degeneration ' 
of  the  tissues  generally,  shows  itself  in  a  far  stronger  degree  in  the  aged  person 
than  in  the  adult,  this  is  likely  to  be  in  part  owing  to  the  condition  of  the  blood, 
in  which,  according  to  the  observations  of  Becquerel  and  Rodier,  there  is  a  decided 
and  progressive  increase  of  cholesterin  after  the  age  of  40  or  50  years. 

222.  Thus,  then,  we  seem  justified  in  the  belief  that  the  Blood,  like  the  solid 
tissues,  has  a  formative  power  of  its  own,  which  it  exerts  in  the  appropriation  of 
the  new  material  supplied  to  it  from  the  food ;  and  that  like  all  the  other  parta 
descended  from  the  component  cells  of  the  germinal  mass,  it  goes  through  a  suc- 
cession of  phases,  which  are  partly  the  cause,  and  partly  the  effect,  of  develop- 
mental changes  in  the  organism  generally.  So  long  as  the  operations  of  Nutrition 
are  normally  carried  on,  the  materials  that  are  withdrawn  by  the  several  parts  of 
the  body  may  be  considered  so  far  to  balance  one  another,  that  no  waste  is 
incurred  from  this  source;  and  if  the  amount  of  new  matter  introduced  be 
merely  the  equivalent  of  that  which  is  required  for  the  nutritive  operations, 
nothing  else  will  occasion  a  demand  for  elimination,  save  the  products  of  the  dis- 
integration of  the  tissues,  which  are  received  back  into  the  blood  for  this  pur- 
pose. But  it  must  be  very  rarely  that  this  balance  is  precisely  maintained  for 
any  length  of  time,  since  a  multitude  of  circumstances  are  continually  occurring 
to  derange  it;  the  most  frequent,  perhaps,  being  the  ingestion  of  certain 
nutritive  materials  in  greater  quantity  than  they  are  required.  And  we  then  find 
that  the  excretory  organs  take  upon  themselves  a  supplemental  action  for  the 
removal  of  the  superfluity ;  the  kidneys  being  especially  charged  with  this  duty 


230          oi    THE   BLOOD;   ITS   VITAL   PROPERTIES, 

in  the  case  of  azotized  and  saline  matters,  and  the  liver  and  lungs  in  regard  to 
hydrocarbonaceous  substances.  It  is  obviously  of  importance,  however,  to  over- 
task these  organs  as  little  as  possible  j  and  when  such  superfluity  is  becoming  a 
source  of  disease,  the  obvious  treatment  is  rather  to  prevent  it  from  being  thrown 
upon  them  for  separation,  by  diminishing  the  supply  of  aliment  generally,  or  of 
some  particular  article  of  diet,  than  to  excite  them  to  increased  activity  by  stimu- 
lating medicines. 

223.  The  self-maintaining  power  of  the  Blood  is  yet  more  shown  in  the 
phenomena  of  Disease ;  and  especially  in  its  spontaneous  recovery  of  its  normal 
condition,  after  the  most  serious  perversions  \  as  we  see  more  particularly  in 
febrile  diseases  of  definite  type  (such,  for  example,  as  the  Exanthemata,  Typhoid, 
Typhus,  &c.),  of  whose  origin  in  the  introduction  of  specific  poisons  into  the 
blood  there  is  no  reasonable  ground  for  doubt.  In  studying  the  mode  in  which 
these  and  other  '  morbid  poisons '  act  upon  the  blood,  and  through  it  upon  the 
system  at  large,  we  may  derive  important  assistance  from  a  previous  inquiry  into 
the  history  of  the  action  of  those  poisonous  agents,  which  from  their  being  moro 
readily  traceable  by  chemical  analysis,  can  be  more  satisfactorily  made-out.  Such 
an  inquiry  has  a  most  important  bearing,  also,  on  the  modus  operandi  of  medi- 
cines.— The  operation  of  medicinal  or  poisonous  substances  for  the  most  part 
depends  upon  the  power  which  they  possess,  when  introduced  into  the  current  of 
the  circulation,  of  effecting  some  determined  change  in  the  chemical  and  thereby 
in  the  vital  condition,  either  of  the  components  of  the  blood,  or  of  some  one  or 
more  of  the  tissues  which  it  nourishes  ]  and  their  determination  to  some  special 
part  or  organ  must  be  attributed  to  the  same  kind  of  elective  affinity,  as  that  by 
which  the  normal  constituents  of  the  blood  are  so  determined  (§  217).  Now  of 
nearly  all  these  substances  it  may  be  said,  that  the  system,  if  left  to  itself,  tends 
to  free  itself  from  them,  provided  time  be  allowed  for  it  to  do  so;  and  that,  when 
death  results  from  their  introduction  into  it,  the  fatal  result  is  to  be  attributed  to 
the  fact,  that  the  disorganization  of  structure  and  disturbance  of  function  are  too 
rapid  and  violent  to  allow  the  eliminating  process  to  be  set  in  efficient  operation. 
When  smaller  doses  are  taken,  their  effects  are  evanescent,  unless  the  abnormal 
action  to  which  they  may  have  given  rise  is  of  a  kind  to  perpetuate  itself; !  and 
their  cessation  is  obviously  attributable  to  the  removal  of  the  agent  from  the 
system,  whereby  the  continuance  of  its  deleterious  agency  is  prevented.  Of  this 
removal,  we  have  of  course  the  most  satisfactory  evidence  in  the  case  of  those 
substances,  which  can  be  detected  by  ordinary  chemical  tests  in  the  excretions. 
Thus,  as  a  general  rule,  alkaline  and  earthy  salts  that  have  been  absorbed  into 
the  blood,  are  discharged  in  the  urinary  secretion,  which  is  itself  increased  in 
amount,  showing  that  their  action  is  specially  determined  towards  the  kidneys. 
So,  again,  arsenic,  tartarized  antimony,  and  a  variety  of  other  metallic  substances, 
have  also  been  detected  in  the  urine,  for  some  days  after  they  have  been  ingested ; 
showing  that  their  elimination  is  the  work  of  time.  On  the  other  hand,  the  salts 
of  copper  appear  rather  to  be  removed  from  the  blood  by  the  liver,  and  also  by 
the  bronchial  secretion.  And  lead,  which  passes-off  but  little  by  the  ordinary 
excretions,  is  withdrawn  from  the  circulation  by  various  tissues  and  organs,  but 
particularly  by  certain  parts  of  the  muscular  apparatus,  with  the  substance  of 
which  it  becomes  incorporated,  producing  a  most  injurious  influence  upon  its  vital 
endowments.2  The  only  exception  to  the  general  rule  above  stated,  seems  to  be 
in  the  case  of  those  medicines,  which  have  what  is  called  a  '  cumulative '  tendency ; 
this  tendency  being,  in  fact,  simply  the  result  of  their  want  of  stimulating  influ- 

1  Such  a  perpetuation  is  seen  in  the  chronic  inflammation,  thickening,  and  contraction, 
of  the  oesophageal  walls,  consequent  upon  the  deglutition  of  strong  acids  and  causlio 
alkalies. 

a  This  has  been  shown  by  the  analyses  of  M.  Devergie  (see  the  "  Traite  des  Maladies 
de  Plomb,"  of  M.  Tanquerel,  torn.  ii.  pp.  401 — 6),  and  of  Prof.  Miller  (see  Dr.  W. 
J3udd's  essay  on  « The  Symmetry  of  Disease,'  in  the  "  Medico-Chirurgical  Transactions," 
vol.  xxv.). 


AND    ITS    RELATION    TO    THE    LIVING    ORGANISM.     281 

upon  the  excretory  organs,  whose  functional  activity  is  rather  impeded  than 
promoted  by  them.  This  is  pre-eminently  the  case  in  regard  to  lead,  which  is 
probably  the  most  cumulative  poison  with  which  we  are  acquainted ;  its  continual 
introduction  in  doses  of  even  extreme  minuteness,  being  capable,  if  sufficiently 
prolonged,  of  causing  the  most  serious  disturbance  in  almost  every  function  in 
the  economy.  Even  here,  it  is  rather  in  the  tissues,  than  in  the  blood,  that  it 
accumulates, — as  is  indicated  by  a  variety  of  facts,  but  more  especially  by  the 
difficulty  with  which  it  is  eliminated  from  the  system,  by  means  that  would  be 
probably  effectual  in  removing  it  from  the  circulating  current; — and  thus  we  see 
that,  in  default  of  other  provision  for  maintaining  the  purity  of  the  blood,  the 
whole  body  (so  to  speak)  acts  as  an  excretory  apparatus,  and  draws  into  itself  the 
noxious  substance. 

224.  There  is  a  large  number  of  cases,  moreover,  in  which,  although  the 
poisonous  or  medicinal  substances  cannot  be  traced  in  the  excretions  by  chemical 
tests,  their  effects,  when  moderate  doses  have  been  taken,  pass-off  so  completely, 
that  there  can  be  no  doubt  of  their  not  being  any  longer  present,  as  such,  in  the 
system  •  and  the  substances  of  this  class  are  of  a  nature  and  composition  which 
render  them  peculiarly  susceptible  of  change,  when  subjected  to  the  influences 
which  they  must  encounter  in  the  living  body,  and  more  especially  when  exposed 
in  a  state  of  very  fine  division  to  the  agency  of  oxygen.  A  familiar  exemplifi- 
cation of  this  mode  of  elimination  of  poisons,  is  furnished  by  the  transient  dura- 
tion of  the  effects  of  a  dose  of  Alcohol,  even  when  this  is  large  enough  to  pro- 
duce sensibility ;  recovery  from  them  being  merely  a  question  of  time,  provided 
that  the  state  of  torpor,  produced  by  the  action  of  this  poison  on  the  centre  of 
the  respiratory  movements,  be  not  so  profound  as  to  occasion  Asphyxia,  or  that 
death  do  not  result  (as  sometimes  happens  when  the  poison  is  taken  in  a  state  of 
concentration)  from  the  immediate  shock  to  the  nervous  system.  Now  the  quan- 
tity of  alcohol  which  passes-off  by  the  ordinary  excretions  is  extremely  slight ;  in 
fact,  this  substance  can  seldom  be  detected  in  them.  But  there  can  be  no  reason- 
able doubt  that  the  elimination  of  the  alcohol  is  due  to  its  oxidation  whilst  pass- 
ing through  the  circulating  system,  so  that  it  is  excreted  by  the  lungs  in  the  form 
of  carbonic  acid  and  water;  and  if  confirmation  of  this  view  were  needed,  it  is 
afforded  by  the  tolerance  of  large  doses  of  alcohol,  which  is  shown  when  it  is 
subjected  with  peculiar  rapidity  to  the  combustive  operation,  as  during  continued 
exposure  to  severe  cold  or  prolonged  muscular  exertion,  or  in  the  exhaustion  of 
wasting  diseases  when  no  other  combustive  material  remains  in  the  body.  The 
same  explanation  is  obviously  applicable  to  the  parallel  phenomena  which  present 
themselves  in  the  action  of  Opium,  Strychnia,  Prussic  acid,  &c.  With  all  these, 
also,  the  question  of  life  or  death  is  one  of  time;  for  if  the  fatal  result  do  not 
speedily  follow  the  absorption  of  the  poison  into  the  blood,  the  patient  gradually 
recovers  from  its  effects ;  and  the  most  effectual  treatment  consists  in  the  arti- 
ficial maintenance  of  the  respiratory  movements,  which  the  influence  of  these 
poisons  upon  the  nervous  centres  might  otherwise  suspend.  These  poisons 
cannot  be  detected  in  the  circulating  fluid  by  their  sensible  or  chemical  charac- 
ters, if  a  short  interval  has  elapsed  subsequently  to  their  absorption ;  thus  it  has 
been  found  by  Dr.  Lonsdale  that  the  odour  of  prussic  acid  cannot  be  perceived 
in  the  blood  or  in  the  cavities,  when  life  had  been  prolonged  beyond  15  minutes, 
although,  when  death  took  place  within  a  shorter  time,  the  poison  might  be 
detected  in  the  body  by  its  odour  alone  for  eight  or  nine  days  afterwards ;  and 
the  presence  of  morphia  ceases  to  be  recognizable  by  the  ordinary  chemical  tests, 
within  a  short  time  after  it  has  been  taken  into  the  circulating  current.  — Even 
with  regard  to  certain  poisons  of  this  unstable  class,  however,  there  is  evidence 
that  they  pass  into  the  urine  and  are  thus  eliminated,  without  undergoing  any 
change  that  impairs  their  physiological  action ;  this  evidence  being  afforded  in 
the  effects  of  the  re-ingestion  of  the  urine,  either  by  the  individuals  themselves, 
or  by  others.  A  very  curious  example  of  this  kind  is  afforded  by  the  intoxi- 


232    OF  THE  BLOOD;  ITS  VITAL  PROPERTIES, 

eating  fungus,  Amanita  muscaria,  which  is  used  by  some  of  the  inhabitants  of 
the  north-eastern  parts  of  Asia,  in  the  same  manner  as  alcoholic  liquors  by  other 
nations.  Its  effects,  like  those  of  other  excitants,  have  a  limited  duration;  for 
a  man  who  is  intoxicated  by  it  one  day,  '  sleeps  himself  sober'  by  the  next.  His 
restoration  is  due,  however,  not  to  his  repose,  but  to  the  elimination  of  the  poison 
which  takes  place  during  the  interval  ;  for  if  he  drink  a  cup  of  his  urine  the 
next  morning,  he  is  yet  more  powerfully  intoxicated  than  he  was  the  preceding 
day;  and  this  fluid  has  the  same  effect  upon  any  other  individual,  into  whose 
urine  the  active  principle  then  passes ;  so  that,  according  to  the  testimony  of 
travellers,  the  intoxicating  agent  may  be  transmitted  in  this  manner  through  five 
or  six  persons,  a  small  stock  at  the  commencement  thus  serving  to  maintain  a 
week's  debauch.  Results  of  the  same  order  have  been  obtained  by  Dr.  Letheby, 
in  regard  to  opium,  belladonna,  hemlock,  aconite,  &c. ;  the  passage  of  these  sub- 
stances into  the  urine  being  proved  by  the  induction  of  their  characteristic 
effects,  when  that  fluid  was  administered  to  other  animals.  It  is  probable  that 
the  appearance  of  these  substances  in  the  urine,  is  due  to  their  presence  in  the 
blood  in  such  quantity,  that  the  oxidizing  process  does  not  promote  their  elimina- 
tion through  the  lungs  with  sufficient  rapidity. 

225.  Between  the  substances  which  admittedly  rank  as  poisons,  and  those 
which  are  reckoned  as  materics  morborum,  no  definite  line  of  demarcation  can 
be  drawn ;  and  the  train  of  symptoms  produced  by  the  operation  of  the  former, 
is  really  as  much  a  disease  as  that  which  results  from  the  presence  of  the  latter. 
The  connection  is,  in  fact,  established,  by  those  '  animal  poisons'  which  are  the 
result  of  decomposition  either  within  or  without  the  body;  such  as  that  of  the 
'pustule  maligne,'  or  of  the  flesh  of  animals  suffering  under  disease,  on  the  one 
hand,  or  the  'cheese-poison/  'sausage-poison/  &c.,  on  the  other.  —  It  maybe 
admitted  that  our  belief  in  a  specific  material  cause  for  a  great  part  of  the  effects 
set-down  to  the  action  of  'morbid  poisons/  is  merely  inferential;  and  there  are 
many  persons  to  whom  their  exhibition  in  a  tangible  form  seems  to  afford  the 
only  convincing  evidence  of  their  existence.  But  it  must  be  remembered  that 
the  evidence  of  Chemistry  itself  is  often  purely  inferential ;  for  we  recognize 
the  presence  of  a  chemical  substance,  not  merely  by  obtaining  it  in  a  separate 
form,  but  by  witnessing  the  reactions  which  it  displays  with  various  tests ;  and 
there  is  one  substance,  fluorine,  which  has  never  hitherto  been  isolated,  and  yet 
of  whose  existence  no  chemist  would  hint  a  doubt.  Now  it  is  the  human  body, 
which  forms  the  appropriate  testing-apparatus  of  'morbid  poisons;'  and  even  if 
we  could  always  obtain  them  in  a  separate  state,  and  could  subject  them  to  chemi- 
cal analysis,  we  should  know  much  less  of  their  most  important  properties,  than 
that  which  we  can  ascertain  by  observation  of  their  actions  in  the  living  system ; 
this  alone  affording  the  means  of  judging  of  their  dynamical  character,  which  is 
of  far  more  importance  than  a  knowledge  of  their  chemical  composition.  In  the 
case  of  those  poisons  which  are  capable  of  being  introduced  by  inoculation,  we 
have,  indeed,  the  required  proof  of  their  material  existence ;  and  this  proof  is 
capable  of  being  extended  by  a  safe  analogy  to  infectious  diseases  generally. 
For,  if  small-pox  can  be  communicated  by  the  inhalation  of  an  atmosphere 
tainted  with  the  exhalations  of  a  person  already  affected  with  it,  as  well  as  by  the 
introduction  of  the  fluid  of  the  cutaneous  pustule  into  the  blood  of  another,  it 
can  scarcely  admit  of  a  question,  that  the  same  poisonous  agent  is  transmitted  in 
both  cases,  although  through  different  media,  and  that  it  has  as  real  an  existence 
in  the  transferred  air,  as  in  the  transferred  pus.  Diseases,  then,  which  are* 
capable  of  being  transmitted  in  both  these  methods,  form  the  connecting  link- 
between  those  resulting  from  ordinary  toxic  agents,  and  those  which  must  be 
assumed  to  depend  upon  a  subtle  poison,  of  which  the  air  alone  is  the  vehicle, — 
such,  for  example,  as  malarious  fevers;  this  assumption  being  required  by  all 
the  rules  of  logic,  as  the  only  one  which  will  account  for  the  phenomena  to  be 
explained,  and  therefore  possessing  a  claim  to  be  accepted  as  an  almost  certain 


AND    ITS     RELATION    TO    THE    LIVING    ORGANISM.    233 

truth.  There  is  a  strongly  marked  difference,  however,  between  the  modus 
operandi  of  the  toxic  agents  whose  action  has  been  previously  examined,  and 
that  of  the  morbid  poisons  we  are  now  considering;  for  whilst  the  former  possess 
a  certain  definite  action,  the  intensity  of  which  (cccteris  paribus)  is  proportionate 
to  the  quantity  that  is  in  operation,  and  which  is  usually  determined,  in  virtue 
of  the  'elective  affinity'  already  spoken-of,  to  some  particular  organ  or  tissue, — 
the  latter  act  primarily  upon  the  blood,  influencing  the  system  at  large  through 
the  changes  which  they  produce  in  its  constitution ;  and  their  potency  depends 
rather  upon  the  susceptibility  of  the  blood  to  their  peculiar  influence,  than  upon 
the  quantity  of  the  poison  that  may  be  introduced  into  it. 

226.  Of  the  existence  of  such  susceptibility,  as  a  '  predisposing  cause*  of 
Zymotic^  disease,  there  cannot  be  the  slighest  doubt.  In  the  case  of  the  Exan- 
themata and  Hooping-cough,  we  see  that  it  is  congenital,  and  is  usually  removed 
by  the  occurrence  of  one  attack  of  the  disease  (although  this  is  not  a  uniform 
protection)  ;  but  the  liability  even  to  these  varies  greatly  in  different  individuals, 
and  at  different  times  in  the  same  individual.  And  with  regard  to  other  zymotic 
diseases,  the  liability  to  which  is  not  thus  limited,  all  extended  observation  con- 
curs in  showing  that  it  is  augmented  by  anything  which  tends  to  depress  the 
vital  powers  of  the  system,  and  more  particularly  by  any  cause  which  obstructs 
the  due  purification  of  the  blood,  by  the  elimination  of  the  products  of  decom- 
position. Thus,  it  will  be  shown  hereafter  (§§  330,  331),  that  no  antecedent 
condition  has  been  found  more  efficacious  in  augmenting  the  fatality  of  Cholera, 
than  overcrowding  ;  which  compels  those  who  are  subjected  to  it,  to  be  constantly 
breathing  an  atmosphere  not  only  charged  with  carbonic  acid,  but  laden  with 
putrescent  emanations ;  and  which  thus  favors  the  accumulation  of  decomposing 
matter  in  the  blood,  which  serves  as  the  most  appropriate  soil  for  the  seeds  of  the 
disease.  And  what  is  true  of  Cholera  has  been  found  to  be  true  of  Zymotic 
diseases  in  general;  the  very  same  fermentable  matter  in  the  blood  serving  for 
the  development  of  almost  any  kind  of  zymotic  poison  that  may  be  received  into 
the  system,  whether  from  the  atmosphere,  or  from  the  bodies  of  those  who  have 
already  been  subjects  of  the  disease.  — Now  that  what  has  been  here  spoken  of 
as  *  fermentable  matter/  is  not  a  mere  hypothetical  entity,  but  has  a  real  material 
existence,  appears  from  this  consideration;  that  in  all  those  conditions  of  the 
system  in  which  we  know  that  decomposition  is  going-on  to  an  unusual  extent, 
and  in  which  there  is  a  marked  tendency  to  putrescence  in  the  excreted  matters, 
we  witness  such  a  peculiar  liability  to  zymotic  diseases,  as  clearly  indicates  that 
the  state  of  the  blood  is  peculiarly  favourable  to  the  action  of  the  zymotic  poison. 
This  is  pre-eminently  the  case  in  the  puerperal  state,  in  which  the  tissue  of  the 
uterus  is  undergoing  rapid  disintegration,  its  vital  force  having  been  expended 
(§  349) ;  for  there  is  now  abundant  evidence,  that  the  -contact  of  decomposing 
matters  which  would  be  innocuous  at  other  times,  is  capable  of  so  acting  upon 
the  blood  of  the  parturient  female,  as  to  induce  that  most  fatal  zymosis  which  is 
known  as  '  puerperal  fever.' 2  And  her  peculiar  liability  is  in  no  respect  more 
manifest  than  in  this ;  that  the  poison  by  which  she  is  affected  may  have  lain 
dormant  for  weeks  or  months,  for  want  of  an  appropriate  nidus,  and  will  yet  ex- 
hibit its  full  potency  on  the  very  first  case  in  which  opportunity  may  be  given 

1  The  term  zymotic  is  a  very  convenient  designation,  which,  originally  suggested  by 
D.  W.  Farr,  has  of  late  gained  general  currency,  for  that  class  of  diseases  whose  pheno- 
mena may  be  attributed  to  the  operation  of  a  morbid  poison  of  the  nature  described  above; 
this  operation  bearing  a  strong  analogy  to  that  of  'ferments.' 

a  For  a  most  marked  and  convincing  example  of  this  kind,  see  Dr.  Routh's  paper  ou 
'The  Causes  of  the  Endemic  Puerperal  Fever  of  Vienna,'  in  the  " Medico-Chirurgical 
Transactions,"  vol.  xxxii.  p.  27. — That  the  poison  which  developes  puerperal  fever,  may 
be  conveyed  from  patients  labouring  under  almost  any  other  form  of  Zymotic  disease 
tending  to  putrescence,  that  is  propagable  by  contact, — such  as  scarlatina,  small-pox,  o«- 
erysipelas, — is  now  the  general  opinion  of  most  pathologists  who  have  paid  special  atten 
tion  to  the  subject. 


234    or  THE  BLOOD;  ITS  VITAL  PROPERTIES, 

for  its  introduction  into  the  system  of  a  puerperal  patient.1  The  same  kind  of 
liability  is  displayed  in  the  subjects  of  severe  injuries,  among  whom,  also,  there 
is  not  only  a  state  of  general  depression  of  the  vital  powers,  but  also  a  special 
source  of  decomposing  matter  in  the  system ;  for  there  is  evidence  that  '  surgical 
fever'  may  be  induced  in  them,  by  the  introduction  of  a  zymotic  poison  derived 
from  a  variety  of  external  sources  (amongst  others,  from  patients  affected  with 
puerperal  fever),  such  as  would  have  no  effect  upon  a  healthy  subject;  and,  more- 
over, that  overcrowding  in  hospitals  has  a  special  tendency  to  increase  this  lia- 
bility.2 So,  again,  an  excess  of  muscular  exertion,  producing  an  unusual  'waste' 
of  tissue,  especially  when  the  elimination  of  the  products  of  this  waste  is  inter- 
fered-with  by  imperfect  respiration,  is  well  known  to  engender  a  peculiar  liability 
to  zymotic  disease;  arid  this,  too,  finds  its  explanation  in  the  same  principle.3  — 
Thus,  then,  we  may  affirm  with  strong  confidence,  that  the  special  liability  to 
Zymotic  diseases,  which  determines  their  selection  of  individuals  when  epidemi- 
cally prevalent,  depends  upon  the  previous  condition  of  the  blood  of  the  subjects 
who  are  thus  '  predisposed '  to  their  invasion ;  and  more  especially  on  the  pre- 
sence of  fermentable  matters,  resulting  from  the  ordinary  process  of  disintegra- 
tion, which,  in  the  state  of  perfect  health,  are  eliminated  as  fast  as  they  are 
formed,  but  of  which  an  accumulation  is  prone  to  take  place,  either  when  there 
are  special  sources  of  an  augmented  production,  or  when  the  excretory  operations 
are  imperfectly  performed.4  And  it  would  further  appear,  that  the  continued 
accumulation  of  such  matters  may  itself  become  a  source  of  certain  forms  of 
Zymotic  disease,  which  may  thus  originate  de  novo  in  the  system,  and  which 
may  thence  be  propagated  to  other  individuals  in  some  of  the  modes  already 
specified ;  of  this  we  have  notable  examples  in  hydrophobia,  erysipelas,  and  the 
(  pustule  maligne.' 

227.  Tt  is  not  only,  however,  in  the  class  of  Zymotic  diseases,  that  we  seem 
distinctly  able  to  trace  the  operation  of  morbid  poisons  circulating  in  the  blood ; 
for  there  are  numerous  other  maladies,  of  whose  origin  in  a  like  condition  there 
can  be  no  reasonable  doubt ;  and  these  are  in  some  respects  more  closely  ana- 
logous than  the  preceding,  to  the  disordered  states  induced  by  the  introduction 
of  toxic  agents.  For  in  those  of  which  we  have  now  to  speak,  the  action  is 
destitute  of  any  analogy  to  fermentation,  and  its  potency  is  strictly  proportionate, 
in  each  case,  to  the  amount  of  the  dose  that  is  in  operation.  Here,  too,  we  have 
a  connecting  link  afforded  by  those  disordered  states  of  the  system,  which  depend 
upon  an  undue  accumulation  of  poisons  normally  generated  within  it,  in  conse- 
quence of  some  obstacle  to  their  elimination.  Thus,  the  train  of  symptoms 
which  is  consequent  upon  the  retention  of  urea  in  the  blood,  so  much  resembles 
that  occasioned  by  the  ingestion  of  opium,  as  to  have  actually  been  mistaken  for 
it;  and  is  as  true  an  instance  of  t  poisoning,'  as  if  urea  had  been  injected  into 
the  blood-vessels.  So,  in  the  asphyxia  which  is  produced  by  any  obstruction  to 
the  extrication  of  carbonic  acid  through  the  lungs,  the  subject  of  it  is  as  much 
'  poisoned,'  as  if  he  had  inhaled  carbonic  acid  from  without.  Again,  the  reten- 

1  This  is  shown  by  the  instances,  unhappily  of  no  unfrequent  occurrence,  in  which  the 
practitioners  who  have  unfortunately  become  the  vehicles  of  the  puerperal  poison,  and 
have  conveyed  it  to  several  p^^tients  in  succession,  have  experienced  the  same  direful  re- 
sults immediately  on  resumiug  obstetric  attendance,  after  a  lengthened  interval  of  suspen- 
sion from  it,  and  even  from  professional  employment  of  every  kind. 

2  See  Prof.   Simpson  '  On  the  Analogy  between  Puerperal  and  Surgical  Fever,*  in  tho 
"  Edinb.  Monthly  Journ."  vol.  xi.  p.  414;  and  vol.  xiii.  p.  72. 

3  It  is  well  known  to  Indian  Medical  Officers,  that  the  liability  to  Fever,  Dysentery, 
Cholera,  &c.  is  very  much  increased  during,  and  for  some  time  after,  a  severe  march.     For 
a  very  striking  example  of  the  influence  of  this  condition,  concurrently  with  overcrowding 
in  producing  a  terrible  augmentation  in  the  fatality  of  Cholera,  see  "Brit,  and  For.  Med.- 
Chir.  Rev.,"  vol.  ii.  pp.  80—90. 

*  For  a  fuller  exposition  of  this  doctrine,  see  the  "Brit,  and  For.  Med.-Chir.  Rev.," 
»ol.  xii.  p.  159,  et  seq. 


AND    ITS    KLLATION    TO    THE    LIVING    ORGANISM.          235 

tion  of  the  uric  acid,  biliary  matter,  lactic  acid,  and  other  substances  which  are 
normal  products  of  the  waste  or  disintegration  of  the  body,  is  capable  of  becom- 
ing a  source  of  morbid  action  in  the  system  generally ;  and  the  evil  is  of  course 
increased,  when  (as  frequently  happens)  augmented  production  is  concurrent 
with  imperfect  elimination.  But  perversions  of  the  ordinary  disintegrating  pro- 
cesses are  also  far  from  being  uncommon,  whereby,  instead  of  the  substances 
already  referred-to,  other  products  are  engendered,  whose  presence  in  the  circu- 
lating current  gives  rise  to  trains  of  symptoms  altogether  different.  Of  this 
class  we  seem  to  have  an  example  in  gout  and  rheumatism ;  the  materies  morbi 
of  which  diseases,  though  probably  not  identical  with  lithic  and  lactic  acids, 
would  seem  to  be  formed  from  the  decomposing  matters  which  might  normally 
have  generated  them.  There  can  be  no  doubt,  again,  that  many  chronic  diseases 
of  nutrition  are  attributable  to  a  similar  cause;  this  being  indicated  by  the  sym- 
metrical mode  in  which  they  affect  the  particular  parts  whose  condition  is  altered 
(§  217). 

228.  In  all  cases,  therefore,  one  of  the  first  questions  which  the  intelligent 
Practitioner  will  feel  called-upon  to  decide,  is,  whether  the  malady  he  has  to 
treat  originates  in  the  state  of  the  Blood,  or  in  a  disorder  purely  local ;  and,  if 
he  feel  justified  in  referring  it  to  the  blood,  whether  it  merely  depends  upon  an 
alteration  in  the  proportion  of  its  normal  constituents,  as  in  plethora  and  simple 
anaemia,  or  whether  its  phenomena  imply  the  presence  of  some  toxic  substance 
in  the  circulating  fluid.  —  If  the  former  be  his  conclusion,  he  has  then  to  en- 
deavour to  rectify  the  excess  or  the  deficiency,  by  reducing  the  former,  or  by  sup- 
plying the  latter ;  as  when  he  bleeds  and  prescribes  low  diet  for  Plethora,  and 
employs  iron  and  generous  living  in  Anaemia.     But  it  is  his  duty  to  take  care 
that  his  means  are  appropriate  to  his  ends;  and  especially  to  abstain,  when  en- 
deavouring to  draw-off  an  excess  of  one   constituent,  from  doing  serious  injury 
by  reducing  another  which  may  be  already  below  par,  and  of  which  the  presence 
may  be  essential  to  enable  the  system  to  resist  the  further  progress  of  the  malady. 
Thus,  as  we  have  seen,  blood-letting  lias  no  decided  effect  in  lowering  the  pro- 
portion of  jibrin  in  the  blood,  whilst  it  has  a  most  direct  influence  in  reducing 
the  number  of  red  corpuscles ;  and  there  can  be  little  doubt  that  the  too-copious 
venesection  which  was  formerly  practised  almost  indiscriminately  in  acute  in- 
flammations, had  a  pernicious  tendency  to  postpone  the  final  recovery  from  them, 
whilst  it  had  often  but  a  doubtful  efficacy  in  subduing  the  first  violence  of  the 
disease.     As  a  general  rule  it  may  be  stated,  that  general  blood-letting  is  likely 
to  be  rather  injurious  than  beneficial  in  toxic  inflammations,  in  which  the  vitality 
of  the  blood  as  a  whole  is  decidedly  lowered,  notwithstanding  the  large  increase 
in  the  proportion  of  fibrin ;  and  to  this  rule,  the  results  of  careful  and  extended 
observation  have  recently  shown  that  Rheumatism  is  seldom  to  be  considered  an 
exception,  notwithstanding  that  this  disease  was  formerly  considered  to  be  one  of 
those,  in  which  the  eflicacy  of  copious  depletion  was  most  undoubted.  —  In  dis- 
eases of  toxic  origin,  the  treatment  must  be  conducted  upon  principles  exactly 
the  same  as  those  by  which  the  practitioner  would  be  guided  in  his  treatment  of 
a  case  of  ordinary  poisoning ;  but  as  regards  the  two  classes  into  which  it  has 
been  shown  that  these  maladies  may  be  divided,  a  difference  must  be  made  in 
their  application. 

229.  The  '  morbid  poisons'  of  our  second  class  (§227)  are  distinguished  by 
this,  that  there  is  a  continual  new  generation  of  them  within  the  system ;  and  the 
first  indication  of  treatment,  therefore,  will  be  to  check  their  formation,  so  far  as 
this  may  be  possible.     This  is  the  rationale  of  the  dietetic  and  regiminal  treat- 
ment of  the  lithic,  lactic,  and  oxalic  diatheses,  of  lepra  and  psoriasis,  of  chronic 
pout  and  rheumatism,  and  many  other  chronic  diseases  of  toxic  origin.-— Secondly, 
w,e  should  endeavour  to  destroy  or  neutralize  the  poison,  if  we  have  any  remedies 
which  possess  such  an  action  upon  it.     Perhaps  the  curative  influence  of  arsenic 
in  some  of  the  chronic  skin-diseases,  is  one  of  the  best  examples  of  this  kind  j 


236          OF  THE  BLOOD;    ITS  VITAL   PROPERTIES, 

but  it  must  be  admitted  that  such  direct  '  antidotes '  to  morbid  poisons  are  very 
few  in  number. — Thirdly,  where  we  cannot  destroy  the  poison,  we  must  endeavour 
to  moderate  its  action  upon  the  system  ;  this  is  the  rationale  of  palliative  treat- 
ment of  every  description,  in  which  the  fans  et  oriyo  of  the  malady  is  left  un- 
changed.— But  fourthly,  our  main  object  must  be  to  eliminate  the  poison  from 
the  system  as  rapidly  as  possible,  by  the  various  channels  of  excretion ;  acting 
upon  these  by  remedies  which  either  increase  their  activity,  or  which  so  alter  the 
condition  of  the  morbific  matter,  as  to  enable  it  to  be  more  readily  drawn-off. 
The  judgment  of  the  well-informed  practitioner,  in  the  treatment  of  diseases  of 
this  class,  is  more  shown  in  his  discriminative  selection  of  the  best  means  of  thus 
aiding  the  Blood  to  regain  its  normal  purity,  than  in  any  more  apparently  t  heroic 
measures';  and  a  candid  review  of  the  most  approved  systems  of  treatment,  for 
diseases  of  the  type  here  alluded-to,  will  show  that  the  ratio  of  their  efficacy  is  in 
accordance  with  that  of  their  harmony  with  the  above  indications. 

230.  Among  the  Toxic  diseases  of  the  zymotic  class,  in  most  of  which  the 
poison  is  introduced  from  without,  the  course  of  the  morbid  phenomena  to  which 
this  gives-rise  is  usually  more  definite  and  specific,  and  its  duration  more  limited. 
There  is  no  source  within  the  body,  whence  a  new  supply  of  the  poison  is  con- 
tinually arising;  and  its  operation  ceases,  therefore,  as  soon  as  it  is  entirely 
eliminated  from  the  system.  But  there  is  this  peculiarity  in  the  action  of  many 
of  the  poisons  in  question,  that  they  have  the  power  of  multiplying  themselves 
within  the  body;  thus,  for  example,  when  small-pox  has  been  communicated  by 
the  inoculation  of  an  excessively  minute  portion  of  the  virus,  hundreds  and 
thousands  of  pustules  are  generated,  each  of  them  charged  with  a  poison  equally 
potent  with  that  from  which  they  originated.  It  is  to  this  multiplication,  that 
the  extension  of  zymotic  diseases,  by  communication  between  individuals  affected 
with  them  and  healthy  subjects,  is  chiefly  due ;  and  the  question  of  the  '  contagion  ' 
or  '  non-contagion '  of  any  particular  disease  of  this  class,  is,  therefore,  essentially 
that  of  multiplication  or  non-multiplication  of  the  poison  in  the  human  body. 
This  multiplication  of  certain  zymotic  poisons  is  a  yet  stronger  point  of  analogy 
to  the  action  of  f  ferments/  than  that  which  is  afforded  by  the  violence  of  the 
changes  they  induce,  when  compared  with  the  amount  in  operation.  Some  of 
these  poisons  are  of  such  potency,  that,  in  however  minute  a  quantity  they  are 
introduced,  they  will  change  the  whole  mass  of  the  blood  in  a  few  minutes;  and 
will  act  indiscriminately  on  all  individuals  alike ;  this  is  the  case,  for  example, 
with  the  venom  of  serpents.  On  the  other  hand,  there  are  many  (as  already 
remarked)  which  seem  to  require  the  presence  of  some  special  fermentable  matter 
in  the  blood  (§  226).  And  between  these  might  probably  be  established  a  regu- 
lar gradation, — from  those  most  f  pernicious '  forms  of  malarious  poison,  which 
derive  their  potency  from  the  intensity  of  vegetable  decomposition  under  the 
influence  of  a  high  temperature ;  or  those  (  malignant '  types  of  typhoid  poison, 
which  owe  their  special  intensity  to  animal  putrescence  engendered  by  filth  and 
overcrowding ;  both  of  these  attacking  a  very  large  proportion  of  those  who  are 
exposed  to  them, — to  those  milder  forms  of  zymotic  poisons,  which,  though 
derived  from  the  same  sources  with  the  preceding  act  with  so  much  less  of  uni- 
formity upon  different  individuals,  that  we  can  scarcely  fail  to  recognise,  as  a 
'  predisposing  cause/  or  rather  as  a  necessary  concurrent  condition,  the  presence 
of  some  readily-decomposable  matter  in  the  blood.  The  long-continued  action 
of  these  poisons,  in  their  milder  forms,  seems  itself  capable  of  inducing  this  con- 
dition; thus,  a  healthy  person  who  settles  in  an  aguish  country,  may  remain  free 
from  intermittent  fever  for  a  considerable  time,  but  his  health  gradually  deterior- 
ates, and  at  last  he  becomes  the  subject  of  the  disease,  which  would  have  much 
earlier  attacked  him,  if  his  blood  had  been  brought  into  the  *  fermentable'  state 
by  irregularity  of  diet,  over-exertion,  &c.;  and  the  same  may  be  observed  in  the 
case  of  those  long  exposed  to  the  poison  of  typhoid  or  other  fevers,  which  specially 
locates  itself  in  animal  miasmata,  if  it  be  not  actually  engendered  by  them. 


AND    ITS     RELATION    TO    THE    LIVING     ORGANISM.      237 

231.   In  some  of  the  diseases  of  this  class,  the  change  in  the  qualities  of  the 
Blood  produced  by  the  introduction  of  the  poison,  is  such  as  to  give  it  a  morbid 
action  on  certain  organs  or  tissues  only  ;  their  phenomena  in  this  respect  correspond- 
ing with  those  of  ordinary  poisons,  and  of  the  toxic  diseases  previously  noticed. 
Such  may  be  said  of  vaccinia,  gonorrhoea,  primary  syphilis,  &c.,  in  which  the 
general  functions  of  the  body  seem  to  be  disturbed  chiefly  or  solely  through  the 
local  disorder.     It  may  happen  that,  even  where  a  specific  poison  is  present  in  the 
blood,  it  may  not  be  potent  enough  to  manifest  itself  in  any  disordered  action, 
either  general  or  local,  until  the  depressed  state  of  the  nutrition  of  some  part  or 
organ  renders  it  more  susceptible  of  a  further  perversion  ;  thus  it  is  very  common 
for  the  first  developnient  of  Cancer  to  follow  upon  some  local  injury;  and  where 
constitutional  Syphilis  may  be  presumed  to  exist,  it  often  seems  to  lie  dormant, 
until  some  appropriate  part  is  rendered,  by  some  such  cause,  peculiarly  susceptible 
to  this  malady.1 — But,  in  other  cases,  we  find  that  the  contamination  of  the  blood 
is  such  as  primarily  to  produce  more  or  less  disturbance  in  all  the  functions ;  as 
we  especially  witness  in  the  severer  forms  of  fever,  in  poisoning  by  venomous 
serpents,  &c.     Even  in  this  last  class  of  cases,  however,  a  special  determination 
to  one  organ  or  system  is  frequently  obvious;  and  this  may  be  so  constant  as  to 
be  characteristic  of   the  disease,  as  is  the  case  with   the  skin-affection  in  the 
Exanthemata  generally,  the  affection  of  the  throat  and  the  kidneys  in  Scarlatina, 
and  that  of  the  air-passages  in  Measles.     But  in  other  instances,  the  local  affec- 
tions produced  in  different  individuals  by  the  same  specific  poison,  vary  in  their 
relative  intensity,  and  even  in  their  seat,  according  to  the  previous  conditions 
which  their  respective  subjects  afford;  and  whilst,  in  some  instances,  this  ^aria- 
tion  may  be  clearly  traced  to  local  peculiarities  of  nutrition,  in  others  it  seems 
only  capable  of  being  accounted-for  by  supposing  that  the.  blood  of  each  indi- 
vidual has  some  peculiar  or  personal  character,  which  causes  it  to  be  differently 
affected  in  each  subject.     Of  the  determining  influence  of  local  deteriorations  of 
nutrition,  we  occasionally  meet  with  curious  examples  in  the  Exanthemata;  thus, 
the  eruption  of  Measles  has  been  seen  to  be  deepest  and  most  diffused  over  a 
knee  affected  with  chronic  synovial  inflammation  and  general  swelling;  and  in 
a  patient  who  became  affected  with  Small-Pox  soon  after  a  fall  on  the  nates,  the 
pustules,  though  thinly  scattered  elsewhere,  were  crowded-together  on  the  injured 
part  as  thickly  as  possible  (Paget.  op.  cit.,  p.  444).     So,  during  an  epidemic  Influ- 
enza, it  is  evident  that  the  local  affection  often  manifests  itself  chiefly  (if  not  solely) 
in  what  was  previously  regarded  as  the  '  weak  point '  of  each  patient's  system. 
Of  those  variations  on  the  other  hand,  which,  as  they  cannot  be  thus  attributed 
to  purely-local  causes,  must  be  referred  to  peculiarities  in  the  general  state  of  the 
system,  and  especially  of  the  blood,  of  each  individual,  we  have  a  highly  charac- 
teristic example  in  the  following  incident,  which  fell   under  the  notice  of  the 
Author's  friend,  Mr.  Huxley,  at  that  time  assistant-surgeon  on  board  her  H.M.S. 
Rattlesnake,  which  had  been  engaged  on  a  surveying  voyage  about  New  Guinea 
and  Australia.     The  crew  seem  to  have  acquired  a  predisposition  to  disease  by 
long  confinement,  exposure  to  tropical  sunshine,  unwholesome  food,  and  other 
unfavourable  influences ;  but  no  decided  malady  had  shown  itself  among  them, 
until  one  of  them,  after  slightly  wounding  his  hand  with  a  beef-bone,  had  sup- 
puration of  the  axillary  lymphatic  glands,  with  which  typhoid  symptoms  and 
delirium  were  associated,  and  which  proved  fatal.     A  few  days  after  his  death, 
the  sailor  who  washed  his  clothes  had  similar  symptoms  of  disease  in  the  axilla ; 
and  for  four  or  five  months,  he  suffered  with  sloughings  of  portions  of  the  cellular 
tissue  of  the  axilla,  arm,  and  trunk  of  the  same  side.     Near  the  same  time,  a 
third  sailor  had  diffuse  inflammation  and  sloughing  in  the  axilla;  and  after  this, 
the  disease  ran  in  various  forms  through  the  ship's  company,  between  thirty  and 
forty  of  whom  were  sometimes  on  the  sick  list  at  once.     Some  had  diffuse  cellular 
inflammation ;  some  had  inflammation  of  the  lymphatic  glands  of  the  head,  axilla. 
1  See  Mr.  Paget's  "  Lectures  on  Surgical  Pathology,"  p.  309,  Am.  Ed. 


238    ON  THE  VITAL  PROPERTIES  OF  THE  BLOOD. 

and  lower  extremities;  one  had  severe  idiopathic  erysipelas  of  the  head  and 
neck;  another  had  phlegmonous  erysipelas  of  the  hand  and  arm  after  an  acci- 
dental wound;  others  had  low  fever  with  or  without  enlargement  of  glands. 
Finally,  the  disease  took  the  form  of  mumps,  which  affected  almost  everybody  on 
board.  The  epidemic  lasted  from  May  to  July  (the  winter  in  the  southern 
hemisphere),  the  ship  being  at  sea  during  the  whole  time. — The  local  determina- 
tion of  a  morbid  poison  may  frequently  be  regarded  as  one  of  the  means  whereby 
the  blood  and  the  system  at  large  are  freed  from  its  action.  Of  this,  again,  we 
have  a  most  characteristic  example  in  the  Exanthemata :  for  it  is  a  matter  of 
constant  observation,  that  the  constitutional  symptoms,  especially  fever  and 
delirium,  are  most  severe  before  the  cutaneous  eruption  comes-out;  that  there  is 
much  greater  danger  to  life,  when  the  eruption  does  not  develope  itself  fully ;  and 
that  its  premature  repression  induces  a  return  of  the  severer  constitutional  affec- 
tion.1 So  in  Syphilis  and  Cancer  (as  Mr.  Paget  remarks),  the  severest  defects  or 
disturbances  in  the  whole  economy  may  coexist  with  the  smallest  amounts  of 
specific  local  disease;  and  it  has  been  laid-down  as  a  general  law  by  Dr.  Robert 
Williams,  "  that  when  a  morbid  poison  acts  with  its  greatest  intensity,  and  pro- 
duces its  severest  forms  of  disease,  fewer  traces  of  organic  alterations  of  structure 
will  be  found,  than  when  the  disease  has  been  of  a  milder  character."2 

232.  In  nearly  all  the  Toxic  diseases  of  the  zymotic  class,  there  is  a  natural 
tendency  to  the  self-elimination  of  the  poison  and  of  the  products  of  its  action 
on  the  blood,  either  by  the  operation  of  the  ordinary  excretory  organs,  or  by  the 
peculiar  local  actions  just  adverted-to;  and  this  process  takes  place  in  many 
instances  with  such  regularity,  that  not  only  the  period  which  it  will  altogether 
require,  but  each  of  those  successive  epochs  which  mark  the  stages  of  develop- 
ment and  metamorphosis  in  the  poison  and  in  the  products  of  its  action,  may  be 
almost  exactly  predicted.  There  is  not,  in  fact,  a  more  remarkable  indication  of 
the  '  Life  of  the  Blood/  than  is  afforded  by  its  extraordinary  power  of  self-re- 
covery, after  having  undergone  the  excessive  perversion  which  is  consequent 
upon  the  introduction  of  the  more  potent  Zymotic  poisons;  and  every  philosophi- 
cal physician  is  ready  to  admit,  that  it  is  to  this  '  vis  medicatrix  naturae/  rather 
than  to  any  remedial  agency  which  it  is  in  his  power  to  apply,  that  he  must  look 
for  the  restoration  of  his  patient.  The  very  nature  of  the  action  of  zymotic 
poisons  upon  the  blood,  seems  to  forbid  the  expectation  of  our  being  able  to 
neutralize  or  check  that  action  by  antidotes;  and  the  objects  of  treatment  wholly 
lie,  therefore,  in  promoting  the  elimination  of  the  morbific  matters  thus  en- 
gendered, in  keeping-under  any  dangerous  excess  of  local  action,  and  in  sup- 
porting the  system  during  the  continuance  of  the  malady.  In  a  large  proportion 
of  zymotic  diseases,  it  is  probable  that  the  oxidation  of  the  morbific  matter  by 
the  aeration  of  the  blood,  is  the  chief  means  of  its  removal ;  and  it  is  accordant 
with  this  view,  that  the  encouragement  of  the  respiratory  function,  both  pul- 
monary and  cutaneous,  by  a  pure  and  cool  atmosphere,  and  by  keeping  the  skin 
moist  (either  by  the  administration  of  diaphoretic  medicines,  or  by  external  ap- 
plications), should  be  found  one  of  the  most  efficient  means  of  promoting  re- 
covery.3 Whilst  mild  purgatives  may  be  employed  with  advantage  for  the  same 

*  It  may  be  objected  to  this  general  statement,  that  as  the  severity  of  Small-Pox  usually 
bears  a  constant  ratio  to  the  amount  of  the  cutaneous  eruption,  this  cannot  be  regarded  as 
relieving  the  blood  of  a  poisonous  impregnation :  but  it  is  to  be  borne  in  mind,  on  the  one 
hand,  that  the  confluence  of  the  pustules  greatly  impedes  the  normal  functions  of  the  skin, 
whereby  the  constitutional  disturbance  is  most  seriously  aggravated ;  their  suspension,  if 
complete,  being  itself  adequate  to  destroy  life ;  and  besides  this,  the  excessive  severity  of 
the  eruption  is  an  indication  that  the  poison  has  either  possessed  an  extraordinary  potency, 
or  has  found  within  the  blood  a  material  peculiarly  favorable  for  its  development 

3  "  Elements  of  Medicine,"  vol.  i.  p.  12. 

3  Dr.  Daniell,  whose  long  familiarity  with  the  most  pernicious  forms  of  African  fever, 
and  with  the  various  modes  of  treatment  which  have  been  put  in  practice  for  its  cure, 
a  most  decided  preference  to  the  sudorific  system  in  vogue  among  the  natives,  as 


•  OF  THE  CIRCULATION  OF  THE  BLOOD.       239 

end,  in  the  earlier  stages  of  these  diseases,  care  must  be  taken  that  the  system  be 
not  too  much  debilitated  by  their  action ;  and  the  same  caution  must  be  observed 
with  regard  to  the  use  of  local  depletion  or  counter-irritation,  for  the  purpose  of 
subduing  the  violence  of  some  local  affection.  In  fact,  the  general  tendency  of 
these  diseases  to  the  adynamic  type,  seems  to  indicate  that,  however  beneficial 
the  immediate  results  of  reducing  treatment  may  appear  to  be,  its  remote  effects 
are  much  to  be  dreaded.  And  when  the  results  of  a  large  and  varied  experience 
are  brought  together,  the  Author  believes  that  those  will  be  found  most  satis- 
factory, in  which  the  treatment  has  been  moderately  evacuant,  and  early  susten- 
tative.1 


CHAPTER  VI. 

OP   THE   CIRCULATION   OP   THE  BLOOD. 
1. — Of  the  Circulation  in  General 

233.  THE  Circulation  of  nutritive  fluid  through  the  body  has  for  its  object, 
on  the  one  part,  to  convey  to  every  portion  of  the  organism  the  materials  for  its 
growth  and  renovation,  together  with  the  supply  of  Oxygen  which  is  requisite 
for  its  vital  actions,  (especially  for  those  of  the  Nervo-Muscular  apparatus) ;  and 
at  the  same  time  to  carry-off  the  particles  which  are  set-free  by  the  disintegration 
or  'waste'  of  the  tissues,  and  which  are  to  be  removed  from  the  body  by  the 
Excreting  processes.  Of  these  processes,  the  one  most  constantly  in  operation, 
as  well  as  most  necessary  for  the  maintenance  of  the  purity  of  the  blood,  is  the 
extrication  of  Carbonic  acid,  through  the  Respiratory  organs ;  and  this  is  made 
subservient  to  the  introduction  of  Oxygen  into  the  system.  In  Man,  as  in  other 
Vertebrated  animals,  there  is  a  regular  and  continuous  movement  of  the  nutritive 
fluid  through  the  sanguiferous  vessels ;  and  upon  the  maintenance  of  this,  the 
activity  of  all  parts  of  the  organism  is  dependent.  In  common  with  Birds  and 
Mammals,  again,  Man  has  a  Respiratory  circulation  entirely  distinct  from  the 
Systemic ;  all  the  blood  which  has  returned  from  the  body  being  transmitted  to 
the  lungs,  and  being  brought  back  to  the  heart  again,  before  it  is  again  sent- 
forth  for  the  nourishment  of  the  tissues  and  for  the  maintenance  of  their  func- 
tional activity.  The  Heart  is  placed  at  the  junction  of  these  two  distinct  circu- 
lations, which  may  be  likened  to  the  figure  8 ;  and  it  may  be  said  to  be  formed 
by  the  fusion  of  two  distinct  organs,  a  '  pulmonary'  and  a  '  systemic'  hearty  for 
its  right  and  left  sides,  which  are  respectively  appropriated  to  these  purposes, 
have  no  direct  communication  with  each  other  (in  the  perfect  adult  condition,  at 
least),  and  seem  merely  brought-together  for  economy  of  material.2  Each  system 
has  its  own  set  of  Arteries  or  efferent  vessels,  and  of  Veins  or  afferent  trunks  ; 
these  communicate  at  their  central  extremity  by  the  Heart,  and  at  their  peripheral 
extremity  by  the  Capillary  vessels,  which  are  nothing  else  than  the  minutest 
ramifications  of  the  two  systems,  inosculating  into  a  plexus.  —  Besides  the  sys- 

having  a  vast  superiority  over  the  venesections,  saline  purgatives,  and  large  doses  of 
calomel,  which  most  European  practitioners  have  employed.  See  his  "  Sketches  of  the 
Medical  Topography  and  Native  Diseases  of  the  Gulf  of  Guinea,"  p.  120. 

1  On  the  subject  of  the  latter  portion  of  this  section,  see  the  treatise  of  Dr.  Robert  TVil 
Hams  on  "  Morbid  Poisons,"  the  "Principles  of  Medicine"  of  Dr.  Charles  J.  B.  Williams* 
the  "  Lectures  on  General  Pathology"  by  Mr.  Simon,  and  the  chapter  on  '  Specific  Diseases' 
in  Mr.  Paget's  "  Lectures  on  Surgical  Pathology." 

a  At  an  early  period  of  foetal  life,  as  in  the  permanent  state  of  the  Dugong,  the  heart  ?s 
so  deeply  cleft,  from  the  apex  towards  the  base,  as  almost  to  give  the  idea  of  two  separate 
organs. 


240        OF  THE  CIRCULATION  OF  THE  BLOOD. 

temic  and  pulmonary  circulations,  however,  there  is  another  which  is  no  less  dis- 
tinct, although  it  has  not  an  impelling  organ  of  its  own.  This  is  the  '  portal' 
circulation,  which  is  interposed  between  the  venous  trunks  of  the  abdominal  vis- 
cera and  the  Vena  Oava,  for  the  purpose  of  distributing  that  blood  through  the 
Liver,  in  which  organ  its  newly-absorbed  materials  undergo  assimilation  (§  132), 
whilst  its  excrementitious  matters  are  separated  by  the  secreting  process.  The 
Vena  Portae,  which  is  formed  by  the  convergence  of  the  gastric,  intestinal, 
splenic,  and  pancreatic  veins,  subdivides  again  like  an  artery,  so  as  to  form  a 
capillary  plexus  which  extends  through  the  whole  substance  of  the  liver;  and 
the  Hepatic  vein,  collecting  the  blood  from  this  plexus,  conveys  it  into  the  Vena 
Cava.  Thus  the  portal  circulation  is  grafted  (so  to  speak)  upon  the  general  cir- 
culation, in  precisely  the  same  mode  as  the  respiratory  circulation  is  grafted  upon 
it  in  Mollusca  and  Crustacea;  and  if  the  '  sinus'  of  the  vena  portae  had  possessed 
contractile  muscular  walls,  it  would  have  ranked  as  the  proper  heart  of  the  portal 
system.  The  really  arterial  character  of  the  Vena  Portse  is  well  shown  by  com- 
paring it  with  the  Aorta  of  Fishes;  which  is  formed  by  the  convergence  of  the 
branchial  veins,  and  then  distributes  the  blood  which  it  has  received  from  them 
to  the  body  generally. 

234.  That  the  movement  of  the  Blood  through  the  arterial  trunks  and  the 
capillary  tubes,  is,  in  Man,  and  in  other  warm-blooded  animals,  chiefly  dependent 
upon  the  action  of  the  Heart,  there  can  be  no  doubt  whatever.  It  can  be  easily 
shown  by  experiment,  that  if  the  arterial  current  be  checked,  the  capillaries  will 
immediately  cease  almost  entirely  to  deliver  the  blood  into  the  veins,  and  the 
venous  circulation  will  be  consequently  arrested.  And  it  has  also  been  proved, 
that  the  usual  force  of  the  Heart  is  sufficient  to  propel  the  blood,  not  only  through 
the  arterial  tubes,  but  through  the  capillaries,  into  the  veins ;  since  even  a  less 
force  will  serve  to  propel  warm  water  through  the  vessels  of  an  animal  recently 
dead.1  But  there  are  certain  "  residual  phenomena"  even  in  Man,  which  clearly 
indicate  that  this  is  not  the  whole  truth ;  for  not  only  is  the  general  current  of 
blood  greatly  modified  in  its  passage  through  the  circulating  system,  but  there 
are  many  variations  in  its  movement,  which,  being  very  limited  in  their  extent, 
cannot  be  attributed  to  any  central  disturbance,  and  must  therefore  be  dependent 
on  causes  purely  local.  Hence  we  are  led  to  perceive  that  forces  existing  in  the 
Blood-vessels  themselves  must  have  a  considerable  influence,  in  producing  both 
general  and  local  modifications  of  the  effects  of  the  Heart's  action.  There  are 
also  indications  of  the  existence  of  influences  in  which  the  blood-vessels  do  not 
partake,  arising  from  those  changes  occurring  between  the  blood  and  the  tissues, 
that  constitute  the  processes  of  Nutrition,  Secretion,  &c.  Of  the  nature  of  these 
influences,  and  of  the  degree  of  their  operation,  the  most  correct  idea  may  be 
obtained  by  examining  the  phenomena  of  the  Circulation  in  those  beings,  in 
which  the  moving  power  is  less  concentrated  than  it  is  in  the  higher  Animals. 
Thus  we  find  that  in  Plants  and  the  lowest  Animals,  as  in  the  earliest  embryonic 
state  of  the  highest,  a  movement  of  nutritious  fluid  takes  place  through  a  system 
of  minute  passages  or  channels  excavated  in  the  tissues  (representing  a  capillary 
plexus),  without  any  vis  a  tergo  derived  from  an  impelling  organ.  Ascending  a 
little  higher  in  the  series,  we  meet  with  a  system  of  vascular  trunks,  distributing 
the  blood  to  these  plexuses,  and  collecting  it  again  from  them ;  and  the  walls  of 
these  trunks  are  so  far  endowed  with  contractility,  as  to  assist,  by  a  sort  of 
peristaltic  movement,  in  the  maintenance  of  the  current  through  them.  Still 
passing  upwards,  we  find  this  contractility  manifesting  itself  especially  in  some 
limited  portion  or  portions  of  the  vascular  system,  which  execute  regular  move- 
ments of  contraction  and  dilatation ;  and  this  tendency  to  concentration  is  in- 
creasingly observed,  until  the  whole  movement  is  subordinated  to  the  action  of  a 
principal  propelling  organ,  the  Heart.2 — We  shall  now  examine  what  agency  in 

.    l  See  Dr.  Williams's  "  Principles  of  Medicine,"  3d  Am.  Ed.,  p.  154,  note. 
*  See  "  Princ.  of  Comp.  Phys.,"  chap.  v.  Am.  Ed. 


ACTION     OF    THE    HEART.  241 

the  Human  Circulation  may  be  attributed  to  the  Heart,  the  Arteries,  and  the 
Veins  respectively ;  and  what  other  forces  may  be  fairly  presumed  to  operate  in 
the  Capillary  circulation. 

2. — Action  of  the  Heart. 

235.  The  Heart  is  endowed  in  an  eminent  degree  with  the  property  of  irri- 
tability ;  by  which  is  meant,  the  capability  of  being  easily  excited  to  movements 
of  contraction  alternating  with  relaxation.  Thus,  after  the  Heart  has  been 
removed  from  the  body,  and  has  ceased  to  contract,  a  slight  irritation  will  cause 
it  to  execute,  not  one  movement  only,  but  a  series  of  alternate  contractions  and 
dilatations,  gradually  diminishing  in  vigour  until  they  cease.  The  contraction 
begins  in  the  part  irritated,  and  then  extends  to  the  rest.  It  appears,  however, 
from  Mr.  Paget's  experiments,1  that  it  is  necessary  for  the  propagation  of  this 
irritation,  that  the  parts  should  be  connected  by  muscular  tissue,  of  which  a  very 
narrow  isthmus  will  suffice ;  and  that  the  propagation  will  not  take  place,  if  the 
connecting  isthmus  be  composed  of  tendon,  even  though  this  be  a  portion  of  the 
auriculo-ventricular  ring,  which  has  been  supposed  by  some  to  be  peculiarly  effi- 
cacious in  this  conduction.  —  That  the  irritability  of  the  Heart  is  not  dependent 
upon  the  Cerebro-spinal  system,  appears  not  merely  from  the  manifestation  of  it 
when  the  organ  is  altogether  removed  from  the  body ;  but  also  from  the  fact, 
that  if  the  flow  of  blood  through  the  lungs  be  kept-up  by  artificial  respiration, 
the  heart's  action  will  continue  for  a  lengthened  period,  even  after  the  Brain  and 
Spinal  Cord  have  been  removed,  and  when  animal  life  is,  therefore,  completely 
extinct.  Hence  we  see  that  the  Irritability  of  this  organ  must  be  an  endowment 
properly  belonging  to  itself,  and  not  derived  from  that  portion  of  the  Nervous 
System  (§  238).  Like  the  contractility  of  other  muscles,  it  can  only  be  con- 
tinuously sustained  by  a  supply  of  Arterial  blood  to  its  own  tissue  (See  PRINC. 
OF  GEN.  PHYS).  It  is  much  less  speedily  lost  in  cold-blooded  animals,  however, 
than  in  warm-blooded ;  the  heart  of  the  Frog,  for  example,  will  go  on  pulsating 
for  many  hours  after  its  removal  from  the  body  j  and  it  is  stated  by  Dr.  Mitchell,2 
that  the  heart  of  a  Sturgeon,  which  he  had  inflated  with  air,  continued  to  beat, 
until  the  auricle  had  absolutely  become  so  dry,  as  to  rustle  during  its  movements. 
It  has  further  been  shown  by  Mr.  Tod,  that  the  irritability  of  the  heart  is  of 
great  duration  after  death  in  very  young  animals;  which,  as  was  long  since 
demonstrated  by  Dr.  Edwards,  agree  with  the  cold-blooded  Vertebrata  in  their 
power  of  sustaining  life,  for  a  lengthened  period,  without  oxygen. 

286.  It  is  difficult  to  account  for  the  long  continuance  of  the  alternate  con- 
tractions and  relaxations  of  the  muscular  parietes  of  the  Heart,  after  all  evident 
stimuli  have  ceased  to  act  upon  it ;  and  many  theories  have  been  offered  on  the 
subject,  none  of  which  afford  an  adequate  explanation.  The  extraordinary  ten- 
dency to  rylithmical  action,  by  which  the  heart  is  distinguished  from  nearly  all 
other  muscles,  is  shown  by  the  fact,  that  not  only  do  the  entire  hearts  of  cold- 
blooded animals  continue  to  act  long  after  their  removal  from  the  body,  but  even 
separated  portions  of  them  will  contract  and  relax  with  great  regularity  for  a 
long  time.  Thus  the  auricles  will  persist  in  their  rhythmical  action,  when  cut- 
off above  the  auriculo-ventriculo  rings ;  and  the  apex  of  the  heart  will  do  the 
same,  when  separated  from  the  rest  of  the  ventricle.  The  stimulus  of  the  con- 
tact of  blood  with  the  lining  membrane  of  the  heart,  to  which  its  regular  actions 
have  been  commonly  referred,  can  have  no  influence  in  producing  such  move- 
ments ;  nor  does  it  appear  that  the  contact  of  air  can  take  its  place ;  since,  as 
Dr.  J.  Reid  has  shown,  the  ryhthmical  contractions  of  the  heart  of  a  frog  will 

1  "  Brit,  and  For.  Med.  Keview,"  vol.  xxi.  p.  551. 

9  "American  Journal  of  the  Medical  Sciences,"  vol.  vii.  D.  58;  see  also  Prof.  Dungli 
ion's  "  Human  Physiology,"  7th  edit.,  vol.  ii.  p.  149. 

16 


242  OF    THE    CIRCULATION    OF    THE    BLOOD. 

continue  in  vacuo.}  Nor  is  there  any  evidence  that  the  flow  of  blood  through 
the  cavities  has  the  effect  of  securing  the  regularity  of  their  successive  contrac- 
tions in  the  living  body  ;  for  this  regularity  is  equally  marked  in  the  contractions 
of  the  excised  heart,  when  perfectly  emptied  of  blood,  so  long  as  its  movements 
continue  vigorous.  But  when  its  irritability  is  nearly  exhausted,  the  usual 
rhythm  is  often  a  good  deal  disturbed,  so  that  the  contractions  of  auricles  and 
ventricles  do  not  regularly  alternate  with  each  other;  and  one  set  frequently 
ceases  before  the  other. 

237.  The  difficulty  of  finding  any  other  satisfactory  solution  of  the  problem, 
has  recently  led  many  Physiologists  to  recur  to  the  idea,  that  the  Heart's  action 
is  dependent  upon  Nervous  power;  this  power  being  supposed  to  be  derived, 
however,  not  from  the  Cerebro-spinal  system,  but  from  the  ganglia  of  the  Sym- 
pathetic system  which  are  found  in  the  organ  itself.     For  the  proper  estimation 
of  the  evidence  favourable  to  this  view,  it  is  requisite  that  we  should  bring-toge- 
ther the  principal  facts  which  indicate  the  relation  of  the  Heart's  action  to  Ner- 
vous influence,  from  whatever  source  this  may  proceed. 

238.  .It  was  formerly  supposed,  that  the  movements  of  the  Heart  were  depend- 
ent upon  its  connection  with  the  centres  of  the  Cerebro-spinal  nervous  system : 
and  the  experiments  of  Legallois  and  others,  who  found  that  they  were  arrested 
by  crushing,  or  otherwise  suddenly  destroying  large  portions  of  these  centres, 
appeared  to  favour  the  supposition.     But  it  has   been  shown  by  Dr.  Wilson 
Philip  and  his  successors  in  the  same  inquiry,  that  the  whole  Cerebro-Spinal  axis 
might  be  gradually  removed  without  any  such  consequence ;  which  fact  harmo- 
nizes perfectly  with  the  "  experiments  prepared  for  us  by  Nature, "  in  the  pro- 
duction of  monsters  destitute  of  these  centres,  which  nevertheless  possess  a  regu- 
larly-pulsating heart.     Still  the  fact  of  every-day  occurrence,  that  sudden  and 
severe  injuries  of  the  Cerebro-spinal  system  of  nerves  have  power  to  weaken,  or 
even  to  check  the  Heart's  action,  is  one  which  unmistakeably  indicates  the  in- 
fluence which  this  exerts  over  the  central  organ  of  the  circulation.     We  witness 
this,  not  only  in  the  effects  of  concussion  of  the  Brain,  or  severe  injury  of  the 
Spinal  Cord,  but  also  in  the  depressing  result  of  lesions  which  affect  any  large 
part  of  the  peripheral  expansion  of  the  nerve-trunks.     Thus  a  dangerous  reduc- 
tion in  the  force  and  frequency  of  the  Heart's  contractions,  constituting  the  most 
important  manifestation  of  what  is  known  as  Shock,  may  be  produced  by  the 
crushing  of  a  portion  of  a  limb  (especially  of  a  joint),  by  an  extensive  burn  of 
any  part  of  the  surface  (particularly  in  children,  whose  nervous  system  is  more 
susceptible  of  such  impressions  than  that  of  adults2),  by  the  rupture  or  perfora- 
tion of  some  important  viscus  (such  as  the  lung,  stomach,  intestinal   canal, 
bladder,  or  uterus),  or  by  the  destruction  of  its  tissue  by  chemical  agents  (as  in 
cases  of  corrosive  poisoning).     It  is  obviously  in  the  Cerebro-Spinal  centres,  too, 
that  the  influence  must  originate,  which  is  exerted  by  excessive  Mental  Emotions, 

1  "  Cyclopaedia  of  Anatomy  and  Physiology,"  vol.  ii.  p.  611.  —  This  experiment  has 
been  since  repeated  by  Prof.  Tiedemann  ("  Miiller's  Archiv.,"  1847)  and  by  Drs.  Mitchell 
and  Bache  (Prof.  Dunglison's  "Human  Physiology,"  7th  Edit.,  vol.  ii.  p.  150)  with  a 
different  result ;  the  pulsations  being  speedily  brought  to  a  stand  by  the  exhaustion  of 
the  air,  and  being  renewed  when  it  was  re-admitted.  This,  however,  does  not  invalidate 
the  positive  fact,  that  the  pulsation  may  continue  in  vacuo,  which  proves  that  the  stimulus 
of  air  cannot  be  its  maintaining  power :  and  only  shows  that  the  presence  of  oxygen  is 
essential  to  the  continuance  of  the  heart's  movements,  as  to  muscular  action  in  general. 

a  The  large  quantity  of  stimulus  which  can  be  borne  even  by  children,  suffering  under 
severe  burns,  is  very  extraordinary.  There  can  be  no  doubt  that  many  lives  have  been 
saved  by  the  judicious  administration  of  them,  to  an  amount  which  would  have  been  d 
priori  judged  in  itself  fatal;  but  that  many  more  have  been  sacrificed  to  neglect,  even  on 
the  part  of  those  whose  duty  it  is  to  watch  the  indications  with  the  closest  attention.  The 
Author's  observations  lead  him  to  believe,  that  Hospital  Nurses  very  commonly  make-up 
their  minds,  that  children  who  have  met-with  severe  burns  must  die;  and  that,  unless 
closely  watched,  they  do  not  take  the  trouble  to  use  those  means  of  which  Science  and 
Experience  alike  dictate  the  free  employment. 


ACTION    OF    THE    HEART.  243 

in  depressing  or  even  checking  the  Heart's  action,  and  in  hence  producing  a 
state  of  the  general  system  closely  resembling  that  which  results  from  severe 
bodily  injury. 

239.  It  has  been  asserted  by  Valentin  and  other  experimenters  (though  many 
more  have  obtained  none  but  negative  results),  that  mechanical  irritation  of  the 
Pneumogastric  nerves,  especially  at  their  roots,  has  a  tendency  to  accelerate  the 
heart's  action,  or  to  re-excite  it  when  it  has  come  to  a  stand.  On  the  other  hand, 
it  is  certain  that  these  nerves  may  serve  as  the  channel  of  an  influence  of  a  very 
opposite  character;  for  the  experiments  of  MM.  Weber,  which  have  been  re- 
peated by  many  others  with  the  same  effect,  have  shown  that  the  movements  of 
the  Heart  may  be  immediately  arrested  by  the  transmission  of  the  electric  cur- 
rent from  a  rotating  magnet,  either  through  the  Spinal  Cord,  or  through  the 
Pneumogastrics  divided  at  their  origin ;  the  same  irritation,  however,  applied  to 
a  single  one  of  the  Vagi,  produced  no  effect.1  Hence  it  is  probable  that  the  in* 
fluence  of  sudden  and  violent  injury  to  the  Cerebro-spinal  system,  may  be  con- 
veyed through  these  trunks,  as  well  as  through  the  Sympathetic  nerves. — Admit- 
ting, then,  that  some  influence  is  exerted  upon  the  Heart's  action  by  the  Cardiac 
branches  of  the  Pneumogastric,  it  remains  to  inquire  whether  that  influence  be 
essential  to  its  movements;  and  whether  these  nerves  form  the  channel  through 
which  they  are  affected  by  emotions  of  the  mind,  or  by  conditions  of  the  bodily 
system.  In  regard  to  the  first  point,  no  doubt  can  be  entertained ;  since  the 
regular  movements  of  the  heart  are  but  little  affected  by  section  of  the  Pneumo- 
gastrics. With  respect  to  the  second,  there  is  more  difficulty  ;  since  the  number 
of  causes  which  may  influence  the  rapidity  and  pulsations  of  the  heart,  is  very 
considerable.  For  example,  when  the  blood  is  forced-on  more  rapidly  towards 
the  heart,  as  in  exercise,  struggling,  &c.,  its  contractions  are  rendered  more 
frequent;  and  when  the  current  moves-on  more  slowly,  as  in  a  state  of  rest,  their 
frequency  becomes  proportionably  diminished.  If  the  contractions  of  the  heart 
were  not  thus  in  some  degree  dependent  upon  the  blood,  and  their  number  were 
•not  regulated  by  the  quantity  flowing  into  its  cavities,  very  serious  and  inevitably- 
fatal  disturbances  of  the  heart's  action  would  soon  result.  That  this  adjustment 
takes  place  otherwise  than  through  the  medium  of  the  nervous  centres,  is  evident 
from  the  fact,  that,  in  a  dog,  in  which  the  Pneumogastric  and  Sympathetic  had 
been  divided  in  the  neck  on  each  side,  violent  struggling,  induced  by  alarm, 
raised  the  number  of  pulsations  from  130  to  260  per  minute.2  It  is  difficult  to 
ascertain,  by  experiments  upon  the  lower  animals,  whether  simple  emotion,  un- 
attended with  struggling  or  other  exertion,  would  affect  the  pulsation  of  the 
heart,  after  section  of  the  Pneumogastrics;  but  when  the  large  proportion  of  the 
Sympathetic  nerves  proceeding  to  this  organ  is  considered,  and  when  it  is  also 
remembered  that  irritation  of  the  roots  of  the  upper  cervical  nerves  stimulates 
the  action  of  the  heart  through  these,  we  can  scarcely  doubt  that  both  may  serve 
as  the  channels  of  this  influence,  especially  in  such  animals  as  the  dog,  in  which 
the  two  freely  inosculate  in  the  neck.3 

1  "Archives  d'Anat.  G6n&r.,  et  de  Physiol.,"  Jan.  1846;  and  "Wagner's  Handwortei- 
buch,"  band  iii.  abth.  2,  Art.  "  Muskelbewegung." 

2  See  Dr.  J.  Reid's  "  Anat.  Phys.  and  Path.  Researches,"  p.  170. 

8  [Dr.  Brown-Se'quard  has  observed  that  section  of  the  pneumogastric  nerves  is  fol- 
lowed by  paralysis  and  dilatation  of  the  blood-vessels  of  the  heart,  and  that  the  excitation 
of  these  nerves  (by  galvanism  or  otherwise)  produces  contraction  of  these  blood-vessels. 
He  explains  by  this  contraction  the  stoppage  of  the  heart's  action,  when  the  Medulla 
Oblongata  or  the  pneumogastric  nerves  are  galvanized,  as  in  Weber's  experiments.  The 
heart,  according  to  Dr.  S^quard's  theory,  owing  its  contractions  to  an  excitation  produced 
by  some  element  of  the  blood  existing  in  the  small  arteries  and  veins,  ceases  to  beat, 
when  the  blood  is  expelled  from  these  vessels  by  their  contraction.  If  it  is  objected  to 
this  view,  that  the  effect  of  galvanization  is  immediate,  and  that  the  arteries  and  veins, 
possessing  only  nbro-muscular  cells,  cannot  contract  suddenly,  it  may  be  answered,  that 
it  is  a  fact  that,  although  there  are  only  organic  or  non-striated  muscular  fibres  in  these 
vessels,  they  do  contract  immediately  when  the  pneumogastric  nerves  are  galvanized :  and  he 


244  OF    THE    CIRCULATION    OF    THE    BLOOD. 

240.  In  like  manner,  it  may  be  shown,  that  although  the  Heart's  action  con- 
tinues after  the  entire  separation  of  the  organ  from  the  chief  centres  of  the  Sym- 
pathetic system,  and  therefore  cannot  be  dependent  on  any  stimulus  derived  from 
them,  yet  that  it  may  be  affected  by  influences  transmitted  through  their  nerves. 
Thus  it  has  been  stated  by  a  large  number  of  experimenters,  that  galvanic  irritation 
of  the  cervical  trunks  of  the  Sympathetic,  accelerates  the  ordinary  rhythmical 
movements  of  the  heart,  and  re-excites  them  when  they  have  recently  ceased ; 
and  though  the  results  of  former  researches  on  this  point  are  not  free  from  fallacy,1 
yot  the  application  of  the  electro-magnetic  current  to  the  cervical  trunk  of  this 
nerve  so  constantly  produces  the  effect,  that  there  can  be  no  longer  any  reason- 
able doubt  upon  this  point.  There  is  reason  to  believe,  on  the  other  hand,  that 
the  depressing  effects  of  shock  (§  238)  may  be  exerted  no  less  directly  through 
the  Sympathetic  than  through  the  Cerebro-spinal  system ;  and  that  considerable 
disturbance  may  ensue  from  lesions  of  such  parts  of  it  (at  least)  as  are  most 
nearly  connected  with  the  heart.  For  the  well-known  fact  of  sudden  death 
not  unfrequently  resulting  from  a  blow  on  the  epigastric  region,  especially  after 
a  full  meal,  without  any  perceptible  lesion  of  the  viscera,  seems  to  indicate  that  a 
violent  impression  upon  the  widely-spread  caeliac  plexus  of  Sympathetic  nerves 
(which  will  be  much  more  extensively  communicated  to  them  when  the  stomach 
is  full,  than  when  it  is  empty),  may  cause  the  immediate  cessation  of  the  Heart's 
action,  in  the  same  manner  as  a  severe  injury  of  the  Brain  or  Spinal  Cord. 
And  a  case  has  been  put  on  record,  in  which  the  heart's  pulsations  were  occa- 
sionally checked  for  an  interval  of  from  4  to  6  beats,  its  cessation  of  action 
giving  rise  to  the  most  fearful  sensations  of  anxiety,  and  to  acute  pain  passing 
up  to  the  head  from  both  sides  of  the  chest, — these  symptoms  being  connected, 
as  appeared  on  a  post-mortem  examination,  with  the  pressure  of  an  enlarged 
bronchial  gland  upon  the  great  cardiac  nerve.2  The  very  difficulty  of  obtaining 
experimental  evidence  of  any  such  influence,  however,  notwithstanding  the  ex- 
has  discovered  that  the  same  thing  takes  place  in  the  blood-vessels  of  the  ear,  when  the 
sympathetic  nerve  is  galvanized,  in  the  cervical  region. 

If  the  view  of  Dr.  Sequard  be  correct,  we  ought  to  find  that  the  heart  will  beat,  if 
during  the  stoppage  produced  by  galvanization  of  the  medulla  oblongata,  we  substitute 
for  the  missing  excitation  (in  consequence  of  the  expulsion  of  the  blood  from  the  arteries 
and  veins),  another  stimulus.  This  has  been  done,  and  it  is  found  that  a  mechanical  or 
galvanic  excitation  re-establishes  the  movements  of  the  heart. 

Another  fact  has  been  discovered  by  Dr.  Se'quard,  which  he  considers  very  important. 
When  a  galvanic  current  is  applied  to  the  heart  or  to  the  pneumogastric  nerves  in  the 
neighborhood  of  this  organ,  it  is  known  that  its  pulsations  are  not  stopped  by  it,  and  that 
sometimes,  on  the  contrary,  they  appear  to  be  quicker  and  stronger.  Now,  if  the  theory 
of  Dr.  Se'quard  be  right,  how  to  explain  this  ?  It  may  be  readily  done ;  in  this  case,  the 
vessels  of  the  heart  are  contracted,  as  when  the  medulla  oblongata  is  galvanized, — but  the 
muscular  fibres  are  directly  excited  by  the  current,  which  produces  the  same  effects  as  the 
missing  excitant  expelled  from  the  vessels.  The  truth  of  this  explanation  is  proved  by 
the  fact  discovered  by  Dr.  Se'quard,  that  if  the  galvanic  current  is  interrupted  the  heart 
ceases  at  once  to  beat,  and  resumes  its  action  if  the  current  is  applied  again. 

Another  very  important  fact  is,  that  if  an  energetic  galvanic  excitation  is  applied  to  the 
Medulla  oblongata  of  a  frog,  for  ten,  fifteen  or  twenty  minutes  (sometimes  five  minutes 
are  sufficient),  the  heart,  which  had  stopped  at  once,  resumes  its  action.  This  fact,  dis- 
covered by  the  brothers  Weber,  and  unexplained  by  them,  is  thus  explained  by  Dr. 
Sequard.  He  says,  that  the  vessels  of  the  heart,  as  well  as  the  vessels  of  any  other  part 
of  the  body,  cannot  remain  contracted  a  very  long  while,  their  contractility  diminishing 
gradually  during  their  contraction.  He  has  seen  the  same  thing  when  he  applied  gal- 
vanism to  the  cervical  sympathetic  nerve,  the  vessels  of  the  ear  remained  contracted  five 
or  six  minutes,  or  a  little  more,  and  then  gradually  became  dilated,  although  the  excitation 
of  the  nerve  was  continued. — ED.] 

1  See  Dr.  John  Reid,  in  "Cyclop,  of  Anat.  and  Physiol.,"  vol.  ii.  p.  613. 

2  "Muller's  Archiv.,"  1841,  heft  iii. ;  and  "Brit,  and  For.  Med.  Rev.,"  Oct.  1841.— It 
may  be  surmised  that  in  many  cases  of  angina  pectoris,  in  which  no  lesion  adequate  to  ac- 
count for  death  could  be  discovered,  some  affection  of  the  cardiac  plexus  might  have  been 
traced  on  more  careful  examination. 


ACTION    OF    THE    HEAET.  245 

traordinary  irritability  of  the  Heart,  seems  to  show  that  the  ordinary  movements 
of  the  organ  are  but  little  dependent  upon  nervous  influence  of  any  kind. 

241  The  only  centres  of  nervous  power,  to  which,  consistently  with  the  fore- 
going facts,  the  constant  maintenance  of  the  Heart's  action  could  be  attributed, 
are  the  numerous  ganglia,  forming  part  of  the  Sympathetic  system,  which  are 
dispersed  through  its  substance,  but  which  are  brought  into  connection  with  each 
other,  and  with  the  cervical  and  dorsal  ganglia,  by  communicating  fibres. 
These,  it  has  been  surmised,  may  act  as  centres  of  *  reflex '  action,  and  may  thus 
keep-up  the  contractions  of  the  heart,  after  its  complete  withdrawal  from  the  in- 
fluence of  the  Cerebro-spinal  and  of  the  principal  Sympathetic  centres;  just  as 
the  ganglia  contained  in  the  separated  segments  of  the  body  of  a  Centipede,  are 
centres  of  movement  to  the  limbs  with  which  they  remain  in  connection.  But 
this  hypothesis  does  not  give  any  real  solution  to  the  difficulty;  for  in  every  case 
of  true  t  reflex '  action,  the  movement  is  excited  by  a  stimulus ;  and  no  rhythmi- 
cal succession  of  movements  can  be  thus  excited,  save  by  the  successive  recur- 
rence of  stimuli  at  regular  intervals,  as  in  the  act  of  Respiration.  It  is  the  con- 
tinuance of  activity  after  all  conceivable  sources  of  stimulation  have  been  with- 
drawn, which  constitutes  the  real  difficulty  of  the  case;  and  if  the  operation  of 
such  stimuli  be  admitted  as  the  sources  of  reflex  action,  they  may  with  equal 
propriety  be  regarded  as  directly  acting  upon  the  contractile  fibre,  —  which,  as 
already  shown,  is  much  more  amenable  to  such  direct  excitation,  than  it  is  to 
nervous  influence;  and  preserves  its  capacity  for  being  impressed  by  the  former, 
during  a  much  longer  period  than  it  remains  capable  of  responding  to  the  latter. 
Moreover,  the  fact  that  this  movement  is  seen  to  commence  in  the  embryonic 
heart,  when  as  yet  its  parietes  consist  of  ordinary  cells,  and  no  nervous  structure 
exists  either  in  its  own  substance  or  in  the  body  at  large,  stands  in  complete 
opposition  to  the  idea,  that  nervous  force  is  in  any  way  concerned  in  maintain- 
ing this  rhythmical  action. 

242.  A  more  satisfactory  mode  of  accounting  for  the  rhythmical  movements 
of  the  Heart,  appears  to  the  Author  to  lie  in  regarding  them  as  an  expression  of 
the  peculiar  vital  endowments  of  its  Muscular  tissue.  For  so  long  as  this  tissue 
retains  its  integrity,  and  the  other  necessary  conditions  are  supplied,  so  long  does 
an  alternation  of  contraction  and  relaxation  appear  to  be  the  characteristic  and 
constant  manifestation  of  its  vital  activity;  just  as  ciliary  movement  is  in  cells 
of  one  class,  and  secreting  action  in  those  of  another. — But  it  may  be  said  that, 
in  attributing  to  the  muscular  structure  of  the  heart  a  self-moving  power,  we 
really  only  throw-back  the  question  into  the  obscurity  from  which  the  Physio- 
logist has  sought  to  draw  it.1  Such  is  far  from  being  the  case,  however,  if  it  can 
be  proved  that  this  self-moving  power  is  nothing  else  than  an  exertion  of  ordi- 
nary Muscular  Contractility  under  peculiar  conditions,  and  that  analogous  phe- 
nomena present  themselves  in  other  cases.2  Now  it  is  shown  elsewhere  (PRINC. 
OF  GEN.  PHYS.),  that  the  contraction  of  any  Muscle  upon  the  application  of  a 
stimulus,  must  be  attributed  to  an  exercise  of  Vital  force  engendered  by  previous 
acts  of  Nutrition.  The  stimulus  is  not  the  source  of  the  force,  but  only  sup- 
plies some  condition  which  is  requisite  for  its  manifestation ;  just  as  the  applica- 
tion of  the  discharger  to  the  Leyden  jar  (which  has  been  charged  by  the  previous 
action  of  the  Electrical  machine)  liberates,  so  to  speak,  its  pent-up  electricity, 

1  In  so  far  as  it  attributes  the  Heart's  action  to  causes  originating  in  itself,  this  doctrine 
may  be  stigmatized  as  nothing  else  than  the  old  notion  of  the  inherent  '  pulsific  virtue ' 
of  the  organ,  so  happily  ridiculed  by  Moliere  and  Swift.  But  there  is  really  just  the  same 
difference  between  the  two,  as  between  the  doctrine  of  Vital  Forces,  which  it  has  been  the 
Author's  object  to  unfold  in  this  and  the  companion  Treatises,  and  the  old  notion  of  the 
'  vital  principle'  which  was  held  to  account  for  everything  not  otherwise  explicable. 

a  It  cannot  be  too  constantly  borne  in  mind,  in  this  and  other  instances,  that  to  explain 
a  phenomenon  in  Physiology  or  in  any  other  science  whatever,  is  nothing  else  than  to  show 
that  it  is  conformable  to  some  general  law,  and  that  it  is  thus  a  result  of  some  previously- 
recognised  cause,  which  is  common  to  it  with  a  number  of  other  previously-observed  phe- 
nomena. (See  Mr.  John  Mill's  "System  of  Logic,"  book  iii.  chap,  xii.) 


246  OF    THE    CIRCULATION    OF    THE    BLOOD. 

and  allows  this  to  display  itself  as  an  active  force.  Now,  just  as  the  Leyden  jar 
may  be  so  charged  with  electricity,  as  to  discharge  itself  spontaneously,  so  it  is 
easy  to  conceive  that  a  Muscle  may  be  so  charged  with  motility  (or  motor  force) 
as  to  execute  spontaneous  contractions;  and  of  the  existence  of  such  a  condition, 
we  have  valid  evidence.  For  there  are  many  local  phenomena  of  cramp  and 
spasm,  which  cannot  be  fairly  attributed  to  a  perverted  reflex  action  of  the  ner- 
vous system,  and  which  can  scarcely  be  referred  to  anything  else  than  an  over- 
charge of  muscular  power.  So,  again,  the  action  of  the  uterus,  as  shown  not 
merely  in  the  final  parturient  effort,  but  in  local  contractions  that  frequently 
occur  during  the  later  months  of  gestation  (simulating  the  movements  of  the 
fostus),  are  more  satisfactorily  accounted-for  by  considering  them  as  a  discharge 
of  accumulated  power,  than  in  any  other  mode.  And  the  respiratory  muscles, 
which  are  ordinarily  excited  to  rhythmical  movement  through  the  medium  of 
the  nervous  system,  may  execute  some  such  movements  of  themselves,  when  this 
source  of  stimulation  has  been  cut-off,  and  their  motility  has  accumulated  through 
inaction.1 

243.  It  is  not  very  difficult,  then,  to  apprehend,  that  the  ordinary  rhythmical 
movements  of  the  Heart  may  be  due  to  a  simple  excess  of  this  motility,  which  is 
continually  being  supplied  by  the  nutritive  operations,  and  is  as  constantly  dis- 
charging itself  in  contractile  action.  And  that  this  is  the  true  view  of  the  case, 
is  further  indicated  by  the  phenomena  attending  the  cessation  of  the  heart's 
action.  For  if  a  stimulus  be  applied  to  it  soon  after  it  has  ceased  to  execute 
spontaneous  movements,  this  stimulus  is  followed,  not  (as  in  ordinary  muscles) 
by  a  single  contraction  followed  by  a  relaxation,  but  by  a  succession  of  contrac- 
tions and  relaxations;2  thus  indicating  that  a  higher  degree  of  motility  than  that 
of  an  ordinary  muscle,  still  persists  in  its  tissue.  Gradually,  however,  the 
number  of  repetitions  becomes  smaller  and  smaller,  until  the  application  of  the 
stimulus  excites  but  a  single  contraction;  thus  indicating  that  the  motility  of  the 
heart  has  been  reduced,  by  the  cessation  of  the  nutritive  operations,  to  that  of 
an  ordinary  muscle.3 — This  view  of  the  case  is  not  in  the  least  inconsistent  with 
the  fact,  tha*  the  ordinary  ryhthmical  actions  of  the  heart  may  be  considerably 
modified,  both  as  to  their  rate  and  their  force,  by  stimuli  of  various  kinds 
brought  to  bear  upon  its  tissue,  either  through  the  Nervous  system,  or  by  direct 
contact.  Of  the  former  we  have  an  example  in  the  influence  of  the  emotions ; 
and  of  the  latter  in  the  violent  action  excited  by  an  unusual  rush  of  blood 
towards  the  heart,  in  consequence  of  sudden  muscular  action.4 
1  See  M.  Brown-SSquard,  in  "Gazette  Me'dicale,"  Dec.  22,  1849. 
a  This  phenomenon  has  no  parallel  among  the  manifestations  of  proper  reflex  action. 

3  If  we  pass  from  this  comparison  of  the  Heart  with  other  muscles,  to  the  general  phe- 
nomena of  rhythmical  movement  in  the  Animal  and  Vegetable  kingdoms,  the  proof  fur- 
nished by  analogy  that  the  immediate  source  of  its  action  lies  entirely  within  itself,  becomes 
much  stronger.     See  Princ.  of  Comp.  Phys.,  chap.  xii. 

4  [Ingenious  and  plausible  as  the  theory  of  the  author  is,  it  is  open  to  some  objectiona 
which  will  be  briefly  urged.     The  doctrine  set  forth  above,  implies  that  the  amount  of 
motility  in  the  heart  is  greater  than  in  the  other  involuntary  muscles.     If  we  can  judge 
of  the  amount  of  irritability  by  its  presence  after  death,  it  is  certainly  greater  in  the 
muscles  of  animal  life  than  in  the  heart :  and  if  the  author's  theory  were  true  we  ought 
to  see  in  them,  during  life,  the  apparently  spontaneous  contractions  which  take  place  after 
death,  for  their  irritability  is  greater  before  than  after  death.     Further,  if  the  action  of 
the  heart  depended  upon  an  excess  of  motility,  it  ought  to  beat  as  energetically  in  vacuo, 
as  in  either  hydrogen  or  nitrogen,  for  its  irritability  cannot  be  so  suddenly  destroyed  by 
the  mere  exhaustion  of  the  air  (§  236,  note).     The  heart  of  a  mammal  will  beat  for  five  or 
ten  minutes  in  these  gases,  and  the  heart  of  a  frog  has  been  known  to  continue  its  action 
for  a  day  under  the  same  conditions. 

Another  theory  has  recently  been  advanced,  which  seems  to  harmonize  more  with  known 
facts  than  any  other;  it  attributes  the  action,  of  the  heart  to  the  presence  of  carbonic  acid 
in  the  blood,  which,  under  some  circumstances,  is  capable  of  acting  as  an  excitant ;  and 
the  arguments  in  support  of  the  doctrine  are  as  follows: — ' 

1  See  "  Experimental  Researches  applied  to  Physiology  and  Pathology,"  by  E.  Brown- 
SSquard,  *>•  M  P.  &c.,  &c.  New  York,  1853. 


ACTION    OF    THE    HEART.  247 

244.  When  the  Heart  is  exposed  in  a  living  animal,  and  its  movements  are 
attentively  watched,  they  are  seen  to  follow  each  other  with  great  regularity.  In 

1 .  When  a  -warm-blooded  animal  is  prevented  from  breathing  by  pressure  applied  to  the 
trachea,  it  will  be  found  that  the  action  of  the  heart  is  notably  increased  for  one  or  two 
minutes,  and  this  not  on  account  of  the  emotion  of  fear  in  the  animal,  for  the  same  phe- 
nomena take  place  when  the  animal  has  previously  been  deprived  of  consciousness  by  the 
action  of  chloroform. 

The  same  phenomenon  has  been  observed  in  the  human  subject,  in  whom  the  suspension 
of  respiratory  movements  was  attended  during  the  last  part  of  the  process,  by  an  accele- 
ration of  the  heart's  movements;  and  this,  too,  during  the  maintenance  of  a  tranquil 
sitting  posture. 

The  effect  of  hanging  upon  the  pulse  is  familiar  to  all  who  have  observed  it ;  a  decided 
increase  being  observed,  and  this  after  consciousness  and  the  influence  of  emotion  have 
entirely  disappeared. 

2.  Dr.  John  Reid  observed  that  when  the  hema-dynamometer  was  introduced  into  the 
femoral  artery  of  a  dog,  that  the  mercury  rose  in  the  instrument  within  a  minute  after  the 
stoppage  of  the  respiration  ;  th    same  result  was  obtained  in  twenty  cases.    He  attributes  this 
result  to  the  difficulty  which  black  blood  experiences  in  passing  the  systemic  capillaries. 
This  may  be  so  in  fact,  but  the  great  reason  is  the  increase  in  the/orce  of  the  heart,  and 
this  may  be  proved  by  a  simple  experiment.     If  the  hema-dynamometer  be  adapted  to 
the  abdominal  aorta,  and  the  chest  be  rapidly  opened,  and  a  ligature  applied  to  the  bra- 
chial  and  carotid  arteries,  it  will  be  found,  that  in  about  three  quarters  of  a  minute  after 
opening  the  chest,  and  half  a  minute  after  ligating  the  arteries  of  the  head  and  arm,  that 
the  mercury  rises  notably  in  the  instrument,  sometimes  as  much  as  two  inches.     It  results 
from  this  experiment,  that  the  heart  beats  more  strongly  immediately  after  the  commence- 
ment of  asphyxia. 

3.  Woodall,  quoted  by  Dr.  M.  Paine,  states  that  the  best  remedy  for  syncope  is  obstruc- 
tion of  the  respiration  by  momentarily  closing  the  nose  and  mouth.     If  this  be  true,  it 
accords  with  the  view  stated  above,  that  during  asphyxia  the  normal  cause  of  the  beatings 
of  the  heart  accumulate  in  the  blood. 

4.  If  a  frog  be  put  under  a  receiver  containing  oxygen  at  40°  or  50°  F.,  after  its  central 
nervous  system  is  destroyed,  its  heart  will  continue  to  beat  for  a  long  time ;  but  if  it  be 
put  into  carbonic  acid  at  the  same  temperature,  it  will  beat  very  quickly  at  first,  but  soon 
cease. 

5.  If  serum  of  the  blood  be  injected  into  the  arteries  of  the  heart,  so  as  to  expel  com- 
pletely all  the  blood  from  the  capillaries  of  the  organ,  its  action  will  be  almost  entirely 
suspended,  not  because  the  muscular  irritability  is  destroyed,  for  movement  may  still  be 
excited,  but  because  its  normal  excitant  has  been  removed. 

6.  When  the  heart  of  a  young  animal  is  put  into  hydrogen  gas,  its  movements  are 
scarcely  appreciably  affected  at  first,  but  they  cease  in  a  very  short  time.     WThen  it  is  put 
into  carbonic  acid  gas,  its  movements  are  at  first  increased  in  frequency  and  strength,  but 
they  soon  cease;  and  when  it  is  put  into  oxygen,  its  movements  are  slowly  increased  in 
frequency  and  strength,  and  they  last  for  a  long  time.     If  hydrogen  gas  be  artificially  in- 
troduced into  the  lungs  of  an  animal,  the  movements  after  a  short  time,  during  which  they 
are  unaffected,  go  on  steadily  diminishing  until  they  cease. 

When  carbonic  acid  is  injected,  the  movements  are  at  first  rapidly  increased,  but  they 
cease  after  a  short  time  also.  When  oxygen  is  introduced,  the  action  of  the  heart  becomes 
slowly  reduced  in  frequency,  but  it  continues  longer  than  under  other  circumstances. 

These  observations,  carefully  conducted,  seem  to  prove  that  venous  blood,  by  the  car- 
bonic acid  which  it  contains,  is  an  excitant  of  the  heart's  action.  If  other  phenomena 
connected  with  asphyxia,  and  occurring  after  death  from  other  causes,  such  as  the  dis- 
charge of  the  contents  of  the  intestinal  canal,  bladder  and  uterus,  the  spasmodic  action  of 
muscles,  the  contraction  of  the  iris,  and  the  cramps  and  twitchings  of  the  muscles  in 
Cholera,  be  taken  into  consideration,  it  seems  impossible  to  deny  the  agency  of  this 
element  in  their  production. 

The  rhythmical  contraction  of  the  heart  is  also  explicable  by  the  same  theory.  Accord- 
ing to  the  law  discovered  by  Schwann,  an  exciting  cause  which  is  capable  of  producing 
contraction  when  the  muscular  fibres  are  at  full  length,  cannot  maintain  the  contraction 
when  the  fibres  have  been  shortened,  the  fibre  consequently  relaxes  and  dilatation  ensues. 

The  same  fact  may  be  presented  in  other  words,  viz.,  that  the  resistance  to  contraction 
originating  in  the  displacement  of  the  constituent  particles  of  the  contractile  tissues,  in- 
creases inversely  as  the  shortening  of  the  fibres,  so  that  after  the  fibres  have  contracted 
under  the  influence  of  the  exciting  cause,  although  the  cause  may  continue  to  act,  dila- 
tation is  produced  by  the  force  resulting  from  the  resistance,  or  in  other  words  by  elas 
ticity.  If  the  exciting  cause  of  the  contraction  were  a  considerable  one,  there  would 
result  a  permanent  contraction :  and  it  is  so  when  galvanism  is  applied,  elasticity  then  not 


248       OF  THE  CIRCULATION  OF  THE  BLOOD. 

an  active  and  vigorous  state  of  the  circulation,  however,  they  are  so  linked  toge- 
ther, that  is  not  easy  to  distinguish  them  into  periods;  both  Auricles  contract- 
ing, and  also  dilating,  simultaneously;  and  both  Ventricles  doing  the  same. 
The  systole  or  contraction  of  the  Ventricles  corresponds  with  the  projection  of 
blood  into  the  arteries ;  whilst  the  diastole  or  dilatation  of  the  Ventricles  coin- 
cides with  the  collapse  of  the  arteries.  The  contraction  of  the  Ventricles,  and 
that  of  the  Auricles,  alternate  with  one  another;  each  taking  place  (for  the 
most  part,  at  least),  during  the  dilatation  of  the  other.  But  there  is  a  period 
during  which  the  Auricles  and  Ventricles  of  both  sides  are  dilating  together. 
This  occurs  during  the  first  part  of  the  Ventricular  diastole;  for  at  the  conclu- 
sion of  the  systole,  the  Auricles  are  far  from  being  completely  filled,  and  they 
go-on  receiving  an  additional  supply  from  the  great  Veins  (a  portion  of  which, 
however,  passes  at  once  into  the  Ventricles)  until  after  the  middle  of  the  Ven- 
tricular diastole,  by  which  time  they  become  fully  distended  and  immediately 
contract.  The  contraction  of  the  Auricles  is  synchronous,  therefore,  with  only 
the  second  stage  of  the  Ventricular  diastole ;  and  their  dilatation  is  going-on 
during  the  whole  period  of  the  Ventricular  systole.  Thus  whilst  the  entire 
period  that  intervenes  between  one  pulsation  and  another,  is  nearly  equally 
divided  between  the  systole  and  diastole  of  the  Ventricles,  the  division  is  very 
unequal  as  regards  the  Auricles;  scarcely  more  than  one-eighth  of  the  whole 
being  occupied  in  their  contraction,  and  the  remainder  being  taken-up  by  their 
dilatation.  The  following  tabular  view  will  perhaps  make  the  relations  of  the 
several  parts  of  this  series  more  intelligible  : — 

AURICLES.  VENTRICLES. 

7  f  Dilatation.  Contraction.  £ 

¥  \  Continued  Dilatation.  First  stage  of  Dilatation.      ~»  -. 

J     Contraction.      .  Second  Stage  of  Dilatation,  j  * 

245.  In  the  systole  of  the  Ventricles,  their  surface  becomes  rugous ;  the  su- 
perficial veins  swell;  the  carnese  columnse  of  the  left  ventricle  are  delineated; 

being  sufficiently  powerful  to  produce  dilatation.  But  with  a  weak  exciting  cause,  such 
as  carbonic  acid,  the  result  is  different.  When  that  cause  is  more  powerful,  as  in  asphyxia, 
the  shortening  of  the  fibres  takes  place  more  rapidly,  and  is  more  decided ;  but  even  then 
it  is  not  sufficient  to  maintain  contraction,  the  tendency  to  dilatation  being  at  the  same 
time  increased. 

It  should  be  stated  in  this  connection,  that  the  excitant  cause  is  not  at  all  times  equally 
powerful.  The  small  blood-vessels  and  the  capillaries  being  compressed  during  muscular 
contraction,  there  is  at  that  time  a  diminution  of  excitation;  this  is  in  itself  sufficient  to 
explain  the  alternate  contraction  and  dilatation,  although  the  amount  of  diminution  of 
calibre  must  be  very  little,  if  it  exist  at  all,  in  some  organs,  as  for  instance  in  the  heart, 
ffhen  composed  of  cells  only. 

It  may  be  asked  how  it  is  that  the  heart  is  the  only  muscle  containing  striated  muscular 
fibres  which  presents  rhythmical  movements  ?  To  this  it  may  be  replied,  that  the  intensity 
of  the  stimuli,  the  degree  of  irritability,  and  the  resistance  which  a  muscle  has  to  over- 
come when  it  contracts,  are  three  elements  which  should  not  be  lost  sight  of  when  the 
comparative  action  of  muscles  is  examined.  Suppose  the  heart  possesses  the  same 
amount  of  irritability  as  another  muscle ;  if  the  stimulus  is  the  same,  and  the  resistance 
the  same  in  both,  the  result  will  be  the  same.  But  if  the  stimulus  be  greater  in  the  heart, 
and  the  resistance  less,  then  with  the  same  amount  of  irritability,  or  even  less,  in  the  heart 
than  in  the  other  muscles,  the  heart  will  respond  and  not  the  other  muscles.  Now,  a 
pimple  examination  of  the  vessels  of  the  heart,  proves  that  they  contain  more  blood,  and 
consequently  a  greater  amount  of  stimulus  than  the  other  striated  muscles.  Moreover,  as 
the  heart  is  not  inserted  into  heavy  bones  to  be  moved,  it  has  less  resistance  to  overcome 
than  the  muscles  of  animal  life.  There  are  some  muscles,  such  as  those  of  the  face  and 
the  diaphragm,  which,  being  almost  without  external  resistance,  are  more  easily  moved 
both  before  and  after  death,  than  the  muscles  of  the  limbs.  On  this  account,  therefore, 
although  there  is,  in  all  the  muscles  of  the  body,  a  principle,  which  is  an  exciting  cause 
of  contraction,  no  contractions  take  place,  either  because  the  quantity  is  not  sufficient,  or 
because  the  resistance  is  greater  in  many  muscles  than  it  is  in  the  heart. — ED.  '] 

1  For  a  fuller  exposition  of  this  theory,  see  Dr.  Brown-Sequard  in  the  "Medical 
Examiner,"  1853. 


ACTION    0V    THE    HEART.  249 

arid  the  curved  fibres  of  the  conical  termination  of  the  loft  ventricle,  which  alone 
constitutes  the  apex  of  the  heart,  become  more  manifest.1      During  their  contrac- 
tion, the  form  of  the  Ventricles  undergoes  a  very  marked  change,  the  apex  of 
the  heart  being  drawn-up  towards  its  base,  arid  its  whole  shape  becoming  much 
more  globular.     The  movement  of  the  apex,  however,  is  by  no  means  a  simple 
elevation;  for,  owing  to  the  peculiar  arrangement  of  the  fibres  of  this  part  of 
the  heart,  it  is  made  to  describe  a  spiral  curve  from  right  to  left,  and  from  behind 
forwards.     It  is  to  this  change  in  the  form,  of  the  heart,  and  in  the  position  of 
its  apex,  rather  than  to  change  in  the  place  of  the  organ  as  a  whole,  that  we  are 
to  attribute  its  impulse  against  the  parietes  of  the  chest ;  for  if  any  advance  and 
recedence  do  take  place,  from  the  various  causes  which  have  been  assigned  by 
different  observers  (such  as  the  pressure  of  the  blood  in  the  direction  opposite  to 
that  of  the  orifices  through  which  it  is  being  impelled,  the  tendency  of  the  aorta 
to  straighten  itself  when  distended  with  blood,  and  the  elastic  recoil  of  the  parts 
about  the  base  of  the  heart),  this  must  be  extremely  trifling  in  its  amount,  since 
all  these  causes  require  distension  of  the  organ  with  blood  for  their  operation, 
and  the  tilting-forward  of  the  lower  part  of  the  heart  still  ensues  when  its  apex 
has  been  cut-off,  and  when  no  such  tension  can  be  exercised. — The  diastole  of 
the  ventricles,  according  to  Cruveilheir  (loc.  cit.),  has  the  rapidity  and  energy 
of  an  active  movement;  triumphing  over  pressure  exercised  upon  the  organ,  so 
that  the  hand  closed  upon  it  is  opened  with  violence.     This  is  an  observation  of 
great  importance ;  and  it  concurs  with  observations  made  upon  the  heart  when 
emptied  of  blood,  to  show  that  the  diastole  is  not  a  mere  relaxation  of  the  mus- 
cular fibres,  permitting  the  cavity  to  be  distended,  but  is  effected  by  some  power 
inherent  in  the  walls  themselves.2     Even  the  dilatation  of  the  Auricles  appears 
to  be  much  greater  than  can  be  accounted-for  by  any  vis  a  tergo  of  the  blood 
(which,  as  will  be  shown  hereafter,  is  extremely  small  in  the  venous  system),  or 
by  the  elasticity  of  its  substance;  for  it  was  observed  in   this  case  to  be  so 
marked,  that  the  right  auricle  seemed  ready  to  burst,  so  great  was  its  distension, 
and  so  thin  were  its  walls.     Moreover,  the  large  veins  near  the  heart  contract 
simultaneously  with  the  auricle,  and  not  whilst  it  is  dilating;  so  that  they  can 
have  no  influence  in  causing  its  distension. 

246.  The  course  of  the  circulating  fluid  through  the  Heart,  and  the  action  of 
its  different  valves,  will  now  be  briefly  described. — The  Venous  blood  which  is 
returned  by  the  ascending  and  descending  Vena  Cava,  enters  the  right  Auricle 
during  its  diastole  (Fig.  64);  part  of  it  flows-on,  as  already  mentioned,  into  the 
right  Ventricle  during  the  earlier  portion  of  its  diastole ;  but  the  Auricle,  being 
filled  before  the  Ventricle,  then  contracts  and  discharges  its  contents  through  the 
tricuspid  valves  into  the  Ventricle,  which  it  thus  completely  distends.  The 
reflux  of  blood  into  the  veins  during  the  auricular  systole,  is  impeded  by  the 
contraction  of  their  own  walls,  and  by  the  valves  with  which  they  are  furnished; 
but  these  valves  are  so  formed,  as  not  to  close  accurately,  especially  when  the 
tubes  are  distended ;  so  that  a  small  amount  of  reflux  usually  takes  place,  and 
this  is  much  increased  when  there  is  any  obstruction  to  the  pulmonary  circulation. 
Whilst  the  right  Ventricle  is  contracting  upon  the  blood  that  has  entered  it,  the 
carnese  columnse,  which  contract  simultaneously  with  its  proper  walls,  put  the 
chordae  tendinese  upon  the  stretch ;  and  these  draw  the  flaps  of  the  Tricuspid 
valve  into  the  auriculo-ventricular  axis.  The  blood  then  getting  behind  them, 
and  being  compressed  by  the  contraction  of  the  ventricle,  forces  the  flaps  together, 
in  such  a  manner  as  to  close  the  orifice;  but  they  do  not  fall  suddenly  against 

1  See  the  account  given  by  M.  Cruveilheir  of  a  remarkable  case  of  Ectopia  Cordis,  in 
"Gazette  Mddicale,"  Aout  7,  1841. 

2  The  only  power  whose  existence  has  been  hitherto  admitted,  as  competent  to  produce 
such    an  effect,  is  the  elasticity  of  the  tissues  composing  the  walls  of  the  heart.     The 
Author  would  suggest,  however,  whether  there  may  not  exist  in  Muscle  an  active  force  of 
elongation,  as*  well  as  an  active  force  of  contraction;  arising  from  the  mutual  repulsion  of 
particles,  whose  mutual  attraction  is  the  occasion  of  the  shortening. 


250  OF    THE    CIRCULATION    OF    THE    BLOOD. 

[Fro.  64. 


'l^ie  Anatomy  of  the  Heart:  1,  the  right  auricle;  2,  the  entrance  of  the  superior  vena  cava; 
3,  the  entrance  of  the  inferior  cava;  4,  the  opening  of  the  coronary  vein,  half  closed  by  the  coro- 
nary valve;  5,  the  Eustachian  valve;  6,  the  fossa  ovalis,  surrounded  by  the  annulus  ovalis;  7, 
the  tubereulum  Loweri;  8,  the  musculi  pectinati  in  the  appendix  auriculae;  9,  the  auriculo-ven- 
tricular  opening;  10,  the  cavity  of  the  right  ventricle;  11,  the  tricuspid  valve,  attached  by  the 
chordae  tendineae  to  the  carnese  columnae  (12) ;  13,  the  pulmonary  artery,  guarded  at  its  com- 
mencement by  three  semilunar  valves;  14,  the  right  pulmonary  artery,  passing  beneath  the  arch 
and  behind  the  ascending  aorta :  15,  the  left  pulmonary  artery,  crossing  in  front  of  the  descend- 
ing aorta;  *,  the  remains  of  the  ductus  arteriosus,  acting  as  a  ligament  between  the  pulmonary 
artery  and  arch  of  the  aorta;  the  arrows  mark  the  course  of  the  venous  blood  through  the  right 
side  of  the  heart;  entering  the  auricle  by  the  superior  and  inferior  cava,  it  passes  through  the 
auriculo- ventricular  opening  into  the  ventricle,  and  thence  through  the  pulmonary  arterv  to  the 
lungs;  16,  the  left  auricle;  17,  the  openings  of  the  four  pulmonary  veins ;  18,  the  auriculo-ven- 
tricular  opening;  19,  the  left  ventricle;  20,  the  mitral  valve,  attached  by  its  chordae  tendineae  to 
two  large  columnae  carneze,  which  project  from  the  walls  of  the  ventricle;  21,  the  commencement 
and  course  of  the  ascending  aorta  behind  the  pulmonary  artery,  marked  by  an  arrow  ;  the  en- 
trance of  the  vessel  is  guarded  by  three  semilunar  valves ;  22,  the  arch  of  the  aorta.  The  com- 
parative thickness  of  the  two  ventricles  is  shown  in  the  diagram.  The  course  of  the  arterial 
blood  through  the  left  side  of  the  heart  is  marked  by  arrows.  The  blood  is  brought  from  the 
lungs  by  the  four  pulmonary  veins  into  the  left  auricle,  and  passes  through  the  auriculo-ventri- 
cular  opening  into  the  left  ventricle,  whence  it  is  conveyed  by  the  aorta  to  every  part  of  the  body.] 

each  other,  as  is  the  case  with  the  semilunar  valves,  since  they  are  restrained  by 
the  chordae  tendinese;  whence  it  is  that  no  sound  is  produced  by  their  closure. 
The  blood  is  expelled  by  the  ventricular  systole  into  the  Pulmonary  Artery,  which 
it  distends,  passing  freely  through  its  Semilunar  valves ;  but  as  soon  as  the  vis  a 
tergo  ceases,  and  reflux  might  take  place  by  the  contraction  of  the  arterial  walls, 
the  valves  are  filled-out  by  the  backward  tendency  of  the  blood,  and  completely 
check  the  return  of  any  portion  of  it  into  the  ventricle.  The  blood,  after  having 
circulated  through  the  lungs,  returns  as  Arterial  blood,  by  the  Pulmonary  Veins, 
to  the  left  Auricle ;  whence  it  passes  through  the  Mitral  valve  into  the  left  Ven- 
tricle, and  thence  into  the  Aorta  through  its  Semilunar  valves, — in  the  same 
manner  with  that  on  the  other  side,  as  just  described. 

247.  There  are,  however,  some  important  differences  in  the  structure  and 
functional  actions  of  the  two  divisions  of  the  Heart,  which  should  be  here 
adverted-to. — The  walls  of -the  left  Ventricle  are  considerably  thicker  than  those 
of  the  right ;  and  its  force  of  contraction  is  much  greater.  The  following  are 
the  comparative  results  of  M.  Bizot's  measurements,1  taking  the  average  of  Males 
from  16  to  79  years: — 

1  "  Mem.  de  la  Soc.  Medic.  d'Observation  de  Paris,"  torn.  i. 


ACTION    OF    THE    HEART.  251 

Base.  Middle.  Apex. 

Left  Ventricle 4£    lines  5^  lines  3|    lines. 

Right  Ventricle lj|  lines  If  lines  1^  lines. 

In  the  Female,  the  average  thickness  is  somewhat  less.  It  will  be  seen,  that  the 
point  of  greatest  thickness  in  the  left  Ventricle  is  near  its  middle ;  while  in  the 
right,  it  is  nearer  the  base.  The  thickness  of  the  former  goes-on  increasing 
during  all  periods  of  life,  from  youth  to  advanced  age ;  whilst  that  of  the  ri^ht  is 
nearly  stationary.  The  left  Auricle  is  somewhat  thicker  than  the  right ;  the 
average  thickness  of  the  former  being,  according  to  Bouillaud,  a  line  and  a  half; 
whilst  that  of  the  latter  is  only  a  line.  In  regard  to  the  relative  capacities  of 
the  right  and  left  cavities,  much  difference  of  opinion  has  prevailed.  The  rujht 
Auricle  is  generally  allowed  to  be  somewhat  more  capacious  than  the  left;  and 
the  same  is  commonly  taught  of  the  right  Ventricle.  So  much  fallacy  may  arise, 
however,  from  the  peculiar  condition  of  the  animal  at  the  moment  of  death,  that 
this  is  not  easily  proved,  and  is  indeed  by  no  means  certain. — The  average 
capacity  of  the  cavities  may  be  estimated,  in  the  full-sized  Heart,  at  about  three 
ounces;  that  of  the  Auricles  being  probably  a  little  less;  and  that  of  the  Ven- 
tricles a  little  greater.  It  has  been  shown  that  the  Ventricles  receive  more  blood 
from  the  Auricles,  than  the  latter  could  transmit  to  them  by  simply  emptying 
themselves  once. — There  is  a  well-known  anatomical  difference  between  the 
auriculo-ventricular  valves  on  the  two  sides,  which  has  given  rise  to  the  diversity 
of  name;  and  this  seems,  from  the  researches  of  Mr.  King,1  to  be  connected 
with  an  important  functional  difference.  The  Mitral  valve  closes  much  more 
perfectly  than  the  Tricuspid;  and  the  latter  is  so  constructed  as  to  allow  of  con- 
siderable reflux,  when  the  cavities  are  greatly  distended.  Many  occasional  causes 
tend  to  produce  an  accumulation  of  blood  in  the  venous  system,  and  in  the  right 
side  of  the  Heart;  thus,  any  obstruction  to  the' pulmonary  circulation,  cold, 
compression  of  the  venous  system  by  muscular  action,  &c.,  are  known  to  favour 
such  a  condition.  This  is  a  state  of  peculiar  danger,  from  a  liability  which  over- 
distension  of  the  Ventricular  cavity  has,  to  produce  a  state  of  muscular  paralysis ; 
and  in  the  structure  of  the  Heart  itself,  there  seems  to  be  a  provision  against  it. 
For,  when  the  ventricle  is  thus  distended,  the  Tricuspid  valves  do  not  close  prop- 
erly; and  a  reflux  of  blood  is  permitted,  not  only  into  the  Auricle,  but  also 
(through  the  imperfect  closure  of  their  valves  under  the  same  circumstances) 
into  the  large  veins.  This  is  proved  by  the  fact  several  times  observed  by  Dr. 
J.  Reid  in  his  experiments  upon  Asphyxia,  &c.,  that  when  the  action  of  the  right 
ventricle  had  ceased  from  over-distension,  he  could  frequently  re-excite  it,  not 
merely  by  puncturing  its  walls,  but  by  making  an  opening  in  the  jugular  vein.2 
This  fact  evidently  affords  an  indication  of  great  importance  in  the  treatment  of 
Asphyxia;  and  it  explains  the  reflux  of  blood,  or  venous  pulse,  which  is  frequently 
observed  in  cases  of  pulmonary  disease,  and  which,  according  to  Mr.  King, 
always  exists  even  in  health,  though  in  a  less  striking  degree. 

248.  When  the  ear  is  applied  over  the  cardiac  region,  during  the  natural 
movements  of  the  Heart,  two  successive  sounds  are  heard,  each  pair  of  which 
corresponds  with  one  pulsation ;  there  is  also  an  interval  of  silence  between  each 
recurrence,  and  the  sound  that  immediately  follows  this  interval  is  known  as  the 
Jirst  sound,  the  other  as  the  second.  —  The  first  sound  is  dull  and  prolonged ;  it 
is  evidently  synchronous  with  the  impulse  of  the  Heart  against  the  parietes  of 
the  chest,  and  also  with  the  pulse,  as  felt  near  the  heart ;  it  must,  therefore,  btf 
produced  during  the  Ventricular  Systole. — The  second  sound,  which  is  short  and 
sharp,3  follows  so  immediately  upon  the  conclusion  of  the  first,  that  it  cannot 
take  place  during  the  auricular  systole  as  some  have  supposed,  but  must  be  as- 

1  "Guy's  Hospital  Reports,"  vol.  ii. 

a  "  Physiol.,  Anatom.,  and  Pathol.  Researches,"  chap.  iii. 

3  The  difference  between  these  two  sounds  is  well  expressed  (as  Dr.  C.  J.  B.  Williams 
has  remarked)  by  articulating  the  syllables  lubb,  dup. 


252       OF  THE  CIRCULATION  OF  THE  BLOOD. 

signed  to  the  first  stage  of  the  ventricular  diastole,  when  the  auricles  also  are 
dilating. — With  regard  to  the  relative  duration  of  the  two  sounds,  and  of  the 
interval,  widely  different  estimates  have  been  formed.  Thus  Laennec  considered 
the  lengths  of  the  periods  of  sound  and  silence  to  be  respectively  8-4 ths  and 
l-4th  of  the  whole  interval  between  one  pulse  and  another;  by  Dr.  Williams, 
and  by  Barth  and  Roger,  the  relative  lengths  of  these  periods  have  been  esti- 
mated at  2-3rds  and  l-3rd  ;  whilst  the  recent  experiments  of  Volkmann  l  (made 
by  adjusting  two  pendulums  to  vibrate  precisely  in  the  two  periods)  indicate  that 
they  are  almost  precisely  equal. 

249.  The  causes  of  these  Sounds,  and  more  especially  of  the  first,  have  been 
the  subjects  of  much  discussion.  A  number  of  very  distinct  actions  are  taking- 
place  during  the  period  of  the  production  of  the  latter;  and  each  of  these  has 
been  separately  fixed-ou  as  competent  to  produce  it.  Thus  we  have  (a)  the  im- 
pulse of  the  heart  against  the  parietes  of  the  chest;  (6)  the  contraction  of  the 
muscular  walls  of  the  ventricles ;  (c)  the  tension  of  the  valves  of  the  auriculo- 
ventricular  orifices,  and  the  backward  impulse  of  the  blood  against  them ;  (d) 
the  rush  of  blood  through  the  narrowed  orifices  of  the  aorta  and  pulmonary 
artery;  and  (e)  the  general  molecular  collision  of  the  particles  of  the  blood 
amongst  each  other,  and  their  friction  against  the  walls  of  the  ventricles.  Each 
of  these  causes  has  probably  some  share  in  the  production  of  the  result. 

a.  That  the  first  sound  is  partly  due  to  the  impulse,  seems  proved  by  the  fact, 
that  when  the  impulse  is  prevented,  by  the  removal  of  the  portion  of  the  wall 
of  the  chest  against  which  it  takes  place,  the  sound  is  much  diminished  in  in- 
tensity; and  also  by  the  circumstance,  that  when  the  ventricles  contract  with 
vigour,  the  greatest  intensity  of  the  sound  is  over  the  point  against  which  the 
impulse  takes  place.     Moreover,  the  prolonged  nature  of  the  sound  is  by  no 
means  inconsistent  with  this  view ;  since  the  impulse  is  not  a  mere  stroke,  so 
much  as  a  continued  pressure.     But  that  the  sound  is  not  entirely  due  to  this 
cause,  is  also  evident  from  the  fact,  that  it  may  still  be  heard  when  the  heart  is 
contracting  out  of  the  body,  or  when  the  impulse  cannot  take  place. 

b.  That  the  sound  is  partly  muscular,  that  is,  produced  in  the  act  of  muscular 
contraction  (probably  by  the  friction  of  the  particles  of  the  muscle  against  each 
other,  see  PRINC.  OF  GEN.  PHYS.  Am.  Ed.),  would  appear  from  the  fact,  that  it  may 
be  still  perceived  after  the  heart  has  been  removed  from  the  body  and  completely 
drained  of  its  blood.2     But  that  this  is  not  its  only  source,  is  shown  by  the  great 
diminution  in  its  intensity,  which  is  observable  under  such  circumstances. 

c.  That  the  sudden  tension  of  the  auriculo-ventricular  valves,  with  the  reflux 
of  the  blood  against  them,  at  the  commencement  of  the  ventricular  systole,  is  a 
cause  of  sound,  would  seem  to  be  indicated  by  the  analogy  of  the  semilunar 
valves ;  and  an  experiment  by  Valentin,3  in  which  a  sound  in  some  degree  re- 
sembling the  first  sound  of  the  heart  was  produced  by  the  impulse  of  fluid  against 
a  tense  membrane,  has  been  adduced  in  confirmation  of  this  view.     But  it  is  to 
be  borne  in  mind,  that  these  valves  cannot  close-together  with  the  same  sudden- 
ness as  do  the  semilunar,  being  restrained  by  the  spring-like  tension   of  the 
carnese  columnae;  and,  moreover,  even  admitting  a  sound  to  be  produced  by 
their  closure,  such  a  sound  would  be  momentary,  and  would  not  possess  the  pro- 
longed character  of  the  true  first-sound.     Still  it  is  not  improbable  that  the 
tension  of  these  valves  serves  to  augment  by  resonance  the  sounds  produced  in 
other  ways. 

d.  That  the  rush  of  blood  through  the  narrowed  orifices  of  the  great  arterial 
trunks  is  really  a  cause  of  sound,  is  indicated  by  the  results  of  experiments  made 
upon  tubes  out  of  the  body,  and  upon  large  blood-vessels  through  which  the 

1  "  Die  Hamodynamik,  nach  Versuchen,"  p.  364. 

a  See  the  '  Report  of  the  London  Committee  upon  the  Sounds  of  the  Heart,'  in  the 
"Trans,  of  Brit.  Assoc  ,"  for  1836. 
*  "  Lehrbuch  der  Physiologic."  band  i.  p.  427. 


ACTION    OF    THE    HEART.  253 

blood  is  circulating ;  for  any  diminution  of  the  calibre  of  a  tube  through  which 
fluid  is  rapidly  moving,  gives-rise  to  a  continuous  murmur.  And  that  this  cause 
is  in  operation  in  the  heart,  is  specially  indicated  by  the  observations  of  Cru- 
veilhier  upon  the  case  already  cited ;  for  he  noticed  that  (the  effect  of  the  im- 
pulse being  there  in  abeyance)  the  greatest  intensity  of  the  first  sound  was,  like 
that  of  the  second,  at  the  base  of  the  heart,  in  the  region  from  which  the  great 
vessels  originate ;  whilst  he  could  discover  no  production  of  sound  in  the  region 
of  the  auriculo-ventricular  valves. 

e.  Lastly,  that  the  collision  of  the  particles  of  the  blood  with  each  other,  and 
with  the  tense  muscular  parietes  of  the  heart,  together  with  its  movement  over 
the  inequalities  of  the  internal  surface  of  the  ventricle,  will  become  a  cause  of 
sound,  may  be  suspected  from  what  happens  elsewhere,  and  more  especially 
from  the  production  of  a  very  distinct  sound  by  the  movement  of  blood  in  the 
interior  of  an  aneurism  ; '  but  that  this  cause,  if  it  have  a  real  existence,  is  much 
inferior  in  potency  to  the  preceding,  appears  from  the  fact  that  it  cannot  be  dis- 
tinguished from  it ;  and  that,  neither  separately  nor  combined,  do  they  give  a 
sufficient  account  of  the  phenomenon,  is  obvious  from  the  persistence  of  a  sound 
after  the  heart  has  been  completely  emptied  of  its  blood. 

250.  It  is  only  by  thus  regarding  the  first  sound  as  made  up  by  several  factors, 
that  we  can  adequately  account  for  the  operation  of  Pathological  causes  in  modi- 
fying it;  since  the  greater  part  of  the  bruits  and  murmurs  that  are  produced  by 
morbid  changes  in  the  Heart  and  in  its  valves,  are  really  modifications  of  the 
natural  sound,  not  additions  to  it. 

251.  That  the  second  sound  is  produced  in  the  act  of  closure  of  the  Semilunar 
valves,  is  now  almost  universally  admitted ;  the  simple  hooking-back  one  of  these 
valves  by  a  curved  needle  against  the  side  of  the  artery,  so  as  to  permit  a  reflux 
of  blood  into  the  ventricle,  being  sufficient  to  suppress  this  sound  altogether. 
Whether  it  proceeds  from  the  tension  of  the  valves  themselves,  or  from  the  re- 
coil of  the  blood  against  them,  or  from  both  causes  combined,  has  not  been 
clearly  determined ;  probably  the  last  is  the  true  account  of  it. — When  the  first 
sound  is  altered  by  disease  of  the  semilunar  valves,  occasioning  obstruction  to 
the  exit  of  blood,  the  second  sound  also  is  aifected  in  its  character;  and  if  the 
disease  be  of  such  a  kind  as  to  prevent  these  valves  from  effectually  closing,  a 
reflux  of  blood  takes  place  into  the  ventricle  at  tl\e  time  of  its  diastole,  causing 
a  rushing  sound  that  is  analogous  to  the  ordinary  first  sound,  or  to  some  of  its 
modifications.     Thus  the  second  sound  may  come  to  acquire  so  completely  the 
character  of  the  first,  that  it  is  difficult  to  distinguish  the  two  in  any  other  way, 
than  by  the  synchronousness  of  the  first  with  the  heart's  stroke  and  with  the 
pulse  in  the  arteries.2 

252.  There  seems  adequate  reason  to  believe  that  the  whole,  or  very  nearly 
the  whole,  of  the  blood  contained  in  the  Ventricles,  is  discharged  from  them  at 
each  systole ;  for  the  left  ventricle  is  very  frequently  found  quite  empty  after 
death ;  and  if  a  transverse  section  be  made  through  the  heart,  when  in  a  state 
of  well-marked  rigor  mortis  (which  may  be  considered  as  representing  its  ordi- 
nary state  of  complete  contraction),  the  ventricular  cavity  is  found  to  be  entirely 
obliterated.3     From  the  capacity  of  the  cavity  in  its  state  of  fullest  dilatation,  it 
can  scarcely  be  admitted  that  much  more  than  3  oz.  of  blood  can  be  propelled 
by  either  ventricle  at  each  systole ; 4  and  thus,  if  we  estimate  the  whole  amount 

1  See  the  « Report  of  the  Dublin  Committee  of  the  British  Association,'  loc.  cit. 

*  On  the  subject  of  the  Sounds  of  the  Heart,  the  various  treatises  on  Auscultation  and 
on  Diseases  of  the  Heart,  by  Williams,  Blakiston,  Hughes,  Walshe,  Davies,  Bellingham, 
Stokes,  Skoda,  Barth  and  Roger,  Weber,  and  others,  may  be  advantageously  consulted; 
see  also  the  account  of  Hamernjk's  investigations  in  the  "  Edinb.  Monthly  Journal, "  Jan., 
1849:  and  those  of  Kiwisch  in  the  "Brit  and  For.  Med.-Chir.  Rev.,"  April,  1852. 

3  Kirkes  and  Paget's  "  Handbook  of  Physiology,"  2nd  edit.,  p.  80,  Am.  Ed. 

*  The  total  quantity  discharged  from  either  ventricle  of  the  human  Heart  at  each  systole, 
is  estimated  by  Valentin  at  5-3  oz.,  and  by  Volkmann  at  6-2  oz. ;  but  these  accounts  are 


254  OF    THE    CIRCULATION    OF    THE    BLOOD. 

of  blood  at  18  Ibs.  (§  155),  this  would  require  96  strokes  for  its  passage  through 
either  side  of  the  heart ;  or,  reckoning  72  pulsations  to  a  minute,  the  time  elap- 
sing before  any  particle  could  return  to  a  given  point  after  once  passing  it  (sup- 
posing it  not  to  be  sent  elsewhere),  would  be  1£  minute.  Between  any  such 
estimates,  however,  and  those  which  are  founded  upon  experimental  inquiry  into 
the  time  required  for  the  passage  of  substances  introduced  into  the  circulating 
current  from  one  part  of  the  system  to  another,  there  is  a  discrepancy  which  it 
is  very  difficult  to  reconcile.  The  earliest  of  such  experiments  were  those  of 
Bering,1  who  endeavoured  to  ascertain  the  rapidity  of  the  circulation,  by  intro- 
ducing prussiate  of  potash  into  one  part  of  the  system,  and  drawing  blood  from 
another.  He  states  that  he  detected  this  salt,  in  blood  drawn  from  one  of  the 
jugular  veins  of  the  Horse,  within  20  or  30  seconds  after  it  had  been  introduced 
into  the  other ;  in  which  brief  space  the  blood  must  have  been  received  by  the 
heart,  must  have  been  transmitted  through  the  lungs,  have  returned  to  the  heart 
again,  have  been  sent  through  the  carotid  artery,  and  have  traversed  its  capil- 
laries. From  experiments  of  a  similar  nature  upon  other  veins,  he  states  that 
the  salt  passed  from  the  jugular  vein  into  the  saphena  in  20  seconds ;  into  the 
masseteric  artery,  in  from  15  to  20  seconds;  into  the  external  maxillary  artery, 
in  from  10  to  25  seconds ;  and  into  the  metatarsal  artery,  in  from  20  to  40 
seconds.2  These  experiments  have  been  fully  confirmed  by  those  of  Poisseuille,3 
and  also  by  those  of  Mr.  Blake;4  the  latter  of  whom  varied  them  by  employing 
different  substances,  and  took  other  precautions  against  sources  of  fallacy.  At 
an  interval  of  10  seconds  after  having  injected  a  solution  of  nitrate  of  baryta 
into  the  jugular  vein  of  a  horse,  he  drew  blood  from  the  carotid  artery  of  the 
opposite  side ;  after  allowing  this  to  flow  for  five  seconds,  he  substituted  another 
vessel,  which  received  the  blood  that  flowed  during  the  5  ensuing  seconds ;  and 
the  blood  that  flowed  after  the  20th  second,  by  which  time  the  action  of  the 
heart  had  stopped,  was  received  into  a  third  vessel.  These  different  specimens 
were  carefully  analysed.  No  trace  of  baryta  could  be  detected  in  the  blood 
which  had  escaped  from  the  artery  between  the  10th  and  the  15th  second  after 
the  injection  of  the  poison  •  but  in  that  which  was  drawn  between  the  15th  and 
the  20th  second,  the  salt  was  found  to  be  present,  and  in  greater  abundance  than 
in  the  blood  which  had  subsequently  flowed.  Moreover,  the  coincidence  between 
the  cessation  of  the  Heart's  action,  and  the  diffusion  of  the  salt  through  the 
arterial  blood,  bear  a  striking  correspondence ;  and  it  may  be  hence  inferred,  that 
the  arrestment  of  its  muscular  movement  is  due  to  the  effect  of  this  agent  upon 
its  tissue,  when  immediately  operating  upon  it,  through  the  capillaries  of  the 
coronary  artery.  —  This  conclusion  is  borne-out  by  a  variety  of  other  experi- 
ments; which  show  that  the  time  of  the  agency  of  other  poisons  that  suddenly 
check  the  Heart's  action  (which  is  the  especial  property  of  mineral  poisons), 
nearly  coincides,  in  different  animals,  with  that  which  is  required  to  convey  them 
into  the  arterial  capillaries.  And  it  seems  to  derive  full  confirmation  from  the 
fact,  that  poisons,  which  act  locally  on  other  parts,  give  the  first  indications  of 
their  operation,  in  the  same  period  after  they  have  been  introduced  into  the 
venous  circulation.  Thus,  in  the  Horse,  the  time  that  is  required  for  the  blood 
to  pass  from  the  jugular  vein  into  the  capillary  terminations  of  the  coronary  arte- 
ries, is  16  seconds,  as  is  shown  by  the  power  of  nitrate  of  potass  to  arrest 

deduced  from  calculation  of  the  (supposed)  total  of  the  blood,  divided  by  the  estimated 
duration  of  its  passage  through  the  heart,  rather  than  from  actual  admeasurement. 

1  "  Tiedemann's  Zeitschrift,"  vol.  iii.  p.  85. 

a  Although  attempts  have  been  made  to  invalidate  the  inference  which  seems  inevitably 
to  flow  from  these  experiments,  in  regard  to  the  rate  of  the  circulation,  by  attributing  the 
transmission  of  the  salt  to  the  permeability  of  the  animal  tissues,  yet  it  has  never  been 
shown  that  even  prussiate  of  potash  (which  is  probably  at  least  as  transmissible  through 
such  a  channel,  as  any  other  salt)  can  thus  find  its  way  from  one  part  to  another,  with  % 
rapidity  at  all  proportional  to  this. 

1  "Ann.  des  Sci.  Nat,"  1843,  Zool.,  torn.  xix.  p.  32. 

4  "  Edinb.  Med.  and  Surg.  Journal,"  Oct.,  1841. 


ACTION    OF    THE    HEART.  !>55 

the  Heart's  action  within  that  time;  and  nitrate  of  strychnia,  injected  into 
a  vein,  gave  the  first  manifestation  of  its  action  on  the  Spinal 'Cord,  in  pre- 
cisely the  same  number  of  seconds.  In  the  Dog,  the  heart's  action  was  arrested 
by  the  nitrate  of  potass  in  11  or  12  seconds;  and  the  tetanic  convulsions  occa- 
sioned by  strychnia,  also  commenced  in  12  seconds.  In  the  Fowl,  the  former 
period  was  6  seconds,  and  the  latter  6|-;  in  the  Rabbit,  the  first  was  4,  and  the 
other  4£  seconds. — From  such  experiments,  it  seems  evident  that  the  rapidity  of 
the  Circulation  is  underrated,  in  any  estimate  that  we  found  upon  the  capacity 
of  -the  Heart,  and  its  number  of  pulsations  in  a  given  time;  and  it  is  difficult  to 
see  how  the  two  sets  of  facts  are  to  be  reconciled. 

253.  The  force  with  which  the  systemic  Heart  propels  the  Blood,  may  be  es- 
timated in  two  ways;  —  either  by  ascertaining  the  height  of  the  column  of  that 
fluid,  which  its  contractile  action  will  support ;  —  or  by  causing  the  blood  to  act 
upon  a  shorter  column  of  mercury. — The  former  method  was  the  one  adopted  by 
Hales,  who  introduced  a  long  pipe  into  the  Carotid  artery  of  a  Horse,  and  found 
that  the  blood  would  sometimes  rise  in  it  to  the  height  of  10   feet.     From 
parallel  experiments  upon  Sheep,  Oxen,  Dogs,  and  other  animals,  and  from  the 
comparison  of  the  calibre  of  their  respective  vessels  with  that  of  the  Human 
aorta,  Hales  concluded  that  the  usual  force  of  the  Heart  in  Man  would  sustain  a 
column  of  blood  7J  feet  high,  the  weight  of  which  would  be  about  4  Ibs.  6  oz. 
—  The  second  method  is  that  which  was  adopted  by  Poisseuille ;  the  result  of 
whose  experiments  (made  with  the  instrument  which  he  termed  the  'hsemadyna- 
mometer')  corresponded  very  closely  with   that  of  Hales,  his  estimate  of  the 
pressure  of  blood  in  the  aorta  being  4  Ibs.  3  oz.     [The  instrument  of  Pois- 
seuille, slightly  modified  by  Volkmann  (Fig.  65),  consists  of  a  glass  tube  bent  so 
as  to  form  a  horizontal  (B")  and  two  perpendicular  (BB')  portions.     The  hori- 
zontal portion  is  capable  of  being  adapted  by  means  of  brass  tubes  of  various 
sizes  to  arteries  or  veins,  however  different  in  calibre.     The  tube  is  attached  to  a 
board  (A A'),  on  which  a  scale  is  marked.     To  use  it,  mercury  is  poured  into  the 
perpendicular  branches  of  the  tube,  and  will,  of  course,  stand  at  the  same  height 
in  each  when  the  instrument  is  kept  in  the  perpendicular. 

In  order  to  prevent  the  coagulation  of  the  blood,  which  by  causing  it  to  adhere 
to  the  sides  of  the  tube  would  complicate  the  experiment  (a  point  not  provided 
against  in  Hales's  experiments)  a  quantity  of  a  strong  solution  of  carbonate  of 
soda  is  poured  into  the  horizontal  branch,  and  will,  therefore,  rest  upon  the 
column  of  mercury  in  the  nearest  vertical  branch. 

The  instrument  is  now  adapted  by  means  of  a  pipe  provided  with  a  stopcock 
(F)  to  the  artery  in  which  the  blood  is  to  be  measured.  On  opening  the  stop- 
cock the  blood  rushes  into  the  horizontal  tube,  mingles  with  the  alkaline  solu- 
tion, and  pushes  down  the  mercury,  in  the  vertical  tube  B',  that  in  the  tube  B 
rising  to  the  same  extent  as  the  first  is  depressed.  The  rise  and  fall  of  the  mer- 
cury in  each  vertical  branch  can  be  measured  on  scales  placed  behind  them,  and 
as  the  rise  and  fall  are  equal,  the  double  of  either  will  give  the  height  of  a 
column  of  mercury  which  the  force  of  the  stream  of  blood  is  able  to  maintain. 
By  causing  the  blood  to  press  upon  a  column  of  mercury,  Poisseuille  got  rid  of 
the  necessity  of  having  a  very  long  tube,  as  used  by  Hales. — ED.]  The  more 
recent  experiments  of  Volkmann  '  have  led  him  to  nearly  the  same  conclusion ; 
notwithstanding  that  he  has  pointed-out  certain  fallacies  in  Poisseuille's  method. 
The  force  which  the  walls  of  the  Heart  must,  exert,  in  order  to  impart  such  a 
pressure  to  the  blood  which  they  propel,  is  properly  estimated  by  multiplying 
the  pressure  of  blood  in  the  aorta  by  the  ratio  between  the  area  of  that  trunk 
and  the  surface  of  a  plane  passing  through  the  base  and  apex  of  the  left  ventricle  ; 
which  method  of  computation  would  make  it  about  13  Ibs. 

254.  The  number  of  contractions  of  the  Heart  in  a  given  time  is  liable  to 
great  variation,  within  the  limits  of  ordinary  health,  from  several  causes ;  the 

1  "  Die  Hamodynamik  nach  Versuchen,"  Chap.  vn. 


256  OF    THE    CIRCULATION    OF    THE    BLOOD. 

[FiG.  65. 


Poisseuille's  Hsemadynamometer,  as  slightly  modified  by  Volkmann  : — AA',  the  board  to  which 
the  bent  glass  tube  (BB'B")  is  attached.  C'C",  a  thin  tube  which  is  fixed  through  a  cork  (D), 
air-tight  to  the  horizontal  branch  of  the  glass  tube.  E,  an  opening,  with  a  stopcock  in  this  tube. 
F,  a  conical  tube  which  may  be  introduced  into  an  artery  or  vein.  This  is  provided  with  a  stop- 
cock, which  serves  to  regulate  the  admission  of  the  blood  into  the  tube  of  the  haemadynamometer. 
GHG',  an  arm  of  wood  connected  with  the  board  which  serves  to  support  the  tin  tube,  and  so 
protect  the  horizontal  branch  of  the  glass  tube.] 

chief  of  these  are  diversities  of  Age,  of  Sex,  of  Stature,  of  Muscular  exertion, 
of  the  conditions  of  the  Mind,  of  the  state  of  the  Digestive  system,  and  of  the 
Period  of  the  day. 

a.  Putting  aside  the  other  causes  of  uncertainty,  the  following  table  may  be 
regarded  as  an  approximation  to  the  average  frequency  of  the  Pulse,  at  the  seve- 
ral Ages  specified  in  it,  taking  equal  numbers  of  Males  and  Females. 

Beats  per  Minute. 

In  the  foetus  in  utero 140  —  150 

Newly-born  infant 130  —  140 

During  the  1st  year 115  —  18C 

During  the  2nd  year 100  —  115 

During  the  3rd  year 95  —  105 

From  the  7th  to  the  14th  year 80—    90 

From  the  14th  to  the  21st  year 75  —    85 

From  the  21st  to  the  60th  year .". 70  —    75 

Old  age1 75—    80 

b.  The  difference  caused  by  Sex  is  very  considerable,  especially  in  adult  age ; 
it  appears  from  the  inquiries  of  Dr.  Guy,2  that  the  pulse  of  the  adult  Female  or- 

The  rise  in  the  average  frequency  of  the  pulse  in  very  advanced  life,  contrary  to  the 
prevalent  notion,  has  been  determined  by  the  observations  of  Leuret  and  Mitivie*  ("  De  la 
Frequence  des  Fouls  chez  les  Aliened"),  Dr.  Pennock  ("Amer.  Journ.  of  Med.  Sci.," 
July,  1847),  and  Prof.  Volkmann  (Op.  cit.  p.  427). 

a  "  Guy's  Hospital  Reports,"  vol.  iii.  p.  312 ;  and  "  Cyclop  of  Anat  and  Physiol."  vol. 
tv.,  Art.  « Pulse.' 


ACTION    OF    THE    HEART,  257 

dinarily  exceeds  in  frequency  the  pulse  of  the  adult  Male,  at  the  same  mean  age, 
by  from  10  to  14  beats  in  a  minute. 

c.  Many  of  the  observations  upon  the  effect  of  Stature  upon  the  pulse,  are  in- 
validated by  the  neglect  of  other  conditions  in  making  them ;  it  is  affirmed  by 
Volkmann,  however,  that  a  tolerably  definite  ratio  exists,1  the  pulse  being  caeteris 
paribus  less  frequent  as  the  stature  is  greater,  so  that  if  the  pulse  of  a  man  of 
5  i  feet  high  were  70  per  minute,  that  of  a  man  of  6  feet  would  be  66-7,  and 
that  of  a  man  of  5  feet,  73-8. 

d.  The  effect  of  Muscular  Exertion  in  raising  the  pulse  is  well  known ;  as  is 
also  the  fact,  which  is  one  exemplification  of  it,  that  the  pulse  varies  consider- 
ably with  the  posture  of  the  body.     The  amount  of  this  variation  has  been  made 
the  subject  of  extensive  inquiry  by  Dr.  Guy ;  and  the  following  are  his  results. 
In   100  healthy  Males,  of  the  mean  age  of  27  years,  in  a  state  of  rest,  the 
average  frequency  of  the  pulse  was,  when  standing  79,  when  sitting  70,  and 
when  lying  67,  per  minute.     Several  exceptions  occurred,  however,  to  the  gene- 
ral law ;  and  when  these  were  excluded,  the  average  numbers  were,  standing  81, 
sitting  71,  and  lying  66;  so  that  the  difference  between  standing  and  sitting  was 
10  beats,  or  l-8th  of  the  whole;  the  difference  between  sitting  and  lying  was  5 
beats,  or  l-13th  of  the  whole ;  and  the  difference  between  standing  and  lying 
was  15  beats,  or  l-5th  of  the  whole.     In  50  healthy  Females  of  the  same  mean 
age,  the  average  pulse  when  standing  was  89,  when  sitting  81,  and  when  lying 
80  ;  and  when  the  exceptions  (which  were  more  numerous  in  proportion  than  in 
males)  were  excluded,  the  averages  were,  standing  91,  sitting  84,  lying  79;  the 
difference  between  standing  and  sitting  was  thus  7  beats,  or  l-13th  of  the  whole ; 
that  between  sitting  and  lying  was  4,  or  l-21st  of  the  whole;  and  that  between 
standing  and  lying  was  11,  or  l-8th  of  the  whole.     In  both  sexes,  the  effect 
produced  by  change  of  posture  increases  with  the  usual  frequency  of  the  pulse ; 
whilst  the  exceptions  to  the  general  rule  are  more  numerous,  as  the  pulse  is  less 
frequent.     The  variation  is  temporarily  increased  by  the  muscular  effort,  involved 
in  the  absolute  change  of  the  posture ;  and  it  is  only  by  the  use  of  a  revolving 
board,  by  which  the  position  of  the  body  can  be  altered,  -without  any  exertion  on 
the  part  of  the  subject  of  the  observation,  that  correct  results  can  be  obtained. 
That  the  difference  between  standing  and  sitting  should  be  greater  than  that 
between  sitting  and  lying,  is  just  what  we  should  expect;  when  we  compare  the 
amount  of  muscular  effort  required  in  the  maintenance  of  the  two  former  posi- 
tions respectively. 

e.  The  pulse  is  well  known  to  be  much  accelerated  by  Menial  excitement,  es- 
pecially by  that  of  the  Emotions;  it  is  also  quicker  during  Digestion;  but  on 
neither  of  these  points  can  any  exact  numerical  statement  be  given. 

/.  The  diurnal  variation  of  the  Pulse,  has  been  made  the  subject  of  observa- 
tion by  Dr.  Knox2  and  Dr.  Guy;3  whose  inquiries  concur  to  disprove  the  usual 
notion  that  the  pulse  rises  towards  evening,  and  make  it  appear  that  the  more 
common  fact  is  the  reverse.  It  should  not  be  laid  down  as  a  general  rule,  how- 
ever, that  the  pulse  is  most  frequent  in  the  morning,  unless  it  be  also  stated  that 
the  exceptions  are  very  numerous.  For  whilst,  out  of  sixteen  healthy  young 
persons  of  both  sexes  examined  by  Dr.  Guy,  the  pulse  was  more  frequent  in  the 
morning  in  ten  individuals  by  from  2  to  18  beats  per  minute,  it  was  more  fre- 
quent in  the  evening  in  four  individuals  by  from  9  to  13  beats,  and  in  two  others 
there  was  no  difference.  Both  these  experimenters  have  remarked,  moreover, 
that  the  pulse  is  less  excitable,  as  well  as  less  frequent,  in  the  evening  than  in 

1  With  his  usual  zeal  for  formularization,  Volkmann  expresses  this  ratio,  as  deduced  from 
a  large  number  of  observations,  by  the  ratio  p  :  p/  =  A7|  .•  A|  (p  being  the  rate  of  the 
pulse,  and  h  the  height  of  the  body) ;  or,  in  other  words,  the  ratio  is  that  of  the  ninth  ,'oot 
of  the  fifth  power  of  the  height. — Surely  this  is  riding  a  hobby  to  the  death. 

a  "  Edinb.  Med.  and  Surg.  Journ.,"  vol.  xi.*"p.  53. 

*  "  Guy's  Hosp.  Rep.,"  vol.  iv.  p.  69. 
17 


2r         OF  THE  CIRCULATION  OF  THE  BLOOD. 

the  morning;  thus  it  was  found  by  Dr.  Guy,  that  the  very  same  food  which  in 
the  morning  increased  the  frequency  of  the  pulse  from  5  to  12  beats,  and  kept 
it  raised  above  its  natural  number  for  one  or  two  hours,  produced  no  effect  what- 
ever in  the  evening;  and  it  is  a  matter  of  ordinary  experience,  that  alcoholic 
liquors  have  a  much  more  potent  effect  upon  the  circulation  in  the  earlier  than 
in  the  latter  part  of  the  day. 


255.  The  Blood  propelled  from  the  Heart  is  distributed  to  the  body  in  gene- 
ral  by  a  system  of  Arteries,  which  may  be  likened  in  its  arrangement  to  the 
trunk  and  branches  of  a  tree,  except  that  very  frequent  communications  or  anas- 
tomoses exist  among  these  branches,  so  that,  by  contined  subdivision  and  inoscu- 
lation, their  distribution  comes  more  and  more  to  resemble  the  capillary  network 
in*which  they  terminate  (Fig.  66).  Although  the  diameters  of  the  branches 


FIG.  66. 


i 

Web  of  Frog's  foot,  stretching  between  two  toes,  magnified  3  diameters  :  sbowing  the  blood- 
vessels, and  their  anastomoses: — 1,  1,  veins;  2,  2,  2,  arteries. 

at  each  subdivision,  together  exceed  that  of  the  trunk,  yet  there  is  but  little  dif- 
ference in  their  respective  areas.  What  difference  does  exist,  however,  is 
usually  in  favour  of  the  branches ;  and  thus  it  happens  that  there  is  a  gradual 
increase  in  the  capacity  of  the  arterial  system  from  its  centre  towards  the  capil- 
laries, whose  capacity  is  many  times  greater  (§  263). — The  Arteries  exert  a  most 
important  influence  upon  the  movement  of  blood  through  them,  in  virtue  of  the 
physical  and  vital  properties  of  their  walls,  or  rather  of  their  middle  or  fibrous 
.oat,  which  alone  is  possessed  of  contractile  properties.  We  find  in  this  coat  a 
layer  of  yellow  Elastic  tissue,  which  is  much  thicker  in  the  larger  arteries,  in 
proportion  to  their  size,  than  in  the  smaller.  On  the  inside  of  this  is  a  layer  of 
annular  fibres,  composed  of  Muscular  fibre-cells,  mingled  with  areolar  tissue ; l 
the  muscular  element,  however,  is  much  more  abundant  in  the  smaller  arteries, 
than  in  the  larger.  To  the  former  tissue  is  due  the  simple  elasticity  of  the  arte- 
rial walls,  which  is  a  physical  property  that  persists  after  death,  until  a  serious 
change  takes  place  in  their  composition ;  whilst  to  the  latter  we  are  to  attribute 
the  property  which  they  unquestionably  possess  (in  common  with  proper  mus- 

1  See  Prof.  Eolliker's  "Manual  of  Human  Histology"  (Sydenham  Society's  Edit.),  vol. 
ti.  p  291. 


MOVEMENT    OF    THE    BLOOD    IN    THE    ARTERIES.      259 

eular  tissue),  of  contracting  on  the  application  of  a  stimulus,  so  long  as  their 
vitality  remains.  These  two  endowments  are  possessed  in  various  degrees,  pro- 
portional to  the  respective  predominance  of  the  elastic  or  of  the  muscular  tissue, 
by  the  different  parts  of  the  Arterial  system.  Thus,  as  was  justly  remarked  by 
Hunter,  the  elasticity,  being  the  property  by  which  the  interrupted  force  of  the 
Heart  is  made  equable  and  continuous,  is  most  seen  in  the  large  vessels  more  im- 
mediately connected  with  that  organ ;  whilst  on  the  other  hand,  the  contractility 
is  most  observable  in  the  smaller  vessels,  where  it  is  more  required  for  regulating 
the  flow  of  blood  towards  particular  organs. 

256.  It  has  been  denied  by  many  Physiologists,  that  the  middle  coat  of  the 
Arteries  possesses  any  property  that  can  be  likened  to  Muscular  Irritability ; 
but  no  reasonable  doubt  can  any  longer  exist  on  this  point.  Although  many  ex- 
perimenters have  failed  in  producing  contractions  of  their  walls  by  stimuli 
directly  applied  to  themselves,  yet  such  contractions  may  be  so  easily  demon- 
strated by  proper  means,  that  the  negative  results  cannot  be  admitted  as  invali- 
dating the  fact.  It  is  of  course  in  the  smaller  arteries,  that  the  evidence  of  this 
contractility  should  be  sought ,  and  this  may  be  readily  obtained  by  observing 
the  effects  of  various  stimuli,  mechanical,  chemical,  or  electrical,  upon  the  ves- 
sels of  a  transparent  membrane,  such  as  the  bat's  wing  or  the  frog's  foot.  Thus 
if,  whilst  we  watch  the  movement  of  blood  in  a  companion  artery  and  vein,  we 
draw  the  point  of  a  fine  needle  across  them  three  or  four  times,  without  appa- 
rently injuring  them  or  the  membrane  over  them,  they  will  both  presently  con- 
tract and  close ;  then,  after  remaining  for  a  few  minutes  in  the  contracted  state, 
they  will  begin  again  to  dilate,  and  will  gradually  increase  in  diameter  until  they 
acquire  a  larger  size  than  before  the  stimulus  was  applied.  When  in  this  con- 
dition, they  will  not  again  contract  on  the  same  stimulus  as  before;  the  needls 
may  now  be  drawn  across  them  much  oftener  and  more  forcibly,  but  no  contrac- 
tion ensues,  or  only  a  trivial  one,  which  is  quickly  followed  by  dilatation ;  with  a 
stronger  stimulus,  however,  such  as  that  of  great  heat,  they  will  again  contract 
and  close,  and  such  contraction  may  last  more  than  a  day,  before  the  vessels  again 
open  and  permit  the  flow  of  blood  through  them.1 — The  comparative  effects  of 
chemical  and  other  stimuli  have  recently  been  especially  studied  by  Mr.  Wharton 
Jones,2  by  whom  they  are  thus  classified.  (1).  Constriction  may  slowly  take 
place,  and  be  slowly  succeeded  by  the  normal  width ;  this  is  the  action  of  the 
sulphate  of  atropia.  (2.)  Constriction  may  quickly  take  place,  and  be  soon  suc- 
ceeded by  the  normal  width,  or  a  width  not  much  exceeding  the  normal ;  this  is 
the  result  of  the  moderate  application  of  cold,  and  of  mechanical  and  galvanic 
irritation.  (3).  Constriction  either  does  not  take  place  at  all,  or  when  it  does,  it 
very  rapidly  gives  place  to  great  dilatation ;  this  is  the  effect  of  a  weak  solution 
of  sulphate  of  copper,  of  a  strong  solution  of  common  salt,  of  wine,  of  opium, 
and  of  spirit  of  wine.  (4).  Dilatation,  preceded  or  not  by  momentary  constric- 
tion, may  slowly  yield  to  constriction,  which  remains  permanent;  this  is  the 
effect  of  sulphate  of  copper,  applied  in  strong  solution,  or  in  substance. — The 
electric  stimulus  is  most  effectual  when  applied  by  the  magneto-galvanic  appa- 
ratus; and  the  effects  of  such  application  have  been  investigated  by  the  Pro- 
fessors Weber.3  When  the  minute  arteries  of  the  mesentery  of  frogs,  between 
l-7th  and  l-17th  of  a  Paris  line  in  diameter,  were  thus  stimulated,  they  did  not 
immediately  respond  to  the  irritation,  but  began  to  contract  after  a  few  seconds, 

1  See  Mr.  Paget's  "Lectures  on  Surgical  Pathology,"  p.  181,  Am.  Ed.  —  As  Mr. 
Paget  justly  remarks,  it  is  from  the  mechanical  stimulus  of  the  knife,  that  small  divided 
vessels  contract  and  close,  so  as  speedily  to  cease  bleeding;  but  this  contraction  lasts  only 
for  a  time ;  and  haemorrhage  would  commence  on  their  dilatation,  if  their  mouths  were  not 
sealed  by  coagula  of  blood  or  lymph.  When  secondary  haemorrhage  does  occur  from  want 
of  such  coagulation,  it  is  most  effectually  controlled  by  the  application  of  such  stimuli  as, 
like  the  actual  cautery,  induce  a  more  prolonged  contraction  of  the  vessels. 

9  "Prize  Essay  on  Inflammation,"  in  "Guy's  Hospital  Reports"  for  1850,  pp.  8,  9. 

•  "  Muller's  Archiv.,"  1847. 

j 


260  OF    THE    CIRCULATION    OF    THE    BLOOD. 

so  that  their  diameter,  in  from  five  to  ten  seconds,  was  diminished  by  a  third,  and 
their  sectional  area  consequently  reduced  to  about  half;  by  a  continued  applica- 
tion of  the  stimulus,  their  calibre  was  so  much  reduced,  that  only  a  single  row 
of  corpuscles  could  pass ;  and  at  last  the  vessels  became  completely  closed,  and 
the  current  of  blood  arrested,  the  original  conditions  being  gradually  restored  on 
the  cessation  of  the  electric  current.  —  Further,  it  has  been  ascertained  by  the 
careful  experiments  of  Poisseuille  (which  confirm  those  of  John  Hunter),  that 
when  an  artery  is  dilated  by  fluid  injected  into  it,  it  reacts  with  a  force  superior 
to  the  distending  impulse  ;  and  he  has  also  shown  that,  if  a  portion  of  an  artery 
from  an  animal  recently  dead  (in  which  the  vital  contractility  seems  to  be  pre- 
served, and  one  from  an  animal  that  has  been  dead  some  days  (in  which  nothing 
but  the  elasticity  remains),  be  distended  with  an  equal  force,  the  former  becomes 
much  more  contracted  than  the  latter,  after  the  distending  force  is  removed. 

257.  Although  the  walls  of  the  Arteries  cannot  be  readily  stimulated  to  con- 
traction through  the  medium  of  their  nerves,  yet  the  influence  of  the  Nervous 
system  upon  the  calibre  of  the  vessels,  which  might  be  inferred  to  exist  from 
the  act  of  blushing  and  other  analogous  phenomena,  is  capable  of  experimental 
demonstration.     Thus,  Valentin  and  others  have  succeeded  in  producing  evident 
contractions  in  the  Aorta,  by  irritation   of  the   Sympathetic  nerve,  and  of  the 
roots  of  the  cervical  nerves  of  the  Spinal  system.     It  is  in  the  smaller  arteries, 
however,  that,  for  reasons  already  given  (§  255),  we  should  expect  to  find  the 
best  evidence  of  the  excitability  of  muscular  contraction  through  their  nerves. 
And  such  evidence  has  been  afforded  by  the  experiments  of  Dr.  Aug.  Waller, 
who  has  shown,  that  whilst  section  or  ligature  of   the  Sympathetic  trunk  on 
either  side  of  the  neck  produces  an  enlargement  of  the  minute  arteries  of  the 
cat  or  rabbit),  accompanied  with  an  elevation  of  temperature,  the  application  of 
galvanism  to  the  nerve  for  a  minute  or  less,  causes  them  to  contract  to  their 
ordinary  calibre.1 

258.  Several  experiments  also  indicate  the  existence  of  that  power  of  slow 
contraction  in  the  arteries,  which  has  been   distinguished  by  the  appellation 
Tonicity.     Thus,  when  a  ligature  is  placed  upon  an  artery  in  a  living  animal,  the 
part  of  the  artery  beyond  the  ligature  becomes  gradually  smaller,  and  is  emptied 
to  a  certain  degree,  if  not  completely,  of  the  blood  it  contained.     Again,  when 
part  of  an  artery  in  a  living  animal  is  isolated  by  means  of  two  ligatures,  and  is 
punctured,  the  blood  issues  from  the  orifice,  and  the  inclosed  portion  of  the 
artery  is  almost  completely  emptied  of  its  contents.     Further,  every  Surgeon 
knows,  that  the  contraction  of  divided  arteries  is  an  efficient  means  of  the  arrest 
of  haemorrhage  from  them,  especially  when  they  are  of  small  calibre;  so  that,  in 
the  case  of  the  temporal  artery  for  example,  the  complete  division  of  the  tube  is 
often  the  readiest  means  of  checking  the  flow  of  blood  from  it,  when  it  has  been 
once  wounded.     This  contraction  is  much  greater  than  could  be  accounted-for  by 
the  simple  elasticity  of  the  tissue ;  and  is  more  decided  in  small  than  in  large 
vessels.     The  empty  condition  of  the  arteries,  generally  found  within  a  short 
time  after  death,  seems  to  be  in  part  due  to  the  same  cause ;  since  their  calibre  is 
usually  much  diminished,  and  is  sometimes  completely  obliterated.     A  remark- 
able example  of  the  same  slow  contraction,  is  that  which  takes  place  in  the  end 
of  the  upper  portion  of  an  arterial  trunk,  when  the  passage  of  blood  through  it 
is  interrupted  by  a  ligature ;  for  the  current  of  blood  then  passes-off  by  the 
nearest  large  lateral  branch;    and  the  tube   of  the  artery  shrivels,  and  soon 
becomes  impervious,  from  the  point  at  which  the  ligature  is  applied,  back  to  the 
origin  of  that  branch.     This  last  fact  is  important,  as  proving  how  little  influence 
the  vis  a  tergo  possesses  over  the  calibre  of  arterial  tubes  ;  since,  without  any  in- 
terruption to  the  pressure  of  blood  occasioned  by  it,  the  tube  becomes  impervious. 

1  See  "Comptes  Rendus,"  1853,  torn,  xxxvi.  p.  378. — Of  this  remarkable  experiment, 
which  first  demonstrated  the  influence  of  the  Sympathetic  Nerve  upon  the  smaller  arteries, 
the  Author,  by  the  kindness  of  Dr.  Waller,  has  himself  been  a  witness. 


MOVEMENT    OF    THE    BLOOD    IN    THE    ARTERIES.      261 

It  is  to  the  moderate  action  of  the  tonicity  of  arteries,  that  their  contraction 
upon  the  stream  of  blood  passing  through  them  (which  serves  to  keep  the  tubes 
always  full)  is  due.  If  the  tonicity  be  excessive,  the  pulse  is  hard  and  wiry;  , 
but  if  it  be  deficient,  the  pulse  is  very  compressible,  though  bounding,  and  the 
flow  of  blood  through  the  arteries  is  retarded.  Dr.  C.  J.  B.  Williams  has  per- 
formed some  ingenious  experiments  (§  280),  which  prove  that  the  force  required 
to  propel  fluid  through  a  tube  whose  sides  are  yielding,  is  very  much  greater 
than  that  which  will  carry  it  through  a  tube  of  even  smaller  size,  with  rigid 
parietes ;  consequently  a  loss  of  tonicity  in  the  blood-vessels  retards  the  flow  of 
blood  through  them  ;  whilst  an  increase  hastens  it.  —  There  is  much  less  differ- 
ence between  the  Irritability  and  the  Tonicity  of  arteries,  than  between  the  like 
properties  in  ordinary  muscle ;  since  the  former  is  so  long  in  manifesting  itself, 
that  it  almost  approaches-  to  the  character  of  the  latter.  But  in  the  Arteries,  as 
in  other  muscles,  the  tonic  contraction  may  be  most  efficiently  induced  by  cold. 
Thus  Hunter  observed  that  the  exposure  of  an  artery  of  a  warm-blooded  animal 
to  the  air  for  some  time,  would  occasion  its  gradual  contraction  to  such  an  extent 
as  to  effect  the  obliteration,  of  its  canal.  This  statement  has  been  verified  by 
many  subsequent  experimenters;  and  it  has  also  been  confirmed  by  the  observa- 
tions of  Schwann  upon  the  small  arteries  of  the  mesentery  of  frogs,  which  he 
caused  to  contract  slowly  by  the  application  of  cold  water,  and  then  saw  dilate 
again ;  as  much  as  half  an  hour  being  required,  however,  before  they  recovered 
their  original  size.  On  the  other  hand,  the  application  of  moderate  warmth 
causes  a  relaxation  of  this  tonic  contraction.  —  And  thus  Cold  and  Heat  are  two 
of  our  most  valuable  remedial  agents,  when  the  Tonicity  of  the  Vascular  system 
is  deficient  or  in  excess. 

259.  We  have  now  to  inquire  more  closely  into  the  influence  exerted  by  the 
vital  and  physical  properties  of  the  walls  of  the  Arteries,  upon  the  motion  of 
Blood  through  them. — There  is  no  sufficient  proof  that  the  vital  Contractility  of 
these  vessels  enables  them  to  exert  a  propulsive  action  in  any  degree  supple- 
mentary to  that  of  the  Heart;  and  yet,  looking  to  the  general  facts  already 
stated,  as  to  the  diffusion  of  the  propulsive  power  through  the  arterial  trunks  in 
many  of  the  lower  animals  (§  234),  and  their  experimentally-proved  reaction 
upon  a  distending  force  (§  256),  it  does  not  seem  by  any  means  improbable  that 
some  such  power  should  be  preserved,  even  where  there  is  the  greatest  concen- 
tration of  the  propulsive  force  in  the  muscular  walls  of  the  heart. — The  contrac- 
tility of  the  arteries  seems  to  be  chiefly  exercised,  however,  in  regulating  the 
diameter  of  the  tubes,  in  accordance  with  the  quantity  of  blood  to  be  conducted 
through  them  to  any  part;  which  will  depend  upon  its  peculiar  circumstances  at 
the  time.  Such  local  changes  are  continually  to  be  observed,  in  the  various 
phases  of  normal  life,  as  well  as  in  diseased  states ;  and  they  will  be  found  to  be 
constantly  in  harmony  with  the  particular  condition  of  the  processes  of  Nutrition, 
Secretion,  &c.,  to  which  the  capillary  circulation  ministers.  In  such  cases,  it 
cannot  be  the  action  of  the  Heart  that  increases  the  calibre  of  the  vessels;  since 
this  is  commonly  unaltered,  and  is  itself  unable,  as  we  have  just  seen,  even  to 
maintain  their  permeability,  when  their  contractility  is  excited.  It  must,  there- 
fore, be  by  a  power  operating  directly  through  themselves,  that  their  dilatation 
is  effected.  The  minute  distribution  of  the  Sympathetic  nerve  upon  the  walls 
of  the  arteries,  the  known  power  which  this  has  of  producing  contractions  in 
their  fibrous  coat  (§  257),  and  the  influence  of  mental  states  upon  their  dimen- 
sions (as  shown  in  the  phenomena  of  blushing  aud  erection),  render  it  highly 
probable  that  the  calibre  of  the  arteries  is  regulated  in  no  inconsiderable  degree 
"through  its  intervention.  The  permanent  enlargement,  however,  which  is  seen 
in  the  arteries  supplying  parts  that  are  in  a  state  of  active  increase,  must  be  due, 
not  to  simple  dilatation  merely,  but  to  augmented  nutrition ;  since  we  find  that 
their  walls  are  thickened  as  well  as  extended.  And,  on  the  other  side,  when 
slow  contraction  occurs  in  these  tubes  as  a  consequence  of  disease,  it  must  be  in 


262  OF    THE    CIRCULATION     OF    THE    BLOOD. 

part  occasioned  by  atrophy;  since  their  nutrition  is  so  much  diminished,  that  in 
time  they  almost  entirely  disappear, — a  portion  of  a  large  artery  shrivelling  into 
a  ligamentous  band. 

260.  The  purpose  served  by  the  Elasticity  of  the  Arteries,  is  one  of  a  purely 
physical  character;  its  effect  being  to  convert  the  intermitting  impulses,  which 
the  blood  receives  from  the  heart,  into  a  continuous  current.  The  former  are 
very  evident  in  the  larger  trunks ;  but  they  diminish  with  the  subdivision  of 
these,  until  they  entirely  disappear  in  the  capillaries,  in  which  the  stream  is 
usually  equable  or  nearly  so.  If  a  powerful  force-pump  were  made  to  inject 
water,  by  successive  strokes,  into  a  system  of  tubes  with  unyielding  walls,  the 
flow  of  fluid  at  the  farther  extremities  of  these  tubes  would  be  as  much  inter- 
rupted as  its  entrance  into  them.  But  if  an  air-vessel  (like  that  of  a  fire-engine) 
were  placed  at  their  commencement,  the  flow  would  be  in  a  great  degree  equal- 
ized ;  since  a  part  of  the  force  of  each  stroke  would  be  spent  upon  the  compres- 
sion of  the  air  included  in  it ;  and  this  force  would  be  restored  by  the  elasticity 
of  the  air  during  the  interval,  which  would  propel  the  stream,  until  directly  re- 
newed by  the  next  impulse.  A  much  closer  imitation  of  the  natural  apparatus 
would  be  aflbrded  by  a  pipe  which  had  elastic  walls  of  its  own ;  thus  if  water 
were  forced  by  a  syringe  into  a  long  tube  of  caoutchouc,  for  example,  the  stream 
would  be  equalized  before  it  had  proceeded  far.  This  effect  is  found  to  be  ac- 
complished, at  any  point  of  the  Arterial  circulation,  in  a  degree  proportionate  to 
its  distance  from  the  Heart ;  and  in  this  mode  it  is,  that  the  intermitting  force 
of  the  ventricular  contraction  is  almost  equably  distributed  over  the  whole  of 
the  interval  between  one  systole  and  another,  by  the  contraction  of  the  elastic 
tubes  in  the  dilatation  of  which  it  was  at  first  expended. — Another  effect  of  this 
elasticity  is  to  distribute  the  pressure  of  the  blood  upon  the  walls  of  the  arteries, 
much  more  equally  than  would  be  the  case  if  they  formed  a  system  of  rigid 
tubes.  For,  according  to  Volkmann,1  since  the  lateral  pressure  of  a  liquid 
moving  through  tubes  of  uniform  calibre  with  rigid  walls,  is  proportional  to  the 
resistance  to  be  overcome  at  each  point,  and  since  this  resistance  depends  upon 
the  adhesion  and  friction  between  the  liquid  and  the  parietes  of  the  tube,  the 
lateral  pressure  at  each  point  will  vary  inversely  with  the  distance  of  that  point 
from  the  discharging  orifice.  Consequently,  if  the  arteries  constituted  a  system 
of  rigid  tubes,  the  pressure  on  their  walls  would  decrease  very  rapidly,  in  passing 
from  the  heart  towards  their  peripheral  extremities.  Such,  however,  is  far  from 
being  the  case ;  for  although  the  pressure  is  by  no  means  equal  throughout 
(§  263),  yet  it  does  not  vary  in  any  such  ratio. 

261.  The  distension  of  the  Arteries  that  is  consequent  upon  the  intermittent 
injection  of  blood  into  their  trunks,  and  the  subsequent  contraction  which  results 
from  the  elasticity  of  their  walls,  give  rise  to  the  pulsation  which  is  perceptible 
to  the  touch  in  all  but  the  smallest  arteries,  and  which  is  visible  to  the  eye  when 
they  are  exposed.  This  pulsation  involves  an  augmentation  of  the  capacity  of 
that  portion  of  the  artery  in  which  it  is  observed ;  and  it  would  seem  to  the 
touch,  as  if  this  were  chiefly  effected  by  an  increase  of  diameter.  It  has  been 
experimentally  proved,  however,  that  the  increased  capacity  is  partly  given  by  the 
elongation  of  the  artery,2  which  is  lifted  from  its  bed  at  each  pulsation,  and, 

*  «Hamodynamik,"p.  38. 

a  The  experiments  of  Volkmann  have  led  him  to  believe,  that  the  transverse  dilatation 
is  greater  than  the  longitudinal;  but  these  experiments  were  made  under  conditions  so 
different  from  those  of  the  living  artery,  that  but  little  weight  can,  in  the  Author's  opinion, 
be  attached  to  them.  It  is  to  be  remembered,  however,  that  every  increase  in  length 
augments  the  capacity  in  only  a  simple  ratio ;  thus  a  tube  of  21  inches  in  length  will  only 
contain  one-twentieth  more  than  a  tube  of  20  inches  long,  of  the  same  diameter.  On  the 
other  hand,  every  increase  in  diameter  augments  the  capacity  of  the  tube  in  the  ratio  of 
the  square  of  that  increase  :  thus  the  capacity  of  a  tube  of  21  lines  in  diameter  will  be  to 
that  of  a  tube  of  20  lines,  as  441  :  400,  or  one-tenth  more.  Consequently,  supposing  the 
increase  of  capacity  to  take  place  equally  in  both  directions,  the  increase  in  longitudinal 
dimension  will  be  far  more  apparent  than  the  transverse  enlargement. 


MOVEMENT     OF    THE    BLOOD    IN    THE    ARTERIES.       263 

when  previously  straight,  becomes  curved  ;  the  impression  made  upon  the  finger 
by  such  displacement,  not  being  distinguishable  from  that  which  would  result 
from  the  dilatation  of  the  tube  in  diameter.  A  very  obvious  example  of  this 
upheaval  is  seen  in  the  prominent  temporal  artery  of  an  old  person.  The  total 
increase  of  capacity  was  estimated  by  Flourens,  from  experiments  upon  the  caro- 
tid artery,  at  about  l-23rd  part;  but  it  is  affirmed  by  Yolkmann  (Op.  cit.,  chap. 
xiv.)  that  this  must  not  be  considered  by  any  means  a  constant  ratio,  since  it 
varies  in  different  arteries,  and  in  the  same  artery  under  different  circumstances. 
—  The  distension  of  the  arteries  does  not  take  place  at  the  same  moment  over 
the  whole  body,  but  is  propagated  as  a  'wave  from  the  commencement  to  the 
point  of  discharge.  The  passage  of  this  wave  was  considered  by  Prof.  E.  H. 
Weber  to  be  distinct  from  the  act  of  propulsion  of  the  fluid ;  but  it  has  been 
shown  by  Volkmann  (Op.  cit.,  chap,  x.)  that  they  are  one  and  the  same.  He 
has  further  shown  that  two  systems  of  waves  arise,  when  a  fluid  is  driven  through 
an  elastic  tube  by  intermitting  impulses;  one  of  these  being;  in  the  fluid,  and 
the  other  in  the  walls  of  the  tube.  These  may  propngate  themselves  with  dif- 
ferent velocities,  and  thus  two  undulations  may  result  from  one  impulse.  This 
want  of  coincidence  between  the  two  waves'  is  probably  the  explanation  of  the 
dichrotous  pulse,  often  observable  in  convalescence  from  fevers  and  other  diseases 
after  the  subsidence  of  vascular  excitement. — That  a  certain  time  is  required  for 
the  transmission  of  the  pulse-wave  from  the  heart  to  the  periphery  of  the  circu- 
lation, is  proved  by  the  want  of  synchronism  between  the  ventricular  systole, 
and  the  pulsation  of  the  arteries  in  various  parts  of  the  body ;  the  difference 
varying  according  to  their  distance  from  the  heart.  A  considerable  diversity  in 
the  amount  of  this  interval  is  observable  in  different  states  of  the  arterial  system ; 
for,  as  Dr.  C.  J.  B.  Williams  has  pointed-out.1  when  the  tonicity  is  in  excess,  the 
arteries  approach  the  condition  of  rigid  bones,  and  the  pulse  at  the  wrist  is 
almost  exactly  synchronous  with  the  heart's  beat;  whilst,  if  the  tonicity  be 
defective,  the  radial  pulse  is  felt  at  a  long  interval  after  the  heart's  beat,  and  the 
difference  is  still  more  perceptible  when  the  pulse  is  examined  in  the  feet.  The 
longest  interval  in  a  state  of  health  seems  to  be  between  l-6th  and  l-7th  of  a 
second. 

262.  The  rate  of  movement  of  the  blood  in  the  Arteries  can  only  be  guessed- 
at,  as  regards  the  Human  subject,  from  the  comparative  results  of  experiments 
upon  the  lower  animals.  It  is  stated  by  Volkmann  (Op.  cit.,  p.  196)  that  the 
average  velocity  of  the  current  in  the  carotids  of  a  considerable  number  of  Mam- 
mals which  he  examined,  was  about  300  milliin.,  or  nearly  12  inches,  per  second; 
that  the  velocity  is  greater  in  the  arteries  lying  near,  than  in  those  at  a  distance 
from  the  heart;  that  it  is  not  increased  by  an  augmentation  in  the  number  of 
pulsations  ;2  but  that  it  is  greatly  augmented  by  an  increase  in  the  volume  of  the 

1  "Principles  of  Medicine,"  3d  Am.  Edit.,  p.  75.  — Dr.  Williams  mentions,  -what  the 
Author  has  himself  noticed,  that  the  radial  pulse,  in  cases  of  deficient  tonicity,  is  some- 
times felt  after  the  second  sound  of  the  heart  is  heard  ;  a  fact,  that  negatives  the  doctrine 
of  the  pulse  put  forward  by  Mr.  Colt  ("Medical  Gazette,"  vol.  xxxvi.  p.  456),  which  was 
founded  on  the  assumption  that  the  pulse  is  perceived  in  every  part  of  the  arterial  system 
previously  to  the  occurrence  of  the  second  sound  of  the  heart,  that  is,  before  the  closure 
of  the  aortic  valves.  The  Author  has  a  very  distinct  recollection  of  a  case  which  he  wit- 
nessed when  a  student  in  the  Middlesex  Hospital,  in  which  the  radial  pulse,  though  ac- 
tually synchronous  with  the  heart's  beat,  was  really  dependent  upon  the  preceding  ventri- 
cular systole ;  the  whole  of  the  interval  between  one  systole  and  another  being  required 
for  the  transmission  of  the  pulse-wave  from  the  heart  to  the  wrist,  as  was  proved  by 
tracing  it  from  the  centre  towards  the  periphery  of  the  arterial  system.  Now  in  this  case, 
if  the  marked  want  of  synchronism  between  the  pulse  at  the  wrist  and  in  the  neck  b;id 
not  excited  attention,  the  synchronism  between  the  radial  pulse  arid  the  heart's  beat 
would  have  passed  as  an  ordinary  occurrence,  instead  of  being  a  very  extraordinary  phe- 
nomenon. 

a  On  this  very  important  point  the  observations  of  Volkmann  are  in  full  accordance 
with  the  results  of  some  of  Hering's  experiments  performed  with  special  reference  to  it 
(I  252). 


264 


OF  THE  CIRCULATION  OF  THE  BLOOD. 


blood,  and  lessened  by  its  diminution.  [The  instrument  devised  by  Volkrnann, 
and  which  he  calls  the  hcvmodrometer,  consists  of  a  glass  tube,  fifty-two  inches 
long,  bent  into  the  form  of  a  hair-pin,  and  containing  water,  which  is  substituted 
for  a  segment  of  the  blood-vessel,  in  which  it  is  required  to  measure  the  velocity 
of  the  blood's  stream.  The  column  of  blood  which  comes  from  the  heart  pushes 
the  column  of  water  before  it,  without  any  great  mixture  of  the  two  fluids  taking 
place,  and  in  passing  through  a  determined  space  it  takes  a  measureable  time, 
whence  it  may  be  calculated  how  far  the  blood  moves  in  a  second. 

The  following  description  will  explain  the  instrument  and  the  mode  of  using 
it.     At  4  (Fig.  67)  is  a  metal  tube,  an  inch  and  a  half  in  length;  the  ends  of 

FIG.  67. 


this  (a  «')  are  conical,  and  fit  into  two  corresponding  conical  tubes  (k,  &'),  made 
like  the  pipes  of  an  injecting  syringe,  so  that  they  can  be  readily  fitted  into  an 
nrtery.  A  stopcock  (&')  commands  the  channel  of  this  tube,  not  only  at  a',  but 
also  by  two  cogged  wheels,  at  a.  The  mechanism  of  this  arrangement  may  be 
readily  understood,  by  reference  to  the  adjoining  sections  of  the  portion  of  the 
instrument  at  B  and  C,  and  the  view  of  its  other  surface  at  D  (r,  r  D).  At 
'/.  h'  are  two  short  tubes,  also  of  metal,  which  are  fitted  into  the  horizontal  tube 
below  the  stopcock,  and  so  that  their  channels  (as  shown  at  C)  may  communi- 


MOVEMENT    OF    THE    BLOOD    IN    THE    ARTERIES.      265 

cate  with,  and  be  exactly  equal  to,  that  of  the  horizontal  tube.  The  stopcock 
(£/)  commands  this  communication  likewise.  These  short  tubes  (A,  #)  fit 
exactly  upon  the  bent  glass  tube  Q>,  p\  and  complete  the  communication  be- 
tween its  channel,  and  that  of  the  horizontal  tube  at  its  extremities.  When  the 
stopcock  is  turned  so  as  to  open  the  channel  of  the  horizontal  tube  throughout, 
as  at  B,  all  communication  with  the  glass  tube  is  cut  off:  on  the  other  hand, 
when  the  communication  with  the  glass  tube  is  opened,  as  at  C,  the  channel  of 
the  horizontal  tube  is  stopped,  and  fluid  entering  at  a',  would  have  to  pass 
through  A',  and  to  traverse  both  limbs  of  the  glass  tube  (p,  p)  emerging  at  a. 
For  the  protection  of  the  instrument  in  using  it,  the  glass  tube  is  attached  to  a 
board,  to  which  is  fixed  a  scale  marked  in  metal. 

In  order  to  use  the  instrument,  a  large  artery  is  freely  exposed  for  not  less 
than  three  inches,  and,  after  due  precaution  has  been  taken  to  counteract  haemor- 
rhage, it  is  divided  by  cutting  out  a  piece ;  the  conical  tubes  (&,  &')  are  then 
fixed  into  the  open  ends  of  the  artery,  one  being  directed  towards  the  heart,  the 
other  towards  the  capillaries.  They  must  be  fixed  far  enough  apart,  to  admit  of 
the  introduction  of  the  horizontal  tube  (A)  between  them,  without  altering  the 
usual  direction  of  the  arterial  stream.  When  this  tube  is  fitted  to  the  conical 
pipe,  then  the  bent  glass  tube,  previously  filled  with  water,  must  be  fixed  to  it 
by  means  of  the  short  tubes  (A,  h',  C),  the  stopcock  being  so  turned  as  to  shut  off 
all  communication  with  the  glass  tube.  As  soon  as  the  instrument  has  been 
properly  fixed  in  the  artery,  the  blood  is  allowed  to  flow  into  the  glass  tube.  It 
may  be  now  seen  to  traverse  the  glass  tube  with  a  velocity  very  nearly  the  same 
as  it  has  in  the  artery,  and  in  doing  so,  it  pushes  the  water  before  it  into  the 
peripheral  blood-vessels,  with  (according  to  Volkmann)  only  a  very  slight  admix- 
ture between  the  two  fluids. 

By  trials  made  with  his  hsemodrometer,  Volkmann  found,  in  the  case  of  seven 
dogs,  that  the  blood  flowed  in  their  carotids  with  a  velocity  ranging  between 
205  and  357  millimetres  in  a  second;  in  that  of  horses,  306  to  234;  in  the 
metatarsal  artery  of  the  horse,  56,  and  in  the  maxillary  artery  of  the  same  animal, 
99  ;  in  the  carotid  of  a  calf,  431.  The  average  velocity  in  the  carotids  of  mam- 
mals is  stated  by  Volkmann  to  be  300 '  millimetres  in  a  second.2  —  ED.]  It 
appears  from  the  observations  of  the  Profrs.  Weber  already  referred-to  (§  256), 
that  the  velocity  undergoes  a  marked  increase  in  branches  of  arteries  whose 
diameter  has  been  diminished  by  the  contraction  of  their  walls,  the  acceleration 
being  proportionate  to  the  narrowing  of  the  tube,  as  might  a  priori  be  expected; 
a  gradual  retardation  took  place  with  the  return  of  the  artery  to  the  original 
diameter;  and  when,  as  sometimes  happened,  the  vessel  dilated  to  more  than  its 
former  dimensions,  a  positive  diminution  in  the  rate  of  movement  in  the  blood 
was  observable. 

263.  The  lateral  pressure  of  the  blood  against  the  walls  of  the  arteries  was 
affirmed  by  Poisseuille  to  be  equal  throughout  the  whole  arterial  system ;  but 
the  more  accurate  experiments  of  Volkmann  (made  with  Ludwig's  '  kymogra- 
phion,'  which  is  a  far  more  trustworthy  instrument  than  the  *  hsemadynamorneter' 
of  Poisseuille)  have  shown  that  this  statement  is  far  from  being  correct.  The 
pressure  of  the  blood,  he  remarks,  is  no  constant  magnitude,  but  is  incessantly 
changing  according  to  the  stroke  of  the  heart,  the  movements  of  respiration,  and 
the  muscular  actions  of  the  body  generally.  A  gradual  diminution  of  its 
amount,  however,  may  be  nearly  constantly  traced  from  the  commencement  of  the 
arterial  to  the  termination  of  the  venous  system  \  and  this  is  to  be  partly  ac- 
counted-for  by  the  increase  in  the  calibre  of  the  vascular  system,  which  takes 
place  as  we  pass  from  the  arterial  trunks  to  their  ramifications  (§  255),  and  still 
more  from  the  arterial  to  the  venous  system  (§  277) ;  and  partly  by  the  diminu- 

1  Tolerably  close  approximations  to  the  value  of  these  measurements  in  English  inches, 
may  be  obtained  by  dividing  each  number  by  25. 

a  '•  Todd  and  Bowman's  Physiological  Anatomy,"  Am.  Ed. 


266 


OF  THE  CIRCULATION  OF  THE  BLOOD. 


tion  of  resistance  (which  is  the  essential  cause  of  the  lateral  pressure)  as  the 
blood  moves-onwards  towards  its  point  of  discharge  (§  260).  The  following 
table  presents  the  results  of  Volkmann's  observations  (Op.  cit.  p.  173)  upon  the 
relative  lateral  pressure  at  four  points  of  the  circulation  in  different  animals, 
namely  (i.)  the  carotid  near  its  origin  (n.)  a  peripheral  branch  of  the  carotid  or 
some  other  artery  (in.)  a  peripheral  rootlet  of  a  vein,  and  (iv.)  the  jugular 
vein : — 

i.  n.  iji.  IT. 

Goat 135  126  41  18 

Horse 122  97  44  21-5 

Calf 165-5  146  27-5  9 

A  blood-pressure  equivalent  to  a  column  of  mercury  160  millim.  (6-3  inches)  in 
height,  was  assumed  by  Poisseuille  as  the  standard  for  all  arteries  and  for  all 
Mammalia,  and  therefore  (by  inference)  for  Man.  It  has  been  shown  by 
Ludwig  and  Volkmann,  however,  that  the  range  of  variation  is  very  wide,  being 
in  the  carotid  of  the  Horse  from  150  to  321,  and  being  not  less  in  other  ani- 
mals. Hence  it  is  obvious  that  no  precise  specification  can  be  laid-down  upon 
this  point. 

4.  Movement  of  the  Blood  in  the  Capillaries. 

264.  In  Man,  as  in  all  the  higher  Animals, — in  the  adult  condition  at  least, 
—  the  Capillary  circulation  is  almost  entirely  carried-on  through  tubes  having 
distinct  membranous  parietes ;  the  only  known  exception  being  in  the  case  of 
the  Spleen  (§  142).  These  tubes  commonly  form  a  minutely-anastomosing  net- 
work (Fig.  68);  into  which  the  blood  is  brought  by  the  ramifications  of  the  arte- 

FIG.  68. 


Capillary  plexus  in  a  portion  of  the  web  of  a  Frog's  foot,  magnified  110  diameters  : — 1,  trunk 
of  vein;  2,  2,  its  branches;  3,  3,  pigment-cells. 

ries  on  one  side,  and  from  which  it  is  returned  by  the  radicles  of  the  veins  on 
the  other.  The  walls  of  the  tubes  are  composed  of  a  delicate  membrane,  in 
which  an  appearance  of  transverse  striation  (as  if  produced  by  minute  annular 
fibres)  can  sometimes  be  discerned ;  they  contain  nothing,  however,  that  is  in  the 
least  degree  comparable  to  any  form  of  muscular  fibre.  Bodies  having  the  ap- 


MOVEMENT    OF    THE    BLOOD     IN    THE    CAPILLARIES.      267 

pearance  of  cell-nuclei  may  frequently  be  seen  in  the  walls  of  the  capillaries  of 
embryos  and  of  tadpoles ;  and  these  are  too  wide  apart  to  warrant  the  idea,  that 
they  are  the  nuclei  of  epithelial  cells,  such  as  those  which  line  the  larger  vessels. 
Similar  nuclei  may  be  brought  into  view  in  the  capillaries  of  adult  animals,  by 
treating  them  with  acetic  acid ;  and  they  are  particularly  well  seen  in  the  Pia 
Mater,  which  consists  almost  entirely  of  a  congeries  of  blood-vessels  (Fig.  69.) 

FIG.  69. 


Capillary  Blood-vessels  from  Pia  Mater :— te,  calibre  of  the  tube,  partly  occupied  by  oval  nu- 
clei, alternately  arranged  lengthways,  and  epithelial  in  their  character ;  b,  b,  b,  nuclei  projecting 
on  the  exterior  of  the  tube ;  c,  c,  walls,  and  d,  calibre,  of  a  large  branch;  /,/,  oval  nuclei,  ar- 
ranged transversely.  Magnified  410  diameters. 

The  accompanying  figure  shows  the  contrast  between  the  long  oval  nuclei  5,  b, 
imbedded  at  intervals  in  the  walls  of  the  true  capillaries,  and  rather  projecting 
on  their  exterior;  and  the  nuclei  of  the  epithelium-cells,/,/,  lining  the  interior 
of  a  large  branch,  which  last  are  more  numerous  and  of  less  regular  form,  and 
are  sometimes  placed  transversely  to  the  direction  of  the  tube.  The  diameter 
of  the  Capillaries  varies  in  different  animals,  in  accordance  with  that  of  their 
blood-corpuscles ;  thus  the  Capillaries  of  the  Frog  are,  of  course,  much  larger 
than  those  of  Man.  The  ordinary  diameter  of  the  latter  appears,  from  the 
measurements  of  Weber,  Miiller,  and  others,  to  vary  from  the  l-3700th  to  the 
l-2500th  of  an  inch ;  the  extremes,  however,  are  stated  by  Kolliker  at  as  little 
as  l-5600th  and  as  much  as  l-1870th  of  an  inch.  As  the  diameter  of  the 
Human  capillaries,  however,  can  only  be  examined  after  death,  it  is  probable  that 
these  statements  may  not  be  altogether  exact,  particularly  as  tubes  of  the  smallest 
of  the  above  sizes  would  not  admit  ordinary  blood-corpuscles.  The  dimensions 
of  the  individual  vessels,  indeed,  are  by  no  means  constant ;  as  may  be  seen  by 
watching  the  Circulation  in  any  transparent  part,  for  some  little  time.  Putting 
aside  the  general  changes  in  diameter,  which  result  from  circumstances  affecting 
all  the  capillaries  of  a  part,  it  may  be  observed  that  a  single  capillary  will  some- 
times enlarge  or  contract  by  itself,  without  any  obvious  cause.  Thus,  the  stream 
of  blood  will  sometimes  be  seen  to  run  into  passages,  which  were  not  before  per- 
ceived ;  and  it  has  hence  been  supposed  that  they  were  new  excavations,  formed 
by  the  retreating  or  removal  of  the  solid  tissue  through  which  it  passes.  But  a 
more  attentive  examination  shows,  that  such  passages  are  real  capillaries,  which 
did  not,  at  the  time  of  the  first  observation,  admit  the  stream  of  blood-corpuscles, 


268 


OF  THE  CIRCULATION  OF  THE  BLOOD. 


in  consequence  of  the  contraction  of  their  calibre,  or  of  some  other  local  impedi 
ment;  and  that  they  are  brought  into  view  by  the  simple  increase  in  their 
diameter.  The  compression  of  one  of  the  small  arteries  will  generally  occasion 
an  oscillation  of  the  corpuscles  of  blood  in  the  smallest  capillaries,  which  will  be 
followed  by  the  disappearance  of  some  of  them ;  but  when  the  obstruction  is 
removed,  the  blood  soon  regains  its  previous  velocity  and  force,  and  flows  into 
exactly  the  same  passages  as  before. 

265.  The  opinion  was  long  entertained,  that  there  are  vessels  adapted  to 
supply  the  white  or  colourless  tissues ;  carrying  from  the  arteries  the  i  liquor  san- 
guinis/  and  leaving  the  corpuscles  behind,  through  inability  to  receive  them. 
But  such  a  supposition  is  altogether  groundless.  Some  of  the  white  tissues,  as 
Cartilage,  are  altogether  destitute  of  vessels  j  and  in  others,  the  supply  of  blood 
is  so  scanty,  as  not  to  communicate  to  them  any  decided  hue.  The  idea  that 
Nutrition  can  only  be  carried-on  by  means  of  Capillary  vessels,  is  entirely  gra- 
tuitous j  for  there  is  no  essential  difference  between  the  nutrition  of  the  non-vas- 
cular tissues,  and  that  of  the  islets  in  the  midst  of  the  network  of  capillary 
vessels  which  traverses  the  most  vascular.  In  both  cases,  the  nutrient  materials 
conveyed  by  the  blood  are  absorbed  by  the  cells  or  other  elementary  parts  of  the 
tissue  immediately  adjoining  the  vessels,  and  are  imparted  by  them  to  others 
which  are  further  removed ;  and  the  only  difference  lies  in  the  amount  of  the 
portion  of  tissue  which  has  to  be  thus  traversed,  so  that  we  are  only  required  to 
extend  our  ideas,  from  the  largest  of  the  islets  which  we  find  in  the  vascular 
tissues,  to  the  still  more  isolated  structures  of  which  the  non-vascular  tissues  are 
composed.  — The  disposition  of  the  Capillaries,  both  as  to  the  degree  of  minute- 
ness and  the  plan  of  reticulation  which  they  form,  vary  so  greatly  in  the  different 
vascular  tissues,  that  it  is  possible  to  state  with  tolerable  certainty  the  nature  of 
the  part,  from  which  any  specimen  has  been  detached, — whether  a  portion  of  skin 
(Fig.  70),  mucous  membrane  (Fig.  71),  serous  membrane,  muscle  (Fig.  72), 
nerve,  fat  (Fig.  73),  areolar  tissue,  gland  (Fig.  17),  &c.  The  degree  of  minute- 


FIG.  70. 


FIG.  71. 


Distribution  of  Capillaries  on  the  surface 
of  the  Skin  of  the  finger. 

FIG.  72. 


Distribution  of  Cupil/ariev  around  follicle* 
of  Mucous  Membrane. 

FIG.  73. 


Distribution  of  Capillaries  in  Muscle. 


Capillary  net- work  around  Fat-cells. 


ness  is  obviously  in  accordance  with  the  copiousness  of  the  supply  of  blood  whicl* 
is  required  for  the  purposes  of  its  circulation  through  the  part;  thus  the  plexus 
is  closest,  where  some  change  is  to  be  effected  on  the  blood  itself,  as  in  the  ab 


MOVEMENT    OF    THE    BLOOD    IN    THE    CAPILLARIES.     '269 

sorbent,  respiratory,  and  secreting  organs;  whilst  it  is  widest  in  those  parts 
which  receive  the  blood  solely  for  their  own  nutrition, — the  nervous  centres  and 
muscles  having  a  more  minute  reticulation  than  is  seen  in  the  generality  of  the 
last-named  parts,  in  virtue  of  the  peculiar  activity  of  the  molecular  changes 
which  take  place  in  them.  But  the  arrangement  of  vessels  peculiar  to  each,  evi- 
dently has  reference  only  to  the  convenience  of  the  distribution  of  blood  among 
the  elementary  parts  of  the  tissue,  and  varies  with  their  form.  It  is  not  possible 
to  imagine  that  it  has  any  other  relation  than  this  to  their  function ;  since  the 
function  of  each  separate  element  of  the  organ,  of  which  that  of  the  entire 
organ  is  the  aggregate,  is  due  to  its  own  inherent  vital  powers,  —  the  supply  of 
blood  being  only  required,  as  furnishing  the  material  on  which  these  are  to  be 
exercised. 

266.  The  average  rate  of  movement  of  the  blood  through  the  capillary  system, 
maybe  determined  with  tolerable  precision  by  microscopic  measurement;  and 
the  observations  of  Hales,  Valentin  and  Weber  concur  in  representing  it  to  be 
from  1  inch  to  1^  inch  per  minute  in  the  systemic  capillaries  of  the  Frog;  1-2 
inch  per  minute,  or  -02  inch  per  second,  being  about  the  average.     In  warm- 
blooded animals,  however,  the  capillary  circulation  is  probably  much  more  rapid 
than  this;  the  observations  of  Volkmann  upon  the  mesenteric  arteries  of  the 
Dog  make  its  rate  about  -03  inch  per  second,  or  1-8  inch  per  minute;  and  it 
seems  reasonable  to  suppose  that  the  exposure  of  the  membrane  to  the  cool  air 
would  produce  a  considerable  reduction  in  the  normal  rapidity  of  the  flow  of 
blood  through  it.     Assuming  -03  inch  per  second,  however,  as  the  rate,  and  com- 
paring this  with  the  rate  of  movement  of  the  blood  in  the  larger  arteries,  which 
seems  on  the  average  to  be  11-8  inches  per  second,  it  is  calculated  by  Volkmann 
that  the  aggregate  area  of  the  capillaries  (being  in  an  inverse  ratio  to  the  rate  of 
the  blood's  movement  through  them)  must  be  nearly  four  hundred  times  that  of 
the  arterial  trunks  which  supply  them.1 

267.  That  the  movement  of  the  Blood  through  the  Capillary  system  of  ves- 
sels, is  mainly  dependent  upon  the  force  which  it  derives  from  the  Heart  and 
from  the  coats  of  the  Arteries,  is  a  matter  altogether  beyond  dispute.     But  it  is 
a  most  important  question,  not  merely  in  itself,  but  in  its  bearing  on  one  of  the 
fundamental  questions  of  Pathology, — the  nature  of  Inflammation, — whether  the 
Capillary  circulation  is  influenced  by  any  oilier  agency  than  the  contractile  powei 
of  the  Heart  and  Arterial  system ;  some  Physiologists  maintaining,  that  this 
alone  is  sufficient  to  account  for  all  the  phenomena  of  the  Capillary  circulation ; 
and  others  asserting,  that  it  is  necessary  to  admit  some  supplementary  force, 
which  may  be  exerted  either  to  assist,  retard,  or  regulate  the  flow  of  blood  from 
the  Arteries  into  the  Veins.     We  shall  first  consider  the  evidence  which  may 
justify  an  affirmative  conclusion  as  to  the  existence  of  such  force;  and  shall  then 
examine  into  its  nature.  —  No  physiological  fact  seems  to  the  Author  to  be  more 
clearly  proved,  than  the  existence,  in  the  lower  classes  of  Animals,  as  well  as  in 
Plants,  of  some  power  independent  of  a  vis  d  tergo,  by  which  the  nutritive  fluid 
is  caused  to  move  through  their  vessels.2     This  power  appears  to  originate  in  the 
circulation  itself,  and  to  be  closely  connected  with  the  state  of  the  Nutritive  and 
Secreting  processes  :  since  anything  which  stimulates  these  to  increased  energy, 
accelerates  the  movement ;  whilst  any  check  to  them  occasions  a  corresponding 
stagnation.     It  may  be  convenient  to  designate  this  motor  force,  by  the  name  of 
capillary  power ;  it  being  clearly  understood,  however,  that  no  mechanical  pro- 
pulsion is  thence  implied.     On  ascending  the  Animal  scale,  we  find  the  power 
which,  in  the  lower  organisms,  is  diffused  through  the  whole  system,  gradually 
concentrated  in  a  single  part;  a  new  force,  that  of  the  Heart,  being  brought  into 
operation,  and  the  Circulation  placed,  in  a  greater  or  less  degree,  under  its  con- 
trol.    Still  there  is  evidence,  that  the  movement  of  blood  through  the  capillaries 

1  "  Hamodynamik,"  pp.  184,  204. 

*  See  "  Princ.  of  Comp.  Phys.,"  chap,  v.,  Am.  Ed. 


270  OF    THE    CIRCULATION    OF    THE    BLOOD. 

is  not  entirely  due  to  this ;  since  it  may  continue  after  the  cessation  of  the  Heart's 
action,  may  itself  cease  in  particular  organs  when  the  Heart  is  still  acting 
vigorously,  and  is  constantly  being  affected  in  amount  and  rapidity,  by  causes 
originating  in  the  part  itself,  and  in  no  way  affecting  the  Heart.  —  The  chief 
proofs  of  these  statements  will  now  be  adverted-to. 

268.  When  the  flow  of  blood  through  the  Capillaries  of  a  transparent  part, 
such  as  the  web  of  a  Frog's  foot,  is  observed  with  the  Microscope,  it  appears  at 
first  to  take  place  with  great  evenness  and  regularity.     But  on  watching  the 
movement  for  some  time,  various  changes  may  be  observed,  which  cannot  be  at- 
tributed to  the  Heart's  influence,  and  which  show  that  a  certain  regulating  or 
distributive  power  exists  in  the  walls  of  the  capillaries,  or  in  the  tissues  which 
they  traverse.     Some  of  these  changes,  involving  variations  in  the  size  of  the 
capillary  tubes,  have  been  already  referred-to  (§  264).     Others,  however,  are 
manifested  in  great  and  sudden  alterations  in  the  velocity  of  the  current ;  which 
cause  a  marked  difference  in  the  rates  of  the  movement  of  the  blood,  through 
the   several   parts    of  the  area   under  observation.     Sometimes   this  variation 
extends  even  to  the  entire  reversal  for  a  time,  of  the  direction  of  the  movement, 
in  certain  of  the  transverse  or  communicating  branches;  the  flow  always  taking 
place,  of  course,  from  the  stronger  towards  the  weaker  current.     Not  unfre- 

.quently,  an  entire  stagnation  of  the  current  in  some  particular  tube,  precedes 
this  reversal  of  its  direction.  Irregularities  of  this  kind,  however,  are  more 
frequent  when  the  Heart's  action  is  partly  interrupted ;  as  it  usually  is  by  the 
pressure  to  which  the  tadpole  or  other  animal  must  be  subjected,  in  order  to  allow 
microscopic  observations  to  be  made  upon  its  circulation.  Under  such  circum- 
stances, the  varieties  in  the  capillary  circulation,  induced  by  causes  purely  local, 
become  very  conspicuous;  for  when  the  whole  current  is  nearly  stagnated,  and  a 
fresh  impulse  from  the  heart  renews  it,  the  movement  is  not  by  any  means  uni- 
form (as  it  might  have  been  expected  to  be)  through  the  whole  plexus  supplied 
by  one  arterial  trunk,  but  is  much  greater  in  some  of  the  tubes  than  it  is  in 
others;  the  variation  being  in  no  degree  connected  with  their  size,  and  being 
very  different  at  short  intervals. 

269.  The  movement  of  the  blood  in  the  Capillaries  of  cold-blooded  animals, 
after  complete  excision  of  the  Heart,  has  been  repeatedly  witnessed.     In  warm- 
blooded animals,  this  cannot  be  satisfactorily  established  by  experiment,  since 
the  shock  occasioned  by  so  severe  an  operation  much  sooner  destroys  the  general 
vitality  of  the  system ;  but  it  may  be  proved  in  other  ways  to  take  place.     After 
most  kinds  of  natural  death,  the  arterial  system  is  found,  subsequently  to  the 
lapse  of  a  few  hours,  almost  or  completely  emptied  of  blood ;  this  is  partly,  no 
doubt,  the   effect  of  the  tonic  contraction   of  the  tubes  themselves;  but  the 
emptying  is  commonly  more  complete  than  could  be  thus  accounted-for,  and  must 
therefore  be  partly  due  to  the  continuance  of  the  capillary  circulation.     It  has 
been  observed  by  Dr.  Bennet  Dowler,1  that  in  the  bodies  of  individuals  who  have 
died  from  yellow  fever,  the  external  veins  frequently  became  so  distended  with 
blood  within  a  few  minutes  after  the  cessation  of  the  heart's  action,  that,  when 
they  are  opened,  the  blood  flows  in  a  good  stream,  being  sometimes  projected  to 
the  distance  of  a  foot  or  more,  especially  when  pressure  is  applied  above  the 
puncture,  as  in  ordinary  blood-letting.     It  is  not  conceivable  that  the  slowly- 
acting  tonicity  of  the  arteries  should  have  produced  such  a  result  as  this ;  which 
can  scarcely,  therefore,  be  attributed  to  anything  else  than  the  sustenance  of  the 
capillary  circulation  by  forces  generated  within  itself.     Further,  it  has  been  well 
ascertained  that  a  real  process  of  secretion  not  unfrequently  continues  after  gene- 
ral or  somatic  death ;  urine  has  been  poured-out  by  the  ureters,  sweat  exuded 
from  the  skin,  and  other  peculiar  secretions  formed  by  their  glands ;  and  these 
changes  could  scarcely  have  taken  place,  unless  the  capillary  circulation  were  still 

1  "  Researches,  Critical  and  Experimental,  on  the  Capillary  Circulation,  reprinted  from 
the  "New  Orleans  Medical  and  Surgical  Journal,"  Jan.  1849. 


MOVEMENT    OF    THE    BLOOD    IN    THE    CAPILLARIES.     271 

continuing.  In  the  early  embryonic  condition  of  the  highest  animals,  the  move- 
ment of  blood  seems  to  be  unquestionably  due  to  some  diffused  power,  independ- 
ent of  any  central  impulsion ;  for  it  may  be  seen  to  commence  in  the  Vascular 
Area,  before  it  is  subjected  to  the  influence  of  the  Heart.  The  first  movement 
is  towards,  instead  of  from-,  the  centre;  and  even  for  some  time  after  the  circu- 
lation has  been  fairly  established,  the  walls  of  the  Heart  consist  merely  of  cells 
loosely  attached  together,  and  can  hardly  be  supposed  to  have  any  great  contrac- 
tile power. 

270.  The  last  of  these  facts  maybe  said  not  to  have  any  direct  bearing  on  the 
question,  whether  the  'capillary  power '  has  any  existence  in  the  adult  condition; 
but  the  phenomena  occasionally  presented  by  the  foetus,  at  a  later  stage,  appear 
decisive.     Cases   are  of  no  very  unfrequent  occurrence,  in  which   the  heart  is 
absent  during  the  whole  of  embryonic  life,  and  yet  the  greater  part  of  the  organs 
are  well  developed.     In  most  or  all  of  these  cases,  it  is  true,  a  perfect  twin  fostus 
exists,  of  which  the  placenta  is  in  some  degree  united  with  that  of  the  imperfect 
one ;  and  it  has  been  customary  to  attribute  the  circulation  in  the  latter  to  the 
influence  of  the  heart  of  the  former,  propagated  through  the  placental  vessels. 
This  supposition  had  not  been  disproved  (however  improbable  it  might  seem), 
until  a  case  of  this  kind  occurred,  which  was  submitted  to  the  most  careful  ex- 
amination by  an  accomplished  anatomist;1  when  the  decisive  result  was  obtained, 
that  it  seemed  impossible  for  the  heart  of  the  twin-fo3tus  to  have  occasioned  the 
movement  of  blood  in  the  imperfect  one,  and  that  some  cause  present  in  the 
latter  must  have  been  sufficient  for  the  propulsion  of  blood  through  its  vessels. 
It  was  a  very  curious  anomaly  in  this  case,  that  the  usual  functions  of  the  arteries 
and  veins  must  have  been  reversed ;  for  the  Vena  Cava,  receiving  its  blood  from 
the  umbilical  vein  nearly  as  usual,  had  no  communication  with  the  Arterial 
system  (the  Heart  being  absent),  except  through  the  systemic  capillaries;  to 
which,  therefore,  the  blood  must  have  next  proceeded,  returning  to  the  placenta 
by  the  umbilical  artery.     This  view  of  the  course  of  the  blood  was  confirmed  by 
the  fact,  that  the  veins  were  everywhere  destitute  of  valves. — It  is  evident  that  a 
single  case  of  this  kind,  if  unequivocally  demonstrated,  furnishes  all  the  proof 
that  can  be  needed,  of  the  existence,  even  in  the  highest  animals,  of  a  *  capillary 
power;'  which,  though  usually  subordinate  to  the  Heart's  action,  is  sufficiently 
strong  to  maintain  the  circulation  by  itself,  when  the  power  of  the  central  organ 
is  diminished.     In  this,  as  in  many  other  cases,  we  may  observe  a  remarkable 
capability  in  the  living  system,  of  adapting  itself  to  exigencies.     In  the  acardiac 
Foatus,  the  '  capillary  power'  supplies  the  place  of  the  Heart,  up  to  the  period 
of  birth ;  after  which,  of  course,  the  circulation  ceases,  for  want  of  due  aeration 
of  the  blood.     It  has  occasionally  been  noticed,  that  a  gradual  degeneration  in 
the  structure  of  the  Heart  has  taken-place  during  life,  to  such  an  extent  that 
scarcely  any  muscular  tissue  could  at  last  be  detected  in  it,  but  without  any  such 
interruption  to  the  circulation  as  must  have  been  anticipated,  if  this  organ  fur- 
nishes the  sole  impelling  force. 

271.  Further,  it  is  a  general  principle,  unquestioned  by  any  Physiologist,  and 
embodied  in  the  ancient  aphorism  Ufa  stimulus,  Hi  fluxus,  that,  when  there  is 
any  local  excitement  to  the  processes  of  Nutrition,  Secretion,  &c.,  a  determination 
of  blood  towards  the  part  speedily  takes  place,  and  the  motion  of  blood  through 
it  is  increased  in  rapidity;  and  although  it  might  be  urged,  that  this  increased 
determination  may  not  be  the  effect,  but  the  cause,  of  the  increased  local  action, 
such  an  opinion  could  not  be  sustained  without  many  inconsistencies  with  posi- 
tive facts.     For  it  is  known  that  such  local  determinations  may  take  place,  not 

1  See  Dr.  Houston  in  the  "Dublin  Medical  Journal,"  1837.  — An  attempt  was  made  by 
Dr.  M.  Hall  ("Edinb.  Monthly  Journal,"  1843)  to  disprove  Dr.  Houston's  inferences; 
but  a  most  satisfactory  reply  was  given  by  Dr.  Houston,  at  the  Meeting  of  the  British 
Association,  August,  1843,  and  published  in  the  "  Dublin  Journal,"  Jan.,  1844.  Sec  also 
"Edinb.  Med.  and  Surg.  Journ.,  July,  1844. 


272       OF  THE  CIRCULATION  OF  THE  BLOOD. 

only  as  a  part  of  the  regular  phenomena  of  growth  and  development  (as  in  the 
case  of  the  entire  genital  system  at  the  time  of  puberty  and  of  periodical  heat, 
the  uterus  after  conception,  and  the  mammae  after  parturition),  but  also  as  a  con- 
sequence of  a  strictly  local  cause.  Thus,  the  student  is  well  aware  that,  after 
several  hours'  close  application,  there  is  commonly  an  increased  determination  of 
blood  to  the  brain,  causing  a  sense  of  oppression,  a  feeling  of  heat,  and  fre- 
quently a  diminished  action  in  other  parts ;  and,  again,  when  the  capillary  circu- 
lation is  being  examined  under  the  microscope,  it  is  seen  to  be  quickened  by 
moderate  stimuli,  and  to  be  equally  retarded  by  depressing  agents.  All  these 
facts  harmonize  completely  with  the  phenomena,  which  are  yet  more  striking  in 
the  lower  classes  of  organized  beings,  and  which  are  evidently  in  accordance  with 
the  same  laws. 

272.  It  is  equally  capable  of  proof,  on  the  other  hand,  that  an  influence  gene- 
rated in  the  Capillaries  may  afford  a  complete  check  to  the  circulation  in  the 
part;  even  when  the  Heart's  action  is  unimpaired,  and  no  mechanical  impedi- 
ment exists  to  the  transmission  of  blood.     Thus,  cases  of  spontaneous  Gangrene 
of  the  lower  extremities  are  of  no  unfrequent  occurrence,  in  which  the  death  of 
the  solid  tissues  is  clearly  connected  with  a  local  decline  of  the  circulation ;  and 
in  which  it  has  been  shown  by  examination  of  the  limb  after  its  removal,  that 
both  the  larger  tubes  and  the  capillaries  were  completely  pervious ;  so  that  the 
cessation  of  the  flow  of  blood  could  not  be  attributed  to  any  impediment,  except 
that  arising  from  the  cessation  of  some  power  which  exists  in  the  capillaries,  and 
which  is  necessary  for  the  maintenance  of  the  current  through  them.     The  in- 
fluence of  the  prolonged  application  of  Cold  to  a  part,  may  be  quoted  in  support 
of  the  same  general  proposition ;  for,  although  the  calibre  of  the  vessels  may  be 
diminished  by  this  agent,  yet  their  contraction  is  not  sufficient  to  account  for 
that  complete  cessation  of  the  flow  of  blood  through  them,  which  is  well  known 
to  occur,  and  to  terminate  in  the  loss  of  their  vitality.     The  most  remarkable 
evidence  on  this  point,  however,  is  derived  from  the  phenomena  of  Asphyxia, 
which  will  be  more  fully  explained  in  the  succeeding  Chapter  (§§  326,  327).     At 
present  it  may  be  stated  as  a  fact,  which  has  now  been  very  satisfactorily  ascer- 
tained, that,  if  admission  of  air  into  the  lungs  be  prevented,  the  circulation 
through  them  will  be  brought  to  a  stand,  as  soon  as  the  air  which  they  contain 
has  been  to  a  great  degree  deprived  of  its  oxygen,  or  rather  has  become  loaded 
with  carbonic  acid ;  and  this  stagnation  will,  of  course,  be  communicated  to  all 
the  rest  of  the  system.     Yet,  if  it  have  not  continued  sufficiently  long  to  cause 
the  loss  of  vitality  in  the  nervous  centres,  the  movement  may  be  renewed  by  the 
admission  of  air  into  the  lungs.     Now  although  it  has  been  asserted,  that  the 
stagnation  is  due  to  a  mechanical  impediment,  resulting  from  the  contracted  state 
of  the  lungs  in  such  cases,  this  has  been  clearly  proved  not  to  be  the  fact,  by 
causing  animals  to  breathe  a  gas  destitute  of  oxygen,  so  as  to  produce  Asphyxia 
in  a  different  manner;  for  the  same  stagnation  results,  as  in  the  other  case. 

273.  If  the  phenomena  which  have  been  here  brought  together,  be  considered 
as  establishing  the  existence,  in  all  classes  of  beings  possessing  a  circulating 
apparatus,  of  a  '  Capillary  power/  which  affords  a  necessary  condition  for  the 
movement  of  the  nutritious  fluid,  through  those  parts  in  which  it  comes  into 
more  immediate  relation  with  the  solids,  the  question  still  remains  open,  what  is 
the  nature  of  that  power.  —  It  is  very  doubtful  whether  the  Capillaries  possess 
true  contractility;  for  although  their  diameter  is  subject  to  great  variation,  yet 
this  may  be  due  simply  to  the  elasticity  of  their  walls,  which  tends  to  keep  them 
constantly  contracted  upon  the  stream  of  blood  that  passes  through  them ;  and 
there  is  no  adequate  proof  that  the  alterations  in  their  size,  which  are  consequent 
upon  the  local  application  of  stimuli,  proceed  from  any  other  source  than   the 
alteration  in  the  quantity  of  blood  delivered  to  them  by  the  minute  arteries,  the 
very  considerable  alterations  in  whose  calibre  under  such  influences  have  been 
already  described  (§§  256,  257).     In  the  experiments  of  the  Profrs.  Weber  (loc. 


MOVEMENT    OF    THE    BLOOD     IN    THE     CAPILLARIES.      273 

cit.),  the  application  of  the  electric  stimulus  to  the  capillaries  produced  no  change 
in  their  diameter.  Even  supposing  the  capillaries,  however,  to  possess  such  an 
independent  contractility,  this  could  not  exert  itself  in  aiding  the  flow  of  blood 
through  them,  except  either  by  rhythmical  alternations  of  contraction  and  dila- 
tation, or  by  some  kind  of  peristaltic  movement;  and  observation  completely 
(negatives  the  idea  of  the  existence  of  any  such  movement,  since  the  stream  of 
blood,  now  rendered  continuous  by  the  elasticity  of  the  arteries,  passes  through 
the  capillaries  as  through  tubes  of  glass.  Hence  the  notion  of  any  mechanical 
assistance,  afforded  by  the  action  of  the  walls  of  the  Capillaries  to  the  movement 
of  blood  through  them,  must  be  altogether  dismissed. 

274.  There  is  experimental  evidence,  however,  that  the  movement  of  the 
blood  may  be  affected  by  any  agency  which  alters  the  cnemico-vital  relations 
between  the  blood  and  the  tissues  which  it  permeates.  Thus,  when  the  inter- 
rupted electric  current  was  applied  to  the  capillaries  by  the  Profrs.  Weber,  they 
noticed  that  the  blood-corpuscles  showed  a  remarkable  tendency  to  adhere  to  each 
other  and  to  the  walls  of  the  vessels,  so  as  to  produce  a  great  amount  of  friction 
and  a  consequent  retardation  ;  the  continual  arrival  of  new  corpuscles  thus  pro- 
duces an  accumulation  which  completely  fills  the  vessels  of  the  part,  and  thus 
occasions  a  total  stagnation ;  but  this  gives  place  to  the  renewal  of  the  current 
by  the  dispersion  of  the  corpuscles,  soon  after  the  withdrawal  of  the  stimulus. 
A  very  similar  set  of  phenomena  has  been  observed  by  Mr.  Wharton  Jones,1  as 
the  consequence  of  the  direction  of  a  stream  of  carbonic  acid  against  the  capil- 
lary network.  And  the  depression  of  the  vitality  of  the  part,  by  such  injuries 
as  tend  to  excite  Inflammation  in  it,  produces  a  like  stagnation.  This  effect 
cannot  be  attributed  to  mechanical  obstruction  in  the  vessels,  for  they  are  usually 
dilated  rather  than  contracted,  when  this  condition  exists;  and  without  any 
change  in  the  dimensions  of  a  tube,  the  stream  of  blood  through  it  may  be  seen 
decreasing  from  extreme  velocity  to  complete  stagnation.2  —  That  alternations  in 
the  chemical  state  of  the  blood  (involving,  of  course,  important  changes  in  its 
vital  properties)  are  capable  of  exercising  a  most  important  effect  on  the  Capillary 
circulation,  is  shown,  not  merely  by  the  stagnation  of  the  pulmonary  Circulation 
in  Asphyxia  (§  327),  but  by  the  curious  fact  ascertained  by  Dr.  J.  Reid,3  that 
the  blood,  when  imperfectly  arterialised,  is  retarded  in  the  systemic  capillaries, 
causing  an  increased  pressure  on  the  walls  of  the  arteries.  He  found  that,  when 
the  ingress  of  air  through  the  trachea  of  a  Dog  was  prevented,  and  the  Asphyxia 
was  proceeding  to  the  stage  of  insensibility,  —  the  attempts  at  inspiration  being 
few  and  laboured,  and  the  blood  in  an  exposed  artery  being  quite  venous  in  its 
character, — the  pressure  upon  the  arterial  walls,  as  indicated  by  the  haemadyna- 
mometer  applied  to  the  femoral  artery,  was  much  greater  than  usual.  Upon 
applying  a  similar  test  to  a  vein,  however,  it  was  found  that  the  pressure  was 
proportionably  diminished ;  whence  it  became  apparent,  that  there  was  an  un- 
usual obstruction  to  the  passage  of  venous  blood  through  the  systemic  capillaries. 
After  this  period,  however,  the  mercury  in  the  haemadynamometer  applied  to  the 
artery  began  to  fall  steadily,  and  at  last  rapidly,  in  consequence  of  the  dimi- 
nished force  of  the  heart,  and  the  retardation  of  the  blood  in  the  pulmonic  capil- 
laries ;  but,  if  atmospheric  air  was  admitted,  the  mercury  rose  instantly,  showing 
that  the  renewal  of  the  proper  chemical  state  of  the  blood  restored  the  condition 
necessary  for  its  circulation  through  the  capillaries.4 

1  "Brit,  and  For.  Med.  Review,"  vol.  xiv.  p.  600. 

a  See  Mr.  Paget,  Op.  cit.  p.  311. — The  Author  had  long  previously  satisfied  himself  that 
such  was  the  fact ;  and  is  glad  to  be  able  to  cite  the  far  more  extended  observations  of 
Mr.  Paget  on  this  point,  in  confirmation  of  his  own. 

3  "  Edinb.  Med.  and  Surg.  Journ.,"  April,  1841 ;  and  "  Anat.,  Phys.,  and  Pathol,  Re- 
searches," chap.  ii. 

*  This  last  fact  (as  Dr.  Reid  has  remarked)  is  sufficient  to  negative  the  idea  of  Mr. 
Erich  sen,  that  the  obstruction  is  caused  by  the  contraction  of  the  capillaries  under  the 

18 


274  OF    THE    CIRCULATION    OF    THE    BLOOD. 

275.  It  appears  from  the  preceding  facts,  that  the  conditions  under  which  the 
power  in  question  uniformly  operates,  may  be  thus  simply  and  definitely  ex- 
pressed :  Whilst  the  injection  of  blood  into  the  Capillary  vessels  of  every  part 
of  the  system,  is  due  to  the  action  of  the  Heart,  its  rate  of  passage  through  those 
vessels  is  greatly  modified  by  the  degree  of  activity  in  the  processes,  to  which  it 
should  normally  be  subservient  in  them;  — the  current  being  rendered  more 
rapid  by  an  increase  in  their  activity,  and  being  stagnated  by  their  depression  or 
total  cessation.  Or  at  any  rate,  to  use  the  more  guarded  language  of  Mr.  Paget 
(loc.  cit.),  we  have  facts  enough  to  justify  the  hypothesis,  "  that  there  is  some 
mutual  relation  between  the  blood  and  its  vessels,  or  the  parts  around  them, 
which,  being  natural,  permits  the  most  easy  transit  of  the  blood,  but,  being  dis- 
turbed, increases  the  hindrances  to  its  passage." — A  physical  principle  has  been 
put-forth  by  Prof.  Draper,1  which  seems  quite  adequate  to  explain  these  pheno- 
mena.— It  appears  fully  capable  of  proof,  that  "  if  two  liquids  communicate  with 
one  another  in  a  capillary  tube,  or  in  a  porous  or  parenchymatous  structure,  and 
have  for  that  tube  or  structure  different  chemical  affinities,  movement  will  ensue ; 
that  liquid  which  has  the  most  energetic  affinity  will  move  with  the  greatest 
velocity,  and  may  even  drive  the  other  liquid  before  it."  Now  Arterial  blood, — 
3ontaining  oxygen  with  which  it  is  ready  to  part,  and  being  prepared  to  receive 
in  exchange  the  carbonic  acid  which  the  tissues  set  free, — must  obviously  have  a 
greater  affinity  for  those  tissues,  than  Venous  blood,  in  which  both  these  changes 
have  already  been  effected.  Consequently,  upon  mere  physical  principles,  the 
arterial  blood  which  enters  the  Systemic  capillaries,  must  drive  before  it,  and 
expel  on  the  other  side  of  the  network,  the  blood  which  has  become  venous 
whilst  traversing  it;  but  if  the  blood  which  enters  the  capillaries  have  no  such 
affinity,  no  such  motor  power  can  be  developed. — On  the  other  hand,  in  the  Pul- 
monary capillaries  the  opposite  affinities  prevail.  The  venous  blood  and  the  air 
in  the  cells  of  the  lungs  have  a  mutual  attraction,  which  is  satisfied  by  the  ex- 
3hange  of  oxygen  and  carbonic  acid  that  takes  place  through  the  walls  of  the 
capillaries;  and  when  the  blood  has  become  arterialised,  it  no  longer  has  any 
attraction  for  the  air.  Upon  the  very  same  principle,  therefore,  the  venous  blood 
will  drive  the  arterial  before  it,  in  the  pulmonary  capillaries,  whilst  respiration  is 
properly  going-on  :  but  if  the  supply  of  oxygen  be  interrupted,  so  that  the  blood 
is  no  longer  aerated,  no  change  in  the  affinities  takes  place  whilst  it  traverses  the 
capillary  net-work ;  the  blood  continuing  venous,  still  retains  both  its  need  of  a 
change,  and  its  attraction  for  the  walls  of  the  capillaries;  and  its  egress  into  the 
pulmonary  veins  is  thus  resisted,  rather  than  aided,  by  the  force  generated  in  the 
lungs. — The  change  in  the  condition  of  the  blood,  in  regard  to  the  relative  pro- 
portions of  its  oxygen  and  carbonic  acid,  is  the  only  one  to  which  the  Pulmonary 
circulation  is  subservient;  but  in  the  Systemic  circulation,  the  changes  are  of  a 
much  more  complex  nature,  every  distinct  organ-  attracting  to  itself  the  peculiar 
substances  which  it  requires  as  the  materials  of  its  own  nutrition,  and  the  nature 
of  the  affinities  thus  generated  being  consequently  different  in  each  case.  But 
the  same  law  may  be  considered  to  hold  good  in  all  instances.  Thus  the  blood 
conveyed  to  the  Liver  by  the  portal  vein,  contains  the  materials  at  the  expense 
of  which  the  bile-secreting  cells  are  developed;  consequently  the  tissue  of  the 
liver,  which  is  principally  made  up  of  these  cells,  possesses  a  certain  degree  of 
affinity  or  attraction  for  blood  containing  these  materials ;  and  this  is  diminished, 
so  soon  as  they  have  been  drawn  from  it  into  the  cells  around.  Consequently 
the  blood  of  the  portal  vein  will  drive  before  it,  into  the  hepatic  vein,  the  blood 
which  has  traversed  the  capillaries  of  the  portal  system,  and  which,  in  doing  so, 
has  given-up  the  elements  of  bile  to  the  solid  tissues  of  the  liver. 

stimulus  of  venous  blood  ("Edinb.  Med.  and  Surg.  Journ.,"  Jan.  1845);  for  all  experi- 
ments agree  in  showing,  that  such  contraction  can  only  be  excited  by  the  application  of  a 
stimulus  for  some  minutes,  and  that  relaxation  takes  place  still  more  slowly  ($  256). 
1  "  Treatise  on  the  Forces  which  produce  the  Organization  of  Plants,"  pp.  22 — 41. 


MOVEMENT    OF    THE    BLOOD    IN    THE    VEINS.  275 

276.  The  influence  which  the  Nervous  System  is  known  to  exert  upon  the 
functions  of  Nutrition  and   Secretion    (§§  33,  37),  which   are  very  intimately 
related  to  the  movement  of  the  blood  in  the  Capillaries,  would  lead  us  to  expect 
that  it  should  exercise  some  like  influence  over  that  movement  itself.     And  two 
distinct  channels  for  such  an  influence  may  be  assigned  with  much  probability; 
first,  the  control  exercised  by  the  Sympathetic  system  over  the  diameter  of  the 
smaher  arteries  (§  256),  which  will  thus  regulate  the  rate  at  which  the  blood  is 
supplied  to  the  capillary  plexus ;  and  second,  the  direct  agency  of  Nerve-force  in 
stimulating,  retarding,  or  modifying  those    molecular  changes,   in   which    the 
Nutritive  and  Secretory  operations  consist.  (See  PRINC.  or  GEN.  PHYS.,  Am.  Ed.) 
— That  the  ordinary  action  of  this  force  is  not  required  to  sustain  the  Capillary 
circulation,  is  clearly  proved  by  the  continuance  of  the  flow  without  any  appa- 
rent alteration,  after  section  of  the  nerves  of  the  part,  as  has  been  observed  by 
Miiller,  Wharton  Jones,  and  others ;  and  this  corresponds  with  the  well-known 
fact,  that  the  Nutritive  and  Secretory  processes  may  take  place,  after  Nervous 
agency  has  been  thus  suspended.     But  it  seems  indubitable  that  a  sudden  and 
violent  ( shock '  to  the  Nervous  centres  may  exert  the  same  antagonistic  influence 
on  the  movement  of  blood  in  the  Capillaries,  as  we  have  seen  it  to  do  on  the 
Heart's  action  (§  238)  :  for  this  appears  alike  from  the  immediate  and  total  an- 
nihilation of  all  vital  activity  which  is  consequent  upon  such  an  injury,  and  from 
direct  observation  in  such  an  experiment  as  the  following,  made  by  Dr.  Wilson 
Philip.     "  The  web  of  one  of  the  hind  legs  of  a  frog  was  brought  before  the 
microscope;  and  while  Dr.  Hastings  observed  the  circulation,  which  was  vigorous, 
the  brain  was  crushed  by  the  blow  of  a  hammer.     The  vessels  of  the  web  in- 
stantly lost  their  power,  the  circulation  ceasing;  an  effect  which  cannot  arise,  as 
we  have  seen,  from  the  ceasing  of  the  action  of  the  heart.     [Dr.  P.  here  refers 
to  experiments,  by  which  it  was  ascertained,  that  the  circulation  in  the  capillary- 
vessels  of  the  frog  will  continue  for  several  minutes,  after  the  interruption  of  the 
heart's  action.]     In  a  short  time  the  blood  again  began  to  move,  but  with  less 
force.     This  experiment  was  repeated  with  the  same  result.     If  the  brain  is  not 
completely  crushed,  although  the  animal  is  killed,  the  blow,  instead  of  destroy- 
ing the  circulation,  increases  its  rapidity."1 

5. — Movement  of  the  Blood  in  the  Veins. 

277.  The  Venous  system  takes  its  origin  in  the  small  trunks  that  are  formed 
by  the  re-union  of  the  Capillaries ;  and  it  returns  the  blood  from  these  to  the 
Heart.     The  structure  of  the  Veins  is  essentially  the  same  with  that  of  the 
Arteries ;  but  the  fibrous  tissue  of  which  their  middle  coat  is  made-up,  bears 
more  resemblance  to  the  areolar  tissue  of  the  skin,  than  it  does  to  the  true  elastic 
tissue;  and  the  muscular  fibre-cells  are  usually  much  fewer  in  number,  and  are 
sometimes  wanting  altogether.2     The  elasticity  of  the  Veins  is  shown  by  the  jet 
of  blood  which  at  first  spouts-out  in  ordinary  venesection,  when,  by  means  of  the 
ligature,  a  distension  has  been  occasioned  in  the  tubes  below  it.     A  slight  con- 
tractility on  the  application  of  stimuli,  and  on  irritation  of  the  Sympathetic  ner- 
vous fibres,  has  been  observed ;  but  this  is  not  so  decided  as  in  the  arteries.     The 
whole  capacity  of  the  Venous  system  is  considerably  greater  than  that  of  the 
arterial ;  the  former  is  usually  estimated  to  contain  from  2  to  3  times  as  much 
blood  as  the  latter,  in  the  ordinary  condition  of  the  circulation ;  and  when  we 
consider  the  great  proportion,  which  the  Veins  in  almost  every  part  of  the  body 
bear  to  the  arteries,  we  shall  scarcely  regard  even  the  larger  of  these  ratios  as 

1  "Experimental  Inquiry  into  the  Laws  of  the  Vital  Functions,"  4th  edition,  p.  52. 

B  The  following,  according  to  Prof.  Kolliker  ("  Manual  of  Human  Histology,"  Syd.  Scc.; 
vol.  ii.  p.  307),  are  Veins  which  are  unprovided  with  muscular  structure: — The  veins  of 
the  uterine  portion  of  the  placenta;  the  veins  of  the  cerebral  substance  and  pia  mater; 
the  sinuses  of  the  dura  mater;  Breschet's  veins  of  the  bones;  the  venous  cells  of  the 
corpora  cavernosa  in  the  male  and  female ;  and  probably  the  venous  cells  of  the  spleen. 


276       OF  THE  CIRCULATION  OF  THE  BLOOD. 

exaggerated.  Of  course  the  rapidity  of  the  movement  of  the  blood  in  the  two 
systems,  will  bear  an  inverse  ratio  to  their  respective  capacities ;  thus  if,  in  a 
given  length,  the  veins  contain  three  times  as  much  blood  as  the  arteries,  the 
fluid  will  move  with  only  one-third  of  the  velocity.  Even  at  their  origins  in  the 
capillary  plexus,  the  veins  are  larger  than  the  arteries  which  terminate  in  the 
same  plexus;  so  that  wherever  the  arterial  and  venous  networks  form  distinct 
strata,  they  are  readily  distinguished  from  each  other.  The  Veins  are  remark- 
able for  the  number  of  valves  which  they  contain,  formed  of  duplicatures  or 
loose  folds  of  the  internal  tunic,  between  the  component  laminae  of  which,  con- 
tractile fibres  are  interposed ;  and  also  for  the  dilatations  behind  these,  which, 
when  distended,  give  them  a  varicose  appearance.  The  valves  are  single  in  the 
small  veins,  the  free  edge  of  the  flap  closing  against  the  opposite  wall  of  the 
vein ;  in  the  larger  trunks  they  are*  double ;  and  in  a  few  instances  they  are 
composed  of  three  flaps.  The  object  of  these  valves  is  evidently  to  prevent  the 
reflux  of  blood ;  and  we  shall  presently  see,  that  they  are  of  important  use  in 
assisting  in  the  maintenance  of  the  venous  circulation.  They  are  most  numerous 
in  those  veins,  which  run  among  parts  affected  by  muscular  movement;  and  they 
are  not  found  in  the  veins  of  the  lungs,  of  the  abdominal  viscera,  or  of  the 
brain. 

278.  The  movement  of  the  blood  through  the  Veins  is,  without  doubt,  chiefly 
effected  by  the  vis  a  tergo  or  propulsive  force,  which  results  from  the  action  of 
the  heart  and  arteries;  this,  as  already  shown  (§  263),  is  very  greatly  dimi- 
nished by  the  time  that  it  acts  on  the  blood  in  the  veins ;  but  the  resistance  to 
the  onward  movement  of  the  blood  is  now  so  slight,  that  a  very  feeble  power  is 
adequate  to  overcome  it.  There  are  some  concurrent  causes,  however,  which  are 
supposed  by  some  to  have  much  influence  upon  it,  and  of  which  the  consideration 
must  not  be  neglected.  —  One  of  these,  is  the  suction-power  attributed  to  the 
Heart;  acting  as  a  vis  afronte,  in  drawing  the  blood  towards  it.  It  is  doubtful 
how  far  the  Auricles  have  such  a  power  of  active  dilatation,  as  that  which  would 
be  required  for  this  purpose ;  and  no  sufficient  evidence  has  been  given,  that  the 
current  of  blood  at  any  distance  from  the  Heart  is  affected  by  it.  Indeed,  for  a 
reason  to  be  presently  stated,  this  may  be  regarded  as  impossible. — Another  im- 
portant agency  has  been  found  by  some  Physiologists,  in  the  inspiratory  move- 
ment; this  is  supposed  to  draw  the  blood  of  the  Veins  into  the  chest,  in  order 
to  supply  the  vacuum  which  is  created  there  at  the  moment  of  the  descent  of 
the  diaphragm.  That  the  movement  in  question  has  some  influence  on  the  flow 
of  venous  blood  into  the  chest,  is  evident  from  the  occurrence  of  the  respiratory 
pulse,  long  ago  described  by  Haller;  which  may  be  seen  in  the  veins  of  the 
neck  and  shoulder  in  thin  persons,  and  in  those  especially  who  are  suffering  from 
pulmonary  diseases.  During  Inspiration,  the  Veins  are  seen  to  be  partially 
emptied  :  whilst  during  Expiration  they  become  turgid,  partly  in  consequence 
of  the  accumulation  from  behind,  and  of  the  check  in  front ;  and  partly  (it  may 
be)  in  some  cases,  through  an  absolute  reflux  from  the  veins  within  the  chest 
(§  247).  The  fact  that  in  the  immediate  neighbourhood  of  the  chest,  the  flow 
of  blood  towards  the  heart  is  aided  by  inspiration  and  impeded  by  expiration,  is 
further  proved  by  Sir  D.  Barry's  experiment,  which  consisted  in  introducing  one 
extremity  of  a  tube  into  the  jugular  vein  of  a  Horse,  and  the  other  into  water, 
which  exhibited  an  alternate  elevation  and  depression  with  inspiration  and  expi- 
ration; this  has  been  repeated  and  confirmed  by  several  Physiologists.  On  the 
other  hand,  the  expiratory  movement,  while  it  directly  causes  accumulation  in 
the  veins,  will  assist  the  heart  in  propelling  the  blood  into  the  arteries;  and  by 
the  combined  action  of  these  two  causes  is  produced  among  other  effects,  the 
rising  and  sinking  of  the  Brain  synchronously  with  expiration  and  inspiration, 
which  are  observed  when  a  portion  of  the  cranium  is  removed.  Several  consi- 
derations, however,  agree  in  pointing  to  the  conclusion,  that  no  great  efficacy 
ian  be  rightly  attributed  to  the  Respiratory  movements,  as  exerting  any  general 


MOVEMENT  OF  THE  BLOOD  *N  THE  VEINS.     277 

influence  over  the  Venous  circulation.  The  Pulmonary  circulation,  being 
entirely  within  the  chest,  cannot  be  affected  by  variations  in  atmospheric  pres- 
sure ;  the  entire  venous  circulation  of  the  foetus,  also,  is  independent  of  any 
such  agency.  Again,  it  has  been  shown  experimentally  by  Dr.  Arnott  and 
others,  that  no  suction-power  exerted  at  the  farther  end  of  a  long  tube,  whose 
walls  are  so  deficient  in  firmness  as  are  those  of  the  Veins,  can  occasion  any  acce- 
leration in  a  current  of  fluid  transmitted  through  it;  for  the  effect  of  the  suction 
is  destroyed,  at  no  great  distance  from  the  point  at  which  it  is  applied,  by  the 
flapping  together  of  the  sides  of  the  vessel. 

279.  One  of  the  most  powerful  of  the  general  causes  which  influence  the 
Venous  circulation,  is  doubtless  the  frequently-recurring  pressure  of  the  muscles 
upon  their  trunks.     In  every  instance  that  Muscular  movement  takes  place,  a 
portion  of  the  Veins  of  the  part  will  undergo  compression ;  and  as  the  blood  is 
prevented,  by  the  valves  in  the  veins,  from  being  driven-back  into  the  small 
vessels,  it  is  necessarily  forced-on  towards  the  heart.     As  each  set  of  muscles  is 
relaxed,  the  veins  compressed  by  it  fill-out  again,  to  be  again  compressed  by  the 
renewal  of  the  force.     That  the  general  Muscular  movement  is  an  important 
agent  in  maintaining  the  circulation,  at  a  point  above  that  at  which  it  would  be 
kept  by  the  action  of  the  heart  and  arterial  system  alone,  appears  from  several 
considerations.     The  pulsations  are  diminished  in  frequency  by  rest,  accelerated 
by  exertion,  and  very  much  quickened  by  violent  effort  (§  254  d).     In  all  kinds 
of  exercise,  and  in  almost  every  sort  of  effort,  there  is  that  alternate  contraction 
and  relaxation  of  particular  groups  of  Muscles,  which  has  been  just  mentioned 
as  affecting  the  flow  of  blood  through  the  veins ;  and  there  can  be  little  doubt, 
that  the  increased  rapidity  of  the  return  of  blood  through  them,  is  of  itself  suf- 
ficient cause  for  the  accelerated  movements  of  the  heart.     When  a  large  number 
of  muscles  are  put  in  action  after  repose,  as  is  the  case  when  we  rise-up  from  a 
recumbent  or  a  sitting  posture,  the  blood  is  driven  to  the  heart  with  a  very  strong 
impetus ;  and  if  that  organ  should  be  diseased,  it  may  arrive  there  in  a  quantity 
larger  than  can  be  disposed-of ;  so  that  sudden  death  may  be  the  result.     Hence 
the  necessity  for  the  avoidance  of  all  sudden  and  violent  movements,  on  the  part 
of  those  who  labour  under  either  a  functional  or  a  structural  disease  of  the  centre 
of  the  circulation. 

280.  The  Venous  circulation  is  much  more  liable  than  the  Arterial,  to  be  in- 
fluenced by  the  force  of  Gravity;  and  this  influence  is  particularly  noticeable, 
when  the  tonicity  of  the  vessels  is  deficient.  —  The  following  experiments  per- 
formed by  Dr.  C.  J.  B.  Williams,1  to  elucidate  the  influence  of  deficient  firmness 
in  the  walls  of  the   vessels,  and  of  gravitation,  over  the  movement  of  fluids 
through  tubes,  throw  great  light  on  the  causes  of  venous  congestion.     A  tube 
with  two  equal  arms  having  been  fitted  to  a  syringe,  a  brass  tube  two  feet  long, 
having  several  right  angles  in  its  course,  was  adapted  to  one  of  them,  whilst  to 
the  other  was  tied  a  portion  of  a  rabbit's  intestine  four  feet  long,  and  of  calibre 
double  that  of  the  brass  tube,  this  being  arranged  in  curves  and  coils,  but  with- 
out angles  or  crossings.     When  the  two  tubes  were  raised  to  the  same  height, 
the  small  metal  tube  discharged  from  two  to  five  times  the  quantity  of  water 
discharged  in  a  given  time  by  the  larger  but  membranous  tube;  the  difference 
being  greatest,  when  the  strokes  of  the  piston  were  most  forcible  and  sudden,  by 
which  the  intestine  was  much  dilated  at  its  syringe-end,  but  conveyed  very  little 
more  water.     When  the  discharging  ends  were  raised  a  few  inches  higher,  the 
difference  increased  considerably,   the  amount  of  fluid  discharged  by   the  gut 
being  much  diminished ;  and  when  the  ends  were  raised  to  the  height  of  eight 
or  ten  inches,  the  gut  ceased  to  discharge,  each  stroke  only  moving  the  column 
of  water  in  it,  and  this  subsiding  again,  without  rising  high  enough  to  overflow. 
When  the  force  of  the  stroke  increased,  the  part  of  the  intestine  nearest  the 
syringe  burst.  —  From  these  experiments  it  is  easy  to  understand,  how  any  de- 

1  "Principles  of  Medicine,"  3d  Am.  Edit.,  p.  156. 


L'78        OF  THE  CIRCULATION  OF  THE  BLOOD. 

ficiency  of  '  tone '  in  the  Venous  system  will  tend  to  prevent  the  ascent  of  the 
blood  from  the  depending  parts  of  the  body,  and  will  consequently  occasion  an 
increased  pressure  on  the  walls  of  the  vessels,  and  an  augmentation  in  the  quan- 
tity of  blood  they  contain.  All  these  conditions  are  peculiarly  favourable  to  the 
escape  of  the  watery  part  of  the  blood  from  the  small  vessels ;  and  this  may 
either  infiltrate  into  the  areolar  tissue,  or  it  may  be  poured  into  some  neighbour- 
ing serous  cavity,  producing  dropsy.  Thus  it  happens,  that  such  effusions  may 
often  be  traced  to  that  state  of  deficient  vigour  of  the  system,  which  particularly 
manifests  itself  in  want  of  tone  of  the  blood-vessels ;  and  that  it  is  relieved  by 
remedies  which  restore  this.  In  many  young  females  of  leuco-phlegmatic  tem- 
perament, for  example,  there  is  a  tendency  to  swelling  of  the  feet,  by  cedematous 
effusion  into  the  areolar  tissue,  in  consequence  of  the  depending  position  of  tho 
limbs ;  the  oedema  disappears  during  the  night,  but  returns  during  the  day,  and 
is  at  its  maximum  in  the  evening.  And  the  congestion  which  frequently  mani- 
fests itself  in  the  posterior  parts  of  the  body,  towards  the  close  of  exhausting 
diseases  in  which  the  patient  has  lain  much  upon  his  back,  is  attributable  to  a 
similar  cause ;  of  such  congestion,  effusions  into  the  various  serous  cavities  are 
frequent  results;  and  such  effusions,  taking  place  during  the  last  hours  of  life, 
are  often  erroneously  regarded  as  the  source  of  death.  To  the  same  cause  we 
are  to  attribute  the  varicose  state  of  the  veins  of  the  leg,  which  is  so  common 
amongst  persons  of  relaxed  fibre,  and  especially  in  those  whose  habits  require 
them  to  be  much  in  the  erect  posture ;  arid  this  distension  occasionally  proceeds 
to  complete  rupture,  the  causes  of  which  are  fully  elucidated  by  the  experiments 
just  cited. 

6. — Peculiarities  of  the  Circulation  in  different  Parts. 

281.  In  several  portions  of  the  Human  body,  there  are  certain  varieties  in  the 
distribution  and  in  the  functional  action  of  the  blood-vessels,  which  should  not 
be  omitted  in  a  general  account  of  the  Circulation.  —  Of  these,  we  have  in  the 
first  place  to  notice  the  apparatus  for  the  Pulmonary  circulation  ;  the  chief  pecu- 
liarity of  which  is,  that  venous  blood  is  sent  from  the  heart,  through  a  tube 
which  is  arterial  in  its  structure,  whilst  arterial  blood  is  returned  to  the  heart, 
through  a  vessel  whose  entire  character  is  that  of  a  vein.  The  movement  of  the 
blood  through  these  is  considerably  affected  by  the  physical  state  of  the  lungs 
themselves;  being  retarded  by  any  causes,  which  can  occasion  pressure  on  the 
vessels  (such  as  over-distension  of  the  cells  with  air,  obstruction  of  their  cavity 
by  solid  or  fluid  depositions,  or  by  foreign  substances  injected  into  them,  &c.) ; 
and  proceeding  with  the  greatest  energy  and  regularity,  when  the  respiratory 
movements  are  freely  performed.  —  The  Portal  circulation,  again,  is  peculiar,  in 
being  a  kind  of  offset  from  the  general  or  systemic  circulation,  and  also  in  being 
destitute  of  valves ;  and  it  may  be  surmised  with  much  probability,  that  the  pur- 
pose of  their  absence  is,  to  allow  of  an  unusually  free  passage  of  blood  from  one 
part  of  that  system  to  another,  during  the  very  varying  conditions  to  which  it  is 
subjected  (§  151).  —  Another  very  important  modification  of  the  Circulating 
system,  is  that  which  presents  itself  within  the  Cranium.  From  the  circum- 
stance of  the  cranium  being  a  closed  cavity,  which  must  be  always  filled  with  the 
game  total  amount  of  contents,  the  flow  of  blood  through  its  vessels  is  attended 
with  some  peculiarities.  The  pressure  of  the  atmosphere  is  here  exerted,  rather 
to  keep  the  blood  in  the  head,  than  to  force  it  out;  and  it  might  accordingly  be 
inferred,  that,  whilst  the  quantity  of  cerebral  matter  remains  the  same,  the 
amount  of  blood  in  the  cranial  vessels  must  also  be  invariable.  This  inference 
appeared  to  derive  support  from  the  experiments  of  Dr.  Kellie.1  On  bleeding 
animals  to  death,  he  found  that,  whilst  the  remainder  of  the  body  was  completely 
exsanguine,  the  usual  quantity  of  blood  remained  in  the  arteries  and  veins  of 
the  cranium ;  but  that  if  an  opening  was  made  in  the  skull,  these  vessels  were 

"  Edinburgh  Medico-Chirurgical  Transactions,"  vol.  i. 


PECULIARITIES    OF   THE    CIRCULATION.  —  ERECTILE    TISSUES.        279 

then  as  completely  emptied  as  the  rest.  It  is  not  to  be  hence  inferred,  however, 
that  the  absolute  quantity  of  blood  within  the  cranium  is  not  subject  to  varia- 
tion ;  and  that  in  the  states  of  inflammation,  congestion,  or  other  morbid  affec- 
tions, there  is  only  a  disturbance  of  the  usual  balance  of  the  arterial  and  venous 
circulation.  The  fact  in  all  probability  is  rather,  that  the  softness  of  the  Cere- 
bral tissue,  and  its  varying  functional  activity,  render  it  peculiarly  liable  to 
undergo  alterations  in  bulk;  and  that  the  amount  of  the  '  cerebro-spinal  fluid' 
varies  considerably  at  different  times ;  so  that  the  quantity  of  blood  may  thus, 
even  in  the  healthy  condition,  be  continually  changing.  Moreover,  in  disordered 
states  of  the  circulation,  the  quantity  of  blood  in  the  vessels  of  the  cranium  may 
be  for  a  time  diminished  by  a  sudden  extravasation,  either  of  blood  or  serum, 
into  the  cerebral  substance;  and  the  amount  of  interior  pressure  upon  the  walls 
of  the  vessels  may  also  be  considerably  altered,  even  when  there  is  no  difference 
in  the  quantity  of  fluid  contained  in  them.1 

282.  The  Erectile  Tissues  present  another  curious  modification  of  the  ordinary 
vascular  apparatus.  The  chief  of  these  are  the  corpora  cavernosa  in  the  penis 
of  the  male,  and  in  the  clitoris  of  the  female;  the  collection  of  similar  tissues 
round  the  vagina,  and  in  the  nymphae,  of  the  female;  and  the  nipple  in  both 
sexes.  In  all  these  situations,  erection  may  be  produced  by  local  irritation;  or 
it  may  take  place  as  a  result  of  certain  emotional  conditions  of  the  mind,  the 
influence  of  which  is  probably  transmitted  through  the  Sympathetic  nerve,  as  it 
may  be  experienced  even  in  cases  of  paraplegia.  The  erectile  tissue  appears 
essentially  to  consist  of  a  plexus  of  veins  with  varicose  enlargements,  inclosed  in 
a  fibrous  envelope  with  trabecular  partitions.  This  envelope,  according  to  the 
recent  researches  of  Prof.  Kolliker,2  contains  a  large  amount  of  non-striated  mus- 
cular fibre ;  the  contraction  of  which  is  doubtless  in  some  way  concerned  in  the 
result.  In  the  penis,  as  first  pointed-out  by  Prof.  Miiller,3  there  are  two  sets  of 
arteries;  those  of  one  set,  destined  for  the  nutrition  of  the  tissues,  communica- 
ting with  the  veins  in  the  usual  way,  through  a  capillary  network ;  whilst  the 
others,  termed  by  him  the  'helicine  arteries,'  are  short  tendril-like  branches, 
which  project  into  the  veins  (covered,  however,  by  their  lining  membrane),  some- 
times singly,  and  sometimes  in  tufts,  ending  abruptly  by  dilated  extremities.  It 
was  maintained  by  Miiller,  that  the  dilated  ends  of  these  helicine  arteries  com- 
municate directly  with  the  venous  cavities,  since  injection  thrown  into  the  former 
always  fills  the  latter,  although  no  distinct  apertures  have  been  seen  in  them ; 
and  Kolliker  states  that  he  has  frequently  found  them  giving-off  delicate,  almost 
capillary  vessels,  which  discharge  themselves  into  the  venous  spaces. — The  proxi- 
mate cause  of  the  erection  of  the  penis,  has  been  stated  by  some  to  be  the  action 
of  the  ischio-cavernosi  and  the  bulbo-cavernosus  muscles,  in  compressing  the 
veins  which  return  the  blood  from  the  penis ;  but  although  these  muscles  pro- 
bably afford  assistance  in  completing  and  strengthening  the  erection,  they  are 
unablo  to  effect  it  by  their  own  act;  and  it  is  obvious  that  no  analogous  power 
can  be  exerted  in  other  erectile  organs,  the  nipple  for  example — It  is  maintained 
by  Prof.  Kolliker,  that  the  office  of  the  muscular  fibres  which  pass  in  every 
direction  amongst  the  dilated  veins,  is  to  keep  them  compressed  in  the  intervals 
of  erection,  so  as  to  prevent  them  from  being  distended  by  the  vis  a  teryo  of  the 
blood;  and  that  the  stimulus  to  erection,  which  is  usually  conveyed  through  the 
nervous  system,  so  operates  upon  these  fibres  as  to  occasion  their  relaxation, 
whereby  the  free  distension  of  the  cavernous  veins  and  of  the  arterial  diverticula 

1  The  results  of  the  more  recent  experiments  of  Dr.  G.  Burrows  ("Medical  Gazette," 
April  and  May,  1843)  fully  confirm  the  views  stated  above. 

2  See  his  essay  "  Das  Anatomische  und  Physiologische  Verhalten  der  Cavernoser  Korpes 
der  Sexual  organe,"  1851 ;  and  his  "Manual  of  Human  Histol^y"  (Sydenham  Society), 
vol.  ii.  pp.  237—244. 

3  'Entdeckung  der  bei  der  Erection  wirksamen  Arterien,'  IB.   'Muller's  Archiv.,'f  1835 
p.  202. 


280  OF    RESPIRATION. 

is  permitted.  He  refers,  moreover,  to  the  excessive  contraction  of  erectile 
organs  which  is  induced  by  cold,1  and  to  the  effect  of  warmth  in  favouring  their 
enlargement,  as  confirmatory  of  this  view;  and  considers  that  no  other  agency  is 
required.  Now  although  we  are  so  accustomed  to  consider  the  stimulus  of  in- 
nervation  as  exerted  in  producing  muscular  contraction,  yet  since,  in  the  act  of 
Blushing,  there  is  undoubtedly  a  relaxation  of  the  muscular  walls  of  the  blood- 
vessels under  the  influence  of  emotional  excitement,  there  seems  a  strong  ana- 
logical probability  (at  any  rate,  no  d  priori  improbability)  that  the  same  may  be 
the  case  with  the  act  of  Erection. 


CHAPTER  VII. 

0  F     RESPIRATION. 

1. — Nature  of  the  Function:  and  Provisions  for  its  Performance. 

283.  THE   Nirritive  fluid,  in  its  circulation  through  the   capillaries   of  the 
system,  undergoes  great  alterations  both  in  its  physical  constitution,  and  in  its 
vital  properties.     It  gives-up  to  the  tissues  with  which  it  is  brought  into  contact, 
some  of  its  most  important  elements;  and,  at  the  same   time,  it  is  made  the 
vehicle  of  removal,  from  these  tissues,  of  ingredients  which  are  no  longer  in  the 
state  of  combination  that  fits  them  for  their  offices  in  the  Animal  Economy.     To 
separate  these  ingredients  from  the  general  current  of  the  circulation,  and  to 
carry  them  out  of  the  system,  is  the  great  object  of  the  Excretory  organs;  the 
importance  of  whose  respective  functions  will  vary,  it  is  very  evident,  with  the 
amount  of  the  ingredient  which  they  have  to  separate,  and  with  the  deleterious 
influence  which  its  retention  would  exert  on  the  welfare  of  the  system  at  large. 
Of  all  these  injurious  ingredients,  Carbonic  Acid  is  without  doubt  the  one  most 
abundantly  introduced  into  the  nutritive  fluid ;  and  it  is  also  most  deleterious  in 
its  effects  on  the  system,  if  allowed  to  accumulate. — We  find,  accordingly,  that 
the  provision  for  the  removal  of  this  substance  from  the  blood,  is  one  of  peculiar 
extent  and  importance,  especially  in  the  higher  forms  of  animals ;  and  further, 
that  instead  of  being  effected  by  an  operation  peculiarly  vital  (like  other  acts  of 
Excretion),  its  performance  is  secured  by  being  made  to  depend  upon  simple 
physical  conditions,  and  is  thus  comparatively  little  susceptible  of  derangement 
from  disorder  of  other  processes.     All  that  is  requisite  for  it,  is  the  exposure  of 
the  Blood  to  the  influence  of  the  Atmospheric  air  (or,  in  aquatic  animals,  of  air 
dissolved  in  water),  through  the  medium  of  a  membrane  that  shall  permit  the 
'  diffusion  of  gases;'  an  interchange  then  taking  place  between  the  gaseous  mat- 
ters on  the  two  sides,  —  Carbonic  acid  being  exhaled  from  the  Blood,  and  being 
replaced  by  Oxygen  from  the  air.     Thus  the  extrication  of  Carbonic   acid  is 
effected  in  a  manner  that  renders  it  subservient  to  the  introduction  of  that  ele- 
ment which  is  required  for  all  the  most  active  manifestations  of  vital  power; 
and  it  is  in  these  two  processes  conjointly,  not  in  either  alone,  that  the  function 
of  Respiration  essentially  consists.  — We  shall  now  inquire  into  the  sources  from 
which  Carbonic  acid  is  produced  in  the  living  body,  and  the  causes  of  the  demand 
fur  Oxygen. 

284.  The  vital  activity  of  the  organism  at  large  involves  a  continual  change 
in  its  constituent  parts;  and  those  which  (so  to  speak)  live  the  fastest,  usually 
die  the  soonest,  and  pass  most  readily  into  decay  (CHAP,  vni.,  Sect.  1).     Hence 
in  the  very  performance  of  the  Organic  functions  which  concur  to  effect  the  Nu- 
trition of  the  body,  there  is  a  constant  source  of  disintegration ;  and  one  of  the 

1  The  application  of  moderate  cold,  however,  (as  in  putting-on  a  clean  shirt)  frequently 
occasions  erection  of  the  male  nipple. 


GENERAL    STRUCTURE    OF   THE   RESPIRATORY   ORGANS.  281 

chief  products  of  the  decay  of  the  tissues,  which  is  consequent  upon  their  loss 
of  vitality,  is  Carbonic  acid.  —  Thus  the  most  general  object  of  the  Respiratory 
process,  which  is  common  to  all  forms  of  organized  being,  is  the  extrication  of 
this  product  from  the  system;  and  the  demand  for  aeration  hence  arising,  will 
vary  with  the  activity  of  the  nutritive  operations.  Now  the  rate  of  life,  and 
consequently  the  amount  of  disintegration,  in  any  organized  structure,  depend  in 
great  measure  upon  the  temperature  at  which  it  is  maintained  (See  PRINC.  OF 
(TEN.  PHYS.)  ;  and  thus  it  happens  that  the  production  of  Carbonic  acid  from 
this  source,  at  the  ordinary  rate  of  vital  activity,  is  much  more  rapid  in  (  warm- 
blooded'  than  in  cold-blooded'  animals,  and  that  the  former  suffer  far  more 
speedily  than  the  latter  from  the  privation  of  air.  But  when  the  temperature 
of  the  Reptile  is  raised  by  external  heat  to  the  level  of  that  of  the  Mammal,  its 
need  for  respiration  increases,  owing  to  the  augmented  waste  of  its  tissues. 
When,  on  the  other  hand,  the  warm-blooded  Mammal  is  reduced,  in  the  state  of 
hybernation,  to  the  level  of  the  cold-blooded  Reptile,  the  waste  of  its  tissues 
diminishes  to  such  an  extent,  as  to  require  but  a  very  small  exertion  of  the  respi- 
ratory process  to  get-rid  of  the  carbonic  acid,  which  is  one  of  its  chief  products. 
And  in  those  animals  which  are  capable  of  retaining  their  vitality  when  they  are 
frozen,  or  when  their  tissues  are  completely  dried-up,  vital  activity  and  disinte- 
gration are  alike  entirely  suspended,  and  consequently  there  is  no  carbonic  acid 
to  be  set-free. 

285.  But  another  source  of  Carbonic  acid  to  be  set-free  by  the  Respiratory  pro- 
cess, and  one  which  is  peculiar  to  animals,  consists  in  the  rapid  changes  which  take 
place  in  the  Muscular  and  Nervous  tissues,  in  the  very  act  of  performing  their 
peculiar  functions  ;  the  development  of  the   Muscular  and  Nervous  forces  in- 
volving, as  the  very  condition  of  their  production,  a  change  in  the  substance  of 
these  tissues  respectively ;  in  which  change  a  large  quantity  of  Oxygen  is  con- 
sumed,  and  a  large  amount  of  Carbonic  acid  is  generated.     Hence  in  Man,  as  in 
all  Animals  in  which  the  Nervo-Muscular  apparatus  constitues  the  essential  part 
of  the  organism,  a  powerful  demand  for  Respiration  is  created  by  its  activity ; 
the  amount  of  oxygen  taken-in,  and  of  carbonic  acid  exhaled,  being  determined, 
cceteris  pnribus,  by  the  degree  in  which  this  apparatus  is  exercised.  —  That  Car- 
bonic acid  is  set-free  ready-formed  by  the  muscles,  and  is  not  generated  by  the 
oxidation  of  the  products  of  their  disintegration  after  the  reception  of  these  into 
the  blood-current,  has  been  shown  by  the  experiments  of  Dr.  Gr.  Liebig;1  who 
found  that  carefully-prepared  frogs'  muscles  absorb  oxygen  and  exhale  carbonic 
acid  so  long  as  their  contractility  lasts,  even  when  they  have  been   completely 
deprived  of  blood.     So  that,  in  this  instance,  as  probably  in  all  others  of  its  kind, 
the  first  interchange  of  gases  takes  place  in  the  parenchyma  of  the  organs  them- 
selves,—  oxjgen  being  drawn  by  them  from  the  blood,  and  carbonic  acid  being 
imparted  to  it;  and  the  converse  change  must  be  as  constantly  effected  in  the 
lungs,  in  order  that  the  circulating  medium  may  be  maintained  in  the  requisite 
state  of  purity. 

286.  Besides  these  sources  of  Carbonic  acid  which  are  common  to  all  Animals, 
there  is  another  which  is  restricted  (or  nearly  so)  to  the   two  highest  classes, 
Birds  and  Mammals ;  these  being  distinguished  by  their  power  of  maintaining  a 
constantly-elevated  temperature.      A  part  of  this  Heat  is  generated  by  the  oxy- 
genation  of  the  components  of  their  disintegrating  tissues,  the  metamorphosis 
of  which  takes  place  at  a  very  rapid  rate;  but  where  this  is  not  sufficient,  their 
power  of  maintaining  their  temperature  depends  upon  the  direct  combination  of 
certain  elements  of  the  food  with  the  oxygen  of  the  air,  by  the  combustive  pro 
cess. — The  quantity  of  carbonic  acid  that  is  generated  directly  from  the  elements 
of  the  food,  seems  to  vary  considerably  in  different  animals,  and  in  different 
states   of  the   same   individual.     In   the   Carnivorous   tribes,  which    spend   the 
greater  part  of  their  time  in  a  state  of  activity,  it  is  probable  that  the  quantity 

1  "  Bericht.  d.  Akad.  d.  Wissensch.  zu  Berlin,"  1850,  $$  339—347. 


282  OF    RESPIRATION. 

which  is  generated  by  the  waste  or  metamorphosis  of  the  tissues  is  sufficient  for 
the  maintenance  of  the  required  temperature  ;  and  that  little  or  none  of  the  car- 
bonic acid  set-free  in  respiration,  is  derived  from  the  direct  combustion  of  the 
materials  of  the  food.  But  in  Herbivorous  animals  of  comparatively  inert 
habits,  the  amount  of  metamorphosis  of  the  tissues  is  far  from  being  sufficient; 
and  a  large  part  of  the  food,  consisting  as  it  does  of  substances  that  cannot  be 
applied  to  the  nutrition  of  the  tissues,  is  made  to  enter  into  direct* combination 
with  the  oxygen  of  the  air,  and  thus  to  compensate  for  the  deficiency.  In  Man 
and  other  animals,  which  can  sustain  considerable  variations  of  climate,  and  can 
adapt  themselves  to  a  great  diversity  of  habits,  the  quantity  of  carbonic  acid 
formed  by  the  direct  combination  of  the  elements  of  the  food  with  the  oxygen 
of  the  air,  will  differ  extremely  under  different  circumstances  (§  55).  It  will 
serve  as  the  complement  of  that  which  is  formed  in  other  ways ;  so  that  it  will 
diminish  with  the  increase,  and  will  increase  with  the  diminution,  of  muscular 
activity.  It  will  also  vary  in  an  inverse  ratio  to  the  external  temperature,  in- 
creasing with  its  diminution  (as  more  heat  must  then  be  generated),  and  dimi- 
nishing with  its  increase ;  the  effect  of  external  heat  being  thus  precisely  oppo- 
site, in  the  warm-blooded  animal,  to  that  which  it  exerts  on  the  cold-blooded 
(§  284). — In  all  cases,  if  a  sufficient  supply  of  food  be  not  furnished,  the  store 
of  fat  is  drawn-upon ;  and  if  this  be  exhausted,  the  animal  dies  of  cold  (§  70). 

287.  To  recapitulate,  then,  the  sources  of  Carbonic  Acid  in  the  animal  body 
are  threefold.  —  I.  The  continual  decay  of  the  tissues  common  to  all  organized 
bodies,  which  is  favoured  by  whatever  promotes  their  vital  activity,  and  is  re- 
tarded by  every  influence  that  depresses  it.  —  n.  The  metamorphosis  peculiar  to 
the  Nervous  and  Muscular  tissues,  which  is  the  very  condition  of  the  production 
of  their  power,  and  which  therefore  bears  a  direct  relation  to  the  degree  in  which 
they  are  exerted.  —  in.  The  direct  conversion  of  the  carbon  and  hydrogen  of 
the  food  into  carbonic  acid  and  water,  which  is  peculiar  to  warm-blooded  ani- 
mals ;  and  which  varies  in  quantity,  in  accordance  with  the  amount  of  heat  to  be 
generated. 

288.  The  wonderful  nature  of  the  structural  arrangements  which  are  made 
for  the  aeration  of  the  blood  in  Man  (as  in  Mammalia  generally),  and  the  com- 
pleteness of  the  provisions  whereby  these  are  put  into  active  operation,  will  be 
best  understood,  if,  for  the  sake  of  contrast,  we  first  bestow  a  brief  survey  on  the 
Pulmonary  apparatus  of  Reptiles;  a  class  in  which  the  demand  for  respiration  is 
reduced  to  a  comparatively  low  grade,  by  the  absence  of  any  necessity  for  the 
maintenance  of  an  independent  temperature,  by  the  general  torpor  of  their  habits 
(whence  arises  a  very  small  amount  of  *  waste '  in  their  nervo-muscular  appa- 
ratus), and  by  the  very  slow  rate  at  which  their  organic  functions  are  performed 
and  the  life  of  the  whole  body  carried-on.  —  The  lungs  of  Reptiles  are,  for  the 
most  part,  simple  sacs ;  into  which  the  bronchial  tubes  open  freely,  and  on  the 
walls  of  which  the  pulmonary  vessels  are  distributed.     The  extent  of  surface  is 
considerably  increased,  however,  by  the  formation  of  a  number  of  little  pits  or 
sacculi  on  the  inner  wall  of  the  cavity,  especially  at  its  upper  part;  and  between 
these  we  observe  a  sort  of  cartilaginous  frame-work,  which  is  continuous  with  the 
cartilage  of  the  bronchus  on  either  side.     Thus  it  happens  that  the  network  .of 
pulmonary  capillaries  is  exposed  only  on  one  side  to  the  influence  of  the  air. 
The  general  distribution  of  these  vessels  is  shown  in  the  accompanying  figures. 
It  will  be  seen  that  the  trunk  of  the  pulmonary  artery  runs  along  one  side  of 
the  sac,  and  that  of  the  pulmonary  vein  along  the   other  (Fig.  74);  and  that 
numerous  branches  arise  from  the  former,  which  sub-divide  into  capillaries  that 
ramify  over  the  whole  surface,  and  then  reunite  into  small  veins  which  terminate 
in  the  latter.     The  islets  of  parenchyma  left  between  the  capillary  vessels  (Figs. 
75,  76),  are  seen  to  be  much  smaller  than  those  which  are  usually  to  be  observed 
in  the  systemic  circulation ;  so  that  the  membrane  is  more  copiously  traversed 
l>y  vessels,  than  almost  any  other  that  is  known.     The  walls  of  the  capillaries, 


GENERAL    STRUCTURE    OF   THE    RESPIRATORY    ORGANS. 


283 


FIG.  75. 


FIG.  74.  moreover,  are  much  thinner  than  those  of  the  systemic  cir- 

f  culation.  The  two  conditions  are  obviously  favourable  to 
the  exposure  of  the  largest  possible  quantity  of  blood  to  the 
influence  of  the  air;  but  as  the  surface  is  not  an  extensive 
one,  the  proportion  which  can  be  thus  exposed  at  any  one 
time  is  very  limited ;  and  the  arrangement  of  the  circulating 
apparatus  is  such,  that  the  blood  which  has  been  subjected 
to  the  respiratory  process  is  mingled  with  a  large  quantity  of 
impure  blood,  before  being  transmitted  to  the  body  generally. 
For  the  heart  of  Reptiles  has  oi:ly 
three  cavities,  a  single  ventricle  and 
two  auricles;  from  this  single  ven- 
tricle proceeds  a  truncus  arleriosus, 
which  distributes  a  mixed  blood  alike 
to  the  system  and  to  the  lungs,  the 
pulmonary  artery  often  bearing  but 
a  small  proportion  in  size  to  the  sys- 
temic trunks;  and  the  blood  return- 
ing by  the  pulmonary  and  systemic 
veins  respectively,  to  the  right  and 
left  auricles,  is  poured  by  them 
jointly  into  the  common  ventricle. — 
The  lungs  of  Reptiles  are  not,  like 
Lung  of  Triton  erista-  those  of  Mammals,  enclosed  in  a 
magnified  about  3  Distinct  cavity,  partitioned-off  from 
the  abdominal  by  the  interposition 
of  a  diaphragm ;  but  they  lie  in  iui- 


n  rtery 
vein. 


Portion  of  the  Lung  of 
Triton,  more  highly  mag- 
nified. 


Portion  of  the  Lung  of  a  living  Triton,  as  seen  with  the  power  of  150  diameters  :-a,  b,  pal- 
monary  vein,  receiving  blood  from  the  large  trunk  c,  and  a  smaller  vess< 


284  OF     RESPIRATION. 

mediate  contact  with  the  other  viscera :  and  the  mechanism  of  inspiration  ani 
expiration  is  consequently  far  less  complete,  than  it  is  in  animals  which  possess  a 
muscular  diaphragm  closing-iu  the  floor  of  the  thoracic  cavity,  and  capable,  by 
its  contraction,  of  largely  increasing  the  capacity  of  that  cavity,  In  fact,  many 
Reptiles  are  incapable  of  drawing-in  air,  and  can  only/orce  it  in  by  a  process 
resembling  deglutition.1 

289.  The  size  of  the  lungs  in  Man  and  the  Mammalia  is  far  smaller  in  pro- 
portion to  their  bulk,  than  it  is  in  most  Reptiles ;  but  this  diminution  is  more 
than  compensated  by  the  minute  subdivision  of  their  cavities,  by  the  peculiarity 
of  the  distribution  of  their  blood-vessels,  and  by  the  arrangements  whereby  a 
continual  and  rapid  interchange,  both  of  the  blood  and  of  the  air,  is  provided- 
fur. —  The  following  are  the  points  of.most  importance  in  the  structure  of  the 
Human  Lung.2     The  walls  of  the  bronchial  tubes  contain  distinct  longitudinal 

and  circular  layers  of  fibrous  structure ,   but  the  latter  alone, 
FIG.  77.  according    to    Prof.    Kolliker,    contain    muscular   fibre-cells, 

[The  muscular  fibres  which  exist  in  the  trachea  are  continued 
down  even  to  the  terminal  bronchi,  but  instead  of  filling  up 
the  gap  in  the  cartilaginous  framework,  posteriorly,  as  in  the 
trachea,  they  form  a  uniform  layer  encircling  the  canal,  but 
excessively  thin.  Fig.  77. — ED.]  These  tubes  divide  and 
subdivide,  like  the  branches  of  a  tree,  still  retaining  their 
ordinary  characters,  until  they  are  no  more  than  from  l-50th 
to  l-30th  of  an  inch  in  diameter;  and  in  those  the  longitu- 

dinal  and  annular  fibres,  together  with  the  ciliated  epithelium, 

Small  bronchial  come  to  an  abrupt  termination.  Beyond  this  boundary,  the 
tube  laid  open,  show-  tubular  form  of  the  air-passages  continued  from  the  bronchi 
ing  the  transverse  is  retained  for  some  distance  ;  but  it  is  gradually  changed  by 
menfoTthe^mu"™'  tlie  irregular  branching  of  the  passages,  and  by  the  increase 
lar  layer  andTts  dis~  °^  ^e  number  of  apertures  in  their  walls,  which  lead  to  the 
position  at  the  orifice  air-vesicles.  Thus,  at  last,  each  minute  division  of  the  air- 
<>f  a  branch.  From  passages  becomes  quite  irregular  in  form ;  air-vesicles  opening 
a  man  aet.  fifty.  [u^0  every  part  of  it,  and  almost  constituting  its  walls ;  until 
Magnified  2  diam.  ^  terminates,  almost  without  dilatation,  in  an  air-vesicle. 

From   Todcl  &  Bow-      mi  .     ,  ,'          .  r>    ^         •  •  ,     •  -,• 

m,,,,t  Inis  terminal  portion  ot  the  air-passage,  with  its  surrounding 

cluster  of  air-vesicles,  may  be  regarded  as  forming  a  sort  of 
lobule,  and  as  representing  the  entire  lung  of  a  Frog  or  other  Reptile ;  the  whole 
lung  of  the  Mammal  being  made-up  of  a  multitude  of  such  lobules,  which  are 
almost  exact  repetitions  of  each  other.  Those  vesicles  which  communicate 
directly  with  the  bronchial  tubes  and  intercellular  passages,  open  into  them  by 
large  circular  apertures ;  and  they  are  themselves  similarly  opened-into  by  other 
vesicles,  which  again  communicate  with  others  beyond  them  j  so  that  each  of  the 
openings  in  the  air-passage  leads  to  a  series  of  air-vesicles,  extending  from  it  to 
the  surface  of  the  lobule.  The  vesicles  which  communicate  most  directly  with 
the  air-passages,  are  more  minute,  and  have  a  closer  vascular  network,  than  those 
which  lie  nearer  the  surface  of  the  lobule ;  an  arrangement  which  is  in  beautiful 
harmony  with  the  relative  facility  of  renovation  of  the  air  which  they  respectively 
contain.  The  air-vesicles  have  also  lateral  apertures  into  each  other ;  so  that  all 
the  parts  of  any  one  lobule  freely  communicate  together. 

290.  The  walls  of  the  air-vesicles  are  formed  of  a  very  thin  and  transparent 
membrane  (Fig.  78,  c),  which  is  folded  sharply  at  the  orifices  of  communication, 
so  as  to  form  a  very  definite  border  to  them;  and  which  is  lined  by  an  epithelial 

1  For  an  account  of  the  principal  forms  of  Respiratory  apparatus  among  the  lower  Ani- 
mals, see  "  PRINC.  OF  COMP.  PHYS.,"  Chap,  vi.,  Am.  Ed. 

1  See  especially  the  Memoir  by  Mr.  Rainey  in  the  "  Med.-Chirurg.  Trans.,"  vol.  xxviii. ; 
and  Prof.  Kolliker's  "Manual  of  Human  Histology"  (Sydenham  Society),  vol.  ii.  pp. 

A68 — 178. 


GENERAL    STRUCTURE    OF   THE   RESPIRATORY    ORGANS. 


Air-cells  of  Human  Lung,  with  intervening  tissues : 
— a,  epithelium  ;  b,  elastic  trabeculae  ;  c,  membranous 
wall,  with  fine  elastic  fibres. 


layer  (a),  composed  of  minute  poly-  FIG.  78. 

gonal  cells  of  from  l-1600th  to 
1 -2250th  of  an  inch  in  diameter, 
and  from  l-2800th  to  l-3800th  of 
an  inch  in  thickness.  Between 
the  air-vesicles  is  a  kind  of  trabe- 
cular  tissue,  which  seems  to  be 
almost  entirely  composed  of  yellow 
elastic  fibres  (6) ;  and  some  of 
these  fibres  also  coalesce  with  the 
lining  membrane,  so  as  to  impart 
to  it  increased  strength  ;  this  being 
especially  the  case  around  the 
apertures  of  communication  be- 
tween the  contiguous  air-cells.  Tt 
is  only  between  the  lobular  groups 
of  air-vesicles,  that  connective  tis- 
sue exists  in  any  appreciable  quan- 
tity.— The  diameter  of  the  Human 
air-cells  is  about  twenty  times 
greater  than  that  of  the  capillaries 
which  are  distributed  upon  their 
parietes  ;  varying  (according  to  the 
measurement  of  Weber)  from  the 
l-200th  to  the  l-70th  of  an  inch.1 
It  has  been  calculated  by  M. 
Rochoux,  that  as  many  as  17,790 
air-cells  are  grouped  around  each  terminal  bronchus;  and  that  their  total  number 
amounts  to  no  less  than  600  millions.  The  capillary  plexus  (Fig.  79)  is  so  dis 
posed  between  the  two  layers 

which  form  the  walls  of  two  adja-  FIG.  79. 

cent  air-cells,  as  to  expose  one  of 
its  surfaces  to  each  ;  by  which  pro- 
vision the  full  influence  of  the  air 
upon  it  is  secured.  The  net-work 
of  vessels  is  so  close,  that  the 
diameter  of  the  meshes  is  scarcely 
so  great  as  that  of  the  capillaries 
which  enclose  them ;  indeed  it 
would  be  impossible  to  conceive  of 
a  method,  by  which  blood,  whilst 
still  retained  within  vessels,  should 
be  spread  over  a  large  surface  for 
r^ration.  And  if  not  restricted 
wirhin  vessels,  it  could  not  be 
ceaselessly  and  rapidly  driven-on 
by  the  propulsive  power  of  the 
heart,  which  acts  no  less  efficiently  upon  the  pulmonary  circulation  Than  upon  the 
systemic,  although  the  force  exerted  is  much  inferior,  the  resisting  power  being 
far  less,  in  consequence  of  the  shortness  of  the  circuit. 

[M.  Rossignol  has  recently  given  an  elaborate  description  of  the  pulmonary 
structure.  He  insists  particularly  on  the  ultimate  bronchial  ramifications  being 

1  The  dimensions  given  by  Moieschott  ("  De  Vesiculus  Pulmonutn  Malpighianis  ";  are 
very  much  less  than  these  ;  the  range  of  diameter  being  stated  by  him  at  between  l-120th 
and  l-1200th  of  an  inch.  The  Author's  own  observations,  however,  lead  him  to  regard 
Weber's  statement  as  very  near  the  truth:  and  that  of  Prof.  Kolliker  is  almost  precisely 
the  same. 


Arrangement  of  the  Capillaries  of  the  air-cells 
of  the  Human  Lung. 


286 


OF    RESPI RATION. 


in  shape  like  an  inverted   funnel,  and  he  terms  them  the  infundibula.     The 
cells,  forming  a  honeycomb  on  their  interior,  he  calls  the  alveoli  (Figs.  80  and 


FIG.  SO. 


FIG.  81. 


Thin  slice  from  the  pleural  surface  of  a  cat's  lung,  considerably  magnified.  At  the  thin  edge, 
bed,  alveoli  are  seen.  In  the  centre  (as  a)  where  the  slice  is  thicker,  alveoli  are  seen  on  the 
walls  of  infundibula.  From  Rossignol. 

Emphysema,  according  to  this  author,  seems  to  consist  in  a  distension  of  the 
passages  and  cells,  and  a  breaking  down  and  obliteration  of  the  septa,  first 
between  the  cells  of  the  same  passage  and  then  between  neighbouring  passages, 
and  even  between  contiguous  lobules. 

[The  diameter  of  the  lobular  passages  is  from  TJotn  *°  siu*^1  °^  an  incn  >  an(i 
that  of  the  cells  from  2UT)tn  to  30Z)t'1  °^  an  ^nc^  according 
to  our  measurements.  In  a  preparation  of  the  lung  of 
the  calf,  by  Professor  Retzins,  they  measure  ^^th;  and 
Dr.  W.  Addison  makes  them  from  2^gth  to  J^Q^  °^  an 
inch.— ED.'] 

291.  The  fibrous  coat  of  the  bronchial  tubes  possesses  a 
considerable  amount  of  muscular  contractility,  which  (ac- 
cording to  the  experiments  of  Dr.  C.  J.  B.  Williams2) 
may  be  excited  by  electrical,  chemical,  or  mechanical 
stimuli,  applied  to  themselves;  but  this  is  not  so  readily 
excitable  through  their  nerves,  although  the  experiments 
of  Volkmann3  and  Longet4  have  clearly  shown  the  possi- 
bility of  thus  calling  it  into  action.  This  contractility 
resembles  that  of  the  intestines  or  arteries,  more  than  that 
of  the  voluntary  muscles  or  heart;  the  contraction  and 
relaxation  being  more  gradual  than  that  of  the  latter, 
though  less  tardy  than  that  of  the  former.  It  is  chiefly 
manifested  in  the  smaller  bronchial  tubes,  those  of  less  than  a  line  in  diameter 
having  been  seen  to  contract  gradually  under  the  stimulus  of  galvanism,  until  their 
cavity  was  nearly  obliterated ;  on  the  other  hand,  in  the  trachea  and  larger  bron- 
shi,  the  cartilaginous  rings  prevent  any  decided  diminution  in  the  calibre  of  the 
tubes,  and  the  muscular  structure  is  much  less  distinct.  It  is  remarked  by  Dr. 
Williams,  that  the  contractility  of  the  bronchial  muscles  is  soon  exhausted  by  the 
action  of  the  stimulus  j  but  that  it  may  in  some  degree  be  restored  by  rest,  even 

1  "  Physiological  Anatomy,"  by  Todd  and  Bowman,  Am.  Ed. 

*  "Report  of  the  British  Association  for  1840,"  p.  411. 

*  "  Wagner's  Handworterbuch,"  bandii.,  Art.  '  Nervenphysiologie,'  §  586. 
'•  \nat.  et  Physiol   du  Systeme  Nerveux,"  torn.  ii.  p.  289. 


Bronchial  termination 
in  the  lung  of  the  dog. 
a.  Tube  (lobular  pas- 
sage) branching  towards 
the  infundibula.  b.  One 
of  the  infundibula.  c. 
Septa  projecting  in- 
wards on  the  infundi- 
bular wall  and  forming 
the  alveoli,  or  cells. 
From  Rossignol.] 


GENERAL   STRUCTURE    OF   THE   RESPIRATORY    ORGANS.  287 

when  the  lung  is  removed  from  the  body.  When  the  stimulation  is  long  con- 
tinued, however,  as  by  intense  irritation  of  the  mucous  membrane  during  life,  the 
contractile  tissue  passes  into  a  state  which  resembles  the  tonic  contraction  of  mus- 
cular fibre.  The  contractility  is  greatly  affected  by  the  mode  of  death,  and  is  re- 
markably diminished  by  the  action  of  vegetable  narcotics,  particularly  stramonium 
and  belladonna  :  whilst  it  seems  to  be  scarcely  at  all  affected  by  hydrocyanic  acid. 
— These  facts  are  very  important,  as  throwing  light  upon  certain  diseased  con- 
ditions. It  has  long  been  suspected,  that  the  dyspnoea  of  Spasmodic  Asthma 
depends  upon  a  constricted  state  of  the  smaller  bronchial  tubes,  excited  through 
the  nervous  system,  frequently  by  a  stimulating  cause  at  some  distance  ;  and 
there  can  be  now  little  doubt  that  such  is  the  case.  The  peculiar  influence  of 
stramonium  and  belladonna,  in  diminishing  the  contractility  of  these  fibres,  har- 
monizes remarkably  with  the  well-known  fact  of  the  relief  frequently  afforded  by 
them  in  this  distressing  malady.  It  seems  not  improbable  that  this  contractility 
of  the  bronchial  tubes  may  serve  to  regulate  the  supply  of  air  to  the  lobules,  in 
accordance  with  the  wants  of  the  system,  just  as  the  contractility  of  the  minute 
arteries  regulates  the  supply  of  blood  to  the  organs  to  which  they  proceed;  and 
it  may  possibly  be  through  this  channel,  that  the  remarkable  variation  is  effected 
in  the  amount  of  respiration,  which  adapts  the  quantity  of  heat  produced  to  the 
depression  of  the  external  temperature  (§  286).  It  has  been  further  suggested 
by  Dr.  W.  T.  Gairdner,1  that  the  contractility  of  the  smaller  bronchi  may  serve 
to  expel  collections  of  mucus  which  have  accumulated  in  them,  and  which 
neither  ciliary  action  nor  the  ordinary  expiratory  efforts  suffice  to  displace.2 

292.  Although  there  is  no  sufficient  reason  to  believe  that  the  Lungs  are 
possessed  of  any  power  of  vital  contractility,  yet  their  Elasticity  prevents  them 
from  being  altogether  passive  agents  in  the  respiratory  operation.  The  elastic 
tension  is  rapidly  increased  by  the  dilatation  of  the  lungs  with  air;  and  the  care- 
fully-conducted experiments  of  Dr.  Hutchinson3  lead  him  to  estimate  it  at  cer- 
tainly not  less  than  £  Ib.  upon  each  square  inch  of  surface,  when  the  lungs  have 
been  filled  by  the  deepest  possible  inspiration;  so  that  its  whole  amount  (reckon- 
ing an  average  surface  of  300  sq.  in.  for  the  male,  and  247  sq.  in.  for  the  female) 
will  be  not  less  than  150  Ibs.  for  the  male,  and  123 £  Ibs.  for  the  female.  This 
force  is  exerted  in  aid  of  the  expiratory  movement,  and  is  directly  antagonistic 
lo  the  ^?^spiratory ;  so  that  the  inspiratory  muscles  must  overcome  it,  in  order  to 
produce  complete  distension  of  the  pulmonary  cavities.  This  distension  is 
entirely  accomplished  by  the  action  of  the  muscles  external  to  the  thorax,  or 
partly  forming  its  parietes.  The  lung  completely  fills  the  cavity  of  the  pleura, 
in  the  healthy  state  at  least;  so  that  when  this  is  enlarged,  a  vacuum  would  be 
produced,  if  it  were  not  occupied  by  a  corresponding  enlargement  of  the  lung; 
and  to  effect  this,  the  air  rushes  down  the  trachea,  and  thence  passes  into  the 
entire  substance  of  the  lung,  which  it  fills  out  in  every  dimension.  This  disten- 
sion is  much  more  complete  than  any  that  could  be  occasioned  by  simple  insuf- 
flation from  the  trachea  •  for  long  before  the  internal  pressure  could  overcome 
the  resistance  set-up  by  the  elasticity  of  the  lungs,  and  still  more  by  that  of  the 
parietes  of  the  chest  (§  295),  to  the  full  dilatation  of  the  air-vesicles,  the  tissue 
of  the  lung  itself  would  be  almost  certain  to  give  way.  This  has  actually  hap- 
pened in  numerous  instances ;  and  it  constitutes  a  very  forcible  objection  to  the 
use  of  any  apparatus  for  artificial  respiration,  whose  action  is  that  of  'insuffla- 
tion.' 

1  "Edinburgh  Monthly  Journal,"  May,  1851. 

J  It  has  been  maintained  by  Dr.  Radclyffe  Hall  ("  Transactions  of  Provincial  Medical 
Association,"  1850),  that  the  contractility  of  the  bronchial  tubes  is  called  into  action  in 
each  expiratory  movement,  to  assist  in  emptying  the  lungs.  But  no  evidence  has  been 
adduced  in  support  of  this  doctrine :  and  its  improbability  is  apparent  from  the  obvious 
fact,  that  a  contraction  of  the  air-tubes  would  impede,  rather  than  promote,  the  emytving 
cf  the  air-vesicles. 

'  i% Cyclopaedia  of  Anatomy,"  Art.  'Thorax,'  vol.  iv.  p.  1058. 


288 


OF    RESPIRATION. 


293.  The  complete  dependence  of  the  expansion  of  the  Lungs  upon  the  en 
largement  of  the  cavity  of  the  chest,  is  well  shown  by  the  effect  of  admission 
of  air  into  the  pleural  cavity.      When  an  aperture  is  made  on  either  side,  so  that 
the  air  rushes-in  at  each  inspiratory  movement,  the  expansion  of  the  lung  on  that 
side  is  diminished,  or  entirely  prevented,  in  proportion  to  the  size  of  the  aperture. 
If  air  can  enter  through  it  more  readily  than  through  the  trachea,  an  entire  col- 
lapse of  the  lung  takes  place ;  and  by  making  such  an  aperture  on  each  side, 
complete  asphyxia  is  produced.     But  if  it  be  too  small  to  admit  the  very  ready 
passage  of  air,  the  vacuum  produced  by  the  inspiratory  movement  is  more  easilv 
filled  by  the  distension  of  the  lungs,  than  by  the  rush  of  air  into  the  pleural 
cavity ;  so  that  a  sufficient  amount  of  change  takes  place  for  the  maintenance  of 
life.    This  is  frequently  observed  in  the  case  of  penetrating  wounds  of  the  thorax, 
in  the  surgical  treatment  of  which,  it  is  of  great  importance  to  close  the  aperture 
as  completely  as  possible;  when  this  has  been  accomplished,  the  air  that  had 
found  its  way  into  the  cavity  is  soon  absorbed,  and  the  lung  resumes  its  full  play. 
Where  one  lung  is  obstructed  by  tubercular  deposit,  or  is  prevented  in  any  other 
way  from  rightly  discharging  its  function,  an  opening  that  freely  admits  air  into 
the  pleural  cavity  of  the  other  side,  is  necessarily  attended  with  an  immediately- 
fatal  result;  and  in  this  manner  it  not  unfrequently  happens  that  chronic  pul- 
monary diseases  suddenly  terminate  in  Asphyxia,  a  communication  being  opened 
by  ulceration  between  a  bronchial  tube  and  the  cavity  of  the  thorax. 

294.  Of  the  Respiratory  Movements.  —  The  dilatation  of  the  Pleural  cavity 
during  Inspiration,  is  chiefly  accomplished  by  the  contraction  of  the  Diaphragm, 
which,  from  the  high  arch  that  it  previously  formed,  becomes  nearly  plane  j  in 
this  change  of  figure,  it  presses  on  the  abdominal  viscera,  so  as  to  cause  them  to 
protrude,  which  they  are  enabled  to  do  by  the  relaxation  of  the  abdominal  mus- 
cles.    In  ordinary  tranquil  breathing  (especially  in  children),  the  action  of  the 
diaphragm  is  alone  nearly  sufficient  to  produce  the  necessary  exchange  of  air ; 
but,  when  a  full  inspiration  is  required,  the  cavity  of  the  chest  is  dilated  laterally 
and  antero-posteriorly,  as  well  as  inferiorly.     The  enlargement  of  the  chest  in 
both  these  directions  is  effected  by  the  elevation  of  the  ribs;  for  whilst,  in  the 
undilated  state  of  the  thorax,  the  ribs  form  an  angle  with  their  cartilages,  which 
becomes  less  and  less  obtuse  as  we  pass  from  the  first  rib  downwards,  the  eleva- 
tion of  the  ribs  tends  to  bring  them  and  their  cartilages  more  nearly  into  a  line, 

and  thus  separates  them  more  widely 


[FiG.  82. 


FIG.  83. 


from  the  median  plane,  and  at  the 
same  time  causes  them  to  push  for- 
wards the  sternum.  Owing  to  the 
greater  length  of  the  lower  true  ribs, 
and  the  greater  obliquity  of  their 
junction  with  their  cartilages,  both 
these  changes  are  more  considerable 
in  the  lower  part  of  the  thorax  than 
in  the  upper ;  and  this  is  especially 
the  case  in  adult  men,  whose  respi- 
ration has  been  designated  as  ( infe- 
rior costal,'  whilst  in  females  the 
mobility  of  the  first  rib  and  of  the 
whole  of  the  upper  part  of  the  tho- 
rax is  greater,  so  that  their  respira- 
tion may  be  designated  as  l  superior 
costal/  (Figs.  82,  83.)  — The  tho- 
racic muscles  whose  contraction 
participates  in  the  ordinary  move- 
ments of  Inspiration,  are  (according 
]  to  Dr.  Hutchinson,  Op.  cit.;  p.  1055) 


OF    THE    RESPIRATORY    AoVEMENTS.  280 

the  external  intercostal,  with  those  portions  of  the  internal  intercostals  which 
pass  between  the  cartilages,  the  levatores  costarum,  and  a  portion  of  the  triangu- 
laris  sterni,  all  of  which  have  the  same  action,  that  of  elevating  the  ribs.  On 
the  other  hand,  the  thoracic  Expiratory  muscles  are  the  proper  costal  portion  of 
the  internal  intercostals,  with  the  infracostals,  and  a  part  of  the  triangularis 
sterni.  The  respiratory  movement  will  be  assisted  also  by  the  abdominal  mus- 
cles, which  antagonize  the  diaphragm  by  pressing-back  the  abdominal  viscera, 
and  thus  causing  its  ascent  so  soon  as  it  has  become  relaxed.  There  are  many 
accessory  muscles,  however,  which  take  a  share  in  violent  respiratory  movements, 
both  inspiratory  and  expiratory.  Thus  all  the  muscles  which  elevate  the  scapula, 
may  act  through  it  upon  the  ribs,  and  the  scaleni  act  directly  upon  the  first  rib ; 
whilst  all  those  which  erect  the  spine,  fix  more  perfectly  the  origins  of  these  and 
other  muscles  which  are  to  act  upon  the  thorax.  So,  again,  the  expiratory  move- 
ment is  aided  by  the  longissimus  dorsi,  sacrolumbalis,  and  other  muscles  which 
tend  to  depress  the  ribs.  In  difficult  respiration,  almost  every  muscle  in  the  body 
is  made  in  some  way  subservient  to  the  distension  of  the  chest;  thus,  a  patient 
suffering  under  urgent  dyspnoea  instinctively  lays  hold  of  some  fixed  object,  so  as 
to  prevent  his  upper  extremities  from  moving;  and  thus  his  scapula  becomes  a 
fixed  point,  from  which  the  pectorales  (major  and  minor)  and  serratus  magrius 
can  aid  in  elevating  the  ribs. 

295.  The  relative  amount  of  muscular  force  which  is  required  for  these  two 
movements  respectively,  is  affected  in  a  very  remarkable  manner  by  the  elasticity 
of  the  walls  of  the  thoracic  cavity ;  for  this  (like  the  elasticity  of  the  lungs) 
supplies  a  force  which  greatly  aids  the  expiratory  movement,  whilst  it  offers  a 
corresponding  opposition  to  the  «?spiratory.  Here,  also,  the  degree  of  force 
exerted  increases  very  rapidly  with  the  degree  of  distension.  Thus  in  a  body 
experimented-on  by  Dr.  Hutchinson  (Op.  cit.,  p.  1056),  the  following  were  the 
relations  between  the  amount  of  air  forced-in,  the  resisting  elasticity,  as  shown 
by  the  height  of  mercury  supported,  the  actual  pressure  upon  each  square  inch 
of  surface  which  this  indicated,  and  the  total  pressure  over  the  surface  of  the 
chest,  reckoning  its  area  at  206  square  inches : — 

Pressure  in  height      Pressure  Total 

Cubic  inches.  of  Mercury.  per  sq.  in.  Pressure 

Air  forced  in     .       70  Resisting  elasticity  1-00  inch.  7-8  oz.  104-4  Ibs. 

90          "              «  1-50     "  11-7  "  150-6    « 

"                    180          "              "  3-25     "  25-3  "  326-3    " 

200          "              "  4-50     "  35-1  "  451-9   « 

To  this  451-9  Ibs.  must  be  added  at  least  128  Ibs.  for  the  elastic .  force  of  the 
lungs  themselves  at  that  degree  of  distension,  making  altogether  580  Ibs. ;  and 
as  the  subject  of  this  observation  could  expire  during  life  considerably  more  air 
than  the  highest  amount  forced  into  his  chest  after  death,  there  can  be  little 
doubt  (judging  from  the  rapid  ratio  in  which  the  elastic  force  increases  when 
the  distension  is  approaching  its  limits)  that  the  muscular  power  required  to 
overcome  this,  towards  the  close  of  a  very  deep  inspiration,  could  not  have  been 
less  than  1000  Ibs.  The  co-operation  of  the  elastic  resistance  with  the  expira- 
tory movement,  and  its  antagonism  to  the  inspiratory,  is  doubtless  the  principal 
cause  why  the  power  of  the  expiratory  muscles,  as  tested  by  the  height  of  the 
column  of  mercury  supported  by  the  air,  should  always  be  greater  than  that  of 
the  inspiratory  muscles  (see  Dr.  Hutchinson,  Op.  cit.,  p.  1061);  and  why  the 
expiratory  power  should  be  very  much  greater  when  the  chest  has  been  well 
filled  with  air,  than  when  it  is  comparatively  empty.  The  following  is  given  by 
Dr.  Hutchinson  as  the  range  through  which  these  powers  may  vary  within  the 
limits  of  health  : — 
19 


290  OF    RESPIRATION. 

Power  of  Power  of 

Inspiratory  Muscles.  Expiratory  Muscles. 

1-5  inch.  Weak 2-0  inches. 

2-0  Ordinary 2-5 

2-5  Strong 3-5 

3-5  Very  strong  4-5 

4-5  Remarkable  5-8 

5-5  Very  remarkable  7-0 

6-0  Extraordinary  8-5 

7-0     "  Very  extraordinary  10-0 

The  expiratory  power  may  be  augmented  by  the  habitual  performance  of  move- 
ments in  which  they  participate ;  and  thus  the  inspiratory  power  is  the  preferable 
test  of  the  vis  vitce.  This  has  been  found  by  Dr.  Hutchinson  to  bear  some  rela- 
tion to  height,  being  greatest  (on  an  average  of  a  considerable  number  of  cases) 
when  the  stature  is  5  feet  7  or  8  inches;  and  diminishing  above  that  height,  as 
well  as  below  it. 

296.  It  is  impossible  to  form  a  correct  estimate,  by  observations  on  one's-self, 
of  the  usual  Number  and  extent  of  the  respiratory  movements ;  since  the  direc- 
tion of  the  attention  to  them  is  certain  to  increase  their  frequency  and  amount. 
In  general  it  may  be  stated,  that  from  16  to  20  alternations  usually  occur  in  a 
minute ; l  of  these,  the  ordinary  inspirations  involve  but  little  movement  of  the 
thorax;  but  a  greater  exertion  is  made  at  about  every  fifth  recurrence.     The 
average  numerical  proportion  of  the  respiratory  movements  to  the  pulsations  of 
the  heart,  is  about  1  :  5,  1  :  4£,  or  1  :4;  and  when   this  proportion  is  widely 
departed-from,  there  is  reason  to  suspect  some  obstruction  to  the  aeration  of  the 
blood,  or  some  disorder  of  the  nervous  system.     Thus  in  Pneumonia,  in  which  a 
greater  or  less  amount  of  the  lung  is  unfit  for  its  office,  the  number  of  respira- 
tions increases  in  a  more  rapid  proportion  than  the  acceleration  of  the  pulse ;  so 
that  the  ratio  becomes  as  1  to  3,  or  even  1  to  2,  in  accordance  with  the  degree 
of  engorgement.2     In  Hysterical  patients,  however,  a  similar  increase,  or  even  a 
greater  one,  may  take  place  without  any  serious  cause;  thus  Dr.  Elliotson3  men- 
tions a  case  in  which  the  respiratory  movements  of  a  young  female,  through 
nervous  affection,  were  98  or  even  106,  whilst  the  pulse  was  104.     On  the  other 
hand,  the  respirations  in  certain  typhoid  conditions  and  in  narcotic  poisoning 
become  abnormally  slow,  owing  to  the  torpid  condition  of  the  nervous  centres, 
the  proportion  being  1  to  6,  or  even  1  to  8 ;  and  in  such  cases,  the  lungs  not 
unfrequently  become  cedematous,  from  a  cause  hereafter  to  be  mentioned  (307). 

297.  Not  only  the  rate  of  the  Respiratory  movements,  but  also  their  extent, 
is  affected  by  various  morbid  conditions;   thus  when  dislocation  of  the  spine 
takes  place  above  the  origin  of  the  intercostal  nerves,  but  below  that  of  the 
phrenic,  so  that  the  former  are  paralysed,  the  respiratory  movement  is  confined 
to  the  diaphragm :  and  as  this  is  insufficient,  serum  is  effused  into  the  lungs,  and 
a  slow  Asphyxia  supervenes,  which  usually  proves  fatal  in  from  three  to  seven 
days.     Even  where  the  muscles  and  nerves  are  all  capable  of  action,  the  full 
performance  of  the  inspiratory  movements  is  prevented,  by  the  solidification  or 
engorgement  of  any  part  of  the  lung,  which  interferes  with  its  free  distension  ; 
or  by  adhesions  between  the  pleural  surfaces,  which  offer  a  still  more  direct  im- 
pediment.    When  these   adhesions  are   of  long  standing,  they  are  commonly 
stretched  into  bands,  by  the  continual  tension  to  which  they  are  subjected.     If 
the  impeding  cause  affect  both  sides,  the  movements  of  both  will  be  alike  inter- 
fered-with ;  but  if  one  side  only  be  affected,  its  movements  will  be  diminished, 
whilst  those  of  the  other  remain  natural ;   and  the  physician  hence  frequently 

1  See  Dr.  Hutchinson's  Table,  in  "Cyclop,  of  Anat.  and  Phys.,"  vol.  iv.,  p.  1085. 

3  See  a  Paper  by  Dr.  Hooker,  on  the  '  Relation  between  the  Respiratory  and  Circulating 
Functions,'  in  the  "  Boston  (N.  E.)  Medical  and  Surgical  Journal;"  an  abstract  of  which 
^ill  be  found  in  the  '•  British  and  Foreign  Medical  Review,"  vol.  iv.,  p.  263. 

3  "  Physiology,"  p.  215,  note. 


OF    THE    KESPIRATORY    MOVEMENTS.  291 

derives  an  indication  of  great  value,  in  regard  to  the  degree  in  which  the  lung 
has  become  incapable  of  performing  its  functions.  It  is  to  be  remembered,  how- 
ever, that  the  action  both  of  the  diaphragm  and  of  the  elevators  of  the  ribs  may 
be  prevented,  by  pain  either  in  the  muscles  themselves  or  in  the  parts  which 
they  move ;  thus  the  descent  of  the  diaphragm  is  checked  by  inflammation  of  the 
abdominal  viscera  or  of  the  peritoneum;  and  the  play  of  the  intercostals  by 
rheumatism,  pleuritis,  pericarditis,  or  other  painful  disorders  of  the  parts  form- 
ing the  parietes  of  the  -thorax. 

298.  We  have  now  to  inquire  into  the  mode  in  which  the  Muscular  move- 
ments of  Respiration  are  kept-up  by  Nervous  power. — There  can  be  no  doubt 
that  these  movements,  though  partly  under  the  control  of  the  Will,  are  essentially 
'  automatic'  in  their  nature.     Their  chief  centre  is  the  upper  part  of  the  Medulla 
Oblongata,  into  which  may  be  traced  the  principal  excitor  nerves  that  convey  the 
stimulus  on  which  the  movements  are  dependent,  whilst  from  it  proceed  the 
principal  motor  nerves  by  which  they  are  carried  into  effect.     And  thus  it  hap- 
pens that  the  whole  of  the  Encephalon  may  be  removed  from  above,  and  the 
Spinal  cord  (as  far  up  as  the  origin  of  the  phrenic  nerve)  from  below,  without 
suspending  the  most  essential  of  the  respiratory  movements.    But  other  parts  of 
the  automatic  centres  are  concerned  in  the  ordinary  movements  of  respiration ; 
and  there  is  probably  no  part  that  may  not  be  excited  to  action,  by  the  extra- 
ordinary stimulus  which  results  from  a  prolonged  interruption  to  the  aeration  of 
the  blood  (§  294). 

299.  The  chief  '  excitor'  of  the  respiratory  movements  is  unquestionably  the 
Pneumogastric  nerve.     When  this  is  divided  on  both  sides,  according  to  the  ex- 
periments of  Dr.  J.  Reid,'  the  number  of  respiratory  movements  is  considerably 
diminished,  usually  by  about  one-half.     Now  if  this  nerve  excites  the  motions 
of  respiration  by  its  powerful  action  in  producing  sensation,  we  should  expect  to 
find  its  trunk  endowed  with  considerable  sensibility,  which  is  not  the  case ;  for 
all  experimenters  agree  in  stating,  that,  when  its  trunk  is  pinched  or  pricked,  the 
animal  does  not  exhibit  signs  of  pain  nearly  so  acute,  as  when  the  trunks  of  the 
ordinary  spinal  nerves,  or  of  the  fifth  pair,  are  subjected  to  similar  treatment. 
It  cannot  be  questioned,  however,  that  its  power  as  an  excitor  of  respiration  is 
very  great;  since,  besides  the  fact  of  the  diminution  in  the  number  of  inspira- 
tions which  occurs  immediately  on  section  of  it,  irritation  of  its  trunk  in  the 
neck  is  instantly  followed  by  an  act  of  inspiration.     It  is  evident  that  this  power 
must  arise  from  impressions  made  upon  its  peripheral  extremities.     The  impres- 
sion is  probably  due  to  the  presence  of  venous  blood  in  the  capillaries  of  the 
lungs ;  or,  as  Dr.  M.  Hall  thinks,  to  the  presence  of  carbonic  acid  in  the  air-cells. 
Either  or  both  may  be  true. — The  Pneumogastric  nerve,  however,  is  not  the  only 
'  excitor'  of  the  respiratory  movements ;  since,  when  the  nerve  is  cut  on  each  side, 
these  still  continue,  though  with  diminished  frequency.     The  removal  of  thtf 
Encephalon  lessens  the  frequency  of  the  respiratory  movements,  whether  it  bo 
performed  before  or  after  the  section  of  the  Vagi.     Dr.  Reid  found  that  in  a 
kitten  of  a  day  old,  in  which  the  inspirations  had  been  100  per  minute,  they  fell 
to  40  when  the  Encephalon  was  removed ;  and  on  subsequently  cutting  the  Pneu- 
mogastrics,  the  number  of  inspirations  instantly  fell  to  between  3  and  4  in  the 
minute,  and  continued  so  for  some  time.     Hence  it  has  been  supposed  that  the 
respiratory  movements  are  partly  dependent  upon  sensation,  a  motor  influence 
being  excited  by  it ;  but  it  may  be  fairly  surmised,  from  the  close  dependence 
of  nervous  activity  upon  the  oxygenation  of  the  blood,  that  a  '  besoin  de  respirer' 
may  originate  in  the  circulation  of  imperfectly-aerated  blood   in   the  nervous 
centres  themselves,  and  may  become  the  direct  excitor  of  respiratory  movements. 

1  "Edinb.  Med.  and  Surg.  Journ.,"  vol.  li. ;  ani  "Phys.,  Anat.,  and  Pathol.  Res.,"  p. 
177 — Dr.  Reid  has  satisfactorily  shown  the  statement  of  many  experimenters,  that  the 
inspirations  are  increased  in  frequency  after  this  operation,  to  be  erroneous ;  this  idea 
having  originated  in  the  very  prolonged  and  laborious  character  of  the  movements. 


292  OF    RESPIRATION. 

800.  But  why  (it  may  be  asked)  do  the  movements  continue,  when  the  Pneu- 
mogas tries  have  been  divided,  and  the  Encephalon  has  been  removed  ?  It  is 
evident  that  there  must  be  other  exciters  to  the  action  of  the  respiratory  muscles. 
Amongst  these,  the  nerves  distributed  to  the  general  surface,  and  particularly  to 
the  face,  probably  perform  an  important  part;  and  in  exciting  the  first  inspira- 
tion, the  Fifth  pair  seems  the  principal  agent.  It  has  long  been  a  well-known 
fact,  that  the  first  inspiratory  effort  of  the  new-born  infant  is  most  vigorously 
performed,  when  the  cool  external  air  comes  into  contact  with  the  face ;  and  that 
impressions  on  the  general  surface,  such  as  a  slap  of  the  hand  on  the  nates,  are 
often  effectual  in  exciting  the  first  inspiratory  movements,  when  they  would  not 
otherwise  commence.  Dr.  M.  Hall  relates  an  interesting  case,  in  which  the  first 
inspiration  was  delayed,  simply  because  the  face  was  protected  by  the  bed-clothes 
from  the  atmosphere;1  and,  on  lifting-up  these,  the  infant  immediately  breathed. 
Dr.  M.  Hall  has  also  mentioned  the  important  fact,  that  although,  if  the  cere- 
brum be  removed,  and  the  pneumogastrics  be  divided,  in  a  young  kitten,  the 
number  of  acts  of  respiration  will  be  reduced  to  four  in  a  minute,  yet  by  direct- 
ing a  stream  of  air  on  the  animal,  or  by  irritating  various  parts  of  the  general 
surface,  we  may  excite  twenty  or  thirty  acts  of  respiration  within  the  same  space 
of  time.  He  further  remarks,  that  in  the  very  young  warm-blooded  animals,  as 
An  the  cold-blooded  animal,  the  phenomena  of  the  excito-motor  power  are  far 
more  vividly  manifested,  than  in  the  older  and  warm-blooded.  In  the  very  young 
kitten,  even  when  asphyxiated  to  insensibility,  every  touch,  contact,  or  slight 
blow,  every  jar  of  the  table,  any  sudden  impression  of  the  external  air,  or  that 
of  a  few  drops  of  cold  water,  induces  at  once  energetic  reflex  movements  and  acts 
of  inspiration.  This  may  be  looked  upon  as  Nature's  provision  for  the  first  es- 
tablishment of  the  respiratory  function  in  the  new-born  animal. — But  the  in- 
fluence of  the  nerves  of  the  general  system  is  by  no  means  wanting  in  the  adult ; 
as  many  familiar  facts  demonstrate.  Thus  every  one  knows  that  the  first  plunge 
into  cold  water,  or  the  first  descent  of  the  streams  of  the  shower-bath,  or  even 
the  dashing  of  a  glass  of  cold  water  in  the  face,  will  produce  inspiratory  efforts; 
and  this  fact  has  many  important  practical  applications.  Thus  in  the  treatment 
of  Asphyxia,  whether  congenital,  or  the  result  of  narcotic  poisoning,  drowning, 
&c.,  the  alternate  application  of  cold  and  heat  is  found  to  be  one  of  the  most 
efficacious  means  of  restoring  the  respiratory  movements;  and  a  paroxysm  of 
hysteric  laughter  may  be  cut-short,  by  dashing  a  glass  of  cold  water  in  the  face. 
One  of  Dr.  Reid's  experiments  strikingly  demonstrates  the  variety  of  the  pro- 
visions that  have  been  made  for  the  performance  of  this  function.  After  dividing 
the  pneumogastrics,  and  removing  the  cerebrum  and  cerebellum,  he  divided  the 
spinal  cord  high-up  in  the  neck,  so  as  to  cut-off  the  communication  between  the 
spinal  nerves  and  the  Medulla  Oblongata;  and  he  found  that  the  frequency  of 
the  respiratory  movements  was  still  further  diminished,  although  they  were  not 
even  then  entirely  suspended ;  their  continuance,  after  every  channel  of  excita- 
tion appeared  to  have  been  cut  off,  being  probably  dependent  (as  he  himself  sug- 
gested) on  the  circulation  of  imperfectly-aerated  blood  in  the  Medulla  Oblongata. 
— It  seems  not  improbable  that  even  the  Sympathetic  nerve,  which  derives  many 
filaments  from  the  Cerebro-Spinal  system,  and  which  especially  communicates 
with  the  Pneumogastric  nerves,  may  be  one  of  the  exciters  to  this  function ;  and 
this,  perhaps,  not  only  through  its  ramifications  in  the  lungs,  which  are  consider- 
able, but  also  by  its  distribution  on  the  systemic  vessels;  so  that  it  may  convey 
to  the  Spinal  Cord  the  impression  of  imperfectly-arterialized  blood  circulating 
through  these,  such  as  the  Pneumogastric  is  believed  to  transmit  from  the  lungs. 

301.  The  motor  or  'efferent7  nerves  concerned  in  the  function  of  Eespiration, 

are  those  which  Sir  C.  Bell  has  grouped-together  in  his  '  respiratory  system.' 

The  most  important  of  these,  the  Phrenic,  arises  from  the  upper  part  of  the 

•Spinal  Cord;  the  Intercostals  much  lower  down;  whilst  the  Facial  nerve  and  the 

1  "  New  Memoir  on  the  True  Spinal  Marrow,"  &c.,  p.  29. 


OF    THE    RESPIRATORY    MOVEMENTS.  293 

Spinal  Accessory,  to  the  latter  of  which,  as  will  be  shown  hereafter,  (CHAP.  xi. 
Sect.  2),  the  motor  powers  of  the  Pneumogastric  are  chiefly  due,  take  their  origin 
in  the  Medulla  Oblongata  itself.  But  we  must  not  decide  upon  the  connection 
of  a  particular  nerve  with  a  particular  segment  of  the  Spinal  Cord,  simply  ( 
because  it  diverges  from  it  at  that  point;  and  the  analogy  of  the  Invertebrated 
classes  favours  the  idea,  that  a  direct  structural  connection  exists  between  the 
ganglionic  centre  of  the  Respiratory  movements,  and  the  nerves  which  transmit 
their  influence  to  the  muscles.  Upon  this  point,  however,  it  is  unsafe  to  specu- 
late ;  and  we  can  only  state  it  as  a  possibility,  that  some  such  connection  may  be 
established  in  Vertebrated  animals  through  the  white  columns  of  the  spinal 
cord. 

302.  That  the  Respiratory  movements,  as  ordinarily  performed,  are  essentially 
independent  of  the  Will,  appears  not  only  from  our  own  consciousness,  but  also 
from  cases  of  paralysis ;  in  some  of  which,  the  power  of  the  will  over  the  muscles 
has  been  lost,  whilst  the  movements  have  been  kept-up  by  the  reflex  action  of 
the  Medulla  Oblongata  or  respiratory  ganglion ;  whilst  in  others,  some  of  the 
respiratory  muscles  have  been  motionless  during  ordinary  breathing,  and  yet  have 
remained  under  the  power  of  the  will.1     That  Consciousness  is  not  a  necessary 
link  in  the  chain   of  causes  which  produce  the   respiratory  movements,  we  are 
enabled  to  judge  from  the  phenomena  presented  by  the   human  being  in  sleep 
and  coma,  by  anencephalous  foetuses,  and  by  decapitated  animals.     This  conclu- 
sion is  confirmed  by  a  case  recorded  by  Dr.  H.  Ley,2  who  had  under  his  care  a 
patient  in  whom  the  pneumogastrics  appeared  to  be  diseased  ;  the  lungs  suffered 
in  the  usual  way  in  consequence,  and  the  patient  had  evidently  laborious  breath- 
ing; but  he  distinctly  said  that  he  felt  no  uneasiness  in  his  chest. — The  expe- 
rience of  every  one  informs  him,  however,  that  the  Respiratory  movements  are 
partly  under  the  control  of  the  will,  though  frequently  unrestrainable  by  it.     In 
ordinary  circumstances,  when  the  blood  is  being  perfectly  aerated,  and  there  is  a 
sufficient  amount  of  arterial  blood  in  the  system  to  carry-on  the  functions  of  life 
for  a  short  time,  we   can  suspend  the  respiratory  actions  during  a  few  seconds 
without  any  inconvenience.     If,  however,  we  endeavour  to  prolong  the  suspen- 
sion, the  stimulus  conveyed  by  the  excitor  nerves  to  the  Medulla  Oblongata 
becomes  too  strong,  and  we  cannot  avoid  making  inspiratory  efforts;  and  if  the 
suspension  be  still  further  prolonged,  the  whole  body  becomes  agitated  by  move- 
ments which  are  almost  of  a  convulsive  nature,  and  no  effort  of  the  will  can  then 
prevent  the  ingress  of  air.3     It  is  easy  to  understand  why,  in  the  higher  animals 
at  least,  and  more  especially  in  Man,  the  respiratory  actions  should  be  thus  placed 
under  the  direction  of  the  will :  since  they  are  subservient  to  the  production  of 
those   Sounds,  by  which  individuals  communicate  their  feelings  and   desires  to 
each  other;  and  which,  when  articulate,  are  capable  of  so  completely  expressing 
what  is  passing  in  the  mind  of  the  speaker.     If  the  respiratory  muscles  of  Man 
were  no  more  under  his  control,  than  they  appear  to  be  in  the  Insect  or  Mollusk, 
he  might  be  provided  with  the  most  perfect  apparatus  of  speech,  and  yet  he 
would  not  be  able  to  employ  it  to  any  advantage. 

303.  The  motor  power  of  the  Respiratory  nerves  is  exercised,  however,  not 

1  Such  cases  are  mentioned  by  Sir  C.  Bell,  in  the  Appendix  to  his  work  on  the  "  Nervous 
System  of  the  Human  Body." 

a  "On  Laryngismus  Stridulus,"  p.  417. 

8  It  is  asserted  by  M.  Bourdon  ("Recherches  sur  le  Me*canisme  de  la  Respiration," 
p.  21),  that  no  person  ever  committed  suicide,  though  many  have  attempted  to  do  so,  by 
simply  holding  the  breath  :  the  control  of  the  will  over  the  respiratory  muscles  not  being 
sufficiently  great  to  antagonize  the  stimulus  of  the  "  besoin  de  respirer,"  when  this  haa 
become  aggravated  by  the  temporary  cessation  of  the  action.  But  such  persons  have  suc- 
ceeded better,  by  holding  the  face  beneath  the  surface  of  water;  because  here  another  set 
of  muscles  is  called  into  action,  which  are  much  more  under  the  control  of  the  will,  than 
are  those  of  respiration ;  and  a  strong  volition  applied  to  these  can  prevent  all  access  of 
air  to  the  lungs,  however  violent  may  be  the  inspiratory  efforts. 


294  OF    RESPIRATION. 

only  on  the  muscles  which  perform  the  inspiratory  and  expiratory  movements, 
but  on  those  which  guard  the  entrance  to  the  wind-pipe,  and  also  on  some  other 
parts.  The  movements  of  the  internal  respiratory  apparatus  are  chiefly,  if  not 
entirely,  effected  through  the  medium  of  the  motor  fibres,  which  the  Pneumo- 
gastric  contains.  These  motor  fibres  exist  in  very  different  proportions  in  its 
different  branches.  For  example,  the  pharyngeal  and  ossophageal  branches,  by 
which  the  muscles  of  deglutition  are  excited  to  contraction  (§§  81,  82),  possess  a 
much  larger  amount  of  them,  and  exhibit  much  less  sensibility  when  irritated, 
than  do  other  divisions  of  the  trunk.  Between  the  superior  and  inferior  laryn- 
geal  nerves,  again,  there  is  an  important  difference,  which  anatomical  and  experi- 
mental research  has  now  very  clearly  demonstrated.  It  has  long  been  known, 
that  section  of  the  Pneumogastrics  in  the  neck,  above  the  inferior  laryngeals,  is 
frequently  followed  by  suffocation,  resulting  from  closure  of  the  glottis  j  and 
hence  it  has  been  inferred,  that  the  office  of  the  inferior  laryngeals  was  to  call 
into  action  the  dilators  of  the  larynx,  whilst  the  superior  laryngeals  were  supposed 
to  stimulate  the  constrictors.  This  view,  however,  is  incorrect.  It  is  inconsistent 
with  the  results  of  anatomical  examination  into  the  respective  distribution  of 
these  two  trunks ;  and  it  has  been  completely  overthrown  by  the  very  careful  and 
satisfactory  observations  and  experiments  of  Dr.  J.  Eeid,1  which  have  established 
that,  whilst  the  inferior  laryngeal  is  the  motor  nerve  of  nearly  all  the  laryngeal 
muscles,  the  superior  laryngeal  is  the  excitor  or  afferent  nerve,  conveying  to  the 
Medulla  Oblongata  the  impressions  by  which  muscular  movements  are  excited. 
The  motor  endowments  of  the  latter  are  limited  to  the  crico-thyroid  muscle,  to 
which  alone  of  all  the  muscles  its  filaments  can  be  traced,  the  remainder  being 
distributed  beneath  the  mucous  surface  of  the  larynx ;  and  its  sensibility  is  very 
evident,  when  it  is  pinched  or  irritated  during  experiments  upon  it.  On  the 
other  hand,  the  motor  character  of  the  inferior  laryngeal  branch  is  shown  by  its 
very  slight  sensibility  to  injury,  by  its  nearly  exclusive  distribution  to  muscles, 
and  by  its  influence  in  exciting  contraction  of  these  when  its  separated  trunk  is 
stimulated. 

304.  It  has  been  ascertained  by  Dr.  J.  Reid  (Op.  cit.),  that,  if  the  inferior 
laryngeal  branches  be  divided,  or  the  trunk  of  the  pneumogastric  be  cut  above 
their  origin  from  it,  there  is  no  constriction  of  the  glottis,  but  a  paralysed  state 
of  its  muscles.  After  the  first  paroxysm  occasioned  by  the  operation,  a  period 
of  quiescence  and  freedom  from  dyspnoea  often  supervenes,  the  respirations  being 
performed  with  ease  so  long  as  the  animal  remains  at  rest ;  but  an  unusual  respi- 
ratory movement, -such  as  takes  place  at  the  commencement  of  a  struggle,  induces 
immediate  symptoms  of  suffocation,  —  the  current  of  air  carrying  inwards  the 
arytenoid  cartilages,  which  are  rendered  passive  by  the  paralysed  state  of  their 
muscles ;  and  these,  falling  upon  the  opening  of  the  glottis,  like  valves,  obstruct 
the  entrance  of  air  into  the  lungs.  The  more  effort  is  made,  the  greater  will  be 
the  obstruction :  and  accordingly,  it  is  generally  necessary  to  counteract  the 
tendency  to  suffocation,  when  it  is  desired  to  prolong  the  life  of  the  animal  after 
this  operation,  by  making  an  opening  into  the  trachea.  Dr.  Reid  further  ascer- 
tained, that  the  application  of  a  stimulus  to  the  inferior  laryngeal  nerves,  when 
separated  from  the  trunk,  would  occasion  distinct  muscular  contractions  in  the 
larynx ;  whilst  a  corresponding  stimulus  applied  to  the  superior  laryngeal  occa- 
sioned no  muscular  movement,  except  in  the  crico-thyroid  muscle.  But  when 
the  superior  laryngeals  were  entire,  irritation  of  the  mucous  surface  of  the  larynx, 
or  of  the  trunks  themselves,  produced  contraction  of  the  glottis  and  efforts  to 
cough)  effects  which  were  at  once  prevented  by  dividing  those  nerves,  and  thereby 
cutting-off  their  communication  with  the  Medulla  Oblongata.  There  can  be  no 
doubt,  then,  that  the  superior  and  inferior  laryngeal  branches  constitute  the  circle 
of  incident  and  motor  nerves,  by  which  the  aperture  of  the  glottis  is  governed, 

1  "Edinb.  Med.  and  Surg.  Journ.,"  Jan.  1838;  and  "  Anat.,  Physiol.  and  Pathol.  Res.,"  • 
chap.  iv. 


OF    THE     RESPIRATORY    MOVEMENTS.  295 

and  by  which  any  irritation  of  the  larynx  is  made  to  close  the  passage,  so  as  to 
prevent  the  entrance  of  improper  substances ;  whilst  the  superior  laryngeal  nerve 
also  excites  the  muscles  of  expiration,  so  as  to  cause  the  violent  ejection  of  a 
blast  of  air,  by  which  the  offending  gas,  fluid,  or  solid,  may  be  carried-oif.  The 
effect  of  carbonic  acid  in  causing  spasmodic  closure  of  the  glottis,  is  well  known ; 
and  affords  a  beautiful  example  of  the  protective  office  of  this  system  of  nerves. 
The  mucous  surface  of  the  trachea  and  bronchi  appears,  from  the  experiments 
of  Valentin,  to  be  endowed  with  excitability,  so  that  stimuli  applied  to  it  produce 
expiratory  movements ;  and  this  evidently  operates  through  the  branches  of  the 
pneumogastric  distributed  upon  the  membrane.  Here,  as  elsewhere,  we  find  that 
a  stimulus  applied  to  the  surface  has  a  much  more  decided  influence,  than  irrita- 
tion of  the  trunk  of  the  nerve  supplying  it. 

305.  The  actions  of  sighing,  yawning,  sobbing,  laughing,  coughing,  and 
sneezing,  are  nothing  else  than  simple  modifications  of  the  ordinary  movements 
of  respiration,  excited  either  by  mental  emotions,  or  by  some  stimulus  originating 
in  the  respiratory  organs  themselves. — Sighing  is  nothing  more  than  a  very  long- 
drawn  inspiration,  in  which  a  larger  quantity  of  air  than  usual  is  made  to  enter 
the  lungs.  This  is  continually  taking  place  to  a  moderate  degree ;  and  we  notice 
it  particularly  when  the  attention  is  released,  after  having  been  fixed  upon  an 
object  which  has  excited  it  strongly,  and  which  has  prevented  our  feeling  the 
insufficiency  of  the  ordinary  movements  of  respiration.  Hence  this  action  is  only 
occasionally  connected  with  mental  emotion. — Yawning  is  a  still  deeper  inspira- 
tion, which  is  accompanied  by  a  kind  of  spasmodic  contraction  of  the  muscles  of 
the  jaw,  and  also  by  a  very  great  elevation  of  the  ribs,  in  which  the  scapulae 
partake.  The  purely  involuntary  character  of  this  movement  is  sometimes  seen, 
in  a  remarkable  manner,  in  cases  of  palsy ;  in  which  the  patient  cannot  raise  his 
shoulder  by  an  effort  of  the  will,  but  does  so  in  the  act  of  yawning.  Neverthe- 
less this  act  may  be  performed  by  the  will,  though  not  completely;  and  it  is  one 
that  is  particularly  excited  by  an  involuntary  tendency  to  imitation,  as  every  one 
must  have  experienced  who  has  ever  been  in  company  with  a  set  of  yawners. — 
Sobbing  is  the  consequence  of  a  series  of  short  convulsive  contractions  of  the 
diaphragm ;  and  it  is  usually  accompanied  by  a  closure  of  the  glottis,  so  that  no 
air  really  enters. — In  Hiccup,  the  same  convulsive  respiratory  movement  occurs, 
and  the  glottis  closes  suddenly  in  the  midst  of  it;  the  sound  is  occasioned  by 
the  impulse  of  the  column  of  air  in  motion  against  the  glottis. — In  Laughing,  a 
precisely  reverse  action  takes  place;  the  muscles  of  expiration  are  in  convulsive 
movement,  more  or  less  violent,  and  send-out  the  breath  in  a  series  of  jerks,  the 
glottis  being  open.  This  sometimes  goes-on,  until  the  diaphragm  is  more  arched, 
and  the  chest  is  more  completely  emptied  of  air,  than  it  could  be  by  an  ordinary 
movement  of  expiration. — The  act  of  Crying,  though  occasioned  by  a  contrary 
emotion,  is,  so  far  as  the  respiration  is  concerned,  very  nearly  the  same  as  the 
last.  Every  one  knows  the  effect  of  mixed  emotions,  in  producing  an  expression 
of  them  which  is  "between  a  laugh  and  a  cry/'  — The  greater  part  of  the  pre- 
ceding movements  seem  to  belong  as  much  to  the  consensual  or  to  the  emotional, 
as  to  the  excito-motor  group  of  actions  (§  45) ;  for  whilst  they  are  sometimes  the 
result  of  peculiar  states  of  the  respiratory  organs,  or  of  the  bodily  system  in 
general,  they  may  also  be  called-forth  by  influences  which  operate  directly  through 
the  senses,  or  which  excite  the  emotions.  Thus,  whilst  Sighing  and  Yawning 
often  occur  as  simple  results  of  deficient  aeration,  they  may  be  brought-on, — tho 
former  by  a  depressed  state  of  the  feelings, — the  latter  by  the  mere  sight  of  the 
act  in  another  person.  The  actions  of  Laughter  and  Crying  seem  never  to 
originate  in  the  respiratory  system ;  but  to  be  always  either  expressions  of  the 
emotions,  or  simple  results  of  sensations, — as  when  crying  arises  from  the  sense 
of  pain, — and  laughter  from  that  of  tickling.  The  origin  of  the  act  of  Hiccup 
does  not  seem  very  clear;  but  the  movement  is  probably  of  a  purely-reflex 
nature. 


296  OF    KESPIRATION. 

306.  The  purposes   of  the  acts  of  Coughing  and   Sneezing  are,  in  both  in- 
stances, to  expel  substances  from  the  air-passages,  which  are  sources  of  irritation 
there ;  and  this  is  accomplished  in  both,  by  a  violent  expiratory  effort,  which 
sends-forth  a  blast  of  air  from  the  lungs. —  Coughing  occurs,  when  the  source  of 
irritation  is  situated  at  the  back  of  the  mouth,  in  the  trachea  or  bronchial  tubes. 
The  irritation  may  be  produced  by  acrid  vapours,  or  by  liquids  or  solids,  that 
have  found   their  way  into  these  passages  ;  or  by  secretions  which  have  been 
poured  into  them  in  unusual  quantity,  as  the  result  of  disease  ;  or  by  the  simple 
entrance  of  air  (especially  if  cold),  when  the  membrane  is  in  a  peculiarly  irri- 
table state.      Any  of  these  causes  may  produce  an  impression  upon  the  excitor 
fibres  of  the  Pneumogastrics,  which,  being  conveyed  to  the  Medulla  Oblongata, 
gives-rise  to  the  transmission  of  a  motor  impulse  to   the   several  muscles,  that 
combines  them  in  the  act  of  coughing.     This  act  consists, — 1st,  in  a  long  inspi- 
ration, which  fills  the  lungs;  2nd,  in  the  closure  of  the  glottis  at  the  moment 
when  expiration  commences;  and  3rd,  in  the  bursting  open  (as  it  were)  of  the 
glottis,  by  the  violence  of  the  expiratory  movement ;  so  that  a  sudden  blast  of 
air  is  forced  up  the  air-passages,  carrying  before  it  anything  that  may  offer  an 
obstruction. — The  difference  between  Coughing  and  Sneezing  consists  in  this, — 
that  in  the  latter,  the  communication  between  the  larynx  and  the  mouth  is  partly 
or  entirely  closed  by  the  drawing-together  of  the  sides  of  the  velum  palati  over 
the  back  of  the  tongue ;  so  that  the  blast  of  air  is  directed,  more  or  less  com- 
pletely, through  the  nose,  in  such  a  way  as  to  carry-off  any  source  of  irritation 
that  may  be  present  there. — It  is  difficult  to  say  how  far  these  actions  are  inde- 
pendent of  consciousness,  or  how  far  they  may  require  the  stimulus  of  sensation 
for  their  performance. 

307.  Various  alterations  are  produced  in  the  Lungs,  by  section  of  the  Pneu- 
mogastric  nerves;  and  it  has  been  supposed  that  these  exert  some  more  imme- 
diate and  direct  influence  over  the  condition  of  those  organs,  than  their  connec- 
tion with  the  respiratory  movements  will  serve  to  account-for.     The  inquiry  into 
the  nature  and  succession  of  these  changes  has  been  most  carefully  prosecuted  by 
Dr.  J.  Reid  (Op.  cit.);  and  as  his  results  have  a  very  important  bearing  on  seve- 
ral physiological  and  pathological  questions  of  great  interest,  a  summary  of  them 
will  be  here  given. — In  the  first  place,  it  has  been  fully  established  by  Dr.  Reid, 
that  section  of  the  Vagus  on  one  side  only  does  not  necessarily,  or  even  gene- 
rally, induce  disease  of  the  lung;  and  hence  the  important  inference  may  be 
drawn,  that  the  nerve  does  not  exercise  any  immediate  influence  on  its  functions. 
When  both  Vagi  are  divided,  however,  the  animal  rarely  survives  long;  but  its 
death  frequently  results  from  the  disorder  of  the  digestive  functions.     Neverthe- 
less, the  power  of  digestion  is  sometimes  restored  sufficiently  to  re-invigorate  the 
animals ;  and  their  lives  may  then  be  prolonged  for  a  considerable  time  (§  102). 
In  fifteen  out  of  seventeen  animals  experimented-on  by  Dr.  Reid,  the  lungs  were 
found  more  or  less  unfit  for  the  healthy  performance  of  their  functions.     The 
most  common  morbid  changes  were  a  congested  state  of  the  blood-vessels,  and 
an  effusion  of  frothy  serum  into  the  air-cells  and  bronchial-tubes.     In  eight  out 
of  the  fifteen,  these  changes  were  strongly  marked.     In  some  portions  of  the 
lungs,  the  quantity  of  blood  was  so  great  as  to  render  them  dense.     The  degree 
of  congestion  varied  in  different  parts  of  the  same  lung ;  but  it  was  generally 
greatest  at  the  most  depending  portions.     The  condensation  was  generally  greater 
than  could  be  accounted-for  by  the  mere  congestion  of  blood  in  the  vessels,  and 
probably  arose  from  the  escape  of  the  solid  parts  of  the  blood  into  the  tissue  of 
the  lung.     In  some  instances  the  condensation  was  so  great,  that  considerable 
portions  of  the  lung  sank  in  water,  and  did  not  crepitate ;  but  they  did  not  pre- 
sent the  granulated  appearance  of  the  second  stage  of  ordinary  pneumonia.     In 
five  cases  in  which  the  animal  had  survived  a  considerable  time,  portions  of  the 
lungs  exhibited  the  second,  and  even  the  third  stages  of  pneumonia,  with  puri- 
forni  effusion  into  the  small  bronchial  tubes;  and  in  two,  gangrene  had  super- 


OF    THE    KESPIRATORY    MOVEMENTS.  297 

vened. — One  of  the  most  important  points  to  ascertain  in  an  investigation  of  this 
kind,  is  the  first  departure  from  a  healthy  state;  to  decide  whether  the  effusion 
of  frothy  reddish  serum,  hy  interfering  with  the  usual  change  in  the  lungs, 
causes  the  congested  state  of  the  pulmonary  vessels,  and  the  laboured  respira- 
tion ;  or  whether  the  effusion  is  the  effect  of  a  previously-congested  state  of  the 
blood-vessels.  The  former  is  the  opinion  of  many  physiologists,  who  have  re- 
presented the  effusion  of  serum  as  a  process  of  morbid  secretion,  directly  result- 
ing from  the  disorder  of  that  function  produced  by  the  section  of  the  nerve;  the 
latter  appears  the  unavoidable  inference  from  the  carefully-noted  results  of  Dr. 
Reid's  experiments.  In  several  of  these,  only  a  very  small  quantity  of  frothy 
scrum  was  found  in  the  air-tubes,  even  when  the  lungs  were  found  loaded  with 
blood,  and  when  the  respiration  before  death,  was  very  laboured.  This  naturally 
leads  us  to  doubt,  whether  the  frothy  serum  is  the  cause  of  the  laboured  respira- 
tion, and  of  the  congested  state  of  the  pulmonary  vessels,  in  those  cases  where  it 
is  present;  though  there  can  be  no  doubt  that,  when  once  it  is  effused,  it  must 
powerfully  tend  to  increase  the  difficulty  of  respiration,  and  still  further  to  im- 
pede the  circulation  through  the  lungs.  Dr.  R.  has  satisfied  himself  of  an  im- 
portant point  which  has  been  overlooked  by  others,  namely,  that  this  frothy  fluid 
is  not  mucus,  though  occasionally  mixed  with  it,  but  that  it  is  the  frothy  serum 
so  frequently  found  in  cases  where  the  circulation  through  the  lungs  has  been 
impeded  before  death.  From  this  and  other  facts,  Dr.  II.  concludes  "that  the 
congestion  of  the  blood-vessels  is  the  first  departure  from  the  healthy  state  of  the 
lung,  and  that  the  effusion  of  frothy  serum  is  a  subsequent  effect." 

308.  The  next  point,  therefore,  to  be  inquired-into,  is  the  cause  of  this  con- 
gestion ;  and  this  is  most  satisfactorily  explained,  in  accordance  with  the  general 
laws  of  the  Circulation  (§  275),  by  remembering  that  section  of  the  Pneumogas- 
trics  greatly  diminishes  the  frequency  of  the  respiratory  movements,  and  that  the 
quantity  of  air  introduced  into  the  lungs  is,  therefore,  very  insufficient  for  the 
due  aeration  of  the  blood.  There  is  now  abundant  evidence,  in  regard  to  the 
Pulmonary  circulation  in  particular,  that  to  prevent  the  admission  of  oxygen  into 
the  lungs,  either  by  causing  the  animal  to  breathe  pure  nitrogen  or  hydrogen,  or 
by  occlusion  of  the  air-passages,  is  to  bring  the  circulation  through  their  capil- 
laries to  a  speedy  check  (§  327).  Hence  we  should  at  once  be  led  to  infer,  that 
diminution  in  the  number  of  Respiratory  movements  would  produce  the  same 
effect ;  and  as  little  or  no  difference  in  their  frequency  is  produced  by  section  of 
one  Vagus  only,  the  usual  absence  of  morbid  changes  in  the  lungs  supplied  by 
it  is  fully  explained.  The  congestion  of  the  vessels  induced  by  insufficient  aera- 
tion, satisfactorily  accounts  not  only  for  the  effusion  of  serum,  but  also  for  the 
tendency  to  pass  into  the  inflammatory  condition,  sometimes  presented  by  the 
lungs,  as  by  other  organs  similarly  affected.  Dr.  Reid  confirms  this  view,  by  the 
particulars  of  cases  of  disease  in  the  human  subject,  in  which  the  lungs  presented 
after  death  a  condition  similar  to  that  observed  in  the  lower  animals  after  section 
of  the  Vagi;  and  in  these  individuals,  the  respiratory  movements  had  been 
much  less  frequent  than  natural  during  the  latter  part  of  life,  owing  to  a  torpid 
condition  of  the  nervous  centres.  The  opinion  (held  especially  by  Dr.  Wilson 
Philip)  that  section  of  the  Par  Vagum  produces  the  serous  effusion,  by  its  direct 
influence  on  the  function  of  Secretion,  is  further  invalidated  by  the  fact  stated 
by  Dr.  Reid,  that  he  always  found  the  bronchial  membrane  covered  with  its  true 
mucus,  except  when  inflammation  was  present.  —  "  The  experimental  history  of 
the  Par  Vagum,"  it  is  justly  remarked  by  Dr.  Reid,  "furnishes  an  excellent  il- 
lustration of  the  numerous  difficulties  with  which  the  physiologist  has  to  contend, 
from  the  impossibility  of  insulating  any  individual  organ  from  its  mutual  actions 
and  reactions,  when  he  wishes  to  examine  the  order  and  dependence  of  its  phe- 
nomena." In  such  investigations,  no  useful  inference  can  be  drawn  from  one  or 
two  experiments  only;  in  order  to  avoid  all  sources  of  fallacy,  a  large  number 
must  be  made ;  the  points  in  which  all  agree,  must  be  separated  from  others  in 


298 


OF    KESPI RATION. 


which  there  is  a  variation  of  results;  and  it  must  be  then  inquired,  to  what  the 
latter  is  due.1 

2.   Effects  of  Respiration  on  the  Air. 

309.  The  total  amount  of  air  which  can  be  drawn  into  the  Lungs  by  the 
deepest  possible  inspiratory  movement,  by  no  means  affords  a  measure  of  the 
quantity  which  they  ordinarily  contain.  It  is  in  fact  composed,  as  was  first 
pointed-out  by  Mr.  Julius  Jeffreys,2  of  several  different  quantities,  which  may  be 
distinguished  as  follows  : — 

1.  Residual  Air  ;  that  which  cannot  be  displaced  by  the  most  powerful  expi- 
ration, which  always  remains  in  the  thorax  so  long  as  the  lungs  retain  their  natu- 
ral structure,  and  over  which,  therefore,  we  have  no  control. 

2.  Supplemental  Air ;  that  portion  which  remains  in  the  chest  after  the  ordi- 
nary gentle  expiration,  but  which  may  be  displaced  at  will. 

3.  Breathing  or  Tidal  Air ;  that  volume  which  is  displaced  by  the  constant 
gentle  inspiration  and  expiration. 

4.  Cvmplemental  Air ;  the  quantity  which  can  be  inhaled  by  the  deepest 
possible   inspiration,   over   and    above   that  which   is   introduced   in    ordinary 
breathing. 

The  amount  which  can  be  expelled  by  the  most  forcible  expiration  after  the 
fullest  inspiration,  and  which  is  consequently  the  sum  of  the  2nd,  3rd,  and  4th 
of  these  quantities,  is  designated  by  Dr.  Hutchinson3  as  the  Vital  Capacity, 
being  that  volume  of  air  which  can  be  displaced  by  living  movements.  This 
'  vital  capacity '  is  less  dependent  than  might  have  been  supposed,  upon  the  abso- 
lute dimensions  of  the  thoracic  cavity,  being  yet  more  influenced  by  its  mobility. 
Thus  of  two  sets  of  men  of  the  same  height,  one  measuring  35  inches  round  the 
chest,  and  the  other  38  inches,  the  average  vital  capacity  of  the  first  was  found 
to  be  235  inches,  and  that  of  the  second  only  226  inches;  for  notwithstanding 
the  greater  absolute  capacity  indicated  by  the  larger  circumference  of  the  latter, 
the  inferior  mobility  of  the  chest  caused  more  '  residual  air '  to  remain  behind 
after  the  deepest  expiration.  By  taking  the  average  of  nearly  5000  observations, 
Dr.  Hutchinson  has  arrived  at  the  very  remarkable  conclusion  (Op.  cit.,  p.  1072), 
that  of  all  the  elements  whose  variation  might  be  supposed  to  affect  the  '  vital 
capacity/  Height  alone  seems  to  have  any  constant  relation  to  it;  and  that  this 
relation  is  capable  of  being  expressed  in  a  simple  numerical  form.  The  follow- 
ing table  represents  the  'vital  capacity'  regarded  by  Dr.  H.  as  necessary  to  health 
at  the  middle  period  of  life,  in  the  Male  sex,  for  each  inch  of  height  between 
five  and  six  feet : — 


5ft. 
5 

5 
5 
5 
5 
5 
5 
5 
5 
5 
5 


Height. 

0  in.  to  5  ft. 


Vital  Capacity. 
1  in 174  cubic  in. 


1 

5 

2  • 

182 

2 

5 

3  ' 

190 

8 

5 

4  ' 

198 

4 

5 

5  ' 

206 

5 

5 

6  ' 

214 

6 

5 

7  ' 

222 

7 

5 

8  ' 

230 

8 

5 

9  « 

238 

9 

5 

10  " 

246 

10 

5 

11  ' 

254 

11 

6 

0  < 

262 

1  On  the  important  subject  of  the  Mechanism  of  Respiration,  the  following  Memoirs  may 
be  consulted  in  addition  to  those  already  referred-to  : — Dr.  J.  Reid's  Art.  'Respiration  '  in 
"Cyclop,  of  Anat.  and  Physiol.,"  vol.  iv. :  Dr.  Hutchinson  in  "  Med.-Chir.  Trans.,"  vol. 
xxix;  Dr.  Sibson  in  "Phil.  Trans.,"  1846,  "  Med.  Gaz.,"  vol.  xli.,  "Med.-Chir.  Trans.," 
vol.  xxxi.,  and  "Trans,  of  Prov.  Med.  Assoc.,"  1850;  Beau  and  Maissiat  in  "Archiv. 
Gen.,"  1842:  Mendelssohn  "  Der  Mechanismus  der  Respiration  und  Circulation,"  Berlin, 
J845;  and  Vierordt,  Art.  'Respiration'  in  "Wagner's  Handworterbuch  der  Physiologie," 
hand.  ii. 

a  "  Statics  of  the  Human  Chest,"  1843. 

*  "Cyclop,  of  Aiiat.  and  Physiol.,"  vol.  iv,,  Art.  'Thorax.' 


EFFECTS    OF    RESPIRATION    ON    THE    AIR.  299 

This  relation  may  be  briefly  expressed  by  the  rule,  that  for  every  inch  of  stature, 
from  Jive  to  six  feet,  eight  additional  cubic  inches  of  air  (at  60°  Fahr.)  are 
given-out  by  a  forced  expiration  after  a  full  inspiration.  — There  is  also  a  rela- 
tion between  '  vital  capacity '  and  Weight ;  but  of  a  different  kind  from  that 
which  might  have  been  anticipated.  So  far  as  the  increase  in  weight  is  simply 
proportional  to  the  increase  in  height,  the  relation  is  of  course  the  same  for  the 
one  as  for  the  other.  But  if  the  excess  of  weight  should  depend  upon  corpu- 
lence, the  vital  capacity  decreases  in  a  very  marked  manner,  being  always  very 
low  in  corpulent  men.  The  general  result  of  Dr.  Hutchinson's  observations  on 
this  point,  is  expressed  by  him  as  follows  :  When  the  man  exceeds  the  average 
weight  (at  each  height)  by  7  per  cent.,  the  vital  capacity  decreases  1  cub.  in.  per 
Ib.  for  the  next  35  Ibs.  above  this  weight. — The  influence  of  Age  upon  the  '  vital 
capacity '  is  less  marked  than  might  have  been  anticipated.  The  general  fact 
seems  to  be,  that  the  'vital  capacity'  undergoes  a  slight  increase  between  15  and 
35  years,  and  then  gradually  decreases,  the  decline  being  more  rapid  than  the 
augmentation,  so  that  by  the  age  of  66  it  has  diminished  to  about  4-5ths  of  the 
maximum.  —  There  does  not  seem  to  be  as  close  a  relation  between  the  '  vital 
capacity'  and  Muscular  Vigour,  as  might  d  priori  have  been  expected,  and  as  an 
attempt  has  been  made  to  establish.1  Cases  are  not  unfrequent,  in  which  men 
of  athletic  constitution  have  an  absolute  deficiency,  whilst  others  by  no  means 
remarkable  for  physical  power  present  a  large  excess.2  In  fact,  as  Dr.  C.  R. 
Hall  has  justly  remarked,  this  measure  indicates,  not  what  a  person  does  breathe, 
bat  what  he  can  breathe. — The  maximum  'vital  capacity'  met-with  by  Dr.  Hut- 
chinson  in  his  entire  series  of  observations,  was  464  cub.  in. ;  this  was  in  a  man 
7  feet  high,  whose  weight  was  308  Ibs.  The  minimum  was  not  more  than  46 
cub.  in. ;  this  was  in  a  dwarf  (Don  Francisco),  whose  height  was  only  29  inches, 
and  weight  40  Ibs. 

310.  But  however  constant  the  above  averages  may  prove  to  be,  when  tested 
by  a  still  larger  number  of  observations,  it  yet  remains  to  be  determined  within 
what  limits  individual  variation  may  range,  without  departure  from  the  standard 
of  health.     It  is  considered  by  Dr.  Hutchinson  (Op.  cit.,  p.  1079)  that  a  de- 
ficiency of  16  per  cent,  (unless  the  individual  should  be  very  corpulent)  should 
excite  suspicion  of  disease;  but  the  observations  of  Dr.  C.  R.  Hall  (loc.  cit.) 
seem  to  show  that  the  range  is  considerably  wider,  especially  in  females.     They 
also  indicate  that  even  a  marked  deficiency  in  vital  capacity  must  not  be  regarded 
as  indicative  of  pulmonary  disease ;  for  it  may  be  dependent  upon  disorder  of 
the  abdominal  viscera,  especially  upon  congested  liver. 

311.  In  estimating,  however,  the  effects  of  the  Respiratory  function  upon  the 
Air  which  passes  through  the  lungs,  we  are  not  so  much  concerned  with  the 
quantity  which  may  be  drawn-in  and  forced-out,  as  with  that  actually  exchanged 
at  each  movement.     There  are  many  difficulties  in  arriving  at  any  exact  conclu- 
sion upon  this  point ;  and  hence  it  happens  that  the  estimates  of  those  who  have 
inquired   into  it  are    singularly  discrepant.     The   following   are   the   amounta 
assigned  by  some  of  the  most  recent  experimenters : 

Herbst3 20—30  cubic  inches. 

Valentin4 14—92 

Vierordt ' 10—42 

Coathupe6 16 


Hutchinson 


average 16—20 

extremes 7 — 77 


See  Dr.  Jackson  in  "Philadelphia  Medical  Examiner,"  1851,  p.  51. 

See  Dr.  C.  Radclyffe  Hall  in  "  Trans,  of  Prov.  Med.  and  Surg.  Assoc.,"  1851. 

"  Meckel's  Archiv.,"  1828.  *  "  Lehrbuch  der  Physiologic,"  band  i.  p.  538. 

"Wagner's  Handworterbuch,"  band  ii.  p.  835. 

"  Philosophical  Magazine,"  1839,  vol.  xiv.  p.  401. 

"Cyclop,  of  Anat.  and  Phys.,"  vol.  iv.  p.  1067. 


300  OF    RESPIRATION. 

If  we  take  20  cubic  inches  as  the  average  quantity  exchanged  at  each  respira- 
tion, we  cannot  but  observe  how  small  a  proportion  it  bears  to  the  entire  amount 
which  the  lungs  usually  contain ;  for  the  '  residual  air/  which  cannot  be  ex- 
pelled, is  estimated  by  Dr.  Hutchinson  at  from  75  to  100  cubic  inches,  and  the 
'  supplemental  air/  which  can  only  be  expelled  by  a  forced  expiration,  is  about  as 
much  more;  the  sum  of  the  two  being  from  150  to  200  cub.  in.,  or  from  7£  to 
10  times  the  l  breathing  volume/  Now  it  is  obvious  that  if  no  provision  existed, 
for  mingling  the  air  inspired  with  the  air  already  occupying  the  lungs,  the  former 
would  penetrate  no  further  than  the  larger  air-passages ;  and  as  this  would  be 
again  thrown-out  at  the  next  expiration,  the  bulk  of  the  air  contained  in  the 
lungs  would  remain  altogether  without  renewal,  and  the  expired  air  would  not 
be  found  to  have  undergone  any  change.1  That  a  change  is  effected,  however,  in 
the  whole  volume  of  the  air  contained  in  the  lungs,  with  every  inspiration,  is 
indicated  by  the  difference  between  the  inspired  and  expired  air ;  and  this  change 
must  be  attributed  to  the  l  mutual  diffusion '  of  gases,  these  tending  to  interpene- 
trate one  another,  when  either  of  different  densities  or  of  different  temperatures, 
according  to  the  law  discovered  by  Prof.  Graham  (§  314). 

[Prof.  Draper,  of  New  York,  has  recently  performed  some  experiments  to 
determine  whether  gaseous  diffusion  takes  place  with  sufficient  velocity  to  meet 
the  conditions  of  the  function  of  respiration.  It  has  usually  been  taken  for 
granted,  that  diffusion  takes  place  with  great  rapidity,  and  it  has  even  been  sup- 
posed that  "  a  small  quantity  of  carbonic  acid  would  diffuse  itself  through  a  large 
volume  of  atmospheric  air  with  the  same  rapidity  that  it  would  dilate  into  a 
vacuum  of  the  same  dimensions,"  this  he  has  shown  to  be  altogether  a  misconcep- 
tion. The  experiments  alluded  to,  go  to  show  "that  the  diffusion  of  carbonic 
acid  into  air  even  when  there  is  no  obstruction,  and  the  distance  to  be  traversed 
only  a  few  inches,  occupies  quite  a  considerable  period  of  time — a  period  which, 
of  course,  is  increased,  if  there  be  any  obstruction  or  resistance  in  the  way,  and 
which  must,  therefore,  be  very  greatly  prolonged  when  the  diffusion  has  to  be 
made  through  slender,  long,  and  winding  passages/' 

In  order  to  explain  completely  the  introduction  of  atmospheric  air  and  the , 
changes  in  the  contents  of  the  air-vesicles,  Prof.  Draper  calls  attention  to  the 
well-known  agency  of  the  organic  muscular  fibres  of  the  bronchial  tubes,  which 
are  believed  to  possess  the  power  of  varying  the  capacity  of  the  tube.  With 
this  agency  he  explains  the  respiratory  act  as  follows :  The  carbonic  acid,  vapour 
of  water,  and  excess  of  nitrogen,  if  any,  which  have  accumulated  in  the.  pul- 
monary vesicles  belonging  to  any  given  bronchial  tree,  are  expelled  therefrom  by 
the  muscular  contraction  of  the  circular  organic  fibres,  and  are  delivered  into  the 
larger  bronchial  tubes,  in  which  diffusion  at  once  takes  place  with  the  air  just 
introduced.  As  soon  as  the  expulsion  is  perfect,  relaxation  of  the  muscular 
fibres  occurs,  and  the  passages  and  cells  dilating  both  through  their  own  elasticity 
and  the  exhaustive  effect  arising  from  the  simultaneous  contraction  of  other  bron- 
chial trees,  fresh  air  is  drawn  into  them ;  the  alternate  expulsion  and  introduc- 
tion being  accomplished  by  muscular  contraction  and  elasticity. 

Dr.  Draper  supposes  that  different  bronchial  trees  submit  to  this  action  at  suc- 
cessive periods  of  time,  some  being  contracting  whilst  others  are  dilating. 

In  thus  presenting  the  organic  muscular  fibres  as  the  chief  agent  for  the  intro- 
duction of  air  to  the  blood,  we  raise  them  from  the  doubtful  position  they  have 
hitherto  occupied  in  the  estimation  of  physiological  writers.  "  It  is  not  known 
under  what  circumstances  the  contractile  power  which  the  bronchial  tubes  and, 
perhaps,  the  air-cells  possess,  by  means  of  their  organic  muscular  fibres,  is 
brought  into  action.  It  is  possible  it  may  assist  in  expiration,  but  there  is  no 
evidence  of  its  doing  so."2  From  the  foregoing  experiments,  it  appears  that 

1  See  Mr.  Jeffreys's  "  Statics  of  the  Human  Chest,"  in  which  this  important  point  first 
received  due  consideration. 

12  Kirkes  and  Paget's  Physiol.  Am.  Ed.,  p.  131.  [It  maybe  explained,  as  in  the  case  of 
the  heart,  by  the  influence  excited  by  Carbonic  acid  upon  muscular  fibre,  $  243,  note. — ED.] 


EFFECTS  OF  RESPIRATION  ON  THE  AIR.      301 

the  function  of  respiration  cannot  be  explained  without  appealing  to  their 
agency. 

The  muscular  action  here  contemplated  produces  a  movement  affecting  the 
expulsion  of  foul  air,  analogous  to  the  motion  of  food  along  the  oasophagus,  or 
of  digested  material  along  the  intestines.  In  all  these  cases,  the  mechanical  ope- 
ration is  the  same.  It  is  interesting  to  remark  that  in  all  instances  the  lungs  are 
developed  from  some  portion  of  the  alimentary  canal.  In  man,  they  appear  as 
diverticula  from  the  oesophagus,  and,  in  much  lower  animals,  from  other  parts  of 
that  canal.  Thus,  "  in  the  Holothuriada,  a  membranous  sac  commencing  near 
the  cloaca  and  extending  to  the  mouth,  which,  in  the  higher  forms,  is  double, 
ramifies  into  respiratory  trees,  from  which  the  expulsion  of  the  water  which  has 
been  breathed  is  effected  by  the  contraction  of  the  circular  muscular  fibres  periodi- 
cally. In  the  Bryozoa,  the  pharynx  is  dilated  with  the  water,  which,  after  aera- 
tion has  taken  place,  is  expelled.  In  the  Tunicata,  the  pharynx,  under  the 
designation  of  the  bronchial  sac,  becomes  the  special  respiratory  organ.  In  the 
Ascidians,  the  bronchial  sac  is  emptied  by  the  sudden  contraction  of  its  muscular 
walls.  In  the  Salpians,  the  respiratory  current  is  maintained  by  rhythmical  con- 
tractions and  relaxations  of  the  muscular  sac.  In  the  Cephalopodous  Mollusks, 
the  current  is  sustained  entirely  by  the  muscular  movements  of  the  respiratory 
cavity." ' 

Concurring  with  muscular  action  is  another  force  already  recognized  by  many 
physiologists  as  taking  part  in  the  result.  This  is  the  motion  of  the  vibratile 
cilia,  which  are  found  on  the  mucous  lining  of  the  bronchial  tubes.  In  the 
lower  orders,  ciliary  action  is  usually  resorted  to  for  ensuring  a  presentation  of 
fresh  portions  of  fluid  to  the  respiratory  surface. 

The  air  introduced  by  atmospheric  pressure,  brought  into  play  by  the  action 
of  the  diaphragm  and  other  respiratory  muscles,  fills,  in  ordinary  respiration,  the 
nasal  passages,  trachea,  and  larger  ramifications  of  the  bronchial  tubes.  Between 
it  and  the  gas  coming  from  the  pulmonary  vesicles,  diffusion  steadily  takes  place, 
tending  to  remove  the  cell-gas  into  the  atmosphere ;  but  this  gas  is  not  brought 
from  the  vesicles  by  diffusion,  which  could  not  act  with  sufficient  speed,  but  by 
the  contraction  of  the  circular  organic  muscles  of  the  bronchial  tubelets  and  of 
the  cells,  the  different  bronchial  trees  not  acting  simultaneously,  but  successively. 
As  soon  as  the  contraction  is  over,  the  tubes  expand  by  their  elasticity,  and  air 
is  drawn  into  the  cells.  It  is  probable  that,  in  producing  these  results,  the  vibra- 
tile cilia  conspire,  and  the  effect  is  aided  by  the  contemporaneous  contraction  of 
other  bronchial  trees,  and  the  whole  process  ends  with  the  expulsion  of  the  foul 
air,  which  has  accumulated  in  the  larger  bronchi  and  trachea  by  the  diminution 
which  ensues  in  the  general  capacity  of  the  chest  during  expiration.  In  respi- 
ration, the  lungs  are  not,  therefore,  passive,  as  is  commonly  said.2 — ED.] 

312.  The  total  amount  of  Air  which  passes  through  the  Lungs  in  twenty-four 
hours,  will  of  course  vary  with  the  extent  and  frequency  of  the  respiratory  move- 
ments; and  these  are  liable  to  be  affected  by  many  circumstances,  but  particu- 
larly by  the  relative  degrees  of  repose  and  of  exertion.  Moreover,  as  any  such 
computation  must  be  based  upon  the  datum  of  the  ordinary  volume  of  breathing 
or  '  tidal '  air,  it  is  obvious  that  the  estimates  of  different  observers  must  vary 
with  the  amount  they  adopt.  Thus  Mr.  Coathupe's  estimate  of  the  diurnal  total 
is  460,800  cub.  in.,  or  366^  cubic  feet;  that  of  Vierordt,  from  Ms  observations 
on  his  own  person  in  a  state  of  rest,  is  530,026  cub.  in.,  or  3C('f  cub.  feet,  but 
this,  when  corrected  (by  Scharling's  experiments)  for  a  moderate  amount  of  exer- 
tion, would  be  raised  to  624,087  cub.  in.,  or  361  cub.  feet;  and  that  of  Valentin 
is  as  high  as  688,348  cub.  in.,  or  398£  cub.  feet.  —  It  is  of  great  practical  im- 
portance to  determine  the  quantity  of  air  which  ought  to  be  allowed  for  consump- 
tion by  individuals  confined  in  prisons,  workhouses,  schools,  &c. ;  and  for  this, 

1  Carpenter,  General  and  Comp.  Physiol.,  1854,  Am.  Ed. 

8  The  reader  is  referred  to  the  entire  paper  of  Dr.  Draper,  in  Amer.  Jour.  Med.  Sciences, 
for  April.  1852. 


302  OF    RESPIRATION. 

experience  seems  to  bave  fixed  800  cubic  feet  as  the  minimum  that  can  be  safely 
assigned,  except  where  extraordinary  provisions  are  in  operation  for  its  constant 
renewal  by  ventilation.  The  evil  consequences  of  an  insufficient  supply  of  air 
will  be  noticed  hereafter  (Sect.  3). 

313.  The  alterations  in  this  Air  which  are  effected  by  Respiration,  mainly 
consist  in  the  removal  of  a  portion  of  its  oxygen,  and  the  substitution  of  a  quan- 
tity of  carbonic  acid,  usually  rather  less  in  bulk  than  the  oxygen  which  has 
disappeared.     The  proportion  of  the  air  thus  changed,  appears  to  vary  according 
to  the  frequency  of  the  respirations.     Thus  Vierordt1  found  that,  if  he  only 
respired  six  times  in  a  minute,  the  quantity  of  Carbonic  acid  was  55  per  cent, 
of  the  whole  air  exhaled;  with  twelve  respirations,  it  was  4'2 ;  with  twenty-four, 
it  was  33 ;  with  forty-eight,  it  was  3-0;  and  with  ninety-six,  it  was  2-6  per  cent. 
In  some  of  the  experiments  of  Messrs.  Allen  and  Pef>ys,  it  was  as  much  as  8 
per  cent.     Probably  about  4-35  per  cent,  may  be  taken  as  the  average,  at  the 
ordinary  rate  of  respiration.  —  It  appears,  however,  from  the  researches  of  the 
last-named  experimenters,  that,  if  the  air  be  already  charged  in  some  degree  with 
Carbonic  acid,  the  quantity  exhaled  is  much  less;  for,  when  300  cubic  inches  of 
air  were  respired  for  three  minutes,  only  28£  cubic  inches  (9j  per  cent.)  of  car- 
bonic acid  were  found  in  it;  although  the  previous  rate  of  its  production,  when 
fresh  air  was  taken-in  at  every  respiration,  was  32   cubic  inches  in   a  minute. 
Knowing,  then,  the  necessity  of  a  free  excretion  of  carbonic  acid,  we  are  led  by 
this  fact  to  perceive  the  high  importance  of  ventilation;  for  it  is  not  sufficient 
for  health,  that  a  room  should  contain  the  quantity  of  air  requisite  for  the  sup- 
port of  its  inhalations  during  a  given  time ;  since  after  they  have  remained  in  it 
but  a  part  of  that  time,  the  quantity  of  carbonic  acid  which  its  atmosphere  will 
contain,  will  be  large  enough  to  interfere  greatly  with  the  due  aeration  of  their 
blood,  and  will  thus  cause  oppression  of  the  brain,  and  the  other  morbid  affec- 
tions that  result  from  the  accumulation  of  carbonic  acid  in  the  circulating  fluid. 
— It  appears  from  the  experiments  of  Dr.  Snow,  that  the  presence  of  Carbonic 
acid  in  the  atmosphere  acts  more  deleteriously  upon  the  system,  in  proportion  as 
the  normal  quantity  of  Oxygen  has  been  reduced.     He  found  that  birds  and 
mammalia,  introduced  into  an  atmosphere  containing  only  from  10£  to  16  per 
cent,  of  oxygen,  soon  died,  although  means  were  taken  to  remove  the  carbonic 
acid  set-free  by  their  respiration,  as  fast  as  it  was  formed ;  whilst,  on  the  other 
hand,  an  increase  in  the  proportion  of  carbonic  acid  to  12  or  even  20  per  cent. — 
the  per-centage  of  oxygen  being  kept  to  its  regular  standard  of  21  per  cent. — 
did  not  appear  to  enfeeble  the  vital  actions  more  rapidly,  than  did  the  reduction 
of  the  oxygen  in  the  experiments  just  referred-to.     Dr.  Snow  concludes,  from 
his  experiments  on  the  lower  animals,  that  5  or  6  per  cent,  of  carbonic  acid  can- 
not exist  in  an  atmosphere  respired  by  Man,  without  danger  to  life ;  and  that  less 
than  half  this  amount  will  soon  be  fatal,  when  it  is  formed  at  the  expense  of  the 
oxygen  of  the  air.2 

314.  The  reaction  which  thus  takes  place  between  the  Air  and  the  Blood,  is 
partly  explicable  upon  physical  principles.     It  has  been  shown  by  Prof.  Graham, 
that  when  two  gases,  of  different  specific  gravities,  but  not  disposed  to  unite 
chemically,  are  separated  by  a  porous  septum,  each  will  tend  to  diffuse  itself 
through  the  other;  the  amount  of  each  that  will  traverse  the  septum  (or  its 
1  diffusion  volume'),  being  to  that  of  the  other,  inversely  as  the  square-roots  of 
their  respective  specific  gravities.     According  to  this  law,  the  volume  of  Oxygen 
that  is  taken-in,  should  exceed  that  of  the  Carbonic  acid  which  passes-out,  in  the 
proportion  of  1174  to  1000  ;  and  it  has  been  attempted  by  Valentin  and  Brunner3 
to  show,  that,  if  a  reasonable  allowance  be  made  for  accidental  causes  of  disturb- 
ance, this  is  the  actual  proportion  between  the  Oxygen  absorbed  and  the  carbonic 
ncid  given-out,  as  indicated  by  experiment.     Such,  however,  cannot  be  the  case, 

1  "  Physiologic  des  Athmens,"  pp.  102-149. 

a  "Ediub.  Med.  and  Surg.  Journal,"  1846. 

*  Valentin's  "  Lehrbuch  der  Physiologic,"  band  i.  pp.  507-580. 


EFFECTS    OF    RESPIRATION    ON    THE    AIR.  303 

since  the  departures  are  too  wide  to  be  accounted-for  on  this  hypothesis;  and  it 
is  easy  to  see  that  other  conditions  must  have  an  important  influence  in  modify- 
ing the  action.  For,  in  the  first  place,  the  membranous  septum  is  not  freely 
exposed  to  gases  on  both  sides;  but,  whilst  one  surface  is  in  contact  with  the 
atmosphere,  the  othei  is  in  contact  with  a  liquid  containing  gases,  these  being 
either  in  solution,  or  in  a  state  of  loose  chemical  combination.  With  regard  to 
that  part  of  the  gases  of  the  blood,  which  -is  simply  absorbed  mechanically,  it 
seems  probable  that  the  law  of  Henry  and  Dalton  holds  good ;  viz.,  that  the 
volume  of  gas  absorbed  by  a  liquid  depends  entirely  upon  the  pressure  under 
which  the  gas  above  it  remains,  after  the  absorption  has  been  completed  ;  and 
that,  in  the  case  of  mixed  gases,  this  proportion  is  determined  by  the  tension  of 
each  individual  gas.  The  quantity  of  carbonic  acid  passing  from  the  blood  to 
the  air-cells  would  therefore  depend,  on  the  one  hand,  upon  the  excess  of  this 
gas  condensed  in  the  blood;  and,  on  the  other,  upon  the  tension  of  the  carbonic 
acid  gas  already  contained  in  the  atmosphere  of  the  air-cells.  Conversely,  the 
blood  when  it  enters  the  lungs  not  being  saturated  with  oxygen,  is  able  to  absorb 
a  larger  quantity  under  the  pressure  which  it  there  experiences,  the  tension  of 
the  oxygen  contained  in  the  air-cells  being  considerable. — In  so  far  as  this  law  is 
in  operation,  then,  the  passage  of  each  gas  is  independent  of  that  of  the  other; 
but  it  does  not  apply  to  the  gases  that  nre  in  any  kind  of  chemical  combination 
with  the  constituents  of  the  blood;  and  further,  it  seems  likely  that  any  physical 
forces  of  the  kind  adverted-to  must  be  modified  in  their  action  by  the  difference 
of  permeability  which  animal  membranes  possess  for  different  gases. 

315.  The  recent  experiments  of  MM.  Regnault  and  Reiset1  appear  to  have 
furnished  the.  solution  of  the  wide  differences  in  the  estimates  which  various 
experimenters  have  given,  as  to  the  relative  amount  of  Oxygen  absorbed  and  of 
Carbonic  acid  exhaled;  by  showing  that  it  depends, — not,  as  Dulong  and  Despretz 
supposed,  upon  the  kind  of  animal  (the  proportion  of  oxygen '  absorbed  being 
much  larger  in  Carnivora  than  in  Herbivora),  —  but  upon  the  nature  of  the 
aliment  on  which  the  animal  is  fed  at  the  time  of  the  experiment.  Animals  fed 
on  flesh  absorb  much  more  oxygen  in  proportion,  than  those  fed  on  a  vegetable 
diet;  thus  in  a  dog  exclusively  nourished  on  flesh,  the  proportion  of  oxygen  ab- 
sorbed, to  100  parts  of  carbonic  acid  exhaled,  was  134-3,  or  much  above  that 
which  the  law  of  mutual  diffusion  would  indicate;  whilst  in  a  rabbit  fed  exclu- 
sively upon  vegetable  food,  the  proportion  of  oxygen  absorbed  was  only  109-34 
to  100  parts  of  carbonic  acid  exhaled,  or  less  than  the  calculated  amount.  The 
difference  between  the  relative  proportions  of  surplus  Oxygen,  in  the  same  animal, 
under  opposite  circumstances,  was  found  to  be  as  much  as  62  :  104.  It  is  not 
difficult  to  account  for  these  diversities,  when  we  bear  in  mind  the  different  com- 
position of  the  saccharine  carbo-hydrates,  of  oleaginous  substances,  and  of  bodies 
of  the  albuminous  type.  For  as,  in  sugar,  starch,  &c.,  the  hydrogen  is  already 
provided  with  its  equivalent  of  oxygen,  the  carbonic  acid  generated  by  their 
combustion  will  contain  the  whole  bulk  of  the  oxygen  consumed;  and  hence  the 
small  per-centage  of  oxygen  which  disappears  in  the  respiration  of  herbivorous 
animals,  must  be  appropriated  to  other  purposes  in  their  economy.  But  when 
the  material  consumed  is  fat,  the  oxygen  contained  in  the  carbonic  acid  that  is 
generated  will  be  only  71-32  per  cent,  of  the  whole  amount  that  disappears;  the 
remaining  28-68  per  cent,  being  appropriated  by  the  surplus  hydrogen  (that, 
namely,  for  which  the  substance  contained  no  equivalent  of  oxygen)  to  form 
water.  And  in  like  manner,  when  the  material  consumed  is  muscular  substance, 
only  83-60  per  cent,  of  the  oxygen  that  disappears  will  be  found  in  the  carbonic 
acid  generated;  the  remaining  16'40  forming  water  with  the  surplus  hydrogen.1 
The  disappearance  of  oxygen,  even  in  Herbivorous  animals,  is  thus  accounted-for 
by  the  circumstance,  that  part  of  the  materials  of  their  respiration  are  furnished 

1  "  Annales  de  Chiraie  et  de  Physique,"  1849. 

9  See  Prof.  Lehmann's  «'  Lehrbuch  der  Physiologischen  Cheinie,"  band  iii.  p.  314 


804  OF    KESPIRATION. 

by  the  disintegration  of  their  own  tissues;  with  regard  to  which,  therefore,  they 
are  on  the  footing  of  Carnivorous  animals.  And  this  view  is  borne-out  by  the 
curious  fact  ascertained  by  MM.  Regnault  and  Reiset,  and  confirmed  by  other 
experimenters,  that  when  an  animal  is  kept  fasting,  the  relation  between  the 
Oxygen  absorbed  and  the  Carbonic  acid  exhaled  is  nearly  the  same  as  when  the 
animal  is  fed  on  flesh;  the  reason  apparently  being,  that  in  the  former  case  the 
animal's  respiration  is  kept-up  at  the  expense  of  the  constituents  of  its  own  body, 
which  correspond  with  animal  food  in  their  composition. — There  can  be  no  doubt, 
then,  that,  on  the  whole,  a  considerable  surplus  of  oxygen  is  absorbed  into  the 
system  :  and  whilst  a  part  of  this  additional  oxygen  is  made  to  combine  with 
Hydrogen  furnished  by  the  food  or  by  the  disintegration  of  the  tissues^  the  water 
thus  generated  forming  part  of  that  exhaled  from  the  lungs,  another  part  will  be 
applied  to  the  oxidation  of  the  Sulphur  and  Phosphorus,  which  are  taken-in  as 
such  in  the  food,  and  which,  after  forming  part  of  the  solid  tissues,  are  excreted 
in  the  condition  of  sulphuric  and  phosphoric  acids,  chiefly  through  the  kidneys. 
It  also  appears,  from  the  recent  experiments  of  Dr.  Bence  Jones,1  that  the  action 
of  oxygen  is  exerted  in  the  system  upon  Ammonia,  and  probably  upon  other  pro- 
ducts of  decomposition  of  the  nitrogenous  tissues,  in  such  a  manner  as  to  produce 
Nitrous  or  Nitric  acid,  which  makes  its  appearance  in  the  urine. 

316.  The  absolute  quantity  of  Carbonic  Acid  exhaled  from  the  Lungs  is  liable 
to  variations  from  so  many  sources,  that  no  fixe.d  standard  can  be  assigned  for  it. 
The  mean  of  a  great  number  of  observations,  however,  made  in  different  modes, 
and  under  different  circumstances,  would  give  about  160  grains  of  Carbon  per 
hour  as  the  amount  set-free  by  a  well-grown  adult  man,  under  ordinary  circum- 
stances. Taking  this  as  the  average  of  the  twenty-four  hours,  the  total  quantity 
of  Carbon  thus  daily  expired  from  the  Lungs  would  be  3840  grains,  or  8  oz.  Troy. 
The  chief  causes  of  variation  are,  —  the  Temperature  and  Hygrometric  state  of 
the  surrounding  Medium,  Age,  Sex,  Development  of  the  body,  Nature  and  Quan- 
tity of  Food  and  state  of  the  Digestive  Process,  Muscular  Exertion  or  Repose, 
Sleep  or  Watchfulness,  Period  of  the  Day,  and  state  of  Health  or  Disease.  These 
will  now  be  considered  in  detail : — 

I.  Temperature  of  surrounding  Medium.  —  The  amount  of  Carbonic   Acid 
exhaled  by  warm-blooded  animals,  is  greatly  increased  by  external  Cold,  and 
diminished  by  Heat;  as  is  shown  by  the  following  results  of  comparative  experi- 
ments upon  the  quantity  set-free  by  the  same  animals,  at  low,  medium,  and  high 
temperatures,  in  periods  of  an  hour  (Letellier2) : — 

femp.  about  32°.  Temp.  59°— 68°.  Temp.  86°— 106°. 

Grammes.  Grammes.                          Grammes. 

A  Canary 0-325  0-250                        0-129 

A  Turtle-Dove 0-974  0-684                        0-336 

Two  Mice 0-531  0-498                        0-268 

A  Guinea-Pig  3-006  2-080                        1-453 

From  this  table  it  appears  that  the  quantity  of  carbonic  acid  exhaled  by  Mammals 
between  86°  and  106°,  is  less  than  half  that  set-free  near  the  freezing-point; 
whilst  that  which  is  exhaled  between  59°  and  68°  is  but  little  more  than  two- 
thirds  of  the  same  amount.  The  diminution  occasioned  by  heat  is  still  more 
remarkable  in  Birds ;  which  exhale  at  the  highest  temperature  scarcely  more  than 
one-third  of  that  set-free  at  the  lowest.  —  The  observations  of  "Vierordt3  upon 
himself  show  that  the  same  is  true  of  the  Human  subject;  a  difference  of  10° 
Fahr.,  according  to  him,  producing  a  variation  of  rather  more  than  two  cubic 
inches  in  the  amount  of  Carbonic  Acid  hourly  expired. 

II.  That  the  Hygrometric  state  of  the  Air  influences  the  rate  of  exhalation  of 

I  "Philosophical  Transactions,"  1851;  and  "Medical  Times,"  Aug.  30,  1851. 

II  "  Annales  de  Chimie  et  de  Physique,"  1845 ;  and,  M.  Boussingault's  "  Me"moires  de 
<.'himie  Agricole  et  de  Physiologic,1'  1854. 

"Physiologie  des  Athmens,"  pp.  73-82. 


EFFECTS    OF    BESPIRATION    ON    THE    AIR.  805 

Carbonic  Acid,  appears  from  some  experiments  of  Lehmann's  made  with  this 
express  view.  For  he  found  that  while  1000  grammes'  weight  of  Pigeons  yielded, 
in  dry  air,  6 '055  grammes  of  carbonic  acid  per  hour,  at  the  temperature  of  75°, 
and  4-69  grammes  at  the  temperature  of  100°,  the  same  animals,  in  moist  air, 
yielded  6-769  grammes  at  73°,  and  7-76  grammes  at  100°.  And  while  1000 
grammes'  weight  of  Rabbits  exhaled,  in  dry  air,  0-451  gramme  per  hour,  at  a 
temperature  of  100°,  they  exhaled  as  much  as  0-677  gramme  in  a  moist  atmo- 
sphere at  the  same  temperature.1 

in.  Age. — The  amount  of  Carbonic  Acid  exhaled  increases  in  both  sexes  up 
to  about  the  thirtieth  year ;  it  remains  stationary  until  about  the  forty-fifth ;  and 
it  then  diminishes.  The  following  are  the  comparative  results  of  experiments 
upon  males  of  different  ages,  and  of  a  moderate  degree  of  muscular  development 
(Andral  and  Gravarret2)  : — 

Carbon  exhaled  A  Carbon  exhaled 

per  hour.  per  hour. 

8  years 77-0  grains.  87  years 164-7  grains. 

12  "     113-9     »  48     "     161-7      " 

14     "     126-2     «  59     « 154-0      « 

20     "     166-3     "  68     "     147-8      » 

26     "     169-4     "  76     «     92-4      « 

IV.  Sex. — At  all  ages  beyond  eight  years,  the  exhalation  is  greater  in  Males 
than  in  Females.     Nearly  the  same  proportionate  increase  takes  place,  however, 
in  Females,  up  to  the  time  of  puberty;  when  the  quantity  abruptly  ceases  -to 
increase,  and  remains  stationary  so  long  as  they  continue  to  menstruate.     When, 
however,  menstruation  has  ceased,  the  exhalation  of  carbonic  acid  begins  again 
to  augment ;  and  then  again  diminishes,  with  the  advance  of  years,  as  in  men. 
Should  menstruation  temporarily  cease  at  any  time,  the  exhalation  of  carbonic 
acid  immediately  undergoes  an  increase,  precisely  as  at  the  fatal  cessation  of  the 
function.     And  during  pregnancy,  the  exhalation  increases  in  like  manner.     The 
following  table  of  the  comparative  respiration  of  Females  at  different  ages  will 
serve  at  the  same  time  for  comparison  with  the  preceding,  so  as  to  exhibit  the 
general  difference  between  the  two  sexes,  at  ages  nearly  corresponding;  and  also 
to  indicate  the  peculiar  modifications  induced  by  the  operations  of  the  genital 
system  (Andral  and  Gavarret)  : — 

Carbon  exhaled  A  Carbon  exhaled 

per  hour.  •*»*'  per  Iwur. 

10  years 92-4  grains. 

13  '•     97-0      " 

During  Menstrual  life.  During  Pregnancy. 

15^  years 97-0  grains.  22  years 129-3  grains. 

26       "     97-0     «  32     «     :...  126-7      " 

32      »     95-4     "  42     «     120-3      » 

45       "     95-4     « 

After  Cessation  of  Catamenia. 

38  years  120-3  grains.  66  years 104-7  grains. 

49     »      113-9      "  76     »     101-4      " 

52     «      115-5      "  82     «     92-4      " 

56     "      119-3      " 

V.  Development  of  the  Body.  — The  more  robust  the  individual,  cceteris  part- 
bus,  the  more  carbonic  acid  is  exhaled ;  and  the  variation  is  much  more  in- 
fluenced by  the  development  of  the  muscular  system,  than  by  the   height  or 
weight,  capacity  of  the  chest,  &c.     Thus,  a  very  strong  man  of  twenty-six  years 
of  age  exhaled  at  the  rate  of  217-1  grains  per  hour,  while  a  man  of  moderate 
muscular  power  set-free  but  1694  grains  in  the  same  time.     Another  robust 
man  of  sixty  years  of  age  exhaled  at  the  rate  of  209-4  per  hour;  another  of 
similar  constitution,  and  sixty-three  years  of  age,  at  the  rate  of  190-9  grains  per 

1  Lehmann,  Op.  cit.,  band  iii.,  p.  304. 
a  "  Annales  de  Chimie  et  de  Physique,"  1843. 
20 


806  OP    RESPIRATION. 

hour  ;  and  an  old  man  of  ninety-two  years,  who  still  preserved  an  uncommon 
degree  of  energy,  and  who  in  his  younger  days  had  boasted  of  extraordinary 
muscular  powers,  exhaled  at  the  rate  of  135-5  grains  per  hour.  So,  also,  a  re- 
markably vigorous  young  woman  of  nineteen  years,  exhaled  at  the  rate  of  107 '8 
grains  per  hour;  another  of  twenty-two  years,  rather  less  powerful,  at  the  rate 
of  103-1  grains;  and  a  strong  woman  of  forty-four  years  (who  had  ceased  to 
menstruate)  1524  grains. — On  the  other  hand,  a  slender  man  of  forty-five  years, 
in  the  enjoyment  of  good  health,  only  exhaled  at  the  rate  of  1324  grains  per 
hour  (Andral  and  Gravarret). 

VI.  Nature  and  Quantity  of  the  Food,  and  State  of  the  Digestive  Process.  — 
It  is  well  established,  that  the  exhalation  of  carbonic  acid  is  greatly  increased  by 
eating,  and  that  it  is  diminished  by  fasting.     Thus  Prof.  Scharlirig  states  tho 
hourly  exhalation  to  have  increased  in  one  instance  from  145  to  190,  after  break- 
fast and  a  walk;  in  another  from  140  to  177,  after  breakfast  alone;  and  in  an- 
other from  111-9  to  188-9,  after  dinner.     Tne  observations  of  Vierordt  are  to 
the  same  effect.     So,  again,  it  has  been  found  by  Bidder  and  Schmidt,  that  whilst 
a  Cat,  fed  on  an  allowance  of  meat  which  was  found  to  be  adequate  to  maintain 
its  full  strength  and  ordinary  weight,  exhaled  65 '60  grammes  of  carbonic  acid 
per  diem,  the  same  animal,  consuming  nearly  double  that  amount  of  food,  exhaled 
nearly  double  the  amount  of  carbonic  acid.     Similar  results  were  obtained  by 
MM.  Regnault  and  Reiset,  who  found  that  when  animals  were  over-fed  with  the 
saccharine  hydrocarbons,  the  proportion  of  the  carbonic  acid  exhaled,  to  that  of 
the  other  products  of  combustion,  underwent  such  an  increase,  that  it  contained 
95  or  even  99-7  per  cent,  of  the  oxygen  which  had  disappeared.  —  On  the  other 
hand,  the  use  of  Alcoholic  drinks  tends  to  diminish  the  exhalation  of  carbonic 
acid ;  and  this  not  merely  (as  maintained  by  some)  in  virtue  of  the  large  propor- 
tion of  surplus  hydrogen  contained  in  alcohol,  but  also  (as  there  appears  strong 
reason  to  believe)  by  obstructing  the  normal  oxidation  and  elimination  of  other 
combustible  materials  which  the  blood  may  contain.     For  it  is  shown  by  the  ex- 
periments of  Dr.  Prout,1  which  have  been  confirmed  as  to  many  points  by  those 
of  Vierordt,  that  this  diminution  continues  so  long  as  the  alcohol  remains  uncon- 
sumed  in  the  system,  and  is  then  followed  by  a  marked  increase  in  the  per-cent- 
age  of  carbonic  acid  in  the  inspired  air. 

VII.  Muscular  Exertion  or  Repose.  —  The  effect  of  bodily  exercise,  in  mode- 
ration, is  to  produce  a  considerable  increase  in  the  amount  of  carbonic  acid 
exhaled,  both  during  its  continuance,  and  for  some  little  time  subsequently  to  its 
cessation.     According  to  the  observations  of  Vierordt,  the  increase  amounts  to 
one-third  of  the  quantity  exhaled  during  rest;  and  it  lasts  for  more  than  an  hour 
afterwards,  being  manifested  in  the  greater  quantity  of  air  respired,  and  in  the 
larger  per-centage  of  carbonic  acid  contained  in  it.     If  the  exercise  be  pro- 
longed, however,  so  as  to  occasion  fatigue,  it  is  succeeded  by  a  diminished  exha- 
lation.—  The  connection  between  muscular  exertion  and  the  exhalation  of  car- 
bonic acid,  is  remarkably  shown  in  Insects ;  in  which  animals  we  may  witness 
the  rapid  transition  between  the  opposite  conditions  of  extreme  muscular  exer- 
tion, and  tranquil  repose ;  and  in  which  the  effects  of  these  upon  the  respiratory 
process  are  not  masked  by  that  exhalation  of  carbonic  acid,  which  is  required  in 
warm-blooded  animals  simply  for  the  maintenance  of  a  fixed  temperature.     Thus 
a  Humble-Bee  was  found  by  Mr.  Newport2  to  produce  one-third  of  a  cubic  inch 
of  carbonic  acid,  in  the  course  of  a  single  hour,  during  which  its  whole  body 
was  in  a  state  of  constant  movement,  from  the  excitement  resulting  from  its  cap- 
ture; and  yet,  during  the  whole  twenty -four  hours  of  the  succeeding  day,  which 
it  passed  in  a  state  of  comparative  rest,  the  quantity  of  carbonic  acid  generated 
by  it  was  absolutely  less. 

VIII.  Sleep  or  Watchfulness. — The  amount  of  carbonic  acid  exhaled  during 

1  "  Thomson's  Annals  of  Philosophy,"  vols.  ii.  and  iv. 
J  "  Philos.  Transact.,"  1836 


EFFECTS  OF  RESPIRATION  ON  THE  AIR.      307 

sleep,  is  considerably  less  than  that  set-free  in  the  waking  state.  This  is  par- 
ticularly shown  by  the  experiments  of  Scharling;1  who  confined  the  subjects  of 
them  in  an  air-tight  chamber,  within  which  they  could  sleep,  take  their  meals, 
&c.  Thus  in  one  case,  the  hourly  exhalation  sank  from  160  to  100,  in  another 
from  194-7  to  122-3,  and  in  another  from  99  to  75-1.  The  cause  of  this  result 
is  partly  to  be  sought  in  the  cessation  of  all  muscular  exertion  (save  that  con- 
cerned in  the  maintenance  of  the  respiration) ;  and  partly  in  the  diminution  in 
the  dissipation  of  the  heat  of  the  body  itself. 

ix.  Period  of  the  Day. — Independently  of  these  variations,  which  have  their 
source  in  the  condition  of  the  individual,  there  is  reason  to  believe  that  there  is 
a  diurnal  cycle  of  change  in  the  quantity  of  carbonic  acid  exhaled,  the  maximum 
being  (caeteris  paribus)  before  and  after  noon,  and  the  minimum  before  and 
after  midnight.  From  the  experiments  of  Scharling  upon  the  Human  subject, 
it  would  appear  that  the  average  proportion  exhaled  by  day  to  that  exhaled  by 
night,  is  as  1 J  to  1 ;  and  this  difference  does  not  seem  to  be  affected  by  sleep  or 
wakefulness.  How  far  it  is  to  be  accounted-for  by  other  differences  in  the  con- 
dition of  the  system,  it  does  not  seem  easy  to  determine.  But  it  is  pretty  ob- 
viously associated  with  a  difference  in  the  power  of  generating  heat;  for  accord- 
ing to  the  observations  of  Ghossat  (CHAP,  x.),  there  is  a  like  diurnal  variation  in 
the  temperature  of  Birds ;  and  most  persons  are  conscious  of  a  greater  difficulty 
in  bearing  exposure  to  cold  between  midnight  and  early  morning,  than  at  any 
other  period  in  the  twenty-four  hours. 

x.  State  of  Health  or  Disease. — Upon  this  very  important  cause  of  variation, 
few  accurate  researches  have  yet  been  made.  The  per-centage  of  carbonic  acid 
in  the  expired  air  has  been  found  to  be  unusually  great  in  the  Exanthemata, 
and  in  chronic  Skin-diseases  (Macgregor2);  and  it  has  been  stated  to  be  dimi- 
nished in  Typhus  (Malcolm3). — Thus,  the  average  proportion  in  health  being 
about  4-3  per  cent.  (Vierordt),  it  has  been  seen  at  8  per  cent,  in  confluent  Small- 
pox, at  5  per  cent,  in  Measles,  and  at  7*2  per  cent,  in  a  severe  case  of  Ichtbyosis 
which  terminated  fatally;  whilst  in  Typhus  the  per-centage  has  been  found  to 
range  from  1-18  to  2-50.  But  these  statements  do  not  indicate  the  total  quan- 
tity exhaled  in  each  case.  —  The  remarkable  increase  of  the  exhalation  in  cases 
of  Chlorosis,  has  been  already  noticed ;  in  four  cases  recorded  by  Hannover,  the 
hourly  expiration  was  123-6,  118-6,  116-9,  and  106-3  grains;  the  absolute  quan- 
tity diminishing  as  the  respirations  increased  in  rapidity.  —  In  chronic  diseases 
of  the  respiratory  organs,  as  might  be  anticipated,  the  amount  of  Carbonic  acid 
exhaled  undergoes  a  sensible  diminution  (Nysten4  and  Hannover5). —  Further 
researches  are  much  needed  on  this  subject;  but,  for  obvious  reasons,  they  cannot 
be  readily  made  in  severe  forms  of  disease. 

317.  The  aeration  of  the  blood  may  take  place,  not  only  by  means  of  the 
Lungs,  but  also  in  some  degree  through  the  medium  of  the  Cutaneous  surface. 
In  some  of  the  lower  tribes  of  animals,  indeed,  this  is  a  very  important  part  of 
their  respiratory  process :  and  even  in  certain  Vertebrata,  the  cutaneous  respira- 
tion is  capable  of  supporting  life  for  a  considerable  time.  This  is  especially  the 
case  in  the  Batrachia,  whose  skin  is  soft,  thin,  and  moist;  and  the  effect  is  here 
the  greater,  since,  from  the  small  proportion  of  the  blood  that  has  passed  through 
the  lungs,  that  which  circulates  through  the  system  is  very  imperfectly  arterial- 
ized.  By  the  experiments  of  Bischoff  it  was  ascertained  that,  even  after  the 
lungs  of  a  Frog  had  been  removed,  a  quarter  of  a  cubic  inch  of  sarbonic  acid 
was  exhaled  from  the  skin,  in  the  course  of  eight  hours.  Experiments  en  the 
Human  subject  leave  no  room  for  doubt,  that  a  similar  process  is  effected  through 

1  "Ann.  der  Chem.  und  Pharra.,"  1843;  transl.  in  'Ann.  de  Chim.  et  de  Phys.,"  1843. 

3  "  Edinb.  Monthly  Journal,"  1843.  3  "  Report  of  Brit.  Assoc.,"  1843,  p.  87. 

4  "Recherches  de  Physiologic  et  de  Chemie  Pathologique,"  1811. 

'  "  De  Quantitate  relativa  et  absoluta  Acidi  Carbonici  ab  Homine  Sano  et  ^Egroto  exha- 
lati,"  1845. 


308  OF    RESPIRATION. 

the  medium  of  his  general  surface,  although  in  a  very  inferior  degree  ;  for  by 
confining  the  body  in  a  close  chamber,  into  which  the  products  of  cutaneous 
respiration  could  freely  pass,  whilst  the  pulmonary  respiration  was  measured  by 
a  distinct  apparatus,  Prof.  Scharling  '  ascertained  that  the  proportion  of  carbonic 
acid  given-off  by  the  Skin  is  from  l-30th  to  l-60th  of  that  exhaled  from  the 
Lungs  during  the  same  period  of  time.  Moreover,  it  has  been  observed,  not  un- 
frequently,  that  the  livid  tint  of  the  skin  which  supervenes  in  Asphyxia,  owing 
to  the  non-arterialization  of  the  blood  in  the  lungs,  has  given  place  after  death 
to  the  fresh  hue  of  health,  owing  to  the  reddening  of  the  blood  in  the  cutaneous 
capillaries  by  the  action  of  the  atmosphere  upon  them;  and  it  does  not  seem  im- 
probable that,  in  cases  of  obstruction  to  the  due  action  of  the  lungs,  the  exhala- 
tion of  carbonic  acid  through  the  skin  may  undergo  a  considerable  increase  ;  for 
we  find  a  similar  disposition  to  vicarious  action  in  other  parts  of  the  excreting 
apparatus.  Moreover,  there  is  evidence  that  the  interchange  of  gases  between 
the  air  and  the  blood,  through  the  skin,  has  an  important  share  in  keeping-up 
the  temperature  of  the  body  (CHAP,  x.)  ;  and  we  find  the  temperature  of  the 
surface  much  elevated  in  many  cases  of  pneumonia,  phthisis,  &c.7  in  which  the 
lun'gs  seem  to  perform  .their  function  very  insufficiently. 

318.  The  total  amount  of  Carbonic  acid  daily  given-off  from  the  Skin  and 
Lungs  may  be  estimated  in  another  mode  ;  namely,  by  determining  the  total 
amount  of  Carbon  contained  in  the  ingesta,  and  the  amount  excreted  in  other 
ways,  making  allowance  for  the  difference  in  weight  (if  any)  of  the  body.  In 
this  mode,  Prof.  Liebig  came  to  the  conclusion,  that  the  average  amount  of  car- 
bon exhaled  by  soldiers  in  barracks,  was  13-9  oz.  (Hessian)  or  very  nearly  14  oz. 
troy.2  From  similar  collective  observations  upon  the  inmates  of  the  Bridewell 
at  Marienschloss  (a  prison  where  labour  is  enforced),  he  calculates  that  each  in- 
dividual exhaled  10-5  oz.  of  carbon  daily  in  the  form  of  carbonic  acid;  while  in 
a  prison  at  Giessen,  whose  inmates  are  deprived  of  all  exercise,  the  daily  average 
was  but  8-5  oz.3  It  has  been  shown  by  Prof.  Scharling,4  that  the  total  amount 
of  carbon  contained  in  the  daily  allowance  of  food  and  drink  in  the  Danish  Navy, 
is  somewhat  less  than  10-5  oz.  ;  and  as  we  shall  presently  see  that  from  l-10th  to 
l-12th  of  the  carbon  ingested  passes-off  through  other  channels,  scarcely  more 
than  9  -5  oz.  of  this  amount  can  be  consumed  by  the  respiratory  process.  —  A  very 
exact  estimate,  though  based  on  more  limited  data,  has  been  recently  made  by 
M.  Barral  ;  5  who  experimented  upon  himself  (set.  29)  in  winter  (A)  and  in  sum- 
mer (B),  upon  a  boy  of  6  years  old  (c),  upon  a  man  of  59  years  old  (D),  and  upon 
an  unmarried  woman  of  32  years  (E).  The  following  table  gives  the  results 
which  he  obtained,  from  an  average  of  five  days,  in  regard  to  the  disposal  of  the 
Carbon  of  the  food  ;  those  which  relate  to  its  Nitrogen,  Hydrogen,  and  Oxygen 
will  be  noticed  subsequently  (§§  320,  321). 

Weight  of  Body.  Carbon  of  Food.  Carbon  excreted. 


In  Faeces. 

In  Urine. 

By  exhalation. 

A 

104-5  Ibs. 

5654-1  grs. 

236-2  grs. 

234-6  grs. 

5183-3  grs. 

B 



4090-0  " 

U37-4  " 

211-5  " 

3741-1  « 

C 

33      " 

2382-3  " 

149-7  " 

67-9  « 

2164-7  " 

D 

129-1  " 

5123-0  " 

210-0  " 

327-3  " 

4585-7  " 

E 

134-6  " 

4520-8  " 

64-8  " 

216-1  " 

4239-9  " 

*  "Ann.  der  Chem.  und  Pharm.,"  1846. 

1  "Animal  Chemistry,"  3rd  edit.  p.  13.  —  The  mode  in  which  this  estimate  was  made, 
however,  was  very  far  from  exact  ;  as  it  rests  on  the  assumption  that  the  carbon  of  the 
faeces  and  urine  was  no  more  than  equal  to  that  of  certain  extra  articles  of  diet  supposed 
to  have  been  consumed,  and  that  all  the  carbon  of  the  regular  allowance  of  bread,  meat, 
and  vegetables,  must  have  passed-off  by  the  atmosphere.  Its  great  discordance  with  other 
results  leaves  little  room  for  doubt,  that  even  if  not  far  from  being  true  for  the  particular 
case,  it  cannot  be  admitted  as  representing  the  usual  average. 

«  Op.  cit.  p.  46.  4  "  Ann.  der  Chem.  und  Pharm.,"  1846. 

"Ann.  de  Chim.  et  de  Phys.,"  torn.  xxv. 


EFFECTS  OF  RESPIRATION  ON  THE  AIR.      309 

Thus  the  average  amount  of  the  carbon  daily  consumed  in  pulmonary  and  cuta- 
neous exhalation  by  M.  Barral  himself,  was  in  winter  5183-3  grains,  or  10-8  oz. 
troy ;  whilst  in  summer  it  was  but  3741-1  grains,  or  7-8  oz.  troy;  this  difference  | 
is  quite  conformable  to  what  might  have  been  anticipated  from  the  results  of  a  i 
different  mode  of  experimenting  (§  316  i) ;  and  it  throws  some  light  on  the  dis- 
crepancies in  the  results  of  other  measurements,  to  find  that  the  seasonal  varia- 
tion is  scarcely  less  than  one-third  of  the  mean  between  these  two  amounts.  The 
other  results  correspond  closely  with  the  statements  of  MM.  Andral  and  Gavar- 
ret,  in  regard  to  the  higher  proportion  of  carbonic  acid  exhaled  (as  compared 
with  the  bulk  of  the  body)  by  children,  and  the  smaller  proportion  thrown-off 
by  men  advanced  in  years,  and  by  women. 

319.  It  is  not  only  by  an  oxygenated  atmosphere,  that  the  removal  of  Carbonic 
acid  from  the  blood  may  be  effected.  For  although  it  was  formerly  supposed  that 
the  exhaled  carbonic  acid  is  generated  in  the  lungs  by  the  combination  of  atmo- 
spheric oxygen  with  the  carbonaceous  matters  of  the  blood,  and  that  the  inhala- 
tion of  oxygen  is  therefore  immediately  necessary  for  its  production,  yet  it  is 
now  quite  certain  that  this  carbonic  acid  exists  preformed  in  venous  blood,  and 
that  the  oxygen  introduced  is  carried  into  the  arterial  circulation,  instead  of  being 
at  once  returned  to  the  air  in  the  state  of  carbonic  acid  (§  179).  Hence  an 
exhalation  of  carbonic  acid  may  continue  for  a  considerable  period  (in  cold- 
blooded animals  especially),  whilst  the  animal  is  breathing  an  atmosphere  in 
which  no  oxygen  exists.  Thus  it  was  shown  by  Spallanzani,1  that  Snails  might 
be  kept  for  a  long  time  in  Hydrogen,  without  apparent  injury  to  them ;  and  that 
during  this  period  they  disengaged  a  considerable  amount  of  Carbonic  acid.  Dr. 
Edwards2  subsequently  ascertained  that,  when  Frogs  were  kept  in  hydrogen  for 
several  hours,  the  quantity  of  carbonic  acid  exhaled  was  fully  as  great  as  it  would 
have  been  in  atmospheric  air,  or  even  greater ;  this  latter  fact,  if  correct,  may 
be  accounted-for  by  the  superior  displacing  power,  which  (on  the  laws  of  the 
diffusion  of  gases)  hydrogen  possesses  for  carbonic  acid.  Collard  de  Martigny3 
repeated  this  experiment  in  Nitrogen,  with  the  same  results.  In  both  sets  of 
experiments,  the  precaution  was  used  of  compressing  the  flanks  of  the  animal, 
previously  to  immersing  it  in  the  gas,  so  as  to  expel  from  the  lungs  whatever 
mixture  of  oxygen  they  might  contain.  These  experiments  have  been  since 
repeated  by  Miiller  and  Bergemann,  who  took  the  additional  precaution  of  re- 
moving, by  means  of  the  air-pump,  all  the  atmospheric  air  that  the  lungs  of  the 
frog  might  previously  contain,  together  with  the  carbonic  acid  that  might  exist 
in  the  alimentary  canal.  They  found  in  one  of  their  experiments,  that  the  quan- 
tity of  carbonic  acid  exhaled  in  hydrogen  was  nearly  a  cubic  inch  in  6&  hours; 
and  in  another,  that  nearly  the  same  amount  was  given-off  in  nitrogen,  though 
this  required  rather  a  longer  period.  It  appears  from  the  table  of  their  results,4 
that  the  amount  was  not  ordinarily  greater  in  the  experiments  which  were  pro- 
longed for  twelve  or  fourteen  hours,  than  in  those  which  were  terminated  in 
half  the  time ;  hence  it  may  be  inferred,  that  the  quantity  which  the  blood  is 
itself  capable  of  disengaging  is  limited,  and  that  the  absorption  of  oxygen  is 
necessary  to  enable  carbonic  acid  to  be  continuously  set-free  from  the  body. — It 
is  impossible,  however,  for  an  adult  Bird  or  Mammal  to  sustain  life  for  any  con- 
siderable time  in  an  atmosphere  deprived  of  oxygen ;  since  the  greatly-increased 
rapidity  and  energy  of  all  their  vital  operations,  necessitate  a  much  more  con- 
stant supply  of  this  vivifying  agent,  than  is  needed  by  the  inferior  tribes;  and, 
as  we  shall  presently  see,  the  capillary  action  requisite  for  the  passage  of  the 
blood  through  the  lungs  will  not  take  place  without  it  (§  327).  But  Dr.  Edwarda 
has  shown,  that  young  Mammalia  can  sustain  life  in  an  atmosphere  of  hydrogen 

*  "  Me*moires  sur  la  Respiration,"  traduits  par  Senebeir,  Geneve,  1804. 

9  "De  1'Influence  des  Agens  Physiques  sur  la  Vie  ;"  Paris,  1824. 

'  «  Recherches  Expe"rimen tales,'  &c.  in  Magendie's  "  Journal  de  Physiologic,"  torn  x. 

4  ««  Miiller's  Elements  of  Physiology,"  translated  by  Baly,  vol.  i.,  p.  338. 


310  OF    RESPIRATION. 

or  nitrogen,  for  a  sufficient  length  of  time  to  exhale  a  sensible  amount  of  car- 
bonic acid ;  so  that  the  character  of  the  process  is  clearly  proved  to  be  the  same 
in  warm-blooded  animals,  as  in  Reptiles  and  Tnvertebrata. 

320.  Much  discussion  has  taken  place,  with  regard  to  the  degree  in  which  the 
proportion  of  Nitrogen  in  the  air  is  affected  by  Respiration.     It  seems  probable 
that  the  absorption  and  exhalation  of  this  gas  are  continually  taking  place ;  but 
that  the  two  amounts  usually  nearly  balance  each  other.1     On  the  whole,  how- 
ever, there  is  adequate  reason  to  believe  that  Nitrogen  is  ordinarily  given-off; 
this  being  the  joint  result  of  the  analysis  of  the  expired  air,  and  of  the  compari- 
son of  the  amount  of  nitrogen  given-off  in  the  other  excretions  with  that  ingested 
as  a  constituent  of  the  food.     Of  the  experiments  made  in  the  former  of  these 
methods,  the  most  accurate  are  those  of  MM.  Regnault  and  Reiset,  whose  general 
conclusions  are  as  follows  :  —  (1).  That  warm-blooded  animals  subjected  to  their 
ordinary  regimen  exhale  nitrogen,  but  never  in  larger  proportion  than  l-50th, 
and  sometimes  in  less  than  l-100th,  of  the  oxygen  consumed :  —  (2).  That  in  a 
state  of  inanition,  animals  usually  absorb  nitrogen:  —  (3).  That  animals  whose 
usual  diet  has  been  changed,  usually  absorb  oxygen  until  they  are  accustomed  to 
their  new  food.2 — Of  the  experiments  made  according  to  the  second  method, 
those  of  M.  Boussingault  upon  turtle-doves,  and  those  of  M.  Barral  upon  the 
human  subject,  appear  to  be  trustworthy.     The  former  states  that  the  surplus  of 
nitrogen  in  the  food  of  the  bird,  above  that  excreted  by  the  kidneys  and  intes- 
tinal canal,  is  2J  grains  daily,  or  one-third  of  the  weight  of  the  azote  in  its  food  ;3 
whilst  the  latter  gives  the  following  as  the  results  of  his  observations  upon  him- 
self and  the  other  individuals  already  referred-to  (§  318): — 

Nitrogen  in  Food.  .  Nitrogen  excreted. 

A  432-3  grs. 

B  327-3    « 

C  121-9    « 

D  421-5    « 

E  345-8    " 

In  cases  A,  B,  and  E,  the  amount  of  Nitrogen  which  (being  otherwise  unaccounted- 
for)  must  be  considered  to  have  passed-off  by  the  lungs  and  skin,  was  about 
l-75th  of  the  oxygen  consumed ;  a  proportion  which  accords  very  well  with  that 
deduced  by  MM.  Regnault  and  Reiset  from  their  experiments  on  animals.  In 
case  D,  however,  it  was  only  l-97th  j  and  in  case  c  (that  of  a  child  of  six  years 
old),  it  was  as  little  as  l-143rd. — It  will  be  remembered  that  Nitrogen  exists  in 
an  uncombined  state  in  the  blood  (§  179);  its  per-centage,  however,  is  continually 
varying ;  and  no  constant  difference  is  observable  between  the  proportions  yielded 
by  arterial  and  venous  blood  respectively. 

[The  alterations  effected  in  the  Blood  by  Respiration  have  already  been  fully 
considered.     See  §§  179-182.] 

321.  Exhalation  and  Absorption  through  the  Lungs. — The  Air  expired  from 
the  lungs  differs  from  that  which  was  introduced  into  them,  not  merely  in  the 
altered  proportions  of  its  Oxygen,  Nitrogen,  and  Carbonic  acid,  but  also  in  having 
received  (under  ordinary  circumstances  at  least)  a  large  addition  to  its  watery 
vapour.     This  it  doubtless  acquires  in  accordance  with  physical  laws,  through  its 
exposure  to  the  warm  blood  which  is  spread-out  over  a  very  extensive  surface,  the 
intermediate  membrane  being  extremely  permeable;   and  the  variations  in  its 
amount  will  depend  upon  the  physical  conditions  under  which  that  exposure 
takes  place.     The  air  expired  in  ordinary  respiration  is  charged  with  as  much 
watery  vapour  as  saturates  it  at  the  temperature  of  the  body ;  and  consequently 

1  For  the  considerations  which  render  this  probable,  see  especially  Dr.  W.  F.  Edwards 
"  On  the  Influence  of  Physical  Agents  on  Life,"  Part  iv.,  chap.  xvi.  sect.  2,  3. 
*  "Ann.  de  Chim.  et  de  Phys.,"  1849;  and  "Mem.  de  Chim.  Agric.,"  1854,  p.  31. 
"Comptes  Rendus,"  1846. 


Urine. 

Fasces. 

Lungs  and  Skin. 

168-3  grs. 

43-2  grs. 

220-8  grs. 

151-3    « 

20-1    " 

155-9    " 

47-8    « 

27.8    " 

46-3    « 

234-6    " 

38-6    « 

148-3    » 

154-4    " 

12-3    " 

179-1    » 

EXHALATION    AND    ABSORPTION   THROUGH    THE    LUNGS.  811 

the  amount  of  watery  vapour  thus  exhaled,  will  vary  (for  equal  volumes  of  air  at 
any  given  temperature)  in  the  inverse  proportion  to  that  which  the  air  previously 
contained.  But  when  the  air  is  very  cold  and  very  dry,  and  the  respiration  is 
unusually  rapid,  it  may  not  remain  sufficiently  long  in  the  air-cells,  to  be  raised 
to  the  temperature  of  the  body,  or  to  be  fully  saturated  with  moisture.  The 
amount  of  watery  vapour  exhaled,  moreover,  will  of  course  depend  in  part  upon 
the  quantity  of  air  which  passes  through  the  lungs.  And  from  these  causes  of 
difference,  it  happens  that  the  amount  of  watery  vapour  exhaled  in  twenty-four 
hours  may  vary  from  about  6  oz.  to  27  oz. ;  its  usual  range,  however,  being  be- 
tween 16  and  20  oz.  —  Of  the  fluid  ordinarily  exhaled  with  the  breath,  a  part 
doubtless  proceeds  from  the  moist  lining  of  the  nostrils,  fauces,  &c. ;  but  it  is 
indisputable  that  the  greater  proportion  of  it  comes  from  the  lungs,  since,  when 
the  respiration  is  entirely  performed  through  a  canula  introduced  into  the  trachea, 
the  amount  of  watery  vapour  which  the  breath  contains  is  still  very  considerable. 
Of  the  proper  pulmonary  exhalation,  there  can  be  no  doubt  that  the  greater  part 
is  the  mere  surplus-water  of  the  blood,  and  especially  of  the  crude  fluid  which 
has  been  newly  introduced  into  the  circulating  current  by  the  process  of  nutritive 
absorption.  But  there  is  strong  evidence  that  Hydrogen  as  well  as  carbon  un-' 
dergoes  combustion  in  the  system ;  and  that  a  portion  of  the  exhaled  aqueous 
vapour  is  the  product  of  that  combustion.  For  of  the  hydrogen  which  the  food 
contains,  not  more  than  from  l-8th  to  1-lOth  passes-off  by  the  other  excretions, 
the  remaining  7-8ths  or  9-10ths  being  exhaled  in  the  condition  of  watery  vapour 
from  the  lungs.  A  portion  of  the  oxygen  which  this  vapour  contains,  is  sup- 
plied by  the  food ;  but  there  is  usually  a  considerable  surplus  of  hydrogen  j  and 
this  can  only  be  converted  into  water,  at  the  expense  of  oxygen  derived  from  the 
atmosphere.  Upon  this  point  the  experiments  of  M.  Barral  (loc.  cit.)  gave  the 
following  results : — 


Oxygen  exhaled, 
A        3841-4  grs. 
B        2757-6  " 
C        1880-6  " 
D        3795-1  " 
E        3140-5  « 

Equiv.  of  Hydrogen. 
480-2  grs. 
344-7  " 
235-1  « 
474-4  « 
392-5  « 

Hydrogen  exhaled. 
801-3  grs. 
597-5  " 
330-4  " 
662-3  « 
643-8  « 

Difference. 
321-1  grs. 
252-8  « 
95-3  « 
187-9  « 
251-3  " 

Thus  it  appears  that,  of  the  hydrogen  exhaled  from  the  lungs  and  skin  of  M. 
Barral,  in  the  condition  of  watery  vapour,  not  less  than  321-1  grs.  in  winter,  and 
252-8  grains  in  summer,  must  have  been  converted  into  water  by  oxygen  derived 
from  the  air;  and  this  calculation  would  give  2889-9  grs.  (6  oz.  troy)  for  the 
winter,  and  2275-2  grs.  (4-7  oz.  troy)  for  the  summer,  as  the  amount  of  water 
thus  generated  in  the  combustive  process.  This,  however,  can  only  be  regarded 
as  an  approximation  to  the  truth ;  since  there  are  many  circumstances  not  taken 
into  account  in  the  computation,  by  which  the  estimate  may  be  affected. 

322.  The  fluid  thrown-off  from  the  lungs  is  not  pure  Water.  It  holds  in 
solution,  as  might  have  been  expected,  a  considerable  amount  of  carbonic  acid, 
and  also  some  animal  matter ;  the  exact  nature  of  the  latter,  which  according  to 
Collard  de  Martigny  (op.  cit.)  constitutes  about  3  parts  in  1000,  has  not  been 
ascertained;  but  from  the  inquiries  of  Mr.  R.  A.  Smith,1  it  would  appear  to  be 
an  albuminous  substance  in  a  state  of  decomposition.  If  the  fluid  be  kept  in  a 
closed  vessel,  and  be  exposed  to  an  elevated  temperature,  a  very  evident  putrid 
odour  is  exhaled  by  it.  Every  one  knows  that  the  breath  itself  has,  occasionally 
in  some  persons,  and  constantly  in  others,  a  foetid  taint :  when  this  does  not 
proceed  from  carious  teeth,  ulcerations  in  the  air-passages,  disease  in  the  lungs, 
or  other  similar  causes,  it  must  result  from  the  excretion  of  the  odorous  mattei, 
in  combination  with  watery  vapour,  from  the  pulmonary  surface.  That  this  is 
the  true  account  of  it,  seems  evident  from  the  analogous  phenomenon  of  the 
excretion  of  turpentine,  camphor,  alcohol,  and  other  odorous  substances,  which 
1  "  Philosophical  Magazine,"  vol.  xxx.  p.  478. 


312  OF    RESPIRATION. 

have  been  introduced  into  the  venous  system,  either  by  natural  absorption,  or  by 
direct  injection ;  and  also  from  the  suddenness  with  which  it  often  manifests 
itself,  when  the  digestive  apparatus  is  slightly  disordered,  apparently  in  conse- 
quence of  the  entrance  of  some  mal-assimilated  matter  into  the  blood.  Among 
the  substances  occasionally  thrown-off  by  the  lungs,  Phosphorus  deserves  a  special 
mention,  on  account  of  the  peculiarity  of  the  form  under  which  it  is  eliminated ; 
for  it  has  been  found  that  if  phosphorus  be  mixed  with  oil,  and  be  injected  into 
the  blood-vessels,  it  partly  escapes  in  an  unoxidized  state  from  the  lungs,  render- 
ing the  breath  luminous.1  And  this  luminous  breath  has  also  been  observed  in 
spirit-drinkers;  in  whom  the  oxidation  of  the  effete  matters  of  the  system  is 
impeded,  in  consequence  of  the  demand  set-up  by  the  alcohol  ingested  for  the 
oxygen  introduced  (§316  vin.) 

323.  Not  only  exhalation,  but  also  (under  peculiar  circumstances)  absorption 
of  fluid  may  take  place  through  the  Lungs.     Thus  Dr.  Madden 2  has  shown  that, 
if  the  vapour  of  hot  water  be  inhaled  for  some  time  together,  the  total  loss  by 
exhalation  is  so  much  less  than  usual,  as  to  indicate  that  the  cutaneous  transpi- 
ration is  partly  counterbalanced  by  pulmonary  absorption ;  the  pulmonary  exha- 
lation being  at  the  same  time  entirely  checked.     It  is  probable  that,  if  the  quan- 
tity of  fluid  in  the  blood  had  been  previously  diminished  by  excessive  sweating, 
or  by  other  copious  fluid  secretions,  the  pulmonary  absorption  would  have  been 
much  greater.     Still  in  the  cases  formerly  mentioned  (§  129),  in  which  a  large 
increase  in  weight  could  only  be  accounted-for  on  the  supposition  of  absorption 
of  water  from  the  atmosphere,  it  seems  probable  that  the  cutaneous  surface  was 
chiefly  concerned ;  for  it  can  only  be  when  the  air  introduced  into  the  lungs  is 
saturated  with  watery  vapour,  that  the  usual  exhalation  will  be  checked,  or  that 
any  absorption  can  take  place. 

324.  That  absorption  of  other  volatile  matters  diffused  through  the  air.  is, 
however,  continually  taking  place  by  the  lungs,  is  easily  demonstrated.     A  fami- 
liar example  is  the  effect  of  the  inhalation  of  the  vapour  of  Turpentine  upon  the 
urinary  excretion.     It  can  only  be  in  this  manner  that  those  gases  act  upon  the 
system,  which  have  a  noxious  or  poisonous  effect,  when  mingled  in  small  quan- 
tities in  the  atmosphere ;  and  it  is  most  astonishing  to  witness  the  extraordinary 
increase  in  potency  which  many  substances  exhibit,  when  they  are  brought  into 
relation  with  the  blood  in  the  gaseous  form.     The  most  remarkable  example  of 
this  kind  is  afforded  by  Arseniuretted  Hydrogen,  the  inspiration  of  a  few  hun- 
dred ths  of  a  grain  of  which  has  been  productive  of  fatal  consequences,  the  re- 
sulting symptoms  being  those  of  arsenical  poisoning.     Next  to  this,  perhaps,  in 
deleterious  activity,  is  Sulphuretted  Hydrogen  ;  but  it  would  seem  that  the  effects 
of  this  gas  upon  the  Human  subject  are  scarcely  so  violent  as  they  are  upon 
animals;  for  though  it  has  been  found  that  the  presence  of  l-1500rh  part  of  it 
in  the  respired  air  will  destroy  a  bird  in  a  very  short  time,  that  l-800th  part 
suffices  to  kill  a  dog,  and  that  l-250th  part  is  fatal  to  a  horse,  yet  Mr.  Parent- 
Duchatelet  has  affirmed  that  workmen  habitually  breathe  with  impunity  an  atmo- 
sphere containing  one  per  cent.,  and  that  he  himself  has  respired,  without  serious 
symptoms  ensuing,  air  which  contained  three  per  cent.     There  can  be  no  doubt, 
however,  that  the  continued  inhalation  of  air  thus  contaminated,  would  be  speedily 
fatal.     Sulphuretted  hydrogen. and  Hydro-sulphuret  of  ammonia  are  given-off 
from  most  forms  of  decaying  animal  and  vegetable  matter;  and  it  is  undoubtedly 
to  the  accumulation  of  these  gases,  that  the  fatal  results  which  sometimes  ensue 
from  entering  sewers  are  to  be  chiefly  attributed.  —  Carburetted  hydrogen  is  an- 
other gas  whose  effects  are  similar ;  but  a  larger  proportion  of  it  is  required  to 
destroy  life. — Carbonic  acid  gas,  also,  appears  to  be  absorbed  by  the  lungs,  when 
a  large  proportion  of  it  is  contained  in  the  atmosphere.     The  accumulation  of 

1  "  Casper's  Wochenschrift,"  1849,  band  15. 

a  "  Prize  Essay  on  Cutaneous  Absorption,"  p.  55. 


EXHALATION   AND   ABSORPTION   THROUGH    THE    LUNGS.  313 

this  gas  in  the  blood,  when  the  respired  air  is  charged  with  it  even  to  a  moderate 
amount,  might  be  attributed  to  the  impediment  thus  offered  to  its  ordinary  exha- 
lation (§  313)  :  but  the  following  experiment  appears  to  prove  that  it  may  be 
actually  absorbed  into  the  blood,  and  that  it  will  thus  exert  a  really-poisonous 
influence,  and  not  merely  produce  an  asphyxiating  effect.  It  was  found  by 
Rolando,  that  the  air-tube  of  one  lung  of  the  land-tortoise  may  be  tied,  without 
apparently  doing  any  material  injury  to  the  animal,  as  the  respiration  performed 
by  the  other  is  sufficient  to  maintain  life  for  some  time ;  but,  having  contrived  to 
make  a  tortoise  inhale  carbonic  acid  by  one  lung,  whilst  it  breathed  air  by  the 
other,  he  found  that  the  animal  died  in  a  few  hours.1  —  Cyanogen  is  another  gas 
which  has  an  actively-poisonous  influence  upon  animals,  when  absorbed  into  the 
lungs ;  its  agency,  also,  is  of  a  narcotic  character. 

325.  It  is  singular  that  the  effects  of  the  respiration  of  pure  Oxygen  should 
not  be  dissimilar.  At  first,  the  rapidity  of  the  pulse  and  the  number  of  the 
respirations  are  increased,  and  the  animal  appears  to  suffer  little  or  no  inconve- 
nience for  an  hour ;  but  symptoms  of  coma  then  gradually  develope  themselves, 
and  death  ensues  in  six,  ten,  or  twelve  hours.  If  the  animals  be  removed  into 
the  air  before  the  insensibility  is  complete,  they  quickly  recover.  When  the  body 
is  examined,  the  heart  is  seen  beating  strongly,  while  the  diaphragm  is  motion- 
less ;  the  whole  blood  in  the  veins,  as  well  as  in  the  arteries,  is  of  a  bright  scarlet 
colour ;  and  several  of  the  membranous  surfaces  have  the  same  tint.  The  blood 
is  observed  to  coagulate  with  remarkable  rapidity  ;  and  it  is  to  the  alteration  in 
its  properties,  occasioned  by  hyper-arterialization  (§  180),  and  indicated  by  this 
condition,  that  we  are  probably  to  attribute  the  fatal  result.  There  can  be  no 
doubt  that  in  this  instance,  an  undue  amount  of  oxygen  is  absorbed ;  and  it  does 
not  seem  unlikely  that  one  cause  of  the  fatal  result,  is  a  stagnation  of  the  blood 
in  the  systemic  capillaries,  consequent  upon  the  want  of  sufficient  change  in  its 
passage  through  them  (§  275). — When  Nitrogen  or  Hydrogen  is  breathed  for 
any  length  of  time,  death  results  from  the  deprivation  of  Oxygen,  rather  than 
from  any  deleterious  influence  which  these  gases  themselves  exert.  —  Death  is 
also  caused  by  the  inhalation  of  several  gases  of  an  irritant  character,  such  as 
Sulphurous,  Nitrous,  and  Muriatic  acids ;  but  it  is  doubtful  how  far  they  are 
absorbed,  or  how  far  their  injurious  effects  are  due  to  the  abnormal  action  which 
they  excite  in  the  lining  membrane  of  the  air-cells  and  tubes.  —  It  cannot  be 
doubted,  that  Miasmata  and  other  morbific  agents  diffused  through  the  atmo- 
sphere, are  more  readily  introduced  into  the  system  through  the  pulmonary  sur-, 
face  than  by  any  other;  and  our  aim  should  therefore  be  directed  to  the  discovery 
of  some  counteracting  agents,  which  can  be  introduced  in  the  same  manner.  The 
Pulmonary  surface  affords  a  most  advantageous  channel  for  the  introduction  of 
certain  medicines  that  can  be  raised  in  vapour,  when  it  is  desired  to  affect  the 
system  with  them  speedily  and  powerfully;  such  is  pre-eminently  the  case  with 
those  Anaesthetic  agents,  ether  and  chloroform,  whose  introduction  into  the  various 
departments  of  Medical  and  Surgical  practice  constitutes  a  most  important  era 
in  the  history  of  the  healing  art;  also  with  Mercury,2  Iodine,  Tobacco,  Stramo- 
nium, &c. 

1  The  fatal  result  of  breathing  the  fumes  of  charcoal  is,  therefore,  not  simple  Asphyxia, 
such  as  would  result  from  breathing  hydrogen  or  nitrogen.  —  Other  volatile  products  are 
set-free  in  the  combustion  of  charcoal,  besides  carbonic  acid.     Mr.  Coathupe  (loc.  cit.) 
states  these  to  be  Carbonate,  Muriate,  and  Sulphate  of  Ammonia,  Carbonic  Oxide,  Oxygen, 
Nitrogen,  Watery  vapour,  and  Empyreumatic  Oil :  to  these,  Sulphurous  acid  may  appear 
to  be  properly  added. 

2  The  beneficial  results  of  the  introduction  of  Mercury  by  inhalation,  are  strikingly  set 
forth  in  Mr.  Langston  Parker's  Essay  on  "  The  Treatment  of  Secondary,  Constitutional, 
and  Confirmed  Syphilis." — Am.  Ed. 


314  OF   RESPIRATION. 


3. — Effects  of  Suspension  or  Deficiency  of  Respiration. 

826.  We  have  now  to  consider  the  results  of  the  cessation  of  the  Respiratory 
function,  and  the  consequent  retention  of  Carbonic  Acid  in  the  blood.  If  this  be 
sufficiently  prolonged,  a  condition  ensues,  to  which  the  name  of  Asphyxia  has 
been  given ;  the  essential  character  of  which  is  the  cessation  of  muscular  move- 
ment, and  shortly  afterwards  of  the  Circulation;  with  an  accumulation  of  blood 
in  the  venous  system.  The  time  which  is  necessary  for  life  to  be  destroyed  by 
Asphyxia  varies  much,  not  only  in  different  animals,  but  in  different  states  of  the 
same.  Thus,  warm-blooded  animals  are  much  sooner  asphyxiated  than  Reptiles 
or  Invertebrata ;  on  the  other  hand,  a  hybernating  Mammal  supports  life  for 
many  months,  with  a  respiration  sufficiently  low  to  produce  speedily  asphyxia  if 
it  were  in  a  state  of  activity.  And  among  Mammalia  and  Birds,  there  are  many 
species  which  are  adapted,  by  peculiarities  of  conformation,  to  sustain  a  depriva- 
tion of  air  for  much  more  than  the  average  period.1  Excluding  these,  it  may  be 
stated  as  a  general  fact,  that,  if  a  warm-blooded  animal  in  a  state  of  activity  be 
deprived  of  respiratory  power,  its  muscular  movements  (with  the  exception  of  the 
contraction  of  the  heart)  will  cease  within  five  minutes,  often  within  three ;  and 
that  the  circulation  generally  fails  within  ten  minutes. — Many  persons,  however, 
are  capable  of  sustaining  a  deprivation  of  air  for  two,  three,  or  even  four  minutes,2 
without  insensibility  or  any  other  injury ;  but  this  power,  which  seems  possessed 
to  the  greatest  degree  by  the  divers  of  Ceylon,  can  only  be  acquired  by  habit. 
The  period  during  which  remedial  means  may  be  successful  in  restoring  the 
activity  of  the  vital  and  animal  functions,  is  not,  however,  restricted  to  this. 
There  is  one  well-authenticated  case,  in  which  recovery  took  place  after  a  con- 
tinuous submersion  of  fifteen  minutes,3  and  many  others  are  on  record,  of  the 
revival  of  drowned  persons  after  an  interval  of  half  an  hour,  or  even  more;  but 
there  is  not  the  same  certainty  in  regard  to  these,  that  the  individuals  may  not 
have  occasionally  risen  to  the  surface  and  taken  breath  there.  It  is  not  impro- 
bable, however,  that  in  some  of  these  cases  a  state  of  Syncope  had  come  on  at  the 
moment  of  immersion,  through  the  influence  of  fear  or  other  mental  emotion, 
concussion  of  the  brain,  &c. ;  so  that,  when  the  circulation  was  thus  enfeebled, 

1  Thus,  the  Cetacea  contain  far  more  blood  in  their  vessels,  than  do  any  other  Mam- 
malia ;  and  these  vessels  are  so  arranged,  that  both  arteries  and  veins  are  in  connection 
with  large  reservoirs  or  diverticula.     The  reservoirs  belonging  to  the  former  are  usually 
full ;  but  when  the  Whale  remains  long  under  water,  the  blood  which  they  contain  is  gra- 
dually introduced  into  the  circulation,  and,  after  becoming  venous,  accumulates  in  the 
reservoirs  connected  with  the  venous  system.     By  means  of  this  provision,  the  Whale  can 
remain  under  water  for  more  than  an  hour. 

2  Dr.  Hutchinson  states  that  any  man  of  ordinary  '  vital  capacity'  can  pass  two  minutes 
without  breathing,  if  he  first  makes  five  or  six  forcible  inspirations  and  expirations,  so  as 
to  cleanse  the  lungs  of  the  old  air,  and  then  fills  his  chest  as  completely  as  he  can.     "  For 
the  first  15  seconds,  a  giddiness  will  be  experienced ;  but  when  this  leaves  us,  we  do  not 
feel  the  slightest  inconvenience  for  want  of  air.     (See  "  Cyclop,  of  Anat.  and  Phys.," 
vol.  iv.  p.  1066.) 

*  The  following  are  the  facts  of  this  case,  as  narrated  by  Marc  ("Manuel  d'Autopsie 
Cadaverique  Me'dico-Le'gale,"  p.  165)  on  the  authority  of  Prater. — A  woman  convicted  of 
infanticide  was  condemned  to  die  by  drowning.  This  punishment  was  formerly  inflicted  in 
Germany  according  to  the  now  obsolete  Caroline  law,  the  culprit  being  inclosed  in  a  sack 
with  a  cock  and  a  cat,  and  sunk  to  the  bottom  of  the  water.  In  this  instance,  the  woman, 
after  having  been  submerged  for  a  quarter  of  an  hour,  was  drawn  up,  and  spontaneously 
recovered  her  senses.  She  stated  that  she  had  become  insensible  at  the  moment  of  her 
submersion ;  a  circumstance  which  adds  considerable  weight  to  the  supposition,  based 
upon  the  post-mortem  appearances  in  many  cases  of  drowning,  that  death  often  takes  place 
as  much  by  Syncope  (or  primary  failure  of  the  heart's  action,  consequent  upon  sudden  and 
violent  emotion,  or  upon  physical  shock)  as  by  Asphyxia.  If  the  reality  of  this  state  of 
Syncopal  Asphyxia  be  admitted,  there  does  not  seem  any  adequate  reason  for  limiting  the 
possible  persistence  of  vitality  in  a  submerged  body,  even  to  half  an  hour ;  especially  if 
the  temperature  of  the  water  be  such  as  not  to  cause  any  rapid  abstraction  of  its  heat. 


EFFECTS    OF    SUSPENSION    OR   DEFICIENCY    OF    RESPIRATION.         315 

the  deprivation  of  air  would  not  have  the  same  injurious  effect,  as  when  this 
function  was  in  full  activity.  The  case  would  then  closely  resemble  that  of  a 
hybernating  animal ;  for  in  both  instances  the  being  might  be  said  to  live  very 
slowly,  and  would  therefore  not  require  the  usual  amount  of  respiration.  The 
condition  of  the  still-born  infant  is  in  some  respects  the  same ;  and  re-animation 
has  been  successfully  attempted,  when  nearly  half  an  hour  had  intervened  between 
birth  and  the  employment  of  resuscitating  means,  and  when  probably  a  much 
longer  time  had  elapsed  from  the  period  of  the  suspension  of  the  circulation. 

327.  It  has  now  been  sufficiently  proved,  both  by  experiment  and  by  patholo- 
gical observation,  that  the  first  effect  of  the  non-arterialization  of  the  blood  in  the 
uings,  is  the  retardation  of  the  fluid  in  their  capillaries ;  of  which  the  accumula- 
tion in  the  venous  system,  and  the  deficient  supply  to  the  arterial,  are  the  neces- 
sary consequences.  It  is  some  time,  however,  before  a  complete  stagnation  takes 
place  from  this  cause ;  since,  as  long  as  the  proportion  of  oxygen  which  remains 
in  the  air  in  the  lungs  is  considerable,  and  that  of  the  carbonic  acid  is  small,  so 
long  will  some  imperfectly-arterialized  blood  finds  its  way  back  to  the  heart,  and 
be  transmitted  to  the  system.  This  blood  exerts  a  depressing  influence  upon  the 
nervous  centres,  which  is  aided  by  the  diminution  that  gradually  takes  place  in 
the  quantity  of  blood  propelled  to  them ;  and  thus  the  powers  of  the  Sensorial 
centres  are  suspended,  so  that  the  individual  becomes  unconscious  of  external 
impressions ;  whilst  the  activity  of  the  Medulla  Oblongata  also  becomes  dimi- 
nished, so  that  the  respiratory  movements  are  enfeebled.  The  progressive  ex- 
haustion of  the  oxygen  of  the  air  in  the  lungs,  and  the  accumulation  of  carbonic 
acid  in  the  blood,  increase  the  obstruction  in  the  pulmonary  capillaries ;  less  and 
less  blood  is  delivered  to  the  systemic  arteries,  and  what  is  thus  transmitted 
becomes  more  and  more  venous;  the  nervous  centres  are  now  completely  para- 
lyzed, and  the  respiratory  movements  cease  j  and  the  deficient  supply  of  blood, 
with  the  depravation  of  its  quality,  act  injuriously  upon  the  muscular  system  also, 
and  especially  weaken  the  contractility  of  the  heart.  In  this  enfeebled  state,  the 
final  cessation  of  its  movements  seems  attributable  to  two  distinct  causes,  acting 
on  the  two  sides  respectively ;  for  on  the  right  side  it  is  the  result  of  the  over- 
distension  of  the  walls  of  the  ventricle,  owing  to  the  accumulation  of  venous 
blood ;  and  on  the  left  to  deficiency  of  the  stimulus  necessary  to  excite  the  move- 
ment, which  is  no  longer  sustained  by  its  spontaneous  motility  (§  242).  The 
heart's  contractility  is  not  finally  lost,  however,  nearly  as  soon  as  its  movements 
sease;  for  the  action  of  the  right  ventricle  may  be  renewed,  for  some  time  after 
it  has  stopped,  by  withdrawing  a  portion  of  its  contents, — either  through  the  pul- 
monary artery,  their  natural  channel, — or,  more  directly,  by  an  opening  made  in 
its  own  parietes,  in  the  auricle,  or  in  the  jugular  vein  (§  247).  On  the  other 
hand,  the  left  ventricle  may  be  again  set  in  action,  by  renewing  its  appropriate 
stimulus  of  arterial  blood.  Hence,  if  the  stoppage  of  the  circulation  have  not 
been  of  too  long  continuance,  it  may  be  renewed  by  artificial  respiration;  for  the 
replacement  of  the  carbonic  acid  by  oxygen  in  the  air-cells  of  the  lungs,  restores 
the  circulation  through  the  pulmonary  capillaries ;  and  thus  at  the  same  time 
relieves  the  distension  of  the  right  ventricle,  and  conveys  to  the  left  the  due 
stimulus  to  its  actions. — Of  the  mode  in  which  the  Pulmonary  circulation  is  thus 
stagnated  by  the  want  of  oxygen,  and  renewed  by  its  ingress  into  the  lungs,  no 
other  consistent  explanation  can  be  given,  than  that  which  is  based  on  the  doc- 
trine already  laid  down  in  regard  to  the  capillary  circulation  in  general  (§  275)  ; 
namely  that  the  performance  of  the  normal  reaction  between  the  blood  and  the 
surrounding  medium  (whether  this  be  air,  water,  or  solid  organized  tissues)  is  a 
condition  necessary  to  the  regular  movement  of  the  blood  through  the  extreme 
vessels.  That  no  mechanical  impediment  to  its  passage  is  created  (as  some  have 
maintained)  by  the  want  of  distension  of  the  lungs,  has  been  fully  proved  by  the 
experiments  of  Dr.  J.  Reid  on  the  induction  of  Asphyxia  by  the  respiration  of 
azote.  And  that  a  contraction  of  the  small  arteries  and  capillaries,  under  the 


316  OF   RESPIRATION. 

stimulus  of  venous  blood  cannot  be  legitimately  assigned  as  the  cause  of  the 
obstruction,  is  evident  from  the  consideration  brought  to  bear  upon  it  by  the  same 
excellent  experimenter;  namely,  the  suddenness  with  which  the  flow  is  renewed 
on  the  admission  of  oxygen,  as  contrasted  with  the  slowness  with  which  arteries 
dilate  after  the  removal  of  the  cause  of  their  contraction  (§  256). ' 

328.  It  cannot  be  necessary  here  to  dwell  upon  the  fact,  that  by  the  repeated 
passage  of  the  same  air  through  the  lungs,  it  may,  though  originally  pure  and 
wholesome,  be  so  strongly  impregnated  with  carbonic  acid,  and  may  lose  so  much 
of  its  oxygen,  as  to  be  rendered  utterly  unfit  for  the  continued  maintenance  of 
the  aerating  process;  so  that  the  individual  who  continues  to  respire  it,  shortly 
becomes  asphyxiated.     There  are  several  well-known  cases,  in  which  the  speedy 
death  of  a  number  of  persons  confined  together,  has  resulted  from  neglect  of  the 
most  ordinary  precautions  for  supplying  them  with  air.     That  of  the  "  Black 
Hole  of  Calcutta,"  which  occurred  in  1756,  has  acquired  an  unenviable  pre- 
eminence, owing  to  the  very  large  proportion  of  the  prisoners, — 1*23  out  of  146, 
— who  die<J  during  one  night's  confinement  in  a  room,  18  feet  square,  only  pro- 
vided with  two  small  windows;  and  it  is  a  remarkable  confirmation  of  the  views 
formerly  stated  (§  226),  and  presently  to  be  again  adverted  to,  that  of  the  23  who 
were  found  alive  in  the  morning,  many  were  subsequently  cut  off  by  '  putrid 
fever.'     Such  catastrophes  have  occurred  even  in  this  country,  from  time  to  time, 
though  usually  upon  a  smaller  scale ;  there  has  happened  one  at  no  distant  date, 
however,  which  rivalled  it  in  magnitude.    On  the  night  of  the  first  of  December, 
1848,  the  deck-passengers  on  board  the  Irish  steamer  Londonderry  were  ordered 
below  by  the  Captain,  on  account  of  the  stormy  character  of  the  weather ;  and 
although  they  were  crowded  into  a  cabin  far  too  small  for  their  accommodation, 
the  hatches  were  closed  down  upon  them.     The  consequence  of  this  was,  that 
out  of  150  individuals,  no  fewer  than  70  were  suffocated  before  the  morning. 

329.  It  cannot  be  too  strongly  impressed  upon  the  Medical  practitioner,  how- 
ever, and  through  him  upon  the  Public  in  general,  that  the  continued  respiration 
of  an  atmosphere  charged  in  a  far  inferior  degree  with  the  exhalations  from  the 
Lungs  and  Skin,  is  among  the  most  potent  of  all  the  '  predisposing  causes'  of 
disease,  and  especially  of  those  zymotic  diseases  whose  propagation  seems  to 
depend  upon  the  presence  of  fermentible  matter  in  the  blood.     That  such  is 
really  the  fact,  will  appear  from  evidence  to  be  presently  referred  to ;  and  it  is 
not  difficult  to  find  a  complete  and  satisfactory  explanation  of  it.     For,  as  the 
presence  of  even  a  small  per  centage  of  carbonic  acid  in  the  respired  air,  is  suffi- 
cient to  cause  a  serious  diminution  in  the  amount  of  carbonic  acid  thrown  off  and 
of  oxygen  absorbed  (§  313),  it  follows  that  those  oxidating  processes  which  min- 
ister to  the  elimination  of  effete  matter  from  the  system,  must  be  imperfectly  per- 
formed, and  that  an  accumulation  of  substances  tending  to  putrescence  must 
take  place  in  the  blood.     Hence  there  will  propably  be  a  considerable  increase  in 
the  amount  of  such  matters  in  the  pulmonary  and  cutaneous  exhalation;  and  the 
unrenewed  air  will  become  charged,  not  only  with  carbonic  acid,  but  also  with 
organic  matter  in  a  state  of  decomposition,  and  will  thus  favour  the  accumulation 
of  both  these  morbific  substances  in  the  blood,  instead  of  effecting  that  constant 
and  complete  removal  of  them,  which  it  is  one  of  the  chief  ends  of  the  respiratory 
process  to  accomplish. — It  has  been  customary  to  consider  the  consequences  of 
imperfect  respiration,  as  being  exerted  merely  in  promoting  an  accumulation  of 
carbonic  acid  in  the  system,  and  in  thus  depressing  the  vital  powers,  and  ren- 
dering it  prone  to  the  attacks  of  disease.     But  the  deficiency  of  oxygenation,  and 

1  For  a  fuller  discussion  of  the  pathology  of  Asphyxia,  see  the  "  Cyclop,  of  Anat.  an  1 
Phys.,"  art.  'Asphyxia,'  by  Prof.  Alison;  the  "Library  of  Practical  Medicine,"  vol.  iii. 
art.  'Asphyxia,'  by  the  Author;  the  Experimental  Essay  by  Dr.  J.  Reid,  'On  the  Order 
of  Succession  in  which  the  Vital  Actions  are  arrested  in  Asphyxia,'  in  the  "Edinb.  Med. 
and  Surg.  Journ."  1841,  and  in  his  "Anat.,  Physiol.,  and  Pathol.  Researches;"  and  the 
Experimental  Inquiry  by  Mr.  Erichsen,  in  the  "Edinb.  Med.  and  Surg.  Journ.,"  1845. 


EFFECTS    OF   RESPIRATION    OF    A   VITIATED    ATMOSPHERE.  317 

the  consequent  increase  of  putrescent  matter  in  the  body,  must  be  admitted  as  at 
least  a  concurrent  agency;  and  when  it  is  borne  in  mind  that  the  atmosphere  in 
which  a  number  of  persons  have  been  confined  for  some  time,  becomes  actually 
offensive  to  the  smell  in  consequence  of  the  accumulation  of  such  exhalations, 
and  that  (as  will  presently  appear)  this  accumulation  exerts  precisely  the  same 
influence  upon  the  spread  of  zymotic  disease,  as  that  which  is  afforded  by  the  dif- 
fusion of  a  sewer-atmosphere  through  the  respired  air,  it  scarcely  admits  of  rea- 
sonable doubt,  that  the  pernicious  effect  of  over-crowding  is  exerted  yet  more 
through  its  tendency  to  promote  putrescence  in  the  system,  than  through  the 
obstruction  it  creates  to  the  due  elimination  of  carbonic  acid  from  the  blood. 
For  it  is  to  be  remembered,  that  whilst  the  complete  oxidation  of  the  effete  matters 
will  carry  them  off  by  the  lungs  in  the  form  of  carbonic  acid  and  water,  leaving 
urea  and  other  highly-azotized  products  to  pass  off  by  the  kidneys,  an  imperfect 
oxidation  will  only  convert  them  into  those  peculiarly  offensive  products  which 
characterize  the  faecal  excretion  (§  118). * 

330.  Of  the  remarkable  tendency  of  the  Respiration  of  an  atmosphere  charged 
with  the  emanations  of  the  Human  body,  to  favour  the  spread  of  Zymotic 
diseases,  a  few  characteristic  examples  will  now  be  given.  —  All  those  who  have 
had  the  widest  opportunities  of  studying  the  conditions  which  predispose  to  the 
invasion  of  Cholera,  are  agreed  that  overcrowding  is  among  the  most  potent  of 
these  ;  and  from  the  numerous  cases  in  which  this  was  most  evident,  contained  in 
the  "  Report  of  the  General  Board  of  Health  "  on  the  epidemic  of  1848-9,  the 
two  following  may  be  selected.  —  In  the  autumn  of  1849,  a  sudden  and  violent 
outbreak  of  Cholera  occurred  in  the  Workhouse  of  the  town  of  Taunton;  no 
case  of  cholera  having  either  previously  existed,  or  subsequently  presenting  itself, 
among  the  inhabitants  of  the  town  in  general,  although  diarrhoea  was  prevalent 
to  a  considerable  extent.  The  building  was  altogether  badly  constructed,  and 
the  ventilation  deficient ;  but  this  was  especially  the  case  with  the  school-rooms, 
there  being  only  about  68  cubic  feet  of  air  for  each  girl,  and  even  less  for  the 
boys.  On  Nov.  3,  one  of  the  inmates  was  attacked  with  the  disease  ;  in  ten 
minutes  from  the  time  of  the  seizure,  the  sufferer  passed  into  a  state  of  hopeless 
collapse ;  within  the  space  of  forty-eight  hours  from  the  first  attack,  42  cases  and 
19  deaths  took  place;  and  in  the  course  of  one  week,  60  of  the  inmates,  or 
nearly  22  per  cent,  of  the  entire  number,  were  carried-off,  while  almost  every  one 
of  the  survivors  suffered  more  or  less  severely  from  cholera  or  diarrhoea.  Among 
the  fatal  cases  were  those  of  25  girls  and  9  boys;  and  the  comparative  immunity 
of  the  latter,  notwithstanding  the  yet  more  limited  dimensions  of  their  school- 
rooms, affords  a  remarkable  confirmation  of  the  general  doctrine  here  advanced ; 
for  we  learn  that,  although  "  good  and  obedient  in  other  respects,  they  could  not 
be  kept  from  breaking  the  windows,"  so  that  many  of  them  probably  owed  their 
lives  to  the  better  ventilation  thus  established.  Now  in  the  Gaol  of  the  same 
town,  in  which  every  prisoner  is  allowed  from  819  to  935  cubic  feet  of  air,  and 
this  is  continually  being  renewed  by  an  eflicient  system  of  ventilation,  there  was 
not  the  slightest  indication  of  the  epidemic  influence  (Op.  cit.,  pp.  37  and  71). 
— The  other  case  to  be  here  cited,  is  that  of  Millbank  Prison,  in  which  the  good 
effects  of  the  diminution  of  previous  overcrowding  were  extremely  marked.  In 
the  month  of  July,  1849,  when  the  epidemic  was  becoming  general  and  severe 
in  the  Metropolis  (especially  in  those  low  ill-drained  parts  on  both  sides  of  the 
river,  in  the  midst  of  which  this  prison  is  situated),  the  number  of  male  prisoners 
was  reduced,  by  the  transfer  of  a  large  proportion  of  them  to  Shorncliff  barracks, 

1  It  is  a  remarkable  confirmation  of  Prof.  Liebig's  analogy  between  the  imperfect  oxida- 
tion of  effete  matters  within  the  body,  and  that  combustion  in  a  lamp  or  furnace  insuffi 
ciently  supplied  with  air  which  causes  a  deposit  of  soot  and  various  empyreumatic  pro- 
ducts, that  a  set  of  acids  have  been  found  by  Stadeler  in  the  urine  of  the  cow,  bearing  a 
remarkable  analogy  to  well-known  products  of  destructive  distillation,  and  one  of  them 
actually  identical  with  the  carbolic  acid  previously  known  as  one  of  the  ingredients  of  smoke 
—See  Prof.  Gregory's  "  Handbook  of  Organic  Chemistry,"  p.  450. 


818 


OF    RESPIRATION. 


from  1039  to  402  ;  the  number  of  female  prisoners,  on  the  other  hand,  not  only 
underwent  no  reduction,  but  was  augmented  from  120  to  131.  Now  the  Cholera 
mortality  of  London  generally,  which  was  0-9  per  1000  in  June  and  July,  in- 
creased to  4-5  per  1000  in  August  and  September;  and  the  mortality  among  the 
female  prisoners  underwent  a  similar  increase,  from  8-3  to  534  per  1000;  but 
the  mortality  among  the  male  prisoners  exhibited  the  extraordinary  diminution, 
from  23-1  per  1000,  which  was  its  rate  during  June  and  July  when  the  prison 
was  crowded,  to  9 -9  per  1000,  which  was  its  rate  during  August  and  September 
after  the  reduction  had  taken  place  (Op.  cit.,  App.  B.,  p.  67).  It  is  scarcely 
possible  to  imagine  a  more  probative  case  than  this ;  since  it  shows,  in  the  first 
place,  the  marked  influence  of  the  crowded  state  of  the  prison  upon  the  fatality 
of  the  disease, — secondly,  the  diminution  of  mortality  among  the  male  prisoners, 
consequent  upon  the  relief  of  the  overcrowding,  notwithstanding  the  quintupling 
of  the  general  mortality  of  the  Metropolis  during  the  same  period, — and  thirdly, 
the  yet  greater  increase  of  mortality  among  the  female  prisoners,  which  proved 
that  the  diminution  among  the  males  could  not  be  attributed  to  any  recession  of 
the  epidemic  influence  from  the  locality. 

331.  The  cholera-experience  of  the  Indian  army  is  fertile  in  examples  of  the 
same  kind,  whose  peculiar  character  makes  them  even  more  remarkable.  It  is 
to  be  remembered  that  the  normal  amount  of  Respiration  is  much  lower  in  a  hot, 
than  in  a  temperate  climate  (§§  156,  316  l);  consequently,  any  deficiency  of 
oxygenation  will  tend  in  a  yet  higher  degree  to  promote  the  accumulation  of 
putrescent  matter  in  the  system,  and  this  especially  when  there  has  been  any 
unusual  source  of  '  waste/  such  as  that  induced  by  excessive  muscular  exertion. 
—  The  circumstances  attendant  upon  the  outbreak  of  Cholera,  in  1846,  at  Kur- 
rachee  in  Scinde,  in  which  ten  per  cent,  of  an  army  of  6380  men  were  carried- 
off,  place  the  influence  of  these  conditions  in  a  very  striking  point  of  view.  In 
order  that  the  comparison  may  be  fairly  made,  the  data  specified  in  the  following 
Table  will  be  taken  only  from  European  regiments,  similar  to  each  other  in  diet, 
clothing,  regimen,  habits,  and  every  other  conceivable  particular,  save  such  as 
will  be  mentioned  : — 


Designation. 

Strength. 

Deaths. 

Deaths 
per  1000. 

Exposure 
at  Drill,  &c. 

Provision 
for  Respiration. 

Previous 
exertion. 

Officers'  Ladies.. 

42 

0 

0 

Nil 

Good 

Nil. 

Officers  

200 

3 

15 

Ordinary 

Horse  Brigade... 

135 

5 

37 

Ordinary 

Good 

Moderate. 

60th  Rifles  

980 

75 

76  5 

Ordinary 

Bad 

Nil 

Artillery  

375 

37 

96-6 

Good 

Bombay  Fusiliers 

764 

83 

108-6 

Ordinary 

Very  bad 

Nil. 

Soldiers'  Wives... 
Do.  of  86th  Regt. 

159 

23 

144-6 
166-6 

Nil 
Nil 

Mostly  very  bad 
Very  bad 

Partly  severe 
Very  severe. 

86th  Regiment... 

1091 

238 

218 

Ordinary 

Very  bad 

Very  severe. 

3746 

464 

124 

Now  most  of  the  Officers,  and  all  the  Ladies,  were  quartered  in  well-ventilated 
apartments ;  and  the  only  predisposing  cause  from  which  the  former  could  be 
considered  as  liable  to  suffer,  was  the  exposure,  in  common  with  the  soldiers,  to 
the  burning  heat  during  the  hours  of  drill.  Of  the  9  officers  attacked  with 
cholera,  of  whom  3  died  (only  one  of  the  fatal  cases  being  an  uncomplicated 
one),  4  belonged  to  the  Bombay  Fusiliers,  and  had  been  living  (like  their  men) 
in  tents.  The  Horse  Brigade  were  lodged  in  good  barracks,  but  had  recently 
come  off  a  march  of  1000  miles;  being  mounted,  however,  they  must  have 
suffered  comparatively  little  fatigue  from  this.  The  60th  Rifles  were  quartered 
in  barracks;  but  the  ventilation  of  these  was  very  imperfect,  and  the  men  were 


EFFECTS    OF   RESPIRATION    OF   A    VITIATED    ATMOSPHERE.  319 

tnuch  crowded.  The  battalions  of  Artillery  were  quartered  in  good  barracks ; 
but  three  out  of  the  four  had  recently  made  the  march  of  1000  miles  on  foot. 
The  Bombay  Fusiliers  were  quartered  in  tents,  whose  accommodation  was  so 
limited,  that  10  or  12  men  were  cooped-up  in  a  space  14  feet  square,  with  the 
thermometer  ranging  from  96°  to  100°,  and  without  any  adequate  provision  for 
ventilation.  The  86th  Regiment  was  quartered  in  precisely  the  same  manner; 
and  had  recently  made  the  march  of  1000  miles  under  very  unfavourable  cir- 
cumstances, besides  having  previously  suffered  from  the  debilitating  influence  of 
severe  service.  The  condition  of  the  Soldiers'  Wives  as  regards  their  accommo- 
dation would  be  the  same  as  that  of  their  husbands,  but  they  would  not  be  sub- 
jected to  the  fatigue  and  exposure  of  drill;  on  the  other  hand,  their  fatigue  and 
exposure  during  a  march  would  be  scarcely  inferior  to  that  of  the  men;  and  it 
was  among  the  women,  as  among  the  soldiers,  of  the  86th  Regiment,  that  the 
chief  mortality  occurred,  their  loss  having  been  1  in  6  or  166-6  per  1000.  — 
Thus  we  see  that  the  highest  rate  of  mortality  presents  itself,  where  the  three 
causes  were  in  concurrent  action ;  the  absence  of  mortality,  where  neither  of 
them  was  in  operation.  The  difference  between  the  mortality  of  the  Bombay 
Fusiliers  (108-6  per  1000)  and  that  of  the  86th  Regiment  (218  per  1000), 
which  were  under  precisely  the  same  conditions  as  regards  exposure  and  ventila- 
tion, shows  the  extraordinary  influence  of  previous  exertion  ;  but  that  this  would 
not  of  itself  account  for  the  high  rate  of  mortality  in  the  86th,  is  shown  by  the 
smaller  proportion  of  deaths  in  the  Artillery ;  the  influence  of  the  same  march 
upon  three  out  of  its  four  battalions,  having  been  in  a  great  degree  kept-down 
by  the  adequate  provision  for  their  respiration,  so  that  their  mortality  was  less 
than  that  of  the  Bombay  Fusiliers,  who  had  not  suffered  from  previous  exertion, 
but  were  over-crowded  in  ill-ventilated  tents.  —  It  is  scarcely  possible  to  imagine 
any  more  satisfactory  proof  of  the  prevent ibility  of  a  large  part  of  this  terrible 
mortality,  than  is  afforded  by  the  analysis  of  this  case ; l  but  if  any  confirmation 
be  required,  it  is  afforded  by  the  case  of  Bellary,  a  fortress  about  250  miles  north- 
west of  Madras.  Although  by  no  means  unhealthily  situated,  this  station  was 
not  free  from  Cholera  for  a  single  year  between  1818  and  1844;  and  violent  out- 
breaks to'ok  place  occasionally,  such  as  that  of  1839,  in  which  the  39th  Regi- 
ment was  reduced  in  five  months  from  735  men  to  645,  the  number  of  deaths 
being  90,  or  122£  per  1000.  The  barrack-accommodation  in  this  fort  was  ex- 
tremely insufficient  for  the  garrison  regularly  quartered  in  it ;  yet  small  as  it 
was,  it  was  occasionally  encroached-upon  still  further  by  the  introduction  of 
troops  upon  their  march ;  and  after  such  occasions  of  special  overcrowding,  a 
large  increase  in  the  mortality  almost  invariably  occurred.  But  since  the  barrack- 
accommodation  has  been  improved,  the  troops  quartered  at  Bellary  have  ceased 
to  suffer  from  Cholera  in  any  exceptional  degree,  and  the  ordinary  rate  of  mor- 
tality has  been  considerably  diminished. 

332.  The  only  condition  of  atmosphere  which  can  be  compared  with  that 
arising  from  overcrowding,  in  its  effect  upon  the  spread  of  Cholera,  is  that  pro- 
duced by  the  diffusion  of  the  effluvia  of  drains,  sewers,  slaughter-houses,  manure- 
manufactories,  &c.,  which  correspond  closely  in  their  nature  and  effects  with  the 
putrescent  emanations  from  the  living  human  body.  So  remarkably  has  the 
localization  of  the  disease  shown  itself  to  be  connected  with  this  condition,  that 
the  knowledge  of  the  existence  of  the  latter  makes  it  safe  to  predict  the  former; 
such  a  prediction  being  scarcely  ever  falsified  by  the  result.  —  As  a  characteristic 
illustration  of  the  operation  of  this  cause,  the  outbreak  of  Cholera  at  Albion 
Terrace,  Wandsworth-road,  in  1849,  may  be  specially  referred-to.  This  place 
consisted  of  17  houses,  having  the  appearance  of  commodious  middle-class  dwell- 
ings ;  the  population  does  not  seem  to  have  averaged  more  than  7  individuals 
per  house,  so  that  there  was  no  overcrowding;  yet  out  of  the  total  119  or  120, 

1  For  a  fuller  statement  of  it,  see  the  "Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  ii.   {..p 
81  -89. 


320  OF  .RESPIRATION. 

no  fewer  than  42  persons  were  attacked  with  cholera,  of  whom  30  (or  25  per  cent.) 
died.  It  was  not  difficult  to  account  for  this  fearful  result,  when  the  circumstan- 
ces of  the  case  were  inquired-into.  About  200  yards  in  the  rear  of  the  terrace 
was  an  open  sewer,  whose  effluvia  were  most  offensive  at  the  backs  of  these 
houses,  whenever  the  wind  wafted  them  in  that  direction;  and  the  drainage  of 
the  houses  themselves  was  so  bad,  that  a  stench  was  continually  perceived  to 
arise  from  different  parts  of  the  kitchen-floor,  and  more  especially  from  the  back- 
kitchen.  Moreover,  in  the  house  in  which  the  first  case  of  cholera  occurred, 
there  was  an  enormous  accumulation  of  most  offensive  rubbish,  exhaling  a  putrid 
effluvium.  And  there  was  also  reason  to  believe,  that  the  water  supplied  to  some 
of  the  houses  had  accidentally  become  contaminated  with  the  contents  of  a  sewer 
and  cess-pool.1 — The  accumulation  of  night-soil  and  other  rubbish  in  a  triangular 
space  of  about  three  acres  in  Witham,  a  suburb  of  Hull,  had  been  represented 
to  the  local  authorities  as  almost  certain  to  induce  a  severe  outbreak  of  cholera 
in  the  neighbourhood;  the  prediction  was  disregarded;  but  it  was  most  fearfully 
verified  by  the  occurrence  of  no  fewer  than  91  deaths  in  its  immediate  neighbour- 
hood.2— Numerous  examples  of  the  same  kind  might  be  cited;  but  the  following 
shows  the  efficacy  of  preventive  measures.  The  Coldbath-fields  House  of  Cor- 
rection, situated  in  the  neighbourhood  of  some  of  the  most  overcrowded  and  ill- 
drained  parts  of  the  metropolis,  had  suffered  severely  from  Cholera  in  the 
epidemic  of  1832-3 ;  for  out  of  1148  prisoners,  207  were  attacked  with  cholera, 
of  whom  45  died,  and  319  more  suffered  from  diarrhoea.  At  that  period,  how- 
ever, it  was  discovered  that  the  whole  drainage  of  the  prison  was  in  a  most  defec- 
tive state,  and  steps  were  taken  to  have  it  completely  and  effectually  renewed ;  at 
the  same  time  the  diet  was  somewhat  improved,  and  more  attention  was  paid  to 
temperature  and  ventilation.  In  the  epidemic  of  1848-9,  with  1100  prisoners, 
there  was  not  a  single  case  of  cholera  in  this  prison,  although  the  disease  wag 
raging  in  its  vicinity ;  and  the  cases  of  diarrhoea  were  few  in  number,  and  were 
mild  in  their  character.8 

333.  The  Cholera-experience  of  the  United  States  during  the  Epidemic  of 
1849-50,4  afforded  some  of  the  most  striking  examples  that  have  been  anywhere 
displayed,  both  of  the  dire  effects  of  neglect,  and  of  the  complete  efficacy  of  pre- 
ventive measures.  The  contrast  is  well  shown  in  the  manner  in  which  the 
epidemic  affected  the  town  of  Louisville,  in  Kentucky;  which  is  situated  by  the 
Ohio  river,  on  a  plateau  about  70  feet  above  low-water  mark,  composed  of  sand 
and  river-gravel,  intermingled  with  tenacious  clay,  and  reposing  on  a  friable 
shale.  This  compound  is  peculiarly  tenacious  of  moisture;  and  large  ponds 
formerly  existed,  in  the  midst  of  which  the  first  houses  were  built.  While  this 
state  of  things  continued,  Louisville  was  one  of  the  most  sickly  towns  in  the 
Mississippi  valley,  and  was  commonly  termed  "  the  graveyard  of  the  West." 
Intermittent  fever  was  a  regular  visitant;  and  epidemics  of  fever  of  other  types 
frequently  raged  with  great  severity.  Thus,  in  the  summer  of  1822,  after  a  hot 
rainy  season,  232  persons  died  of  bilious  fever  out  of  a  population  of  about 
5000 ;  in  a  family  consisting  of  20  persons  19  were  sick  at  one  time,  and  in 
some  families  every  individual  died.  At  this  period,  only  one  street  in  Louis- 
ville was  paved ;  and  within  its  limits  were  at  least  eight  ponds  of  greater  or 
less  dimensions,  most  of  which,  in  the  course  of  the  autumn,  were  dried-up, 
exposing  foul  bottoms  to  the  sun.  Previously  to  the  Cholera-epidemic  of 
1832-3,  its  condition  had  been  somewhat  improved ;  still  the  principal  part  of 
the  town  suffered  severely.  Much  more,  however,  has  been  subsequently  effected ; 
BO  that  from  being  reputed  one  of  the  most  unhealthy  towns  in  the  west,  Louis- 

1  "Report  of  the  General  Board  of  Health  on  the  Epidemic  Cholera  of  1848-9,"  p.  43. 

a  Op.  cit,  p.  45.  3  Op.  cit.,  App.  B,  p.  68. 

*  See  the  'Abstract  of  Report  by  James  Wynne,  M.  D.,  on  Epidemic  Cholera,  as  it  pre- 
vailed in  the  United  States  in  1849  and  1850;'  constituting  "  Appendix  c  to  the  Report 
*f  the  General  Board  of  Health  on  the  Epidemic  Cholera  of  1848-9." 


EFFECTS    OF   RESPIRATION    OF    A   VITIATED   ATMOSPHERE.  321 

ville  has  come  to  be  esteemed  one  of  the  most  healthy :  at  the  same  time  its 
population  has  increased  from  10,000  in  1830,  to  50,000  in  1850.  Entire 
squares  are  now  pointed  out,  which  occupy  the  beds  of  ponds  once  large  and 
deep  enough  to  float  a  steamboat.  Still  much  of  the  lower  part  of  the  city  is 
in  a  very  foul  condition ;  the  ground  on  which  it  is  built  being  saturated  with 
water  to  a  considerable  depth  after  heavy  rains,  and  being  also  the  receptacle  of 
the  filthy  washings  of  the  more  elevated  portion  ;  besides  having  many  nuisances 
of  its  own,  especially  accumulations  of  decaying  hemp-offal.  It  was  in  this  part 
that  Cholera  first  made  its  appearance  in  1849,  in  the  identical  square  in  which 
the  earliest  cases  had  appeared  in  1832;  and  to  this  part  it  was  almost  entirely 
restricted.  "  Those  places  in  Louisville"  says  the  Medical  Reporter,  lt  which 
bore  the  brunt  of  the  Cholera  in  1833,  and  which  have  been  improved  so  as  to 
be  dry,  clean,  and  airy,  have  been  as  free  from  Cholera  as  from  the  oriental 
plague.  But  those  places  in  this  city  which,  were  scourged  in  1833,  and 
which  remain  now  in  the  state  they  were  in  then,  have  been  scourged  again  in 
1849-50." 

334.  A  yet  more  remarkable  contrast  is  presented  by  the  comparative  expe- 
rience of  the  City  and  of  the  Almshouse  of  Baltimore.     Luring  the  spring  of 
1849,  when  from  the  prevalence  of  Cholera  in  the  great  towns  to  the  north,  it 
appeared  next  to  certain  that  the  epidemic  would  visit  Baltimore,  not  only  its 
public  authorities,  but  its  citizens  generally,  exerted  themselves  with  commenda- 
ble   zeal  to  ward-off  its  severity  by  active  measures  of  sanitary  purification. 
Although  in  many  respects  superior  to  the  average  of  large  towns,  Baltimore  was 
by  no  means  free  from  those  collections  of  filth  invariably  found  to  a  greater  or 
less  extent  among  the  most  degraded  portion  of  their  population ;  and  of  the 
evil  results  of  these,  the  constant  presence  of  typhoid  fever,  among  the  misera- 
ble coloured  inhabitants  of  its  worst  localities,  had  long  furnished  a  standing 
proof.     During  the  summer  months,  when  the  city  was  completely  surrounded 
by  the  Choleraic  atmosphere,  diarrhoea  and  kindred  affections  became  very  preva- 
lent in  Baltimore;  and  Dr.  Wynne  further  mentions,  as  of  universal  occurrence 
in  those  who  had  not  a  positive  attack  of  diarrhoea,  "  an  undefinable  sense  of 
oppression,  not  amounting  to  pain,  over  the  whole    region  of  the    abdomen, 
reminding  the  person  constantly  of  the  existence  of  such  a  part  of  the  body." 
This  state  of  things  impressed  the  Medical  authorities  with  the  belief  that  the 
Cholera-poison  was  brooding  over  the  town,  and  that  an  outbreak  might  be  con- 
tinually expected.     Yet  it  entirely  passed  away,  without  giving  rise  to  more  than 
four  attacks  of  genuine  Cholera;  two  of  these  being  in  the  persons  of  Germans, 
who  occupied  a  wretched  tenement  in  a  very  filthy  condition ;  the  third  case 
being  that  of  a  man,  whose  sleeping  apartment  looked-out  upon  an  alley  which 
had  been  suffered  to  remain  in  a  very  foul  state ;  whilst  the  fourth,  which  oc- 
curred in  the  largest  and  most  fashionable  hotel  in  the  city,  was  obviously  all 
imported    case. — Yet,  as  if  for    the  very  purpose  of  demonstrating    that   the 
immunity  which  the  City  itself  enjoyed,  was  entirely  due  to  the  sanitary  pre 
cautions  which  its  inhabitants  had  so  wisely  taken,  a  fearful  outbreak  of  Cholera 
took  place  in  the  Almshouse,  only  two  miles  out  of  town,  which  proved  fatal  to 
99  persons  out  of  a  population  of  632,  or  nearly  one  in  six;  and  it  was  only 
kept  within  this  limit,  by  the  promptness  with  which  the  sources  of  this  terrible 
mortality  were  removed  when  once  they  had  been  discovered. 

335.  The  circumstances  of  this  outbreak  were  so  peculiar,  as  to  need  a  some- 
what detailed  description. — The  main  building  of  the  Almshouse  was  originally 
the  country-seat  of  a  wealthy  citizen,  who  erected  a  costly  mansion  on  an  elevated 
site  which  he  had  specially  chosen  for  its  beauty  and  healthfullness;  it  had  sub- 
sequently been  much  enlarged,  for  the  accommodation  of  its  six  or  seven  hundred 
inmates;  but  it  still  remained  entirely  isolated,  being  surrounded  by  a  farm  of 
200  acres,  for  the  most  part  devoted  to  cultivation.     From  the  original  centre, 
two  principal  wings  extended  on  either  side,  one  for  the  male  and  the  other  for 

21 


322  OF    RESPIRATION. 

the  female  side,  forming  an  extensive  range  of  building:,  whose  front  had  a 
southern  aspect,  whilst  the  hack  looked  towards  the  north.  Behind  this  were 
other  wings  running  north  and  south,  with  various  offices,  spread  over  an  area 
of  about  4£  acres,  which  was  enclosed  by  a  wall.  Like  the  city  itself,  the  Alms- 
house  had  received  a  thorough  purification,  under  the  superintendence  of  the 
visiting  physician ;  whose  directions,  as  regarded  ventilation  and  internal  cleanli- 
ness, seem  to  have  been  strictly  complied  with.  Nevertheless  an  unequivocal 
case  of  Cholera  presented  itself  on  July  1st,  another  on  July  7th,  four  more 
during  the  ensuing  week,  and  on  July  14th  thirteen  of  the  inmates  were  attacked 
at  once.  All  the  patients  were  old  inhabitants  of  the  establishment,  and  had 
unequivocally  contacted  the  disease  on  the  spot;  but  although  fully  impressed 
with  the  conviction  that  some  special  cause  must  exist  for  this  rapidly-increasing 
mortality,  the  visiting  physician  did  not  succeed  in  detecting  it  until  the  19th, 
when  he  extended  his  survey,  for  the  first  time,  beyond  the  enclosure.  He  then 
discovered  that  the  whole  triangular  space  included  between  its  posterior  boun- 
dary-wall, and  a  ravine  which  approached  within  nine  feet  of  its  western  angle, 
but  which  was  separated  from  its  eastern  angle  by  an  interval  of  about  seventy 
feet,  was  one  putrid  and  pestilential  mass,  capable  of  generating,  under  the  ardent 
rays  of  a  midsummer  sun,  the  most  poisonous  emanations;  for  although  the  ravine 
was  admirably  adapted  to  carry-off  the  drainage  of  the  establishment,  this  had 
never  been  properly  conducted  into  it;  the  overflowings  of  cesspools,  pigsties, 
&c.,  having  been  allowed  to  spread  themselves  over  the  intervening  area,  which 
they  kept,  of  course,  in  a  state  of  constant  pollution,  superficially  concealed  by  a 
rank  weedy  vegetation.  Some  difficulty  was  experienced  in  procuring  men  to 
remove  this  nuisance,  so  that  it  remained  untouched  till  the  23rd.  The  pools  of 
filth  were  then  drained  by  trenches  into  the  ravine,  and  were  washed-out  by  a 
stream  of  fresh  water;  lime  was  spread  over  the  whole  surface;  and  this  again 
was  covered  with  a  thick  layer  of  earth.  The  men  employed  in  this  work  were 
attacked  with  Cholera,  but  recovered.  The  day  after  it  was  completed,  the  num- 
ber of  cases  in  the  Almshouse  suddenly  dropped  from  eleven  to  three;  and  within 
a  fortnight  more,  the  disease  had  entirely  disappeared. — But  this  is  by  no  means 
all.  The  attacks  of  Cholera  were  far  from  being  uniformly  distributed  through 
the  building,  but  were  almost  exclusively  restricted  to  those  parts  of  it  which 
were  directly  exposed  to  the  emanations  conveyed  from  this  pestilential  spot,  by 
the  northerly  wind  which  blew  steadily  during  the  whole  time  of  the  prevalence 
of  the  disease.  Thus,  in  the  centre  building,  the  Manager,  who  slept  in  a  room 
looking  to  the  north,  was  attacked,  but  recovered;  among  his  family,  whose  rooms 
looked  to  the  south,  no  case  of  the  disease  occurred.  Four  medical  students  who 
occupied  rooms  beneath  that  of  the  Manager,  and  with  the  same  exposure,  were 
attacked,  but  recovered ;  four  others,  lodged  in  similar  rooms  with  a  southern 
exposure,  entirely  escaped.  The  Apothecary  and  coach-driver,  who  occupied 
rooms  in  the  men's  wing  with  windows  opening  to  the  north,  were  both  attacked, 
but  both  recovered.  Among  the  pauper  inmates  of  the  wings,  those  generally 
were  seized- who  slept  in  the  northern  wards;  and  it  was  observable  that  the  male 
side  suffered  generally  much  more  severely  than  the  female,  —  a  difference  not 
attributable  to  anything  in  the  building  or  its  inhabitants,  but  at  once  explained 
by  the  fact,  that  whilst  no  barrier  existed  between  the  male  side  and  the  putrid 
marsh,  the  female  wing  was  protected  from  the  pestilential  current  by  three  in- 
tervening rows  of  trees.1  On  the  female  side,  however,  a  building  ran  in  a  north 
and  south  direction,  of  which  the  lower  story  had  a  door  in  the  north,  opening 

1  These  probably  acted  not  merely  mechanically,  by  obstructing  the  current,  but  also 
chemically  by  decomposing  or  oxidating  the  noxious  emanations.  For  it  has  been  frequently 
remarked,  that  a  screen  or  belt  of  umbrageous  trees  effectually  secures  the  dwellers  on  the 
borders,  and  even  on  the  leeward  side,  of  the  most  pestiferous  marshes,  from  the  effects 
of  their  malaria.  How  far  they  have  the  same  influence  on  animal  effluvia,  we  are  not 
Tf»t  in  a  position  to  state 


EFFECTS   OF    RESPIRATION    OF   A   VITIATED   ATMOSPHERE.          323 

quite  near  the  putrid  marsh,  whilst  the  upper  stories  had  only  a  blank  wall  at 
this  end ;  this  lower  story  was  tenanted  by  seventeen  lunatics,  all  of  whom  were 
attacked  with  Cholera,  and  all  died,  whilst  not  a  single  attack  of  Cholera  took 
place  among  the  inmates  of  its  upper  stories.  And  in  addition,  it  was  noticed 
that  the  removal  of  the  Cholera  patients  to  the  ward  above  the  black  people's 
hospital,  where  the  miasmatic  influence  was  entirely  unobstructed,  was  attended 
with  a  marked  aggravation  of  their  malady. 

336.  Now  although  the  Cholera-epidemics  have  been  here  referred-to,  as  afford- 
ing the  most  remarkable  examples  of  the  influence  of  a  contaminated  atmosphere 
in  predisposing  the  individuals  habitually  living  in  it  to  the  invasion  of  Zymotic 
disease,  yet  the  evidence  is  not  less  strong  in  regard  to  the  uniform  prevalence 
of  ordinary  Fevers,  &c.,  in  the  same  localities ;  the  places  in  which  Cholera  was 
the  most  severe,  having  been  almost  invariably  known  as  'fever-nests'  in  other 
periods,  and  being  distinguished  by  a  very  high  rate  of  mortality.  Thus  the 
average  age  of  all  persons  who  die  in  Witham,  is  only  18  years ;  whilst  the  average 
age  at  death  in  the  town  of  Hull  (itself  distinguished  by  an  unusual  brevity  of 
life)  is  23  years. — In  the  '  Potteries'  at  Kensington,  a  locality  in  which  filth  and 
overcrowding  prevail  to  an  almost  unequalled  degree,  the  mortality  for  three 
years  previously  to  the  invasion  of  cholera  had  been  such,  that  the  average  age 
at  death  was  only  11  yrs.  7  mo. ;  and  in  the  first  ten  months  of  1849,  out  of  a 
population  of  about  1000,  there  were  50  deaths,  of  which  21  were  from  cholera 
and  diarrhoea,  and  29  from  typhus  fever  and  other  diseases.  It  is  illustrative  of 
the  common  points  between  cholera  and  other  zymotic  diseases,  that  the  former 
appeared  there  not  only  in  the  same  streets  and  in  the  same  houses,  but  even  in 
the  same  rooms,  which  had  been  again  and  again  visited  by  typhus ;  and  there 
were  several  tenants  of  such  rooms,  who  only  recovered  from  fever  in  the  spring, 
to  fall  victims  to  cholera  in  the  summer.  Subsequently  to  this  epidemic,  the 
average  age  at  death  has  been  further  reduced,  by  an  increase  of  infantile  mor- 
tality, to  as  low  as  10  years.  —  By  way  of  contrast,  it  may  be  stated  that  in  one 
of  the  "  Model  Lodging-Houses,"  containing  about  550  inmates,  among  whom 
was  an  unusually  large  proportion  of  children,  the  rate  of  mortality  during  the 
three  years  ending  May,  1851  (including  the  whole  period  of  the  cholera-epide- 
mic), was  scarcely  more  than  20  in  1000 ;  the  proportion  of  deaths  under  ten 
years  of  age  was  only  half  that  of  the  metropolis  in  general ;  there  was  not  a 
single  attack  of  cholera,  and  there  were  only  a  few  cases  of  choleraic  diarrhoea, 
although  the  disease  was  raging  in  the  immediate  vicinity;  and  from  the  time 
that  the  sewerage  had  been  put  into  complete  order,  typhus  fever  had  entirely 
disappeared,  a  few  cases  having  occurred  soon  after  the  opening  of  the  buildings, 
which  were  distinctly  traceable  to  a  defect  in  the  drainage.1 — The  following  case 
may  be  added,  in  proof  of  the  potency  of  an  atmosphere  charged  with  putrescent 
emanations,  in  rendering  the  system  liable  to  the  attacks  of  Zymotic  diseases  of 
various  kinds.  A  manufactory  of  artificial  manure  formerly  existed  immediately 
opposite  Christchurch  workhouse,  Spitalfields,  which  building  was  occupied  by 
about  400  children,  with  a  few  adult  paupers.  Whenever  the  works  were  actively 
carried-on,  particularly  when  the  wind  blew  in  the  direction  of  the  house,  there 
were  produced  numerous  cases  of  fever,  of  an  intractable  and  typhoid  form ;  a 
typhoid  tendency  was  also  observable  in  measles,  small-pox,  and  other  infantile 
diseases,  and  for  some  time  there  prevailed  a  most  unmanageable  and  fatal  form 
of  aphthae  of  the  mouth,  ending  in  gangrene.  From  this  last  cause  alone,  12 
deaths  took  place  among  the  infants  in  three  months.  In  the  month  of  Decem- 
ber, 1848,  when  cholera  had  already  occurred  in  the  neighbourhood,  60  of  the 
children  in  the  workhouse  were  suddenly  seized  with  violent  diarrhoea  in  the 
early  morning.  The  proprietor  was  compelled  to  close  his  establishment,  and 

1  "Op.  cit.,"  App.  B,  pp.  48  and  77:  and  Mr.  Grainger's  subsequent  "Report  on  the 
present  state  of  certain  parts  of  the  Metropolis,  and  on  the  Model  Lodging-Houses  of 
London,"  pp.  29,  36. 


324  OF     RESPIRATION. 

the  children  returned  to  their  ordinary  health.  Five  months  afterwards,  the 
works  were  recommenced;  in  a  day  or  two  subsequently,  the  wind  blowing  from 
the  manufactory,  a  most  powerful  stench  pervaded  the  building.  In  the  night 
following,  45  of  the  boys,  whose  dormitories  directly  faced  the  manufactory,  were 
again  suddenly  seized  with  severe  diarrhoea ;  whilst  the  girls,  whose  dormitories 
were  in  a  more  distant  part,  and  faced  in  another  direction,  escaped.  The  ma- 
nufactory having  been  again  suppressed,  there  was  no  subsequent  return  of 
diarrhoea.1 

337.  It  may  not  be  amiss  to  add  a  few  examples  drawn  from  the  experience 
which  our  Indian  possessions  have  afforded,  of  the  influence  of  an  insufficient 
supply  of  pure  air  upon  the  ordinary  mortality  in  our  army  and  among  the  people 
under  our  control. — There  are  various  military  stations,  which  have  lain  under  a 
most  ill-deserved  repute  for  unhealthiness,  in  consequence  of  the  very  imperfect 
barrack-accoramodation  afforded  to  the  troops  quartered  in  them.     Thus  at  Secun- 
derabad,  in  the  Madras  command,  the  average  annual  mortality  for  the  fifteen 
years  previous  to  1846-7,  was  75  per  1000 ;  this  being  nearly  double  the  average 
of  the  whole  presidency,  and  more  than  double  that  of  the  remainder  of  the  sta- 
tions.    Now  the  complaints  made  year  after  year,  by  the  medical  officers  of  the 
troops  which  have  been  successively  quartered  at  this  station,  leave  no  room  for 
doubt  as  to  the  chief  cause  of  this  excess ;  for  the  regiments  of  the  Line  quartered 
at  Secuuderabad  have  been  always  crowded  in  barracks  quite  insufficient  for  their 
accommodation,  one-third  of  the  men  having  been  obliged  to  sleep  in  the  veran- 
dahs, and  the  remainder  getting  by  no  means  a  due  allowance  of  fresh  air; 
whilst,  on  the  other  hand,  the  Officers  of  these  very  regiments,  who  are  better 
accommodated,  and  the  detachment  of  Artillery  quartered  in  more  roomy  barracks 
at  no  great  distance,  have  never  participated  in  this  unusual  mortality,  thereby 
clearly  showing  the  absence  of  any  special  causes  of  disease  at  this  station,  which 
might  not  be  easily  removed.2 — The  Barrackpore  station,  in  the  Bengal  command, 
is  even  worse  than  the  foregoing;  for  every  regiment  quartered  there,  seems  to 
suffer  an  almost  complete  decimation  annually.     Yet  there  is  ample  evidence, 
that  here  also  the  chief  fault  lies  in  the  barrack-accommodation.     But  one  of  the 
most  terrible  instances  of  the  continuance  of  a  high  rate  of  mortality,  which  is 
almost  entirely  attributable  to  an  insufficient  supply  of  air,  is  that  which  is  fur- 
nished by  the  Gaols  under  British  control  in  India.     In  these  are  usually  con- 
fined no  fewer  than  40,000  prisoners,  chiefly  natives ;  and  the  average  annual 
mortality  of  the  whole  was  recently  10  per  cent.,  rising  in  some  cases  to  26  per 
cent.,  or  more  than  one  in  four.     This  is  easily  accounted  for,  when  it  is  known 
that  in  no  case  is  there  an  allowance  of  more  than  300  cubic  feet  of  air-space  for 
each  individual,  whilst  in  some  instances  70  cubic  feet  is  the  miserable  average.3 

338.  One  more  set  of  cases  will  be  cited,  as  showing  the  marked  effect  of  the 
habitual  respiration  of  the  contaminated  atmosphere,  not  merely  in  engendering  a 
liability  to  zymotic  disease,  but  in  directly  producing  a  special  form  of  infantile 
spasmodic  disease,  of  the  most  fearful  nature. — The  dwellings  of  the  great  bulk 
of  the  population  of  Iceland  seem  as  if  constructed  for  the  express  purpose  of 

1  "Report  of  the  Board  of  Health  on  Cholera,  1848-9,"  p.  42. 

a  It  is  a  remarkable  confirmation  of  the  view  formerly  stated  (g  65),  as  to  the  tendency 
of  the  habitual  use  of  Alcoholic  liquors  to  induce  a  '  fermentible'  condition  of  the  blood,  by 
obstructing  the  elimination  of  the  effete  matters  by  the  respiratory  process  (§  316  vn), 
that  when  the  84th  Regt.,  which  is  distinguished  for  its  sobriety,  was  quartered  at  Secun- 
derabad  in  1847-8,  it  lost  only  39  men  out  of  1139,  or  34-2  per  1000,  the  average  mor- 
tality of  the  other  stations  in  the  Presidency  being  about  the  same  as  usual.  On  the  other 
hand,  the  63rd  Regt.,  which  was  far  from  deserving  a  reputation  for  temperance,  had  lost 
73  men  during  the  first  nine  months  of  the  preceding  year,  or  at  the  rate  of  78-8  per  1000 
during  the  entire  year. — All  the  facts  here  stated  in  regard  to  Secunderabad,  have  been 
obtained  by  the  Author  direct  from  the  Army  Medical  Returns. 

8  Dr.  Mackinnon's  "Treatise  on  the  Public  Health,  &c.,  of  Bengal,"  Cawnpore,  1848, 
chap.  1. 


EFFECTS    OF    RESPIRATION    OF    A    VITIATED    ATMOSPHERE.          325 

poisoning  the  air  which  they  contain.  They  are  small  and  low,  without  anj 
direct  provision  for  ventilation,  the  door  serving  alike  as  window  and  chimney ; 
the  walls  and  roof  let  in  the  rain,  which  the  floor,  chiefly  composed  of  hardened 
sheep-dung,  sucks  up ;  the  same  room  generally  serves  for  all  the  uses  of  the 
whole  family,  and  not  only  for  the  human  part  of  it,  but  frequently  also  for  the 
sheep,  which  are  thus  housed  during  the  severer  part  of  the  winter.  The  fuel 
employed  in  the  country  districts  chiefly  consists  of  cow-dung  and  sheep-dung, 
caked  and  dried  ;  and  near  the  sea-coast,  of  the  bones  and  refuse  of  fish  and  sea- 
fowl ;  producing  a  stench,  which,  to  those  unaccustomed  to  it,  is  completely 
insupportable.  In  addition  to  this,  it  may  be  mentioned  that  the  people  are 
noted  for  their  extreme  want  of  personal  cleanliness;  the  same  garments  (chiefly 
of  black  flannel)  being  worn  for  months  without  being  even  taken-off  at  night. 
Such  an  assemblage  of  unfavourable  conditions,  combined  with  the  cold  damp 
nature  of  the  climate,  might  have  been  expected  to  induce  tubercular  diseases 
of  various  kinds;  but  from  these  the  Icelanders  appear  to  enjoy  a  special  exemp- 
tion (§  57  in).  Syphilis,  also,  is  wanting,  or  nearly  so;  and  yet,  notwithstanding 
that  the  number  of  births  is  fully  equal  to  the  usual  average,  the  population  is 
stationary,  and  in  some  parts  actually  diminishing.  This  is  partly  due  to  the 
extent  and  fatality  of  the  epidemic  diseases,  of  which  some  one  or  other  spreads 
through  the  island  nearly  every  year;  but  it  is  chiefly  owing  to  the  extraordinary 
mortality  of  infants  from  Trismus  nascentium,  which  carries-off  a  large  propor- 
tion of  them  between  the  fifth  and  the  twelfth  days  after  their  birth.  It  is  in  the 
little  island  of  Westmannoe  and  the  opposite  parts  of  the  coast  of  Iceland,  where 
the  bird-fuel  is  used  all  the  year  round,  instead  of  (as  elsewhere)  during  a  few 
mouths  only,  that  this  disease  is  most  fatal ;  the  average  mortality  for  the  last 
twenty  years,  during  the  first  twelve  days  of  infantile  life,  being  no  less  than  64 
per  cent.,  or  nearly  two  out  of  three} — Now  it  is  not  a  little  remarkable  that  the 
very  same  disease  should  have  prevailed,  under  conditions  almost  identically  the 
same,  in  the  island  of  St.  Kilda,  one  of  the  Western  Hebrides;  the  state  of 
which  was  made  known  by  Mr.  Maclean,  who  visited  it  in  1838.  The  population 
of  this  island,  too,  was  diminishing  rather  than  increasing,  in  consequence  of  the 
enormous  infantile  mortality ;  four  out  of  every  jive  dying,  from  Trismus  nas- 
ceritium,  between  the  eighth  and  twelfth  days  of  their  existence.  The  great,  if 
not  the  only,  cause  of  this  mortality,  was  the  contamination  of  the  atmosphere  by 
the  filth  amidst  which  the  people  lived.  Their  huts,  like  those  of  the  Icelanders, 
were  small,  low-roofed,  and  without  windows ;  and  were  used  during  the  winter 
as  stores  for  the  collection  of  manure,  which  was  carefully  laid-out  upon  the  floor, 
and  trodden  underfoot  to  the  depth  of  several  feet.  On  the  other  hand,  the 
clergyman,  who  lived  exactly  as  did  those  around  him,  except  as  to  the  condition 
of  his  house,  had  brought  up  a  family  of  four  children  in  perfect  health ;  whereas, 
according  to  the  average  mortality  around  him,  at  least  three  out  of  the  four  would 
have  been  dead  within  the  first  fortnight. — Of  the  degree  in  which  this  fearful 
disease  is  dependent  upon  impurity  of  the  atmosphere,  and  is  preventible  by  ade- 
quate ventilation,  abundant  proof  is  afforded  by  the  experience  of  Hospitals  and 
Work-houses  in  our  own  country.  Thus  in  the  Dublin  Lying-in  Hospital,  up  to 
the  year  1782-,  the  mortality  within  the  first  fortnight,  almost  entirely  from  Tris- 
mus nascentium,  was  1  in  every  6  children  born.  The  adoption,  under  the 
direction  of  Dr.  Joseph  Clarke,  of  an  improved  system  of  ventilation,  reduced 
the  proportion  of  deaths  from  this  cause  to  1  in  19 £.  And  further  improvements 
in  ventilation,  with  increased  attention  to  cleanliness,  during  the  seven  years  in 
which  Dr.  Collins  was  Master  of  this  Institution,  reduced  the  number  of  deaths 
from  this  disease  to  ^10  more  than  three  or  four  yearly.2 — A  similar  amelioration 

1  See  "  Island  undersogt  fra  laegevidenskabeligt  Synspunct."    Af  P.  A.  Schleisner,  M.D. 
—Copenhagen,  1849. 

9  See  Dr.  Collins's  "Practical  Treatise  on  Midwifery,"  p.  513. 


326  OF    RESPIRATION. 

took  place  about  a  century  ago,  in  the  condition  of  the  London  Workhouses,  in 
which  23  out  of  24  infants  had  previously  died  within  the  first  year,  and  a  large 
proportion  of  these  within  the  first  month ;  for  owing  to  a  parliamentary  inquiry 
which  was  called-forth  by  this  fearful  state  of  things,  the  proportion  of  deaths 
was  speedily  reduced  (chiefly  by  improvement  in  ventilation)  from  2600  to  450 
annually. 

339.  Thus  it  appears  that  in  all  climates,  and  under  all  conditions  of  life,  the 
purity  of  the  atmosphere  habitually  respired  is  essential  to  the  maintenance  of 
that  power  of  resisting  disease,  which,  even  more  than  the  ordinary  state  of 
health,  is  a  measure  of  the  real  vigour  of  the  system.  For,  owing  to  the  extra- 
ordinary capability  which  the  human  body  possesses  of  accommodating  itself  to 
circumstances,  it  not  unfrequently  happens  that  individuals  continue  for  years  to 
breathe  a  most  unwholesome  atmosphere,  without  apparently  suffering  from  it ; 
and  thus,  when  they  at  last  succumb  to  some  Epidemic  disease,  their  death  is 
attributed  solely  to  the  latter ;  the  previous  preparation  of  their  bodies  for  the 
reception  and  development  of  the  zymotic  poison,  being  altogether  overlooked. 
It  is  impossible,  however,  for  any  one  who  carefully  examines  the  evidence,  to 
hesitate  for  a  moment  in  the  conclusion,  that  the  fatality  of  Epidemics  is  almost 
invariably  in  precise  proportion  to  the  degree  in  which  an  impure  atmosphere  has 
been  habitually  respired;  that  an  atmosphere  loaded  with  putrescent  miasmata 
may  afford  a  nidus  wherein  zymotic  poison  undergoes  a  marked  increase  in  quan- 
tity and  intensity,  the  putrescent  exhalations  from  the  lungs  and  skin  of  the 
living  subject  being  at  least  as  effectual  in  furnishing  such  a  '  nidus/  as  are  the 
emanations  from  faecal  discharges  or  from  other  decomposing  matters;  that  the 
habitual  respiration  of  such  an  atmosphere  tends  to  induce  a  condition  of  the 
blood,  which  renders  it  peculiarly  susceptible  of  perversion  by  the  introduction 
of  zymotic  poisons,  and  which  favours  their  multiplication  within  the  system ; ' 
and  lastly,  that  by  due  attention  to  the  various  means  of  promoting  atmospheric 
purity,  and  especially  by  efficient  ventilation  and  sewerage,  the  rate  of  mortality 
may  be  enormously  decreased,  the  amount  and  severity  of  sickness  lowered  in  at 
least  an  equal  proportion,  and  the  fatality  of  epidemics  almost  completely  anni- 
hilated. And  it  cannot  be  too  strongly  borne  in  mind,  that  the  efficacy  of  such 
preventive  measures  has  been  most  fully  substantiated,  in  regard  to  many  of  the 
very  diseases  in  which  the  curative  power  of  Medical  treatment  has  seemed  most 
doubtful;  as  for  example,  in  Cholera  and  Malignant  Fevers. — The  practical  im- 
portance of  this  subject  may  be  estimated  from  the  startling  fact,  which  enquiries 
prosecuted  under  the  direction  of  the  Board  of  Health  have  recently  brought  to 
light;2  —  viz.,  that  the  difference  in  the  annual  rates  of  mortality,  between  the 
most  healthy  and  the  most  unhealthy  localities  in  England,  amounting  to  no 
less  than  34  in  1000,  is  almost  entirely  due  to  Zymotic  diseases,  which  might  be 
nearly  (if  not  completely)  exterminated  by  well-devised  sanitary  arrangements. 
The  lowest  actual  mortality  is  11  per  1000,  while  the  highest  is  45  per  1000 ;  and 
between  these  extremes,  there  is  every  intermediate  degree  of  range.  But  what 
may  be  termed  the  inevitable  mortality,  —  arising  from  diseases  which  would  not 
be  directly  affected  by-  Sanitary  improvements  —  is  a  nearly  constant  quantity 
throughout;  namely,  the  11  per  1000  of  those  districts  which  are  free  from 
Zymotic  disease.  The  average  mortality  of  all  England,  in  ordinary  years,  is 

1  A  careful  consideration  of  the  very  satisfactory  evidence  which  has  been  of  late  years 
collected  on  this  point,  must  (in  the  Author's  opinion)  satisfy  any  competent  and  unpre- 
judiced inquirer,  that  Endemic  Fevers,  originating  in  local  causes  (marsh  miasmata  and  the 
like),  and  at  first  affecting  only  those  who  are  exposed  to  such  causes,  may  find,  by  the 
crowding-together  of  infected  subjects,  a  nidus  for  development  within  the  Human  system  ; 
so  that  these  diseases  then  become  communicable  by  human  intercourse,  although  not  so 
originally. — For  a  discussion  of  this  subject,  see  the  Articles  on  '  Yellow  Fever '  and  the 
•  Fever  of  Boa  Vista,'  in  the  "Brit,  and  For.  Med.-Chir.  Rev.,"  vols.  i.  ii.  and  iv. 

51  See  "  Summary  of  Experience  on  Disease,  and  Comparative  Rates  of  Mortality,"  by 
William  Lee,  Superintending  Inspector,  1851. 


FORMATIVE    POWER    OF    INDIVIDUAL    PARTS.         327 

about  22  per  1000,  or  just  double  that  to  which  it  might  be  reduced;  so  that, 
taking  the  population  of  England  and  Wales  (as  by  the  last  Census)  at  nearly 
18  millions,  the  average  annual  mortality  must  be  396,000,  of  which  only 
198,000  is  inevitable,  an  equal  amount  being  prevcntiUe. 


CHAPTER  VIII. 

OP    NUTRITION. 
1. —  General  Considerations.' — Formative  Power  of  Individual  Parts. 

340.  THE  function  of  Nutrition,  considered  in  the  widest  acceptation  of  the 
term,  includes  that  whole  series  of  operations,  by  which  t^e  alimentary  mate- 
rials,— prepared  by  the  Digestive  process,  introduced  into  the  system  by  Absorp- 
tion, and  carried  into  its  penetralia  by  the  Circulation,  —  are  converted  into 
Organized  tissue  :  but  in  a  more  limited  sense  it  may  be  understood  as  referring 
to  the  last  of  these  operations  only,  that  of  Histogenesis  or  tissue-formation,  to 
which  all  the  other  organic  functions,  in  so  far  as  they  are  concerned  in  main- 
taining the  life  of  the  individual,  are  subservient,  by  preparing  and  keeping  in 
the  requisite  state  of  purity  the  materials  at  the  expense  of  which  it  takes  place. 
It  is  shown  elsewhere  (PRINC.  OF  GEN.  PHYS.,  Am.  Ed.),  that  every  integral  part 
of  the  living  body  possesses  a  certain  capacity  for  growth  and  development,  in 
virtue  of  which  it  passes  through  a  series  of  successive  phases,  under  the  influence 
of  the  steady  Heat,  which  in  the  warm-blooded  is  constantly  acting  upon  it;  this 
capacity  being  an  endowment  which  it  derives  by  direct  descent  from  the  original 
germ  (CHAP,  xvi.),  but  undergoing  a  gradual  diminution  with  the  advance  of 
life  (CHAP.  XViu.),  until  the  power  of  maintenance  is  no  longer  adequate  to 
antagonize  the  forces  that  tend  to  the  disintegration  of  the  system.  It  has  been 
also  shown  (CHAP,  v.),  that  notwithstanding  the  diversities  in  the  structure  and 
composition  of  the  several  tissues,  the  Blood  supplies  the  materials  which  each 
requires;  every  tissue  possessing  (so  to  speak)  an  elective  affinity  for  some  par- 
ticular constituents  of  that  fluid,  in  virtue  of  which  it  abstracts  them  from  it, 
and  appropriates  them  to  its  own  uses.  —  But  it  has  been  shown,  on  the  other 
band,  that  the  'formative  capacity'  does  not  exist  in  the  tissues  alone,  but  is 
shared  by  the  Blood,  which  must  itself  be  regarded  as  deriving  it  from  the  origi- 
nal germ ;  for  there  are  certain  simple  kinds  of  tissue,  which  appear  to  take  their 
origin  directly  in  its  plastic  components  (§  198).  Of  others,  which  cannot  be 
said  thus  to  originate  in  the  blood,  the  development  seems  to  be  entirely  deter- 
mined by  the  quantity  of  their  special  pabula  which  it  may  contain.  Thus,  an 
increase  of  Adipose  tissue  takes  place,  when  the  blood  habitually  includes  an 
unusual  amount  of  fat ;  an  augmentation  in  the  proportion  of  the  Red  Corpus- 
cles of  the  blood  may  be  distinctly  observed  (especially  if  it  has  been  previously 
diminished  unduly),  when  an  additional  supply  of  iron  is  afforded  (§  190) ;  and 
when  one  of  the  Kidneys  has  been  removed,  or  is  prevented  by  disease  from  per- 
forming its  normal  function,  the  other,  if  it  remain  healthy,  undergoes  an  extra- 
ordinary increase  in  size,  so  as  to  perform  the  duty  of  both  organs,  the  augmented 
development  of  its  secreting  structure  being  here  also  fairly  attributable  to  the 
accumulation  of  its  appropriate  materials  in  the  blood.1  Even  of  those  tissues 

1  This  principle  is  one  most  fertile  in  Pathological  applications:  for  there  can  be  little 
doubt  that  the  development  of  many  morbid  growths  is  due,  not  so  much  to  a  perverted 
local  action,  as  to  the  presence  of  certain  morbid  matters  in  the  blood,  which  determines 
the  formation  of  tissues  that  use  them  as  their  appropriate  pabulum.  Such  is  pretty 
obviously  the  case  with  those  disorders,  which  (like  the  Exanthemata)  are  universally 
admitted  to  be  of  '  constitutional '  character,  and  which  are  distinctly  traceable  to  a  poison 
introduced  through  the  blood,  whose  first  influence  is  exerted  in  modifying  the  physical 


328  OF    NUTRITION. 

which  must  be  considered  as  most  independent  and  self-sustaining,  the  develop- 
ment is  not  only  checked  by  the  want  of  a  due  supply  of  their  appropriate  mate- 
rials, but  it  is  modified  in  a  very  remarkable  degree  by  the  presence  of  abnormal1 
substances  in  the  blood,  which  single-out  particular  parts,  and  effect  determinate 
alterations  in  their  nutrition,  in  such  a  constant  manner  as  to  show  the  existence 
of  a  peculiar  <  elective  affinity '  between  them  (§  217).  —  In  so  far,  then,  as  the 
process  of  Nutrition  is  dependent  upon  the  duo  supply  and  normal  state  of  the 
Blood,  its  conditions  have  been  already  sufficiently  discussed;  and  we  have  now 
only  to  consider  it  in  its  relations  to  the  Tissues. 

341.  The  demand  for  Nutrition  primarily  arises  from  the  tendency  of  the 
organism  to  simple  Increase  or  Growth.  Of  this  we  have  the  most  characteristic 
illustration  in  the  multiplication  of  the  first  embryonic  cell,  by  the  simple  process 
of  '  duplicative  subdivision;'  whereby  a  multitude  of  cells  is  produced,  every  one 
of  which  is  similar  in  all  essential  particulars  to  the  original.  But  after  the  dif- 
ferent parts  of  this  homogeneous  embryonic  mass  have  taken  upon  themselves 
their  respective  modes  of  development,  so  as  to  generate  a  diversity  of  tissues 
and  organs,  each  one  of  these  continues  to  increase  after  its  own  plan ;  and  thus 
the  child  becomes  the  adult,  with  comparatively  little  change  but  that  of  growth 
(CHAP.  XVI.,  Sect.  4).  An  excess  of  growth,  taking  place  conformably  to  the 
normal  place  of  the  tissue  or  organ,  constitutes  Hypertrophy  ;  whilst  a  diminu- 
tion, without  degeneration  or  alteration  of  structure,  is  that  which  is  properly 
distinguished  as  Atrophy. — But  Growth  is  not  confined  to  the  period  of  increase 
of  the  body  generally;  for  it  may  manifest  itself  in  particular  organs  or  tissues, 
as  a  normal  operation,  at  any  subsequent  part  of  life;  as  when  an  extraordinary 
demand  for  the  functional  activity  of  a  particular  set  of  Muscles  is  supplied  by 
an  increase  in  the  amount  of  their  contractile  tissue. — And  further,  even  where 
there  is  no  such  manifestation  of  increase,  there  is  really  a  continual  growth  in 
all  the  tissues  actively  concerned  in  the  vital  operations,  and  this  even  to  the  very 
end  of  life ;  although  it  may  be  so  far  counterbalanced,  or  even  surpassed,  by 
changes  of  an  opposite  kind  (§  22),  that  instead  of  augmentation  in  bulk,  there 
is  absolute  diminution. 

842.  The  evolution  of  the  complete  organism  from  its  germ,  however,  does 
not  consist  in  mere  growth ;  for  by  such  a  process  nothing  would  be  produced 
but  an  enormous  aggregation  of  simple  cells,  possessing  little  or  no  mutual  depen- 
dence, like  those  which  constitute  the  shapeless  masses  of  the  lowest,  Algae  (See 
PRINC.  OF  GEN.  PHYS.,  Am.  Ed).  In  addition  to  increase  there  must  be  Develop- 
ment, that  is,  a  passage  to  a  higher  condition,  both  of  form  and  structure ;  so  that 
the  part  in  which  this  change  takes  place  becomes  fitted  for  some  special  function, 
and  is  advanced  towards  the  state  in  which  it  exists  in  the  highest  or  most  com- 
pleted form  of  its  specific  type.  Thus  the  development  of  tissue  consists  in  the 
change  from  a  simple  mass  of  cells  or  fibres  into  any  other  form ;  as  in  the  pro- 
duction of  Dentine  from  the  cellular  substance  of  the  tooth  pulp,  or  in  the 
formation  of  Bone  in  the  sub-periosteal  membrane.  So,  again,  the  developmental 
change  is  seen  in  the  passage  of  an  entire  organ  from  a  lower  to  a  higher  condi- 
tion, by  the  evolution  of  new  parts,  or  by  a  change  in  the  relations  of  those 
already  existing,  even  though  the  change  in  its  texture  should  consist  of  little 
else  than  of  simple  increase  :  thus  in  the  development  of  the  Heart,  we  have  \ 
the  original  single  cavity  subdivided,  first  into  two,  and  at  last  into  four  chambers  : 

and  vital  properties  of  that  fluid :  and  the  evidence  has  been  of  late  accumulating,  that  it  ; 
is  true  also  of  the  various  forms  of  Cancer ;  the  local  development  of  an  abnormal  struc- 
ture being  in  this  case,  also,  nothing  else  than  the  manifestation  of  the  existence  of  that 
peculiar  matter  in  the  blood,  "which  is  the  appropriate  nutriment  of  its  component  tissues, 
(\  231);  or,  as  Mr.  Simon  appropriately  designates  it,  "a  new  excretory  organ,  which 
tends  essentially  to  acts  of  eliminative  secretion,  just  as  distinctly  as  the  healthy  liver 
or  the  healthy  kidney." — See  Mr.  Simon's  "Lectures  on  General  Pathology,"  p.  116,  Am. 
Ed.;  and  Mr.  Paget's  "Lectures  on  Surgical  Pathology,"  pp.  329  and  362,  et  seq., 
Am.  EC;.. 


FORMATIVE     POWER     OF    INDIVIDUAL    PARTS.          329 

and  in  the  development  of  the  Brain,  we  find  the  sensory  ganglia  to  be  the  parts 
first  formed,  the  anterior  lobes  of  the  cerebrum  to  be  evolved  (as  it  were)  from 
these,  the  middle  lobes  sprouting-forth  from  the  back  of  the  anterior,  and  the 
posterior  from  the  back  of  the  middle j  yet  with  all  this,  there  is  no  production 
of  any  new  kind  of  tissue,  the  new  parts  being  generated  at  the  expense  of 
histological  components  identical  with  those  of  the  pre-existing. — Now  it  is  in 
the  early  period  of  embryonic  life,  that  the  developmental  process  is  most 
remarkably  displayed ;  for  it  is  then  that  we  see  that  transformation  of  the 
primordial  cells  into  tissues  of  various  kinds,  which  originates  a  special  nisus  in 
each  part,  whereby  the  production  of  the  same  tissue,  in  continuity  with  that 
first-formed,  comes  to  be  a  simple  act  of  growth ;  and  it  is  then  also  that  we 
observe  that  marking-out  of  all  the  principal  organs  by  the  development  of  tissue 
in  particular  directions,  which  makes  all  subsequent  evolution  but  a  completion 
or  n'lling-up  of  the  plan  thus  sketched-out.  Thus,  during  the  first  days  of  incu- 
bation in  the  Chick,  the  foundation  is  laid  of  the  vertebral  column,  the  nervous 
centres,  the  organs  of  sense,  the  heart  and  circulating  system,  the  alimentary 
canal,  the  respiratory  apparatus,  the  liver,  the  kidneys,  and  many  other  parts; 
and  at  the  termination  of  that  period,  the  chick  emerges  in  such  a  state  of  com- 
pleteness of  development,  that  little  else  than  increase  is  wanting,  save  in  the 
plumage  and  sexual  organs,  to  raise  it  to  its  perfect  type.  The  same  may  be  said 
of  the  Human  organism  ;  save  that  the  period  of  its  development  is  relatively 
longer,  in  accordance  with  the  higher  grade  which  it  is  ultimately  to  attain ;  its 
earliest  stages  being  passed-through,  however,  with  extraordinary  rapidity.  The 
completer  evolution  of  the  generative  organs,  of  the  osseous  skeleton,  and  of  the 
teeth,  constitute  the  principal  developmental  changes  which  the  Human  onranisni 
undergoes  in  its  progress  from  the  infantile  to  the  adult  condition  ;  almost  every 
other  alteration  consisting  in  simple  increase  of  its  several  component  tissues  and 
organs,  without  any  essential  change  in  their  form  or  structure  And  when  the 
adult  type  has  been  once  completely  attained,  every  subsequent  change  is  one 
rather  of  degeneration  than  of  development,  of  retrogression  rather  than  of 
advance. 

343.  The  difference  between  these  two  processes  of  Growth  and  Development 
is  most  characteristically  shown  in  those  cases,  in  which  there   is  a  partial  or 
complete  arrest  of  one  of  them,  without  any  corresponding  impairment  of  the 
other.     Thus  a  dwarf,  however  small  in  stature,  may  present  a  perfect  develop- 
ment of  every  part  that  is  characteristic  of  the  complete  human  organism  ;  the 
deficiency  being  solely  in  the  capacity  for  growth.     On  the  other  hand,  the  usual 
size  at  birth  may  be  attained,  and  every  organ  may  present  its  ordinary  dimen- 
sions, and  yet  some  important  part  may  be  found  in  a  condition  of  arrested 
development :  thus  the  Heart  may  consist  of  a  single  cavity,  or  the  inter-ventric- 
ular or  inter-auricular  septa  may  be  incomplete,  so  that  it  has  not  passed  beyond 
the  grade  of  development  which  it  had  attained  at  an  early  period  of  embryonic 
life,  although  its  growth  may  have  continued  ;  or  the  Brain  may  in  like  manner 
exhibit  a  deficiency  of  the  posterior  lobes,  or  of  the  corpus  callosum,  or  of  some 
part  whose  formation  normally  takes  place  in  the  latter  months  of  intra-uterine 
life,  although  the  parts  already  produced  may  have  continued  to  grow  at  their 
usual  rate. — Numerous  instances  of  the  same  kind  might  be  cited,  but  these 
must  suffice. 

344.  The  demand  for  Nutrition  arises,  however,  not  merely  from  the  exercise 
of  the  formative  powers  which  are  concerned  in  the  building-up  of  the  organism, 
but  also  from  the  degeneration  and  decay  which  are  continually  taking-place  in 
almost  every  part  of  it,  and  the   effects  of  which,  if  not  antagonized,  would 
speedily  show  themselves  in  its  complete  disintegration.     As  each  component  cell 
of  the  organism  has  to  a  certain  degree  an  independent  life  of  its  own,  so  has  it 
ako  a  limited  duration  ;  and  its  duration  usually  bears  an  inverse  ratio  to  its  func- 
tional activity  (See  PRINC.  OF  GEN.  PHYS.;  Am.  Ed).     This  is  particularly  strik- 


330  OF    NUTRITION. 

ing,  when  we  compare  the  ratio  of  change  in  the  organisms  of  cold-blooded 
animals  at  low  and  high  temperatures  ;  for  they  live  slowly,  need  little  nutriment, 
give-off  but  a  small  amount  of  excretory  products,  and  require  a  long  time  for 
the  performance  of  the  reparative  processes,  under  the  former  condition  ;  but 
live  fast,  require  a  comparatively  large  supply  of  nutriment,  give-off  a  far  greater 
amount  of  carbonic  acid  and  other  excretions,  resulting  from  the  '  waste'  of  tissue, 
and  exhibit  a  far  more  rapid  reparation  of  injuries,  in  the  latter  state.  The  con- 
stantly-high temperature  of  Man,  as  of  other  warm-blooded  animals,  prevents 
this  difference  from  being  displayed  in  him  in  a  similar  manner;  but  it  is  well 
seen  when  we  contrast  his  different  tissues  with  each  other,  and  study  their  re- 
spective histories.  For  whilst  there  are  some  (i.)  which  appear  to  pass  through 
all  their  stages  of  growth,  maturation,  and  decline,  within  a  limited  period,  there 
are  others  (n.)  whose  existence  seems  capable  of  almost  indefinite  prolongation, 
and  others  (ill.),  again,  which  are  liable  to  have  a  period  put  to  their  life  at  any 
time,  by  the  direction  of  their  vital  force  into  othor  channels. 

I.  Of  those  belonging  to  the  first  category,  which  are  actively  concerned  in  the 
purely-vital  operations  of  the  organism,  a  characteristic  example  is  presented  by 
the  Ovule;  which,  if  not  fertilized  within  a  limited  period  after  its  maturation, 
speedily  declines  and  decays;  and  the  same  law  of  limited  duration  doubtless 
extends  to  a  large  proportion  of  such  tissues  as  are  actively  concerned  in  the 
maintenance  of  the  organic  functions;  as  for  example,  the  Corpuscles   of  the 
blood  (§  166),  the  Epithelial  cells  of  many  glands  which  are  instrumental  in  the 
process  of  Secretion  (§  379),  the  cells  forming  the  parenchyma  of  the  Absorbent 
and  Vascular  Glands  (§§  131,  142  III.),  and  many  others. 

II.  The  contrary  extreme  to  this  may  be  found  in  those  tissues,  whose  func- 
tions are  rather  physical  than  vital ;  and  especially  in  such  as  undergo  consolida- 
tion by  the  deposit  of  solidifying  matter,  either  in  combination  with  the  animal 
membrane  or  fibre,  or  in  its  interstices.     Such  tissues  are  more  withdrawn  from 
the  general  current  of  vital  action ;  and  there  seems  to  be  no  definite  limit  to  the 
duration  of  some  of  them,  except  such  as  is  imposed  by  the  chemical  and  me- 
chanical degradation  to  which  they  may  be  subjected.     This  appears  to  be  the 
case  with  the  simple  Fibrous  tissues,  especially  the  yellow,  even  in  their  soft  or 
unconsolidated  state ;  but  it  is  far  more  obvious  in  the  dentine  an'd  enamel  of 
Teeth,  which  are  formed  by  the  combination  of  calcareous  salts  with  an  animal 
matrix,  and  which  retain  their  condition  apparently  unchanged  through  the  whole 
remainder  of  life,  under  circumstances  which  show  that  if  any  nutritive  action 
take  place  in  them,  its  amount  must  be  extremely  small.     In  the  dentinal  struc- 
tures of  the  young,  however,  there  is  obviously  a  determinate  limit  of  existence; 
as  is  shown  by  the  exuviation,  at  a  certain  definite  epoch,  of  the  first  set  of  teeth, 
which  exuviation  is  usually  preceded  by  the  death  and  partial  disintegration  of 
their  texture.     In  Hair,  Nails,  and  other  Epidermic  appendages,  again,  whose 
substance,  when  once  it  has  undergone  consolidation  by  the  deposit  of  horny 
matter,  may  remain  unchanged  for  centuries,  we  must  recognise  the  same  prin- 
ciple of  indefinite  duration,  in  connection  with  the  cessation  of  vital  activity ; 
the  chemical  constitution  of  these  textures,  moreover,  being  such  as  renders  them 
but  little  prone  to  be  acted-upon  by  ordinary  decomposing  agencies.     The  limit 
of  existence  seems  more  determinate,  however,  in  Bone ;  for  not  only  do  we  find 
that  in  the  first  development  of  this  substance,  a  considerable  part  of  the  tissue 
originally  generated  by  the  consolidation  of  its  osseous  or  cartilaginous  matrix 
speedily  disappears,  and  that  during  the  whole  period  of  growth  of  the  shaft  of  a 
round  bone,  there  is  a  continual  removal  of  its  inner  and  older  portions,  whereby 
the  medullary  cavity  is  progressively  enlarged;  but  there  is  strong  evidence  that, 
even  after  the  bone  has  attained  its  full  dimensions,  a  replacement  of  old  Haver- 
sian  systems  by  new  is  continually  in  progress  (§  348). 

III.  In  the  case  of  the  Muscular  and  Nervous  tissues,  however,  we  trace  the 
r.peration  of  causes  that  differ  from  any  of  those  already  specified.     These  tissues 


FORMATIVE    POWER    OF    INDIVIDUAL    PARTS.  381 

are  doubtless  subject,  like  all  others  that  are  distinguished  by  their  vital  activity, 
to  the  law  of  limited  duration ;  for  we  find  that,  when  not  called  into  use,  they 
undergo  a  gradual  disintegration  or  wasting,  which  is  not  adequately  repaired  by 
the  nutritive  processes.  But  their  existence  as  living  structures  appears  to  be 
terminable  at  any  time,  by  the  exercise  of  their  functional  powers;  for  the  de- 
velopment of  muscular  contractility  or  of  nervous  force  seems  to  involve,  as  its 
necessary  condition,  a  metamorphosis  (so  to  speak)  of  the  vital  power  which  was 
previously  exercising  itself  in  the  nutritive  operations;  and  the  materials  of 
these  tissues,  now  reduced  to  the  condition  of  dead  matter,  undergo  those  re- 
gressive changes  which  speedily  convert  them  into  excrementitious  products. 
But  the  very  manifestation  of  their  peculiar  vital  endowments,  determines  an 
afflux  of  blood  towards  the  parts  thus  called  into  special  activity ;  and  from  this 
it  comes  to  pass,  that  the  nutrition  of  these  textures  is  promoted,  instead  of  being 
impaired,  by  the  losses  to  which  they  are  thus  subjected ;  so  that  their  constant 
exercise  occasions  an  augmentation,  rather  than  a  diminution,  of  their  substance, 
— a  due  supply  of  the  requisite  materials  being  always  presupposed. 

345.  Thus  it  comes  to  pass,  that  during  the  whole  period  of  active  life,  a  de- 
mand for  Nutrition  is  created  by  every  exertion  of  the  vital  powers,  but  more 
especially  by  the  evolution  of  the  Nervous  and  Muscular  forces.  The  production 
and  application  of  these,  indeed,  may  be  considered  as  the  great  end  and  aim  of 
the  Human  organism,  so  far  at  least  as  the  individual  is  concerned  ;  the  whole 
apparatus  of  Organic  life  being  subservient  to  the  building-up  and  maintenance 
of  the  Nervo-muscular  apparatus,  and  of  those  parts  of  the  fabric  (e.g.  the  bones, 
cartilages,  fibrous  textures,  &c.)  which  it  uses  as  its  mechanical  instruments. 
Thus  the  activity  of  all  the  Organic  operations,  when  once  the  full  measure  of 
growth  has  been  attained,  is  mainly  determined  by  that  of  the  Animal  functions; 
and  as  the  'rate  of  life'  of  all  the  parts  which  minister  to  the  former,  will  be 
proportioned  to  the  energy  with  which  they  are  called-upon  to  perform  their 
functions,  their  duration  will  diminish  in  the  same  proportion,  and  hence  occasion 
will  arise  for  their  continual  renewal.1  But  since,  in  the  attainment  of  the  adult 
condition,  the  productive  capacity  has  undergone  a  gradual  diminution,  whilst 
the  exercise  of  the  animal  powers  has  become  vastly  increased,  the  formative 
processes  are  only  capable  of  maintaining  the  organism  in  its  state  of  complete- 
ness and  vigour,  by  making-good  the  losses  consequent  upon  the  continual  disin- 
tegration to  which  it  is  subjected  by  its  nervo-muscular  activity.  And  with  the 
advance  of  years,  the  further  diminution  of  the  productive  capacity  involves, — 
on  the  one  hand,  a  progressive  decrease  in  the  substance  of  the  tissues  and  organs 
most  important  to  life  (their  bulk,  however,  frequently  remaining  unchanged,  or 
even  increasing,  in  consequence  of  the  accumulation  of  fat), — and  on  the  other, 
a  gradual  weakening  of  its  powers  of  action.  (See  CHAP,  xvin.) 

1  Such  an  excellent  illustration  is  afforded  by  the  phenomena  of  Vegetation,  of  the  doc- 
trines here  propounded,  that  it  scarcely  appears  desirable  to  pass  it  by  in  this  place,  al- 
though it  has  been  elsewhere  more  fully  referred-to  ("  PRINC.  OF  COMP.  PHYS.,"  \\  265,  358, 
Am.  Ed). — The  leaves  of  Plants  serve,  like  the  absorbing  and  assimilating  cells  of  Animals, 
for  the  introduction  and  elaboration  of  the  nutritive  materials  which  are  to  be  applied  to 
the  extension  of  the  fabric ;  the  more  permanent  and  inactive  parts  of  which  are  thus 
generated  at  the  expense  of  materials  prepared  by  the  vital  operations  of  the  more  tran- 
sitory and  energetic  ($  20).  Now  there  is  an  obvious  limit  to  the  duration  of  the  leaf- 
cells  ;  but  this  limit  is  not  precisely  one  of  time,  being  rather  dependent  upon  the  comple- 
tion of  their  series  of  vital  actions.  Thus,  although  we  are  accustomed  to  look  upon  the 
'fall  of  the  leaves'  (which  is  nothing  else  than  an  exuviation  consequent  upon  death)  as  a 
phenomenon  of  regular  seasonal  recurrence,  and  to  regard  their  replacement,  by  a  new 
growth  as  occurring  at  a  not  less  constant  interval,  yet  experience  shows  that  these  inter- 
vals are  entirely  regulated  by  temperature :  for  if  one  of  the  ordinary  deciduous  trees  of 
temperate  climates  be  transferred  to  a  tropical  climate,  it  will  live  much  faster,  its  leaves 
being  shed  far  more  frequently,  and  being  replaced  much  more  speedily;  so  thnt  two,  or 
even  three,  successive  exuviations  and  reproductions  of  its  foliage  may  take  place  w:*hi«» 
a  year. 


332  OF    NUTRITION. 

346.  The  performance  of  the  function   of  Nutrition,  the  demand  for  which 
arises  out  of  the  causes  that  have  been  now  discussed,  is  dependent,  not  merely 
upon  a  due  supply  of  pure  and  well-elaborated  blood,  but  also  upon  the  normal 
condition  of  the  part  to  be  nourished,  and  especially  upon  its  possession  of  a 
right  measure  of  'formative  capacity;'  in  virtue  of  which,  the  newly-produced 
tissues  are  generated  in  the  likeness,  as  well  as  in  the  place,  of  those  which  have 
become  effete.     The  exactness  of  this  replacement  is  most  remarkably  shown  in 
the  retention  of  the  characteristic  form  and  structure  of  each  separate  organ  or 
part  of  the  body,  and  thus  of  the  entire  organism,  through  a  long  series  of  years ; 
no  changes  being  apparent  (so  long  as  the  state  of  health  is  preserved),  but  such 
as  are  conformable  to  the  general   type  of  that  alteration  which  the  organism 
undergoes  with  the  advance  of  life.     And  not  only  is  this  to  be  noticed  in  the 
conservation    of  all   those  distinguishing  points    of  structure  which  mark  the 
species,  and  are  essential  to  its  well-being;  but  it  is  still  more  remarkably  dis- 
played in  the  continuous  renewal  of  those  minor  peculiarities,  which  constitute 
the  characteristic  features  of  the  individual,  and  which  serve  to  distinguish  him 
from  his  fellows.     And  how  much  this  depends  upon  the  formative  capacity 
originally  derived  from  the  germ,  is  evident  from  this,  that  a  similar  moulding 
(so  to  speak)  of  the  nutritive  material  takes  place;  in  its  original  development,  at 
first  into  the  form  characteristic  of  the  species,  and  afterwards  into  that  which 
marks  the  individual;  and  that  the  peculiarities  of  the  individual  are  frequently 
such  as  have  been  distinctive  of  one  or  other  of  the  parents,  or  present  a  combi- 
nation of  both.     But  it  is  curious  that  the  formative  power  should  often  be  exer- 
cised, not  only  in  maintaining  the  original  type,  but  also  in  keeping-up  some 
acquired  peculiarity ;  as,  for  example,  in  the  perpetuation  of  a  cicatrix  left  aftei 
the  healing  of  a  wound.     For,  as  Mr.  Paget  has  remarked,  the  tissue  of  a  cica- 
trix grows  and  assimilates  nutrient  material,  exactly  as  do  its  healthy  neighbour- 
ing tissues ;  so  that  a  scar  which  a  child  might  have  said  to  be  as  long  as  his 
own  fore-finger,  will  still  be  as  long  as  his  fore-finger  when  he  becomes  a  man. 
And  when  the  mode  of  nutrition  in  any  part  has  been  altered  by  disease,  there 
is  frequently  an  obstinate  tendency  to  the  perpetuation  of  the  same  alteration ; 
or,  if  the  healthy  action  be  for  a  time  restored,  there  is  a  peculiar  tendency  to 
the  renewal  of  the  morbid  process  in  the  part;  and  this  is  stronger  the  more  fre- 
quently it  occurs,  until  at  last  it  becomes  inveterately  established.     There  is, 
however,  in  the  Tissues  generally,  as  in  the  Blood  (§  223),  a  general  tendency  to 
a  return  to  the  normal  type,  after  it  has  undergone  a  temporary  perversion ;  and 
thus  it  is,  that  we  find  the  typical  structure  of  parts  gradually  restored,  when 
the  morbid  tendency  has  been  overcome;  and  that  even  cicatrices  and  indura- 
tions, notwithstanding  their  usual  obstinate  persistence,  occasionally  disappear. 
The  normal  type  is,  perhaps,  less  likely  to  be  thus  recovered,  when  the  departure 
from  it  is  very  slight,  and  consists  rather  in  the  wrong  plan  (so  to  speak)  on 
which  the  new  matter  is  laid-down,  than  in  a  perversion  of  the  nutritive  process 
itself. 

347.  Of  the  mode  in  which  the  substitution  of  new  tissue  for  that  which  has 
become  effete,  is  effected  in  the  process  of  Nutrition,  our  knowledge  is  at  present 
limited ;  but  there  can  be  little  doubt  that  it  nearly  always   takes  place  in  a 
manner  closely  conformable  to  the  first  development  of  each  tissue.     In  some 
instances,  there  is  an  obvious  replacement  of  the  old  and  dead  by  the  young  and 
active  elements :  this  is  the  case,  for  example,  in  the  constantly-repeated  produc- 
tion of  the  Epidermic  and  Epithelial  layers;  for  whether  they  are  developed 
from  germs    imbedded  in   the    subjacent   basement-membrane,  or  from  nuclei 
formed  de  novo  in  the  blastema  on  its  free  surface,  or  by  the  duplicative  sub- 
division of  pre-existing  cells,  there  is  a  continual  succession  of  new  cells,  which 
take  the  place  of  those  that  are  cast-off  as  defunct  and  useless.     So  in  the  growth 
of  Hair,  the  increase  of  which  takes-place  only  at  its  base,  we  can  trace  at  any 
period  the  same  development  of  newly-formed  spheroidal  cells  into  horny  fusiform 


FORMATIVE    POWER    OF    INDIVIDUAL    PARTS.         333 

fibres,  as  that  which  occurred  when  first  the  hair  began  to  sprout  from  the  aggre- 
gation of  epidermic  cells  at  the  bottom  of  its  follicle.  So,  again,  in  the  vesicu- 
lar tissue  which  constitutes  the  essential  part  of  the  Nervous  centres,  there  are 
appearances  which  indicate  that  its  peculiar  cells  are  in  a  state  of  continual 
development,  newly-formed  ganglionic  vesicles  taking  the  place  of  those  which 
have  undergone  disintegration.  But  there  are  other  textures,  whose  nutrition  is 
more  completely  interstitial;  their  elements  being  more  closely  coherent,  and 
their  newly-formed  portions  being  developed  throughout  the  substance  of  the 
old,  instead  of  (as  in  the  case  of  the  epidermis  and  its  appendages)  superficially 
or  in  mere  continuity  with  it.  Such  is  the  case,  for  example,  with  Muscle,  the 
mode  of  whose  nutrition  has  not  yet  'been  elucidated.  We  can  only  infer  from 
analogy,  that  here  too  each  fibre  or  fibril  will  pass,  in  the  course  of  its  develop- 
ment, through  the  same  stages  which  those  of  the  embryo  did  when  its  muscles 
were  first  formed.  And  this  analogy  seems  to  derive  support,  from  the  presence, 
in  all  well-nourished  muscles,  of  bodies  which  bear  the  appearance  of  nuclei; 
for  these,  as  Mr.  Paget  remarks,  "  are  not  the  loitering  impotent  remains  of  em- 
bryonic tissue,  but  germs  or  organs  of  power  for  new  formation. "  And  it  is 
further  confirmatory  of  this  view,  that  losses  of  substance  of  muscle  which  in- 
volve the  destruction  of  these  centres  of  nutrition,  are  not  replaced,  like  losses 
of  cuticle,  by  new  tissue  of  the  same  kind  ;  the  power  to  form  it  not  being  in- 
herent in  the  blood  or  in  the  neighbouring  parts.  Nevertheless  it  must  be 
admitted  that  no  intermediate  stages  of  development  can  be  traced  in  the  fibres, 
even  of  those  muscles  of  the  adult  which  are  in  most  constant  use,  and  of  which 
the  nutrition  is  the  most  active,  that  are  at  all  comparable  to  those  which  are 
met-with  in  the  muscular  tissues  of  the  embryo. — With  regard,  again,  to  the  in- 
terstitial nutrition  of  Bones  and  Teeth,  we  know  nothing  whatever.  That  some 
movement  of  nutritive  fluid  is  continually  taking  place  through  them,  is  made 
apparent  by  the  effects  of  madder  in  gradually  tinging  even  the  bones  and  teeth 
of  the  adult,  though  for  such  a  change  a  much  longer  period  is  required  in  the 
adult  than  in  the  young  animal;  how  far  this  movement,  however,  is  subservient 
to  any  continual  change  of  substance,  still  remains  doubtful.  If  the  supply  of 
blood  be  withdrawn  from  a  tooth  or  from  a  bone,  or  even  from  a  part  of  the 
latter,  the  structures  thus  cut-off  from  connection  with  the  act  of  nutrition,  soon 
die,  become  detached  from  the  living  parts  around,  and  are  thrown-out  of  the 
body.  Of  this  we  have  a  very  good  example  in  the  annual  exuviation  of  the 
antlers  of  the  Deer,  which  is  brought-about  by  the  choking-up  of  the  Haversian 
canals  that  give  passage  to  blood-vessels,  with  concentric  osseous  deposit.  Some- 
thing of  this  kind  seems  to  be  continually  taking-place  in  ordinary  Bone,  upon  a 
more  limited  scale ;  individual  Haversian  systems  being  removed  by  absorption, 
and  being  replaced  by  new  formations  of  the  same  kind,  probably  during  its 
whole  life,  without  any  change  in  external  configuration  (§  348). 

348.  Of  the  modes  in  which  the  effete  particles  of  tissues  whose  term  of  life 
has  expired,  or  whose  vital  energy  has  been  exhausted,  are  removed  and  disposed- 
of,  our  present  knowledge  is  no  less  imperfect.  In  the  case  of  those  tissues  which 
are  superficially  nourished,  a  continual  loss  of  substance  is  obviously  taking- 
place,  by  the  exuviation  of  dead  particles  en  masse;  this  is  the  case  with  the 
whole  series  of  Epithelial  and  Epidermic  cells,  which  are  thrown-off  with  little 
previous  change,  like  the  leaves  of  trees,  their  decay  not  taking  place,  for  the 
most  part,  until  after  they  have  become  detached  from  the  organism.  But  the 
fact  is  altogether  different  with  regard  to  those  whose  nutrition  is  interstitial, 
especially  the  Nervous  and  Muscular  tissues;  for  the  decomposition  of  these 
would  seem  to  occur  in  their  very  substance,  its  products  being  taken-up  by  the 
blood,  and  subsequently  eliminated  from  it  by  organs  appropriated  to  that  pur- 
pose,  as  is  indicated  by  Chemical  evidence.  For  on  the  disintegration  of  the 
albuminous  constituent  of  Muscle,  it  appears  to  resolve  itself  into  two  classes  of 
compounds ;  one  of  them  rich  in  carbon,  the  other  in  nitrogen ;  the  former  is 


331 


OF    NUTRITION. 


represented  in  the  'juice  of  flesh'  (the  peculiar  ( extractive'  of  which  is  much 
increased  in  amount  by  exercise  of  the  muscle)  by  inosite  or  muscle-sugar,  by 
lactic  acid,  and  under  certain  conditions,  by  fat;  the  latter  by  creatine  and  crea- 
tinine.  The  former  class  of  products  is  taken-up  into  the  blood,  to  be  eliminated 
from  it,  partly  through  the  intermediation  of  the  liver,  by  the  respiratory  pro- 
cess ;  the  latter  is  in  like  manner  conveyed  by  the  circulating  current,  to  the 
kidneys,  the  creatine  being  for  the  most  part  converted  into  urea.  —  As  regards 
the  Nervous  substance,  however,  no  equally  definite  proof  of  this  kind  can  at 
present  be  afforded ;  since  its  normal  constitution  is  not  yet  sufficiently  under- 
stood, to  enable  the  products  of  its  disintegration  to  be  certainly  distinguished. 
— A  remarkable  indication  has  been  recently  afforded,  by  the  microscopic  exami- 
nation of  Bone,  that  the  older  portions  of  its  substance  are  removed  from  time 
to  time,  and  that  space  is  thus  provided  for  the  deposit  of  newly-formed  tissue, 
in  its  stead.  For  transverse  sections  of  long  bones  usually  exhibit,  in  some  part 
of  their  area,  irregularly-shaped  spaces,  having  an  emarginated,  festooned,  and 
often  jagged  outline  (Figs.  84,  85),  similar  to  that  found  on  the  surface  of  bone 


FIG.  84. 


FIG.  85. 


Transverse  section  of  compact  Bone,  showing  an  The  same,  from  a  less  compact  part 

Haversian  space,  a,  with  its  characteristic  emargi-  of  the  bone, 

nated  outline. 

which  has  been  removed  by  exfoliation,  or  to  that  of  the  fang  of  a  tooth  which 
has  been  partly  absorbed.  There  is  every  indication,  from  a  comparison  of  the 
various  conditions  presented  by  these  '  Haversian  spaces/  both  as  to  form,  size, 
and  situation,  that  they  are  left  by  the  partial  or  complete  removal  of  '  Haversian 
systems/  which  previously  occupied  the  same  situations.  They  are  exceedingly 
numerous  and  large  in  newly-formed  bone  situated  near  ossifying  cartilage,  so 
as  frequently  to  afford  room  for  the  development  of  two  or  more  '  Haversian 
systems'  in  their  interior;  while  in  older  bone  they  are  far  less  numerous,  and 
generally  less  in  size,  so  that  by  the  excavation  of  one  of  these  spaces  within  an 
old  l  Haversian  system/  a  new  one  may  be  formed  of  much  smaller  dimensions 
(Fig.  86,  c).  The  persistence  of  portions  of  those  older  '  Haversian  systems ' 
which  have  undergone  partial  absorption,  appears  to  account  for  the  presence  of 
the  'interstitial  laminae'  (6, 6), ,  which  fill-up  the  spaces  between  the  existing 
'  Haversian  systems/  and  of  which,  as  they  have  not  any  obvious  centres  of  nu- 
tritive supply,  no  other  satisfactory  explanation  can  be  given.  Such  appearances, 
indicative  of  alternate  acts  of  absorption  and  reproduction,  are  seen  in  the  bones 
of  old  as  well  as  of  young  or  middle-aged  subjects;  but  their  frequency  dimi- 


FORMATIVE    POWER    OF    INDIVIDUAL    PARTS.          335 

FIG.  86 


Transverse  section  of  compact  Bone,  showing  the  ordinary  appearances; — a,  Haversian  system  j 
b,  b,  interstitial  laminae;  c,  new  Haversian  system  within  an  older  one. 

nishes  with  the  increasing  age  of  the  individual.'  —  So  far  as  can  be  gathered 
from  the  foregoing  facts,  and  from  others  of  the  same  order,  the  process  of  in- 
terstitial decline  and  death  usually  takes  place  too  rapidly  for  its  stages  to  be 
perceptible,  and  is  immediately  followed,  in  the  normal  condition  of  the  system, 
by  the  removal  of  the  effete  particles ;  so  that  it  is  only  when  this  removal  is 
from  any  cause  obstructed,  as  happens  in  the  cases  to  be  presently  cited,  that  we 
see  any  indication  of  the  stages  through  which  the  disintegrating  tissues  pass.2 

349.  There  is  one  remarkable  form  of  degeneration,  however,  which  is  common 
to  nearly  all  the  tissues,  and  which  seems  to  occur  as  a  normal  alteration  in  many 
of  them  at  an  advanced  period  of  life  j  this  consists  in  the  conversion  of  their 
albuminous  or  gelatinous  materials  into  fat,  thus  constituting  what  is  known  as 
fatty  degeneration.  That  this  change  is  not  due  to  the  removal  of  the  normal 
components  of  the  tissues,  and  the  substitution  of  newly-deposited  fatty  matter 
in  their  place,  but  is  (in  most  cases  at  least)  the  result  of  a  real  conversion  of 
the  one  class  of  substances  into  the  other,  may  now  be  considered  as  well  ascer- 
tained.3 And  there  are  certain  facts  which  indicate  that  this  kind  of  degenera- 
tion is  a  part  of  the  regular  series  of  processes,  by  which  tissues  that  have  served 
their  purpose  in  the  economy  are  prepared  for  being  removed  by  absorption ;  one 
of  the  most  remarkable  being  the  observations  of  Virchow4  and  Kilian  5  with, 
regard  to  the  fatty  degeneration  of  the  muscular  tissue  of  the  uterus  after  partu- 
rition. So,  as  Mr.  Paget  has  pointed-out,  the  fibrinous  and  corpuscular  products 
of  inflammation  are  often  brought  into  a  state  fit  for  absorption,  by  passing 

1  See  the  Memoir  by  Messrs.  Tomes  and  De  Morgan  '  On  the  Structure  and  Develop 
ment  of  Bone,'  in  "  Philos.  Transact.,"  1853,  p.  111. 

3  Fully  recognizing  the  importance  of  Dr.  Lyon's  ingenious  enquiries  on  '  Histolysis ' 
(see  "Proceed,  of  Royal  Irish  Acad.,"  vol.  v.,  part,  iii.,  and  "Brit,  and  For.  Med.-Chir. 
Rev.,"  vol.  xii.,  pp.  454,  532),  the  Author  cannot  regard  the  changes  which  take  place  in 
tissues  decomposing  out  of  the  body,  as  throwing  much  light  upon  the  processes  of  dege- 
neration that  take  place  during  the  latter  period  of  their  life. 

3  For  a  very  complete  view  of  the  present  state  of  our  knowledge  of  the  whole  subject 
of  Fatty  Degeneration,  see  Dr.  Handfield  Jones's  Articles  in  the  "  Brit,  and  For.  Med 
Chir.  Rev.,"  vol.  xi.,  p.  327,  and  vol.  xii.  p.  30. 

*  "  Verhandlungen  der  Gesellschaft  fur  Geburtshiilfe,"  Berlin,  vol.  iii.  p.  xvi  . 

•  "  Henle  und  Pfeuffer's  Zeitschrift,"  vol.  ix.  p.  1. 


33(> 


OF   NUTRITION. 


through  this  intermediate  stage;  the  fibrinous  substance  being  observed  to  b« 
dotted  by  granules,  which  are  known  to  be  oil-particles  by  their  peculiar  shining 
Mack-edged  appearance,  and  at  the  same  time  losing  its  toughness  and  elasticity, 


[Fie.  87. 


and   being    no    longer  rendered    trans- 


Softening  fibrine  from  a  vein-clot.     The  dark 
points  are  minute  oil  drops.] 


parent  by  acetic  acid  (Fig.  87) ;  whilst 
the  lymph-cells  present  a  similar  in- 
crease of  shining  black-edged  particles 
like  minute  oil-drops,  which  accumulate 
until  they  nearly  fill  the  cell-cavity, 
their  nuclei  at  the  same  time  gradually 
fading  and  disappearing.1  Thus,  then, 
if  the  fat,  which  is  one  of  the  products 
of  this  regressive  metamorphosis,  be  ab- 
sor^e(^  as  ^ast  as  i*  ^s  formed,  and  the 
effete  tissue  be  replaced  by  a  new  pro- 
duction (as  seems  to  be  the  case  with 
Muscles  in  a  state  of  healthy  activity),  there  is  no  appearance  of  degeneration, 
and  the  nutrition  is  kept-up  to  its  normal  standard.  So  if,  from  the  advance  oi 
age,  or  from  the  insufficient  exercise  of  the  muscles,  their  nutrition  take  place 
less  rapidly  than  their  waste,  whilst  the  products  of  their  degeneration  are  still 
removed,  simple  atrophy  is  the  result.  If,  on  the  other  hand,  the  general  con- 
ditions being  similar,  the  fat  produced  in  degeneration  be  not  absorbed,  but 
remain  in  the  tissue,  an  obvious  '  fatty  degeneration  '  is  the  result.  This  seems 
most  likely  to  happen  either  (1)  when  the  fat  is  thus  produced  in  such  excessive 
amount,  that  the  ordinary  rate  of  its  absorption  (corresponding  with  that  of  its 
elimination  by  the  combustive  process)  does  not  provide  for  its  removal ;  which 
will  occur  when  a  large  amount  of  tissue  is  undergoing  degeneration  at  once,  as 
in  the  case  of  the  uterus  after  parturition : — or  (2)  when  the  blood,  being  already 
highly  charged  with  respiratory  material,  is  indisposed  to  receive  an  additional 
amount  of  fat;  and  it  is  probably  in  part  from  this  cause,  that  the  habitual  pre- 
sence of  Alcohol  in  the  blood  strongly  predisposes  to  fatty  degeneration,  as  is 
proved  by  the  very  large  proportion  of  intemperate  individuals  among  the  sub- 
jects of  the  more  aggravated  forms  of  this  disorder.  For  the  extraordinary 
aptitude  for  the  combustive  process  which  is  characteristic  of  Alcohol,  gives  it- 
such  a  preference  in  this  operation  over  the  ordinary  combustive  material,  that 
the  conversion  of  the  latter  by  oxidation  into  carbonic  acid  and  water  is  kept- 
back,  so  long  as  Alcohol  is  present;  and  thus  the  blood  of  drunkards  becomes  so 
highly  charged  with  fat,  that  it  might  be  itself  con- 
[Fra.  88.  ^  sidered  to  be  in  a  state  of  fatty  degeneration 2  (Fig.  88). 


This  distinct  indication  of  the  operation  of  Alcohol 
habitually  received  into  the  blood  in  large  quantities, 
affords  an  obvious  indication  that  the  habitual  consump- 
tion of  even  a  much  smaller  amount  will  tend  to  pro- 
duce fatty  degeneration  at  more  remote  periods  and  in  a 
less  aggravated  degree ;  and  the  participation  which  this 
state  has  been  shown  to  have  in  the  production  of  a 
large  proportion  of  the  diseases  of  Old  Age, — especially 
by  the  changes  it  induces  in  the  texture  of  the  heart 


Fat  in  Blood.] 


and  of  the  walls  of  the  blood-vessels  (which  are  particularly  liable  to  it), — fully 
bears-out  this  idea. 

1  See  Mr.  Paget's  "  Lectures  on  Surgical  Pathology." 

3  The  quantity  of  fat  in  the  blood  of  drunkards  has  been  found  in  some  cases  to  be  as 
much  as  117  parts  in  1000  (Lecanu),  the  highest  estimate  of  the  quantity  in  health  being 
8-65  parts.  Scharlau  has  found  as  much  as  30  per  cent,  more  carbon  in  the  blood  of  a 
drunkard,  than  in  that  of  a  healthy  man.  —  See  Dr.  Huss's  treatise  on  "  Alcoholisinus 
Chronicus,"  Rokitansky's  "  Handbuch  der  aligemeimen  pathologischen  Anatomic,"  band 
iv.,  and  "Brit,  and  For.  Med -Chir.  Rev.,  vol.  xii.,  pp.  33,  34. 


VARYING   ACTIVITY   OF   THE   NUTRITIVE   PROCESSES.  337 

350.  It  may  be  stated  as  a  general  rule,  that  no  absorption  of  the  materials 
of  tissues  can  take-place,  without  a  previous  degeneration  such  as  this,  or  a  more 
complete  decomposition.    There  is  no  evidence  that  any  healthy  tissue  is  ever  thus 
absorbed,  or  that  any  preternatural  activity  of  the  absorbent  vessels  can  ever  (as 
formerly  supposed)  be  the  occasion  of  a  loss  of  substance ;  in  fact,  so  long  as  the 
vital  force  is  in  active  operation  in  a  part,  and  its  processes  of  growth  and  deve- 
lopment are  being  normally  carried-on,  such  absorption  may  be  considered  to  be 
impossible.     On  the  other  hand,  if  a  part  die  en  masse,  it  is  not  removed  by  ab- 
sorption, but  becomes  isolated  by  the  separation  and  recedence  of  the  living  parts, 
and  is  then  cast-out  altogether,  even  from  the  interior  of  the  body,  as  we  see  in 
the  case  of  a  necrosed  bone;  its  condition  being  then  essentially  the  same  as  that 
of  the  outer  layers  of  the  tegumentary  organs,  which  are  cut-off,  by  their  distance 
from  a  vascular  surface,  from  all  further  nutrient  change.    The  difference  between 
these  two  modes  of  removal  is  well  seen  (as  Mr.  Paget  has  remarked)  in  the  case 
of  the  Teeth ;  for  the  fangs  of  the  deciduous  teeth  undergo  degeneration,  when 
the  current  of  nutrition  is  diverted  towards  those  which  are  to  succeed  them, 
their  materials  being  slowly  decomposed  so  as  to  become  soluble,  and  being  gra- 
dually removed  by  absorption,  so  that  nothing  is  left  at  last  but  the  crowns  of 
the  teeth ;  on  the  other  hand,  the  permanent  teeth,  which  are  not  to  be  succeeded 
by  others,  when  no  longer  receiving  their  due  nutrition,  die,  and  are  cast-out 
entire. 

351.  Among  the  conditions  of  healthy  Nutrition,  a  due  supply  of  Nervous 
power  is  commonly  enumerated ;  and  it  cannot  be  questioned  that  the  want  of 
such  a  supply  is  frequently  the  source  of  a  perversion  of  the  normal  operations. 
This,  however,  by  no  means  proves  that  the  formative  power  is  derived  from  the 
nervous  system ;  and  such  an  idea  is  at  once  negatived  by  a  number  of  incon- 
testible  facts  (§  33).     Yet  it  may  be  freely  admitted  that  the  right  direction  and 
application  of  this  power  in  Nutrition,  may  sometimes  depend  upon  guidance  and 
direction  afforded  by  the  Nervous  centres,  in  the  same  manner  as  the  Secreting 
process  is  capable  of  being  thus  affected ;  in  fact  we  can  scarcely  explain  in  any 
other  mode  that  influence  of  mental  states  upon  the  nutrient  operations,  which 
frequently  leads  to  very  important  modifications  of  them.  —  The  whole  of  this 
subject,  however,  will  be  more  appropriately  considered  hereafter  (CHAP,  xv).1 

2.    Varying  Activity  of  the  Nutritive  Processes. — Reparative  Operations. 

352.  Without  any  change  in  the  character  of  the  Nutritive  processes,  there 
may  be  considerable  variations  in  their  degree  of  activity ;  and  this,  as  regards 
either  the  entire  organism,  or  individual  parts,- though  most  commonly  the  latter. 
These  variations  may  be  so  considerable  as  to  constitute  Disease ;  though  there 
are  some  which  take  place,  as  part  of  the  regular  series  of  Physiological  pheno- 
mena.    Thus,  as  we  have  seen,  it  is  to  the  excess  of  formative  activity,  that  the 
increase  of  the  organism  in  the  earlier  period  of  life  is  due,  its  '  waste'  being  at 
the  same  time  extremely  rapid ;  whilst  it  is  to  a  corresponding  reduction  in  the 
regenerative  power,  and  not  to  positive  excess  of  'waste7  or  decay  (this,  indeed, 
taking  place  very  slowly),  that  the  gradual  decline  of  the  organism  in  advancing 
years  is  to  be  attributed.     So  also  we  find  that  local  as  well  as  general  variations 
may  take  place,  as  a  part  of  the  regular  series  of  vital  phenomena;  and  this 
during  the  period  of  adult  life,  as  well  as  in  the  earlier  and  later  epochs.     Thus 
all  those  differences  in  the  proportional  development  of  the  several  parts  of  the 
organism,  which  mark   the  distinction  between  the  adult  and  the  child,  even 
where  (as  in  the  case  of  a  dwarf),  there  is  no  difference  in  stature,  result  from  a 

1  In  the  treatment  of  this  subject,  the  Author  has  made  use  of  many  valuable  illustra- 
tions contained  in  the  first  three  of  Mr.  Paget's  "Lectures  on  Surgical  Pathology ;;'  the 
general  doctrines,  however,  being  such  as  he  had  himself  expressed  on  many  previous 
occasions. 

22 


338  OF   NUTRITION. 

decline  in  the  formative  capacity  of  those  which  are  peculiarly  adapted  to  the 
wants  of  the  earlier  stage  (the  Thymus  gland,  for  example),  and  from  an  increased 
activity  of  nutrition  in  those  which  are  destined  to  the  use  of  the  adult,  the 
Generative  organs  more  particularly.  And  the  intermittent  activity  of  the  sexual 
apparatus  of  the  female  affords  a  remarkable  example  of  the  same  principle ;  this 
being  marked,  not  merely  in  the  enormous  development  of  the  uterus  and  mam- 
mary glands  as  a  consequence  of  conception,  but  in  tlio  periodical  change  which 
takes  place  in  the  ovaries,  whereby  the  ova  are  matured  and  thrown-off  at  certain 
regular  intervals.  The  decline  in  the  formative  power  of  these  same  organs, 
moreover,  when  as  yet  the  organism  in  general  shows  but  little  indication  of  de- 
terioration, is  another  characteristic  example  of  the  variation  in  Nutritive  activity 
resulting  from  the  inherent  endowments  of  the  part,  and  essentially  irrespective 
of  the  condition  of  the  blood,  of  the  circulation,  and  of  the  organism  as  a  whole; 
although,  as  formerly  shown  (§  219),  the  production  and  maintenance  of  other 
and  apparently  unconnected  organs  are  comphmentally  dependent  upon  the  for- 
mative activity  of  the  Generative  apparatus. 

353.  The  abnormal  excess  of  Nutritive  change  which  properly  constitutes 
Hypertrophy,  appears  to  depend  upon  a  departure  from  one  or  other  of  the  con- 
ditions, under  which,  as  already  specified,  the  change  normally  takes  place; 
namely,  the  right  composition  of  the  blood,  a  due  supply  of  such  blood,  and  a 
proper  formative  capacity  in  the  part  itself. — Of  the  excess  of  nutrition  resulting 
from  the  presence  of  an  excess  of  the  peculiar  materials  of  certain  tissues  in  the 
circulating  fluid,  examples  have  already  been  given  (§  340) ;  it  is  important  to 
remark,  however,  that  although  hypertrophy  may  be  thus  induced  in  any  of  the 
tissues  which  constitute  the  instruments  of  organic  life,  yet  there  is  no  evidence 
that  either  the  Nervous  or  the  Muscular  apparatus  can  be  forced  (so  to  speak)  to 
an  augmentation  in  bulk,  by  the  mere  abundance  of  their  nutritive  materials. — 
With  regard,  in  the  next  place,  to  the  supply  of  blood,  there  can  be  no  doubt 
that  in  general  an  increased  flow  of  blood  towards  a  part  is  consequent-upon, 
ather  than  a  cause-of,  an  excess  in  its  nutritive  activity ;  but  still  there  are  cases 
in  which  its  causative  agency  may  be  traced.  Various  examples  of  this  have 
been  supplied  by  the  experiments  and  observations  of  John  Hunter,  the  records 
of  which  are  left  in  his  Museum.  Thus  if  the  spur  of  a  cock  be  transplanted 
from  the  leg  to  the  comb,  which  is  a  part  far  more  vascular  than  that  with  which 
it  was  originally  connected,  it  undergoes  an  extraordinary  augmentation  in  size ; 
having  in  one  instance  grown  in  a  spiral  form,  until  it  was  six  inches  long ;  and 
in  another,  curved  forwards  and  downwards  like  a  horn,  so  that  its  end  needed  to 
be  often  cut,  to  enable  the  bird  to  bring  its  beak  to  the  ground  in  feeding.  So, 
again,  it  was  remarked  by  Hunter,  and  has  been  frequently  observed  since,  that 
an  increased  growth  of  hair  often  takes  place  on  surfaces  to  which  there  is  an 
increased  determination  of  blood  as  a  consequence  of  inflammation  in  some  neigh- 
bouring part,  though  not  from  the  surface  of  the  inflamed  part  itself.  So  it 
sometimes  happens,  that  when  an  ulcer  of  the  integuments  of  the  leg  has  long 
existed  in  a  young  person,  the  subjacent  bone  may  share  in  the  increased  afflux 
of  blood,  and  may  enlarge  and  elongate.  And  it  seems  not  improbable  that  we 
are  to  attribute  the  increased  thickness  of  the  cuticle,  on  parts  which  are  exposed 
to  continual  pressure  or  friction,  to  the  augmented  afflux  of  blood  which  is  deter- 
mined to  the  irritated  surface.1 

354.  The  greater  number  of  cases  of  Hypertrophy,  however,  must  undoubt- 
edly be  referred  to  the  preternatural  formative  capacity  of  the  part  itself;  and 
this  may  either  be  congenital  or  acquired.  Of  this  congenital  excess,  we 
have  a  remarkable  example  in  the  abnormal  growth  of  an  entire  limb,  or  of 

1  It  is  commonly  said  that  local  Hypertrophy  may  be  induced  by  long-continued  Con- 
gestion :  but  this  is  not  true  hypertrophy ;  for  the  bulk  of  the  organ  is  not  augmented  by 
the  increased  production  of  its  normal  tissue,  but  by  the  addition  of  tissue  of  an  inferior 
type  of  organisation,  as  in  Inflammation  (|  869). 


HYPERTROPHY.  339 

fingers  or  toes,1  which  cannot  with  any  probability  be  referred  to  an  original 
excess  in  the  supply  of  blood,  the  enlargement  of  the  arteries  leading  towards 
such  parts  being  almost  certainly  consequent  upon  their  unusually  rapid  growth, 
just  as  in  the  case  of  the  uterine  and  mammary  arteries  of  the  pregnant  female. 
The  most  remarkable  instances  of  the  acquirement  of  increased  formative  ac- 
tivity, are  represented  to  us  in  that  augmented  growth  of  the  nervous  and  mus- 
cular tissues,  which  is  consequent  upon  the  exercise  of  their  functional  powers. 
This  may  be  considered  as  to  a  certain  extent  a  normal  adjustment  of  the  supply 
to  the  demand ;  but  there  are  some  instances  in  which  it  takes  place  to  such  an 
extent,  as  to  become  a  positive  disease.  Thus  it  not  unfrequently  happens,  that 
if  young  persons  who  naturally  show  precocity  of  intellect,  are  encouraged  rather 
than  checked  in  the  use  of  the  brain,  the  increased  nutrition  of  the  organ  (which 
grows  faster  than  its  bony  case)  occasions  pressure  upon  its  vessels,  it  becomes 
indurated  and  inactive,  and  fatuity  and  coma  may  supervene.  Now  although  in 
such  cases  there  must  probably  have  been  some  congenital  tendency  to  preter- 
natural activity  of  the  brain,  which  manifests  itself  in  the  precocity  of  intellect, 
yot  there  is  no  doubt  that  this  may  be  augmented  by  the  'forcing  system'  of 
education  ;  whilst,  on  the  other  hand,  it  may  be  controlled  by  a  system  of  manage- 
ment adapted  to  the  peculiar  circumstances  of  the  case.  Excess  of  muscular 
•development  is  peculiarly  prone  to  show  itself  in  the  in  voluntary 'muscles;  but 
this  production  is  in  almost  every  instance  the  result  of  the  demand  for  increased 
muscular  exertion,  which  is  consequent  upon  some  obstruction  to  the  usual  func- 
tion of  the  part.  Thus  an  extraordinary  hypertrophy  of  the  muscular  coat  of 
the  urinary  bladder  is  often  seen  as  a  consequence  of  obstruction  to  the  exit  of 
the  urine,  through  the  presence  of  a  stone  in  the  bladder  or  of  a  stricture  in  the 
urethra;  so  again,  hypertrophy  of  the  muscular  coat  of  the  gall-bladder  may 
take-place  as  a  consequence  of  obstruction  of  its  duct  by  a  gall-stone ;  hyper- 
trophy of  the  muscular  coat  of  any  part  of  the  alimentary  canal  may  be  induced 
by  the  existence  of  stricture  lower  down ;  and  even  hypertrophy  of  the  heart  is 
generally,  if  not  always,  attributable  to  obstruction  to  the  exit  of  the  blood 
which  it  propels,  resulting  either  from  stagnation  of  the  pulmonary  circulation 
by  the  deficient  aeration  consequent  upon  disease  of  the  lungs  (in  which  case 
the  hypertrophy  is  limited  to  the  right  side  of  the  heart),  or  from  thickening  or 
induration  of  the  semilunar  valves,  or  from  narrowing  of  the  orifices  of  the  aorta 
and  pulmonary  artery.  It  is  curious,  moreover,  to  observe  that  hypertrophy  of 
muscles  frequently  becomes  a  source  of  increased  nutrition  of  the  bones  to  which 
they  are  attached :  this  being  manifested,  not  merely  in  the  augmented  bulk  of 
the  bones  of  limbs  that  are  specially  exercised,  but  also  in  the  increased  promi- 
nence of  the  ridges  and  processes  to  which  the  muscles  are  attached.  This  adap- 
tiveness  on  the  part  of  the  formative  activity  of  the  osseous  tissue,  is  curiously 
manifested  also  in  the  relation  of  the  skull  to  the  brain ;  for  if  the  bulk  of  the 
•  brain  be  not  too  rapidly  augmented,  the  skull  will  enlarge  accordingly,  and  this 
(in  some  instances)  not  merely  by  the  extension  of  its  normal  bones,  but  by  the 
intercalation  of  new  osseous  elements,  the  'ossa  wormiana;'  whilst,  on  the  other 
hand,  if  there  be  a  diminution  in  the  bulk  of  the  brain,  the  cranium  may  adapt 
itself  to  this  also,  by  a  thickening  on  its  internal  surface  (or  concentric  hyper- 
trophy),—  this  change,  rather  than  a  diminution  in  the  entire  substance  of  the 
skull,  being  more  liable  to  take  place  in  cases  in  which  the  cranial  sutures  have 
already  closed,  and  the  nutrition  of  the  bone  has  become  inactive. 

355.  The  production  of  Tumours  must  be  considered  as  a  manifestation  of  an 
excess  of  formative  activity  in  individual  parts,  and  as  constituting,  therefore,  a 
species  of  Hypertrophy.  For  a  tumour  may  be  composed  of  the  tissues  which 
are  normal  to  the  part;  as  we  see  especially  in  the  case  of  those  tumours  ef  the 

1  A  case  of  hypertrophy  of  an  entire  limb  was  described  by  Dr.  John  Reid  in  his 
"Edinb.  Monthly  Journ.,"  1843,  p.  198;  and  several  cases  of  hypertrophy  of  the  fingers 
were  described  by  Mr.  Curling  in  the  "  Med.-Chir.  Trans.,"  vol.  xxviii. 


340  OF    NUTRITION. 

uterus,  which  are  made-up  of  an  excess  of  its  ordinary  muscular  and  fibrous  ele- 
ments. But,  as  Mr.  Paget  has  justly  remarked,  "  an  essential  difference  lies  in 
this ; — the  uterus  (often  itself  hypertrophied)  in  its  growth  around  the  tumour 
maintains  a  normal  type,  though  excited  to  its  growth,  if  we  may  so  speak,  by 
an  abnormal  stimulus ;  it  exactly  imitates,  in  vascularity  and  muscular  develop- 
ment, the  pregnant  uterus,  and  may  even  acquire  the  like  power;  and  at  length, 
by  contractions  like  those  of  parturition,  may  expel  the  tumour  spontaneously 
separated.  But  the  tumour  imitates  in  its  growth  no  natural  shape  or  construc- 
tion ;  the  longer  it  continues,  the  greater  is  its  deformity.  Neither  may  we 
overlook  the  contrast  in  respect  of  purpose,  or  adaptation  to  the  general  welfare 
of  the  body,  which  is  as  manifest  in  the  increase  of  the  uterus  as  it  is  improbable 
in  that  of  the  tumour."1  A  gradation  is  established,  however,  between  true 
Hypertrophies  aud  Tumours,  by  those  productions  of  glandular  tissue,  which  are 
made-up  of  the  proper  substance  of  the  gland  with  which  they  are  connected,  as 
the  mammary,  the  prostate,  or  the  thyroid,  and  which  (though  frequently  en- 
cysted) are  sometimes  met-with  as  outlying  portions  of  the  gland  itself.  —  There 
is  another  class  of  objects,  to  which  Tumours  come  into  close  relation,  and  which 
must  be  referred,  like  them,  to  a  local  excess  of  formative  activity ;  these  are 
the  "  supernumerary  parts"  which  are  not  unfrequently  developed  during  fetal 
life,  as  for  example,  additional  finger  and  toes.  It  seems  absurd  to  refer  these, 
formed  as  they  are  by  simple  outgrowth  from  the  limbs  to  which  they  are  attached, 
to  the  ''fusion  of  germs"  which  has  been  hypothetically  invoked  to  explain 
more  important  excesses,  as  those  of  additional  limbs,  double  bodies,  or  double 
heads ;  and  yet  from  the  lower  to  the  higher  form  of  excess,  the  transition  is  so 
gradual,  that  what  is  true  of  the  former  can  scarcely  but  be  true  of  the  latter. 
Hence  even  complete  "  double  monsters"  must  be  regarded,  not  as  having  pro- 
ceeded from  two  separate  germs  which  have  become  partially  united  in  the  course 
of  their  development,  but  from  a  single  germ,  which,  being  possessed  of  an 
unusual  formative  capacity,  has  evolved  itself  into  a  structure  containing  more 
than  the  usual  number  of  parts,  and  comparable  to  that  which  may  be  artificially 
produced  by  partial  fission  of  the  bodies  of  many  of  the  lower  animals.2 

356.  We  can  scarcely  fail  to  recognize,  throughout  this  whole  series  of  abnor- 
mal productions,  the  operation  of  a  similar  power.  In  the  formation  of  a  super- 
numerary part,  this  has  been  sufficient,  not  merely  to  produce  the  tissues,  and  to 
develope  them  according  to  a  regular  morphological  type,  but  to  impart  to  the 
fabric  thus  generated  a  separate  and  even  an  independent  existence;  thus 
evolving  an  additional  finger  or  thumb  on  each  hand,  a  double  pair  of  arms  or 
legs,  a  double  head  or  trunk,  or  even  a  complete  double  body.  In  the  hyper- 
trophy of  a  regular  or  normal  part,  the  new  tissues  are  still  developed  according 
to  a  regular  morphological  type ;  but  they  have  not  the  power  of  individualizing 
themselves  (so  to  speak),  and  are  so  incorporated  with  the  normal  elements  as  to 
augment  the  size  of  the  existing  organ.  In  the  formation  of  a  tumour,  on  the. 
other  hand,  whilst  its  component  tissues  are  themselves  perfectly  formed,  and 
have  a  marked  power  of  independent  growth,  the  mass  composed  of  them  is  al- 
together amorphous,  its  configuration  being  usually  determined  rather  by  the 
physical  conditions  under  which  it  is  produced,  than  by  any  peculiar  tendencies 
of  its  own ;  so  that  we  recognize  the  action  of  the  formative  power,  undirected 
by  that  morphological  nisus,  which  normally  models  (so  to  speak)  the  growing 
tissues  into  the  likeness  of  the  organ  to  which  they  belong.  But  further,  in 
many  of  the  large  class  of  tumours  distinguished  as  'malignant'  (§  378),  the 

1  See  his  "  Lectures  on  Surgical  Pathology,"  p.  319,  Am.  Ed.  :  also  Dr.  Handfield  Jones  in 
"Brit,  and  For.  Med-Chir.  Rev.,"  vol.  xiii.  p.  330;  and  Dr.  Bristowe  in  "Trans,  of 
Pathol.  Soc.,"  vol.  iv.,  p.  218. 

3  See  "Princ.  of  Comp.  Phys.  Am.  Ed.,"  g  475;  Prof.  Vrolik  in  "Cyclop,  of  Anat.  and 
Phys.,"  art.  'Teratology,'  vol.  iv.  p.  976;  and  Prof.  Allen  Thomson  on  'Double  Monstros- 
ity,' in  "  Edinb.  Monthly  Tournal,"  June  and  July,  1844. 


ATROPHY.  341 

development  of  tissue  has  not  gone  to  the  extent  of  producing  any  of  those  spe- 
cies of  which  the  body  is  normally  constituted ;  and  in  this  respect,  as  well  as  in 
their  tendency  to  rapid  degeneration,  the  vital  endowments  of  their  elements 
must  be  reckoned  as  below  those  of  the  normal  tissues. — It  is  not  always  easy  to 
draw  the  line  between  certain  tumours  and  supernumerary  parts,  especially  when 
the  production  of  the  former  is  symmetrical  j  but  the  first  appearance  of  the 
latter  never  takes  place  save  during  embryonic  life,  and  their  structure  is  more 
complex,  and  is  more  conformed  to  the  plan  and  construction  of  the  body  at 
large,  than  is  that  of  tumours,  whose  production  may  take  place  at  any  period  of 
life.  And  between  those  tumours  which  are  known  as  'piliferous'  and  denti- 
gerous  cysts/  and  those  encysted  embryoes  (usually  incomplete  in  their  forma- 
tion) which  are  sometimes  found  in  the  bodies  even  of  males,  it  is  impossible  to 
establish  any  line  of  demarcation  sufficiently  precise,  to  prevent  our  recognizing 
them  as  all  having  the  same  origin,  and  being  expressions  of  the  same  power,  — 
the  simple  cyst  being  a  kind  of  rude  attempt  at  the  production  of  a  distinct  indi- 
vidual, —  and  the  encysted  embryo  being  but  the  result  of  an  unusually  high 
development  of  a  proliferous  cyst. 

357.  The  state  of  Atrophy  is  in  all  respects  the  very  opposite  of  that  of  Hy- 
pertrophy; consisting  in  such  a  reduction  in  the  rate  of  formative  activity  of 
parts,  as  compared  with  that  of  their  '  waste/  that  their  nutrition  is  no  longer 
maintained  at  its  previous  standard;  so  that  they  are  gradually  reduced  in  bulk, 
or  degenerate  into  some  inferior  histological  type,  or  (which  is  more  common) 
undergo  both  diminution  and  deterioration  at  the  same  time.  It  is  important  to 
bear  in  mind,  that  Atrophy  may  take-place,  either  locally  or  generally,  from  an 
unusually-rapid  disintegration  of  the  tissues,  uncompensated  by  a  corresponding 
increase  in  the  rate  of  their  nutrition :  of  such  local  atrophy,  we  have  a  charac- 
teristic example  in  the  rapid  reduction  of  the  bulk  of  the  uterus  after  parturi- 
tion, and  of  the  mammary  glands  after  the  sudden  cessation  of  lactation ;  of  the 
general,  we  see  an  illustration  in  that  rapid  wasting  of  the  system,  which  takes 
place  in  the  irritable  state  that  results  from  excessive  and  prolonged  exertion  of 
body  or  anxiety  of  mind,  especially  when  accompanied  with  want  of  sleep,  the 
increased  disintegration  being  marked  by  the  presence  of  an  unusual  amount  of 
urea  and  of  the  alkaline  phosphates  in  the  urine.  But  in  the  ordinary  forms  of 
Atrophy,  there  is  not  merely  a  relative  but  an  absolute  reduction  in  the  rate  of 
the  formative  process,  or  a  lowering  of  its  standard  of  perfection;  and  here  also 
we  have  to  look  for  its  causes,  on  the  one  hand,  in  the  condition  and  supply  of 
the  blood,  and,  on  the  other,  in  the  formative  capacity  of  the  tissues  themselves. 
—  The  Atrophy  dependent  upon  an  insufficient  supply  of  nutritive  materials, 
may  be  either  general  or  partial.  General  atrophy,  or  emaciation,  is  a  necessary 
result  of  deficiency  of  food :  but  it  may  also  proceed  from  an  imperfect  perform- 
ance of  the  assimilating  processes,  whereby  the  nutritive  materials  do  not  receive 
their  requisite  elaboration,  as  in  cases  of  disease  of  the  mesenteric  glands ;  or 
from  an  unusual  energy  of  the  metamorphic  processes,  whereby  the  azotized  con- 
stituents of  the  food  are  decomposed  into  excrementitious  products,  without  un- 
dergoing assimilation  at  all,  as  seems  to  be  the  case  in  diabetes.  Of  the  atrophy 
of  a  particular  tissue,  consequent  upon  the  deficiency  of  its  proper  materials  in 
the  blood,  we  have  an  example  in  the  reduction  of  the  adipose,  when  there  is  no 
surplus  of  fatty  matter  to  serve  for  its  nutrition,  but  on  the  other  hand  a  with- 
drawal of  the  contents  of  the  fat-cells  into  the  circulating  current,  whilst  the 
nutrition  of  the  muscular  and  other  azotized  tissues  may  proceed  with  its  usual 
vigour. — Instances  of  complete  local  atrophy,  or  gangrene,  resulting  from  deficiency 
in  the  supply  of  blood  to  a  part,  are  by  no  means  unfrequent;  but  it  is  less 
common  to  meet  with  a  prolonged  diminution  in  the  rate  of  nutrition  from  such 
a  cause,  since  a  partial  obstruction  to  the  circulation  is  usually  removed  after  a 
short  time  by  the  enlargement  of  the  collateral  vessels.  Yet  there  are  peculiar 
circumstances  under  which  this  does  not  take  place ;  thus  Mr.  Curling  has  shown 


342  OF    NUTRITION. 

that  atropby  may  occur  in  that  portion  of  a  fractured  bone  which  is  cut-off  from 
the  direct  supply  of  blood  through  the  great  medullary  artery ;  the  circulation 
being  restored  by  anastomosis  to  such  an  extent  as  to  prevent  the  death  of  the 
bone,  but  not  so  completely  as  to  support  vigorous  nutrition.1 

358.  The  most  frequent  cause  of  Atrophy  lies,  however,  in  the  deficiency  of 
formative  power  in  the  tissues  themselves,  arising  from  the  decline  of  that  capa- 
city which  they  inherit  from  the  germ.  This  decline,  as  already  shown,  takes 
place  in  the  body  at  large,  as  a  part  of  the  regular  order  of  things,  with  the  ad- 
vance of  years,  and  also  normally  occurs  in  particular  organs  at  earlier  periods 
of  life ;  but  it  sometimes  takes  place  prematurely,  either  in  the  body  at  large,  or 
m  particular  organs,  so  that  they  undergo  a  wasting  or  degeneration  without  any 
ostensible  cause.  Thus  it  is  not  at  all  uncommon  for  Articular  Cartilages  to  be 
almost  entirely  destroyed  through  defect  of  nutrition,  without  any  pain  or  other 
symptoms  to  call  attention  to  the  change  in  progress ; 2  and  many  similar  cases 
might  be  cited.  There  is  reason  to  believe  that  f  fatty  degeneration/  the  form 
under  which  degeneration  most  commonly  presents  itself  (§  349),  is  in  reality 
far  more  frequent  than  simple  wasting;  but  it  attracts  less  notice,  because  the 
bulk  of  the  tissues  is  little  or  not  at  all  diminished;  and  it  is  only  when  their 
function  becomes  impaired,  that  attention  is  seriously  drawn  to  the  change.  This 
form  of  Atrophy  can  seldom  be  attributed  to  antecedent  diminution  in  functional 
activity;  for  it  is  most  common  in  organs  upon  which  there  is  the  most  constant 
demand  for  the  energetic  performance  of  their  respective  duties,  as,  for  instance, 
in  the  heart,  the  kidneys,  and  the  liver.  But  the  formative  activity  of  Muscles 
and  Nerves  is  so  closely  dependent,  as  already  several  times  pointed-out,  upon 
the  active  exercise  of  their  functional  powers,  that  atrophy  is  certain  to  supervene 
if  this  be  interrupted ;  and  this  atrophy  may  or  may  not  present  itself  under  the 
form  of  fatty  degeneration ;  a  shrinkage  of  the  parts,  concurrently  with  the  pro- 
duction of  an  increased  amount  of  fat  in  them,  being  perhaps  the  mode  in  which 
it  most  frequently  takes  place.  Atrophy  of  one  part,  moreover,  may  be  dependent 
upon  atrophy  or  imperfect  functional  activity  of  another,  if  the  two  be  so  related 
in  their  normal  functions,  that  a  decline  of  one  involves  a  corresponding  decline 
in  the  other.  Thus  if  a  motor  nerve  be  paralyzed,  the  muscles  which  it  habitually 
calls  into  action  will  be  atrophied;  and  this  will  equally  happen,  whether  the 
want  of  motor  power  depend  upon  a  deficient  production  of  it  in  the  nervous 
centres,  or  upou  an  interruption  to  its  conduction  through  the  trunks.3  On  the 
other  hand,  if  the  muscles  of  a  part  undergo  degeneration  from  want  of  use  (as 
in  disease  of  the  hip-joint),  the  nerves  which  supply  them  also  suffer.  The  same 
is  the  case  in  regard  to  the  nerves  and  organs  of  sense :  for  atrophy  of  the  eye 
will  occasion  atrophy  of  the  optic  nerve,  and  destruction  of  the  optic  ganglia  will 

1  "  Medico-Chirurgical  Transactions,"  vol.  xx. 

2  See  Redfern,  "  On  Anormal  Nutrition  in  Articular  Cartilages,"  p.  65. 

3  The  Author  has  for  some  time  had  under  his  observation  a  case  in  which  three  males 
of  a  family  have  progressively  become  affected,  between  the  ages  of  3  and  5  years,  with 
fatty  degeneration  of  the  muscles,  which  has  proceeded  in  the  most  advanced  case  to  the 
almost  complete  obliteration  of  their  normal  structure.     This  change  had  been  considered 
by  many  eminent  Practitioners  to  be  idiopathic,  that  is,  to  have  its  primary  origin  in  the 
muscular  tissue;  and  the  measures  which  had  been  employed  to  arrest  it  had  been  of  no 
avail  whatever.    It  was  a  strong  argument,  however,  against  such  a  view  of  the  case,  that, 
in  the  heart  of  the  eldest  son,  who  died  of  fever  at  the  age  of  16,  no  fatty  degeneration 
cuuid  be  discovered:  and  on  making  inquiry  into  the  history  of  the  parents  and  of  their 
families,  ample  evidence  was  discovered  for  the  belief,  that  the  disease  was  dependent 
upon  the  want  of  functional  power  in  the  nervous  centres.     Acting  on  this  view,  it  was 
recommended  that  the  muscular  system  should  be  kept  as  much  as  possible  in  a  state  of 
active  exercise,  and  that  a  weak  galvanic  current  should  be  frequently  transmitted  through 
the  limbs  from  the  spine.     This  treatment  has  proved  so  far  successful,  that  the  progress 
of  the  disease  appears  to  have  been  arrested  in  the  most-advanced  case,  whilst  a  decided 
improvement  has  taken  place  in  the  condition  of  a  younger  child,  who  was  previously 
passing  rapidly  into  a  state  resembling  that  of  his  elder  brothers. 


ATROPHY.  343 

induce  atrophy  of  the  eyes  and  optic  nerves.  Even  the  bones  of  a  limb  will 
suffer,  in  cases  of  atrophy  of  the  muscles  consequent  upon  disuse  :  for  in  an  ex- 
periment made  by  Dr.  J.  Reid,  to  determine  the  effect  of  artificial  exercise  in 
maintaining  the  nutrition  of  muscles  whose  nerves,  had  been  divided,  the  bones 
of  the  quiescent  limb  only  weighed  81  grains,  whilst  those  of  the  exercised  limb 
weighed  89  grains.1 — It  is  an  important  fact,  which  was  first  pointed-out  by  Mr. 
Paget,2  that  when  fatty  degeneration  is  commencing  in  any  tissue,  which  is  cha- 
racterized by  the  persistence  of  its  nuclei,  it  is  in  the  nuclei  that  the  first  altera- 
tions are  seen ;  for  they  become  pale  and  indistinct,  and  may  even  disappear 
altogether,  almost  before  any  other  change  is  discernible  in  the  contents  of  the 
cells  or  tubes  to  which  they  appertain ;  but  in  atrophy  from  mere  decrease,  this 
disappearance  of  the  nuclei  does  not  occur. 

359.  Reparative  Process. — The  nutritive  operations  take  place  with  extraordi- 
nary energy  and  rapidity,  in  the  process  of  Reparation;  by  which  losses  of 
substance,  occasioned  by  injury  or  disease,  are  made  good.  In  its  most  perfect 
form,  this  process  is  exactly  analogous  to  that  of  the  first  development  of  the 
corresponding  parts  ;  and  its  results  are  as  complete  in  the  one  case  as  in  the 
other.  In  fact,  among  the  lowest  tribes  of  Animals,  we  find  these  two  conditions 
blended,  as  it  were,  together;  for  the  process  of  reparation  may  be  carried  in 
them  to  such  an  extent,  as  to  reproduce  the  whole  organism  from  a  very  small 
portion  of  it.  In  the  Hydra,  or  Fresh-water  Polype,  there  would  seem  to  be 
scarcely  any  limit  to  this  power;  for,  even  if  the  body  of  the  animal  be  minced 
into  small  fragments,  every  one  of  these  can  produce  a  new  and  perfect  being. 
In  this  manner,  no  less  than  forty  have  been  artificially  generated  from  a  single 
individual.  —  In  ascending  the  Animal  scale,  we  find  this  reparative  power  less 
conspicuous,  because  limited  in  its  exercise  to  particular  tissues  and  to  compara- 
tively insignificant  parts  of  the  body;3  and  in  Man,  as  in  other  warm-blooded 
Vertebrata,  the  regenerative  power  is  for  the  most  part  restricted  in  its  exercise, 
as  Mr.  Paget  has  pointed-out,4  to  three  classes  of  parts ; — namely,  (1).  "  Those 
which  are  formed  entirely  by  nutritive  repetition,  like  the  blood  and  epithelia 
(their  germs  being  continually  generated  de  novo  in  the  ordinary  condition  of  the 
body) ;  (2).  Those  which  are  of  lowest  organization,  and  (what  seems  of  more 
importance)  of  lowest  chemical  character,  as  the  gelatinous  tissues,  the  areolar 
and  tendinous,  and  the  bones;  (3).  Those  which  are  inserted  in  other  tissues, 
not  as  essential  to  their  structure,  but  as  accessories,  as  connecting  or  incorpo- 
rating them  with  the  other  structures  of  vegetative  or  animal  life,  such  as  nerve- 
fibres  or  blood-vessels.  With  these  exceptions,  injuries  or  losses  are  capable  of 
no  more  than  repair  in  its  limited  sense ;  i.  e.  in  the  place  of  what  is  lost,  some 
lowly-organized  tissue  is  formed,  which  fills  up  the  breach,  and  suffices  for  the 
maintenance  of  a  less  perfect  life.7'  —  Yet,  even  thus  restricted,  the  operations 
of  this  power  are  frequently  most  remarkable ;  and  are  in  no  instance,  perhaps, 
more  strikingly  displayed,  than  in  the  re-formation  and  remodelling  of  an  entire 
Bone,  when  the  original  one  has  been  destroyed  by  disease.  That  this  power  is 
intimately  related  to  that  by  which  the  organism  is  normally  built-up  and  main- 
tained, is  evident,  not  merely  from  the  peculiar  mode  in  which  it  is  exercised, — 
its  tendency  being  always  to  reproduce  each  part  in  the  form  and  structure  cha- 
racteristic of  it  at  the  particular  period  of  life,  and  not  according  to  its  embryonic 
type, — but  also  from  the  fact  that  it  is  more  effectual  in  the  state  of  growth  than 
in  the  adult  condition,  and  that  it  can  do  far  more  in  the  embryonic  state,  when 
development  as  well  as  growth  is  taking  place,  than  after  the  developmental  pro- 
less  has  ceased.  In  fact,  as  Mr.  Paget  has  remarked  (loc.  cit.),  its  amount  at 

1  "  Physiological,  Anatomical,  and  Pathological  Researches,"  p.  10. 

3  "  Lectures  on  Surgical  Pathology,"  p.  80,  Am.  Ed. 

8  See  "  Princ.  of  Comp.  Phys.,"  Chap,  xi.,  Sect.  3,  Am.  Ed. 

4  Op.  cit.  p.  115,  Am.  Ed. 


344  OF    NUTRITION. 

different  periods  of  existence,  as  in  different  classes  of  animals,  seems  to  bear  an* 
inverse  ratio  to  the  degree  of  development  which  has  already  taken  place.  Thus 
it  is  well  known  to  every  Practitioner,  how  much  more  readily  and  perfectly  the 
lesions  resulting  from  accident  or  disease  are  repaired  in  childhood  and  youth, 
than  they  are  after  the  attainment  of  the  adult  state.  And  there  is  evidence 
that  during  embryonic  life,  the  regeneration  of  lost  parts  may  take  place  in  a 
degree  to  which  we  have  scarcely  any  parallel  after  birth  :  for  Prof.  Simpson  has 
brought-together  numerous  cases,  in  which,  after  <  spontaneous  amputation'  of 
the  limbs  of  a  foetus,  occurring  at  an  early  period  of  gestation,  there  has  obviously 
been  an  imperfect  attempt  at  the  re-formation  of  the  amputated  part  from  the 
stump;1  and  it  seems  probable,  from  the  history  of  normal  development,  that  in 
the  cases  in  which  perfect  hands  and  feet  have  been  present  without  the  corre- 
sponding limbs,  these  hands  and  feet  have  been  secondary  productions  from  the 
stumps  of  amputated  limbs,  since  any  original  defect  of  development  would  have 
affected  the  hands  and  feet  rather  than  the  arms  and  legs.  There  are  occasional 
examples,  moreover,  in  which  this  regenerative  power  has  been  prolonged  to  an 
unusually  late  period ;  thus  an  instance  is  recorded,  on  authority  that  can  scarcely 
be  doubted,  of  the  twice-repeated  reproduction  of  a  supernumerary  thumb,  after 
it  had  been  twice  completely  removed ; 2  and  the  Author  has  been  assured  by  a 
very  intelligent  Surgeon,  that  he  was  cognizant  of  a  case  in  which,  the  whole  of 
one  ramus  of  the  lower  jaw  having  been  lost  by  disease  in  a  young  girl,  the  jaw 
had  been  completely  regenerated,  and  teeth  were  developed  and  occupied  their 
normal  situations  in  it. 

360.  It  has  been  a  general  opinion  among  British  surgeons  (founded  upon 
what  they  believe,  but  erroneously,  to  have  been  the  doctrine  of  Hunter),  that 
Inflammation  is  essential  to  the  process  of  Reparation.     There  is  no  doubt  that, 
as  usually  conducted,  the  healing  of  wounds  is  attended  by  a  greater  or  less  de- 
gree of  Inflammation;  but  it  does  not  thence  follow  that  this  morbid  condition 
is  essential  to  the  renewal  of  the  healthy  state ;  and  in  fact  it  can  be  shown  that, 
in  the  majority  of  cases,  the  occurrence  of  Inflammation  is  injurious  rather  than 
beneficial.     It  was  by  Dr.  Macartney,  that  the  first  clear  enunciation  of  this  im- 
portant truth  was  made ;  and  his  conclusions,  founded  upon  a  philosophical  com- 
parative survey  of  the  operations  of  Reparation  and  Inflammation,  as  performed 
in  the  different  classes  of  animals, — namely,  "  that  the  powers  of  reparation  and 
reproduction  are  in  proportion  to  the  indisposition  or  incapacity  for  inflammation ; 
— that  inflammation  is  so  far  from  being  necessary  to  the  reparation  of  parts, 
that,  in  proportion  as  it  exists,  the  latter  is  impeded,  retarded,  or  prevented  ; — 
that,  when  inflammation   does  not  exist,  the  reparative  power  is  equal  to  the 
original  tendency  to  produce  and  maintain  organic  form  and  structure ; — and  that 
it  then  becomes  a  natural  function,  like  the  growth  of  the  individual,  or  the 
reproduction  of  the  species/'3  —  may  be  regarded  as  substantially  correct,  al- 
though requiring  some  modification  in  particular  cases. 

361.  The  simplest  of  all  the  methods   of  healing  an  open  wound,  is  that 
which  is  termed  by  Dr.  Macartney  '  immediate  union.'     It  is  often  seen  in  the 
case  of  small  incised  wounds,  such  as  cuts  of  the  fingers,  or  the  incision  made  in 
venesection,  in  which  the  two  edges  can  be  brought  into  close  approximation,  so 
that  they  grow-together  without  any  connecting  medium  of  blood  or  lymph ;  but 
it  sometimes  occurs  in  larger  ones,4  and  as  it  is  the  best  imaginable  process,  the  ! 

1  These  cases  were  brought  by  Prof.  Simpson  before  the  Physiological  Section  of  the  ' 
British  Association,  at  its  Meeting  in  Edinburgh,  Aug.  1850.     The  Author,  having  hal 
ihe  opportunity  of  examining  two  living  examples,  as  well  as  Prof.  Simpson's  prepara- 
tions, is  perfectly  satisfied  as  to  the  fact. 

a  See  Mr.  White's  Treatise  on  the  "  Regeneration  of  Animal  and  Vegetable  Substances," 
(1785)  p.  16. 

*  Dr.  Macartney's  "  Treatise  on  Inflammation,"  p.  7. 
Mr.  Paget  mentions  a  case  of  extirpation  of  a  mammary  tumour,  in  which  the  greater 


REPARATIVE     PROCESS.  345 

surgeon  ought  to  favour  it  as  much  as  possible,  by  procuring  the  most  exact 
coaptation  of  the  wounded  parts,  and  by  repressing  any  tendency  to  inflammation 
which  will  interfere  with  it.  This  is  the  mode  of  union  which  was  spoken-of  by 
John  Hunter  as  'healing  by  the  first  intention/  He  supposed  that  the  union 
takes  place  through  the  medium  of  the  blood  intervening  between  the  lips  of  the 
wound,  which  undergoes  organization  into  a  connecting  tissue  ;  but  it  is  now 
certain  that  although  blood  may  become  organized,  especially  when  effused  into  a 
wound  secluded  from  the  air,  yet  that  its  intervention  opposes,  rather  than 
favours,  healing  by  immediate  union. 

362.  That  which  is  commonly  known  amongst  British  Surgeons  as  '  healing 
by  the  first  intention/  is  that  which  was  designated  by  Hunter  as  '  union  by 
adhesion'  or  by  'adhesive  inflammation.'     This  process  takes-place  in  the  case 
of  incised  wounds,  of  which  the  edges  are  not  brought  into  perfect  coaptation, 
or  in  which  some  inflammatory  action  is  present,  which  gives-rise  to  the  effusion 
of  plastic  lymph.     In  either  case,  the  connection  is  finally  re-established  by  the 
organization  of  the  lymph,  into  which  vessels  pass  from  both  surfaces ;  but  the 
intervention  of  this  bond  is  manifested  in  the  persistence  of  the  cicatrix,  which 
is  quite  distinguishable  by  its  peculiar  appearance  from  the  surrounding  tissue. 
A  very  good  example  of  this  process,  as  it  takes-place  under  favourable  circum- 
stances, is  presented   after  operations  for  hare-lip;  the  wound  left  by  which, 
however,  may  partly  heal  by  '  immediate  union.'     Even  the  moderate  effusion 
of  lymph,  to  a  degree  that  is  altogether  salutary,  cannot  be  regarded  as  alone 
sufficing,  under  such  circumstances,  to  constitute  Inflammation.     But  it  is  well 
known  that  if  a  slight  wound,  which  is  thus  healing,  be  provoked  to  an  increased 
degree  of  inflammation,  its  progress  is  interrupted ;  and  all  the  means  which  the 
Surgeon  employs  to  promote  union,  are  such  as  tend  to  prevent  the  accession  of 
this  state.  —  The  only  case  in  which  the  concurrence  of  Inflammation  can  be 
regarded  as  salutary,  is  that  in  which  there  is  a  deficiency  of  Fibrin  in  the  blood, 
causing  a  deficient  organizability  of  the  lymph.     It  has  been  seen  that  the 
amount  of  fibrin  is  rapidly  increased  by  inflammation  (§  188)  :  and  the  Surgeon 
well  knows  that  a  wound  with  pale  flabby  edges,  in  a  depressed  state  of  the  sys- 
tem, will  not  heal,  until  some   degree  of  Inflammation   has  commenced.     But 
when  the  inflammatory  state  has  developed  itself,  in  however  trifling  a  degree, 
there  is  always  a  risk  of  its  proceeding  further,  and  occasioning  a  degeneration 
of  the  plastic  material,  so  that  the  formation  of  pus-cells  and  the  effusion  of 
purulent  fluid  take  place,  instead  of  the  development  of  uniting  tissues. 

363.  The  reparation  of  wounds,  in  which  there  has  been  so  great  a  loss  of 
substance  that  neither  immediate  union  nor  adhesion  by  a  thin  layer  of  coagu- 
lable  lymph  can  take  place,  is  accomplished  by  the  gradual  development  of  new 
tissue  from  the  l  nucleated  blastema '  with  which  the  cavity  is  first  filled.     But 
this  may  take  place  in  different  modes,  according  to  the   degree  in  which  it  i? 
disturbed  by  the  Inflammatory  process;  and  it  should  be  the  great  object  of  the 
Surgeon,  to  procure  the  most  favourable  method  of  its  performance.     It  has  been 
shown  by  Mr.  Paget  (Op.  cit.),  that  the  mode  in  which  the  process  of  filling-up 
is  accomplished,  differs  essentially  according  as  the  wound  is  subcutaneous,  or  is 
exposed  to  air.     In  the  former  case,  the  nucleated  blastema  is  gradually  developed 
into  fibrous  tissues  without  any  loss,  and  usually  with  freedom  from  local  inflam- 
mation (beyond  what  may  have  been  requisite  for  the  production  of  the  plastic 
fluid),  as  well  as  from  constitutional  irritation.     In  the  latter  case,  the  nucleated 
blastema  is  developed  into  cells ;  and  those  on  its  exposed  surface  are  unable, 
either  from  degeneration  or  from  imperfect  development,  to  pass-on  to  any  higher 
form  of  organization,  but  take-on  the  characters  of  pus-cells,  and  are  only  fit  to 

part  of  the  wound  was  found  to  have  healed  after  this  fashion  ;  the  skin  and  fascia  having 
eo  firmly  adhered,  that  no  indication  existed  of  their  previous  detachment ;  and  no  effusion 
of  coagulable  lymph,  or  production  of  a  connecting  tissue,  being  detectable  by  microscopic 
examination.  (•«  Lectures  on  Surgical  Pathology,"  p.  132,  Am.  Ed  ) 


346  OF    NUTRITION. 

be  cast-off.  Hence  there  is  a  continual  loss  of  plastic  material,  the  amount  of 
which,  in  the  case  of  an  extensive  suppurating  sore,  forms  a  most  serious  drain 
upon  the  system;  whilst,  at  the  same  time,  the  local  inflammation  gives-rise  to 
more  or  less  of  constitutional  disturbance,  and  the  formation  of  new  tissue  is  by 
no  means  so  perfect  as  in  the  preceding  case.  In  cold-blooded  animals,  however, 
the  contact  of  air  does  not  produce  this  disturbance;  and  we  see  wounds  with 
extensive  loss  of  substance  gradually  n'lled-up  in  them  by  the  development  of 
new  tissue,  without  any  suppuration  or  other  waste  of  material,  very  much  as  in 
subcutaneous  wounds  of  warm-blooded  animals.  This  method  of  healing,  which 
has  been  termed  by  Dr.  Macartney  the  '  modelling  proeej-s/  is  nothing  else  than 
healing  by  granulations  under  the  most  favourable  circumstances;  and  to  procure 
this  should  be  the  endeavour  of  the  Surgeon,  who  too  frequently  considers  sup- 
purative  granulation  as  the  only  means  by  which  an  open  wound  can  be  filled-up. 
The  difference  between  the  two  modes  of  reparation  is  often  one  of  life  and  death, 
especially  in  the  case  of  large  burns  on  the  trunk  in  children;  for  it  frequently 
happens  that  the  patient  sinks  under  the  great  constitutional  disturbance  occa- 
sioned by  a  large  suppurating  surface,  although  he  has  survived  the  immediate 
shock  of  the  injury. — Now  the  means  adopted  by  Nature  to  bring  this  about,  in 
warm-blooded  animals,  is  the  formation  of  a  scab;  which  reduces  the  wound 
more  nearly  to  the  condition  of  a  subcutaneous  one,  so  that  the  reparative 
growth  and  formation  of  new  tissue  take  place  (under  favourable  circumstances) 
without  any  suppuration,  and  with  scarcely  any  irritation  ;  the  subsequent  cica- 
trix,  too,  being  much  more  like  the  natural  parts,  than  are  any  scars  formed  in 
wounds  that  remain  exposed  to  the  air.  In  the  Human  subject,  however,  the 
process  is  far  less  certain  than  it  is  among  the  lower  animals,  owing  to  the 
liability  to  inflammation  in  the  wounded  part,  and  the  consequent  effusion  of 
fluid,  which  produces  pain,  compresses  the  wounded  surface,  or  forces-off  the 
scab,  with  great  discomfort  to  the  patient,  and  retardation  of  the  healing.  Small 
wounds,  however,  in  persons  of  good  habit  of  body,  and  in  parts  which  can  be 
completely  kept  at  rest,  readily  heal  in  this  manner;  and  large  wounds  have  been 
known  to  close,  in  the  same  desirable  mode,  beneath  a  clot  of  inspissated  blood. 
In  fact,  among  'uncivilized'  nations,  whose  habits  of  life  are  favourable  to  health, 
—  their  bodies  being  continually  exposed  to  fresh  air,  their  food  wholesome  and 
taken  in  moderation,  and  their  drink  water  or  other  unstimulating  liquids,  — 
there  seems  to  be  as  great  a  tendency  to  this  method  of  reparation,  as  exists 
among  the  lower  animals;  and  the  difficulty  of  procuring  it  among  the  members 
of  'civilized'  communities,  is  owing,  without  doubt,  to  the  unnatural  conditions 
under  which  they  too  frequently  live.  Seeing  as  we  continually  do,  the  effects 
of  foul  air,  of  habitual  excess  in  diet,  and  of  the  constant  abuse  of  stimulants, 
in  impairing  that  form  of  the  reparative  process  which  must  be  regarded  as  the 
hast  favourable,  namely,  the  closure  of  a  wound  by  suppurating  granulations,  it 
is  very  easy  to  comprehend,  that,  to  induce  the  most  favourable  method,  the  most 
perfect  freedom  from  all  pernicious  agencies  should  be  required. 

364.  The  most  effectual  means  of  promoting  this  kind  of  Reparative  process, 
and  of  preventing  the  interference  of  Inflammation,  vary  according  to  the  nature 
of  the  injury.  The  exclusion  of  air  from  the  surface,  and  the  regulation  of  the 
temperature,  appear  the  two  points  of  chief  importance.  By  Dr.  Macartney,  the 
constant  application  of  moisture  is  also  iusisted-on.1  He  states  that  the  imme- 
diate effects  of  injuries,  especially  of  such  as  act  severely  upon  the  sentient  ex- 
tremities of  the  nerves,  are  best  abated  by  the  action  of  "  steam  at  a  high  but 
comfortable  temperature,  the  influence  of  which  is  gently  stimulant,  and  at  the 
same  time  extremely  soothing."  After  the  pain  and  sense  of  injury  have  passed 
away,  the  steam,  at  a  lower  temperature,  may  be  continued;  and,  according  to 
Dr.  M.,  no  local  application  can  compete  with  this,  when  the  Inflammation  is  of 
an  acti\^  character.  For  subsequently  restraining  this,  however,  so  as  to  promote 
1  "Treatise  on  Inflammation,"  p.  178. 


REPARATIVE     PROCESS.  847 

the  simple  reparative  process,  "Water-dressing  will,  lie  considers,  answer  suffi- 
ciently well  ;  its  principal  object  being  the  constant  production  of  a  moderate 
degree  of  Cold,  which  diminishes,  whilst  it  does  not  extinguish,  sensibility  and 
vascular  action,  and  allows  the  Reparative  process  to  be  carried-on  as  in  the  infe- 
rior tribes  of  animals.  The  reduction  of  the  heat  in  an  extreme  degree,  as  by 
the  application  of  ice  or  iced  water,  is  not  here  called-for,  and  would  be  positively 
injurious ;  since  it  not  only  renders  the  existence  of  inflammation  in  the  part  im- 
possible, but,  being  a  direct  sedative  to  all  vital  activity,  suspends  also  the  pro- 
cess of  restoration.  The  efficacy  of  Water-dressing  in  injuries  of  the  severest 
character,  and  in  those  which  are  most  likely  to  be  attended  with  violent  Inflam- 
mation (especially  wounds  of  the  large  joints)  has  now  been  established  beyond 
all  question;  and  its  employment  is  continually  becoming  more  general.1 — Other 
plans  have  been  proposed,  however,  which  seem  in  particular  cases  to  be  equally 
effectual.  To  Dr.  Greenhow,  of  Newcastle,  for  instance,  it  was  accidentally  sug- 
gested, a  few  years  since,2  to  cover  the  surface  of  recent  burns  with  a  liquefied 
resinous  ointment,  so  as  to  form  an  artificial  scab;  and  he  states  that  in  this 
manner  suppuration  may  be  prevented,  even  where  large  sloughs  are  formed ;  the 
hollow  being  gradually  filled-up  by  new  tissue,  which  is  so  like  that  which  has 
been  destroyed,  that  no  change  in  the  surface  manifests  itself,  and  none  of  that 
contraction,  which  ordinarily  occurs  even  under  the  best  management,  subse- 
quently takes  place.  — A  plan  has,  moreover,  been  proposed  for  preventing  sup- 
puration and  promoting  reparation  by  the  'modelling'  process,  which  consists  in 
the  application  of  warm  dry  air  to  the  wounded  surface.  Although  the  experi- 
ments yet  published  have  not  been  entirely  satisfactory,  they  seem  to  show  that, 
whilst  the  process  of  healing  may  be  slower  under  treatment  of  this  kind,  it  is 
attended  with  less  constitutional  disturbance  that  is  often  unavoidable  in  the 
ordinary  method;  and,  that  it  may,  therefore,  be  advantageously  put  in  practice 
in  those  cases,  in  which  the  condition  of  the  patient  requires  every  precaution 
against  such  an  additional  burthen, — as  after  amputation  in  a  strumous  subject.3 
365.  When  the  process  of  healing  of  an  open  wound  by  Suppurative  Granu- 
lation is  attentively  watched,  it  is  seen  that  the  first  stage  is  the  formation  of  a 
'  glazing '  on  the  exposed  surface,  which  closely  resembles  the  buffy  coat  of  the 
blood,  being  composed  of  coagulated  fibrin  and  colourless  corpuscles;  in  this 
manner  a  sort  of  imperfect  epithelium  may  be  formed,  within  half  an  hour  after 
the  surface  has  been  laid-bare.  The  increase  of  this  glazing  is  the  prelude  to 
the  formation  of  granulations;  but  whilst  it  is  going-on,  there  is,  in  and  about 
the  wound,  an  appearance  of  complete  inaction,  a  sort  of  calm,  in  which  scarcely 
anything  appears  except  a  slight  oozing  of  serous  fluids  from  the  wound,  and 
which  continues  from  one  day  to  eight,  ten,  or  more,  according  to  the  nature  and 
extent  of  the  wounded  part,  and  the  general  condition  of  the  body.  "  This 
calm,"  says  Mr.  Paget,  "  may  be  the  brooding-time  for  either  good  or  evil ;  whilst 
it  lasts,  the  mode  of  union  of  the  wound  will,  in  many  cases,  be  determined  ; 
the  healing  may  be  perfected,  or  a  slow  uncertain  process  of  repair  may  be  but 
just  begun ;  and  the  mutual  influence  which  the  injury  and  the  patient's  consti- 
tution are  to  exercise  on  one  another,  appears  to  be  manifested  more  often  at  or 
near  the  end  of  this  period,  than  at  any  other  time."  The  cessation  of  this 
period  of  calm,  and  the  active  commencement  of  the  reparative  operations,  are 
marked  by  the  restoration  of  the  flow  of  blood  in  the  vessels  of  the  wounded 
part;  but  the  current  is  not  altogether  normal,  being  slower  but  fuller  than  natu- 
ral, so  that  on  the  whole  more  blood  than  usual  passes  through  the  capillary 
plexus.  This  increased  afflux  of  blood  is  followed  by  effusion  of  plastic  material 
in  increased  proportion ;  and  it  is  from  this  effusion,  that  the  granulating  process 
properly  commences.  —  The  plastic  material  effused  upon  the  surface  of  an  open 

1  See  an  account  of  the  results  of  this  treatment  by  Dr.  Gilchrist,  in  "Brit,  and  For 
Med.  Rev.,"  July,  1846,  p.  242. 
a  "  Medical  Gazette,"  Oct.  13,  1838. 
1  See  M.  Jules  Guyot  "De  1'emploi  de  la  Chaleur  dans  le  Traitement  des  Ulceres.  &c. 


348  OF   NUTRITION. 

wound,  is  first  developed  into  cells ;  and  these  cells,  in  the  deeper  portions  of  the 
effusion,  are  metamorphosed  into  fibrinous  tissue,  of  which  the  substance  of  the 
granulations  are  composed.  Those  which  are  formed  upon  the  surface,  however, 
are  converted  into  pus-cells  (§  375)  ;  in  some  instances  (as  Mr.  Paget  has  pointed- 
out)  by  degeneration  from  a  higher  development;  in  other  cases  by  an  originally 
imperfect  development :  and  thus  the  granulation-surface  is  constantly  in  a  state 
of  morbid  action,  and  a  large  proportion  of  the  plastic  material  is  completely 
wasted.  The  layer  of  pus,  however,  serves  as  a  sort  of  epithelium  for  the  sub- 
jacent granulation-tissue,  in  which  we  find  not  only  a  complete  formation  of  cells, 
but  a  commencement  of  the  metamorphosis  of  these  cells  into  fibres,  before 
blood-vessels  make  their  appearance  in  the  tissue.  These  blood-vessels  are  formed 
by  "  out-growth  "  from  the  subjacent  capillaries,  in  the  mode  elsewhere  described 
(PniNC.  OF  GEN.  PHYS.,  Am.  Ed.).  From  the  investigations  of  Mr.  Listen,  it 
appears  that  the  vessels  of  the  subjacent  tissue  are  much  enlarged,  and  assume  a 
varicose  character.  The  bright  red  colour  of  the  granulations,  however,  does  not 
depend  on  their  vascularity  alone ;  for  the  cells  themselves,  especially  those  most 
recently  evolved,  are  of  nearly  as  deep  a  colour  as  the  blood-corpuscles ;  and  the 
sanguineous  exudation  which  follows  even  the  slightest  touch  of  the  granulating 
surface,  does  not  proceed  from  blood  effused  from  the  newly-formed  vessels  only ; 
for  the  red  fluid  shed  in  this  manner  contains,  besides  blood-discs,  newly- 
developed  red  cells,  ruddy  cytoblasts,  pale  granules,  and  reddish  serum.  It  is  a 
common  property  of  animal  cytoblasts,  that  they  present  a  reddish  colour  on  their 
first  formation,  when  in  contact  with  oxygen;  but  this  hue  they  lose  again, 
whether  they  advance  to  perfect  development  and  become  integral  parts  of  a 
living  tissue,  or  die  and  degenerate. 

866.  The  process  of  Suppurative  Granulation,  then,  appears  to  differ  from  the 
process  of  granulation  as  it  takes  place  in  closed  wounds,  or  in  a  warm,  moist  at- 
mosphere (the  i  modelling-process  '  of  Dr.  Macartney),  essentially  in  this  : — that 
a  large  part  of  the  exudation-corpuscles  deposited  on  the  wounded  surface  dege- 
nerate into  pus  in  the  former  case,  whilst  none  are  thus  wasted  in  the  latter ;  — 
but  that  the  existence  of  inflammation  occasions  a  more  copious  supply  of  fibrin 
in  the  former  case,  and  increases  its  tendency  to  become  organized  :  the  filling-up 
of  a  wound  with  granulations  being  thus  a  much  more  rapid  process,  than  that 
renewal  of  the  completely-formed  tissues,  which  may  take  place  in  the  absence 
of  inflammation.     The  imperfect  character  of  the  granulation-structure  is  shown, 
by  the  almost  complete  disappearance  of  it  after  the  wound  has  closed-over. 
The  proportion  of  it  in  immediate  contact  with  the  subjacent  tissue,  however, 
appears  to  undergo  a  higher  organization ;  for  it  becomes  the  medium  by  which 
the  cicatrix  is  made  to  adhere  to  the  bottom  of  the  wound.     It  is  very  liable  to 
undergo  changes  which  end  in  its  disintegration ;  as  is  evident  from  the  known 
tendency  to  re-opening,  in  wounds  that  have  been  closed  in  this  manner. 

867.  When  two  opposite  surfaces  of  granulations,  well  developed,  but  not  yet 
covered  with  cuticle,  are  brought  into  apposition,  they  have  a  tendency  to  unite, 
like  the  two  oiiginal  surfaces  of  an  incised  wound.     This  method  of  union,  which 
was  noticed  by  John  Hunter,  has  been  appropriately  termed  '  secondary  adhe- 
sion' by  Mr.  Paget.     The  surgeon  may  frequently  have  recourse  to  it  with  great 
advantage,  when  primary  adhesion  is  impossible,  and  when  the  filling-up  of  the 
wound  with  granulations  would  be  a  tedious  process,  and  very  exhausting  to  the 
patient.     In  applying  it  to  practice,  it  is  essential  to  success,  first,  that  the  gra- 
nulations should  be  healthy,  not  inflamed  or  profusely  secreting,  nor  degenerated 
as  those  in  sinuses  commonly  are;  and  secondly,  that  the  contact  between  them 
should  be  gentle  but  maintained :  it  seems  desirable,  also,  that  the  granulation- 
surfaces  should  be  as  much  as  possible  of  equal    development,  and  alike  in 
character  ' 

1  On  the  whole  subject  of  the  Reparative  Processes,  see  Mr.  Paget's  admirable  "  Lec- 
tures on  Surgical  Pathology"  (Lect.  vii. — xii.,  Am.  Ed.) ;  from  which  many  of  the  foregoing 
statements  and  doctrines  are  adopted. 


ABNORMAL   FORMS    OF   THE   NUTRITIVE   PROCESS.  340 

3. — Abnormal  Forms  of  the  Nutritive  Process 

868.  Under  the  preceding  bead,  we  have  considered  the  chief  variations  in 
the  degree  of  activity  that  are  witnessed  in  the  ordinary  or  normal  conditions  of 
the  Nutritive  process,  —  those  conditions,  namely,  in  which  the  products  are 
adapted,  by  their  similarity  of  character,  to  replace  those  which  have  been  re- 
moved by  disintegration.  But  we  have  now  to  consider  those  forms  of  this  pro- 
cess,—  in  which  the  products  are  abnormal, — being  different  from  the  tissues 
they  ought  to  replace.  We  shall  confine  ourselves  to  a  brief  examination  of  a 
few  of  some  of  the  most  important  of  these  states;  and  that  which  first  claims 
our  consideration,  on  account  of  the  frequency  of  its  occurrence  and  the  import- 
ance of  its  results,  is  Inflammation.  —  Although  Pathologists  have  been  ac- 
customed to  look  for  the  *  proximate  cause'  of  the  phenomena  which  essentially 
constitute  the  Inflammatory  state,  or,  in  other  words,  for  the  first  departure  from 
the  normal  course  of  vital  action,  in  the  enlarged  or  contracted  dimensions  of 
the  blood-vessels  of  the  inflamed  part,  or  in  the  altered  rate  of  movement  of 
the  blood  through  it,  yet  it  may  now  be  safely  affirmed  that  these  are  only 
secondary  alterations,  depending  upon  an  original  and  essential  perversion  of  that 
normal  reaction  between  the  blood  and  the  tissues,  which  constitutes  the  proper 
Nutritive  process.  This  perversion  manifests  itself  (1)  in  a  diminution  in  the 
formative  activity  of  the  tissues,  leading  to  their  degeneration  and  death ;  (2)  in 
a  tendency  to  augmented  production  of  the  plastic  components  of  the  blood ;  and 
(3)  in  the  effusion  of  these  components,  either  in  a  state  in  which  they  may  pass 
into  a  low  form  of  organized  tissue,  or  in  such  a  degraded  condition  that  they 
are  altogether  unorganizable,  and  are  fit  only  to  be  cast-out  from  the  body.  Each 
of  these  phenomena  requires  a  separate  examination,  both  as  to  its  causes  and  its 
consequences. 

369.  Although  it  has  been  customary  to  speak  of  Inflammation  as  a  state  of 
'increased  action'  in  the  part  affected, — of  which  increased  action,  the  augmen- 
tation in  the  bulk  and  weight  of  an  inflamed  part,  and  in  the  quantity  of  blood 
which  passes  through  it,  together  with  its  higher  temperature  and  more  acute 
sensibility,  would  seem  to  furnish  sufficient  evidence,  —  yet  all  these  signs  are 
found  to  be  deceptive,  when  they  are  more  closely  examined ;  and  the  conclusion 
is  forced  upon  us,  that  the  vital  power  of  the  part  is  really  depressed  rather  than 
exalted.     For  the  increase  in  bulk  and  weight  is  not  due  to  such  an  augmentation 
of  its  proper  tissue,  as  would  truly  constitute   Hypertrophy;  on  the  contrary, 
even  in  the  slightest  forms  of  Inflammation  there  is  such  a  diminution  in  the 
rate  of  its  nutrition,  as  really  constitutes  Atrophy;  and  such  augmentation  of 
the  solid  mass  as  may  take  place,  is  produced  by  the  passage  of  the  effused  fluid 
into  an  organized  tissue  of  the  lowest  kind,  and  this  in  virtue  rather  of  its  own 
plasticity,  than  of  the  vital  force  which  it  derives  from  the  tissues  which  it  infil- 
trates.    That  there  has  been  an  atrophy  rather  than  a  hypertrophy  of  the  proper 
fabric  of  the  part,  becomes  evident  enough  when  the  inflammation  has  passed- 
away,  and  this  newly-formed  tissue  undergoes  degeneration  and  absorption.     The 
only  tissues  in  which  there  is  any  appearance  of  increased  formation  during  the 
inflammatory  state,  are  those  which  correspond  in  their  low  type  of  organization 
with  the  new  tissue  thus  generated  :  namely,  the  areolar  and  other  simple  fibrous 
tissues,  and  also  the  osseous,  of  which  the  organized  basis  is  somewhat  of  the 
same  kind.     When  the  Inflammation  is  more  severe,  the  tendency  to  degenera- 
tion in  the  proper  tissues  of  the  part  becomes  very  obvious :  for  it  is  by  their 
interstitial  decay  and  removal,  that  the  cavity  of  an  abscess  is  formed ;  it  is  by 
their  superficial  death  and  absorption  or  solution,  that  ulceration  takes  place; 
and  it  is  in  the  death  of  a  whole  mass  at  once,  that  gangrene  consists. 

370.  That  a  diminution  in  the  formative  capacity  of  the  Tissues  is  an  essential 
characteristic  of  the  Inflammatory  state,  further  appears  from  the  study  of  its 
Etiology;  for  whether  the  causes  to  which  the  inflammatory  attack  may  be  traced 


350  OF    NUTRITION. 

are  local  or  general,  acting  primarily  upon  the  tissues  of  the  part,  or  first  affect- 
ing  the  blood,  their  operation  is  essentially  the  same.  Thus  the  local  causes  are 
all  obviously  such,  as  tend  either  directly  to  depress  the  vital  powers,  or  to  elevate 
them  at  first,  and  then  depress  them  by  exhaustion.  Of  the  former  kind  are 
cold  and  mechanical  injury ;  also  many  chemical  agents,  whose  operation  tends 
to  bring  back  the  living  tissues  to  the  condition  of  inorganic  compounds.  Under 
the  latter  category  are  to  be  ranked  all  those  agencies,  which  produce  over-exer- 
tion of  the  functional  power  of  the  part ;  amongst  which  may  be  named  heat, 
when  not  so  excessive  as  to  produce  a  directly  destructive  effect.  Now  cold, 
heat,  chemical  agents,  and  mechanical  injury,  when  operating  in  sufficient  inten- 
sity, at  once  kill  the  part,  by  entirely  destroying,  instead  of  merely  depressing, 
its  vital  powers  ;  and  it  is  on  the  borders  of  the  dead  part,  where  the  cause  has 
acted  with  less  potency,  that  we  find  the  inflammatory  state  subsequently  pre- 
senting itself.  —  On  the  other  hand,  there  can  be  no  doubt  that  many  inflamma- 
tions have  their  origin  in  the  morbid  conditions  of  the  Blood,  which,  without  any 
other  cause  whatever,  may  determine  all  the  other  phenomena.  This  is  most 
obvious  with  regard  to  those  of  a  l specific'  kind;  but  it  is  also  probably  true  of 
the  majority  of  the  so-called  spontaneous  or  constitutional,  as  distinguished  from 
traumatic  inflammations.  We  seem,  indeed,  to  be  able  to  trace  a  regular  grada- 
tion, between  inflammatory  attacks  which  are  entirely  traceable  to  the  introduc- 
tion of  a  poison  into  the  blood,  and  those  which  result  from  causes  purely  local. 
Under  the  first  head,  we  may  unquestionably  rank  such  inflammatory  diseases  as 
are  productive  by  inoculation,  the  eruptive  fevers  for  example ;  and  scarcely  less 
thoroughly  demonstrated  are  the  cases  of  rheumatism  and  gout,  and  many  in- 
flammations of  the  cutaneous  textures,  which,  when  occurring  in  the  chronic 
form,  tend  to  exhibit  a  regular  symmetry  (§  217).  In  all  such  cases,  the  local 
affections  are  the  external  signs  of  the  general  affection  of  the  blood,  just  as  are 
the  inflammations  produced  by  the  introduction  of  arsenic  or  of  other  irritant 
poisons  into  the  circulation ;  and  they  may  in  fact  be  reasonably  attributed  to  the 
impairment  of  the  formative  activity  of  the  parts  upon  which  these  poisons  fix; 
themselves,  in  virtue  of  their  '  elective  affinity '  (§  223),  just  as  the  peculiar 
functional  activity  of  the  nervous  centres  is  affected  by  narcotic  poisons.  And 
this  view  of  the  really-local  action  of  what  are  primarily  regarded  as  general  or 
constitutional  causes  of  inflammation,  is  confirmed  by  the  fact,  that  the  localiza- 
tion of  the  perverted  nutritive  condition  is  often  determined  (as  both  Dr.  W. 
Budd  and  Mr.  Paget  have  remarked)  by  a  previous  or  concurrent  weakening  or 
depression  of  the  vital  activity  of  the  part.  Thus  a  part  which  has  been  the 
seat  of  former  disease  or  injury,  and  which  has  never  recovered  its  vigour  of 
nutrition,  is  always  more  liable  than  another  to  be  the  seat  of  local  manifestation 
of  blood-disease;  it  is,  in  common  language,  the  'weak  part/1  And  it  fre- 
quently needs  such  a  concurrent  operation  of  a  local  depressing  cause,  to  fix  and 
develope  the  action  of  the  constitutional  cause,  or  blood-disorder;  thus,  a  rheu- 
matic or  gouty  diathesis  may  exist  for  some  time  (as  when,  to  use  a  common  ex- 
pression, the  disease  is  ' flying  about'  the  patient),  and  yet  the  poison  may  not 
have  sufficient  potency  to  produce  an  attack  of  acute  inflammation,  until  the 
vitality  of  some  particular  organ  becomes  depressed  by  cold,  over-exertion,  or 
some  similar  influence,  which  would  not  have  itself  engendered  the  diseased 
action,  had  it  not  been  for  the  concurrence  of  the  morbid  condition  of  the  blood. 
—  Thus  we  seem  justified  in  concluding,  that,  whether  the  causes  of  Inflamma- 
tion act  directly  upon  the  tissues  of  a  part,  or  whether  they  act  upon  it  through 

1  Thus  Impetigo  appears  about  blows  and  scratches  in  unhealthy  children,  and  Erysi- 
pelas first  attacks  the  seat  of  local  injury  in  men  with  unhealthy  blood.  Perhaps  as  good 
an  example  as  any,  is  afforded  by  the  uniform  limitation  of  the  inflammation  con?equent 
upon  the  introduction  of  Vaccine  matter  into  the  blood,  to  the  spots  in  which  the  puncture 
was  made ;  notwithstanding  that  the  whole  mass  of  blood  is  affected  by  it,  as  is  shown  by 
its. incapacity  for  subsequently  developing  the  poison  of  small-pox. — See  also  %  231 


ABNORMAL   FORMS    OF   THE    NUTRITIVE    PROCESS. — INFLAMMATION.      3f?l 

the  intermediation  of  the  blood,  their  effect  is  to  produce  a  depression  in  its  vital 
powers,  which  manifests  itself  in  a  deficient  formative  activity,  and  in  an  in- 
creased tendency  to  degeneration  ;  and  that  this  is  one  of  the  primary  and  essen- 
tial conditions  of  Inflammation. 

371.  This  view  is  by  no  means  inconsistent  with  the  occurrence  of  other  mani- 
festations of  Inflammation,  which  have  been  supposed  to  indicate  'increased 
action;'  and,  in  fact,  it  is  in  such  striking  accordance  with  the  phenomena  pre- 
sented by  the  movement  of  the  blood,  when  these  are  interpreted  by  the  princi- 
ples already  laid-down,  as  to  afford  a  powerful  confirmation  to  both  doctrines. 
The  usual  condition  of  the  vessels  of  an  inflamed  part,  is  one  of  dilatation ;  and 
this  may  be  fairly  attributed  to  the  lowered  vitality  of  their  walls,  whereby  they 
yield  too  readily  to  the  distending  force  of  the  current  of  blood.  But  this  cur- 
rent moves  too  slowly ;  and  its  retardation  may  gradually  increase,  in  the  part 
most  intensely  inflamed,  to  the  point  of  complete  stagnation.  Now  this  altered 
rate  of  movement  cannot  be  attributed  to  any  general  cause  :  nor  can  it  be  ac- 
counted-for  by  the  change  in  the  diameter  of  the  vessels;  for,  on  the  one  hand, 
it  may  occur  with  a  constricted  state  of  the  vessels,  whilst,  on  the  other,  in  the 
vessel's  surrounding  the  inflamed  part,  which  partake  of  the  dilated  condition, 
the  flow  of  blood  is  so  far  from  being  retarded,  that  it  usually  takes-place  more 
rapidly  than  usual.  But  it  may  be  fairly  considered  as  the  result  of  the  lowered 
or  suspended  nutritive  activity  of  the  part,  which  will  tend  to  retard  or  entirely 
check  the  motion  of  blood  in  the  systemic  capillaries,  just  as  the  want  of  aeration 
retards  or  checks  the  pulmonary  circulation  (§272)..  It  is  quite  true  that  a 
larger  amount  of  blood  passes  through  a  limb,  of  which  some  part  is  in  a  state 
of  active  inflammation,  than  passes  through  the  corresponding  sound  limb;  but 
this  is  far  from  indicating  '  increased  action'  in  the  inflamed  part,  being  dependent 
upon  the  augmented  flow  of  blood  through  the  tissues  which  surround  it;  and 
if  the  whole  of  a  limb  be  in  a  state  of  inflammation  passing-on  to  gangrene  (as 
occurs  when  a  {  frost-bitten'  limb  has  been  incautiously  warmed),  the  amount  of 
blood  which  passes  through  it  is  diminished.  —  It  would  be  just  as  erroneous  to 
assume  the  elevated  temperature  of  an  inflamed  part  as  a  sign  of  'increased 
action'  in  it;  for  this  elevation  is  no  doubt  attributable  in  part  to  the  augmented 
flow  of  blood  through  the  surrounding  vessels ;  and,  so  far  as  it  depends  upon 
local  changes,  it  obviously  indicates  a  more  rapid  disintegration  of  tissue,  rather 
than  a  more  energetic  production  of  it;  since  it  is  in  the  former  state,  rather 
than  in  the  latter,  that  the  conditions  of  the  development  of  heat  (on  the  che- 
mical theory)  are  supplied,  as  we  see  that  the  heat  of  a  muscle  is  the  greatest 
when  it  is  being  disintegrated  by  active  exercise,  not  when  it  is  being  repaired 
by  the  formation  of  new  tissue  in  the  intervals  of  repose.  But,  as  Mr.  Paget 
justly  remarks,  "  this  phenomenon  is  involved  in  the  same  difficulty  as  are  all 
those  that  concern  the  local  variations  of  temperature  in  the  body ;  difficulties 
which  the  doctrines  of  Liebig,  however  good  for  the  general  production  of  heat, 
are  quite  unable  to  explain."  (See  Chap,  x.)  —  And  lastly,  with  regard  to  the 
unusual  tenderness  of  inflamed  parts,  this  is  obviously  due  to  such  a  combination 
of  causes,  neither  of  which  can  be  legitimately  held  to  indicate  an  increase  of  its 
proper  vital  activity,  that  nothing  can  be  rested  on  this  alone ;  especially  as  we 
see  an  augmentation  in  the  susceptibility  of  the  sentient  nerves,  under  many 
circumstances  (as  in  hysterical  disorders),  in  which,  far  from  an  augmented,  there 
is  obviously  a  diminished  activity  in  the  parts  from  which  they  spring.  —  That 
neither  an  alteration  in  the  circulation  of  a  part,  nor  a  departure  from  the  normal 
condition  of  its  nervous  supply,  can  be  regarded  as  one  ol  the  essential  pheno- 
mena of  inflammation,  is  obvious  from  this,  that  the  most  important  phenomena 
of  inflammation  may  present  themselves,  as  results  of  injury  or  disease,  in  parts 
that  have  neither  blood-vessels  nor  nerves  :  this  is  seen  in  the  deposition  of  lymph 
in  the  cornea,  in  the  ulceration  of  the  cornea  and  of  articular  cartilages,  and  in 
3ther  morbid  actions  in  these  parts,  which,  if  ever  they  are  vascular,  become  so 


352  OF    NUTRITION. 

only  after  the  effusion  of  lymph  in  them,  the  new  vessels  being  formed  in  this 
lymph,  and  not  in  the  tissues  themselves.  Here  it  is  obvigus  that  the  whole 
change  consists  in  a  perversion  of  the  nutritive  actions  which  the  tissues  ought 
to  carry-on,  at  the  expense  of  the  materials  which  they  draw  from  the  blood  of 
the  surrounding  vessels. 

372.  Of  the  alterations  in  the  condition  of  the  Blood  in  Inflammation,  an 
account  has  already  been  given  (§§  187 — 191);  and  it  is  here  only  necessary  to 
recapitulate  them.     The  most  characteristic  is  the  augmentation,  either  of  the 
organizable  or  plastic  fibrin,  or  of  the  organized  colourless  corpuscles ;  the  in- 
creased production  of  these  two  components  seeming  to  bear  in  some  degree  a 
-relation  of  reciprocity,  the  one  to  the  other.    The  increase  of  Fibrin  may  be  con- 
sidered as  the  alteration  most  characteristic  of  £  previously-healthy  and  vigorous 
state  of  the  system;  and  it  is  in  the  inflammations  which  occur  in  such  subjects, 
that  the  effusions  are  most  strongly  disposed  to  become  organized,  arid  show  the 
least  tendency  to  undergo  degenerative  changes.    On  the  other  hand,  the  increase 
of  the  Corpuscular  element  seems  to  occur  in  cachectic  or  otherwise  unhealthy 
individuals ;  and  the  inflammatory  effusions  which  partake  of  the  same  character, 
are  far  less  plastic  originally,  and  are  extremely  prone  to  undergo  degeneration, 
either  at  the  time  of  their  effusion,  or  subsequently.     With  this  increase  in  the 
proportion  of  fibrin  and  colourless  corpuscles,  separately  or  in  combination,  there 
is  a  diminution  in  the  proportion  of  the  red  corpuscles,  albumen,  and  salts  of  the 
blood.     None  of  these  changes,  however,  can  be  legitimately  regarded  a-s  origin- 
ally or  essentially  characteristic  of  the  inflammatory  condition ;  they  are,  in  fact, 
to  be  looked-on  rather  as  the  results  of  its  establishment,  constituting  that  series 
of  alterations  in  the  circulating  fluid,  which  is  of  parallel  order  to  that  which 
occurs  in  the  solid  tissues  wherein  the  inflammatory  action  has  been  set-up. 

373.  The  Inflammatory  state  is  further  characterized  by  the  effusion  of  certain 
of  the  components  of  the  Blood,  upon  the  surface,  or  into  the  substance,  of  the 
inflamed  tissues. — The  effusion  of  pure  serum  cannot  be  regarded  as  characteristic 
of  inflammation  ;  since  it  may  take-place  as  a  mere  result  of  congestion,  especially 
when  this  congestion  is  due  to  an  obstruction  to  the  return  of  the  blood ;  whilst, 
again,  it  may  be  due  to  an  altered  condition  of  the  albuminous  constituent  of  the 
blood,  which  favours  its  transudation  (§  183).     The  so-called  serous  effusions 
which  are  poured-forth  in  inflammation,  do  in  reality  contain  fibrin  in  solution  ; 
but  this  fibrin  may  not  manifest  its  presence  by  spontaneous  coagulation,  until 
its  passage  into  the  solid  state  is  favoured  by  the  introduction  of  a  piece  of  the 
washed  clot  of  blood,  or  of  the  buffy  coat,  or  of  muscle  or  some  other  animal 
tissue,  which  seems  to  act  as  a  sort  of  nucleus  of  fibrillation.     The  presence  even 
of  fibrin  in  such  an  effusion,  however,  is  not  in  itself  a  sufficient  proof  of  the 
existence  of  inflammation;  for  it  has  been  shown  by  the  experiments  of  Mr. 
Robinson,1  that  when  the  obstruction  to  the  return  of  blood  by  the  veins  is  so 
great  as  to  occasion  an  excessive  pressure  within  the  capillaries,  the  fluid  which 
transudes  may  contain  enough  fibrin  to  render  it  spontaneously  coagulable. — The 
form  of  exudation  which  is  most  characteristic  of  Inflammation,  is  that  which  is 
known  as  coagulable  lymph  ;  it  is  much  to  be  desired,  however,  that  some  other 
designation  should  be  applied  to  it,  since  the  term  'lymph'  can  only  be  appro- 
priately employed  for  the  fluid  contents  of  the  lymphatic  vessels.     The  peculiar 
characteristic  of  this  inflammatory  exudation,  is  its  capability  of  spontaneously 
passing  into  the  condition  of  an  organized  tissue,  either  fibrous  or  cellular,  or  a 
mixture  of  both;  and  of  thus  forming  'false  membranes'  on  inflamed  surfaces, 
or  solidifying  the  inflamed  part  by  the  interstitial  production  of  similar  lowly- 
organized  textures.     Although  it  has  been  too  much  the  habit  of  Pathologists, 
to  speak  of  '  coagulable '  or  *  plastic  lymph '  as  if  it  were  always  one  and  the 
«ame  thing,  yet  it  really  presents  various  gradations   of  character,  which  are 

1  Medico-Chirurgical  Transactions,"  TO!,  xxvi.,  p.  51. 


ABNORMAL   FORMS    OF   THE   NUTRITIVE    PROCESS. — INFLAMMATION.     353 


[FiG.  89. 


[FiG.  90. 


manifested  in  its  different  degrees  of  organizability,  and  in  the  diverse  nature  of 
the  tissues  developed  from  it;  and,  as  Mr.  Paget  has  pointed  out,'  there  are  two 
typical  forms,  the  fibrinoun,  and  the  corpuscular,  between  which  the  others  are 
intermediate.  The  former  coagulates  into  a  fibrous  clot,  resembling  that  of 
healthy  blood,  but  usually  showing  a 
more  distinct  fibrillation.  (Fig.  89.)  The 
latter  (the  'croupous'  exudation  of 
Eokitansky)  is  characterized  by  the 
want  of  any  proper  coagulation,  the 
fibrous  clot  being  replaced  by  an  aggre- 
gation of  cells,  which  in  their  first  ap- 
pearance resemble  very  nearly  the  pri- 
mordial condition  of  the  corpuscles  of 
the  fluids  of  the  absorbent  vessels,  and 
the  colourless  corpuscles  of  the  blood. 
(Fig.  90.)  It  is  seldom,  however,  that 

either  of  these  typical  forms  of  lymph  K  red  an 

presents  itself  in  a  state  of  complete  iso-   whhe  corpugcles  (three  of  the  latter  arc  figured 
lation  from  the  other;  they  are  much  separately),  and  a  few  fibrinous  fibrils.] 
more  commonly  blended  in  various  pro- 
portions, so  that  one  or  the  other  predominates;    and  it  is  mainly  upon   the 
preponderance  of  fibrin,  that  the  'plasticity'  of  the  exudation  (or  its  capacity 
for    organization)    depends;  whilst  according    to  the  prepon- 
derance  of  corpuscles,  will  be  its  tendency  to  degeneration. 
Thus  the  exudation  of  fibrinous  lymph  is  the  symbol  of  the 
'adhesive'  inflammation;  whilst  that  of  the  'corpuscular'  is 
similarly  characteristic  of  the  '  suppurative '  inflammation. 

374.  It  is  obviously  of  great  consequence  to  ascertain  the 
conditions  which  determine  the  production  of  one  or  other  of 
these  states;  and  these,  as  Mr.  Paget  has  remarked  (loc.  cit.), 
may  be  considered  under  three  heads, — (1)  the  previous  state 
of  the  blood,  (2)  the  seat  of  the  inflammation,  and  (3)  the 
degree  and  character  of  the  inflammation.  The  condition  of 
tJte  Hood,  as  determining  that  of  the  lymph,  has  been  carefully 
studied  by  Rokitansky ;  who  has  shown  that  the  characters  of 
inflammatory  deposits  in  different  diatheses,  correspond  very 
generally  and  closely  with  those  of  the  coagula  found  in  the  healthy  fibrine,  from 
heart  and  pulmonary  vessels  after  death.  The  results  of  Mr.  exudation  on pericar. 
Paget's  experiments  on  the  same  subject  have  been  already  dium-  Ifc  consists 
cited  (§  212).  And  clinical  observation  fully  confirms  this  °f  "J^01^"6^8 
doctrine  by  evidence  of  another  kind ;  that,  namely,  which  is  bedding"  Numerous 
afforded  by  the  different  course  of  the  same  specific  diseases,  in  corpuscles.] 
different  individuals,  according  to  the  previously  healthy  or  ab- 
normal condition  of  their  blood.  There  can  be  no  doubt  that  a  very  large  pro- 
portion of  what  are  called  '  unhealthy  inflammations,"  especially  those  of  the 
erysipelatous  type,  are  to  be  regarded  as  owing  their  peculiarity  to  a  deficiency  in 
the  due  elaboration  of  the  fibrin,  and  to  the  low  vitality  of  the  cellular  components 
of  the  blood ;  both  of  which  conditions  seem  to  be  favoured  by  the  presence  of 
those  decomposing  matters,  whose  accumulation  in  the  blood  acts  in  many  ways  so 
prejudicially  on  the  system  at  large  (§  226). 2 — That  the  quality  of  the  exudation 
is  in  some  degree  determined  by  the  seat  or  tissue  in  which  the  Inflammation 
occurs,  appears  from  the  different  character  of  the  products  of  the  disordered 
actions,  that  occur  simultaneously  in  different  organs  of  the  same  individual,  and 

1  "Lectures  on  Surgical  Pathologj'",  p.  216,  Am.  Ed. 

2  See  Mr.  Brooke  Gallwev's  papers  on  'Unhealthy  Inflammation,'  in  the  "Lancet"  for 
1849-50,  and  the  "  Medical  Gazette''  for  1850-51. 

23 


254  OF    NUTEITION. 

apparently  under  the  operation  of  the  same  cause ;  thus  it  may  happen  that  in 
pleuro-pneumonia,  the  two  surfaces  of  the  pleura  become  connected  Joy  an  orga- 
nized exudation  of  a  fibrous  character ;  whilst  the  effusion  in  the  substance  of  the 
lung  is  rather  of  the  corpuscular  nature,  and  speedily  passes  into  suppurative 
degeneration.  Mr.  Paget  ingeniously  proposes  to  account  for  the  determining  in- 
fluence in  question,  on  the  idea  that  the  inflammatory  product  is  influenced  at  the 
time  of  its  formation  by  the  assimilative  force  of  each  part,  so  that  it  is  to  be  re 
garded  as  a  mixture  of  true  lymph  with  its  special  product  of  assimilation  ;  thus 
we  observe  that  in  inflammations  of  bone  the  lymph  usually  ossifies,  in  those  of 
ligaments  it  is  converted  into  a  tough  ligamentous  tissue,  and  in  those  of  secreting 
organs  it  contains  a  mixture  of  the  ordinary  secreted  product. — The  mode  in  which 
the  intensity  of  the  Inflammation  affects  the  character  of  the  effused  lymph,  is  two- 
fold. For,  in  the  first  place,  the  nature  of  the  original  effusion  is  likely  to  vary 
according  to  the  degree  in  which  the  ordinary  nutritive  process  is  interrupted ; 
since,  the  more  intense  the  inflammation,  the  less  will  be  the  assimilating  force  of 
the  part,  and  the  more  will  the  matters  effused  from  the  vessels  deviate  from  the 
natural  plasma  which  would  be  drawn  from  them  in  healthy  nutrition  ;  whilst  on 
the  other  hand,  when  the  inflammation  is  less  severe,  its  product  will  not  differ  so 
widely  from  the  natural  one,  and  will  from  the  first  tend  to  manifest  in  its  deve- 
lopment some  characters  corresponding  to  those  of  the  natural  formations  of  the 
part.  But,  secondly,  the  influence  of  the  inflammation,  or  rather  of  the  depressed 
vitality  of  the  inflamed  tissues,  is  shown  in  the  tendency  to  degeneration  which  it 
impresses  on  the  exuded  product;  so  that,  even  though  this  may  be  disposed  to 
pass-on  under  favourable  circumstances  to  the  complete  formation  of  an  organized 
tissue,  its  development  is  early  checked,  and  it  undergoes  retrograde  metamor- 
phosis ;  or  else,  from  the  very  commencement,  its  development  takes  place  accord- 
ing to  a  lower  or  degraded  type.  The  normal  product  of  the  organization  of 
either  fibrinous  or  corpuscular  lymph,  is  undoubtedly  a  tissue  closely  allied  to  the 
ordinary  areolar  or  connective;  it  is  of  this  that  false  membranes  and  adhesions 
are  formed,  and  that  the  material  of  most  thickenings  and  indurations  of  parts 
is  composed ; l  and  it  is  by  the  production  of  this  tissue  also,  that  losses  of  sub- 
stance are  in  the  first  instance  repaired,  and  that  divided  surfaces  are  made  to 
adhere.  Various  kinds  of  degeneration  may  subsequently  take  place  in  any  of 
these  products,  according  to  the  stage  at  which  the  developmental  process  is 
checked;  and  among  these,  in  tissues  which  have  once  attained  an  advanced  stage 
of  development,  the  most  common  is  the  fatty  (§  347). 

375.  But  the  most  frequent  of  all  the  degenerations  of  lymph,  being  almost 
invariable  when  the  lymph  is  placed  from  the  first  in  conditions  unfavourable  to 
its  development,  is  into  the  entirely  unorganizable  or  aplastic  product  which  is 
known  as  Pus.  This,  as  already  mentioned,  is  specially  liable  to  occur  in  lymph 
which  is  originally  rather  corpuscular  than  fibrinous ;  and  every  gradation  may 
be  seen,  from  the  most  characteristic  form  of  the  lymph-cell,  to  that  of  the  pus- 
cell.  But  it  would  seem  as  if  even  the  most  perfectly  fibrinous  lymph  may  pass 
almost  immediately  into  the  condition  of  pus,  when  it  is  effused  among  tissues 
which  are  passing  rapidly  into  a  state  of  decomposition ;  and  thus  it  appears  to 
be,  that  in  a  phlegmonous  inflammation,  the  lymph  effused  into  the  parts  where 
the  inflammatory  process  has  been  most  intense  (the  stagnation  of  the  blood 
being  the  most  complete,  and  the  normal  tissues  most  disposed  to  disintegration), 
does  not  present  the  slightest  tendency  to  a  higher  type  of  organization,  but  is 
developed  from  the  first  in  the  condition  of  pus,  which  fills  the  vacant  space  pre- 
viously occupied  by  living  tissue ;  whilst,  in  the  surrounding  parts,  the  fibrinous 
effusion  produces  a  consolidation  of  the  tissue,  and  thus  forms  the  walls  of  the 

1  The  Author  is  much  disposed,  however,  to  agree  with  Dr.  Handfield  Jones,  in  believing 
that  a  chronic  'fibroid  degeneration,'  resulting  from  the  substitution  of  a  lowly-organized 
fibrous  tissue  for  the  proper  texture  of  the  part,  may  take  place,  like  '  tubercular  degene- 
ration' (|  376),  without  the  occurrence  of  Inflammation,  properly  so  called.     See  "  Brit, 
ad  For.  Med.  Chir.  Rev.,"  vol.  xiii.  pp.  343-349. 


ABNORMAL  FORMS  OF  THE  NUTRITIVE  PROCESS. — TUBERCULOSIS.    355 

abscess,  by  which  the  purulent  effusion  is  limited.  Whether  the  disintegrating 
tissues  are  entirely  removed  by  absorption  (having  previously  undergone  that 
degenerative  softening  which  is  requisite  for  the  occurrence  of  this  process),  or 
whether  they  are  broken-up  and  dissolved  in  the  purulent  fluid,  is  a  point  not 
yet  determined. — The  conservative  nature  of  the  fibrinous  exudation,  and  the 
consequent  importance  of  fibrin  as  an  element  of  it,  are  well  shown  by  the  results 
of  its  deficiency.  Thus  if  there  be  no  'sac'  formed  around  a  collection  of  pus, 
this  fluid  infiltrates  through  the  tissues,  and  by  its  mere  presence  so  impairs  their 
nutrition,  that  a  corresponding  degradation  takes  place  in  the  characters  of  the 
plastic  material  furnished  for  their  assimilation ;  and  hence  the  purulent  effusion 
spreads  without  limit,  and  the  tissues  through  which  it  percolates  undergo  rapid 
degeneration.  So,  again,  when  gangrene  is  spreading  by  contiguity  (the  proxim- 
ity of  the  dead  tissue  tending  to  lower  the  vitality,  and  even  to  occasion  the 
death,  of  that  with  which  it  is  continuous),  it  is  only  when  an  inflammatory  f  re- 
action '  takes  place,  or,  in  other  words,  when  an  exudation  of  fibrinous  lymph  is 
poured  into  the  substance  of  tfre  tissues  bordering  on  those  which  have  lost  their 
vitality,  that  a  line  of  demarcation  between  the  dead  and  the  living  parts  is 
formed.  And  generally  it  may  be  said,  that,  as  the  ultimate  tendency  of  Inflam- 
mation is  to  produce  the  disintegration  of  the  part,  the  ultimate  tendency  of  the 
fibrinous  exudation  is  to  keep  its  elements  together,  and  to  repair  the  losses  which 
have  taken  place,  although  with  a  very  inferior  material.  —  It  is  only,  however, 
with  the  subsidence  of  the  inflammation,  and  the  return  to  the  ordinary  type  of 
nutrition,  that  the  highest  development  of  the  lymph  can  take  place ;  and  it  is 
in  proportion  as  this  occurs  more  speedily,  that  the  recovery  of  the  organization 
proper  to  the  part  is  more  completely  effected.1 

376.  In  persons  of  that  peculiar  constitution,  which  is  termed  Scrofulous  or 
Strumous,  we  find  an  imperfectly-organizable  or  caco-plastic  deposit,  or  even  an 
altogether  aplastic  product,  known  by  the  designation  of  Tubercular  matter, 
frequently  taking  the  place  of  the  normal  elements  of  tissue;  both  in  the  ordi 
nary  process  of  Nutrition,  and  still  more  when  Inflammation  is  set-up.  From 
an  examination  of  the  Blood  of  tuberculous  subjects,  it  appears  that  although 
the  bulk  of  the  coagulum  obtained  by  stirring  or  beating  it  is  usually  greater 
than  that  of  healthy  blood,  yet  this  coagulum  is  not  composed  of  well-elaborated 
Fibrine ;  for  it  is  soft  and  loose,  and  contains  an  unusually-large  number  of 
Colourless  corpuscles,  whilst  the  Red  corpuscles  form  an  abnormaliy-small  pro- 
portion of  it.  We  can  understand,  therefore,  that  such  a  constant  deficiency  in 
plasticity  must  affect  the  ordinary  nutritive  process ;  and  that  there  will  be  a  lia- 
bility to  the  deposit  of  cacoplastic  products,  instead  of  the  normal  elements  of 
tissue,  even  without  inflammation.  Such  appears  to  be  the  history  of  the  forma- 
tion of  Tubercles  in  the  lungs  and  other  organs,  when  it  occurs  as  a  kind  of 
metamorphosis  of  the  ordinary  Nutritive  process;  and  in  this  manner  it  may 
proceed  insidiously  for  a  long  period,  so  that  a  large  part  of  the  tissue  of  the 
lungs  shall  be  replaced  by  tubercular  deposit,  without  any  other  ostensible  sign 
than  an  increasing  difficulty  of  respiration.  In  the  different  forms  of  tubercular 
deposit,  we  see  the  gradation  most  strikingly  displayed,  between  the  plastic  and 
the  aplastic  formations.  In  the  semi-transparent,  miliary,  grey,  and  tough 
yellow  forms  of  Tubercle,  we  find  traces  of  organization  in  the  form  of  cells  and 
fibres,  more  or  less  obvious  (Fig.  91) ;  these  being  sometimes  almost  as  perfectly 
formed  as  those  of  plastic  lymph,  at  least  on  the  superficial  part  of  the  deposit, 
which  is  in  immediate  relation  with  the  living  structures  around ;  whilst  they 

1  The  Author  has  pleasure  in  referring  to  Mr.  Paget's  "  Lectures  on  Surgical  Pathology" 
as  containing,  in  his  opinion,  the  best  exposition  of  the  subject  of  Inflammation  yet  made 
public;  and  in  acknowledging  his  obligations  to  them  for  much  assistance  in  the  short  view 
of  it  given  above. — The  fundamental  principles  on  which  the  Author  would  lay  the  great- 
est stress,  however,  are  the  same  in  all  essential  particulars  with  those  which  he  taught  in 
the  earlier  Editions  of  this  Treatise. 


356  OF    NUTRITION. 

may  be  so  degenerated,  as  scarcely  to  be  distinguishable.  In  no  instances  do 
such  deposits  ever  undergo  further  organization ;  and  therefore  they  must  be  re- 
garded as  caco-plastic.  But  in  the  opaque,  crude,  or  yellow  Tubercle,  we  do  not 
find  even  these  traces  of  definite  structure ;  for  the  matter  of  which  it  consists  is 
altogether  granular,  more  resembling  that  which  we  find  in  an  albuminous 
eoagulum  (Fig.  92).  This  is  entirely  aplastic.  The  larger  the  proportion  of 

[Fie.  91.  [FIG.  92. 


Gray  tubercle;  miliary  granulations.]  Yellow  tubercle;  crude  mass.] 

this  kind  of  matter  in  a  tubercular  deposit,  the  more  is  it  prone  to  soften;  whilst 
the  semi- organized  tubercle  has  more  tendency  to  contraction. — It  may  be  ques- 
tioned, however,  whether  Tubercular  matter  is  not  always,  even  in  its  most  amor- 
phous state,  a  product  of  cell-formation;  and  whether  the  difference  between  the 
amount  of  organization  which  its  several  forms  present,  is  not  due  rather  to  a 
variation  in  the  degree  of  its  subsequent  degeneration,  than  to  an  original  diver- 
sity in  histological  condition.  On  this  view,  Tubercle  is  to  be  considered  as  a 
formation  sui  generis,  whose  production  is  dependent  upon  a  special  taint  in  the 
blood  ;  and  just  as  the  normal  lymph-products  vary  greatly  in  their  degree  of 
vitality,  so  that  some  undergo  a  progressive  and  others  a  retrograde  metamor- 
phosis, so  may  tubercular  deposits  either  retain  their  original  characters  more  or 
less  completely  (though  never  advancing  towards  a  higher  type),  or  may  undergo 
a  very  early  and  complete  degeneration.1 

377.  But  although  Tubercular  matter  may  be  slowly  and  insidiously  deposited, 
by  a  kind  of  degradation  of  the  ordinary  Nutritive  process,  yet  it  cannot  be 
doubted  that  Inflammation  has  a  great  tendency  to  favour  it;  so  that  a  larger 
quantity  may  be  produced  in  the  lungs,  after  a  Pneumonia  has  existed  for  a  day 
or  two,  than  it  would  have  required  years  to  generate  in   the  previous  mode. 
But  the  character  of  the  deposit  still  remains  the  same ;  and  its  relation  to  the 
plastic  element  of  the  blood  is  shown  by  the  interesting  fact,  of  no  unfrequent 
occurrence, — that,  in  a  Pneumonia  affecting  a  tuberculous  subject,  plastic  lymph 
is  often  thrown  out  in  one  part,  whilst  tubercular  matter  is  deposited  in  another. 
Now  Inflammation,  producing  a  rapid  deposition  of  tubercular  matter,  is  pecu- 
liarly liable  to  arise  in  organs,  which  have  been  previously  affected  with  chronic 
tubercular  deposits,  by  an  impairment  of  the  process  of  textural  Nutrition ;  for 
these  deposits,  acting  like  foreign  bodies,  may  of  themselves  become  sources  of 
irritation;  and  the  perversion  of  the  structure  and  functions  of  the  part  renders 
it  peculiarly  susceptible  of  the  influence  of  external  morbific  causes. 

378.  We  frequently  meet  with  abnormal  growths  of  a  Fatty,  Cartilaginous, 
Fibrous,  or  even  Bony  structure ;  which  result  from  the  development  of  these 
tissues  in  unusual  situations,  and  appear  to  originate  in  some  perverted  action  of 
fche  parts  themselves  (§§  353,  374  note). — But  there  is  another  remarkable  form 

1  See  Mr.  Paget  in  the  "  Pathological  Catalogue  of  the  Hunterian  Museum,"  vol.  i.. 
p    134;  also  Dr.  Madden's  "Thoughts  on  Pulmonary  Consumption." 


OF     SECRETION    IN     GENERAL.  35 1 

of  disordered  Nutrition,  which  is  concerned  in  producing  what  have  been  termed 

Tieterologous  growths ;  that  is,  masses  of  tissue  that  differ  in  character  from  any 

which  is  normally  present  in  the  body.     Most  of  these  are  included  under  the 

general  designation  of  Cancerous  or  Fungous  structures;  and  it  has  been  shown 

by  Miiller  and  succeeding  inquirers,  that  the  new 

growth    consists    of  a   mass    of    cells    (Fig.   93); 

which,  like  the  Vegetable  Fungi,  develope  them-         Mi^  \      ^(~<&-, 

selves  with  great  rapidity,  and  which  destroy  the 

surrounding  tissues  by  their  pressure,  as  well  as  by 

abstracting  from  the  Blood  the  nourishment  which     w^ 

was  destined  for  them.     These  parasitic  masses  have     V'.,^  ^ 

a  completely  independent  power  of  growth  and  re- 

,  .    S        c   ,,  ,  Cancer  cell?,  before  and   after 

production ;  and  some  kinds  of  them  can  be  propa-        the  addition  of  acetic  acid.] 
gated  by  inoculation,  which  conveys  into  the  tissues 

of  the  animal  operated-on,  the  germs  of  the  peculiar  cells  that  constitute  the 
morbid  growth,  these  soon  developing  themselves  into  a  new  mass.  So  it  may 
be  by  the  diffusion  of  the  germs  produced  in  one  part,  through  the  whole  fabric, 
by  means  of  the  circulating  current,  that  the  tendency  to  re-appearance  (which 
is  one  great  feature  in  the  malignant  character  of  these  diseases)  is  occasioned. 
But  it  would  seem  more  probable,  that  this  character  rather  depends  upon  the 
presence  of  a  morbid  matter  in  the  blood,  of  which  the  formation  of  the  Can- 
cerous tissue  is  only  the  manifestation  (§  340  note) ;  the  local  disease  thus  being 
the  consequence  of  a  constitutional  cachexia,  rather  than  the  constitutional  affec* 
tion  the  result  of  the  local  disease.1 


CHAPTEK  IX. 

OF    SECRETION   AND   EXCRETION. 

1. —  Of  Secretion  in  General. 

379.  THE  literal  meaning  of  the  term  Secretion  is  separation;  and  this  is 
nearly  its  true  acceptation  in  Physiology.  But  the  ordinary  processes  of  Nutri- 
tion involve  a  separation  of  certain  of  the  components  of  the  Blood,  which  are 
withdrawn  from  it  by  the  appropriating  power  of  the  solid  textures;  and  every 
such  removal  may  be  considered  in  the  light  of  an  act  of  excretion,  so  far  as  the  blood 
and  the  rest  of  the  organism  are  concerned  (§  217.)  Moreover,  the  separation 
of  certain  matters  from  the  blood  in  a  fluid  state,  either  for  the  purpose  of  being 
cast-forth  from  the  body,  or  of  being  employed  for  some  special  purpose  within  it, 
which  constitutes  what  is  ordinarily  known  as  Secretion,  is  effected  by  an  instru- 
mentality of  the  same  nature  with  that  whose  operation  constitutes  an  essential 
part  of  the  nutritive  process ;  namely,  the  production  and  subsequent  agency  of 
cells.  Hence  there  is  no  other  fundamental  difference  between  the  two  processes, 
than  such  as  arises  out  of  the  diverse  destinations  of  the  separated  matters,  and 
from  the  anatomical  arrangements  which  respectively  minister  to  these.  For 
the  products  of  the  Secreting  action  are  all  poured-forth,  either  upon  the  external 
surface  of  the  body,  or  upon  the  lining  of  some  of  the  cavities  which  communicate 
with  it;  and  the  cells  by  which  they  are  separated  from  the  blood,  usually  stand 
in  the  relation  of  epithelium-cells  to  those  prolongations  of  the  skin  or  of  mucous 
membranes,  that  form  the  follicles  or  extended  tubuli  (Fig.  94)  of  which  the 
Glandular  organs  are  for  the  most  part  composed  (Figs.  96,  112).  The  act  of 
Secretion  appears  to  consist,  in  some  cases,  in  the  successive  production  and  exu- 

1  See  Dr.  Walshe  on  "The  Nature  and  Treatment  of  Cancer;"  Mr.  Simon's  "General 
Pathology,"  Lect.  viii.,  Am.  Ed.;  and  Mr.  Paget's  "Lectures  on  Surgical  Pathology," 
Lect.  xiv.,  Am.  Ed. 


358 


OF  SECRETION  AND  EXCRETION. 


viation  of  the  cells  which  minister  to  it,  these  cells  giving-up,  by  rupture  or  deli- 
quescence, the  substances  which  they  have  eliminated  from  the  blood ;  such,  for 

example,  appears  to  be  the  mode 

[Fro.  94. 

A 

2 


of  separation  of  the  Sebaceous  se- 
T     cretion  of  the  skin,  of  the  Mucous 


secretion  of  mucous  membranes, 
of  the  secretion  of  Milk,  and  per- 
haps also  of  the  Biliary  secretion. 
On  the  other  hand,  there  can  be 
little  question  that  those  more 
liquid  secretions,  in  which  there  is 
very  little  solid  matter  (as  is  the 
case  with  the  Cutaneous  transpira- 
tion and  the  Lachrymal  fluid),  or 
in  which  the  solids,  though  in 
larger  amount,  are  in  a  state  of 
such  perfect  solution  as  to  be  capa- 
ble of  easy  transudation  (as  is  the 
case  with  the  Urine),  are  not 
formed  in  this  mode ;  since  neither 
are  exuviated  cells  normally  found 
in  the  secreted  fluids,  nor  do  the 
epithelial  cells  lining  the  glandular 
tubes  or  follicles  present  indica- 
tions of  being  in  a  state  of  con- 
tinual change.  Still,  even  in  these 
cases,  it  seems  fair  to  conclude  that 
the  selective  powers  of  the  gland- 
cells  are  employed  in  drawing  from 
the  blood,  on  one  side,  the  special 
products  which  are  to  be  set-free 
by  transudation  on  the  other. 
Each  group  of  cells  is  thus  adapted 
to  separate  a  product  of  some  par- 
ticular kind,  which  constitutes  its 
special  pabulum  ;  and  the  rate  of 
Plan  of  extension  of  secreting  membrane,  by  inver-  its  production  seems  to  depend, 
uion  or  recession  in  form  of  cavities. — A,  Simple  glands,-  cseteris  paribus,  upon  the  amount 
a,  basement  membrane  ;  6,  epithelial  layer  of  secreting  of  that  pabulum  Supplied  by  the 
cells;  c,  layer  of  capillary  vessels;  g,  follicle;  h,  folli-  circulating  fluid.  The  Substances 
cle  dilated  into  a  sacculus;  ,',  follicle  lengthened  into  a  af.  the  ex  of  which  the  secre. 

tubule,  which  is  coiled  up. — B. Multilocular  crypts;  fc.     .  ,,  *  , 

of  tubular  form;  I,  saccular.lc,  Racemose  or  vesicu-  J^g  cells  grow,  however,  may  not 
lar  compound  glands;  m,  entire  gland,  'showing  be  precisely  those  which  are  SUDSe- 
branched  duct  and  lobular  structure ;  n,  a  lobule  de-  quently  cast-forth  •  for  it  is  very 
tached,  with  o,  branch  of  duct  proceeding  from  it. — D,  probable  that  some  of  them,  at 

Compound  Tubular  gland.]  jeast)  undergo  a  certain  degree  of 

chemical  transformation  by  the  agency  of  these  cells ;  the  characteristic  mate- 
rials of  the  several  secretions  not  being  always  found  to  pre-exist  as  su-ch  in  the 
blood. 

380.  A  distinction  may  be  drawn  as  regards  this  point,  between  those  Excre- 
tions, the  retention  of  whose  material  in  the  Blood  would  be  positively  injurious, 
and  those  Secretions,  which  are  destined  for  particular  purposes  within  the  sys- 
tem, and  the  suspension  of  which  has  no  immediate  influence  on  any  other  func- 
tions than  those  for  which  they  are  respectively  destined.  The  solid  matter  dis- 
solved in  the  fluids  of  the  latter  class,  is  little  else  than  a  portion  of  the  nutritive 
constituents  of  the  Blood ;  either  so  little  altered  as  still  to  retain  its  nutritive 


OF    SECRETION    IN    GENERAL.  359 

character,  as  is  the  case  with  the  casein  of  Milk,  and  with  the  albuminous  con- 
stituent of  the  Serous  fluid  of  areolar  tissue  and  of  serous  and  synovial  membranes; 
or  in  a  state  of  incipient  retrograde  metamorphosis,  as  seems  to  be  the  case  with 
the  peculiar  '  ferments'  of  the  salivary,  gastric,  pancreatic,  and  intestinal  secre- 
tions. On  the  other  hand,  the  characteristic  ingredients  of  the  Excretions  arc- 
very  different  in  character  from  the  normal  elements  of  the  blood.  They  are  all 
of  them  completely  unorganizable ;  and  they  possess,  for  the  most  part,  a  simple 
atomic  constitution.  Some  of  them  also,  have  a  tendency  to  assume  a  crystalline 
form ;  which,  as  Dr.  Prout  justly  remarked,  indicates  their  unfitness  to  enter  into 
the  composition  of  organized  tissues.  With  regard  to  some  of  the  chief  of  these, 
there  is  sufficient  evidence  of  their  existence,  in  small  quantity,  in  the  circulating 
Blood;  but  it  is  also  clear,  that  they  exist  there  as  products  of  decomposition, 
and  that  they  are  destined  to  be  separated  from  it  as  speedily  as  possible.  If 
their  separation  be  prevented,  they  accumulate,  and  communicate  to  the  circu- 
lating fluid  a  positively  deleterious  character.  Of  this,  we  have  already  seen  a 
striking  example  in  the  case  of  Asphyxia  (§  327);  and  the  history  of  the  other 
two  principal  excretions,  the  Bile  and  Urine,  will  furnish  evidence  to  the  same 
effect. — As  a  general  fact,  then,  it  may  be  affirmed,  that  the  materials  of  the 
proper  Excretions  pre-exist  in  the  Blood,  in  a  state  nearly  resembling  that  in 
which  they  are  thrown-off  by  the  secreting  organs;  and  that,  as  their  presence 
there  is  the  result  of  the  destructive  changes  that  have  taken  place  in  the  system, 
they  cannot  be  retained  in  it  without  injury :  but  that  the  materials  of  those 
Secretions  which  are  destined  to  perform  some  particular  function  within  the 
economy,  are  derived  from  the  nutritive  substances  which  are  appropriated  to  its 
general  purposes. 

881.  The  composition  and  uses  of  the  principal  Secretions  which  are  elaborated 
for  special  purposes  within  the  economy,  have  already  been  partly  described  in 
connection  with  the  functions  to  which  they  respectively  minister;  and  the 
remainder  will  hereafter  come  under  notice  in  the  same  manner :  it  is  here 
intended,  however,  to  consider  that  important  system  of  Excretory  operations, 
which  serves  to  maintain  the  purity  of  the  circulating  fluid.  The  process  of 
Respiration,  as  already  pointed-out  (§  283),  is  in  part  to  be  regarded  as  one  of 
these ;  though  the  peculiar  manner  in  which  it  ministers  to  the  removal  of  carbon 
and  hydrogen  from  the  system,  and  its  subserviency  to  other  purposes,  have 
necessitated  its  separate  consideration.  It  is  obvious  that  the  demand  for  the 
performance  of  these  Excretory  processes  generally  will  arise,  in  the  first  place,  as 
in  the  case  of  Respiration,  from  the  continual  disintegration  and  decay  to  which 
the  several  parts  of  the  organized  fabric  are  liable,  in  varying  degrees,  in  the 
maintenance  of  a  merely  vegetative  existence  (§  26) ;  and  this  will  be  constant 
during  the  whole  life  of  Man,  as  of  any  other  warm-blooded  animal,  its  amount 
varying  with  the  degree  of  general  vital  activity. — But,  secondly,  the  exercise  of 
the  animal  functions,  involving  (as  this  does)  the  disintegration  of  the  Nervous 
and  Muscular  tissue  as  the  very  condition  of  the  evolution  of  their  respective 
forces,  becomes  a  special  source  of  the  production  of  excrementitious  matter,  the 
amount  of  which  will  vary  with  that  of  the  forces  thus  developed  (§  22). — The 
removal  of  excrementitious  matter  may  become  necessary,  thirdly,  from  the  decom- 
position of  superfluous  aliment,  which  has  never  been  assimilated.  This  would 
not  be  the  case,  if  the  amount  of  food  prepared  by  the  digestive  process,  and 
taken-up  by  absorption  into  the  current  of  the  circulation,  were  always  strictly 
proportioned  to  the  demand  for  nutriment  created  by  the  wants  of  the  system  , 
but  such  a  limitation  seldom  exists  practically,  in  those  individuals  at  least  who 
do  not  feel  themselves  obliged  to  put  a  restraint  upon  the  indulgence  of  their 
ordinary  appetite ;  and  all  that  is  not  appropriated  to  reparation  of  the  waste,  or 
to  the  increase  of  the  bulk  of  the  body,  must  be  thrown-off  by  the  excretory 
organs.  It  has  been  already  shown,  that  an  abundance  of  nutritive  material  in 
the  blood  does  no*  augment  the  production  of  the  principal  tissues  to  any  con- 


360 


OF  SECRETION  AND  EXCRETION. 


siderable  extent  (353)  }  and  it  would  appear  that  all  such  materials  as  are  not 
speedily  assimilated,  pass  rapidly  into  a  state  of  retrograde  metamorphosis.  How 
large  a  proportion  of  the  solid  matters  of  the  urine,  ordinarily  has  this  source, 
will  appear  from  facts  hereafter  to  be  stated  (§  411).  Moreover,  in  the  last 
place,  it  cannot  be  deemed  improbable  that  the  changes  which  the  crude  aliment 
undergoes,  from  the  time  of  its  first  reception  into  the  absorbents  and  blood- 
vessels, to  that  of  its  conversion  into  organized  tissues  and  special  secretions, 
involve  the  liberation  of  many  products,  of  which  the  elements  are  superfluous, 
and  therefore  injurious  to  the  system  if  retained  in  it.  Thus  it  has  been  shown1 
to  be  quite  possible,  that,  in  the  production  of  Glutin  (gelatin)  from  Albumen, 
an  equivalent  of  Choleic  (tauro-cholic)  acid  may  be  generated.  The  condition  of 
Organic  Chemistry,  however,  is  not  yet  such  as  to  allow  of  anything  being 
advanced  with  certainty  under  this  head. — From  these  various  sources,  then,  a 
large  amount  of  effete  matter  is  being  continually  received-back  from  the  tissues 
into  the  current  of  the  circulation,  or  is  gent-rated  in  the  blood  by  the  changes 
to  which  it  is  itself  subject ;  and  it  is  the  great  object  of  the  Excretory  appa- 
ratus, to  free  that  fluid  from  the  products  which  would  rapidly  accumulate  in  it, 
and  which  would  then  exert  a  poisonous  influence  on  the  body  generally,  were  it 
not  for  the  provision,  which  is  thus  made  for  their  removal. 

382.  The  true  Secreting  processes  which  are  to  be  regarded  as  more  or  less 
completely  excretory,  are  the  separation  of  bile  by  the  Liver,  that  of  Urine  by 
the  Kidneys,  that  of  perspiration  by  the  Skin,  and  possibly  that  of  faecal  matter 
by  the  glandulge  of  the  Intestinal  surface.  The  sum-total  of  these,  with  the 
addition  of  the  carbonic  acid  and  watery  vapour  exhaled  from  the  Lungs,  and  of 
the  indigestible  matter  rejected  in  the  form  of  faeces,  must  be  equal  to  the  total 
amount  of  the  solid  and  fluid  ingesta,  and  of  the  oxygen  which  disappears  from 
the  inspired  air;  the  weight  of  the  body  remaining  the  same.  Now  the  quan- 
tity and  ultimate  composition  of  the  urine  may  of  course  be  exactly  determined, 
as  may  also  that  of  the  faeces :  the  quantity  of  carbonic  acid  thrown-oif  by  the 
lungs,  and  of  oxygen  absorbed,  may  also  be  ascertained  with  a  near  approach  to 
exactness.  Hence,  if  we  add-together,  on  the  one  hand,  the  solid  and  fluid  in- 
gesta, and  the  oxygen  which  has  disappeared  from  the  atmosphere,  and  deduct 
from  this  the  sum  of  the  urinary  and  faecal  discharges  and  of  the  carbonic  acid 
exhaled,  the  difference  (allowance  being  made  for  any  alteration  in  the  weight  of 
the  animal)  will  give  the  amount  of  aqueous  fluid  lost  by  cutaneous  and  pulmo- 
nary transpiration  ;  and  the  proportions  of  the  several  elements  of  the  food  which 
pass-off  by  each  channel,  may  thus  be  calculated  with  considerable  accuracy. 

3-83.  Several  series  of  observations  of  this  kind  have  been  recently  made ; 
some  of  the  most  important  results  of  which  will  here  be  stated. — The  following 
estimate,  deduced  by  Bidder  and  Schmidt2  from  their  observations  upon  a  full- 
grown  Cat,  which  was  allowed  for  a  week  as  much  meat  as  it  could  eat,  shows  the 
mode  in  which  the  constituents  of  the  ingesta  are  distributed  through  the  excre- 
tions of  Carnivorous  animals  : — 


Of  100  parts  of 

d 

i 

Faces. 

Urine. 

Pulmonary  and 
Cutaneous  Exhalation. 

Water  

ta 
o> 

1  *2  per  cent 

82-9  per  cent. 

1  5*9  per  cent 

Carbon    .     .  . 

'fcO 

1*2 

9-5 

89-4      " 

Hydrogen  

\.  *. 

I'l 

23-2 

75-6      " 

« 

0-2 

99-1 

0-7      " 

Oxvsren 

£ 

0-2 

4-1 

95-7      " 

Sulphur    

h 

50-0 

50-0 

gaits  

jq 

92-9 

7-1 

H 

1  See  Prof.  Lie  rig's  "Familiar  Letters  on  Chemistry,"  p.  489. 

9  See  their  elaborate   "  Verdauungssafte   und   Stoffwechsel,"  g  289—413;    also    Prof 
Lehmann's  "  Physiologischen  Chemie,"  2nd  edit.,  band  in.,  p.  370. 


OF    SECRETION    IN    GENERAL. 


361 


In  striking  contrast  with  this,  we  find  the  distribution  of  the  constituents  of  the 
food  of  Herbivorous  animals,  as  deduced  by  Valentin  from  the  observations  of 
Bouissingault  upon  a  Horse,1  to  be  as  follows  : — 


Of  100  parts  of 

a 

5fc! 
0 

Faces. 

Urine. 

Pulmonary  and 
Cutaneous  Exhalation. 

Water  

(2 

03 

61  -8  per  cent. 

5-9  per  cent. 

32-3  per  cent. 

34-6 

2-7       " 

62-7      « 

Hydrogen   

•  «'  • 

40-3 

2-5      " 

67-2      « 

5 

55-7 

27-1       " 

17-2      « 

Oxvfiren 

}£• 

41-4 

1-0      " 

67-6      " 

Ash  

ft 

85-5 

16-2      «« 

The  food  generally 

e 

55-3 

5-2       " 

89-5      « 

The  first  and  most  remarkable  feature  of  difference  between  these  two  sets  of 
results,  is  the  very  large  proportion  which  the  faecal  discharges  of  the  Horse  bear 
to  the  other  excretions ;  this  obviously  proceeds  from  the  indigestibility  of  a  large 
part  of  the  alimentary  substances  it  consumes.  Of  the  water  taken  into  the 
alimentary  canal  or  formed  within  the  body,  nearly  two-thirds  passes-oiF  with  the 
faeces  in  the  Horse,  whilst  nearly  the  whole  is  absorbed  in  the  Cat :  and  of  that 
which  is  absorbed  by  the  Horse,  little  more  than  one-seventh  passes  into  the 
urine,  the  remainder  being  exhaled  from  the  lungs  and  skin  ;  whilst  in  the  Cat, 
the  proportion  which  passes-off  by  the  skin  is  less  than  one-sixth  of  that  which 
is  absorbed,  the  remainder  being  eliminated  by  the  urine.  Of  the  carbon  taken 
into  the  system,  a  relatively-larger  proportion  passes-off  by  the  lungs  in  the 
Horse,  while  a  relatively-larger  proportion  enters  the  urine  in  the  Cat :  this  is 
probably  because  the  great  bulk  of  the  carbon  in  the  food  of  the  Horse  exists  in 
those  non-azotized  compounds,  which  can  be  readily  converted  by  oxygenation 
into  carbonic  acid  and  water,  and  which  consequently  yield  little  or  nothing  to 
the  urine;  whilst  those  products  of  the  decomposition  of  albuminous  substances 
which  pass  into  the  urine,  though  especially  rich  in  nitrogen,  carry  with  them  a 
certain  measure  of  carbon  into  that  excretion.  It  is  probably  for  the  same 
reason,  that  the  amount  of  hydrogen  is  relatively  larger  in  the  pulmonary  exha- 
lation of  the  Horse,  and  in  the  urinary  excretion  of  the  Cat.  On  the  other 
hand,  we  see  that  whilst  the  nitrogen  of  the  food  is  almost  exclusively  eliminated 
through  the  urine  in  the  Cat,  as  much  as  40  per  cent,  of  that  which  has  been 
absorbed  into  the  system  passes-off  by  the  lungs  and  skin  in  the  Horse.  Nearly 
the  whole  of  the  oxygen,  in  each  case,  passes-off  by  the  lungs ;  the  relatively- 
larger  proportion  in  the  urine  of  the  Cat,  being  due  to  the  greater  amount  of 
those  products  of  decomposition  of  albuminous  substances,  into  which  oxygen 
enters.  That  half  of  the  sulphur  contained  in  the  food  of  Carnivora,  should 
pass  off  in  the  faeces,  in  an  unoxidized  or  imperfectly-oxidized  state,  and  that  the 
other  half  should  be  excreted,  chiefly  in  the  condition  of  sulphates,  formed  by 
the  oxidation  of  the  sulphur,  and  by  its  combination  with  alkaline  bases,  is  a 
fact  of  great  interest,  in  connection  with  the  question  of  the  ultimate  destination 
of  the  bile.  For,  with  the  exception  of  the  small  amount  of  sulphur  contained 
in  the  undigested  residue  of  the  food,  the  sulphur  of  the  faeces  must  be  entirely 
derived  from  the  bile,  of  which  secretion  it  is  an  important  constituent.  But  of 
the  bile  which  is  poured  into  the  alimentary  canal,  a  large  part  is  certainly  re- 
absorbed  (§  117),  its  constituents  being  destined  to  undergo  oxidation,  and  to  be 
eliminated,  for  the  most  part,  by  the  respiratory  process ;  and  it  is  probably  from 
this  re-absorbed  portion  of  the  bile,  that  the  sulphur  of  the  urine  is  derived. 
It  appeared  from  other  experiments  performed  by  Bidder  and  Schmidt,  that, 
when  the  bile  was  not  allowed  to  flow  into  the  intestinal  tube,  but  was  collected 

1  Ann.  de  Chim.  et  de  Phys.,"  torn.  Ixi.,  p.  128;  and  Lehmann,  op.  cit.,  p.  368. 


362 


OF  SECRETION  AND  EXCEETION. 


from  biliary  fistulas,  from  10  to  12  per  cent,  of  the  absorbed  carbon,  and  from 
11  to  13  per  cent,  of  the  absorbed  hydrogen,  passes  into  the  biliary  excretion  : 
neither  the  solids  of  the  faeces,  however,  nor  those  of  the  urine,  were  sensibly 
affected  by  the  abnormal  removal  of  these  constituents,  which  fell  entirely  upon 
the  products  of  respiration,  these  being  diminished  to  that  amount.  Hence  it. 
seems  obvious,  that  although  only  half  of  the  sulphur  is  taken-up  again,  nearly 
the  whole  of  the  hydro-carbonaceous  part  of  the  bile  must  be  re-absorbed,  to  be 
finally  eliminated  by  the  respiratory  process  j  so  that  we  may  consider  the  entire 
of  these  constituents  absorbed  from  the  food,  that  remains  after  the  separation  of 
the  components  of  the  urine,  as  being  finally  separated  from  the  body  by  the 
respiratory  process.  According  to  Bidder  and  Schmidt,  100  parts  of  dry  flesh 
are  decomposed  in  the  living  body,  with  the  co-operation  of  167  parts  of  oxygen 
obtained  from  the  atmosphere,  into  31  parts  of  urinary  substances,  2  parts  of 
faecal  matter,  182  parts  of  carbonic  acid,  and  52  parts  of  aqueous  vapour. 
Nearly  the  same  relative  proportions  are  presented  when  the  waste  of  tissues  is 
not  supplied  by  new  alimentary  matter,  as  exist  when  the  animal  is  kept  on  a 
flesh-diet;  so  that  we  may  regard  these  as  representing  the  destination  alike  of 
the  products  of  the  ultimate  metamorphosis  of  the  tissues  of  the  living  body, 
and  that  of  the  products  of  decomposition  of  superfluous  or  unassimilated  aliment 
of  the  Carnivorous  animal.  In  the  Herbivorous  animal,  on  the  other  hand,  only 
a  small  part  of  whose  aliment  is  albuminous  in  its  composition,  the  proportion 
just  stated  will  apply  only  to  that  part,  and  to  the  products  of  the  ultimate  meta- 
morphosis of  its  tissues ;  since  the  whole  of  the  hydrocarbonaceous  components 
of  its  food,  whether  saccharine  or  oleaginous,  are  eliminated  by  the  pulmonary 
and  cutaneous  exhalation. 

384.  The  ultimate  distribution  of  the  components  of  the  food  of  Man  is  in 
most  respects  intermediate,  as  might  be  anticipated,  between  that  of  the  purely- 
Carnivorous,  and  that  of  the  purely  Herbivorous  animal.  We  have  seen 
(§§  318,  321)  that,  of  the  whole  amount  of  carbon  and  hydrogen  in  the  food, 
about  nine-tenths  are  carried-off  by  the  respiratory  process,  the  remaining  tenth 
being  divided  in  varying  proportion  between  faeces  and  the  urine.  So  with 
regard  to  the  nitrogen  (§  320),  for  every  100  parts  ingested,  only  8-33  parts  are 
ejected  with  the  faeces,  while  42  07  parts  are  excreted  in  the  urine,  and  49-6 
parts  (or  nearly  half)  are  exhaled  through  the  skin  and  lungs.  The  following 
table  gives  the  general  results  of  the  comparison  of  the  matters  assimilated  and 
excreted,  in  each  of  the  cases  formerly  referred-to,  so  that  the  sum  in  each  case 
amounts  to  100  : — 


ASSIMILATED. 

EXCRETED. 

Food. 

Oxygen. 

As  water  ;  by 
exhalation. 

As  carbonic 
add. 

Solid  and  fluid 
excretions. 

In  other 
ways. 

A. 

72-2 

27-8 

33-8 

32-3 

33-2 

0-7 

B. 

75-4 

24-6 

36-1 

28-8 

34-7 

0-4 

C. 

76-7 

23-3 

38-2 

28-3 

33-2 

0-3 

D. 

75-3 

24-7 

14-5 

30-2 

54-6 

0-7 

E. 

72-5 

27-5 

31-0 

31-5 

36-9 

0-8 

385.  The  experiments  of  Bidder  and  Schmidt  further  enable  us  to  form  some 
estimate  of  the  amount  of  the  'change  of  matter/  which  is  required  for  the 
performance  of  the  ordinary  vital  functions.  This  cannot  be  fairly  measured  by 
the  amount  of  excreta  given-off  during  a  given  time,  whilst  no  fresh  aliment  is 
being  introduced }  since  the  performance  of  those  various  operations  of  digestion, 
assimilation,  &c.,  which  are  necessary  preliminaries  to  the  appropriation  of  nutri- 
tive matter  by  the  tissues,  itself  involves  no  inconsiderable  consumption  of  what 
was  previously  existing  in  the  body.  Thus  it  is  estimated  by  Bidder  and  Schmidt, 
that  the  respective  amounts  of  the  various  digestive  fluids  which  are  daily  poured 


OF    SECRETION    IN    GENERAL. 

into  the  alimentary  canal  of  an  adult  man  weighing  14  stone,  is  nearly  as 
follows : 

oz.  grains. 

Saliva 56-8  containing    233  of  solid  matter. 

Bile 56-8          "          1208  " 

Gastric  juice  147-2          "          2976  " 

Pancreatic  fluid  7-1          "  310  " 

Intestinal  juice  7-1          "  46  " 

Thus  4773  grains,  or  nearly  ten  ounces  (troy)  of  solid  matter,  are  separated  from 
the  blood  in  the  digestive  secretions,  for  the  purpose  of  introducing  new  alimen- 
tary materials  of  not  more  than  two  or  three  times  the  amount;  and  thus  we  see 
that  a  large  proportion  of  the  food  ingested  and  assimilated,  must  be  consumed 
in  providing  for  the  introduction  of  a  further  supply,  in  addition  to  that  which, 
when  duly  assimilated,  is  applied  by  the  nutritive  processes  to  the  repair  of  the 
solid  tissues.  Hence  we  can  understand  the  result,  at  first  sight  rather  paradoxi- 
cal, of  the  experiments  of  Bidder  and  Schmidt;  which  lead  to  the  conclusion 
that  although  the  loss  of  weight  sustained  by  an  inanitiated  carnivorous  quadruped 
is  about  2-2  per  cent,  daily,  it  is  by  no  means  sufficient  for  the  sustenance  of  its 
weight  that  this  amount  of  food  should  be  supplied ;  about  twice  as  much,  or  4*4 
per  cent.,  being  required  to  keep-up  its  weight  to  the  regular  standard.  When 
supplied  with  an  unlimited  amount  of  food,  the  same  animal  will  appropriate  no 
less  than  10  or  11  per  cent,  of  its  own  weight  daily.  The  amount  of  oxygen 
daily  consumed  increases  in  like  manner;  being  about  1*5  per  cent,  of  its  own 
weight  in  an  animal  taking  no  food,  1-8  per  cent,  in  an  animal  adequately  sup- 
plied, and  about  4-1  per  cent,  in  an  animal  highly  fed  (§  316  vi.).1 

386.  We  see,  then,  that  whilst  the  total  amount  of  the  excretions  will  ordi- 
narily depend  upon  the  quantity  of  food  ingested  (the  weight  of  the  body  re- 
maining the  same,  and  its  losses  of  substance  being  duly  repaired),  the  relative 
proportion  of  the  different  excretions  will  depend  in  great  part  upon  the  nature 
of  the  food  consumed ;  the  solids  of  the  urinary  excretion  being  especially  aug- 
mented by  an  excess  in  the  albuminous  constituents  of  the  food;  whilst  the 
proportion  of  hydro-carbon  got  rid-of  by  respiration,  is  very  much  raised  by  an 
excess  of  the  saccharine  or  oleaginous.  The  amount  voided  as  faeces  is  almost 
entirely  dependent  upon  the  proportion  of  indigestible  matter  in  the  food. — 
Notwithstanding,  however,  that,  under  ordinary  circumstances,  the  several  parts 
of  the  Excretory  apparatus  are  thus  limited,  each  to  its  own  special  function, 
yet  we  find  that  there  are  certain  complementary  relations  between  them,  which 
make  the  action  of  one  vicarious  to  a  certain  extent  with  that  of  another.  Such 
a  relation  seems  to  exist,  for  instance,  between  the  Lungs  on  one  side,  and  the 
Liver  and  Intestinal  glandulse  on  the  other;  for,  the  more  active  the  respiration, 
the  less  bile  is  secreted ;  whilst,  if  the  respiration  be  lowered  in  amount  by  in- 
activity of  body  and  a  high  external  temperature,  a  larger  proportion  of  unoxidized 
or  imperfectly-oxidized  excrementitious  matters  accumulates  in  the  blood,  giving 
rise  to  that  augmented  production  both  of  the  biliary  and  of  the  faecal  excretions, 
which  constitutes  diarrhoea.2  And  thus,  on  the  other  hand,  when  the  liver  is  not 
adequately  affecting  the  depuration  of  the  blood  from  the  constituents  of  bile,  an 
augmentation  of  the  respiration  by  active  exercise  in  a  low  temperature  gives 
most  effectual  relief.  —  Still  more  obviously  vicarious,  however,  are  the  Kidneys 
and  the  Skin ;  for  here  we  find  that  not  only  do  the  kidneys  allow  the  transuda- 
tion  of  whatever  superfluous  water  may  remain  in  the  circulating  current,  after  a 
sufficient  amount  has  been  exhaled  from  the  skin  to  keep-down  the  temperature 
of  the  body  to  its  normal  standard,  but  the  skin  actually  assists  in  the  elimina- 

1  Lehmann,  op.  cit.,  band  iii.,  p.  372. 

*  Such  is  probably  the  occasion  of  the  '  bilious  attacks'  and  '  autumnal  cholera'  so  pre- 
valent at  the  close  of  the  summer ;  the  subjects  of  these  being  most  commonly  persons 
who  have  not  reduced  their  consumption  of  food  during  the  warm  season,  in  accordance 
with  the  diminished  demand  for  the  production  of  heat  within  the  body. 


364 


OF    SECRETION    AND     EXCRETION. 


tion  of  one  of  those  products  of  the  metamorphosis  of  the  azotized  tissues,  the 
removal  of  which  has  been  until  recently  considered  as  the  special  function  of 
the  kidney  (§421).  Consequently,  whenever  the  due  action  of  the  skin  as  an 
excreting  organ  is  interfered-with,  it  is  the  kidney  especially  that  will  be  called- 
on  to  take  its  place ;  whilst,  on  the  other  hand,  if  it  be  thought  desirable  to 
relieve  the  kidney,  this  may  be  most  effectually  done  by  stimulating  the  skin  to 
increased  excretory  activity.  —  This  vicariousness  of  function  among  the  Excre- 
tory organs  presents  itself  far  more  remarkably,  however,  in  certain  states  of 
disease ;  in  which  a  complete  '  metastasis  of  secretion'  may  exhibit  itself.  The 
capability  of  one  organ  thus  to  take  upon  itself  the  special  action  of  another, 
appears  to  be  related  to  the  'community  of  function'  existing  in  the  secretory 
surface  among  those  lower  animals,  which  manifest  none  of  the  (  specialization ' 
or  setting-apart  for  particular  offices,  that  we  see  in  the  higher ;  for  it  seems  to 
be  a  general  law  in  Physiology,  that,  even  where  the  different  functions  are  most 
highly  specialized,  the  general  structure  retains,  more  or  less,  that  primitive 
community  of  action  which  characterized  it  in  the  lowest  grade  of  develop- 
ment.1 

387.  It  is  in  regard  to  the  Urinary  excretion,  that  the  evidence  on  this  point 
is  most  complete  ;  for  it  seems  to  be  established  by  a  great  mass  of  observations, 
that  urine,  or  a  fluid  presenting  its  essential  characters,  may  pass-off  by  the 
mucous  membrane  of  the  intestinal  canal,  by  the  salivary,  lachrymal,  and  mam- 
mary glands,  by  the  testes,  by  the  ears,  nose,  and  navel,  by  parts  of  the  ordinary 
cutaneous  surface,  and  even  by  serous  membranes,  such  as  the  arachnoid  tunic 
lining  the  ventricles  of  the  brain,  the  pleura,  and  the  peritoneum.  A  considerable 
number  of  such  cases  was  collected  by  Haller : 2  many  more  were  brought-toge- 
ther  by  Nysten ; 3  more  recently  Burdach  has  furnished  a  full  summary  of  the 
most  important  phenomena  of  the  kind ; 4  and  Dr.  Laycock  has  compiled  a  valu- 
able collection  of  cases  of  urinary  metastasis  occurring  as  complications  of  hysteria.5 
The  following  table  of  cases  referred-to  by  the  last  of  these  authors  will  give 
some  idea  of  the  relative  frequency  of  the  several  forms  of  this  curious  affec- 
tion : — 


Vomit. 

Stool. 

Ears. 

Eyes. 

Saliva. 

Nose. 

Mammae. 

Navel. 

Skin. 

Total. 

34 

20 

4 

4 

5 

3 

4 

24 

17 

125 

It  is  to  be  borne  in  mind,  however,  that  cases  of  hysterical  ischuria  are  frequently 
complicated  with  that  strange  moral  perversion,  which  leads  to  the  most  perse- 
vering and  ingenious  attempts  at  deceit;  and  there  can  be  little  doubt  that  a 
good  many  of  the  instances  on  record,  especially  of  urinous  vomiting,  are  by  no 
means  veritable  examples  of  metastasis. — The  proofs  of  the  fact  we  are  seeking 
to  establish  are,  therefore,  much  more  satisfactory  when  drawn  from  experiments 
upon  animals,  or  from  pathological  observations,  about  which,  from  their  very 
nature,  there  can  be  no  mistake.  Thus  Mayer6  found  that  when  the  two  kidneys 
were  extirpated  in  the  guinea-pig,  the  cavities  of  the  peritoneum  and  the  pleura, 
the  ventricles  of  the  brain,  the  stomach,  and  the  intestinal  canal,  contained  a 
brownish  liquid  having  the  odour  of  urine;  that  the  tears  exhaled  the  same 
odour;  that  the  gall-bladder  contained  a  brownish  liquid  not  resembling  bile; 
and  that  the  testes,  the  epididymis,  the  vasa  deferentia,  and  the  vesiculse  semi- 
See  "Princ.  of  Comp.  Phys.,"  Am.  Ed.  gg  110,  428. 
'  Elementa  Physiologiae,"  torn,  ii.,  p.  370. 

<  Recherches  de  Physiologic  et  de  Chimie  pathologique,"  p.  265. 
<Trait6  de  Physiologic"  (Jourdan's  Translation),  vol.  viii.,  p.  248,  et  seq. 
<Edinb.  Med.  and  Surg.  Journ.,"  1838;  and  "Nervous  Diseases  of  Women,"  p  288- 
'  ZeitBchrift  fur  Physiologic,"  torn.  ii.  p.  270 


OF  SECRETION  IN  GENERAL.  365 

nales,  were  gorged  with  a  liquid  perfectly  similar  to  urine.  Chirac  and  Helvetius 
are  quoted  by  Haller  as  having  tied  the  renal  arteries  in  dogs,  and  having  then 
remarked  that  a  urin'ous  fluid  was  passed-off  from  the  stomach  by  vomiting.  A 
remarkable  case  is  quoted  by  Nysten  from  Zeviani,  in  which  a  young  woman 
having  received  an  incised  wound  on  the  external  genitals,  which  would  not  heal, 
the  urine  gradually  became  more  scanty,  until  none  could  be  passed  even  with 
the  assistance  of  the  catheter ;  at  last  dropsy  supervened,  with  sweats  of  a  urinous 
odour,  and  vomiting  of  a  urinous  fluid,  which  continued  daily  for  thirty-three 
years;  on  post-mortem  examination,  the  kidneys  were  found  disorganized,  the 
right  ureter  entirely  obliterated  and  the  left  nearly  so,  and  the  bladder  contracted 
to  the  size  of  a  pigeon's  egg. — In  some  other  instances,  the  urine  appears  to  have 
been  secreted,  and  then  re-absorbed  in  consequence  of  some  obstruction  to  its  exit 
through  the  urinary  passages.  Thus  Nysten  quotes  a  case  from  Wrisberg,  in 
which,  the  urethra  having  been  partially  obstructed  for  ten  years  by  an  enlarged 
prostate,  the  bladder  was  so  distended  as  to  contain  ten  pounds  of  urine ;  and  the 
serosity  of  the  pericardium  and  of  the  ventricles  of  the  brain  exhaled  a  urinous 
odour.  He  cites  other  instances,  in  which  the  presence  of  calculi  in  the  bladder 
prevented  the  due  discharge  of  the  secretion  ;  and  in  which  a  urinous  liquid  was 
ejected  from  the  stomach  by  vomiting,  or  was  discharged  by  stool.  A  still  more 
remarkable  case  is  recorded,  of  a  girl  born  without  either  anus  or  external  geni- 
tals, who  nevertheless  remained  in  good  health  to  the  age  of  fifteen  years,  passing 
her  urine  from  the  nipples,  and  getting  rid  of  faecal  matters  by  vomiting. — 
There  are  cases,  moreover,  in  which  it  would  seem  that  the  mucous  lining  of  the 
urinary  bladder  must  have  had  a  special  power  of  secreting  urine ;  the  usual  dis- 
charge having  taken  place  to  the  end  of  life,  when,  as  appeared  by  post-mortem 
examination,  the  kidneys  were  so  completely  disorganized  that  they  could  not 
have  furnished  it,  or  had  been  prevented  by  original  malformation,  or  by  ligature 
of  the  urethra,  from  discharging  it  into  the  bladder.  A  considerable  number  of 
these  have  been  collected  by  Burdach.1  In  all  the  older  statements  of  this  kind, 
there  is  a  deficiency  of  evidence  that  the  fluids  were  really  urinous,  urea  not 
having  been  obtained  from  them  by  chemical  analysis,  and  the  smell  having  been 
chiefly  relied-on.  The  urinous  odour,  however,  when  distinct,  is  probably  nearly 
as  good  an  indication  of  the  presence  of  the  most  characteristic  constitutent  of 
human  urine,  as  is  the  appearance  of  the  urea  in  its  separated  form.  The  pas- 
sage of  a  urinous  fluid  from  the  skin,  has  been  frequently  observed  in  cases  in 
which  the  renal  secretion  was  scanty ;  and  the  critical  sweats,  by  which  attacks 
of  gout  sometimes  terminate,  contain  urates  and  phosphates  in  such  abundance  as 
to  form  a  powdery  deposit  on  the  surface. 

388.  The  metastasis  of  the  Biliary  secretion  is  familiar  to  every  practitioner, 
as  being  the  change  on  which  jaundice  is  dependent.  It  is  not,  however,  in 
every  case  of  yellowish-brown  discoloration  of  the  tissues,  that  we  are  to  impute 
such  discoloration  to  the  presence  of  biliary  matter ;  and  we  can  only  safely  do 
so,  when  we  have  at  the  same  time  evidence  of  concurrent  obstruction  of  the 
biliary  apparatus.  The  urinary  apparatus  then  affords  the  principal  channel 
through  which  the  biliary  matter  is  eliminated ;  the  urine  becomes  tinged  with 
the  colouring-principle  of  bile,  being  sometimes  of  a  yellowish  or  orange  hue,  and 
sometimes  of  a  brown  colour  with  a  considerable  sediment;  and  the  presence  of 
the  most  characteristic  constituents  of  the  bile  has  been  determined  in  the  urine. 
The  same  result  presents  itself,  when  the  biliary  duct  has  been  artificially  ob- 
structed by  ligature.  Other  secretions  have  been  found  tinged  with  the  colour- 
ing matter  of  bile  :  thus  the  pancreatic  fluid  has  been  seen  of  a  yellow  colour  in 
jaundice;  and  the  milk  has  presented  not  merely  the  hue,  but  the  characteristic 
bitterness  of  the  biliary  secretion.  The  cutaneous  transpiration  is  not  unfre- 
quently  so  much  impregnated  with  biliary  matter,  as  to  communicate  its  tinge  to 
the  linen  covering  the  skin ;  and  even  the  sputa  of  patients  affected  with  biliou^ 
1  "  Zeitschrift  fiir  Physiologic,"  torn.  ii.  pp.  253,  254. 


366 


OF  SECRETION  AND  EXCRETION. 


fevers  have  been  observed  to  be  similarly  coloured,  and  have  been  found  to  con- 
tain biliary  matter.  The  secretions  of  serous  membranes,  also,  have  been  fre- 
quently seen  to  present  the  characteristic  hue  of  bile ;  and  biliary  matter  has 
been  detected,  by  analysis,  in  the  fluid  of  the  pleural  and  peritoneal  cavities. 
Biliary  matter,  however,  when  unduly  present  in  the  circulating  current,  is  not 
removed  from  it  by  the  secreting  organs  alone ;  for  it  seems  to  be  withdrawn 
also  in  the  ordinary  operations  of  nutrition,  entering  into  combination  with  the 
solid  tissues.  Thus,  in  persons  affected  with  jaundice,  we  find  the  skin,  the  mu- 
cous and  serous  membranes,  the  lymphatic  glands,  the  brain,  the  fibrous  tissues, 
the  cartilages,  the  bones  and  teeth,  and  even  the  hair,  penetrated  with  the 
colouring  matter  of  the  bile,  which  they  must  have  withdrawn  from  the  blood, 
and  which  seems  to  have  a  particular  affinity  for  the  gelatinous  tissues.  It  is 
impossible  at  present  to  say,  however,  to  what  extent  the  more  characteristic 
ingredients  of  the  bile  are  thus  withdrawn  from  the  blood;  for  the  presence  of 
its  colouring  matter  cannot  by  any  means  be  taken  as  an  indication,  that  its 
peculiar  resinoid  acids  are  also  incorporated  with  the  normal  components  of  the 
tissues. 

2.   The  Liver. — Secretion  of  Bile. 

889.  The  Liver  is  probably  more  constantly  present,  under  some  form  or  other, 
throughout  the  entire  Animal  series,  than  any  other  gland.  Its  form  and  condi- 
tion vary  so  greatly,  however,  in  different  tribes,  that,  without  a  knowledge  of  its 
essential  structure,  we  should  be  disposed  to  question  whether  any  identity  of 
character  exists  among  the  several  organs  which  are  regarded  as  Hepatic.  It  is, 
in  fact,  the  presence  of  bile-secreting  cells,  that  must  be  held  to  constitute  a 
Liver;  and  these  may  be  scattered  over  the  general  lining  membrane  of  the 
alimentary  canal,  or  may  be  restricted  within  follicles  which  are  formed  by  de- 
pressions of  it;  these  follicles,  again,  may  be  multiplied  in  some  particular  spot, 
so  as  to  be  aggregated  into  a  mass,  or  may  be  extended  into  long  tubes.  In  all 
the  Invertebrata,  however,  the  Liver  is  obviously  conformable  to  the  general  type 
of  glandular  structures ;  the  hepatic  cells  being  in  immediate  relation  with  a 
basement-membrane,  and  being  discharged  upon  a  free  surface.  This  will  be 
readily  understood  from  an  examination  of  any  one  of  the  higher  forms  of  it, 
such  as  that  presented  in  the  liver  of  the  Crab,  (Fig.  95),  which,  like  the  liver 

FIG.  95. 


Lobule  of  Liver  of  Squilla  Mantis;  A,  exterior j  B,  the  same  cut  open.] 

of  the  Mollusca  generally,  is  a  lobulated  glandular  mass,  formed  by  the  aggrega- 
tion of  a  multitude  of  follicles  with  distinct  caecal  terminations;  these  follicles 
discharging  their  secreted  products  into  cavities  which  occupy  the  centre  of  the 
lobules,  whence  they  are  collected  by  the  ducts  which  convey  them  into  the 
alimentary  canal.  On  a  careful  examination  of  these  follicles  (Fig  96),  and  a 
wmparison  of  the  size  and  contents  of  the  cells  at  the  bottom  and  towards  the 


THE    LIVER.  —  SECRETION    OP    BILE. 


367 


FIG. 


outlet,  it  becomes  evident  that  the  cells  originate  in  the  former  situation,  and 
gradually  increase  in  size  as  they  advance  towards  the 
latter.  It  is  also  to  be  observed  that  the  cells  which 
lie  deepest  in  the  csecurn  (cr,  6),  contain  for  the  most 
part  the  yellow  granular  matter,  which  may  be  re- 
garded as  the  proper  biliary  secretion  ;  but  as  they  in- 
crease in  size,  there  is  also  an  increase  in  the  quan- 
tity of  oil-globules  which  they  contain  (c),  until  past 
the  middle  of  the  follicle,  where  they  are  found  full 
of  oil,  so  as  to  have  the  appearance  of  ordinary  fat- 
cells  (d,  e).  From  this  it  happens,  that  when  an 
entire  caecum  is  examined  microscopically,  its  lower 
half  appears  filled  with  a  finely-granular  matter,  inter- 
mingled with  nucleated  particles ;  and  the  upper  half 
with  a  mass  of  fat-cells,  whose  nuclei  are  obscured  by 
the  oily  particles.1 — In  Vertebrated  animals,  however, 
the  Liver  seems  to  be  constructed  upon  a  different 
plan  :  its  component  cells  are  no  longer  contained  in 
distinct  caecal  follicles  or  elongated  tubuli  branching- 
off  from  the  excretory  ducts,  but  are  clustered  toge- 
ther in  masses  having  no  immediate  relation  to  those 
ducts ;  and  there  appears  strong  reason  to  consider  the 
organ  as  in  great  part  analogous  to  the  Vascular  or 
Ductless  Glands.  In  ascending  through  the  Verte- 
brated series,  it  presents  a  more  and  more  solid  paren- 
chymatous  texture,  which  strikingly  contrasts  with  its  ,  One  of  !he  5?^!  ™c*  f 

iiiii,     i  iii*i  Astacns  afnms  (Cray-fish),  nign- 

loosely- lobulated i  racemose  aspect  in  even  the  highest  ly  magni£ed)  ;howing  the  pro- 
Invertebrata.  This  character  is  very  obvious  in  the  gress  of  development  of  the  se- 
liver  of  Man,  which  is  peculiarly  firm  and  compact,  creting  cells  from  the  blind  ex- 
and  has  less  of  connective  tissue  between  its  different  fremity  to  the  mouth  of  the 

parts,  than  is  found  in  that  of  many  other  Mammalia.  f?u?cle'*  sPecimens  of  thef  in 
T,   .       •,  i  ,  .,    "T-,  ,.  ,         their  successive  stages,are  shown 

—It  is  observable,  moreover,  in  the  Human  liver,  that  separately  at  a,  b,c,  d,  e. 
certain  portions  are  rudimentary,  which  are  elsewhere 

fully  developed.  Thus  in  the  Carnivora  and  Rodentia,  which  present  the  most 
complex  form  of  liver  that  we  meet-with  among  Mammalia,  there  are  five  distinct 
parts ;  namely,  a  '  central '  or  principal  lobe,  and  a  right  and  left  '  lateral '  lobe, 
each  with  its  '  lobular  appendage.'  The  whole  mass  of  the  liver  of  Man  (Fig.  97), 
which  we  are  accustomed  to  describe  as  consisting  of  a  'right'  and  'left'  lobe, 
does  in  reality  form  but  one  (there  being  no  real  division  between  its  two  por- 
tions), which  must  be  regarded  as  the  'central'  lobe;  the  'lobulus  Spigelii'  is 
the  rudiment  of  a  right  'lateral'  lobe,  and  the  'lobulus  caudatus'  is  its  'lobular 
appendage;'  but  the  left  'lateral'  lobe,  with  its  'lobular  appendage,'  is  altogether 
undeveloped.2 

390.  When  the  Liver  is  closely  examined  with  the  naked  eye,  it  is  seen  to  be 
made-up  of  a  great  number  of  small  granular  bodies,  about  the  size  of  millet- 
seeds,  of  an  irregular  form,  and  presenting  a  number  of  rounded  projecting  pro- 
cesses upon  their  surfaces.  These  are  commonly  termed  lobules,  although  by 
some  Anatomists  they  are  spoken-of  as  acini3  WThen  divided  longitudinally, 

1  See  Dr.  Leidy's  'Researches  into  the  Comparative  Structure  of  the  Liver,'  in  "  Amer. 
Journ.  of  Med.  Sci.,"  Jan.  1848. 

3  For  a  general  view  of  the  Comparative  Structure  of  the  Liver  in  different  classes  of 
animals,  see  "  Princ.  of  Comp.  Phys.,"  Am.  Ed.,  \\  405 — 411. 

3  The  acini  of  Malpighi  are  the  minute  bodies  of  various  forms  and  yellowish  colour, 
which  are  seen  when  any  individual  lobule  is  examined  with  the  microscope ;  these  are 
nothing  else,  however,  than  the  irregular  islets  of  parenchyma,  left  between  the  rueshes 
of  the  plexus  formed  by  the  ultimate  ramifications  of  the  portal  vein. 


BtfS 


OF    SECRETION    AND    EXCRETION 

[Fie.  97. 

'"  15 


FIG.  98L 


The  inferior  or  concave  surface  of  the  Liver,  showing  its  subdivisions  into  lobes :  1,  centre  of 
the  right  lobe:  2,  centre  of  the  left  lobe;  3,  its  anterior,  inferior,  or  thin  margin;  4,  its  poste- 
rior, thick,  or  diaphragmatic  portion ;  5,  the  right  extremity  ;  6,  the  left  extremity  ;  7,  the  notch 
in  the  anterior  margin ;  8,  the  umbilical  or  longitudinal  fissure ;  9,  the  round  ligament  or  re- 
mains of  the  umbilical  vein;  10,  tne  portion  of  the  suspensory  ligament  in  connection  with  the 
round  ligament;  11,  pons  hepatis,  or  band  of  liver  across  the  umbilical  fissure;  12,  posterior 
end  of  longitudinal  fissure;  13,  14,  attachment  of  the  obliterated  ductus  venosus  to  the  ascend- 
ing vena  cava;  15,  transverse  fissure;  16,  section  of  the  hepatic  duct;  17,  hepatic  artery;  18, 
its  branches;  19,  vena  portarum ;  20,  its  sinus,  or  division  into  right  and  left  branches;  21, 
fibrous  remains  of  the  ductus  venosus ;  22,  gall-bladder ;  23,  its  neck ;  24,  lobulus  quartus  ;  25, 
lobulus  Spigelii;  26,  lobulus  caudatus ;  27,  inferior  vena  cava;  28,  curvature  of  liver  to  fit  the 
ascending  colon;  29,  depression  to  fit  the  right  kidney;  30,  upper  portion  of  its  right  concave 
surface  over  the  renal  capsule;  31,  portion  of  liver  uncovered  by  the  peritoneum;  32,  inferior 
edge  of  the  coronary  ligament  in  the  liver ;  33,  depression  made  by  the  vertebral  column.] 

they  have  a  somewhat  foliated  appearance  (Fig.  98),  arising  from  the  distribution 

of  the  Hepatic  Vein,  which  passes  into  the 
centre  of  each  division.  When  transversely 
divided,  the  lobules  are  usually  found  to  pre- 
sent somewhat  of  a  pentagonal  or  a  hexagonal 
shape,  the  angles  being  slightly  rounded,  so 
as  to  form  a  series  of  passages  or  interlobular 
spaces  (2  B,  Figs.  106, 109)  :  in  these  lie  the 
branches  of  the  Yena  Portse  (as  well  as  of 
the  Hepatic  Artery  and  Duct),  from  which  are 
derived  the  plexuses  that  enter  the  lobules. 
The  exterior  of  each  lobule  is  covered  by  a 
process  of  the  '  capsule  of  Glisson/  which  is 

™y  d-se  iD  ^  ?* and  »'he.r  ani'?ls' but 

vein  ;  2,  2,  2,  lubules  depending  from  its   1S  so  thm  as  *°  be  *\™OSt  undistmguishable  in 
branches,  like  leaves  on  a  tree;  the  cen-   the    Human    liver;    its  Substance   is   composed 

e  of  each  being  occupied  by  a  venous  of  a  parenchyma  formed  by  a  solid  network 
rig,  the  Intralobular  Vein.  Of  nucleated   cells,  the   interspaces   of  which 

are  occupied  by  the  minute  ramifications  of 
the  before-mentioned  vessels,  arranged  in  the  manner  presently  to  be  described. 
The  structure  of  each  lobule,  then,  gives  us  the  essential  characters  of  the  whole 
gland. 

391.  The  Vena  Portse,  which  is  formed  by  the  convergence  of  the  veins  that 
return  the  blood  from  the  chylopoietic  viscera,  probably  also  receives  the  blood 
which  is  conveyed  to  the  liver  for  the  purposes  of  nutrition  by  the  Hepatic 
Artery.  Like  an  artery,  it  gradually  subdivides  into  smaller  and  yet  smaller 
branches;  and  at  last  it  forms  a  plexus  of  vessels,  which  lie  in  the  inter-lobular 
spaces,  and  spread  with  the  freest  inosculation  throughout  the  entire  Liver.  To 


twig, 


THE  LIVER.  —  SECKETION  OF  BILE. 


369 


FIG.  99. 


these  vessels,  the  name  of  infcr-lobular  Veins  was  given  by  Mr.  Kiernan.1  They 
ramify  in  the  capsules  of  the  lobules,  covering  with  their  ramifications  the  whole 
external  surface  of  these ;  and  then  enter 
their  substance.  When  they  enter  the 
lobules,  they  are  termed  lobular  veins  ; 
and  the  plexus  formed  by  their  conver- 
gence from  the  circumference  of  each 
lobule  towards  its  centre  (where  their  ulti- 
mate ramifications  terminate  in  those  of 
the  intra-lobular  or  hepatic  vein),  is  desig- 
nated as  the  lobular  venous  plexus  (Fig. 
99).  In  the  islets  of  this  plexus  (the 
acini  of  Malpighi),  the  ramifications  of  the 
hepatic  duct  are  distributed,  in  the  manner 
to  be  presently  described.  — The  Hepatic 
Artery  sends  branches  to  every  part  of  the 
Liver,  supplying  the  walls  of  the  portal 
and  hepatic  veins,  and  of  the  hepatic  ducts, 
as  well  as  Glisson's  capsule.  The  princi- 
pal distribution  of  its  branches,  however, 


Horizontal  section  of  three  superficial  Lo- 


is  to  the  lobules;  which  they  reach,  in  the  bules>  showi"g  the  two  principal  systems  of 
same  manner  with  the  portal  vessels  and  *{*«*;<»•?'•  /-1'1  >  ^-lobulai -veins  ter- 
,  «Y.  ,    f      minatmg  in  the  Hepatic  veins;  2,  2,  ^nter- 

bihary    ducts,    by   spreading    themselves  lobular  plexus?  formed  by  branches  of  the 
through  the   interlobular  spaces.     There  Portal  vein, 
they  ramify  upon  the  interlobular  ducts, 

and  upon  the  capsular  surface  of  the  lobules,  which  they  then  penetrate  ;  their 
minuteness  prevents  their  ultimate  distribution  within  the  lobules  from  being 
clearly  demonstrable  ;  but  it  is  probable  that  they  are  for  the  most  part  restricted 
to  the  peripheral  portions  of  these.  As  to  the  ultimate  termination  of  the  ca- 
pillaries of  the  hepatic  artery,  —  whether  they  enter  the  Portal  plexus,  or  the 
Hepatic  Vein, — there  is  a  difference  amongst  anatomists;  the  former  view  being 
upheld  by  Kiernan,  the  latter  by  Miiller.  The  question  is  a  very  interesting  one 
in  a  physiological  point  of  view;  since,  if  the  former  account  be  the  true  one, 
the  blood  which  is  brought  to  the  liver  by  the  hepatic  artery  can  only  become 
subservient  to  the  secretion  of  bile,  by  passing  into  the  portal  plexus;  whilst,  if 
the  latter  be  the  correct  statement,  either  the  arterial  blood  is  not  at  all  subser- 
vient to  the  formation  of  bile,  or  the  secretion  can  be  elaborated  from  the  arte- 
rial capillaries.  The  researches  of  Mr.  Kiernan  have  satisfactorily  proved, 
that  the  intralobular  or  hepatic  veins  cannot  be  filled  by  injection  from  the 
hepatic  artery,  though  they  may  be  readily  filled  from  the  portal  plexus;  whilst, 
on  the  other  hand,  there  is  reason  to  believe,  that  a  very  fine  injection  into  the 
hepatic  arteries  will  find  its  way  into  the  portal  plexus.2  It  is  certain  that  all 
the  branches  of  the  hepatic  artery,  of  which  the  termination  can  be  ascertained, 
end  in  the  vena  portae;  a  free  capillary  communication  existing  between  their 
two  systems  of  branches,  on  the  walls  of  the  larger  blood-vessels  and  ducts. 
According  to  Miiller,  there  is  an  ultimate  plexus  of  capillary  vessels,  with  which 
all  the  three  systems  freely  communicate ;  but  for  this  idea  there  is  no  adequate 
foundation ;  and  it  is  inconsistent  with  the  fact  just  stated,  that  injection  into 
the  hepatic  artery  does  not  return  by  the  hepatic  vein. — It  now  only  remains  to 
describe  the  Hepatic  Veins,  the  branches  of  which  occupy  the  interior  of  the 
lobules,  and  are  termed  •mfrcr-lobular  veins  (Fig.  99,  1,  1,  Fig.  100).  On 
making  a  transverse  section  of  a  lobule,  it  is  seen  that  the  central  vessel  is  formed 

1  See  his  admirable  Memoir  on  «  The  Anatomy  and  Physiology  of  the  Liver,"  in  th« 
"  Philosophical  Transactions,  1833. 

a  This  is  stated  to  have  been  the  case  in  the  injections  of  Lieberkiihn,  although  M* 
Kiernan  has  not  succeeded  in  effecting  it. 
24 


870 


OF  SECRETION  AND  EXCRETION, 
PIG.  100. 


Section  of  a  small  portion  of  the  Liver  of  a  Rabbit,  with  the  Hepatic  or  intralobular 

veins  injected. 

by  the  convergence  of  from  four  to  six  or  eight  minute  venules,  which  arise  from 
the  processes  upon  the  surface  of  the  lobule.  In  the  superficial  lobules  (by 
v^hich  term  are  designated  those  lobules  that  lie  upon  the  exterior  of  the  glan- 
dular substance,  not  only  upon  the  surface  of  the  liver,  but  also  against  the  walls 
of  the  larger  vessels,  ducts,  &c.)  the  intralobular  veins  commence  directly  from 
their  surface ;  and  the  minute  venules  of  which  each  is  composed,  may  be  seen 
in  an  ordinary  injection,  converging  from  the  circumference  towards  the  centre, 
as  in  the  transverse  section  of  other  lobules.  The  intralobular  veins  terminate  in 
the  larger  trunks,  which  pass  along  the  bases  of  the  lobules,  collecting  from  them 
their  venous  blod;  these  are  called  by  Mr.  Kiernan  svb-tobttJar  veins.  The 
main  trunk  of  the  Hepatic  Vein  terminates  in  the  ascending  Vena  Cava. 


[FIG.  101. 


FIG.  102. 


Horizontal  section  of  two  superficial  Lo- 
uules,  showing  the  interlobular  plexus  of 
Biliary  Ducts:  1,  1,  intralobular  veins;  2,  2, 
trunks  of  biliary  ducts,  proceeding  from  the 
plexus  which  traverses  the  lobules;  3,  inter- 
lobular tissue;  4,  parenchyma  of  the  lobules.] 


Diagram  of  the  arrangement  of  the  cellular 
parenchyma  (bb)  of  the  Human  Liver,  with  re- 
ference to  the  radicals  of  the  interlobular  ducts 
(a  a),  and  the  vascular  spaces  (c  c). 


392.  The  Hrpatic,  Duct  forms,  by  its  subdivision  and  ramification,  an  inter- 
lobular plexus  very  like  that  of  the  portal  vein,  (Fig.  101);  but  the  anastomosis 


THE    LIVER.  —  SECRETION    OF    BILE. 


371 


between  the  branches  going  to  the  different  lobules  is  less  intimate  than  that  of 
the  interlobular  veins,  and  cannot  be  directly  demonstrated;  although  Mr.  Kier- 
nan  thinks  that  his  experiments  leave  but  little  doubt  of  its  existence, — a  com- 
munication (which  cannot  be  seen  to  be  established  by  any  nearer  channel),  being 
proved  to  exist  between  the  right  and  left  primary  subdivisions  of  the  duct.  The 
interlobular  ducts  ramify  upon  the  capsular  surface  of  the  lobules,  with  the 
branches  of  the  portal  vein  and  hepatic  artery;  but  they  cannot  be  traced  into 
their  interior;  and  most  recent  observers  agree  in  affirming  that  they  do  not 
enter  their  parenchymatous  substance.  To  use  the  language  of  Prof.  Kolliker,1 
"  Whatever  view  we  may  take  of  the  connection  of  the  hepatic  cell-network  with 
the  efferent  biliary  canals,  it  is  undeniable  that  any  such  connection  only  takes 
place  upon  the  surface  of  the  hepatic  islets  (lobules),  and  not  in  their  interior; 
and  that,  therefore,  the  bile  which  is  formed  there  must  be  transmitted  outwards 
from  cell  to  cell"  in  the  manner  in  which  fluids  are  transmitted  through  closed 
cells  in  plants.  The  probable  relation  of  these  two  components  of  the  Hepatic 
structure,  is  shown  (diagrammatically)  in  Fig.  102. — The  terminal  portions  of 
the  biliary  ducts2  are  crowded  with  nuclear  particles,  and  granular  matter,  resem- 
bling that  which  forms  the  intercellular  plasma  of  the  lobules;  there  are  also 
cells  which  seem  to  be  identical  with  those  of  the  parenchyma,  except  that  their 
walls  are  thinner  and  their  contents  more  pellucid;  and  fragments  of  similar 
cells  are  often  to  be  seen ;  whilst  the  columnar  epithelium  which  lines  the  larger 
ducts,  is  almost  or  entirely  wanting.  These  appearances  may  be  considered  to 
indicate,  that  an  active  secretory  function  is  going-on  in  this  situation. 

393.  The  substance  of  each  lobule  may  be  considered  as  a  solid  network  of 


FJG.  103. 


Fie.  104. 


Fig.  103.  Transverse  section  of  a  Lobule  of  the  Human  Liver,  showing  the  reticular 
arrangement  of  its  parenchyma,  with  some  of  the  branches  of  the  Hepatic  Vein  in  the  centre, 
and  those  of  the  Portal  Vein  at  the  periphery. 

Fig.  104.  A  small  portion  of  this  section  more  highly  magnified,  showing  the  columns  of 
secreting  cells  of  which  the  parenchyma  is  composed. 

parenchyma  (Figs.  103, 104),  composed  of  cells ;  the  interspaces  of  which  are  so 
completely  occupied  by  the  vascular  network  already  described,  that,  when  the 
latter  is  fully  injected,  no  vacuities  are  seen.  The  meshes  of  the  parenchyma- 
tous network  have  a  more  rounded  form  towards  the  margin  of  the  lobule,  whilst 
in  the  centre  they  are  disposed  more  radially;  so  that  in  a  section  cutting  the 
intralobular  veins  transversely,  long  branching  columns  of  hepatic  cells  are  seen 
stretching  from  the  latter  on  all  sides,  and  uniting  by  short  lateral  anastomoses 
(as  in  Fig.  104),  so  that  the  intermediate  meshes  appear  like  narrow  elongated 

1  "  Manual  of  Human  Histology."  (Sydenham  Society's  Edit.),  vol.  ii.,  p.  119. 
*  See  Mr.  Wharton  Jones,  in  "Philos.  Transact.,"  1848,  p.  277 


372 


OF  SECRETION  AND  EXCRETION. 


clefts.  These  columns  (Fig.  105,  A)  usually  consist  of  from  three  to  five  rows 
of  cells,  and  are  generally  cylindrical  or  prismatic,  but  not  at  all  regularly  so. 
Fragments  of  them  are  almost  always  to  be  found  among  scraped-off  particles  of 
the  liver.1 

394.  The  biliary  celh  of  the  Human  liver  (Fig.  105,  B)  are  usually  of  a  flat- 
tened spheroidal  form,  and  from  l-1500th  to  l-2000th  of  an  inch  in  diameter. 

Each  of  them  presents  a 

FIG.  105.  distinct  nucleus ;  and  the 

Qavity  of  the  cell  is  occu- 
pied by  yellow  amor- 
phous biliary  matter, 
usually  having  one  or 
two  large  adipose  glo- 
bules, or  five  or  six  small 
ones,  intermingled  with 
it  (a,  b).  The  size  and 
number  of  these,  how- 
ever, vary  considerably, 
according  to  the  nature 
of  the  food,  the  amount  of 
exercise  recently  taken, 
and  other  circumstances. 
If  an  animal  be  very  fat, 

or  be  well  fed,  especially 
A,  portion  of  a  ffepatie  Column,  from  Human  Liver,  showing  its       -fh    farinnpp  '    ,    nr  ni/ 
component  secreting  cells :— B,  secreting  cells  detached,  a,  in  their  W  . 

normal  state,  6,  a  cell  more  highly  magnified,  showing  the  nucleus   aginoilS    Substances,    the 
and  distinct  oil-particles,  c,  in  various  stages  of  fatty  degeneration,   proportion  of  adipose  par- 
ticles (c)  is  much  greater 

than  in  an  animal  moderately  fed  and  taking  much  exercise.  The  size  of  the 
oil-globules  varies  from  that  of  mere  points,  scarcely  distinguishable  from  the 
granular  contents  of  the  cells  except  by  their  intense  blackness,  up  to  one-fourth 
of  the  diameter  of  the  cell.  A  still  greater  accumulation  of  adipose  particles  in 
the  biliary  cells,  gives  rise,  as  was  first  pointed-out  by  Mr.  Bowman,2  to  the 
peculiar  condition  termed  '  fatty  liver'  (397).  The  finely-granular  matter  is  the 
portion,  from  which  the  colour  of  the  cell  is  derived ;  it  seems  to  fill  the  space 
not  occupied  by  the  oil-globules;  and  it  often  obscures  the  nucleus,  so  that  the 
latter  cannot  be  distinguished  until  acetic  acid  is  added,  which  makes  the  gra- 
nular matter  more  transparent  without  aifecting  the  nucleus. — The  cells  are  im- 
bedded in  a  diffused  granular  plasma,  in  which  young  cells  are  observable ;  these 
being  apparently  formed  by  a  collection  of  free  nuclei.  It  has  been  usually 
supposed  that  the  hepatic  cells  ordinarily  contain  biliary  matter;  but  such,  from 
the  recent  enquiries,  of  Dr.  C.  Handfield  Jones,3  appears  not  to  be  the  case, 
save  in  exceptional  instances,  though  the  colouring  matter  which  they  contain 
seems  to  be  identical  with  that  of  the  bile.  But  the  peculiar  sugar  which  is 

1  This  plexiform  arrangement  of  the  cellular  parenchyma  of  the  Liver,  has  led  several 
eminent  Anatomists  (among  them  Prof.  Retzius,  Dr.  Leidy,  and  Dr.  Guillot)  to  the  belief 
that  the  biliary  ducts  form  a  plexus  through  the  interior  of  the  lobules,  and  that  the  hepatic 
cells  line  their  interior.  Although  he  had  never  been  able  to  confirm  the  statements  of 
these  observers  respecting  the  existence  of  a  basement-membrane  around  the  'columns'  of 
hepatic  cells,  yet  he  was  so  far  satisfied  of  the  correctness  of  their  statements  on  other 
points,  as  to  have  accepted  this  one,  in  former  editions,  without  questioning  its  correctness. 
Further  inquiry,  however,  has  satisfied  him  that  the  view  of  the  compound  nature  of  the 
Hepatic  structure,  which  Dr.  C.  Handfield  Jones  was  the  first  to  propound  ("Philosophical 
Transactions,"  1846,  1849,  and  1853),  and  which  harmonises  with  Prof.  Kolliker's  account 
of  its  structure  (op.  cit.),  is  really  the  correct  one:  this  view,  moreover,  being  strikingly 
confirmed  and  illustrated  by  the  parallel  order  of  anatomical  and  physiological  facts  pre- 
sented by  the  Vascular  Glands. 

"  "Medical  Gazette,"  Jun.  1842.  8  "Philosophical  Transactions,"  1853. 


THE  LIVER.  —  SECRETION  OF  BILE. 


373 


FIG.  106. 


3 


1,  angular  lobules  in  a  state  of  Ancenna, 


found  in  the  blood  of  the  hepatic  vein  (§  185),  is  nearly  always  detectable 
throughout  the  cellular  parenchyma ;  being  least  abundant,  however,  when  the 
cells  are  loaded  with  fat,  which  is  more  commonly  the  case  with  those  of  the 
periphery,  than  with  those  of  the  centre,  of  the  lobules. 

895.  Before  proceeding  to  consider  the  physiological  action  of  this  organ,  we 
may  stop  to  notice  some  of  those  Pathological  changes  occasionally  seen  in  it, 
which  have  a  most  intimate*relation  to  the  structural  details  already  given.  The 
first  class  of  alterations  in  its  appearance  to 
which  we  shall  refer,  is  connected  with 
abnormal  conditions  of  its  Circulation,  as 
was  long-since  discovered  by  Mr.  Kiernan 
(loc.  cit.)  When  the  liver  is  in  a  state  of 
Anaemia  (which  rarely  happens  as  a  natu- 
ral condition,  although  it  may  be  induced 
by  bleeding  an  animal  to  death),  the  whole 
substance  of  the  lobules  is  pale,  as  repre- 
sented in  Fig.  106.  In  general,  however, 
the  liver  is  more  or  less  congested  at  the 
moment  of  death ;  and  this  congestion  may 
manifest  itself  in  several  ways.  The  whole 
substance  may  be  congested  ;  in  which  case 
the  lobules  present  a  nearly-uniform  dark 

colour    throughout    their    substance,    their  ,they  app^ar  on  the  external  surface  of  the 
t_   •     '  ,,  111  T  l^ver:  2.  interlobular  spaces:  3,  mterlobular 

centres  being  usually  more  deeply-coloured  fissur'es  |  4,  interlobuJveins,  occupying  the 
than   the   margins.      An   appearance   more  centres  of  the  lobules ;  5,  smaller  veins,  ter- 
frequently  offered  after  death,  however,  is  minating  in  the  central  veins, 
that  represented  in  Fig.  107,  and  termed 

by  Mr.  Kiernan,  the  first  stage  of  Hepatic  Venous  congestion.  In  this,  the 
isolated  centres  of  the  lobules  alone  present  the  colour  of  sanguineous  congestion; 
and  the  surrounding  substance  varies  from 
a  yellowish-white,  yellow,  or  greenish 
colour,  according  to  the  quantity  and 
quality  of  the  bile  which  it  contains.  This 
accumulation  of  the  blood  in  the  hepatic 
veins,  and  the  emptiness  of  the  portal 
plexus,  seem  due  to  the  continuance  of  ca- 
pillary action  after  the  general  circulation 
has  ceased;  a  circumstance  to  which  we 
find  an  exact  parallel,  in  the  emptiness  of 
the  systemic  arteries,  and  the  fulness  of  the 
veins,  after  most  kinds  of  death  (§  269).— 
In  the  second  stage  of  Hepatic  Venous 
congestion,  the  accumulation  of  blood  is 
found  not  only  in  the  intralobular  veins, 
but  even  in  parts  of  the  portal  or  lobular 

Venous  plexus.       The  parts  which  are  freest    Venom  congestion,  as  they  appear  on  the  sur- 
froin  it,  are  those  surrounding  the  interlo-  face  of  the  liver;  2,  interlobular  spaces  and 
bular  spaces;    so   that    the    non-congested  fissures, 
substance  here  appears  in  the  form  of  cir- 
cular or  irregular  patches,  in  the  midst  of  which  the  spaces  and  fissures  are  seen 
(Fig.  108). '     Although  the  portal  as  well  as  the  hepatic  venous  system  is  thus 
involved  in  this  form  of  congestion,  yet,  as  the  obstruction  evidently  originates 

1  This  very  common  aspect  of  the  Liver,  which  presents  numerous  modifications,  has 
oeen  a  source  of  great  perplexity  to  those  who  have  studied  the  minute  anatomy  of  this 
organ,  and  has  even  led  Anatomists  of  the  highest  eminence  into  serious  errors. — See  Mr 
Erasmus  Wilson,  in  "  Cyclop  of  Anat.  and  Physiol.,"  vol.  iii.  pp.  185,  186. 


FIG.  107. 


"2, 


1,  rounded  lobules  in  first  stage  of  Hepatic 


374 


OF  SECRETION  AND  EXCRETION. 


FIG.  108. 


in  the  latter,  the  term  given  by  Mr.  Kiernan  is  still  applicable  ;  and  it  is  impor- 
tant 10  distino-uish  this  appearance  from  that  next  to  be  described.     The  second 

stage  of  Hepatic  Venous  congestion  very 
commonly  attends  disease  of  the  heart,  and 
other  disorders  in  which  there  is  an  impe- 
diment to  the  venous  circulation  ;  and  in 
combination  with  accumulation  in  the 
biliary  ducts,  it  gives  rise  to  some  of  those 
appearances  which  are  known  under  the 
name  of  dram-drinkers'  or  nutmeg  liver. 
The  other  form  of  partial  congestion  arises 
from  an  accumulation  of  blood  in  the  por- 
tal veins,  with  a  reverse  condition  of  the 
hepatic  or  intralobular  veins  ;  in  this  con- 
dition, which  Mr.  K.  designates  as  Portal 
Venous  congestion,  the  marginal  portions 
of  the  lobules  are  of  deeper  colour  than 
usual,  and  form  a  continuous  network,  the 
isolated  spaces  between  which  are  occupied 
A,  lobules  in  the  second  stage  of  Hepatic  by  the  non-congested  portions  (Fig.  109). 
Venous  congestion,-  B,  and  c,  intralobular  ^njs  js  a  Very  rare  occurrence  j  having 
spaces;  D,  congested  intralobular  veins;  E,  been  ^^  ,  Mj.  R  in  chjldren  only._ 

«£t^^^  Th-  df  "  fully  explain  the  diver- 

tions  of  lobules.  si  ty  m  the  statements  or  the  older  anato- 

mists, as  to  the  relative  position  of  the  so- 

called  red  and  yellow  substances  ;  for  it  now  appears,  that  the  red  substance  is 
the  congested  portion  of  the  lobules,  which  may  be  either  interior,  or  exterior,  or 

irregularly-disposed  ;  whilst  the  yellow  is 
the  non-congested  part,  in  which  the  biliary 
plexus  shows  itself  more  or  less  dis- 
tinctly. 

396.  Another  very  interesting  form   of 
Pathological  change  in  the  aspect  of  the 
Liver,  which  the  knowledge  of  the  struc- 
ture of  the  lobules  enable  us  to  compre- 
hend,    is     that     l  granular-degeneration  ' 
which  is  very  apt  to  supervene  upon  In- 
flammatory affections  of  the  organ,  and  of 
which  one  form  has  been  known  as  Cir- 
rhosis.    The  liver  thus  affected  '   is  usu- 
ally diminished  in  bulk,   sometimes   con- 
siderably so  ;  it  is  harder  and  denser  than 
usual  'y  and   its  surface  is    roughened   by 
A,  lobules  as  they  appear  on  the  surface  in  the   projection   of    a  vast    number    of  mi- 
a  state  of  Portal  Venous  congestion;  B,  inter-  nute  bodies,  varying  in  size  from  that  of 
lobular  spaces   and   fissures;  c,  intralobular  ft     jn,g  head   to  that  of  a  hazel-nut,  whilst 
hepatic   veins,  containing  no   blood  :  D,  the  ,  ,  r  .  ,  .  L   •    i      •  mi. 

central  portions  in  a  state  of  anaemia;  E,  the  the    Connecting     tissue     shrinks-in.        The 


Fie.  109. 


n.arginal  portions  in  a  congested  state. 


whole  substance  of  the  viscus  is  altered 
in  the  same  manner.  When  the  bodies 
are  minute  and  closely-set,  they  impart  what  appears  at  first  to  be  a  uni- 
form brownish-yellow  tint  to  the  divided  surface;  but,  when  more  carefully  ex- 
amined, their  separation  becomes  evident,  their  own  hue  being  a  dullyellow,  like 

1  The  resemblance  which  the  cirrhosed  Liver  often  bears  to  the  sole  of  a  shoe  beset  with 
hob-nails,  has  occasioned  it  to  be  designated  'hob-nailed  liver;'  whilst,  from  the  cause  to 
which  the  various  forms  of  granular  degeneration  are  most  frequently  traceable  ;  the 
organ  thus  affected  is  often  described  as  'gin-liver.' 


THE     L1VEK. SECRETION       OF     BILE.  375 

unbleached  wax,  —  an  appearance  which  makes  it  not  surprising  that  Laennec 
should  have  been  led  to  regard  them  as  formed  by  a  new  deposit,  analogous  to 
that  of  tubercular  matter.  It  was  first  suggested  by  Cruveilhier,  that  the  yellow  ' 
bodies  really  consist  of  the  proper  substance  of  the  liver;  and  that  they  are 
formed  by  the  excessive  development  of  a  portion  of  the  lobules,  consequent  upon 
atrophy  of  the  remainder.  This,  however,  is  not  exactly  the  case  ;  for,  whether 
minute  granules  or  larger  bodies,  they  are  small  uncongested  patches,  composed 
of  parts  of  several  adjoining  lobules,  and  having  one  or  more  interlobular  spaces 
for  a  centre,  their  yellow  colour  being  simply  that  of  the  parenchyma  unusually 
charged  with  bile,  or,  at  least,  with  its  colouring  matter.  The  intervening  por 
tions  of  the  hepatic  substance  are  more  or  less  completely  atrophied  ;  and  the 
proper  parenchyma  is  partly  replaced  by  adventitious  fibrous  tissue,  which  inter- 
penetrates the  whole  mass  of  the  organ,  thus  imparting  to  it  greater  solidity  than 
usual. — The  mode  in  which  this  change  is  induced,  has  been  carefully  studied  by 
Dr.  G.  Budd;1  who  has  shown  that  it  begins  in  inflammatory  action,  either  acute 
or  chronic.  The  former  is  rare  in  this  country ;  but  a  form  of  the  latter,  termed 
by  Dr.  Gr.  Budd,  f  adhesive  inflammation  of  the  liver/  is  comparatively  frequent, 
especially  among  spirit-drinkers.  This  disease  seems  distinctly  traceable  to  the 
irritation  produced  in  the  organ,  and  especially  in  the  lining  membrane  of  its 
blood-vessels,  by  the  presence  of  alcohol  taken  into  the  circulating  current 
through  the  radicles  of  the  portal  vein ;  and  it  results  in  the  partial  or  complete 
obliteration  of  some  of  the  branches  of  that  trunk  which  carry  its  blood  through 
the  liver,  and  also  in  the  effusion  of  plastic  lymph  in  the  interlobular  spaces 
throughout  the  substance  of  the  viscus,  which  gradually  consolidates  into  a  fibrous 
tissue,  that  forms  thin  lines  between  small  irregular  masses  of  the  lobules,  and 
undergoes  a  gradual  contraction.  Both  these  causes  will  operate  to  produce  atro- 
phy of  a  considerable  part  of  the  parenchyma  of  the  liver,  and  a  drawing-in  of  its 
capsule  at  the  parts  corresponding  to  those  lines  of  fibrous  tissue;  whilst  the 
islets  that  still  receive  their  due  supply  of  nutriment,  become  hypertrophied,  and 
project  from  its  surface. 

397.  Among  the  most  frequent  of  the  pathological  changes  which  the  assist- 
ance of  the  Microscope  enables  us  to  discern  in  the  hepatic  cells,  is  that  engorge- 
ment with  adipose  particles,  which  is  observable  in 
the  condition  of  the  organ  known  as  ( fatty  liver'  FIG.  110. 

(Fig.  110).     This  state  having  been  frequently  ob- 
served in  individuals  who  have  died  of  phthisis  or 
other  diseases  of  the  lungs  involving  deficient  respi- 
ration, has  been  imputed  to  a  vicarious  action  of 
the  liver,  which  (as  was  supposed)  made  an   effort     n^atic  Cells  gorg^ih  Fat : 
thus  to  discharge  the  hydro-carbonaceous    matters  a,  atrophied  nucleus;  6,  adipose 
that  should  normally  be  eliminated  by  the  lungs,  globules. 
But  such  a  view  is  inconsistent  with  various  facts, 

which  show  (as  Mr.  Paget  has  justly  remarked)2  that  the  fatty  liver  is  an  inac- 
tive organ,  one  which  is  discharging  less  than  its  ordinary  function,  and  that  the 
accumulation  of  fat  in  its  cells  is  rather  to  be  considered  as  a  mark  of  *  fatty 
degeneration/  For  the  nuclei  disappear,  the  proper  colouring-matter  of  the  bile 
can  no  longer  be  distinguished,  the  liver  increases  in  size  owing  to  the  tardy  or 
obstructed  removal  of  its  cells,  and  its  paleness  indicates  a  slow  and  defective 
supply  of  blood;  moreover  the  fatty  liver  presents  itself  in  many  cases  in  which 
there  has  been  no  deficiency  of  respiration,  and  is  frequently  absent  in  phthisical 
subjects ;  and  there  is  no  evidence  whatever,  that  the  organ  when  in  this  state 
discharges  any  unusual  amount  of  fat  into  the  alimentary  canal.  Still  there  can 
be  little  doubt,  that  the  accumulation  of  adipose  matter  in  the  biliary  cells  is 
favoured  by  deficiency  of  respiration ;  for  a  marked  relation  of  reciprocity  is  div 

1  See  his  "  Treatise  on  Diseases  of  the  Liver,"  2nd  Edit. 

•  "  Lectures  on  Nutrition/  &c.  in  "Medical  Gazette,"  1847,  vol.  xl.,  p.  236. 


S76  OF    SECRETION    AND    EXCRETION. 

eernible  throughout  the  Animal  series,  between  the  amount  of  fat  contained  ii> 
the  Hepatic  apparatus,  and  the  activity  of  the  Respiratory  function ;  thus  in 
Birds,  the  biliary  cells  scarcely  contain  any  fatty  particles,  whilst  in  Reptiles  ana 
Fishes  they  are  loaded  with  them ;  and  nearly  the  same  difference  may  be  seen 
between  the  biliary  cells  of  Insects,  and  those  of  Crustacea  and  Mollusca.  This 
difference,  however,  is  probably  due  to  the  circumstance,  that  the  fat  which  it  is 
one  office  of  the  Liver  to  form  (§185),  is  at  once  carried-away  by  the  venous 
blood,  to  be  eliminated  by  the  lungs,  in  animals  whose  respiration  is  active ; 
whilst  it  remains  stored-up  in  the  parenchyma  of  the  organ,  in  those  whose  respi- 
ration is  comparatively  feeble. — Various  other  alterations,  however,  have  been 
noticed.  Dr.  T.  Williams  mentions,1  that,  in  a  case  of  obstruction  of  the  ductus 
choledochus  by  malignant  disease,  which  occasioned  complete  interruption  to  the 
passage  of  bile,  and  consequent  jaundice,  scarcely  an  entire  nucleated  cell  could 
be  discovered  by  attentive  examination  of  a  large  part  of  the  organ.  Nothing 
more  than  minute  free  particles  of  fat,  and  free  floating  amorphous  granular  mat- 
ter, could  be  detected.  He  further  states  that,  in  a  case  of  fever,  the  hepatic 
cells  were  found  to  be  almost  entirely  destitute  of  fatty  particles ;  and  that  in 
'  granular  liver/  the  cells  of  which  the  granules  consist,  strongly  resemble  the 
ordinary  cells  of  the  parenchyma  of  the  liver  in  every  respect,  except  that  they 
are  almost  or  completely  destitute  of  yellow  contents.  Similar  observations  have 
been  also  recorded  by  Dr.  G.  Budd.2 — In  two  cases  of  jaundice  examined  by  Mr. 
Gulliver,  the  hepatic  cells  were  gorged  with  biliary  matter,  some  of  them  to  such 
an  extent  that  they  had  become  nearly  opaque :  perhaps  if  this  condition  had 
continued,  these  cells  would  have  been  all  ruptured,  and  the  state  of  the  organ 
would  have  resembled  that  described  by  Dr.  Williams. 

398.  When  we  take  a  general  survey  of  the  structure  of  the  Liver  in  Man  and 
the  higher  Yertebrata,  and  of  the  relation  of  its  parenchymatous  tissue  to  the 
blood-vessels  on  the  one  hand  and  to  the  excretory  ducts  on  the  other, — and 
when  we  compare  these  arrangements  with  those  that  exist  in  the  Vascular 
Glands  and  in  the  ordinary  Secreting  Glands, — we  find  strong  reason  to  regard 
the  organ  as  sharing  in  the  structural  characters  of  both  those  classes  of  bodies, 
and  as  likely  to  perform  the  double  function  of  Assimilation  and  Secretion.  And 
this  inference  harmonizes  well  with  all  the  facts  which  have  been  ascertained 
with  regard  to  its  operation  on  the  blood.  For,  as  we  have  already  seen  (§132), 
there  is  very  clear  evidence,  that  the  Blood  in  circulating  through  the  liver  is  so 
changed  in  its  character,  as  to  be  rendered  more  fit  to  support  the  body;  and  this, 
not  only  by  the  removal  of  matters  whose  presence  would  be  noxious,  but  also  by 
a  conversion  or  higher  elaboration  of  those  which  are  destined  for  the  purposes  of 
nutrition.  Now  this  is  probably  the  special  purpose  of  the  parenchymatous  tis- 
sue, which  is  traversed  by  the  blood  in  its  passage  from  the  Portal  to  the  Hepatic 
Veins  j  just  as  the  parenchyma  of  the  Peyerian  and  Absorbent  Glandulse,  of  the 
Malpighian  bodies,  of  the  Spleen,  &c.,  is  traversed  by  blood  distributed  through 
their  capillary  plexuses  by  the  Systemic  Arteries.  On  the  other  hand,  the  biliary 
ducts  with  their  contained  cells,  which  are  supplied  by  the  Hepatic  Artery,  proba- 
bly constitute  (as  elsewhere)  the  proper  secreting  apparatus. — This  view  of  the 
double  character  and  function  of  the  Liver  in  Vertebrated  animals,  harmonizes 
well,  as  will  be  shown  hereafter  (Chap.  XVI.,  Sect.  4),  with  the  history  of  its  de- 
velopment; for  it  exists,  in  the  first  place,  as  a  parenchymatous  mass,  which  origi- 
nates independently  of  any  offset  from  the  Alimentary  Canal,  and  essentially 
resembles  those  masses  of  which  the  assimilating  glands  are  composed ;  a  diver- 
ticulum  of  the  intestine  extends  itself  towards  this,  and  gradually  pushes  its 
ramifications  into  its  substance ;  but  these  (as  we  have  seen)  never  proceed  further 
than  the  exterior  of  each  of  those  little  collections  of  parenchyma  that  forms  a 

•  "  Guy's  Hospital  Reports,"  1843. 

*  See  his  Treatise  on  "  Diseases  of  the  Liver,"  2nd  edit.,  pp.  211,  247,  &c. 


THE  LIVER. — SECRETION  OF  BILE.         377 

lobule.1 — Although,  however,  we  may  regard  the  converting  and  the  secreting 
actions  as  the  special  attributes  of  two  different  portions  of  the  apparatus,  there 
does  not  appear  to  be  adequate  reason  for  supposing  that  they  are  entirely  discon- 
nected, and  that  the  parenchymatous  substance  of  the  liver  takes  no  part  in  the 
secretion  of  bile.  On  the  contrary,  there  seems  every  probability,  from  the  inti- 
mate association  of  the  two  sets  of  actions  in  the  same  organ,  that  the  one  is  to  a 
certain  extent  the  complement  of  the  other  ]  biliary  matters  being  eliminated  in 
the  very  act  of  that  metamorphosis,  to  which  certain  components  of  the  blood  are 
subjected.  The  ordinary  absence  of  the  peculiar  biliary  compounds  from  the  con- 
tents of  the  hepatic  cells,2  is  no  objection  to  this  view ;  since,  if  this  matter  be 
transmitted  from  cell  to  cell,  towards  the  periphery  of  the  lobule,  as  fast  as  it  is 
formed,  we  should  no  more  expect  to  find  it  in  the  parenchyma,  than  we  expect 
to  find  any  quantity  of  urea  in  the  blood  when  the  kidneys  are  duly  performing 
their  function.  On  the  other  hand,  that  the  cells  of  the  hepatic  parenchyma  are 
occasionally  found  to  be  turgid  with  biliary  matter,  when  the  final  eliminating 
process  is  in  some  way  interfered-with,  seems  to  indicate  that  they  are  concerned 
in  its  separation  from  the  blood ;  although  this  action  may  be  altogether  subordi- 
nate to  the  converting  influence  which  they  exercise  upon  the  blood  itself. 

399.  Bile  is  a  viscid,  somewhat  oily-looking  liquid,  of  a  greenish-yellow  colour, 
and  very  bitter  taste,  followed  by  a  sweetish  after-taste.  It  is  readily  miscible 
with  water,  and  its  solution  froths  like  one  of  soap.  The  proportion  of  solid 
matter  which  it  contains,  is  usually  from  9  to  12  per-cent. ;  and  nearly  the  whole 
of  this  consists  of  substances  peculiar  to  Bile. — The  following  are  the  general  re- 
sults of  the  analyses  made  by  Berzelius,  of  Human  Bile,  and  of  that  of  the  Ox  : — 

MAN.  Ox. 

Water 9044  92-84 

Biliary  matter 8-00  5-00 

Mucus  of  the  gall-bladder -30  -23 

Soda -41 

Chloride  of  sodium,  and  extractive -74  1-50 

Phosphates  and  sulphates  of  soda  and  lime -11  43 


100-00          100-00 

In  the  Biliary  matter,  according  to  the  researches  of  Strecker  (which  are  un- 
doubtedly the  most  accurate  and  satisfactory  that  have  been  hitherto  made),  the 
following  substances  may  be  distinguished  : — Two  resinous  acids,  the  Glycocholic 
(which  is  the  cliolic  of  Strecker  and  many  former  authors)  and  the  Taurocholic 
(which  is  the  choleic  acid  of  Strecker,  and  is  nearly  the  same  with  the  bilin  of 
other  chemists) ;  these  are  formed,  according  to  Lehmann,  by  the  l  conjugation1 
of  Cholic  acid  with  glycine  (gelatine  sugar)  and  taurine  respectively ;  and  they 
are  united  in  the  bile  with  soda  as  a  base.  It  is  in  the  tauro-cholic  acid  that  the 
sulphur  of  the  bile  presents  itself,  no  less  than  25  per  cent,  of  that  element  ex- 
isting in  taurine ;  so  that  the  proportion  which 
this  acid  bears  to  the  glycocholic  (which  differs 
greatly  in  different  animals)  may  be  estimated 
by  the  amount  of  sulphur  in  the  mixture  of  the 
two.  Besides  a  variable  quantity  of  the  ordi- 
nary Fatty  acids,  Bile  also  contains  Choleste- 
rin,  (Fig.  Ill),  a  non-saponifiable  crystalline 
fatty  substance;  and  also  a  peculiar  pigment 
very  rich  in  carbon,  and  apparently  related  to 
the  colouring  matter  of  the  blood),  which 
forms,  in  combination  with  lime,  the  insoluble 
granular  matter  that  may  be  distinguished  in  Cholesterin.] 

1  See  Huxley  in  "  Quart.  Journ.  of  Microsc.  Science,"  vol.  ii.  p.  82. 

2  See  the  evidence  of  this,  adduced  by  Dr.  C.  Handfield  Jones,  in  "  Phil.  Trans.,"  1853. 


378  OF    SECRETION    A  N  I>     EXCRETION. 

bile  by  microscopic  examination.  —  It  is  remarkable  that,  notwithstanding  the 
comparatively-minute  proportion  in  which  these  two  last  substances  exist  in  ordi- 
nary bile,  cholesterin  should  usually  be  the  principal  ingredient  of  the  biliary 
concretions  which  are  frequently  found  in  the  gall-bladder  and  bile-ducts;  and 
that  the  bile-pigment  with  its  calcareous  base  should  also  occasionally  accumu- 
late, so  as  to  form  solid  masses  which  consist  of  little  else.  It  would  appear 
from  this,  that  the  peculiar  resinous  acids  of  the  bile  are  far  more  readily  re-ab- 
sorbed, than  are  its  other  ingredients ;  and  this  corresponds  with  the  results  of 
experiments  upon  the  contents  of  the  alimentary  canal,  which  show  that  whilst 
the  colour  of  the  faeces  is  chiefly  due  to  the  presence  of  bile-pigment,  the  conju- 
gated acids  are  scarcely  to  be  recognized  in  them. 

400.  The  quantity  of  Bile  ordinarily  secreted  by  the  liver,  the  circumstances 
which  favour  or  retard  its  production,  the  mode  in  which  it  is  discharged  into  the 
intestine,  and  the  purposes  which  it  answers  in  the  Digestive  process,  having  all 
been  considered  under  a  previous  head  (§§  110 — 112),  we  have  now  to  enquire 
into  the  conditions  under  which  the  Secretion  takes  place ;  and  one  of  the  most 
important  of  these,  is  the  supply  of  Blood  which  the  Liver  receives.  How  far 
the  blood  supplied  by  the  Hepatic  Artery  is  the  immediate  source  of  the  secre- 
tion, cannot  be  positively  ascertained ;  there  is  no  doubt,  however,  that  it  may 
become  so  indirectly,  by  finding  its  way  into  the  portal  system.  For,  if  the 
Vena  Portse  be  tied,  the  secretion  of  bile  still  continues,  though  in  diminished 
quantity ;  and  several  cases  are  on  record,  in  which,  through  a  malformation,  the 
vena  portse  terminated  in  the  vena  cava  without  ramifying  through  the  liver,  and 
in  which  secretion  of  bile  took  place, — evidently  from  the  blood  of  the  hepatic 
artery,  which  appeared  to  have  passed  into  the  ramifications  of  the  umbilical  vein, 
these  forming  a  plexus  in  the  lobules,  that  exactly  resembled  the  ordinary  portal 
plexus.1 — What  effect  the  interruption  of  the  supply  of  blood  by  the  Hepatic 
Artery  would  have  upon  the  amount  of  bile,  has  not  yet  been  experimentally  de- 
termined ;  but  as  its  area  is  not  more  than  one-eighth  that  of  the  Portal  vein, 
and  as  the  great  diminution  of  the  secretion  when  the  latter  is  tied  shows  that  its 
blood  furnishes  the  chief  part  of  the  materials  of  the  bile,  it  may  be  fairly  consi- 
dered that  the  supply  of  blood  by  the  Hepatic  Artery  is  by  no  means  essential  to 
the  act  of  secretion,  although  it  may  well  be  to  the  nutrition  of  the  organ.  The 
case  of  the  Lungs,  which  are  supplied  with  arterial  blood  by  the  bronchial  vessels, 
as  well  as  with  venous  blood  by  the  proper  pulmonary  trunks,  seems  on  the 
whole  analogous;  the  chief  p  ints  of  difference  being,  that  the  bronchial  arteries 
have  corresponding  veins  of  their  own,  instead  of  discharging  their  blood  into  the 
pulmonary  current. — The  fact  that  the  secretion  of  Bile  is  thus  normally  formed, 
in  great  part  at  least,  from  venous  blood,  has  been  commonly  connected  with  the 
hydrocarbonaceous  nature  of  its  chief  components,  which  must  exist  (it  is  con- 
sidered) in  larger  proportion  in  such  blood  than  in  that  of  the  arteries.  But  it 
must  be  borne  in  mind,  that  the  urinary  excretion,  which  is  undoubtedly  formed 
at  the  expense  of  the  products  of  the  disintegration  of  the  tissues,  is  secreted  from 
arterial  blood ;  and  since  the  bile  is,  as  it  were,  the  complement  of  the  urine  (the 
ultimate  components  of  the  two  together  making-up  the  composition  of  blood2), 

1  This,  at  least,  was  found  to  be  the  case,  in  the  only  instance  in  which  the  Liver  was 
examined  with  sufficient  care.  See  Kiernan,  loc.  cit. 

5  It  has  been  pointed-out  by  Prof.  Liebig,  that  if  we  add  to  half  the  formula  represent- 
ing the  ultimate  composition  of  bile,  the  formula  of  urate  of  ammonia  (which  is  the  charac- 
teristic component  of  the  urine  of  all  animals  save  Mammalia),  the  sum  gives  the  propor- 
tionals of  the  ultimate  components  of  dried  blood  or  of  flesh,  with  the  addition  of  1  equiv. 
of  oxygen  and  1  equiv.  of  water.  For : — 

£  Equiv.  of  Biliary  matter=r38C,  33H,    N,  110 
1  Equiv.  of  Urate  of  Ammonia=10C,     7H,  5N,     60 


The  Sum  of  which=48C,  40H,  6N,  170 


THE     LIVER.  —  SECRETION     OF    BILE.  37P 

there  seems  no  reason  why  arterial  blood  should  not  furnish  its  materials,  as 
abundantly  (or  nearly  so)  as  venous.  The  real  explanation  of  the  peculiar  rela- 
tion of  the  Liver  to  the  Venous  circulation,  is  probably  to  be  found  in  the  action 
of  the  organ  upon  the  matters  newly-absorbed  into  the  circulation  from  the  ali- 
mentary canal.  That  this  action  is  not  only  assimilative,  as  already  shown  (§132), 
but  is  also  to  a  certain  extent  depurative,  appears  from  the  fact  that  the  liver 
tends  to  remove  from  the  blood,  and  to  store-up  in  its  own  substance,  certain 
foreign  matters  of  an  injurious  kind, — such  as  copper  and  arsenic, — which  have 
found  their  way  into  the  tributaries  of  the  portal  system.  This  seems  also  to  be 
the  case  with  respect  to  pus,  which,  when  taken-up  from  ulcers  in  the  intestinal 
walls,  is  stopped  in  the  liver,  and  not  unfrequently  gives  rise  to  abscesses  in  its 
substance.1 

401.  How  far  the  constituents  of  the  Bile  are  preformed  in  tlie  Bloafl,  or  to 
what  extent  they  are  elaborated  by  the  Liver,  is  not  yet  certainly  determined. 
It  might  be  expected,  that  if,  like  the  components  of  the  urinary  secretion,  they 
pre-exist  in  the  circulating  current,  and  are  merely  eliminated  from  it  by  the 
agency  of  the  Liver,  they  would  accumulate  in  it  when  that  elimination  is  checked 
by  the  removal  of  the  secreting  organ  ;  yet  M  tiller,  Kunde,  Lehmann,  and  Moles- 
chott  have  carefully  examined  the  blood  of  frogs  thus  treated,  without  finding 
any  traces  either  of  the  peculiar  resinous  acids,  or  of  the  colouring-matters  of 
bile.2  —  Even  though  the  materials  of  the  biliary  secretion,  however,  should 
receive  their  complete  and  characteristic  form  in  the  liver  itself,  it  is  not  less 
certain  that  they  are  produced  at  the  expense  of  substances  of  an  excrementi- 
tious  character,  whose  retention  in  the  circulating  current  would  be  injurious ; 
this  being  strikingly  demonstrated  by  the  disturbance  of  the  functions  generally, 
and  especially  of  those  of  the  Nervous  system,  which  is  consequent  upon  the 
suspension  of  the  secreting  process.  When  the  suppression  is  complete,  the 
powers  of  that  system  are  speedily  lowered  (almost  as  by  a  narcotic  poison),  the 
patient  suddenly  becomes  jaundiced,  and  death  rapidly  supervenes.3  When  the 
secretion  is  diminished,  but  not  suspended,  the  same  symptoms  present  them- 
selves in  a  less  aggravated  form.  It  is  probable  that  much  of  the  disorder  in 
the  functions  of  the  brain,  which  so  constantly  accompanies  deranged  action  of  the 
digestive  system,  is  due  to  the  less  severe  operation  of  the  same  cause ;  namely, 

And  in  like  manner 

Formula  of  Blood=48C,  39H,  6N,  150 
1  Equiv.  of  Water -}-l  Equiv.  of  Oxygen=r  H,  20 

48C,  40H,  6N,  170 

Although  these  formulae  can  by  np  means  be  supposed  to  represent  the  process  >vhich  ac- 
tually takes  place,  yet  the  coincidence  is  so  close,  as  to  indicate  that  the  complementary 
relation  spoken-of  above  has  a  real  existence. 

1  See  Dr.  G.  Budd's  "Treatise  on  Diseases  of  the  Liver,"  2nd  edit.,  Chap,  ii.,  sect.  1. 

2  See  the  second  edition  of  Prof.  Lehmann's  "  Physiologischen  Chemie,"  band  ii.  pp. 
75,  76.  —  It  has  been  already  stated,  however,  that  Enderlin  affirms  cholic  acid  to  be  a 
normal  ingredient  of  the  blood  (%  172  note) ;  so  that  the  matter  must  be  regarded  as  still 
undetermined. 

3  See  Prof.  Alison  in  "Edinb.   Med.  and  Surg.  Journ.,"  vol.  xliv;  and  Dr.  Budd,  Op. 
Cit.,  Chap.  iii.  —  From  the  evidence  collected  by  Dr.  Budd,  he  is  led  to  think  it  probable 
that  the  cerebral  symptoms  are  not  due  to  the  simple  retention  of  the  materials  of  Bile ; 
but  depend  upon  some  metamorphosis  which  these  undergo  whilst  circulating  with  the 
blood,  whereby  a  more  noxious  poison  is  generated.     For  the  general  symptoms  of  sup- 
pression of  the  secretion  may  have  shown  themselves  for  some  time,  before  any  serious 
disturbance  occurs  in  the  cerebral  functions ;  and  this  may  supervene  very  suddenly,  and 
be  fatal  in  a  few  hours  (p.  263).     The  analogy  of  Unemia  ($  409)  seems  to  afford  some 
confirmation  to  this  view ;  but  it  must  be  borne  in  mind  as  a  possible  explanation  of  the 
phenomena,  and   one  which  has   evidence  in  its  favour,  that  the  kidneys,  by  a  vicarious 
action,  remove  the  most  poisonous  of  the  retained  biliary  matters  ;  and  that  it  is  onlj  when 
they  can  no  longer  effect  this,  that  the  results  of  the  accumulation  of  these  matters  begin 
to  snow  themselves  in  the  perversion  of  the  functions  of  the  nervous  centres. 


380  OF    SECRETION    AND    EXCRETION. 

the  partial  retention  within  the  blood,  of  certain  constituents  of  the  bile,  which 
should  have  been  eliminated  from  the  circulating  fluid.  Such  an  abnormal  accu- 
mulation, which  may  depend  either  on  a  deficiency  in  the  functional  activity  of 
the  liver,  or  on  an  excess  of  the  excrementitious  matters  brought  to  it  for  elimi- 
nation, is  habitual  in  some  persons;  and  it  produces  a  degree  of  indisposition  to 
bodily  or  mental  exertion,  which  is  difficult  to  counteract.  More,  probably,  is  to 
be  gained  in  such  cases  by  the  regulation  of  the  diet,  especially  the  reduction  of 
its  hydro-carbonaceous  components,  and  by  active  exercise  (which,  by  augment- 
ing the  respiration,  will  promote  the  elimination  of  any  superfluity  of  this  kind 
through  the  lungs),  than  by  continually  inciting  the  liver  to  increased  functional 
activity,  by  medicines  which  have  a  special  power  of  temporarily  augmenting  its 
energy.  —  The  excrementitious  character  of  the  Biliary  secretion  is  very  strik- 
ingly indicated  by  its  formation  during  the  foetal  life;1  which,  as  it  can  then 
have  reference  neither  to  the  function  of  Digestion  nor  to  that  of  Respiration, 
must  be  regarded  as  having  for  its  purpose  to  free  the  blood  of  matter  which 
would  be  injurious  to  it.  And  this  matter  can  hardly  arise  from  any  other  source, 
than  the  *  waste'  of  the  tissues  (consequent  upon  the  limited  duration  of  their 
existence),  which  takes  place  even  when  the  life  of  the  organism  is  most  purely 
vegetative.  The  re-absorption  of  Bile  into  the  blood,  as  seen  in  ordinary  cases 
of  jaundice  dependent  upon  the  obstruction  of  the  biliary  ducts,  does  not  act  on 
the  general  system  in  a  manner  nearly  so  injurious,  as  the  retention  of  the  mat- 
ters at  the  expense  of  which  it  is  formed  has  been  shown  to  do  ;2  in  fact,  much 
of  the  disturbance  which  then  ensues,  may  be  attributed  to  the  disorder  of  the 
digestive  function,  which  is  consequent  upon  the  stoppage  of  the  flow  of  bile  into 
the  intestinal  canal  (§§  111,  112).  And  when  it  is  further  remembered,  that 
the  greater  part  of  the  bile  which  passes  into  the  intestinal  canal  is  ordinarily 
destined  for  re-absorption  (§  117),  it  seems  fair  to  conclude,  that  the  matters 
which  accumulate  in  the  blood  when  the  secreting  action  of  the  liver  is  sus- 
pended, are  not  in  the  same  condition  with  those  which  are  received-back  into  it 
after  being  submitted  to  that  action ;  and  that  the  liver,  therefore,  not  merely 
separates  them,  but  exercises  a  certain  transforming  agency  upon  them. 

402.  From  what  components  of  the  Blood  the  materials  of  the  biliary  secre- 
tion are  immediately  derived,  is  a  question  that  cannot  yet  be  answered  with  more 
certainty  than  the  preceding.  The  close  resemblance  in  composition,  between 
the  resinous  acids  of  bile,  and  the  ordinary  fats  (especially  olein),  naturally  sug- 
gests the  idea  that  they  are  drawn  from  the  fatty  matters  of  the  blood ;  but  to 
this  notion  there  are  many  serious  objections,  both  physiological  and  chemical. 
One  of  the  most  important  of  these  is  the  fact  ascertained  by  MM.  Bidder  and 
Schmidt,  that  the  flow  of  bile  is  not  increased  by, a  predominance  of  fat  in  the 
food,  and  that  animals  fed  exclusively  on  fat  do  not  secrete  more  bile  than  those 
entirely  deprived  of  food :  whilst  it  has  been  found  by  Nasse,  that  the  presence 
of  a  large  amount  of  protein-compounds  in  the  food  occasions  a  great  augumen- 
tation  in  this  secretion.3  The  increase  of  the  secretion  after  each  ordinary  inges- 
tion  of  food  (§  112),  and  its  marked  and  progressive  diminution  in  animals 
entirely  deprived  of  aliment  (as  determined  by  MM.  Bidder  and  Schmidt),  seem 

1  It  has  been  shown  by  Simon  and  Frerichs,  that  the  meconium  which  is  contained  in  the 
intestinal  canal  at  birth,  is  chiefly  composed  of  accumulated  bile. 

3  Dr.  Budd  mentions  several  cases  (Op.  cit.  pp.  209-227),  in  which  the  passage  of  bile 
into  the  intestines  was  entirely  prevented  by  the  complete  closure  of  the  ductus  communis, 
and  in  which,  nevertheless,  life  was  prolonged  for  many  months ;  in  one  of  them,  the 
jaundice  first  occurred  in  a  woman  four  months  pregnant,  who  nevertheless  bore  a  living 
child  at  the  full  period,  and  suckled  it  up  to  the  time  of  her  death,  which  happened  when 
the  child  was  three  months  old.  —  In  all  these  cases,  death  seemed  to  result  from  gradual 
exhaustion,  consequent  upon  the  imperfect  assimilation  of  food,  rather  than  from  any  toxic 
agency ;  and  this  even  when  the  liver  was  in  such  a  state  of  disorganization,  that  its  func- 
tional activity  must  have  been  suspended  for  some  time  before  death. 

*See  Prof  Lehmann's  "  Physiologischen  Chemie,"  2nd  edit.,  band  ii.,  pp.  64-66. 


THE    KIDNEYS  : — S  ECRETION    OF    URINE.  381 

to  indicate  that  its  materials  may  be  directly  derived  in  part  from  proteinaceous 
materials  which,  do  not  undergo  metamorphosis  into  tissue ;  whilst  on  the  other 
hand,  there  is  every  reason  to  believe,  that  the  production  of  the  components  of 
bile  is  a  necessary  part  of  those  processes  of  retrograde  metamorphosis,  by  which 
the  materials  of  the  effete  tissues  are  removed  from  the  system.  —  But  it  is  not 
the  formation  of  bile  alone,  that  is  effected  by  the  Liver  at  the  expense  of  these 
substances;  for  the  experiments  of  M.  (11.  Bernard1  have  clearly  proved,  that 
the  peculiar  sugar  which  is  found  in  the  blood  of  the  hepatic  vein,  and  which 
may  be  extracted  also  from  the  substance  of  the  liver  itself,  may  be  generated  at 
the  expense  of  protein-compounds;  and  the  same  is  probably  the  case  with  the 
liver-fat j  the  production  of  which  seems  to  be  in  great  degree  vicarious  with  that 
of  sugar.  Now  these  substances  are  not  less  truly  products  of  secretion,  than  is 
the  bile  itself;  although  they  are  carried-off  by  the  blood  of  the  hepatic  vein, 
and  are  directly  eliminated  by  the  lungs,  instead  of  being  withdrawn  from  the 
current  of  the  circulation,  and  discharged  through  the  biliary  ducts  into  the 
alimentary  canal. — Taking  all  these  considerations  into  account,  we  seem  entitled 
to  conclude,  that  besides  its  operation  as  an  Assimilating  organ,  whereby  it  helps 
to  prepare  histogenetic  materials  for  conversion  into  blood  and  solid  tissue,  the 
Liver  exerts  its  Secretive  action,  in  separating  the  hydrocarbonaceous  portion  of 
the  protein-compounds  which  are  destined  to  undergo  retrograde  metamorphosis, 
as  being  either  superfluous  or  effete;  and  this  under  the  three  forms  of  Sugar, 
Fat,  and  Bile.  The  two  former,  if  not  at  once  removed  by  the  blood-current, 
remain  stored-up  in  the  liver  itself,  as  a  pabulum  for  respiration ;  the  latter, 
being  of  use  in  the  digestive  operation,  is  first  poured  into  the  alimentary  canal, 
from  which,  however,  the  greater  part  is  subsequently  reabsorbed,  its  components 
being  oxidated  and  then  eliminated  through  other  channels,  the  Hydro-Carbon 
as  water  and  carbonic  acid  through  the  Lungs,  the  Sulphur  as  sulphuric  acid 
through  the  Kidneys. 

403.  Not  only  in  thus  helping  to  decompose  the  protein-compounds,  and  to 
eliminate  from  them  the  appropriate  materials  for  the  combustive  process  (so  that  the 
immediate  pabulum  of  that  process  is  the  same  in  Carnivorous,  as  in  Herbivorous 
animals),  is  the  Liver  subservient  to  the  Respiratory  function.     For  it  converts 
all  forms  of  saccharine  matter  derived  from  the  food  into  '  liver-sugar/  the  form 
which  is  most  favourable  to  oxidation ;  and  it  exercises  a  similar  transforming 
power  upon  fatty  matter,  generating  the  peculiar  l  liver-fat/  from  other  oleagi- 
nous or  from  saccharine  substances   supplied  by  the   food.     It  is  not,  then,  so 
much  by  the  separation  of  bile  (as  formerly  propounded  by  Prof.  Liebig),  as  by 
the  change  which  it  effects  in  the  circulating  blood,  that  the  Liver  prepares  the 
materials  adapted  for  the  sustenance   of  the  combustive   operation.     For  it  is 
quite  certain,  that  if  the  whole  of  the  solid  biliary  matter  poured  into  the  intes- 
tine were  re-absorbed,  it  could  furnish  but  a  small  proportion  (probably  not  more 
than  one-twelfth)  of  the  total  amount  of  hydrocarbon  which  is  eliminated  by  the 
lungs :  and  the  preparation  of  the  liver-sugar  and  liver-fat  in  the  blood  itself,  is 
evidently  the  far  more  important  part  of  the  office  of  the  Liver,  as  regards  the 
Respiratory  function. 

3.    The  Kidneys. — Secretion  of  Urine. 

404.  The  Kidneys  cannot  be  regarded  as  inferior  in  importance  to  the  Liver, 
when  considered  merely  as  Excreting  organs ;  but  their  function  only  consists  in 
separating  from  the  blood  certain  effete  substances  which  are  to  be  throwa-off 
from  it,  and  has  no  direct  connection  with  any  of  the  nutritive  operations  con- 
cerned in  the  introduction  of  aliment  into  the  system.     The  following  are  tho 
points  in  the  minute  structure  of  these  organs,  which  are  of  most  importance  in 
their  Physiological  relations.2     Their  glandular  and  vascular  elements  are  im- 

1  "Nouvelle  Fonction  du  Foie,"  (1853),  chap.  ii. 

2  See  especially  Mr.  Bowman's  Memoir  in  the  "Philosophical    Transactions;"  18-12; 
also  Goodsir  in  "  Edinb.    Monthly  Journal,"   1842 ;    Gerlach,   Bidder,   and  Kolliker,  in 


382 


OF  SECRETION  AND  EXCRETION. 


bedded  in  a  stroma  composed  of  interlacing  fibres  (Fig.  112,  c?cT);  this  is  more 
abundant  in  the  medullary,  than  in  the  cortical  substance;  but  at  the  surface  of 
the  gland  it  is  condensed  into  a  continuous  membrane,  which  is  loosely  connected 


FIG.  112. 


Section  of  the  Cortical  Substance  of  the  Human  Kidney  : — A  A,  tubuli  uriniferi  divided  trans- 
versely, showing  the  spheroidal  epithelium  in  their  interior ;  B,  Malpighian  Cnpsule  :  a,  its  afferent 
branch  of  the  renal  artery ;  6,  its  glomerulus  of  capillaries ;  c  c,  secreting  plexus,  formed  by  its 
efferent  vessels ;  d  d,  fibrous  stroma. 

with  the  proper  capsule.  The  distinction  between  the  cortical  and  the  medullary 
part  of  the  Kidney  essentially  consists  in  this,  —  that  the  former  is  by  far  the 
most  vascular,  and  the  plexus  formed  by  the  tubuli  uriniferi  seems  to  come  into 
the  closest  relation  with  that  of  the  sanguiferous  capillaries,  so  that  it  is  pro- 


FIG.  114. 


Fie.  113.  A  portion  of  the  Kidney  of  a  new-born  infant:  —  A,  natural  size:  1,  1,  Corpora 
Malpighiana,  as  dispersed  points  in  the  cortical  substance ;  2,  papilla. — B,  a  smaller  part  mag- 
nified ;  1,  1,  Corpora  Malpighiana ;  2,  tubuli  uriniferi. 

FIG.  114.  Portion  of  one  of  the  tubuli  uriniferi,  from  the  Medullary  substance  of  the  kid- 
ney of  an  adult;  showing  its  tesselated  epithelium. 

bably  the  seat  of  the  greater  part  of  the  process  of  secretion ;  whilst  the  latter 
is  principally  composed  of  tubes,  passing  in  a  straight  line  from  the  former 
towards  their  point  of  entrance  into  the  ureter.  The  tubuli  uriniferi,  in  passing 

"Mullers's  Archiv.,"  1845  ;  Toynbeein  «•  Med.-Chir.  Trans.,"  1846:  Johnson  in  "Cyclop. 
of  Anat.  and  Phys.,"  art.  '  Ren.';  Gairdnerin  "  Edinb.  Monthly  Journal,''  1848;  Frerichs, 
"  Die  Bright'sche  Nierenkrarikheit  und  deren  Behandlung,"  1851 ;  and  Kolliker,  "Mikro- 
"kopische  Anatomic,"  and  "Man.  of  Hum.  Histol."  (Syden.  Soc.) 


THE  KIDNEYS.  — SECRETION  OF  URINE. 


383 


outwards  from  the  calices, 
increase  in  number  by  di- 
varication to  a  considerable 
extent,  as  shown  in  Fig. 
115,  but  their  diameter 
remains  the  same.  When 
they  arrive  in  the  cortical 
substance,  their  previously- 
straight  direction  is  de- 
parted-from,  and  they  be- 
come much  convoluted. 
The  closeness  of  the  tex- 
ture formed  by  their  in- 
terlacement with  the  blood- 
vessels, renders  it  difficult 
to  obtain  a  clear  view  of 
their  mode  of  termination  ; 
but  they  seem  to  inosculate 
with  each  other,  so  as  to 
form  a  plexus,  with  free 
extremities  here  and  there 
(Fig.  115);  the  number 
of  such  free  extremities, 
however,  does  not  appear 
to  be  nearly  equal  to  that 
of  the  uriniferous  tubes 
themselves.1  The  tubuli 
are  lined  with  an  epithe- 
lium, the  character  of 
which  varies  in  different 
parts  of  their  course.  In 
the  tubes  of  the  cortical 
substance,  the  cells  are 
spheroidal  in  their  form, 
and  project  considerably 
from  the  basement  mem- 
brane on  which  they  lie, 
so  as  to  occupy  a  consider- 
able part  of  the  area  (Fig. 
112,  A  A),  as  is  the  case 
with  those  of  glandular 
follicles  generally.  In  the 
straight  tubes  of  the  me- 
dullary substance,  on  the 
other  hand,  the  cells  are 
flattened  and  polygonal, 
corresponding  to  the  gene- 
ral type  of  pavement-epi- 
thelium (Fig.  114);  and 
they  project  so  little  from 
the  walls  of  the  tube,  as  to 


A  small  portion  of  the  Kidney,  magnified  about  60 
— 1,  supposed  caecal  extremity  of  a  tubulus  uriniferus ;  2,  2, 
recurrent  loops  of  tubuli;  3,  3,  bifurcations  of  tubuli;  4,  5,  6, 
tubuli  converging  towards  the  papilla;  7,  7,  7,  Corpora  Mai- 
pighiaua,  seen  to  consist  of  convoluted  knots  of  blood-vessels, 
connected  with  a  capillary  net-work  ;  8,  arterial  trunk. 


occasion  but  little  diminution   in  its  area.     Each  cell  contains  a  nucleus ;  and 

1  In  Mr.  Bowman's  opinion,  all  the  free  extremities  of  the  tubuli  uriniferi  include  Cor- 
pora Malpighia-na  ;  and  the  appearance  of  csecnl  terminations,  such  as  those  represented 
at  2  and  3,  Fig.  115,  he  regards  as  an  optical  illusion,  caused  by  a  change  in  the  direction 
of  the  tubuli,  which  occasions  them  to  dip-away  suddenly  from  the  observer. 


384 


OP  SECRETION  AND  EXCRETION. 


116. 


hi  its  interior  there  is  ordinarily  to  be  seen  a  little  finely-granular  matter, 
with  a  few  minute  fat-globules  clustered  round  the  nucleus;  the  cell- 
wall  is  remarkable  for  its  delicacy,  and  is  one  of  the  first  structures  to  undergo 
decomposition  ;  and  after  its  destruction,  free  nuclei,  interspersed  among  amor- 
phous granules,  alone  remain  in  the  interior  of  the 
tubules.  Scattered  through  the  plexus  formed  by  the 
blood-vessels  and  uriniferous  tubes,  a  number  of  little 
dark  points  may  be  seen  with  the  naked  eye,  to  which 
the  designation  of  Corpora  Malpighiana  has  been 
given,  after  the  name  of  their  discoverer.  Each  one 
of  these,  when  examined  with  a  high  magnifying 
power,  is  found  to  consist  of  a  convoluted  mass  of 
minute  blood-vessels  (Fig.  115,  7);  and  this  is  in- 
cluded in  a  flask-like  dilatation  of  one  of  the  tubuli 
uriniferi  (Figs.  112,  B,  116,  c,  c').  According  to  Mr. 
Bowman,  this  dilatation  proceeds  only  from  the  termi- 
nation of  the  tubulus;  and  this  seems  to  be  usually 
the  case,  although  it  appears  not  improbable  that  it 
may  sometimes  be  a  lateral  diverticulum,  as  described 
by  Gerlach  (loc.  cit.).  The  epithelium,  which  else- 
where lines  the  tube,  is  altered  in  appearance  where 
the  tube  is  continuous  with  this  capsular  dilatation 
(Fig.  116,  &');  being  there  more  transparent,  and  fur- 
nished with  cilia  (as  shown  at  &"),  which,  in  the  Frog 
and  other  Reptiles,  may  be  seen  for  many  hours  after 
death,  in  very  active  motion,  directing  a  current  down 

Uriniferous  Tube,  Malpighian  the  tube.  Further  within  the  capsule,  this  epithe- 
Tuft,  and  Capsule,  from  Kidney  Hum  becomes  excessively  delicate,  and  sometimes  dis- 
ofFr,,g:—a,  cavity  of  the  tube;  appearg  altogether.  The  surface  of  the  Malpighian 
o;1±h:p^,lthoV,hbee;eci  *>»  |f  often  seen  to  be  studded  with  nuclear  particles, 
of  the  capsule;  b",  detached  which  suggest  the  idea  that  it  is  covered  by  an  epi- 
epithelium-scale;  c,  basement-  thelial  layer;  and  hence  Grerlach,  followed  by  other 
membrane  of  tube;  c',  base-  anatomists,  has  maintained  that  the  flask-shaped  dila- 
ment-membrane  of  capsule;  toti(m  of  thfl  tubulus  uriniferus  is  not  perforated  by 

m,  convoluted  capillaries  01  the    ,,       ,  ,       ,  ,        i  •   i_   p          .1       T%T  i    •    i.  •        ±    c     -\ 

Malpighian  tuft.  tne  blood-vessels  which  lorrn  the  Malpighian  tuit,  but 

is  reflected  over  them.     It  appears  probable,  however, 

that  these  nuclear  particles  really  belong  to  the  walls  of  the  vessels  ;  and  the 
most  careful  examination  has  failed  to  detect  any  such  reflection.  On  this  as  on 
all  other  points  of  importance,  therefore,  Mr.  Bowman's  original  description 
proves  to  be  unassailable/ 

•  405.  The  Circulation  of  Blood  through  the  Kidney  presents  a  very  remark- 
able peculiarity.  The  supply  is  derived  in  Man  (as  in  other  Mammalia)  direct 
from  the  arterial  system  ;  though  in  Fishes  and  Reptiles  the  urinary  apparatus 
is  connected,  as  well  as  the  biliary,  with  the  portal  venous  system,  and  even  in 
Birds  a  portion  of  its  blood  is  derived  from  the  latter.  But  although  this  organ 
is  supplied  from  the  Renal  Artery,  yet  it  is  not  to  its  proper  secretory  apparatus 
that  the  blood  of  the  artery  is  distributed  in  the  first  instance  ;  for,  on  entering 
the  kidney,  this  vessel  speedily  and  entirely  divides  itself  into  minute  twigs, 
which  are  the  afferent  vessels  of  the  Malpighian  tufts  (Figs.  112,  a,  117,  of) 
After  it  has  pierced  the  capsule,  each  twig  dilates  ;  and  suddenly  divides  and  sub- 
divides itself  into  several  minute  branches,  terminating  in  convoluted  capillaries, 
which  are  collected  in  the  form  of  a  ball  (Figs.  112,  b,  117,  m,  w-);  and  from  the 

1  Tne  d  priori  improbability  that  the  basement-membrane  of  a  glandular  tubule  or  fol- 
licle should  be  thus  penetrated  by  blood-vessels,  has  been  entirely  removed  by  the  discovery 
that  such  penetration  does  take  place  in  other  cases,  as  the  Peyerian  glandulge  ($  133)  and 
the  Corpora  Malpighiana  of  the  Spleen  (§  142  n). 


THE    KIDNEYS.  —  SECRETION    OF    URINE.  385 

interior  of  the  ball,  the  solitary  efferent  vessel,  ef,  arises,  which  passes  out  of 
the  capsule  by  the  side  of  the  single  afferent  vessel.     This 
ball  seems  to  lie  loose  and  bare  in  the  capsule,  being  at-  Fro.  117. 

tached  to  it  only  by  its  afferent  and  efferent  vessels  (Fig. 
112,  6).  The  efferent  vessels,  on  leaving  the  Malpighian 
bodies,  separately  enter  the  plexus  of  capillaries  (Figs. 
112,  c,  117,  p),  surrounding  the  tubuli  uriniferi  (sZ),  and 
supply  that  plexus  with  blood;  from  this  plexus  the  renal 
vein  arises. — Thus  there  is  a  striking  analogy  between  the 
mode  in  which  the  tubuli  uriniferi  are  supplied  with  blood, 
for  the  purpose  of  elaborating  their  secretion,  and  the  plan 
on  which  the  hepatic  circulation  is  carried-on.  For  as  the 
secretion  of  the  Liver  is  formed  from  blood  conveyed  to  it 
by  one  large  vessel,  the  portal  vein,  which  has  collected  it 
from  the  venous  capillaries  of  the  chylopoietic  viscera,  and 
which  subdivides  again  to  distribute  it  through  the  liver,  so 
the  secretion  of  the  Kidney  is  elaborated  from  blood  which 
has  already  passed  through  one  set  of  capillary  vessels,  Distribution  of"the  Renal 
those  of  the  Malpighian  tufts;  this  blood  is  collected  and  vessels;  from  Kidney  of 
conveyed  to  the  proper  secreting  surface,  however,  not  by  Horse:— a,  branch  of  Renal 
one  large  trunk  (which  would  have  been  a  very  inconve-  artery ;  «/,  afferent  vessels ; 
nient  arrangement),  but  by  a  multitude  of  small  ones,  the  OT»  m'  Malpighian  tufts  j  ef, 
efferent  vessels  of  the  Malpighian  bodies  which,  may  be  £^£«±^ 
regarded  as  collectively  representing  the  portal  vein,  since  tbe  tubes.  8tf  straight 
they  convey  the  blood  from  the  systemic  to  the  secreting  tube ;  ct,  convoluted  tube, 
capillaries.  Hence  the  Kidney  may  be  said  to  have  a 

portal  system  within  itself. — This  ingenious  view  of  Mr.  Bowman's  finds  support 
from  the  fact,  that  in  Reptiles  the  efferent  vessels  of  the  Malpighian  bodies  (which 
receive  their  blood,  as  elsewhere,  from  the  renal  artery)  unite  with  the  renal 
branches  of  the  Vena  Portae,  to  form  the  secreting  plexus  around  the  tubuli  uri- 
niferi. Here,  therefore,  the  blood  of  the  secreting  plexus  has  a  double  source, 
the  vessels  which  supply  it  receiving  their  blood  in  part  from  the  capillaries  of 
the  organ  itself,  and  in  part  from  those  of  viscera  external  to  it;  just  as,  in  the 
Liver,  the  secreting  plexus  is  supplied  in  part  by  the  nutritive  capillaries  of  the 
organ  itself,  which  receive  their  blood  from  the  hepatic  artery,  and  in  part  by  the 
blood  conveyed  from  the  chylopoietic  viscera  through  the  vena  portae. 

406.  These  admirable  researches  of  Mr.  Bowman  on  the  structure  of  the 
Malpighian  bodies,  and  on  the  vascular  apparatus  of  the  Kidney,  have  thrown 
great  light  upon  the  mode  in  which  the  Urinary  secretion  is  elaborated.  One  of 
the  most  remarkable  circumstances  attending  this  excretion,  in  the  Mammalia 
particularly,  is  the  large  but  variable  quantity  of  water,  which  is  thus  got-rid  of, 
—  the  amount  of  which  bears  no  constant  proportion  to  that  of  the  solid  matter 
dissolved  in  it.  The  Kidneys,  in  fact,  seem  to  form  a  kind  of  regulating  valve, 
by  which  the  quantity  of  water  in  the  system  is  kept  to  its  proper  amount.  The 
amount  of  exhalation  from  the  Skin,  which,  with  that  from  the  Lungs,  is  the 
other  principal  means  of  removing  superfluous  liquid  from  the  blood,  is  liable  to 
be  greatly  affected  by  the  temperature  and  degree  of  humidity  of  the  air  around 
(§  422) :  hence,  if  there  were  not  some  other  means  of  adjusting  the  quantity 
of  fluid  in  the  blood-vessels,  it  would  be  subject  to  continual  and  very  injurious 
variation.  This  important  function  is  performed  by  the  Kidneys ;  which  allow 
such  a  quantity  of  water  to  pass  into  the  urinary  tubes,  as  may  keep  the  pressure 
within  the  vessels  at  a  nearly  uniform  standard.  The  quantity  of  water  which 
is  passed-off  by  the  Kidneys,  therefore,  will  depend  in  part  upon  that  exhaled  by 
the  Skin ;  being  greatest  when  this  is  least,  and  vice  versa :  but  the  quantity  of 
solid  matter  to  be  conveyed-away  in  the  secretion,  has  little  to  do  with  this, 
being  dependent  upon  the  amount  of  waste  in  the  system,  and  upon  the  quantity 
25 


386  OF    SECRETION    AXD    EXCRETION. 

of  surplus  azotized  aliment  which  has  to  be  discharged  through  this  channel.  — 
The  Kidney  contains  two  very  distinct  provisions  for  these  purposes.  The  cells 
lining  the  tubuli  uriniferi  are  probably  here,  as  elsewhere,  the  instruments 
by  which  the  so/id  matter  of  the  secretion  is  eliminated ;  whilst  it  can  scarcely 
be  doubted,  that  the  office  of  the  Corpora  Malpighiana  is  to  allow  the  transuda- 
tion  of  the  superfluous,  fluid  through  the  thin-walled  and  naked  capillaries  of 
which  they  are  composed.  "  It  would  indeed,"  Mr.  Bowman  remarks  (loc.  cit., 
p.  75),  "  be  difficult  to  conceive  a  disposition  of  parts  more  calculated  to  favour 
the  escape  of  water  from  the  blood,  than  that  of  the  Malpighian  body.  A  large 
artery  breaks-up  in  a  very  direct  manner  into  a  number  of  minute  branches , 
each  of  which  suddenly  opens  into  an  assemblage  of  vessels  of  far  greater  aggre- 
gate capacity  than  itself,  and  from  which  there  is  but  one  narrow  exit.  Hence 
must  arise  a  very  abrupt  retardation  in  the  velocity  of  the  current  of  the  blood. 
The  vessels  in  which  this  delay  occurs,  are  uncovered  by  any  structure.  They 
lie  bare  in  a  cell,  from  which  there  is  but  one  outlet,  the  orifice  of  the  tube. 
This  orifice  is  encircled  by  cilia,  in  active  motion,  directing  a  current  towards  the 
tube.  These  exquisite  organs  must  not  only  serve  to  carry  forward  the  fluid 
which  is  already  in  the  cell,  and  in  which  the  vascular  tuft  is  bathed ;  but  must 
tend  to  remove  pressure  from  the  free  surface  of  the  vessels,  and  so  to  encourage 
the  escape  of  their  more  fluid  contents."  —  Here  we  see  the  essential  difference 
which  exists,  between  the  vital  agency  concerned  in  the  true  Secreting  process, 
and  the  physical  power  which  occasions  fluid  exhalation  or  transudation.  This 
difference  is  precisely  the  same  as  that  which  exists  between  the  vital  act  of  se- 
lective absorption,  and  the  physical  operation  of  endosmose  or  imbibition.  By 
Imbibition  and  Transudation,  certain  fluids  may  pass  through  organic  membranes, 
in  the  dead  as  well  as  in  the  living  body ;  and  this  passage  depends  merely  upon 
the  physical  condition  of  the  part,  in  regard  to  the  amount  and  the  nature  of  the 
fluid  it  contains,  arid  the  permeability  of  its  tissues.  Not  only  does  water  thus 
transude,  but  various  substances  that  are  held  in  complete  solution  in  it,  espe- 
cially albuminous  and  saline  matter :  it  is  in  this  manner  that  the  Blood  absorbs 
fluids  from  the  digestive  cavity  (§  124),  and  pours-out  the  serous  fluid  which 
occupies  the  interspaces  of  the  areolar  tissue  and  the  serous  cavities.  The  trans- 
udation of  the  watery  portion  of  the  blood  is  much  increased  by  any  impediment 
to  its  flow  through  the  vessels,  and  also  by  any  causes  that  produce  a  diminished 
resistance  in  their  walls. 

407.  The  Kidney  is  liable  to  undergo  alterations  of  its  normal  structure,  from 
a  perversion  of  its  ordinary  formative  processes,  which  are  of  a  nature  very 
analogous  to  those  which  have  been  already  described  as  occurring  in  the  Liver, 
though  with  differences  arising  out  of  the  specialities  of  its  conformation. 
Several  different  kinds,  as  well  as  degrees,  of  such  alteration,  have  been  described 
(as  it  now  appears)  under  the  general  term  l  Bright' s  disease/  which  has  been 
applied  almost  indiscriminately  to  almost  every  kind  of  chronic  degeneration  of 
the  structure  of  the  Kidney,  that  is  attended  with  the  presence  of  albumen  in 
the  urine. — In  the  first  place,  there  may  be  mere  vascular  Congestion,  this  espe- 
cially affecting  the  vascular  coil  of  the  Malpighian  bodies,  and  the  secreting 
plexus  around  the  tubuli  uriniferi  of  the  cortical  substance ;  with  this,  however, 
there  is  usually  more  or  less  effusion,  either  of  blood  or  of  fibrinous  exudation, 
into  the  interior  of  the  tubules,  and  sometimes  amidst  the  interstitial  tissue;  and 
the  epithelium  is  very  commonly  thrown-off,  sometimes  presenting  itself  in  the 
urine,  but  often  remaining  entangled  in  the  fibrinous  exudation,  so  as  to  block-up 
the  tubuli.  This  condition  may  be  induced  by  cold,  and  also  by  scarlatina,  as 
well  as  by  other  cutaneous  affections  which  interfere  in  a  considerable  degree 
with  the  ordinary  functions  of  the  skin.  —  When  this  congestion  passes  into  In- 
flammation, the  effusion  becomes  more  completely  organizable;  and  in  the 
changes  which  this  subsequently  undergoes,  it  becomes  the  occasion  of  a  further 
alteration  in  the  proper  substance  of  the  kidney.  The  seat  of  the  plastic  exuda- 


THE    KIDNEYS.  —  SECKETION    OF    URINE.  387 

lion  may  be  either  the  inter-tubular  substance,  or  the  interior  of  the  tubuli.  In 
the  first  case,  it  usually  becomes  developed  into  a  more  or  less  perfect  fibrous 
tissue,  which,  by  undergoing  a  progressive  contraction,  comes  to  press-upon,  and 
at  last  to  obliterate,  many  of  the  blood-vessels  and  tubuli  uriniferi ;  thus  pro- 
ducing a  deficient  supply  of  blood,  and  atrophy  of  the  proper  tissue  of  the 
Kidney,  whilst  the  bulk  of  the  organ  is  generally  augmented  by  the  large  pro- 
portion of  exudation-tissue  which  it  may  include,  though  it  is  sometimes  reduced. 
This  state  is  analogous  in  all  essential  particulars  to  the  cirrhosis  of  the  Liver 
(§  396).  The  plastic  exudation,  on  the  other  hand,  may  be  poured-out  rather 
within  than  around  the  tubes,  thus  directly  blocking  them  up.  In  either  case, 
however,  an  obstruction  to  the  exit  of  the  secreted  fluid  through  any  tube,  whilst 
its  Malpighian  corpuscle  is  still  capable  of  allowing  the  transudation  of  fluid 
through  its  glomerulus,  will  occasion  a  distension  of  the  tube  or  of  its  Malpi- 
ghian capsule  above  the  obstruction ;  and  thus  a  cyst  is  formed,  which  may  itself 
become  filled  with  exudation-substance.  When  the  exudation  is  poured-out  into 
the  interior  of  the  tubuli,  it  seems  to  be  much  more  prone  to  degrading  changes, 
than  when  it  is  effused  into  the  intertubular  substance ;  for  it  seldom  passes  into 
the  fibrous  condition,  but  at  first  presents  a  granular  appearance,  and  speedily 
undergoes  '  fatty  degeneration/  And  this  is  not  ^infrequently  the  case  with  the 
interstitial  deposit,  which  is  often  formed  in  greater  or  less  abundance  when  the 
interior  of  the  tubes  is  also  occupied  by  it;  so  that  the  morbid  product  is  found 
in  all  parts  of  the  gland,  —  the  intertubular  tissue,  the  tubules,  and  the  Malpi- 
ghian capsules,  —  obliterating  a  large  proportion  of  the  normal  structure.  This 
condition  presents  itself,  more  or  less  fully  developed,  in  the  greater  number  of 
fatal  cases  of  '  Bright' s  disease ;'  and  it  is  that  which  first  attracted  attention  as 
1  granular  degeneration/  the  granulations  being  produced  by  the  distension  of 
loops  or  clusters  of  tubules  with  exudation-matter. — It  is  probable  that  in  the 
case  of  the  Kidney,  as  in  that  of  the  Liver,  there  is  an  idopathic  l  fatty  degene- 
ration '  of  the  secreting  cells  (§  397),  without  any  exudation ;  and  this  may 
become  a  source  of  corresponding  perversion  in  the  character  of  the  urinary  se- 
cretion.1 

408.  It  must  not  be  supposed,  however,  that  any  of  the  lesions  now  described 
are  invariably  coincident  with  the  presence  of  Albumen  in  the  Urine;  for  it  has 
been  fully  proved,  on  the  one  hand,  that  albumen  may  present  itself  in  this 
excretion,  without  any  alteration  in  the  structure  of  the  kidney;  and,  on  the 
other,  that  various  forms  of  B  right's  disease  may  exist,  even  in  an  advanced 
stage,  without  any  albumen  being  detectable  in  the  urine.2  These  variations 
may  probably  be  attributed  to  two  classes  of  conditions;  viz.,  the  state  of  the 
albumen  in  the  blood  itself,  and  the  state  of  the  capillary  circulation  in  the  kid- 
ney. We  have  seen  that  the  weak  form  of  albumen  which  is  first  taken  up  by 
absorption  from  the  alimentary  canal,  is  distinguished  by  its  proneness  to  transu- 
dation (§  183) ;  whilst,  on  the  other  hand,  the  strong  albumen  of  the  egg,  if 
injected  into  the  systemic  blood-current,  finds  its  way  out  again  by  the  urine,  as 
a  foreign  substance  (§  132) ;  an  assimilating  action  being  required,  in  the  case 
of  each,  to  give  it  the  normal  characters  of  blood-albumen.  It  is  probably,  in 
part  at  least,  to  the  want  of  such  perfect  assimilation  of  the  newly-absorbed  albu- 
men, that  we  are  to  attribute  the  increase  of  albumen  in  the  urine  passed  soon 
after  meals,  by  patients  suffering  under  Bright's  disease ;  something,  however, 
may  be  due  to  the  simple  augmentation  of  the  bulk  of  the  blood,  and  especially 
of  its  solids.  But,  again,  it  has  been  shown  that  any  cause  which  produces  con- 
gestion of  the  vessels  of  the  kidney,  favours  the  passage  of  the  normal  albumen 
of  the  blood  into  the  urine  ;2  and  thus  we  see  how  albuminous  urine  may  bo 

1  In  the  foregoing  account  of  the  pathological  changes  in  the  Kidney,  -which  constitute 
'Bright's  Disease,'  the  views  of  Frerichs  (in  his  admirable  treatise  "Die  Bright'sche  Nie- 
renkrankheit  und  deren  Behandlung")  have  been  chiefly  followed. 

2  See  Dr.  Begbie  in  the  "Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  xii.  p.  46. 
•  See  Robinson  in  "Med.-Chir.  Transact,"  vol.  xxvi.  p.  51. 


888  OF    SECRETION    AND    EXCRETION". 

produced  by  the  repulsion  of  blood  from  the  cutaneous  surface  to  the  kidney,  or 
by  the  determining  influence  of  cantharides  or  other  irritant  diuretics,  or  by  any 
obstruction  to  the  return  of  blood  from  the  capillary  plexus  by  the  renal  veins. 
Now  it  seems  quite  conceivable,  that,  in  by  far  the  larger  proportion  of  cases,  the 
pressure  of  an  abnormal  deposit  should  be  exercised  in  impeding  the  venous  rather 
than  the  arterial  circulation  in  the  kidney;  and  this  would  well  account  for  the 
very  general  presence  of  albumen  in  the  urine,  in  these  morbid  conditions  of  the 
secreting  organ.  But,  on  the  other  hand,  it  is  no  less  conceivable  that  the  arterial 
current  might  sometimes  be  the  one  chiefly  obstructed,  so  that  there  would  be 
the  very  opposite  to  a  state  of  congestion  in  the  capillaries  and  Malpighian  glo- 
meruli ;  and  it  may  be  in  such  cases  as  these,  that  the  ordinary  symptom  of 
Bright' s  disease  is  wanting. 

409.  The  nature  and  purposes  of  the  Urinary  secretion,  and  the  alterations 
which  it  is  liable  to  undergo  in  various  conditions  of  the  system,  are  much  better 
understood  than  are  those  of  the  Bile  :  this  is  owing,  in  great  part,  to  the  two 
circumstances,  that  it  may  be  readily  collected  in  a  state  of  purity,  and  that  its 
ingredients  are  of  such  a  nature  as  to  be  easily  and  definitely  separated  from 
each  other  by  simple  chemical  means.  There  can  be  no  doubt  that  the  chief 
purpose  of  this  excretion,  is  to  remove  from  the  system  the  effete  azotized  mat- 
ters, which  the  blood  takes-up  in  the  course  of  its  circulation,  or  which  may  have 
been  produced  by  changes  occurring  in  itself.  This  is  evident  from  the  large 
proportion  of  Nitrogen  in  the  solid  matter  dissolved  in  the  urine ;  and  from  the 
crystalline  form  presented  by  much  of  this  solid  matter  when  separated, — a  form 
which  indicates  that  its  state  of  combination  is  such,  as  to  prevent  it  from  con- 
ducing to  the  nutrition  of  the  system.  The  injurious  effects  of  the  retention  of 
the  components  of  the  Urinary  secretion  in  the  Blood,  are  fully  demonstrated  by 
the  results  of  its  cessation ;  whether  this  be  made  to  take  place  experimentally 
(as  by  tying  the  renal  artery),  or  be  the  consequence  of  a  disordered  condition 
of  the  kidney.  The  symptoms  of  Urcemia  (as  this  condition  has  been  appro- 
priately termed)  are  altogether  such  as  indicate  the  action  of  a  specific  poison 
upon  the  Nervous  system ;  affecting  either  the  Brain  or  the  Spinal  Cord  sepa- 
rately, or  both  together.  In  the  first  form,  a  state  of  stupor  comes  on  rather 
suddenly,  out  of  which  the  patient  is  with  difficulty  aroused ;  and  this  gradually 
deepens  into  complete  coma,  with  fixed  pupils  and  stertorous  breathing,  just  as 
in  ordinary  kinds  of  narcotic  poisoning.  In  the  second  form,  convulsions  of  an 
epileptic  character,  frequently  affecting  the  whole  muscular  system,  suddenly 
occur  j  but  there  is  no  loss  of  consciousness.  In  the  third  form,  coma  and  con- 
vulsions are  combined. — It  has  been  generally  supposed  that  these  results  are 
attributable  to  the  accumulation  of  urea  in  the  blood ;  but  clinical  observation 
affords  sufficient  evidence,  that  there  is  no  constant  relation  between  the  severity 
of  these  symptoms  and  the  amount  of  urea  in  the  circulating  system;1  and  expe- 
riment has  determined  that  the  other  constituents  of  the  urine  do  not  exert  any 
more  potent  influence.2  It  seems  probable,  then,  that  some  substance  formed  at 
the  expense  of  the  normal  constituents  of  urine,  rather  than  either  of  these  sub- 
stances themselves,  is  the  real  poisonous  agent  in  cases  of  Uraemia  •  and  very 
cogent  evidence  has  been  adduced  by  Prof.  Frerichs-,  in  proof  of  his  idea  that 
the  symptoms  of  this  disorder  arise  from  the  conversion  of  the  Urea  in  the 
circulating  current  into  Carbonate  of  Ammonia,  by  the  agency  of  a  suitable 
ferment ;  so  that,  however  great  may  be  the  accumulation,  it  does  not  give  rise 
to  any  serious  consequences,  unless  this  ferment  be  also  present.  Two  series  of 

1  It  has  been  remarked  by  Bright,  Christison,  G.  0.  Rees,  and  Frerichs,  that  urea  may 
often  be  obtained  in  considerable  quantity  from  the  blood  of  patients  suffering  under 
•  Bright's  disease,'  who  were  at  the  same  time  free  from  all  nervous  symptoms. 

3  Thus  Frerichs  (as  Bichat,  Courten,  and  Gaspard  had  before  done)  repeatedly  injected 
from  20  to  40  grammes  of  filtered  human  urine,  sometimes  even  with  the  addition  of  urea, 
into  the  veins  of  animals,  without  any  ill  effects  resulting. 


THE  KIDNEYS: — SECRETION  OF  URINE.  389 

experiments  are  described  by  him  as  supporting  this  doctrine;  the  first  showing 
that  in  cases  of  uraemic  intoxication,  a  resolution  of  urea  into  carbonate  of  am- 
monia is  actually  taking  place,  ammonia  being  found  in  the  expired  air  when  the 
first  symptoms  make  their  appearance,  and  in  the  blood  and  in  the  contents  of  ( 
the  stomach  after  death  ;'  and  the  second  proving  that  the  injection  of  carbonate 
of  ammonia  into  the  circulating  current  induces  a  train  of  symptoms  essentially 
corresponding  with  those  of  uraemia,  stupor  and  convulsions  occurring  either 
separately  or  conjointly.2  —  It  seems  not  improbable  that,  as  in  the  case  of  the 
retention  of  Bile  in  the  Blood  (§  401),  many  of  the  minor  as  well  as  of  the 
severer  forms  of  sympathetic  disturbance,  connected  with  disordered  secretion 
from  the  kidney,  are  due  to  this  directly-poisonous  operation  of  the  decomposing 
constituents  of  the  urine,  upon  the  several  organs  whose  function  is  disturbed; 
and  that  many  complaints,  in  which  no  such  agency  has  been  until  recently  sus- 
pected,— especially  Convulsive  affections,  arising  from  a  disordered  action  of  the 
nervous  centres, — are  thus  due  to  the  insufficient  elimination  of  Urea  from  the 
Blood. 

410.  In  order  to  form  a  correct  opinion  of  the  state  of  the  Urinary  secretion 
in  morbid  conditions  of  the  system,  it  is  desirable  to  be  acquainted  with  every 
leading  particular  regarding  its  normal  character. — Fresh  healthy  Urine  is  a  per- 
fectly-transparent, amber-yellow-coloured  liquid,  exhaling  a  peculiar  but  not  dis- 
agreeable odour,  and  having  a  bitterish  saline  taste.  The  only  morphological 
elements  which  it  normally  contains,  are  pavement  epithelium-cells  and  mucus- 
corpuscles  from  the  lining  of  the  urinary  passages ;  which,  however,  are  present 
in  healthy  urine  to  but  a  very  small  amount.  But  in  certain  morbid  states  of 
the  urine,  minute  cylindrical  bodies  are  seen,  in  greater  or  less  abundance,  which 
are  obviously  derived  from  the  tubuli  uriniferi ;  these  are  sometimes  composed 
almost  exclusively  of  the  epithelial  lining  of  the  tubes,  of  which  the  cells  remain 
adherent  to  each  other,  notwithstanding  their  detachment  from  the  basement- 
membrane  beneath  ;  whilst  sometimes  they  are  fibrinous  moulds  of  the  inteiior  of 
the  tubes,  formed  by  exudation  of  plastic  material,  and  containing  blood,  or  pus- 
corpuscles  ;  and  in  other  instances,  again,  they  seem  to  consist  of  nothing  else 
than  the  basement-membrane  of  the  tubes  themselves.  The  first  of  these  forms 
occurs  chiefly  in  desquamative  irritation  of  the  kidneys ;  the  second  as  a  conse- 

1  It  is  the  conclusion  of  MM.  Bernard  and  Barreswil, — from  the  experiments  which  they 
have  performed  to  determine,  why,  after  the  extirpation  of  the  kidneys,  a  period  of  from 
twenty-four  to  forty-eight  hours  always  elapses,  before  the  blood  shows  any  decided  traces 
of  Urea, — that,  under  such  circumstances,  the  urea  is  eliminated  by  the  secretions  of  the 
intestinal  tube,  and  chiefly  by  the  gastric  juice,  in  the  form  of  an  ammoniacal  salt;  and 
that  no  urea  can  be  detected  in  the  blood,  until,  by  a  progressive  diminution  of  the  vital 
powers,  the  intestinal  fluids  become  more  and  more  diminished  in  quantity,  and  the  metas- 
tatic  channels  for  the  elimination  of  urea  are  closed.  Retention  of  urea  in  the  blood,  as 
they  argue,  is  thus  a  result,  not  directly  of  the  suppression  of  urine,  but  rather  of  the 
loss  of  vigour  which  follows  it.  ("  Archiv.  Ge"ner.  de  Me"decine,"  4ieme  Se"r.,  torn,  xiii., 
p.  449). — On  the  metastasis  of  the  Urinary  excretion,  see  \  387. 

3  On  this  subject,  see  the  Chapter  on  '  Uraemia'  in  the  Treatise  of  Frerichs  just  cited. 
His  conclusions,  however,  though  quite  in  harmony  with  the  observations  of  Lehmann 
("Physiological  Chemistry,"  translated  by  Dr.  Day,  vol.  ii.,  p.  253),  have  been  disputed 
by  other  pathologists ;  as  by  Zimmermann,  "  Deutsche  Klink,"  No.  37,  and  "  Brit,  and 
For.  Med.-Chir.  Rev.,"  vol.  xi.,  p.  209;  and  by  Schottin,  "Vierordt's  Archiv.,"  1853, 
hefti.,  p.  170,  and  "Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  xii.,  p.  268.  The  latter  of 
these  critics  aifirms,  that  the  cause  of  the  symptoms  of  uraemic  poisoning,  in  cases  of 
advanced  «  Bright's  disease,'  "  must  be  looked-for  in  an  impediment  of  the  metamorphosis 
of  the  tissues,  in  a  destruction  of  the  process  of  endosmose  and  exosmose  between  blood 
and  tissues,  and  perhaps  in  a  generally-diminished  oxidation-power  in  the  blood." — It  is 
difficult,  however,  to  believe  that  the  narcotic  symptoms  following  upon  sudden  and  com- 
plete  suppression  of  the  urinary  excretion,  with  accumulation  of  urea  in  the  blood  (as 
shown  by  analysis),  and  abating  with  the  elimination  of  the  urea  by  the  re-establishment 
of  the  secretion  (as  happened  in  the  interesting  case  recorded  by  Dr.  Shearman  in  the 
"Edinb.  Monthly  Journal,"  March,  1848),  can  be  due  to  anything  else  than  the  direct 
toxic  influence  of  the  urea,  or  of  some  product  of  its  metamorphosis. 


390  OF    SECRETION    AND    EXCRETION. 

quence  of  acute  inflammation,  and  the  last  in  the  advanced  stages  of  '  Bright's 
disease.' — In  all  natural  conditions  of  the  Human  system  (even  when  a  vegetable 
diet  is  used),  the  urine  possesses  a  well-marked  acid  reaction.  When  it  is  left 
to  itself  for  some  time,  slight  nebulae,  consisting  of  mucus,  are  formed  in  it ;  and 
these  gradually  descend  to  the  bottom.  Soon  afterwards,  an  unpleasant  odour  is 
developed;  instead  of  an  acid,  an  alkaline  reaction  is  presented,  in  consequence 
of  the  decomposition  of  the  urea  into  carbonate  of  ammonia;  and  a  precipitation 
of  earthy  phosphates  then  takes  place.  A  turbidity  may  be  produced,  however, 
by  the  precipitation  of  urates  of  soda  and  ammonia,  on  the  simple  cooling  of  the 
urine,  without  any  such  departure  from  its  normal  composition  as  would  properly 
constitute  disease,  but  under  some  of  the  conditions  hereafter  to  be  specified 
(§  412).  But  if  the  urine  be  turbid,  wlien  it  is  first  passed  from  the  body,  and 
has  a  temperature  of  98°  or  100°,  it  must  be  considered  as  abnormal. — The  ave- 
rage Quantity  of  urine  passed  during  the  24  hours,  has  been  variously  estimated : 
it  differs,  of  course,  with  the  amount  of  fluid  ingested,  and  it  is  influenced  also 
by  the  external  temperature ;  a  much  smaller  amount  of  the  superfluous  fluid  of 
the  body  being  set-free  from  the  skin  in  winter  than  in  summer,  and  a  larger 
proportion  being  carried-off  by  the  kidneys.  Probably  we  shall  be  pretty  near 
the  truth,  in  estimating  the  amount  (with  Dr.  Prout)  at  from  about  30  oz.  in 
summer,  to  40  oz.  in  winter,  for  a  person  who  does  not  drink  more  than  the 
simple  wants  of  nature  require.- — The  Specific  Gravity  comes  to  be  a  very  im- 
portant character,  in  various  morbid  conditions  of  the  urine ;  and  it  is  therefore 
desirable  to  estimate  it  correctly.  This  also  is  of  course  subject  to  the  like 
causes  of  variation ;  since,  when  the  same  amount  of  solid  matter  is  dissolved  in 
a  larger  or  smaller  quantity  of  water,  the  specific  gravity  will  be  proportionably 
lower  or  higher;  or,  the  quantity  of  water  remaining  the  same,  an  increase  or 
diminution  in  the  amount  of  solid  matter  will  raise  or  lower  the  specific  gravity. 
It  has  been  commonly  supposed  that  the  amount  of  solid  matters  in  the  urine 
bears  such  a  constant  ratio  to  its  specific  gravity,  that  the  former  may  be  approxi- 
matively  deduced  from  the  latter;  this,  however,  has  been  clearly  shown  to  be 
by  no  means  the  case.1  Still,  the  determination  of  the  specific  gravity  is  of 
sufficient  importance  for  diagnostic  purposes,  to  make  it  desirable  to  possess  an 
average  standard,  as  nearly  approaching  to  accuracy  as  circumstances  will  permit. 
The  average,  according  to  Dr.  Prout,  in  a  healthy  person,  taking  the  whole  year 
round,  is  about  1020;  the  standard  rising  in  summer  (on  account  of  the  greater 
discharge  of  fluid  by  perspiration)  to  1025 ;  and  being  lowered  in  winter  to  1015. 
Simon,  however,  states  the  average  specific  gravity  at  no  more  than  1012.  It 
will  mainly  depend,  in  each  individual  case,  upon  the  amount  of  azotized  solids 
and  of  aqueous  fluids  habitually  ingested,  allowing  for  the  portion  of  the  latter 
that  is  dissipated  by  cutaneous  exhalation ;  and  it  will  also  vary  with  the  period 
that  has  elapsed  since  the  last  introduction  of  liquid  into  the  stomach.  From 
these  and  other  causes,  the  amount  of  solid  matter  in  1000  parts  of  Urine  may 
vary  from  20  to  70  parts;  and  hence  the  various  recorded  analyses  of  this  liquid 
present  very  wide  diversities  in  the  proportions  of  its  solid  constituents.2  These 
discrepancies,  however,  being  chiefly  due  to  the  fluctuating  amount  of  water,  be- 
come very  much  less  (as  Simon  pointed  out)  when  we  calculate  the  proportion 
which  each  principal  component  bears  to  100  of  solid  residue ;  as  is  shown  in  the 
following  Table : — 

1  See  "  Lehmann's  Physiological  Chemistry,"  (Cavendish  Society),  vol.  ii.  p.  436. 

a  It  is  remarked  by  Lehmann  (Op.  cit.,  p.  447),  that  the  urine  of  the  French  is  poorest 
in  solid  constituents,  especially  in  urea  and  uric  acid,  and  that  of  the  English  the  richest, 
that  of  the  Germans  being  intermediate  between  the  two ;  the  ratio  in  each  nation  being 
in  conformity  with  the  proportion  of  animal  food  entering  into  its  ordinary  diet. 


THE    KIDNEYS. —  SECRETION    OF    URINE  391 

Berzelius.  Lehmann.  Simon.  Marchnnd. 

Urea 45-10  49-68  33-80  48-91 

Uric  acid 1-50  1-61  1-40  1-59 

Extractive  matter  Ammonia-salts,  i  86.80  28.%  42.60  g2.49 

and  Chloride  of  Sodium \ 

Alkaline  Sulphates 10-30  11-58  1-14  10-18 

Alkaline  Phosphates 6-88  5-96  6-50  4-57 

Phosphates  of  Lime  and  Magnesia....  1-50  1-97  1-59  1-81 

We  shall  presently  find  the  causes  of  some  of  the  variations  even  here  shown,  to 
lie  in  the  nature  of  the  ingesta,  and  in  the  amount  of  exercise  taken  by  the  indi- 
vidual. 

411.  The  most  important  of  those  organic  constituents  of  the  Urine,  whose 
presence  may  be  directly  traced  to  the  metamorphosis  of  the  azotized  components 
of  the  tissues  and  of  the  blood  (§  348),  is  evidently  that  which,  from  its  being 
the  principal  source  of  the  characteristic  properties  of  the  secretion,  is  termed 
Urea.  This  substance,  as  already  mentioned  (§172),  exists  preformed  in  the 
Blood,  though  ordinarily  in  very  small  amount;  being  generated  by  the  retro- 
grade metamorphosis  of  the  azotized  tissues,  especially  the  Muscular  (and  in  this 
probably  through  the  intermediation  of  creatine  or  of  uric  acid),  and  also  by  simi- 
lar changes  in  the  unassimilated  portions  of  the  Blood  itself. — The  amount  of 
Urea  excreted  in  the  24  hours  has  been  made  the  subject  of  examination  by  nu- 
merous Chemists :  the  following  are  the  results  deduced  by  M.  Lecanu1  from  a 
series  of  120  analyses  : — 

Minimum.  Mean.  Maximum. 

By  Men 357-51  grs.  433-13  grs.  51036grs. 

By  Women 153-25    ,,  295-15    „  437-06    „ 

By  Old  Men  (84  to  86  years)....     61-08    „  125-22    „  295-15    „ 

By  Children  of  eight  years 161-78    „  207-99    „  254-20    „ 

By  children  of  four  years 57-28    „  69-55    „  81-83    „ 

The  averages  obtained  by  Scherer,  Bischof,  and  other  subsequent  experimenters, 
are  very  closely  conformable  to  these  (allowance  being  made  for  the  difference  of 
habitual  diet  already  referred-to,  §  410  note) ;  and  their  observations  all  agree, 
moreover,  in  assigning  a  like  high  proportion"  to  the  excretion  of  urea  in  children, 
as  compared  with  the  weight  of  their  bodies.  Thus  Scherer2  states  that  whilst 
an  adult,  for  every  1  Ib.  weight  (avord.)  of  his  body,  daily  excretes  2-94  grains 
of  urea,  a  child  excretes  5-67  grains  of  urea  for  every  1  Ib.  weight  of  his  body. 
This  excessive  proportion  of  urea  in  young  subjects  may  be  considered  as  depend- 
ent on  the  rapidity  of  interstitial  change  in  their  tissues ;  while  the  reverse  of 
both  is  true  of  aged  subjects.  (See  CHAP,  xviil.)  The  quantity  of  Urea 
secreted  at  any  given  period  of  life,  seems  to  depend  mainly  on  two  conditions ; 
namely,  the  degree  of  muscular  exertion  previously  put-forth,  and  the  amount  of 
azotized  matter  ingested  as  food.  Thus  Prof.  Lehmann  ascertained  that,  by  the 
substitution  of  violent  for  moderate  exercise,  the  quantity  of  Urea  was  raised 
from  32£  to  45J  parts ;  and  Simon  found  that,  by  two  hours'  violent  exercise,  the 
proportion  of  the  urea  in  the  urine  passed  half  an  hour  subsequently,  was  double 
that  contained  in  the  morning-urine.  Again,  Prof.  Lehmann  has  shown  (§417) 
that  the  amount  of  Urea  excreted  daily,  when  no  azotized  matter  was  taken-in  as 
food,  and  when  the  excretion  was  simply  a  measure  of  the  *  waste'  of  the  tissues, 
was  not  above  halfih&t  excreted  when  an  ordinary  mixed  diet  was  employed,  and 
only  about  two-sevenths  of  that  which  was  passed  when  the  diet  was  purely  ani- 
mal. The  recent  experiments  of  Prof.  Bischof  are  to  the  same  effect;  for  ho 
found  that  a  large  dog  secreted,  with  mixed  food,  from  230  to  300  grains  of  urea 
daily;  with  flesh  diet,  802  grains;  and  when  fed  on  intestines  and  gelatine,  no 
less  than  1110  grains  daily.  This  last  statement  confirms  the  inference  to  which 
the  injection  of  a  solution  of  Gelatin  directly  into  the  blood  appears  to  lead  (§  51); 

1  "Journal  de  Pharmacie,"  torn.  xxv. 

9  »  Verhandl.  d.  phys-med.  Ges.  zu  Wurzburg,"  band  ii.  pp.  280-290. 


392  OF    SECRETION    AND    EXCRETION. 

namely,  that  urea  may  be  formed  directly  from  the  metamorphosis  of  this  sub- 
stance, and  probably,  therefore,  from  the  disintegration  of  the  gelatinous  as 
well  as  of  the  albuminous  tissues. — The  observations  of  Bidder  and  Schmidt  upon 
the  quantity  of  urea  excreted  by  a  cat  fed  exclusively  upon  fat  meat  in  varying 
proportions,  led  them  to  conclude  that  this  animal  separates  by  the  kidneys  6-8 
parts  of  urea  for  every  100  parts  of  flesh  which  it  consumes  ;  this  amount  of  urea 
containing  about  six-sevenths  of  the  nitrogen  contained  in  the  food.  The  meta- 
morphosis of  tissue  would  seem  to  proceed  in  Carnivorous  animals  at  a  far  more 
rapid  rate  than  in  Man ;  for  this  cat  excreted  on  an  average  as  much  as  14-77 
grains  of  urea  for  every  1  Ib.  (avord.)  weight  of  its  body,  even  when  inanitiated; 
whilst,  if  highly  fed  with  flesh,  it  excreted  no  less  than  53-62  grains  daily,  for 
every  1  Ib.  weight  of  its  body. — The  foregoing  facts  seem  to  afford  full  confirma- 
tion to  the  doctrine  already  stated  (§  381),  and  advanced  by  the  Author  many 
years  ago,1  that  the  amount  of  urea  in  the  urine  can  only  be  regarded  as  a  mea- 
sure of  the  metamorphosis  of  tissue,  when  no  more  food  is  ingested  than  is 
required  to  compensate  for  that  metamorphosis ;  any  histogenetic  matter  which 
escapes  assimilation  through  not  being  required  in  the  system,  being  normally 
decomposed,  and  its  azotized  portion  eliminated  through  this  channel.2 — The 
amount  of  urea  excreted  daily,  is  usually  (though  not  constantly)  increased  in 
febrile  diseases ;  and  when  it  is  borne  in  mind  that  comparatively  little  food  is 
taken  under  such  circumstances,  the  increase  must  be  wholly  set-down  to  the 
account  of  the  more  rapid  wasting  of  the  tissues.  In  fact,  an  absence  of  increase, 
or  even  a  certain  amount  of  diminution,  when  the  supply  of  food  has  almost  en- 
tirely ceased,  would  still  indicate  an  excess  of  '  waste.'  Some  valuable  observa- 
tions on  this  point  have  been  recently  made  by  Dr.  A.  Vogel;3  who  has  found 
that  in  a  case  of  typhoid  fever,  no  less  than  1065?  grains  of  urea  were  excreted 
daily  (or  nearly  double  the  usual  average  for  Germany,  which  is  stated  by  Prof. 
Bischof  at  540£  grains),  and  in  a  case  of  pyaemia,  the  extraordinary  quantity  of 
1235  J  grains.  When  the  fever  is  over,  the  quantity  of  urea  falls  below  the  nor- 
mal amount,  in  spite  of  the  augmented  quantity  of  nitrogenous  food  ingested, 
which  is  doubtless  appropriated  to  the  repair  of  the  wasted  tissues;  and  it  then, 
after  perfect  recover}^,  returns  to  the  physiological  standard. 

412.  Next  in  importance  to  Urea,  among  the  organic  products  of  the  meta- 
morphosis of  the  azotized  constituents  of  the  tissues  or  of  the  blood,  but  ordina- 
rily bearing  a  very  small  proportion  to  it  in  quantity,  is  Uric  acid.  The  forma- 
tion of  this  substance  is  probably  anterior  to  that  of  urea ;  and  we  shall  see  that 
its  proportion  in  the  urine  is  augmented  under  the  same  conditions  as  regards 
food  (§  417).  On  the  other  hand,  there  is  reason  to  think  that  exercise,  by 
augmenting  the  respiration,  tends  to  diminish  the  proportion  of  uric  acid  in  the 
urine,  by  converting  it  into  urea,  whilst  yet  in  the  circulating  current;  for  this 
conversion  may  be  effected  by  boiling  it  with  peroxide  of  lead,  which,  by  yield- 
ing oxygen,  causes  the  resolution  of  uric  into  urea  and  oxalic  acid,  the  latter 
being  converted  by  a  further  process  of  oxidation  into  carbonic  acid.  The  cir- 
cumstances that  most  favour  the  genesis  of  uric  acid  in  the  system,  therefore,  and 
the  increase  of  its  proportion  in  the  urine  if  there  be  no  obstacle  to  its  elimination, 
are  a  highly-azotized  diet  and  inactive  habits ;  whilst  the  reduction  of  the  azotized 
portion  of  the  diet  to  what  is  really  wanted  for  the  nutrition  of  the  system,  and 
the  promotion  of  the  respiration  by  active  exercise,  tend  to  reduce  the  proportion 
of  this  component.  The  precipitation  of  uric  acid  (usually  in  combination  with 
•soda  or  ammonia,  or  both),  which  frequently  takes-place  on  the  cooling  of  the 
urine,  must  not  be  regarded  as  indicative  of  the  presence  of  an  unusual  amount 

1  "Brit,  and  For.  Med.  Rev.,"  vol.  xv.  p.  503. 

3  See  a  valuable  article  on  "The  Metamorphosis  of  Tissue,"  giving  an  account  of  the 
researches  of  Bidder  and  Schmidt,  Bischof,  and  others,  in  relation  to  the  genesis  of  the 
solids  of  the  Urine,  in  "  Brit,  and  For.  Med.-Chir.  Rev.,"  vol.  xiii.  p.  384. 

'  "  Zeitschrift  fur  Ration.  Med.,"  baud  iv.  heft  3. 


THE  KIDNEYS.  —  SECRETION  OF  URINE,       393 

of  this  substance  ;  since  it  may  depend  upon  other  conditions.  It  seems  to  have 
been  clearly  proved  by  Dr.  Bence  Jones,1  that  there  is  no  relation  whatever 
between  the  acidity  of  the  urine,  and  the  absolute  amount  of  Uric  acid  which  it 
may  contain ;  for  in  the  urine  which  is  most  acid,  and  which  deposits  the  largest 
uric-acid  sediment,  very  little  uric  acid  may  really  exist ;  whilst  that  which  con- 
tains most  uric  acid  may  hold  it  in  perfect  solution,  and  may  have  but  a  feeble 
acid  reaction.  The  main  cause  of  the  deposit  of  Uric-acid  sediments,  is  doubtless 
the  presence  of  some  other  acid ;  for  the  addition  of  any  acid  to  healthy  urine 
passed  soon  after  food,  is  always  sufficient  to  produce  it.  But  the  deposit  takes 
place  less  readily  if  the  temperature  of  the  fluid  be  high,  since  the  solvent  power 
of  the  acid  phosphate  of  soda  is  then  more  strongly  exerted ;  so,  on  the  other 
hand,  a  deposit  often  takes  place  in  urine  which  would  not  otherwise  exhibit  it, 
through  an  unusual  reduction  in  its  temperature,  as  by  exposure  to  the  cold  air 
of  a  sleeping-room  in  the  winter.  Again,  the  deposit  of  uric-acid  sediment  is 
favoured  by  concentration  of  the  liquid,  which  thus  augments  the  proportion  of 
the  urate  to  the  water,  and  at  the  same  time  intensifies  the  acid  reaction ;  and 
thus  urine  whose  constituents  are  otherwise  normal,  may  throw  down  a  copious 
deposit  of  this  kind,  merely  from  deficiency  of  water;  whilst  an  unusual  amount 
of  uric  acid  may  be  readily  present  without  being  deposited, — the  urine,  too, 
exhibiting  its  ordinary  acidity, — if  the  proportion  of  water  be  large.  Thus  the 
uric-acid  sediment  may  be  regarded  as  dependent  upon  three  concurrent  condi- 
tions ; — (1)  Decrease  of  temperature  j  (2)  Increased  proportion  of  uric-acid  com- 
pound to  the  water,  positively  or  relatively,  (3)  Increased  acidity  of  the  urine. 
Sometimes  one  condition  is  most  influential,  sometimes  another;  but  they  are  all 
usually  concerned. in  some  degree. — There  are  many  diseases,  especially  those  of 
a  febrile  nature,  in  which  the  presence  of  an  excess  of  uric  acid  is  a  very  marked 
symptom ;  there  is  often,  at  the  same  time,  a  reduction  in  the  proportion  of 
urea ;  and  thus  it  would  seem  that,  with  perhaps  an  augmented  tendency  to  dis- 
integration of  the  tissues,  there  is  an  incapacity  for  the  performance  of  that  higher 
process  of  oxidation,  which  is  requisite  for  the  genesis  of  urea ;  so  that  a  larger 
proportion  of  the  products  of  the  waste  passes-off  in  the  state  of  uric-acid,  as  in 
animals  whose  respiration  is  feeble. — This  view  derives  support  from  the  fact, 
that  Hippuric  acid,  which  is  to  be  found  only  in  extremely  minute  proportion 
in  healthy  Human  urine,  and  the  large  proportion  of  carbon  in  which  indicates 
that  it  is  to  be  regarded  as  a  result  of  very  imperfect  oxidation,  undergoes  a 
marked  increase  under  the  same  circumstances ;  and  especially  when  obstructed 
action  exists  in  either  of  the  other  great  emunctories,  so  that  a  larger  amount 
of  carbonaceous  matter  is  thrown  upon  the  kidneys  for  elimination ;  for  in  this 
case,  also,  there  is  a  deficiency  in  the  normal  amount  of  Urea. — Hence,  wherever 
there  is  an  actual  excess  of  Uric  acid  in  the  system,  constituting  the  true  '  uric 
acid  diathesis/  diet,  exercise,  and  the  promotion  of  the  other  excretions,  afford  the 
most  effectual  means  of  controlling  it. 

413.  Although  the  presence  of  Creatine  and  Creatinine  in  the  Urine,  the 
former  in  very  small  proportion,  but  the  latter  in  considerably  larger  amount,  is 
now  a  well-established  fact,  the  actual  quantities  ordinarily  excreted,  and  the 
circumstances  which  favour  their  increase  and  diminution,  have  not  yet  been 
determined.  From  the  ready  convertibility  of  Creatine  into  Creatinine  and  Urea, 
and  from  the  fact  that  in  the  '  juice  of  flesh '  there  is  far  more  of  Creatine  than 
of  Creatinine,  whilst  in  the  Urine  the  proportions  are  reversed,  it  seems  likely 
that  Creatine  is  one  of  the  first  products  of  the  disintegration  of  muscular  tissue, 
and  that  a  portion  of  the  urea  eliminated  in  the  urine,  as  well  as  the  greater  part 
(if  not  the  whole)  of  the  Creatinine,  is  generated  at  its  expense. — The  presence 
of  Lactic  acid  in  the  Urine,  although  by  no  means  infrequent,  must  be  regarded 
as  exceptional.  A  constant  genesis  of  this  substance  is  taking  place  in  the  body, 

1  See  his  'Contributions  to  the  Chemistry  of  the  Urine,'  in  "Philos.  Trans.,"  1848 


394  OF    SECRETION    AND    EXCRETION. 

not  merely  as  a  product  of  the  metamorphosis  of  the  saccharine  matters  employed 
as  food,  but  also  as  one  of  the  results  of  the  disintegration  of  the  azotized  tissues; 
but  the  respiratory  process  affords  the  ordinary  channel  for  its  removal ;  so  that 
it  is  only  when  its  production  is  excessive,  or  when  there  is  some  obstruction  to 
its  elimination  by  the  lungs,  that  it  makes  its  appearance  in  the  urine.  These  con- 
ditions are  so  often  present  in  disease,  that  Lactic  acid  is  far  more  commonly  present 
in  abnormal  than  in  normal  states  of  the  secretion. — The  Extractive  Matters  of 
the  Urine  are  made-up  of  a  variety  of  different  compounds,  our  knowledge  of 
which  is  gradually  being  extended.  Among  the  substances  which  rank  under 
this  head  in  the  ordinary  analyses  of  Urine,  are  creatine,  creatinine,  and  hippuric 
acid ;  and  others  are  being  successively  determined.  Thus  Stadeler  has  shown 
that  the  '  extractive'  of  the  Urine  of  the  Cow  contains  a  peculiar  azotized  com- 
pound, and  several  volatile  non-azotized  acids,  analogous  to,  and  in  one  instance 
absolutely  identical  with,  the  products  of  the  imperfect  oxidation  of  wood  or  coal.1 
And  Prof.  Ronalds  has  shown,  that  the  f  extractive '  of  Human  urine  ordinarily  con- 
tains a  sulphurized  and  a  phosphorized  compound,  which  serve  for  the  excretion  of 
sulphur  and  phosphorus  in  an  unoxidized  state.2  The  Urine-Pigment,  again,  has 
been  to  a  certain  extent  separated  as  a  definite  compound  from  the  f  extractive/ 
especially  by  the  researches  of  Heller,3  and  although  there  is  still  much  uncertainty 
as  to  its  precise  character  (whether,  for  example,  it  is  composed  of  two  or  more 
distinct  substances),  there  is  no  doubt  as  to  the  very  large  proportion  of  carbon  it 
contains;  this  element  constituting  as  much  as  58 £  per  cent,  of  the  ordinary 
pigment,  62 £  per  cent,  of  the  substance  termed  purpurine,  which  is  generated  by 
the  action  of  hydrochloric  acid  on  urine-pigment,  and  even  65 1  per  cent,  of  the 
colouring  matter  of  th^e  urine  of  patients  suffering  under  febrile  disorders  or 
organic  disease  of  the  liver,  in  which  bile-pigment  often  passes  into  the  urine.4 — 
On  the  whole,  we  may  say  that  with  the  exception  of  Creatine  and  Creatinine, 
all  the  known  constituents  of  the  *  Urinary  extractive '  are  substances  which  are 
rich  in  carbon  and  comparatively  poor  in  nitrogen  ;  so  that  their  increase  will  be 
favoured  by  an  excess  of  carbonaceous  food,  an  imperfect  action  of  the  liver,  and 
a  low  degree  of  respiration;  whilst,  on  the  other  hand,  a  highly-azotized  diet, 
especially  if  combined  with  active  exercise,  will  tend  to  their  reduction. 

414.  Besides  its  organic  materials,  the  Urine  contains  a  considerable  amount 
of  Saline  matter;  the  excretion  of  which,  in  a  state  of  solution,  appears  to  be 
one  of  the  principal  offices  of  the  Kidney.  Various  saline  compounds  are  being 
continually  introduced  with  the  food ;  and  others  are  formed  within  the  system, 
by  the  oxidation  of  the  Sulphur  and  Phosphorus  of  the  tissues  or  of  the  food, 
and  by  the  combination  of  the  sulphuric  and  phosphoric  acids  thus  formed,  with 
alkaline  and  earthy  bases  which  the  food  may  contain,  usually  in  a  state  of  com- 
bination with  weaker  acids  which  are  otherwise  disposed-of.  Thus  the  Saline 
compounds  found  in  the  urine,  are  to  be  regarded  as  partly  proceeding  from  the 
retrograde  metamorphosis  of  the  materials  of  the  tissues,  after  these  have  served 
their  purpose  in  the  economy,  and  partly  from  that  of  such  components  of  the 
food,  as,  being  superfluous,  do  not  undergo  organization.  But  the  Kidney  also 
serves  as  the  channel  for  the  elimination  of  saline  compounds  introduced  into 
the  system  per  se ;  these  being  sometimes  normally  present  in  the  body,  but  in- 
gested in  too  large  an  amount,  as  is  often  the  case  with  common  Salt;  whilst,  on 
the  other  hand,  they  may  be  altogether  foreign  to  the  composition  alike  of  its 
solids  and  of  its  fluids. — The  Alkaline  Sulphates  usually  constitute,  as  we  have 
seen  (§  410),  about  10  per  cent  of  the  whole  solid  matter  of  the  Urine.  Being 
always  in  solution,  however,  they  never  make  their  presence  known  by  the  for- 

*  See  Dr.  Gregory's  "  Handbook  of  Organic  Chemistry,"  p.  450. 

3  See  "Philosophical  Transactions,"  1846,  pp.  461-464. 

*  "Arch,  fur  Chernie  und  Mikrosk.,"  band  ii.  pp.  161,  173. 

4  See  Dr.  Golding  Bird's  'Lectures  on  Therapeutics,'  in  "  Med.  Gaz.,"  1848,  vol.  xlii 
229. 


THE    KIDNEYS.  —  SECRETION      OF    URINE.  395 

mation  of  sediments,  and  are  only  to  be  detected  by  chemical  tests.  The  causes 
which  influence  their  amount  have  been  carefully  studied  by  Dr.  Bence  Jones ; 
who  has  shown  that  they  vary  (like  urea)  with  the  amount  of  food  ingested,  and 
with  the  degree  of  nervo-muscular  activity  put-forth ;  as  might  be  anticipated 
from  the  fact,  that,  under  ordinary  circumstances,  the  sulphuric  acid  is  entirely 
formed  within  the  system,  by  the  oxidation  of  the  sulphur  of  the  protein-com- 
pounds, the  bases  being  furnished  by  the  alkaline  carbonates  or  phosphates  of  the 
blood.  When  sulphuric  acid  or  soluble  sulphates  are  taken  into  the  system,  per 
se,  they  partly  find  their  way  out  of  it  by  the  Kidneys ;  the  proportion  of  sul- 
phuric acid  in  the  urine  being  for  a  time  augmented,  although  the  increase  is 
not  considerable  until  some  hours  have  elapsed  after  the  introduction  of  these 
substances  into  the  stomach.1 — The  amount  of  Alkaline  Phosphates  in  the  Urine 
is  usually  about  half  that  of  the  alkaline  sulphates.  The  acid  of  these  also  is  ordi- 
narily generated  within  the  system,  by  the  oxidation  of  the  phosphorus  originally 
introduced  in  the  protein-compounds  ;  and  thus,  as  in  the  case  of  the  sulphates, 
the  quantity  of  them  which  is  excreted  by  the  urine  bears  a  certain  relation  to 
the  amount  of  these  compounds  ingested  as  food,  and  also  to  the  amount  of  mus- 
cular tissue  which  has  undergone  disintegration  by  exercise.  But  it  further 
appears  that  there  is  a  special  relation  between  the  quantity  of  the  alkaline  phos- 
phates in  the  urine,  and  the  amount  of  disintegration  of  the  nervous  tissue;  as 
might  have  been  suspected  from  the  fact,  that  this  tissue  is  distinguished  by  the 
very  large  proportion  of  phosphorus,  united  with  fatty  acids,  which  it  contains. 
And  a  marked  increase  of  these  salts  is  observed  in  those  inflammatory  diseases 
of  the  brain,  in  which  there  is  reason  to  believe  that  an  unusually-rapid  disinte- 
gration of  its  texture  is  taking  place.2 — The  Earthy  Phosphates  usually  bear  but 
a  small  proportion  to  the  Alkaline;  but  their  presence  in  the  urine  comes  to  be 
of  great  importance,  with  reference  to  the  precipitates  which  they  form  in  par- 
ticular conditions  of  that  secretion.  From  the  researches  of  Dr.  Bence  Jones 
(loc.  cit.)  it  appears,  that  the  quantity  of  these  phosphates  in  the  urine  chiefly 
varies  with  the  amount  of  them  contained  in  the  food,  into  many  articles  of 
which  they  enter  largely ;  but  he  has  also  ascertained  that  their  formation  within 
the  system  is  determined  by  the  presence  of  their  bases ;  for  if  any  earthy  salt, 
a  little  chloride  of  calcium  or  sulphate  of  magnesia  for  instance,  be  taken  into 
the  system,  the  quantity  of  earthy  phosphates  in  the  urine  undergoes  an  increase. 
The  small  quantity  of  carbonate  of  lime  taken  into  the  system  with  the  food,  or 
set-free  by  the  slow  disintegration  of  the  osseous  tissue,  is  probably  excreted  in 
Man  almost  entirely  in  the  form  of  phosphate ;  although  of  the  much  larger 
amount  ingested  by  herbivorous  animals,  a  considerable  proportion  is  excreted  in 
the  urine  in  its  original  state.  The  Earthy  Phosphates,  although  insoluble  in 
water,  are  soluble  in  all  acid  liquids;  and  they  are  held  in  solution  in  Urine, 
like  the  urates,  by  the  acid  phosphate  of  soda.  Their  precipitation  in  an  alka- 
line state  of  the  urine  is  owing  to  the  want  of  this  solvent,  not  to  an  excess  in 
their  production ;  for,  as  Dr.  Bence  Jones  has  pointed-out,  that  excess  of  alkaline 
and  earthy  phosphates  in  the  urine  which  constitutes  the  true  '  phosphatic  dia- 
thesis/ is  generally  coincident  with  a  highly-acid  state  of  the  urine. — The  only 
other  inorganic  saline  constituent  of  the  Urine,  whose  quantity  gives  it  import- 
ance, is  Chloride  of  Sodium.  By  far  the  larger  proportion  of  this  is  doubtless 
derived  directly  from  the  food ;  but  little  being  furnished  by  the  disintegration 
of  muscle,  which  will  set-free  potash  rather  than  soda.  The  amount  eliminated 

1  Dr.  Bence  Jones  in  "Philosophical  Transactions,"  1849. 

9  See  Dr.  Bence  Jones's  valuable  series  of  Papers  in  the  "Philosophical  Transactions" 
for  1845,  1847,  and  1850,  and  in  the  "  Medico-Chirurgical  Transactions"  for  1847  and 
1850. — It  is  curious  to  observe,  that  whilst  the  increase  in  the  alkaline  phosphates  in  In- 
flammatory affections  of  the  nervous  centres  is  very  marked,  there  appears  to  be  a  positive 
diminution  of  them  in  Delirium  Tremens.  A  certain  allowance  must  be  made,  however, 
for  the  abstinence  from  food,  which  will  of  itself  occasion  a  reduction  in  the  quantity 
excreted. 


396          OF  SECRETION  AND  EXCRETION. 

by  the  urine  is  consequently  subject  to  great  variation,  it  being  the  JV^fcion  of 
the  Kidneys  to  remove  whatever  is  superfluous,  so  as  to  prevent  the  blood  from 
becoming  overcharged  with  this  substance.  Of  the  chloride  of  sodium  intro- 
duced as  food,  a  part  appears  to  undergo  decomposition  in  the  system,  whereby 
hydrochloric  acid  is  furnished  to  the  gastric  fluid,  and  soda  to  the  bile;  much  of 
this  acid,  however,  must  reunite  with  its  base  in  the  alimentary  canal,  so  that  the 
chloride  of  sodium  thus  regenerated  will  be  absorbed  with  the  products  of  the 
digestive  operation. — Although  Nitric  Acid  can  scarcely  be  regarded  as  a  normal 
constituent  of  the  Urine,  yet  the  investigations  of  Dr.  Bence  Jones l  appear  to 
show  that  it  is  formed  by  a  combustive  process  within  the  body,  whenever  ammo- 
niacal  salts  are  introduced  into  the  system ;  its  amount,  however,  being  very 
small.  He  has  also  found  that  it  is  generated  after  the  ingestion  of  small  quan- 
tities of  urea ;  a  fact  which  affords  some  confirmation  to  the  doctrine  of  Frerichs 
(§  409),  that  urea  may  undergo  decomposition  into  carbonate  of  ammonia,  whilst 
still  circulating  in  the  current  of  blood.  —  The  presence  of  Oxalic  Acid  in  the 
urine  (in  combination  with  Lime)  has  been  usually  regarded  as  a  pathological 
phenomenon,  consequent  upon  an  irregular  performance  of  the  retrograde  meta- 
morphosis of  the  tissues ;  but  there  can  be  no  doubt  that  it  may  also  result  from 
the  presence  of  soluble  salts  of  oxalic  acid  in  certain  articles  of  vegetable  food  2 
415.  The  ordinary  acid  reaction  of  the  Urine  appears  to  be  due,  not  to  the 
presence  of  any  free  acid,  but  to  the  conversion  of  the  basic  phosphate  of  soda 
into  the  acid  phosphate,  by  the  subtraction  of  a  part  of  the  base,  which  occurs 
when  uric,  hippuric,  lactic,  or  other  free  acids  come  into  contact  with  the  former 
substance.  There  is  no  adequate  reason  to  believe,  that,  in  the  healthy  state, 
there  is  ever  any  other  cause  than  this ;  although  in  morbid  urine,  free  organic 
acids  are  almost  certainly  present.3  It  has  been  shown  by  the  researches  of  Dr. 
Bence  Jones,4  however,  that  the  acid  reaction  is  far  from  being  constant  in  its 
degree,  even  when  an  ordinary  mixed  diet  is  steadily  employed ;  for  that  it  varies 
at  different  periods  of  the  day,  increasing  and  decreasing  inversely  with  the 
acidity  of  the  stomach  (§  98).  Thus  the  acidity  of  the  Urine  decreases  soon 
after  taking  food,  whilst  that  of  the  Stomach  is  increasing;  and  attains  its  lowest 
limit  from  three  to  five  hours  after  a  meal,  frequently  giving  place  to  an  alkaline 
reaction.  The  acidity  then  gradually  increases,  whilst  that  of  the  stomach  is 
decreasing;  and  attains  its  highest  limit  after  a  fast  of  some  hours,  when  the 
stomach  is  quite  empty,  and  its  secretion  neutral.  If  no  food  be  taken,  the 
acidity  does  not  decrease,  but  remains  at  nearly  the  same  point  for  ten  or  twelve 
hours.  When  animal  food  was  alone  employed,  the  diminution  of  the  acidity 
after  a  meal  was  more  marked,  and  continued  longer,  than  when  a  mixed  diet 
was  eaten  (apparently  on  account  of  the  greater  demand  for  acid  in  the  stomach) ; 
and  the  acidity  did  not  rise  quite  so  high  after  fasting,  as  with  a  mixed  diet. 
On  the  other  hand,  when  the  diet  was  purely  vegetable,  the  diminution  of  the 
acidity  of  the  urine  was  never  such  as  to  render  it  absolutely  alkaline,  although 
its  acidity  was  reduced  to  the  point  of  neutrality ;  and  the  increase  of  its  acidity 
after  fasting  was  sometimes  very  considerable,  though  by  no  means  so  marked  as 
the  decrease  of  alkalescence. — These  diurnal  variations  in  the  acidity  of  the  urine 
make  it  highly  probable,  that  corresponding  variations  occur  in  the  alkalescence 
of  the  blood ;  such  diurnal  variations  being  produced  by  the  quantity  of  acid 
separated  from  it,  and  poured  into  the  stomach  for  the  purpose  of  dissolving  the 
food.  The  introduction  of  dilute  sulphuric  acid  into  the  stomach,  even  in  large 

1  "Philosophical  Transactions,"  1851.  —  It  is  right  to  state,  however,  that  this  doctrine 
has  been  called  in  question  by  some  eminent  authorities,  who  deny  the  validity  of  the  test 
for  nitric  acid  employed  by  Dr.  Bence  Jones. 

9  See  Dr.  Golding  Bird  on  "  Urinary  Deposits,"  Am.  Ed. 

8  See  Prof.  Lehmann's  "  Physiological  Chemistry,"  (Cavendish  Society's  Ed.)  vol.  ii. 
pp.  404-406. 

'  "Philos.  Transact.,"  1849. 


THE    KIDNEYS.  —  SECRETION    OF    URINE.  397 

doses,  vas  not  found  to  produce  any  decided  change  in  the  acidity  of  the  urine ; 
the  only  perceptible  effect  being  a  slight  diminution  of  the  decrease  which  takes 
place  after  taking  food,  and  a  slight  augmentation  of  the  increase  after  fasting. 
On  the  other  hand,  the  use  of  liquor  potassae  in  large  doses  lessens  the  acidity 
of  the  urine,  preventing  it  from  rising  after  fasting  to  the  height  it  would  other- 
wise attain,  and  increasing  its  alkalescence  after  a  meal;  but  it  does  not  render 
the  urine  by  any  means  constantly  alkaline,  nor  does  it  hinder  the  variations 
produced  by  the  state  of  the  stomach  from  being  very  evident.  Tartaric  acid  in 
large  doses  temporarily  increases  the  acidity  of  the  urine,  causing  it  to  rise  consi- 
derably higher  than  usual  after  a  fast,  but  not  preventing  that  which  is  passed  a 
few  hours  after  food  from  becoming  alkaline.  Tartrate  of  potash  in  large  doses, 
on  the  other  hand,  has  a  marked  effect  in  rendering  the  urine  alkalescent;  still, 
it  does  not  prevent  the  usual  recurrence  of  the  acidity  some  hours  after  a  meal. 

416.  The  Urine  of  Herbivorous  animals  is  almost  invariably  alkaline;  partly 
because  their  food  contains  a  large  quantity  of  alkaline  and  earthy  bases,  in 
combination  with  citric,  tartaric,  oxalic,  and  other  acids,  which  are  decomposed 
within  the  system ;  and  partly  because  the  amount  of  sulphuric  and  phosphoric 
acids,  generated  as  products  of  the  oxidation  of  the  elements  of  the  tissues  or  of 
the  surplus-food,  is  not  sufficient  to  neutralize  them.     Such  is  the  condition 
which  occasions  the  alkalinity  of  Human   Urine,  when   a  portion  of  the  acid 
which  would  otherwise  show  a  predominance,  is  directed  into  another  channel ; 
and  it  is  exaggerated  in  those  states,  in  which,  either  from  the  irritating  nature 
of  the  food,  or  from  the  irritable  condition  of  the  stomach,  an  undue  quantity 
of  acid  is  poured-out  into  that  viscus;  so  that,  its  reaction  being  habitually  acid, 
that  of  the  urine  becomes  habitually  alkaline.     Such  a  state  of  the  urine  must 
be  carefully  distinguished,  as  Dr.  Bence  Jones  has  pointed-out,'  from  that  in 
which  the  alkalescence  is  due  to  the  presence  of  volatile,  and  not  to  that  of  fixed 
alkali ;  the  difference  being  easily  recognizable  by  the  influence  of  the  liquid 
upon  reddened  litmus-paper,  for  the  restoration  of  its  blue  colour  is  permanent 
in  the  latter  case,  but  only  transitory  in  the  former.     The  alkalescence  due  to 
the  presence  of  volatile  alkali  is  due  to  the  decomposition  of  urea,  whilst  the 
urine  is  yet  within  the  bladder,  through  the  agency  of  morbid  secretions  of  that 
viscus ;  and  it  disappears  when  this  organ  returns  to  its  healthy  state.     On  the 
other  hand,  the  alkalescence  from  fixed  alkali  proceeds  from  disordered  action  of 
the  stomach,  which  is  usually  connected  with  disorder  of  the  general  system; 
and  it  persists  until  this  can  be  remedied.     In  both  forms  of  alkalescence,  there 
is  a  precipitation  of  earthy  phosphates ;  but  in  the  alkalescence  from  fixed  alkali, 
the  precipitate  usually  consists  almost  entirely  of  phosphate  of  rime ;  whilst  in 
that  from  volatile  alkali,  the  amorphous  sediment  of  lime  is  mingled  with  pris- 
matic crystals  of  the  phosphate  of  ammonia  and  magnesia.     These  precipitates 
may  be  obtained  from  healthy  urine,  by  adding  to  it  a  solution  of  potash  or  of 
ammonia;  and  the  decomposition  of  such  urine,  which  begins  to  take  place  very 
soon  after  it  leaves  the  body,  gives  rise  to  the  same  precipitation,  by  the  produc- 
tion of  carbonate  of  ammonia  at  the  expense  of  its  urea. 

417.  A  very  important  series  of  experiments  has  been  performed  by  Prof. 
Lehmann,  with  a  view  to  determine  the  influence  of  diet  upon  the  constitution 
of  the  Urine. — In  the  first  set  of  these  experiments,  he  adopted  an  ordinary 
mixed  diet ;  but  he  took  no  more  solid  or  liquid  aliment,  than  was  needed  to 
appease  hunger  or  thirst,  and  abstained  from  fermented  drinks.     Every  two 
hours  he  took  exercise  in  the  open  air,  but  he  avoided  immoderate  exertion  of 
every  kind.     The  average  result  of  the  examination  of  the  Urine  passed  under 
these  circumstances,  for  fifteen  days,  is  given  in  the  first  line  of  the  subsequent 
table. — In  a  second  set,  Prof.  L.  lived  for  twelve  days  on  an  exclusively  animal 
diet ;  and  for  the  last  six  of  these,  it  consisted  solely  of  eggs.     He  took  32  eggs 
daily;  which  contained  2929  grains  of  dry  albumen,  and  2431  grs.  of  fatty 

1  "Medical  Times,"  Dec.  13,  1851. 


398  OF    SECRETION    AND    EXCRETION. 

matters;  or  about  3532  grs.  of  carbon,  and  465£  grs.  of  azote.  The  amount  of 
Urea  is  shown,  in  the  second  line  of  the  table,  to  have  undergone  a  very  large 
increase ;  and  it  contained  more  than  five-sixths  of  the  whole  azote  ingested. — 
In  a  third  set,  Dr.  L.  lived  for  twelve  days  on  a  vegetable  diet ;  and  its  effect 
upon  the  solid  matter  of  the  Urine  is  shown  in  the  third  line  of  the  table. — In 
a  fourth,  he  lived  for  two  days  upon  an  unazotized  diet,  consisting  entirely  of 
pure  farinaceous  and  oleaginous  substances ;  so  that  the  azotized  matter  of  the 
Urine  must  have  been  solely  the  result  of  the  disintegration  of  the  tissues.  It 
is  seen  to  undergo  a  very  marked  diminution,  under  this  regimen ;  as  is  shown 
in  the  fourth  line  of  the  table.  His  health  was  so  seriously  affected,  however, 
by  this  diet,  that  he  was  unable  to  continue  it  longer. 

Extractive  . 
Solid  Matters.  Urea.  Uric  Add.  Matters  and  Salts. 

I.  Mixed  diet 1047-14  grs.  501-76  grs.  18-26  grs.  196-65  grs. 

II.  Animal  diet 1350-07    "  821-37"  22-82"  112-89    " 

III.  Vegetable  diet 914-66    "  347-10"  15-77"  295-95    " 

IV.  Non-Azotized  diet...  643-53    "  237-90  "  11-34  «  264-48    " 

The  following  inferences  are  drawn  by  Prof.  Lehmann,  from  these  experiments  : — 
1.  Animal  articles  of  diet  augment  the  Solid  matters  of  the  Urine.  Vegetable 
substances,  and  still  more  such  as  are  deprived  of  azote,  on  the  contrary,  dimin- 
ish it. — 2.  Although  Urea  is  a  product  of  the  decomposition  of  the  organism, 
yet  its  proportions  in  the  urine  depend  also  on  the  food,  for  we  find  that  a  richly- 
azotized  diet  considerably  augments  its  quantity.  In  the  above  experiments,  the 
proportion  of  the  Urea  to  the  other  solid  matters  was  as  100  to  116  on  a  mixed 
diet;  as  100  to  63  on  an  animal  diet;  as  100  to  156  on  a  vegetable  diet;  and 
as  100  to  170  on  a  non-azotized  diet. — 3.  The  quantity  of  Uric  acid  depends  less 
on  the  nature  of  the  diet,  than  on  other  circumstances ;  the  differences  observed 
in  it  being  too  slight  to  warrant  our  ascribing  them  solely  to  the  former  cause. — 
4.  The  Protein-compounds,  and  consequently  the  azote  of  the  food,  are  absorbed 
in  the  intestinal  canal ;  and  what  is  not  employed  in  the  formation  of  the  tissues, 
is  thrown-off  by  the  Kidneys  in  the  form  of  Urea  or  Uric  acid ;  these  organs 
being  the  chief,  if  not  the  sole,  channel  through  which  the  system  frees  itself  of 
its  excess  of  azote. — 5.  The  urine  contains  quantities  of  Sulphates  and  Phosphates 
proportional  to  the  azotized  matters  which  have  been  absorbed ;  and  the  propor- 
tion of  these  salts  is  sensibly  increased  under  the  use  of  a  large  amount  of  those 
substances. — 6.  In  the  same  circumstances,  the  Extractive  matters  diminish, 
while  their  quantity  is  increased  by  the  use  of  vegetable  diet ;  a  fact  which 
proves  the  influence  of  vegetable  aliment  over  the  production  of  these  matters 
in  the  urine. — 7.  The  urine  after  the  use  of  animal  food  has  a  strong  acid  reac- 
tion, but  contains  little  or  no  lactic  acid  and  no  hippuric  acid.  Under  a  vege- 
table diet  there  is  more  lactic  acid,  but  it  is  united  to  bases;  and  a  large  proportion 
of  the  free  acid  disappears.1 

418.  Thus,  then,  we  have  seen  that  the  Kidneys  serve  as  the  special  instru- 
ments for  depurating  the  Blood  of  those  highly-azotized  compounds,  which  are 
formed  in  the  system  by  the  decomposition  of  the  materials  of  the  albuminous 
and  gelatinous  tissues,  and  also  by  th§t  of  the  non-assimilated  components  of  the 
food.  We  have  seen  also,  that  they  serve  for  the  removal  of  certain  excremen- 
titious  compounds,  of  which  carbon  is  a  principal  ingredient ;  and  these,  although 
normally  present  in  but  small  amount,  may  undergo  a  marked  increase  in  disease, 
especially  when  the  liver  is  insufficiently  performing  its  functions,  or  the  respi- 
ratory process  is  obstructed.  Further,  we  have  been  led  to  regard  the  Kidneys 
as  the  emunctory,  not  only  for  the  superfluous  water  of  the  blood,  but  also  for 
those  saline  compounds,  which,  having  been  introduced  into  the  system,  or  gene 
rated  within  it,  in  larger  amount  than  is  compatible  with  the  normal  constitution 
of  the  blood,  or  than  is  required  for  the  reparation  of  the  solids  of  the  body,  or 

1  "Physiological  Chemistry"  (Cavendish  Society's  Ed.),  vol.  ii.  pp.  450-452. 


THE  KIDNEYS. — SECRETION  OF  URINE.      399 

for  the  production  of  its  fluid  secretions,  are  only  fitted  for  elimination  (§  216). 
On  this  point  a  very  elaborate  series  of  researches  was  made  by  Wohler,1  who 
showed  that  of  the  soluble  salts  taken  into  the  circulation,  those  are  most  readily 
excreted,  which  produce  a  determination  of  blood  towards  the  kidneys,  whereby 
an  increased  quantity  of  liquid  is  filtered-off  through  the  outlet  which  they 
afford.  This  statement  is  to  be  extended  from  saline  compounds,  to  such  other 
soluble  matters  as  are  not  eliminated  by  preference  through  other  channels,  or 
are  present  in  too  large  an  amount  to  find  their  way  out  thence  with  sufficient 
rapidity.  Thus  we  have  seen  that  when  Sugar  is  injected  into  the  blood  in  suffi- 
cient quantity,  it  appears  in  the  urine  (§  132);  and  the  same  result  may  occur, 
either  from  the  introduction  of  this  substance  in  excessive  amount  by  absorption 
from  the  alimentary  canal,  or  from  the  undue  production  of  it  within  the  system. 
(§  402),  especially  if  at  the  sapae  time  the  process  of  Respiration,  by  which  it  is 
normally  disposed-of  as  fast  as  it  is  formed,  should  be  retarded  or  enfeebled.3 
The  same  may  be  said  of  Lactic  acid,  which  is  not,  any  more  than  Sugar,  a  nor- 
mal constituent  of  the  Urine ;  but  which  not  unfrequently  appears  in  this  excre- 
tion, in  consequence  of  its  being  generated  in  the  system  faster  than  it  can  be 
decomposed  by  oxidation  and  eliminated  by  the  respiratory  process.  In  like 
manner,  too,  the  system  makes  an  effort  to  free  itself  (so  to  speak)  from  various 
substances  altogether  foreign  to  it,  which  have  been  introduced  into  the  circula- 
ting current  by  absorption,  and  which  would  be  injurious  if  retained ;  the  rate 
at  which  it  does  so,  being  in  a  great  degree  dependent  upon  the  functional  acti- 
vity of  the  Kidneys  (§§  223,  224). 

419.  It  is  a  most  important  fact,  in  a  Dietetic  and  Therapeutic  point  of  view, 
that  the  metamorphic  process,  of  which  the  greater  part  of  the  constituents  of 
the  urine  are  the  products,  should  be  capable  of  retardation  or  of  acceleration  by 
the  presence  of  other  substances  in  the  blood.  The  former  appears  to  be  the  opera- 
tion of  theine,  which  is  the  active  principle  of  Tea  and  Coffee  ;  for,  according  to  the 
recent  observations  of  Dr.  Bocker3  upon  the  former,  and  of  Dr.  Julius  Lehmann  4 
(§  65),  upon  the  latter,  a  very  decided  decrease  shows  itself  in  the  amount 
of  urea  and  of  phosphoric  acid  excreted  in  the  urine,  when  those  beverages  are 
employed,  as  compared  with  the  amounts  of  the  same  substances  when  the  gene- 
ral regimen  was  as  nearly  as  possible  identical  in  other  respects,  but  plain  water 
was  substituted  as  a  drink.  The  difference  is  much  greater  in  the  case  of  Coffee 
than  in  that  of  Tea  amounting  generally  to  as  much  as  one-fourth ;  thus  : — 

Urea.  Phosphoric  acid.  Common  salt. 
grammes.  grammes.  grammes. 

H.  S.,  without  coffee,  voided 31-298  4-421  9-865 

"      with  coffee  from  1    oz.  of  beans 21-888  3-001  8-819 


Difference 9-410  1-420  1-046 

It  appeared  from  other  experiments,  that  neither  caffeine  nor  the  empyreumatio 
oil,  separately  administered,  produce  the  same  effect  as  coffee  itself.     Hence  it 

1  "  Miiller's  Elements  of  Physiology,"  translated  by  Baly,  p.  589. 

a  It  must  be  confessed  that  the  rationale  of  the  remarkable  fact  first  discovered  by  M. 
Claude  Bernard  ("Gazette  MeMicale,"  Juin  2,  1849), — that  irritation  of  the  floor  of  the 
fourth  ventricle,  by  puncture  or  by  a  slight  galvanic  shock,  causes  the  urine  to  become 
saccharine,  whilst  a  more  severe  lesion  checks  the  elimination  of  sugar,  apparently  by 
stopping  its  production, — has  not  yet  been  fully  made-out.  Nevertheless,  the  statement 
in  the  text  may  probably  be  accepted  as  representing  a  part  of  the  truth  upon  this  curious 
subject.  (See  Ileynoso  in  "  Comptes  Rendus,"  torn,  xxxiii,  xxxiv;  Michea,  op.  cit.,  torn, 
xxxiii.  ;  Dechambre  in  "Gazette  Medicale,"  1852,  No.  14:  Dr.  L.  Beale  in  "Brit,  and 
For.  Med.-Chir.  Rev.,"  vol.  xi.  p.  106;  and  Prof.  Lehmann  in  his  "  Physiologischeu 
ChSmie,"  2nd  edit,  band  ii.,  pp.  217,  375. 

3  "  Archiv.  des  Vereins  fur  gemeinschaftlichen  Arbeiten  zur   Forderung  der  Wisseu- 
schaftlichen  Heilkunde,"  1854. 

4  "Annalen  der  Chem.  und  Pharm."  band.  Ixxxvii. 


400  OF    SECRETION    AND    EXCRETION. 

appears  that  the  use  of  Tea  or  Coffee,  by  retarding  the  '  waste '  of  the  system, 
diminishes  the  demand  for  food,  and  makes  a  limited  amount  of  it  go  further; 
and  this  conclusion  seems  fully  borne  out  by  experience. — The  like  results  hap- 
pen, according  to  Dr.  Bocker,1  under  the  use  of  small  quantities  of  Alcohol  fre- 
quently repeated;  as  much  as  13£  grammes  less  urea  being  excreted  daily,  when 
a  tea-spoonful  of  proof-spirit  was  taken  seven  or  eight  times  a  day,  than  when 
water  alone  was  drank.  It  does  not  hence  follow,  however,  that  Alcohol  can  be 
used  as  advantageously  for  this  purpose  as  Tea  or  Coffee ;  in  fact,  it  may  be 
doubted  whether  it  is  so  much  by  diminishing  the  '  waste '  of  matter,  as  by 
interfering  with  the  due  elimination  of  its  products,  that  Alcohol  occasions  a 
diminution  in  the  weight  of  the  urinary  solids.  For,  as  we  have  seen  (§  316  vi.), 
it  interposes  a  marked  obstruction  to  the  due  oxidation  of  the  excrementitious 
matter,  which  has  been  received  back  into  the  blood  for  the  purpose  of  elimina- 
tion, and  to  the  removal  of  the  hydro-carbonaceous  portion  of  it;  and  further, 
very  cogent  evidence  is  supplied  by  the  experience  of  Zymotic  diseases,  that  the 
very  same  produces  an  accumulation  of  fermentable  azotized  substances  in  the 
blood  (§  65). — It  seems  not  unlikely  that  the  almost  instinctive  craving  for  To- 
bacco among  a  large  proportion  of  mankind,  arises  out  of  its  possession  of  a  power 
of  retarding  the  metamorphosis  of  the  tissues ;  since  we  find  that  men,  when  sup- 
plied with  this  article,  can  far  better  sustain  being  put  upon  a  short  allowance 
of  food,  than  when  destitute  of  it. 

420.  Of  the  substances  that  accelerate  the  metamorphosis  of  the  tissues,  and 
thus  augment  the  solids  of  the  urine,  the  Alkalies  and  their  carbonates  are  those 
whose  action  is  best  known;  these  (with  such  of  their  salts  as  are  formed  by 
acids  which  are  decomposed  in  the  blood  into  the  carbonic,  such  as  the  acetates, 
tartrates,  and  citrates),  have  a  powerful  solvent  action  on  the  albuminous  com- 
pounds generally,  and  tend  to  break-up  these  compounds  into  simpler  forms  of 
combination.  Hence  it  seems  likely  that  their  presence  in  the  Blood  in  increased 
amount,  will  tend  to  hasten  the  retrograde  metamorphosis  of  the  tissues ;  their 
chemical  force  being  exerted,  not  merely  upon  those  which  are  already  in  a  state 
of  disintegration,  but  also  upon  those,  which,  being  disposed  to  degenerate,  cannot 
exercise  that  resisting  power,  which  they  possess  when  in  a  state  of  complete 
vital  activity.  The  operation  of  Liquor  Potassse  in  health,  in  acute  rheumatism, 
and  in  chronic  diseases,  has  been  carefully  studied  by  Dr.  Parkes  ;2  and  he  has 
given  satisfactory  evidence  that  it  causes  an  increase  in  the  solids  of  the  urine 
generally,  but  especially  in  the  urea  and  in  the  amount  of  the  sulphuric  and 
phosphoric  acids ;  thus  clearly  showing  that  it  hastens  the  metamorphosis  of 
some  of  the  albuminous  structures  of  the  body.  The  increase  was  more  marked, 
as  might  be  expected  from  what  has  just  been  stated,  in  the  cases  of  chronic  dis- 
ease, than  in  ordinary  health.  The  following  comparative  tables  show  the  rela- 
tive amounts  before,  during,  and  after,  the  employment  of  liquor  potassse,  in  (i.) 
a  case  of  chronic  Eczema,  and  (11.)  a  case  of  chronic  Phthisis : 

Sulphuric  Phosphoric 

I.                                                   Solids.  Urea.  Acid.  Acid. 

Before  Liq.  Pot .'.660-1  371-5  29-2  10.6 

During 689-6  454-5  33-5  15.4 

After 527-2  372-8  29-0  10-9 

II. 

Before  Liq.  Pot 608-2  368-8  18-6  9-9 

During 781-7  408-8  20-9  14-5 

After 643-9  271-5  16-9  9-7 

A  similar  Table  has  been  given  by  Dr.  Golding  Bird,3  of  the  entire  constituents 
of  the  secretion  passed  during  24  hours,  before  and  after  the  administration  of 
three  drachms  of  acetate  of  potash  : — 

1  Op.  cit.  1853  a  "Brit,  and  For.  Med.-Chir.  Review,"  vols.  xi.,  xiii.  xiv. 

"  See  his  '  Lectures  on  the  Influence  of  Researches  in  Organic  Chemistry  on  Therapeu- 
tics,' in  "  Medical  Gazette,"  1848,  vol.  xlii.  p.  230 


OF  THE  SKIN; — CUTANEOUS  TRANSPIRATION.      401 

Before  Medicine.  After  Medicine 

Quantity  of  Urine fl  ^  xvi.  fl  %  xlvi. 

Specific  Gravity 1-025  1-017 

Total  Solids 416  grs.  782  grs. 


Uric  Acid 2-6  grs.  5-5 

Urea 130-5    "  202-4 

Other  Organic  Compounds 189-3    "  295-5 

Soluble  Salts 72-0    "  248-4 

Insoluble  Salts 21-6    "  32-2 

The  increase  (1764  grains)  in  the  quantity  of '  soluble  salts/  is  to  be  chiefly  set- 
down  to  the  account  of  the  medicine  taken-in ;  but  the  whole  remainder  of  the 
augmentation  seems  fairly  attributable  to  the  increased  metamorphosis.  A  cer- 
tain degree  of  such  increase  is  producible  by  the  simple  ingestion  of  a  large 
amount  of  Water;1  so  that  this  is  by  no  means  so  inoperative  as  it  might  at  first 
sight  appear,  in  cleansing  and  purifying  (so  to  speak)  the  penetralia  of  the  sys- 
tem.— It  does  not  appear,  however,  that  the  excretion  of  the  urinary  solids  is  aug- 
mented by  those  l  diuretic'  medicines,  which  cause  a  larger  amount  of  liquid  to 
be  passed-off  through  the  Kidneys,  merely  by  determining  an  increased  flow  of 
blood  to  them.  On  the  contrary,  it  would  seem  as  if,  by  producing  congestion 
and  irritation,  they  sometimes  interfered  with  the  normal  process  of  secretion ; 
so  that  the  quantity  of  solid  constituents  is  actually  decreased,  notwithstanding 
the  large  augmentation  in  the  watery  part  of  the  urine.  This  very  important  fact 
has  been  demonstrated  by  Prof.  Krahmer,*  who  gives  the  following  as  the  result 
of  his  observations  upon  the  amounts  excreted  in  24  hours,  after  the  administra- 
tion of  diuretics  to  persons  in  health  : — 

Total  Solids  Organic  Inorganic 

Medicine  given.  in  Urine.  Compounds.  Compounds. 

None 2-40oz.  l-28oz.  1  13  oz. 


Juniper 2-12 

Venice  Turpentine 1-94 

Squill 2-25 

Digitalis 2-45 

Guiacum 2-43 

Colchicurn  . ..  ..   2-32 


0-94 
1-11 
1-04 

1-28 
1-38 
1-36 


1  18  " 
083  « 
1-21  « 
1-17  " 
1-05  " 
0-96  « 


Similar  results  have  been  obtained  by  Dr.  Golding  Bird. — It  seems  highly  pro- 
bable that  the  '  critical  evacuations'  of  urine,  as  of  sweat,  or  faecal  matter,  on 
which  the  older  physicians  were  accustomed  to  lay  great  stress,  are  really  charged 
with  noxious  substances,  of  which  the  blood  is  thus  depurated ;  and  that  great 
benefit  would  frequently  arise  in  practice  from  the  use  of  the  'alterative  diuretics/ 
as  suggested  by  Dr.  Gr.  Bird,  where  (as  in  chronic  rheumatism,  gout,  &c.,)  there 
is  reason  to  believe  that  a  quantity  of  mal-assimilated  matter  exists  in  the  system, 
of  which  it  is  important  to  get-rid.  In  many  such  cases,  indeed,  clinical  observa- 
tion had  already  established  the  benefit  derivable  from  such  medicines,  without 
affording  the  rationale  of  it. 

4. —  Of  the  Skin  ; —  Cutaneous  Transpiration. 

421.  The  Skin  is  the  seat  of  various  secretions, — as  the  Sebaceous,  Ceruminous, 
and  Odoriferous, — for  each  of  which  it  is  provided  with  special  organs  (PRINC. 
OF  GEN.  PHYS.,  Am.  Ed.);  but  these  have  reference  chiefly  to  its  own  protection, 
or  to  some  other  local  purpose ;  and  the  only  one  which  can  be  regarded  as  truly 
excrementitious,  is  the  Transpiration  of  aqueous  fluid,  holding  certain  matters  in 
solution.  The  elimination  of  this  fluid  from  the  blood  is  effected  by  the  Siirfo 
riparous  glandulae  (Fig.  118),  which  essentially  consist  of  long  convoluted  tubes 

1  See  Dr.  Bockers,  in  "  Zeitschrift  der  K  K  Gesellschaft  der  Alltze  zu  Wien,"  April, 
1851. 

•  "  Heller's  Archiv./'  Dec.  1847. 
26 


OF    SECRETION    AND    EXCRETION. 

(1,  1)  rarely  single,  but  usually  multiplied  by  repeated  dichotomous  subdivision 

(2),  sometimes  also  giving-off  short  caecal  pro- 
cesses before  their  termination.  These  are 
seated  rather  beneath  the  Corium,  in  the  midst 
of  the  subcutaneous  adipose  tissue,  than  in  the 
substance  of  the  skin  itself.  All  the  tubuli  of 
each  gland  unite  so  as  to  form  but  one  duct ;  and 
this  passes  upwards  through  the  Cutis  and  Cu- 
ticle, in  a  somewhat  corkscrew-like  manner  (3), 
to  open  upon  the  surface  of  the  latter  (4),  which 
it  usually  reaches  obliquely,  so  that  the  outer 
layer  of  the  Epidermis  forms  a  sort  of  little  valve, 
which  is  lifted  by  the  secreted  fluid  as  it 
issues-forth.  These  glandulae  are  diffused  in 
varying  proportions  over  the  entire  surface  of 
the  body.  According  to  Mr.  Erasmus  Wilson,' 
as  many  as  3528  of  them  exist  in  a  square  inch 
of  surface  on  the  palm  of  the  hand;  and  since 
every  tube,  when  straightened-out,  is  about  a 
quarter  of  an  inch  in  length,  it  follows  that,  in  a 
square  inch  of  skin  from  the  palm  of  the  hand, 
there  exists  a  length  of  tube  equal  to  882  inches, 
or  73  J  feet.  The  number  of  glandulae  in  other 
parts  of  the  Skin  is  sometimes  greater,  but  is  ge- 
nerally less  than  this;  and,  according  to  Mr. 
Wilson,  about  2800  may  be  taken  as  the  average 
number  of  pores  in  each  square  inch  throughout 
the  body.  Now  the  number  of  square  inches  of 
surface,  in  a  man  of  ordinary  stature,  is  about 
2500 ;  the  total  number  of  pores,  therefore,  may 
be  about  seven  millions;  and  the  length  of  the 
perspiratory  tubing  would  thus  be  1,570,000 
inches,  or  145,833  feet,  or  48,611  yards,  or 
nearly  28  miles. 

422.  Although  a  separation  of  fluid  by  this 
extensive  glandular  apparatus  is  continually  tak- 
ing-place, yet  this  fluid,  being  usually  carried-off 
in  the  form  of  vapour  as  fast  as  it  is  separated, 
does  not  ordinarily  accumulate  so  as  to  become 
sensible.  If,  however,  from  the  increased  amount 
of  the  secretion,  or  from  the  condition  of  the  sur- 
rounding air,  the  whole  fluid  thus  poured-out 


Sudoriparous  Gland  from  the  palm 
of  the  hand,  magnified  40  diam.  j — ], 
1.  contorted  tubes,  composing  tho 
•  gland,  and  uniting  in  two  excretory 
ducts,  2,  2,  which  unite  into  one  spi- 
ral canal  that  perforates  the  epider- 
mis at  3,  and  opens  on  its  surface  at 
4  ;  the  gland  is  imbedded  in  fat-vesi- 
cles, which  are  seen  at  5,  5. 


should  not  evaporate,  the  residue  forms  minute 


drops  upon  the  surface  of  the  skin.  Thus  the 
Sudoriparous  excretion  may  take  the  form  either 
of  sensible  or  of  insensible  transpiration ;  the  lat- 
ter being  constant,  the  former  occasional.  It  is 
difficult  to  obtain  enough  of  this  secretion  for  analysis,  free  from  the  sebaceous 
matters,  epidermic  scales,  &c.,  which  accumulate  on  the  surface  of  the  skin;  and 
its  character  can  only,  therefore,  be  stated  approximately.  It  usually  shows  an 
acid  reaction,  which  seems  due  to  the  presence  of  acetic  acid;  and  to  this,  or  to 
lactic  acid,  we  are  probably  to  attribute  the  sour  smell  which  it  has,  especially  in 
some  disordered  states  of  the  system.  The  proportion  of  solid  matter  contained 
in  different  specimens  differs  very  greatly;  thus,  according  to  Anselmino,  it  varies 
between  5  and  12-5  parts  in  1000;  the  recent  observations  of  Favre2  give  4-43 
1  "  On  the  Manngement  of  the  Skin,"  2d  Am.  Ed.,  p.  62. 
1  "  Archiv.  G6ner.  de  MeU,"  1853,  5i6me  Se>.,  torn,  ii.,  pp.  1-12. 


OF  THE  SKIN; — CUTANEOUS  TRANSPIRATION.     403 

parts  per  1000  as  the  proportion  contained  in  nearly  nine  gallons  which  he  had 
collected;  whilst  those  of  Schottin1  raise  it  as  high  as  224 
parts  per  1000,  of  which,  however,  12  parts  consist  of  epithe-  FlG* 
lium  and  insoluble  matters.  The  greater  part  of  it  consists  ot 
organic  matter,  the  larger  proportion  of  which  appears  to  be  a 
protein-compound  in  a  state  of  incipient  decomposition ;  urea, 
however,  has  been  detected  in  this  product  by  Dr.  Landerer;2 
and  his  observations  are  confirmed  by  Favre  (loc.  cit.),  who 
considers  that  it  is  upon  the  presence  of  this  or  a  similar  sub- 
stance, that  the  readiness  with  which  the  fluid  becomes  alkaline 
depends.  Schottin,  however,  failed  in  detecting  urea  in  normal 
sweat;  but  he  remarked  that  in  uraemia,  especially  when  oc-  The  lining  mem- 
currine:  in  cases  of  cholera,  considerable  quantities  of  this  sub-  branj '  or  she^th>  of 

.      ..^  one  of  the  perspiratory 

stance  pass  into  the  cutaneous  transpiration,  so  as  even  to  form  tu^,eSi  Magnified  250 
a  thin  bluish  pulverulent  layer  on  the  dead  body.  The  re-  diameters. 
mainder  consists  of  saline  compounds ;  of  which  the  chlorides 
of  potassium  and  sodium  appear  to  be  pretty  constantly  present;  whilst  muriate  of 
ammonia,  alkaline  phosphates,  free  acetic  and  butyric  acids,  and  acetate  of  soda, 
have  also  been  said  to  occur  in  it.  The  presence  of  lactic  acid  is  affirmed  by  Favre, 
and  denied  by  Schottin ;  the  former  observer  also  affirms  that  he  has  discovered  a 
new  nitrogenous  acid  in  this  excretion,  to  which  he  has  given  the  name  of  hydrotic 
or  sudoric  acid.  —  The  proportion  of  solid  ingredients  would  probably  be  found 
larger  in  the  true  secretion  of  the  Sudoriparous  glands,  if  we  had  the  means  of  col- 
lecting it  separately ;  for  of  the  whole  fluid  which  passes-off  from  the  surface  of 
the  skin,  only  a  portion  can  be  properly  said  to  be  secreted  by  these  glands,  a  large 
part,  as  in  the  case  of  the  Kidneys,  being  apparently  the  product  of  simple  trans- 
udation  (§  406).  It  will  be  this  part  which  will  undergo  augmentation,  when  a 
special  determination  of  blood  to  the  skin  is  produced  by  external  heat ;  and 
there  is  no  more  reason  to  think  that  an  increase  in  the  amount  of  solid  matter 
thus  excreted  is  induced  by  such  agency,  than  that  an  increase  in  the  solids  of 
the  urine  can  be  determined  by  ordinary  diuretics  (§  420).  Hence  the  debili- 
tating effects  commonly  assigned  to  profuse  perspirations,  must  be  attributed  to 
some  other  causes ;  and  these  it  does  not  seem  very  difficult  to  find.  Thus,  the 
great  fatigue  which  is  experienced  as  a  consequence  of  muscular  exertion  in  a 
heated  atmosphere,  may  fairly  be  set-down  to  the  diminished  activity  of  the  res- 
piratory process  at  high  temperatures  (§  316, 1.);  and  the  ' colliquative  sweating' 
of  hectic  fever  is  obviously  not  a  cause,  but  a  consequence,  of  the  debilitated 
state  of  the  general  system. 

423.  The  entire  amount  of  fluid  which  is  'insensibly'  lost  from  the  Cutaneous 
and  Pulmonary  surfaces,  is  estimated  by  Seguin  at  18  grains  per  minute;  of 
which  11  grains  pass-off  by  the  skin,  and  7  by  the  lungs.  The  maximum  loss 
by  Exhalation,  cutaneous  and  pulmonary,  during  twenty-four  hours,  (except 
under  very  peculiar  circumstances,)  is  5  Ibs. ;  the  minimum  If  Ib.  It  varies 
greatly,  according  to  the  condition  of  the  atmosphere,  and  that  of  the  body  itself; 
and  these  variations,  as  we  shall  hereafter  see  (§  444),  have  a  most  important 
share  in  the  regulation  of  the  temperature  of  the  body.  The  whole  amount  of 
Cutaneous  transpiration,  '  sensible '  and  '  insensible/  is  greatly  increased  by  heat 
and  dryness  of  the  surrounding  air ;  for  the  heat  occasions  the  determination  of 
an  augmented  amount  of  blood  to  the  cutaneous  vessels ;  and  of  the  fluid  which 
thus  transudes,  a  large  portion  is  carried-off  in  the  state  of  vapour.  The  more 
the  heated  atmosphere  is  already  charged  with  watery  vapour,  the  smaller  will  be 
the  proportion  of  the  transuded  fluid  that  will  thus  'insensibly'  pass  away;  and 
the  more  will  accumulate  as  '  sensible  '  perspiration.  Exact  observations  on  thi.s 

1  "Arch,  fur  physiol.  Heilkunde,"  band  ii.  pp.  73-104. 
3  "  Heller's  Archiv.,"  band  iv.  p.  196. 


£04  OF    SECRETION    AND    EXCRETION. 

point,  however,  are  much  wanting,  in  which  not  merely  the  temperature,  but  the 
hygrometric  state  of  the  air  should  be  precisely  determined ;  the  best  hitherto 
recorded  being  those  made  by  Dr.  Southwood  Smith  '  at  the  Phoenix  Gas  Works, 
in  which  the  former  element  only  was  carefully  noted.  These  observations  were 
made  upon  eight  of  the  workmen  employed  in  'drawing'  and  'charging'  the 
retorts  and  in  making-up  the  fires,  during  which  they  were  exposed  to  intense 
heat;  the  men  were  accurately  weighed  in  their  clothes,  immediately  before  they 
began,  and  after  they  had  finished  their  work ;  and  in  the  interval  between  the 
first  and  second  weighings,  they  were  not  allowed  to  partake  of  any  solid  or  liquid 
ingesta,  nor  to  part  with  urine  or  fasces. 

Experiment  I.  Nov.  18,  1836.  Day  bright  and  clear.  Temperature  of  the 
air  in  which  the  men  worked,  60°  Fahr.  Barometer  29-25  in.  to  294  in. 
Duration  of  labour,  45  minutes. — Average  loss  of  weight,  3  Ibs.  6  oz.  ;  maximum, 
4  Ibs.  3  oz. ;  minimum,  2  Ibs.  8  oz. 

Experiment  II.  Nov.  25,  1836.  Day  foggy  with  scarcely  any  wind.  Tem- 
perature of  tne  air,  39°  Fahr.  Barometer  29-8.  Duration  of  labour,  75  minutes. 
Average  loss  of  weight,  2  Ibs.  2  oz. ;  maximum,  2  Ibs.  15  oz.  ;  minimum,  14  oz. 

Experiment  III.  June  3,  1837.  Day  exceedingly  bright  and  clear,  with 
little  wind.  Temperature  of  the  air,  60°.  Duration  of  labour,  60  minutes. — 
Average  loss  of  weight,  2  Ibs.  8  oz. ;  maximum,  3  Ibs.  ;  minimum,  2  Ibs. 

Experiment  IV.  On  the  same  day,  two  other  men  worked  in  an  unusually 
hot  place  for  70  minutes;  the  loss  of  weight  of  one  of  these  was  4  Ibs.  14  oz. ; 
and  of  the  other  5  Ibs.  2  oz. 

Although  the  individuals  subjected  to  these  experiments  were  not  in  all  in- 
stances the  same,  yet  there  was  enough  of  identity  among  them,  to  admit  of  the 
certain  inference,  that  the  amount  of  fluid  lost  must  be  influenced  by  the  state 
of  the  individual  system,  as  well  as  by  that  of  the  surrounding  medium.  Thus 
in  the  second  experiment,  Michael  Griffiths  lost  2  Ibs.  6  oz.,  and  Charles  Cahell 
2  Ibs.  15  oz. ;  whilst  in  the  third,  Michael  Griffiths  lost  3  Ibs.,  and  Charles  Cahell 
only  2  Ibs.  It  is  probable  that  the  amount  of  liquid  ingested  not  long  previously, 
might  have  a  considerable  influence  on  the  quantity  lost  by  transpiration  under 
such  circumstances. 

424.  The  Cutaneous  excretion,  as  already  pointed-out,  is  in  great  degree  vica- 
rious with  the  Urinary,  in  regard  to  the  amount  of  fluid  eliminated ;  the  urine 
being  more  watery  in  proportion  as  the  cutaneous  exhalation  is  diminished  in 
amount,  and  vice  versd  (§  406).  But  we  are  also  to  look  at  these  two  excre- 
tions as  vicarious,  in  regard  to  the  elimination  of  the  products  of  the  '  waste '  of 
the  system.  The  share  which  the  Skin  has  in  this  office  has  probably  been  gene- 
rally under-rated.  There  is  reason  to  believe  that  at  least  100  grains  of  azotized 
matter  are  excreted  from  it  daily;  and  any  cause  which  checks  this  excretion, 
must  throw  additional  labour  on  the  kidneys,  and  will  be  likely  to  produce  dis- 
order of  tneir  function. — The  secreting  action  of  the  Skin  is  influenced  by  gene- 
ral conditions  of  the  vascular  and  nervous  systems;  which  are  as  yet  ill  under- 
stood. It  is  quite  certain,  however,  that  through  the  influence  of  the  latter  the 
secretion  may  be  excited  or  suspended ;  this  is  seen  on  the  one  hand  in  the  state 
of  syncope,  and  in  the  effects  of  depressing  emotions,  especially  fear,  and  its  more 
aggravated  condition,  terror;  and  on  the  other,  in  the  dry  condition  of  the  skin 
during  states  of  high  nervous  excitement.  It  is  very  probable  that,  in  many 
forms  of  fever,  the  suppression  of  the  perspiration  is  a  cause,  rather  than  an 
effect,  of  disordered  vascular  action  ;  for  there  are  several  morbid  conditions  of 
large  parts  of  the  surface,  in  which  the  suppression  of  the  transpiration  appears  to 
be  one  of  the  chief  sources  of  danger,  having  a  tendency  to  produce  congestion 
and  inflammation  of  internal  organs.  From  the  experiments  of  Dr.  Fourcault,  it 
appears  that  complete  suppression  of  the  perspiration  in  animals,  by  means  of  a 
varnish  applied  over  the  skin,  gives  rise  to  a  state  termed  by  him  '  cutaneous 
1  "  Philosophy  of  Health,"  vol.  ii.  pp.  391-396. 


GENERAL    CONSIDERATIONS.  405 

asphyxia;'  which  is  marked  by  imperfect  arterialization  of  the  blood,  and  con- 
siderable fall  of  temperature  (§  436) ;  and  which,  as  it  produces  death  in  the 
lower  animals,  would  probably  do  the  same  in  Man.  A  partial  suppression  by 
the  same  means  gives  rise  to  febrile  symptoms,  and  to  albuminuria.1 — There  can 
be  no  doubt  whatever,  that  imperfect  action  of  the  Cutaneous  glandulae,  conse- . 
quent  upon  inactive  habits  of  life  and  want  of  ablution,  is  a  very  frequent  source 
of  disorder  of  the  general  system ;  occasioning  the  accumulation  of  that  decom- 
posing organic  matter  in  the  blood,  which  it  is  the  special  office  of  these  glandulse 
to  eliminate.  Hence  the  due  maintenance  of  health  requires  that  this  excretion 
should  be  promoted  by  the  use  of  the  natural  and  appropriate  means  just  re- 
ferred-to;  and  this  is  the  more  necessary,  when  from  any  cause  the  function  of 
the  kidneys  is  imperfectly  performed  There  are  many  diseased  states,  moreover, 
in  which  there  appears  to  be  a  special  determination  of  the  materies  inorbi  to 
the  Skin,  arid  in  which,  therefore,  the  use  of  means  that  promote  the  cutaneous 
excretion  constitutes  the  most  efficient  method  of  eliminating  it  from  the  blood.2 


CHAPTER  X. 

EVOLUTION   OF   HEAT,    LIGHT,   AND   ELECTRICITY. 

1. —  General  Considerations. 

425.  THE  series  of  Nutritive  operations  which  has  now  been  passed  in  review, 
has  been  shown  to  consist  in  the  continual  appropriation,  by  the  Animal  organ- 
ism, of  certain  'organic  compounds'  or  ' alimentary  materials/  which  have  been 
generated  for  its  use  by  Plants;  and  in  the  constant  restoration  of  their  elements 
to  the  Inorganic  world,  either  in  the  very  same  forms  of  combination  in  which 
they  originally  existed  there,  or  as  products  of  incipient  decay,  by  whose  further 
decomposition  those  simple  binary  compounds  will  be  reproduced.  And  thus,  so 
far  as  the  material  components  of  the  Organic  Creation  are  concerned,  the  agency 
of  Vegetable  life  is  concerned  in  withdrawing  them  from  the  Mineral  world,  and 
that  of  Animal  life  in  returning  them  to  it,  after  they  have  served  their  purpose 
in  the  living  structure.  But  if  we  examine  into  the  source  of  those  active 
powers  or  '  forces/  on  whose  operation  every  change,  no  less  in  the  organized 
body,  than  in  what  is  commonly  designated  as  'inert'  matter,  is  dependent,  we 
shall  find  that  they  are  all  traceable  to  the  solar  radiations.  It  is  by  the  action 
of  the  Light  and  Heat  of  the  Sun  upon  the  Vegetable  germ,  that  it  is  enabled 
to  exercise  its  wonderful  transforming  capacity,  whereby  it  extracts  carbon,  hydro- 
gen, nitrogen,  and  oxygen,  from  the  carbonic  acid,  water,  and  ammonia  furnished 
by  the  atmosphere  or  the  soil ;  and  that  it  converts  these  into  the  albuminous, 
saccharine,  and  oleaginous  compounds,  which  are  the  destined  food  of  Animals. 
And  it  is  under  the  influence  of  Heat  chiefly  derived  from  the  same  source,  that 
the  greater  number  of  tribes  of  Animals  are  enabled  to  apply  these  compounds  to 
the  purposes  of  organization ;  and  that,  through  the  peculiar  instruments  thus 

1  See  his  important  Treatise,  "Causes  Ge'ne'rales  des  Maladies  Chroniques,"  &c.,  1844; 
and  "  Brit,  and  For.  Med.  Rev.,"  vol.  xx.  pp.  106-108. 

3  The  practical  value  of  active  diaphoresis  in  many  febrile  diseases,  is  well  understood 
by  the  native  practitioners  among  the  Negroes  of  the  Guinea  Coast;  who,  according  to 
Dr.  Daniell  ("Medical  Topography  and  Native  Diseases  of  the  Gulf  of  Guinea,"  pp.  119- 
20)  make  use  of  it  most  successfully  in  the  treatment  of  adynamic  remittent  fevers.  Dr. 
Daniell  states  that  having  himself  had  abundant  experience  of  its  efficacy,  he  has  no  doubt 
of  its  superiority  in  these  cases  to  the  ordinary  practice  of  venesection,  saline  purgatives, 
large  doses  of  calomel,  &c.  And  he  has  repeatedly  stated  that  one  great  secret  of  pre- 
serving health  in  tropical  climates,  lies  in  the  attention  to  the  cutaneous  functions. 


406  EVOLUTION    OF   HEAT,   LIGHT,    AND    ELECTRICITY. 

constructed,  those  various  kinds  of  Vital  Force  are  evolved,  whose  operations  are 
so  different  from  any  which  we  witness  in  the  Inorganic  world.  Accordingly  we 
observe  that  the  'rate  of  life'  in  this  larger  proportion,  of  the  Animal  kingdom, 
is  regulated,  as  in  Plants,  by  the  amount  of  Heat  supplied  to  the  organism  from 
external  sources ',  and  that,  when  the  external  temperature  is  reduced  below  a 
certain  point,  there  is  an  entire  cessation  of  all  vital  activity.1  But  there  are  cer- 
tain tribes,  especially  Birds  and  Mammals,  which  possess  the  power  of  generating 
Heat  within  themselves,  to  such  a  degree  as  to  render  the  rate  of  their  vital  pro- 
cesses almost  entirely  independent  of  external  influences ;  and  there  is  probably 
no  one  species  that  can  exercise  this  power  more  effectually,  and  through  a 
greater  range  of  external  conditions,  than  Man  is  able  to  do.  Of  this  we  shall 
presently  have  evidence. — The  evolution  of  Light,  again,  is  by  no  means  an 
unusual  phenomenon  among  the  lower  tribes  of  animals  ;  but  where  it  does  occur, 
it  usually  appears  to  have  some  special  purpose,  as  is  obvious  enough  in  the  case 
of  the  glow-worm  and  other  luminous  Insects.  But  the  luminosity  which  is 
occasionally  exhibited  in  Man  (§  445),  must  be  regarded  as  an  altogether  abnor- 
mal phenomenon,  whose  physiological  interest  arises  out  of  the  peculiarity  of  the 
circumstances  under  which  it  presents  itself. — Of  the  degree  in  which  Electricity 
is  generated  in  the  living  body,  we  know  comparatively  little.  There  is  strong 
evidence  that  a  disturbance  of  Electric  polarity  must  take  place  in  every  action  of 
Organic  as  well  as  of  Inorganic  Chemistry  ;  and  thus  that  every  molecular  change 
in  the  Animal  as  well  as  in  the  Vegetable  organism  must  involve  an  alteration  in 
its  electric  condition.  But  it  would  seem  that  in  the  Animal  body  generally, 
these  alterations  are  made  to  balance  each  other  so  exactly,  that  no  considerable 
disturbance  of  the  electric  equilibrium  ordinarily  takes  place  in  the  organism  as 
a  whole ;  and  it  is  only  in  certain  peculiar  cases  (as  in  the  Electric  Fishes)  that 
a  provision  exists  for  the  generation  of  Electricity  in  considerable  amount  and 
intensity,  with  a  view  to  some  special  purpose.  In  the  Human  subject,  however, 
an  extraordinary  production  of  free  Electricity,  as  of  Light,  occasionally  presents 
itself;  and  this,  taken  in  connection  with  other  evidence,  would  seem  rather  to 
indicate  a  departure  from  the  balance  usually  maintained  between  the  opposite 
electrical  changes  continually  taking  place,  than  to  be  due  to  the  introduction  of 
any  extraordinary  sources  of  electric  disturbance  (§  446). 

2. — Evolution  of  Heat. 

426.  All  the  vital  actions  of  the  body  of  Man,  as  of  that  of '  warm-blooded' 
animals  generally,  require  an  elevated  temperature  as  a  condition  of  their  per- 
formance ;  and  the  high  degree  of  constancy  and  regularity  which  is  observable 
in  these  actions,  appears  to  depend  in  great  degree  upon  the  provision  which  the 
organism  contains  within  itself,  for  the  maintenance  of  that  temperature  at  a  fixed 
standard.  This  constancy  and  regularity  are  most  remarkably  exhibited  in  the 
various  periodical  changes  to  which  the  body  is  subject  both  in  health  and  in 
disease;  the  uniformity  of  whose  recurrence  is  due  to  a  corresponding  uniformity 
in  the  rate  of  vital  action  taking  place  in  the  interval.  Thus,  as  will  be  shown 
hereafter,  the  period  of  parturition  is  in  great  degree  determined  by  the  matura- 
tion of  the  foetal  structures;  and  the  uniformity  of  the  time  which  this  requires 
(like  the  corresponding  uniformity  in  the  period  of  development  in  the  embryo- 
bird)  may  be  fairly  attributed  to  the  regularity  of  the  supply  of  Heat,  which  is 
the  power  that  especially  determines  the  formative  operations.  For  the  periods 
of  all  similar  phenomena  in  '  cold-blooded '  animals,  which  have  no  power  of 
maintaining  an  independent  temperature,  exhibit  no  such  uniformity;  being  en- 
tirely dependent  (as  in  Plants)  upon  the  degree  of  external  warmth  to  which 
their  bodies  are  subjected. — We  shall  now  inquire,  in  the  first  place,  into  the 

1  See  "  Principles  of  General  Physiology,"  Am.  Ed. 


EVOLUTION    OF    HEAT. 


407 


amount  of  Heat  thus  generated  by  Man ;   and  then   into  the  sources  of  its 
production. 

427.   Our  present  knowledge  of  the  ordinary  Temperature  of  the  Human  body 
under  different  circumstances,  is  chiefly  due  to  the  investigations  of  Dr.  J.  Davy.1 
— The  first  series  of  his  observations  included  114  individuals  of  both  sexes,  of 
different  ages,  and  among  various  races,  in  different  latitudes,  and  under  various 
temperatures ;  the  external  temperature,  however,  was  in  no  instance  very  low, 
and  the  variations  were  by  no  means  extreme.     The  mean  of  the  ages  of  all  the 
individuals  was  27  years.     The  following  is  a  general  statement  of  the  result0 
the  temperature  of  the  body  having  been  ascertained  by  a  thermometer  pi, 
under  the  tongue  : — 

Average  temperature  of  the  body 


Temperature  of  the  air 


Mean  of  all  the  experiments 
Highest  temperature  of  air 
Lowest  temperature  of  air 


60° 

69° 

78° 

79-5< 

80° 

82° 

740 

82° 
60° 


Mean  of  all  the  experiments 
Highest  temperature  of  body 
Lowest  temperature  of  body 


98-28° 

98-15° 

98-85° 

99-21° 

99-67° 

99-9° 

100° 

102° 

96-5° 


From  this  we  see  that  the  variations  noted  by  Dr.  Davy,  which  were  evidently 
in  part  the  consequence  of  variations  in  external  temperature,  but  which  were 
also  partly  attributable  to  individual  peculiarities,  amounted  to  5£  degrees;  the 
lower  extreme  might  be  found  to  undergo  still  further  depression,  if  the  inquiries 
were  carried-on  in  very  cold  climates. — Dr.  Davy's  subsequent  inquiries  have 
been  directed  to  the  determination  of  the  various  influences  which  tend  to  pro- 
duce a  departure  from  the  average;  and  it  will  be  advantageous  to  present  his 
results  in  a  systematized  form,  in  combination  with  those  of  other  observers. 
The  most  important  of  these  variations  seem  to  be  those  dependent  upon  Age, 
Period  of  the  Day,  Exercise  or  Repose,  Ingestion  of  Food  ,or  Drink,  and  External 
Temperature. 

I.  The  temperature  of  Infants,  according  to  the  observations  of  Dr.  Davy,  M. 
Roger2  and  of  Dr.  Gr.  C.  Holland,3  is  somewhat  higher  than   that  of  adults,4 
provided  that  they  are  placed  in  conditions  favourable  to  its  sustenance;  but,  as 
will  be  shown  hereafter,  infants  and  young  children  are  very  inferior  to  adults 
in  their  power  of  resisting  the  depressing  influence  of  external  cold  (§§  442,  443). 
Their  temperature,  when  examined  immediately  after  birth  by  a  thermometer  in 
the  axilla,  is  nearly  100°;  but  it  quickly  falls  to  about  95'5°,  and  gradually 
rises  in  the  course  of  the  next  twenty-four  hours  to  about  97*7°  in  weakly  sub- 
jects, and  to  99-5°  in  strong  infants.     Between  four  months  and  six  years  of 
age,  M.  Roger  found  the  average  temperature  to  be  98'9°;  and  between  six  and 
fourteen  years  of  age,  99-16°. — The  temperature  of  aged  persons,  from   the 
observations  of  Dr.  J.  Davy,  does  not  seem  to  be  below  that  of  persons  in  the 
vigour  of  life,  provided  that  there  be  no  external  depressing  influences ;  but  they 
seem,  like  infants  and  young  children,  to  have  less  power  of  resisting  external 
cold,  the  temperature  of  their  bodies  being  more  easily  and  considerably  reduced 
by  it  than  is  that  of  adults;  and  hence  probably  it  has  happened,  that  popular 
opinion  assigns  to  them  an  habitually  inferior  temperature. 

II.  A  slight  diurnal  variation  in  the  temperature  of  the  body  appears  usually 

1  See  Dr.  Davy's  successive  Memoirs  in  the  "Philosophical  Transactions,"  for  181 4» 
(republished  in  his  "Anatomical  and  Physiological  Researches")  1844,  1845  and  1850. 

a  "  Archiv.  Ge*n.  de  Me*d.,"  1844.  a  "  Inquiry  into  the  Laws  of  Life,"  1829. 

«  Dr.  W.  F.  Edwards  ("On  the  Influence  of  Physical  Agents  on  Life,"  p.  116)  gives  us 
the  result  of  his  observations,  which  were  only  ten  in  number,  that  the  temperature  of 
infants  is  lower  than  that  stated  above ;  but  it  is  obvious  that  these  observations  were 
made  during  the  period  of  depression  which  occurs  in  the  first  few  days,  whilst  the  new 
respiratory  function  is  becoming  established. 


408 


EVOLUTION    OF   HEAT,    LIGHT,    AND    ELECTRICITY. 


to  take  place,  quite  irrespectively  of  external  heat  or  cold ;  but  this  does  not 
seem  to  be  very  constant  either  in  its  period  or  its  degree,  and  is  seldom  very 
considerable.  Thus  Dr.  Davy  found  from  a  long  series  of  observations  carried- 
on  upon  himself  whilst  in  England,  that  the  body  was  warmest  in  the  morning, 
and  coldest  at  night ;  whilst  the  reverse  was  the  case  in  Barbadoes.  The  follow- 
ing table  gives  his  average  results : — 


.... 
Mean  temperature  under  the  tongue. 

Temperature  of  Room, 

**»*     {T9l-74*o 

2-4  P.M. 

98-52° 

12  P.M. 

97-92° 

7-8  A.M. 
50-9° 

2-4  P.M. 
54.7° 

12  P.M. 

62° 

Barbadoes  J  ^A.H. 

12-2  P.M. 

98-9° 

9-11  P.M. 
99° 

6-7  A.M. 

76-7° 

12-2  P.M. 
83-6° 

9-11  P.M. 

79° 

From  the  observations  of  M.  Chossat  on  Birds,  in  which  the  diurnal  variation 
amounts  to  1%°  Fahr.,  it  seems  that  the  maximum  pretty  constantly  occurs  at 
noon,  and  the  minimum  near  midnight;  and  this  corresponds  well  with  what 
has  already  been  pointed-out,  with  regard  to  the  relative  activity  of  respiration 
at  different  periods  of  the  twenty-four  hours  (§  316  ix).  Probably  there  is  a 
less  capacity  for  generating  heat  during  the  night ;  so,  that,  if  the  body  be  in- 
sufficiently protected  by  clothing,  or  be  exposed  to  a  low  degree  of  external 
temperature,  its  own  temperature  will  be  more  readily  lowered :  and  thus  the 
minimum  of  the  whole  day  may  come  to  present  itself  at  this  part  of  it,  in  a 
temperate  climate ;  whilst  in  a  tropical  climate,  the  light  bed-covering  and  free 
circulation  of  air  usual  in  the  sleeping-room,  together  with  the  reducing  influ- 
ence of  repose,  would  tend  to  render  the  early-morning  temperature  the  lowest. 

in.  That  an  increase  in  the  heat  of  the  body  is  produced  by  exercise,  and  that 
repose  tends  to  its  reduction,  is  a  matter  of  familiar  experience ;  but  the  obser- 
vations of  Dr.  Davy  show  that  there  is  scarcely  any  perceptible  difference  in  the 
heat  of  the  deep-seated  parts,  the  augmentation  and  depression  being  confined 
to  the  extremities.  Thus,  on  one  occasion  recorded  by  him,  the  tempera- 
ture of  the  air  of  the  room  before  walking  being  60°,  that  of  the  feet  (shown  by 
a  thermometer  placed  between  the  toes)  being  only  66°,  that  of  the  thermometer 
under  the  tongue  being  98°,  and  that  of  the  urine  being  100°, — the  temperature 
after  a  walk  in  the  open  air  at  40°,  the  exercise  having  diffused  a  feeling  of  gentle 
warmth  through  the  body,  was  96-5°  in  the  feet,  97°  in  the  hands,  98°  under 
the  tongue,  and  101°  in  the  urine.  So,  on  another  occasion,  the  temperature 
having  been  66°  in  the  room,  75°  in  the  feet,  81°  in  the  hands,  98°  under  the 
tongue,  and  100°  in  the  urine, — after  a  walk  in  air  at  50°  the  temperature  was 
99°  in  the  feet,  98°  in  the  hands,  98°  under  the  tongue,  and  101-5°  in  the  urine. 

IV.  The  influence  of  inycstion  of  food  upon  the  temperature  of  the  body  has 
not  yet  been  duly  investigated.  Common  experience  leads  to  the  conclusion,  that 
after  a  meal,  as  after  exercise,  there  is  a  greater  warmth  in  the  extremities;  but 
Dr.  Davy's  observations  show  that,  in  his  own  person,  whilst  in  England,  there 
was  usually  an  appreciable  depression  immediately  after  dinner,  though  in  Barba- 
does the  effect  of  a  moderate  meal  was  to  produce  an  elevation.  In  both  cases, 
however,  Dr.  D.  observed  that  the  ingestion  of  wine  has  a  positively-depressing 
influence  on  the  temperature  of  the  body,  which  increases  with  the  quantity! 
taken;  and  it  may  have  been  the  constant  employment  of  wine  with  his  dinner, 
which  was  the  real  cause  of  the  depression  observed  in  England.1 

1  This  difference  in  effect  noted  by  Dr.  Davy,  between  a  moderate  quantity  of  wine  taken 
with  dinner  in  England  and  in  Barbadoes,  seems  readily  explicable  by  the  fact  that  the 
presence  of  Alcohol  in  the  blood  diminishes  for  a  time  the  energy  of  the  proper  combustive 
process  (%  316  vi).  For  when  the  temperature  of  the  atmosphere  is  considerably  below 
that  of  the  body,  this  retardation  of  the  combustive  process  occasioned  by  the  wine  will 


EVOLUTION    OF    HEAT.  409 

V.  The  influence  of  external  temperature  is  sufficiently  apparent  in  the  obser- 
vations already  cited ;  for  although  external  cold  may  act  in  a  different  degree  oil 
different  individuals,  according  to  their  respective  ages,  powers  of  resistance,  &c., 
yet  there  is  ample  proof  that  on  the  whole  a  continued  exposure  to  it  reduces  the 
temperature  of  the  body  somewhat  below  its  ordinary  standard,  whilst  continued 
exposure  to  heat  occasions  a  slight  elevation  in  the  temperature  of  the  body. 
The  influence  of  cold  is,  of  course,  most  powerfully  exerted  when  the  body  is  at 
rest ;  and  under  such  circumstances  Dr.  Davy  found  the  temperature  of  his  own 
body  to  be  reduced,  on  an  average  of  four  observations,  to  96 '7°,  the  average 
temperature  of  the  surrounding  air  having  been  87°.  On  comparing  the  bodily 
temperature  of  different  individuals  working  in  rooms  of  various  temperatures  in 
the  same  factory,  Dr.  Davy  found  the  tongue-thermometer  to  rise  to  100°  in  one 
man,  and  to  100-5  in  another  who  had  been  working  for  some  hours  in  a  room 
at  92°  ;  whilst  it  was  99°  in  a  young  woman  who  worked  in  a  room  at  78°,  and 
only  97-5°  in  another  who  worked  in  a  temperature  of  60°.  —  The  effects  of 
seasonal  change  are  less  marked  in  Man,  than  they  are  in  the  lower  animals, 
which  are  more  exposed  to  extremes  of  temperature;  but  it  seems  principally 
exerted  in  modifying  the  heat-producing  power.  For  it  has  been  shown  by  Dr. 
W.  F.  Edwards  (Op.  cit),  that  warm-blooded  animals  are  more  speedily  killed 
by  extreme  cold  in  summer  than  in  winter;  and  it  seems  probable,  therefore, 
that  we  are  partly  to  attribute  the  peculiar  chilling  influence  of  a  cold  day  in 
summer,  arid  the  oppressiveness  of  a  warm  day  in  winter,  to  the  seasonal  change 
in  the  body  itself;  although  the  effect  is  doubtless  referable  in  part  to  the  effect 
of  contrast  upon  our  own  feelings. 

428.  The  usual  Temperature  of  the  body  occasionally  undergoes  considerable 
alteration  in  disease  ;  and  this  in  the  way  either  of  increase  or  diminution.  Thus 
in  maladies  which  involve  an  acceleration  of  pulse  and  a  quickening  of  the  res- 
piration, the  temperature  is  generally  higher  than  usual,  even  though  a  large 
portion  of  the  lung  may  be  unfit  for  its  function.  This  is  often  remarkably  seen 
in  the  last  stages  of  phthisis,  when  the  inspirations  are  extremely  rapid,  and  the 
pulse  so  quick  as  scarcely  to  admit  of  being  counted;  the  skin,  in  such  cases, 
often  becomes  almost  painfully  hot.  On  the  other  hand,  in  diseases  of  the  con- 
trary character,  such  as  *  morbus  coeruleus/  asthma,  and  cholera,  the  temperature 
of  the  body  falls ;  a  reduction  to  78°  having  been  noticed  in  the  former  maladies, 
and  to  67°  in  the  latter.  The  range  observed  by  M.  Andral  in  diseases  which 
less  affected  the  calorifying  function,  was  from  95°  to  107'06° ;  and  by  M.  Roger 
(loc.  cit.),  in  diseases  of  children,  from  74-3  to  108-5°.  Prof.  Dunglison1  speaks 
of  having  seen  the  thermometer  at  106°  in  scarlatina  and  typhus;  and  Dr. 
Francis  Home,2  found  it  to  stand  at  104°  in  two  individuals  in  the  cold  stage  of 
an  intermittent,  whilst  it  afterwards  fell  to  101°,  and  subsequently  to  99°,  during 
the  sweating  stage.  Dr.  Edwards  mentions  a  case  of  tetanus,  in  which  the  tem- 
perature of  the  body  rose  to  HOf  °.  The  following  observations  have  been  made 
on  this  subject  by  M.  Donne"  ;3  in  a  case  of  puerperal  fever,  the  pulse  being  168, 
and  the  respirations  48  per  minute,  the  temperature  was  104°;  in  a  case  of 
hypertrophy  of  the  heart,  the  pulse  being  150  and  the  respirations  34,  the  tern 
perature  was  103°;  in  a  case  of  typhoid  fever,  the  pulse  being  136,  and  the 
respirations  50,  the  temperature  was  104°;  and  in  a  case  of  phthisis,  the  pulse 
being  140,  and  the  respirations  62,  the  temperature  was  102°;  on  the  other 

allow  the  heat  of  the  body  to  be  lowered  by  it,  notwithstanding  the  tendency  to  increased 
activity  of  the  circulation  and  respiration  which  the  meal  alone  would  exert.  In  a  warm 
climate,  on  the  other  hand,  the  cooling  influence  of  the  external  air  would  not  be  sufficient 
to  produce  this  reduction  in  the  temperature  of  the  body,  notwithstanding  the  retarding 
influence  of  the  wine  upon  the  combustive  process. 

1  "Human  Physiology,"  7th  edit.,  vol.  ii.  p.  225. 

2  "  Medical  Facts  and  Experiments,"  London,  1759. 

1  "Archiv.  Gen.  de  Me"d.."  Oct.  1835;  and  "  Brit,  and  For.  Med.  Rev.,"  vol.  ii.  p.  248, 


410 

hand,  in  a  case  of  jaundice,  in  which  the  pulse  was  but  52,  the  temperature  was 
only  9640°;  but  the  same  temperature  was  observed  in  a  case  of  diabetes,  in 
which  the  pulse  was  84.  These  limited  observations,  whilst  they  clearly  indicate 
that  a  general  relation  exists  between  the  temperature  of  the  body  and  the 
rapidity  of  the  pulse,  also  show  that  this  relation  is  by  no  means  invariable,  but 
that  it  is  liable  to  be  affected  by  several  causes,  of  which  our  knowledge  is  as  yet 
very  slight.  —  It  is  not  a  little  remarkable  that  the  temperature  of  the  body 
should  sometimes  rise  considerably  after  death;  and  this  not  merely  in  such 
diseases  as  Cholera,  in  which  it  has  undergone  an  extreme  depression  during  the 
latter  part  of  life ;  but  even  in  the  case  of  febrile  disorders,  in  which  the  tem- 
perature during  life  has  been  above  the  usual  standard.  This  has  been  ascer- 
tained by  Dr.  Bennet  Dowler1  of  New  Orleans,  on  the  bodies  of  those  yellow- 
fever  subjects  which  have  already  been  referred-to  as  exhibiting  a  remarkable 
degree  of  molecular  life  after  somatic  death  (§  269).  In  one  case,  for  example, 
the  highest  temperature  during  life  was  in  the  axilla,  104° ;  ten  minutes  after 
death,  it  had  risen  to  109°  in  the  axilla;  fifteen  minutes  afterwards,  it  was  113° 
in  an  incision  in  the  thigh ;  in  twenty  minutes,  the  liver  gave  112° ;  in  one  hour 
and  forty  minutes,  the  heart  gave  109°,  and  the  thigh  in  the  former  incision 
109° ;  and  in  three  hours  after  the  removal  of  all  the  viscera,  a  new  incision  in 
the  thigh  gave  110°.  It  is  curious  that  the  maximum  heat  observed  after  death 
should  have  been  in  the  thigh,  and  the  minimum  in  the  brain ;  as  is  shown  in 
the  following  table  of  the  highest  amount  of  temperature  noted  in  eight  different 
regions  in  five  subjects  : — 


Thigh. 

Epigastrium. 

Axilla. 

Chest. 

Heart. 

Brain. 

Rectum. 

Liver. 

113° 

111° 

109° 

107° 

109° 

102° 

111° 

112° 

109° 

110° 

109° 

106-5° 

106° 

101° 

109° 

109° 

109° 

109° 

108° 

106° 

105° 

101° 

107° 

108° 

109° 

109° 

108° 

106° 

104° 

100° 

107° 

107° 

108° 

109° 

107° 

105° 

104° 

99° 

106° 

106° 

Mean    109-6°       109-6°       108-2°       106-1°       105-6°       100-6°        108°          108-4° 

429.  Although  there  appears  to  be,  for  all  kinds  of  animals,  a  distinct  limit 
to  the  variations  of  bodily  temperature,  under  which  their  vital  operations  can 
be  carried  on,  this  limitation  does  not  prevent  certain  species  from  existing  in 
the  midst  of  great  diversities  of  external  conditions;  since  they  have  within 
themselves  the  power  of  compensating  for  these,  in  a  very  extraordinary  degree. 
This  power  seems  to  exist  in  Man  to  a  higher  amount  than  in  most  other  animals; 
since  he  can  not  only  support,  but  enjoy  life,  under  extremes  of  which  either 
would  be  fatal  to  many.  In  many  parts  of  the  tropical  zone,  the  thermometer 
rises  every  day,  through  a  large  portion  of  the  year,  to  110°;  and  in  British 
India,  it  is  said  to  be  seen  occasionally  at  130°.  On  the  other  hand,  the  degree 
of  cold  frequently  sustained  by  Arctic  voyagers,  and  quite  endurable  under 
proper  precautions,  appears  much  more  astonishing;  by  Captain  Parry,  the  ther- 
mometer has  been  shown  as  low  as  —  55°,  or  87°  below  the  freezing  point;  by 
Captain  Franklin  — 58°,  or  90°  below  the  freezing  point ;  and  by  Captain  Back 
at  — 70°,  or  102°  below  the  freezing  point.  In  both  cases,  the  effect  of  the  at- 
mospheric temperature  on  the  body  is  greatly  influenced  by  the  condition  of  the 
air  as  to  motion  or  rest :  thus,  every  one  has  heard  of  the  almost  unbearable 
oppressiveness  of  the  *  sirocco ;  or  hot  wind  of  Sicily  and  Italy,  the  actual  tem- 
perature of  which  is  not  higher  than  has  often  been  experienced  without  any 
great  discomfort,  when  the  air  is  calm ;  and,  on  the  other  side,  it  may  be  men- 
tioned that,  in  the  experience  of  many  Arctic  voyagers,  a  temperature  of  — 50° 
may  be  sustained,  when  the  air  is  perfectly  still,  with  less  inconvenience  than  is 

1  "Western  Journal  of  Medicine  and  Surgery,"  June  and  Oct.,  1844;  cited  in  "Phila- 
delphia Medical  Examiner,"  June,  1845,  and  in  Prof.  Dunglison's  "Human  Physiology," 
7th  edit,  vol.  ii.  p.  718. 


EVOLUTION     OF    HEAT.  411 

cmised  by  air  in  motion  at  a  temperature  fifty  degrees  higher.1     This  is  quite 
conformable  to  what  might  be  anticipated  on  physical  principles. 

430.  Again,  the  degree  of  moisture  contained  in  a  heated  atmosphere,  makes 
a  great  difference  in  the  degree  of  elevation  of  temperature,  which  may  be  sus- 
tained without  inconvenience.     Many  instances  are  on  record,  of  a  heat  of  from. 
250°  to  280°  being  endured  in  dry  air  for  a  considerable  length  of  time,  even  by 
persons  unaccustomed  to  a  particularly  high  temperature;  and  persons  whose 
occupations  are  such  as  to  require  it,  can  sustain  a  much  higher  degree  of  heat, 
though  not  perhaps  for  any  long  period.     The  workmen  of  the  late  Sir  F.  Chan- 
trey  were  accustomed  to  enter  a  furnace  in  which  his  moulds  were  dried,  whilst 
the  floor  was  red-hot,  and  a  thermometer  in  the  air  stood  at  350°;  and  Chabert 
the  "  Fire-king/'  was  in  the  habit  of  entering  an  oven  whose  temperature  was 
from  400°  to  6000.2     It  is  possible  that  these  feats  might  be  easily  matched  by 
many  workmen  who  are  habitually  exposed  to  high  temperatures ;  such  as  those 
employed  in  Iron-foundries,  Glass-houses,  and  Gas-works.     In  all  these  instances, 
the  dryness  of  the  air  facilitates  the  rapid  vaporization  of  the  fluid,  whose  secre- 
tion by  the  Cutaneous  glandules  is  promoted  by  heat  applied  to  the  surface;  and 
the  large  amount  of  caloric  which  is  consumed  in  this  change,  is  for  the  most 
part  withdrawn  from  the  body,  the  temperature  of  which  is  thus  kept-down. 

431.  Exposure  to  a  very  elevated  temperature,  however,  if  continued  for  a 
sufficient  length  of  time,  does  produce  a  certain  elevation  of  that  of  the  body;  as 
might  be  expected  from  the  statements  already  made,  in  regard  to  the  variation 
in  the  heat  of  the  body  with  changes  in  atmospheric  temperature  (§  427).     In 
the  experiments  of  MM.  Berger  and  Delaroche,3  it  was  found  that,  after  the 
body  had  been  exposed  to  air  of  120°  during  17  minutes,  a  thermometer  placed 
in  the  mouth  rose  nearly  7°  above  the  ordinary  temperature ;  it  may  be  remarked, 
however,  that  as  the  body  was  immersed  in  a  close  box,  from  which  the  head  pro- 
jected (in  order  to  avoid  the  direct  influence  of  the  heated  air  on  the  temperature 
of  the  mouth),  the  air  had  probably  become  charged  with  the  vapour  exhaled 
from  the  surface,  and  had  therefore  somewhat  of  the  effects  of  a  moist  atmo- 
sphere.    At  any  rate,  the  temperature  of  the  body  does  not  appear  to  rise,  under 
any  circumstances,  to  a  degree  very  much  greater  than  this.     In  one  of  the  ex- 
periments of  Drs.  Fordyce  and  Blagden,4  the  temperature  of  a  Dog,  that  had 
been  shut-up  for  half-an-hour  in  a  chamber  of  which  the  temperature  was  between 
220°  and  236°,  was  found  to  have  risen  from  101°  to  about  108°.     MM.  Dela- 
roche and  Berger  tried  several  experiments  on  different  species  of  animals,  in 
order  to  ascertain  the  highest  temperature  to  which  the  body  could  be  raised 

1  The  Author  has  been  informed  by  Sir  John  Richardson,  that  in  his  last  Arctic  Expedi- 
tion, whilst  at  winter-quarters,  he  was  accustomed  to  go  from  his  sitting-room  to  the  mag- 
netic observatory  at  a  short  distance  (about  an  ordinary  street's  breadth),  without  feeling 
it  necessary  even  to  put  on  a  great-coat ;  although  the  temperature  of  the  former  was 
about  50°,  and  that  of  the  air  through  which  he  had  to  pass  to  the  latter  was — 50°,  the 
difference  being  100°.     This  immunity  from  chilling  influence  was  chiefly  attributable  to 
the  dryness  and  stillness  of  the  atmosphere  ;  but  it  is  worthy  of  note  that  Sir  J.  R.  and 
the  whole  of  his  party  on  this  expedition,  abstained  entirely  from  alcoholic  liquors ;  and 
the  Author  has  received  his  personal  assurance,  that  his  experience  on  this  occasion  fully 
bore-out  his  previous  conviction,  that  continued  severe  cold  is  much  better  borne  without 
recourse  to  these  liquors,  than  under  the  employment  of  them. 

2  The  wonderful  feats  performed  by  many  individuals  from  time  to  time, — of  dipping 
the  hand  into  melted  lead,  laying  hold  of  a  red-hot  iron,  &c., — have  been  recently  shown 
by  M.  de  Boutigny  to  be  explicable  upon  very  simple  principles.     For  in  all  such  cases,  a 
tliin  film  of  aqueous  fluid  in  the  'spherical  state'  intervenes  between  the  skin  and  the  heated 
surface ;  and  a  hand  which  is  naturally  damp,  or  which  has  been  slightly  moistened,  may 
be  safely  passed  into  the  stream  of  molten  iron  as  it  flows  from  the  furnace ;  as  was  demon- 
strated by  M.  de  Boutigny  at  the  meeting  of  the  British  Association  at  Ipswich  in  1851. 

3  "Experiences  sur  lee  Effets  qu'une  forte  Chaleur  produit   sur  PEconomie;"  Paris, 
1805  ;  and  "Journal  de  Physique,"  tomes  Ixiii.,  Ixxi.,  et  Ixxvii. 

4  "  Philosophical  Transactions,"  1775. 


412  EVOLUTION   OF   HEAT,    LIGHT,    AND    ELECTRICITY. 

without  the  destruction  of  life,  by  inclosing  them  in  air  heated  from  122°  to 
201°,  until  they  died  :  the  result  was  very  uniform,  the  temperature  of  the  body 
at  the  end  of  the  experiment  only  varying  in  the  different  species  between  11° 
and  13°  above  their  natural  standard  :  whence  it  may  be  inferred,  that  an  eleva- 
tion to  this  degree  must  be  fatal.  This  elevation  would  be  attained  comparatively 
soon  in  a  moist  atmosphere ;  partly  because  of  the  greater  conducting  power  of 
the  medium,  but  principally  on  account  of  the  check  which  is  put  upon  the  vapo- 
rization of  the  fluid  secreted  by  the  skin.  Even  here,  however,  custom  and 
acquired  constitution  have  a  very  striking  influence ;  for  whilst  the  inhabitants 
of  this  country  are  unable  to  sustain,  during  more  than  10  or  12  minutes,  im- 
mersion in  a  vapour-bath  of  the  temperature  of  110°  or  120°,  the  Finnish 
peasantry  remain  for  half  an  hour  or  more  in  a  vapour-bath  whose  temperature 
finally  rises  even  to  158°  or  167°. — Accurate  experiments  are  yet  wanting,  to 
determine  the  influence  of  humidity  on  the  effects  of  cold  air.  From  experi- 
ments on  young  Birds  incapable  of  maintaining  their  own  temperature,  of  which 
some  were  placed  in  cold  dry  air,  and  others  in  cold  air  charged  with  moisture, 
it  was  found  by  Dr.  Edwards  that  the  loss  of  heat  was  in  both  instances  the 
same ;  the  effect  of  the  evaporation  from  the  surface  in  the  former  case,  being 
counterbalanced  in  the  latter  by  the  depressing  influence  of  the  cold  moisture. 
This  influence,  the  existence  of  which  is  a  matter  of  ordinary  experience,  is  pro- 
bably exerted  directly  upon  the  Nervous  system. 

432.  Having  thus  considered  the  general  facts  which  indicate  the  faculty  pos- 
sessed by  the  living  system,  in  Man  and  the  higher  Annals,  of  keeping-up  its 
temperature  to  an  elevated  standard,  and  of  preventing  it  from  being  raised  much 
beyond  it  by  any  degree  of  external  heat,  we  have  next  to  inquire  to  what  this 
faculty  is  due.1 — It  may  be  stated  as  a  general  fact,  that  every  change  in  the 
condition  of  the  organic  components  of  the  body,  in  which  their  elements  enter 
into  new  combinations  with  Oxygen,  must  be  a  source  of  the  development  of 
Heat.  And  as  we  have  seen  that  a  considerable  part  of  the  carbonic  acid  and 
water  which  are  exhaled  in  Respiration,  is  formed  within  the  body  by  the  meta- 
morphosis of  its  own  tissues,  and  that  this  metamorphosis  is  promoted  by  the 
active  exercise  of  the  nervo-muscular  apparatus,  it  follows  that  in  animals  whose 
habits  of  life  are  peculiarly  active,  whilst  the  temperature  of  the  surrounding  mer 
diurn  is  sufficiently  high  to  prevent  its  exerting  any  considerable  cooling  influence 
over  them,  the  combustive  process  thus  maintained  may  be  adequate  for  the 
maintenance  of  the  temperature  of  the  body  at  its  normal  standard.  This  seems 
to  be  the  case  with  the  great  Carnivorous  quadrupeds  of  warm  climates,  and  with 
certain  races  of  Men  who  lead  a  life  of  incessant  activity  like  theirs.  But  when- 
ever the  cooling  influence  of  the  atmosphere  is  greater,  or  the  retrograde  meta- 
morphosis of  tissue  takes  place  with  less  activity,  some  further  supply  of  heat- 
producing  material  is  required ;  and  this  is  derived  either  directly  from  the  food, 
or  from  a  store  previously  laid-up  in  the  body.  Although  the  albuminous  and 
gelatinous  components  of  the  food  may  be  made,  by  decomposition  within  the 
body,  to  yield  saccharine  and  oleaginous  compounds  which  serve  as  an  immediate 
pabulum  to  the  combustive  process  (§  402),  yet  this  metamorphosis  involves  a 
great  waste  of  valuable  nutritive  material ;  acrd  the  needed  supply  is  much  more 
advantageously  derived  at  once  from  those  farinaceous  or  oleaginous  substances, 
which  are  furnished  in  abundance  by  the  Vegetable  kingdom,  the  latter  also  by 
the  Animal  (§  54).  No  reasonable  doubt  can  any  longer  ba  entertained,  that  the 
production  of  Heat  by  the  combustive  process  is  the  purpose  to  which  these  sub- 

1  It  was  affirmed  by  Dr.  Granville  ("  Phil.  Trans.,"  1825)  that  the  temperature  of  the 
uterus  during  parturition  sometimes  rises  as  high  as  120°.  In  some  observations  made  at 
the  Philadelphia  Hospital,  however,  at  the  desire  of  Prof.  Dunglison,  the  temperature  of 
the  uterus  was  not  found  to  be  mucii  above  that  of  the  vagina ;  the  former  being,  in  three 
cases,  100°.  102°,  and  106°,  whilst  the  latter  was  100°,  100°,  and  105°.  (Prof.  Dungli- 
eou's  '*  Human  Physiology,"  7th  edit,  vol.  ii.  p.  226.) 


EVOLUTION    OF    HEAT.  413 

stances  are  destined  to  be  subservient  in  the  bodies  of  Herbivorous  animals  and 
of  Man ;  and  the  result  of  experience  in  regard  to  their  relative  heat-producing 
powers,  are  in  precise  accordance  with  the  indications  afforded  by  their  chemical 
composition. 

433.  Our  knowledge  of  the  dependence  of  all  the  vital  processes  in  warm- 
blooded animals  upon  the  Heat  of  their  bodies,  and  of  the  dependence  of  their 
calorifying  power  upon  the  due  supply  of  material  for  the  combustive  process, 
has  received  some  remarkable  additions  from  the  experiments  of  M.  Chossatupon 
Starvation.1     He  found  that  Birds,  when  totally  deprived  of  food  and  drink,  suf- 
fered a  progressive,  though  slight,  daily  diminution  of  temperature.     This  dimi- 
nution was  not  so  much  shown  by  a  fall  of  their  maximum  heat,  as  by  an  increase 
in  the  diurnal  variation,  which  he  ascertained  to  occur  even  in  the  normal  state 
(§  427  n).     The  average  variation  in  the  inanitiated  state,  was  about  6°  (instead 
of  1^°),  gradually  increasing  as  the  animal  became  weaker;  moreover,  the  gra- 
dual rise  of  temperature,  which  should  have  taken  place  between  midnight  and 
noon,  was  retarded;  whilst  the  fall  subsequently  to  noon  commenced  much  ear- 
lier than  in  the  healthy  state ;  so  that  the  average  of  the  whole  day  was  lowered 
by  about  4£°,  between  ihejirst  and  the  penultimate  days  of  this  condition.     On 
the  last  day,  the  production  of  heat  diminished  very  rapidly,  and  the  thermometer 
fell  from  hour  to  hour,  until  death  supervened ;  the  whole  loss  on  that  day  being 
about  25°  Fahr.,  making  the  total  depression   about  29 £°.     This   depression 
appears  from  the  considerations  to  be  presently  stated  to  be  the  immediate  cause 
of  Death. — On  examining  the  amount  of  loss  sustained  by  the  different  organs 
of  the  body,  it  was  found  that  93  per  cent,  of  the  Fat  had  disappeared ;  being 
all,  in  fact,  which  could  be  removed ;  whilst  the  nervous  centres  scarcely  ex- 
hibited any  diminution  in  weight  (§  70).    From  the  constant  coincidence  between 
the  entire  consumption  of  the  fat,  and  the  depression  of  temperature, — joined  to 
the  fact  that  the  duration  of  life  under  the  inanitiating  process  evidently  varied 
(other  things  being  equal)  with  the  amount  of  fat  previously  accumulated  in  the 
body, — the  inference  seems  irresistible,  that  the  calorifying  process  depended 
chiefly,  if  not  entirely,  on  the  materials  supplied  by  this  substance.     Whenever, 
therefore,  the  store  of  combustible  matter  in  the  system  was  exhausted,  the 
inanitiated  animals  died,  by  the  cooling  of  their  bodies  consequent  upon  the  loss 
of  calorifying  power. 

434.  That  this  is  the  real  explanation  of  the  fact,  was  shown  by  the  results  of 
a  series  of  very  remarkable  experiments  performed  by  M.  Chossat,  with  the  pur- 
pose of  testing  the  correctness  of  this  view.     When  inanitiated  animals,  whose 
death  seemed  impending,  (death  having  actually  taken  place  in  several  instances, 
whilst  the  preliminary  processes  of  weighing,  the  application  of  the  thermometer, 
&c.,  were  being  performed),  were  subjected  to  artificial  heat,  they  were  almost 
uniformly  restored,  from  a  state  of  insensibility  and  want  of  muscular  power,  to 
a  condition  of  comparative  activity ;  their  temperature  rose,  their  muscular  power 
returned,  they  flew  about  the  room,  and  took  food  when  it  was  presented  to  them; 
and  if  the  artificial  assistance  was  sufficiently  prolonged,  and  they  were  not  again 
subjected  to  the  starving  process,  most  of  them  recovered.     If  they  were  left  to 
themselves  too  early,  however,  the  digestive  process  was  not  performed,  and  they 
ultimately  died.     Up  to  the  time  when  they  began  to  take  food,  their  weight 
continued  to  diminish ;  the  secretions  being  renewed,  under  the  influence  of  arti- 
ficial heat,  sometimes  to  a  considerable  amount.     It  was  not  until  digestion  had 
actually  taken  place  (which,  owing  to  the  weakened  functional  power,  was  com-> 
inonly  many  hours  subsequently  to  the  ingestion  of  the  food),  that  the  animal 
regained  any  power  of  generating  heat ;  so  that,  if  the  external  source  of  heat  was 
withdrawn,  the  body  at  once  cooled :  and  it  was  not  until  the  quantity  of  food 
actually  digested  was  sufficient  to  support  the  wants  of  the  body,  that  its  inde. 

1  "Recherches  Expe"rimentales  sur  1'Iuanition,"  Paris,  1843;  an  analysis  of  this  work 
will  be  found  in  the  "  Brit,  and  For.  Med.  Rev.,"  April,  1844 


414  EVOLUTION    OF   HEAT,    LIGHT,    AND   ELECTRICITY. 

pendent  power  of  calorification  returned.  It  is  to  be  remembered  that,  in  such 
cases,  the  resources  of  the  body  are  on  the  point  of  being  completely  exhausted, 
when  the  attempt  at  re-animation  is  made ;  consequently  it  has  nothing  what- 
ever to  fall-back  upon;  and  the  leaving  it  to  itself  at  any  time  until  fresh 
resources  have  been  provided  for  it  is  consequently  as  certain  a  cause  of  death, 
as  it  would  have  been  in  the  first  instance. 

435.  It  can  scarcely  be  questioned,  from  the  similarity  of  the  phenomena, 
that  Inanitiation,  with  its  consequent  depression  of  temperature,  is  the  imme- 
diate cause  of  death  in  various  diseases  of  Exhaustion  :  and  it  seems  probable 
that  there  are  many  cases,  in  which  the  depressing  cause   is  of  a  temporary 
nature,  and  in  which  a  judicious  and  timely  application  of  artificial  heat  might 
prolong  life  until  it  has  passed-off,  just  as  artificial  respiration  is  serviceable  in 
cases  of  narcotic  poisoning  (§  224).     It  is  especially,  perhaps,  in  those  forms  of 
Fever,  in  which  no  decided  lesion  can  be  discovered  after  death,  that  this  view 
has  the  strong,  st  claim  to  reception;  and  the  beneficial  result  of  the  administra- 
tion of  Alcohol  in  such  conditions,  and  the  large  amount  in  which  it  may  be 
given  with  impunity,  may  probably  be  accounted-for  on  this  principle.     That  it 
acts  as  a  specific  stimulus  to  the  Nervous  system,  cannot  be  doubted  from  its 
effects  on  the  healthy  body;  but  that  it  serves  as  a  fuel  to  keep-up  the  calorifying 
process,  appears  equally  certain.     Its  great  efficacy  in  such  cases  seems  to  depend 
upon  the  readiness  with  which  it  will  be  taken  into  the  circulation,  by  a  simple 
act   of  endosmotic  imbibition,  when  the  special  Absorbent  process,  dependent 
upon  the  peculiar  powers  of  the  cells  of  the  villi  (§  121),  is  in  abeyance.    There 
is  no  other  combustible  fluid,  whose  miscibility  and  density,  relatively  to  that  of 
the  Blood,  will  permit  of  its  rapid  absorption  by  the  simple  physical  process 
adverted-to.1 

436.  That  the  oxidation  of  certain  components  of  the  food  or  of  the  tissues  is 
the  fundamental  source  of  Animal  Heat,  is  further  indicated  by  the  close  con- 
formity which  we  everywhere  find,  between  the  activity  of  the  Respiratory  pro- 
cess and  the  amount  of  Heat  which  is  generated ;  and  this  not  merely  when  we 
compare  different  tribes  of  animals  with  each  other,  but  also  when  we  compare 
the  amount  of  oxygen  absorbed  and  of  carbonic  acid  exhaled  by  the  same  indi- 
viduals under  different  degrees  of  external  temperature  (§  316  i).     For  we  find 
that  the  system  possesses  within  itself  a  regulating  power,  by  which  the  combus- 
tive  process  is  augmented  in  activity  when  the  cooling  influence  of  the  surround- 
ing medium  is  considerable,  so  that  this  influence  is  resisted;  whilst  the  internal 
fire  (so  to  speak)  is  slackened,  whenever  the  temperature  of  the  outer  air  rises 
so  much,  as  to  render  the  same  generation  of  heat  no  longer  requisite.     The 
appetite  for  food,  and  especially  for  those  particular  forms  of  it  which  best  afford 
the  combustive  pabulum,  varies  in  the  same  degree ;  and  thus,  when  supplied 
with  appropriate  nutriment,  Man  is  able  to  brave  the  severest  cold,  without  suf- 
fering any  considerable  depression  in  his  bodily  temperature.  —  It  would  seem 
that  the  Cutaneous  Respiration  (§  317),  small  as  its  amount  is,  promotes  those 
molecular  changes  on  which  the  maintenance  of  Animal  Heat  depends;  for  it 
was  found  by  MM.  Becquerel  and  Breschet,2  that  when  the  hair  of  Rabbits  was 
shaved-off,  and  a  composition  of  glue,  suet,  and  resin  (forming  a  coating  imper- 
meable to  the  air)  was  applied  to  the  whole  surface,  the  temperature  rapidly  fell, 
notwithstanding  the   obstacle  thus   offered  to  the   evaporation   of  the   sweat, 
whereby,  it  might  be  supposed,  the  temperature  of  the  body  would  be  consider- 
ably elevated.     In  the  first  rabbit,  which  had  a  temperature  of  100°  before  being 
shaved  and  plastered,  it  had  fallen  to  89  £°  by  the  time  the  material  spread  over 

1  The  Author  has  stated  the  very  striking  results  of  observations  which  he  has  had  the 
opportunity  of  making  upon  this  point,  in  his  Essay  "  The  Physiology  of  Temperance  and 
Total  Abstinence,"  \  213. 

4  "Comptes  Rendus,"  Oct.  1841.  These  experiments  have  been  repeated  and  confirmed 
ny  Magendie  ("Gazette  MeMicale,"  Dec.  6,  1843). 


EVOLUTION      OF    HEAT.  415 

him  was  dry.  An  hour  afterwards,  the  thermometer  placed  in  the  same  parts 
(the  muscles  of  the  thigh  and  chest)  had  descended  to  76°  In  another  rabbit, 
prepared  with  more  care,  by  the  time  that  the  plaster  was  dry,  the  temperature  of 
the  body  was  not  more  than  5|°  above  that  of  the  surrounding  medium,  which 
was  at  that  time  69£°;  and  in  an  hour  after  this,  the  animal  died.  —  These  ex- 
periments place  in  a  very  striking  point  of  view  the  importance  of  the  cutaneous 
surface  as  a  respiratory  organ,  even  in  the  higher  animals ;  and  they  enable  us 
to  understand  how,  when  the  aerating  power  of  the  Lungs  is  nearly  destroyed  by 
disease,  the  heat  of  the  body  is  kept-up  to  its  natural  standard  by  the  action  of 
the  Skin.  A  valuable  therapeutic  indication,  also,  is  derivable  from  the  know- 
ledge which  we  thus  gain,  of  the  importance  of  the  cutaneous  respiration ;  foi 
it  leads  us  to  perceive  the  desirableness  of  keeping  the  skin  moist,  in  those 
febrile  diseases  in  which  there  is  great  heat  and  dryness  of  the  surface,  since 
aeration  cannot  properly  take  place  through  a  dry  membrane.  Of  the  relief 
afforded  by  cold  or  tepid  sponging  in  such  cases,  experience  has  given  ample 
evidence. 

437.  It  has  been  held  that  the  Chemical  theory  of  Calorification  is  insufficient 
to  account  for  the  total  amount  of  Heat  generated  by  a  warm-blooded  animal  in 
a  given  time ;  this  assertion  being  founded  upon  the  experimental  results  obtained 
by  M.  Dulong.     MM.  Fabre  and  Silbermann1  have  shown,  however,  that  the 
original  estimates  require  correction  for  the  true  calorific  equivalents  of  carbon 
and  hydrogen ;  and  that  this  correction  having  been  made,  the  heat  produced  by 
the  combustion  of  the  Carbon  which  is  contained  in  the  carbonic  acid  expired, 
and  by  the  combustion  of  such  a  proportion  of  the  Hydrogen  contained  in  the 
exhaled  water  as  maybe  fairly  considered  to  have  undergone  oxygenation  within 
the  system  (§  321),  proves  to  be  adequate  to  compensate  for  that  which  would 
be  dissipated  by  the  evaporation  of  all  the  water  transpired  from  the  skin  and 
lungs,  and  also  to  maintain  the  temperature  of  the  body  itself  in  an  atmosphere 
of  ordinary  coolness.     And  to  the  combustion-heat  of  carbon  and  hydrogen,  we 
should  also  add  that  of  those  relatively-minute  quantities  of  Phosphorus  and  Sul- 
phur, which  also  undergo  oxidation  within  the  system  (§  414),  whereby  a  small 
additional  amount  of  heat  must  be  generated. — Through  whatever  diversity  of 
combinations  or  successive  stages  of  oxidation  these  elements  respectively  pass, 
in  their  progress  to  complete  or  final  oxidation,  it  may  be  regarded  as  an  indis- 
putable fact,  that  they  give-out  precisely  the  same  amount  of  heat  in  the  whole, 
as  if  they  had  undergone  the  most  rapid  combustion  in  pure  oxygen  ;  and  thus 
we  may  look  to  almost  every  molecular  change  in  the  body,  although  pre-emi- 
nently to  those  which  are  concerned  in  the  disintegration  of  its  textures  and  in 
the  elimination  of  their  products  by  Respiration,  as  participating  in  the  function 
of  Calorification. 

438.  It  cannot  be  denied,  however,  that  there  are  certain  phenomena  which 
seem  at  first  sight  to  be  completely  opposed  to  this  doctrine,  and  which  can 
scarcely  be  explained  in  accordance  with  it,  save  by  a  considerable  modification  in 
our  usual  ideas.     The  class  of  facts  to  which  reference  is  here  made  are  those 
which  indicate  that  the  Nervous  System  has  a  very  important  concern  in  the 
process,  and  that  it  is,  in  fact,  one  of  the  immediate  instruments  in  the  develop- 
ment of  heat.     Thus  it  was  experimentally  shown  by  Sir  B.  Brodie,2  that  when 
the  Brain  is  cut-off  from  the  spinal  cord,  or  its  functions  are  suspended  by  the 
agency  of  a  narcotic,  and  artificial  respiration  is  practised,  so  that  the  circulation 
is  maintained,  the  body  not  only  loses  heat  rapidly,  but  may  even  cool  more 
rapidly  than  the  body  of  an  animal  similarly  treated,  but  in  which  artificial 
respiration  is  not  performed.     Now  it  is  certainly  true,  as  was  subsequently 
pointed-out  by  Drs.  Wilson  Philip  and  Hastings,3  and  by  Dr.  C.  Williams,4  that 

1  See  their  Memoir  <Des  Chaleurs  de  Combustion,'  in  "Compt.  Rend.,"  torn,  xx.,  xxii. 
a  "Philosophical  Transactions,"  1811,  1812;  and  "Physiological  Researches." 

3  See  Dr.  Wilson  Philip's  "Experimental  Enquiry  into  the  Laws  of  the  Vital  Fmictiuhu," 
3rd  edit.,  p.  180. 

4  "Edinb.  Med.-Chir.  Trans.,"  vol.  ii.,  p.  192. 


416  EVOLUTION   OF   HEAT     LIGHT,    AND    ELECTRICITY. 

the  effect  of  the  artificial  performance  of  respiration  depends  in  some  degree 
upon  the  mode  in  which  it  is  accomplished ;  for  that  if,  as  in  most  of  Sir  B. 
Brodie's  experiments,  the  insufflation  be  repeated  30  times  or  more  in  a  minute, 
the  cooling  effect  of  the  air  thus  introduced  is  greater  than  the  warming  effect 
of  the  imperfect  respiratory  change  ro  which  it  becomes  subservient;  whilst  if 
the  insufflation  be  repeated  only  12  times  in  a  minute,  the  cooling  of  the  body, 
as  compared  with  that  of  a  body  in  which  the  circulation  is  not  thus  maintained, 
is  retarded,  instead  of  being  accelerated.  But  still  it  is  evident  from  Sir  B. 
Brodie's  experiments,  that  the  withdrawal  of  the  influence  of  the  Encephalon 
has  a  positively-depressing  effect  upon  the  Calorific  function ;  for  the  rapid  fall 
of  temperature  took  place  even  in  cases,  in  which  the  amount  of  carbonic  acid 
exhaled  during  the  performance  of  artificial  respiration  was  fully  equal  to  the 
normal  quantity;  and  the  subsequent  experiments  of  MM.  Le  Gallois1  and 
Chossat2  are  decidedly  confirmatory  of  this  conclusion,  whilst  they  extend  it  to 
other  lesions  of  the  Nervous  centres,  the  influence  of  which  upon  the  calorific 
function  appears  to  be  proportional  to  their  severity. — Various  pathological  phe- 
nomena, moreover,  indicate  that  the  withdrawal  of  nervous  influence  from  any 
part  of  the  body  usually  tends  to  produce  a  depression  of  its  temperature,  and 
this  especially  in  the  extremities;  thus  Mr.  H.  Earle3  found  the  temperature  of 
paralysed  limbs  slightly  lower  than  that  of  sound  limbs;  so  Prof.  Dunglison  has 
noticed  that  in  one  case  of  hemiplegia  of  five  months'  standing,  the  temperature 
of  the  axilla  was  96J°  on  the  sound  side,  and  96°  on  the  paralysed;  whilst  that 
of  the  hand  was  87°  on  the  sound  side  and  only  79?°  on  the  paralysed;  and  in 
another  case  of  only  a  fortnight's  duration,  the  temperature  of  the  axilla  was  100° 
on  the  sound  side,  and  only  98 J°  on  the  paralysed,  whilst  that  of  the  hand  was 
94°  on  the  sound  side,  and  90°  on  the  paralysed.4 

489.  It  is  a  remarkable  fact,  however,  that  the  disturbance  of  temperature 
produced  by  severe  injuries  of  the 'Nervous  system,  occasionally  shows  itself  in 
the  opposite  direction.  Thus  it  has  been  noticed  by  many  experimenters,  that 
one  of  the  first  effects  of  division  of  the  spinal  cord  in  the  back,  in  warm-blooded 
animals,  is  to  raise  the  temperature  of  the  posterior  part  of  the  body,  this  eleva- 
tion continuing  for  some  hours.  A  case  is  recorded  by  Sir  B.  Brodie,  in  which, 
the  spinal  cord  having  been  so  seriously  injured  in  the  lower  part  of  the  cervical 
region  that  the  whole  of  the  nerves  passing-off  below  were  completely  paralysed, 
the  heat  of  the  body,  as  shown  by  a  thermometer  placed  on  the  inside  of  the 
groin,  was  not  less  than  111°;  and  this  notwithstanding  that  the  respiratory 
function  was  very  imperfectly  performed,  the  number  of  inspirations  being  con- 
siderably reduced,  and  the  countenance  being  livid.5  And  Prof.  Dunglison  states 
that,  notwithstanding  the  usual  depression  of  the  thermometer  on  the  hemiplegic 
side,  it  is  not  unfrequently  found  to  be  more  elevated  than  on  the  sound,  side.6 
According  to  the  recent  experiments  of  M.  Cl.  Bernard7  it  appears  that  an  ele- 
vation of  temperature  constantly  takes  place  on  one  side  of  the  face,  when  the 
trunk  which  unites  the  Sympathetic  ganglia  of  the  neck  on  that  side  is  cut 
through ;  this  increase  being  not  only  perceptible  to  the  touch,  but  showing  itself 
by  a  thermometer  introduced  into  the  nostrils  or  ears,  even  to  the  extent  of  from 
7°  to  11°  Fahr.  When  the  superior  cervical  ganglion  is  removed,  the  same 
effect  is  produced,  and  with  greater  intensity.  This  difference  is  maintained  for 
many  months,  and  is  not  apparently  connected  with  the  occurrence  of  inflam- 
mation, congestion,  O3dema,  or  any  other  pathological  change  in  the  tissues, 

'Annales  deChimie,"  1817;  and  "  (Euvres  de  M.  Le  Gallois,"  torn.  ii. 

'Memoirs  sur  1'Influence  de  Systeme  Nerveux  sur  la  Chaleur  Animale." 

'  Medico-Chirurgical  Transactions,"  vol.  vii. 

'  Human  Physiology,"  7th  edit.  vol.  ii.  p.  238. 

'Medical  Gazette,"  June,  1836;   and  "Physiological  Researches,"  p.  121. 

'Ainer.  Med.  Intelligencer,"  Oct.  18,  1838. 

'Gazette  Me'dicale,"  Fevr.  21,  1852. 


EVOLUTION    OF    HEAT.  417 

though  the  sensibility  of  the  parts  thus  affected  is  no  less  augmented  than  their 
temperature  j  moreover,  it  is  not  prevented  from  manifesting  itself  by  the  divi- 
sion of  any  of  the  cerebro-spinal  nerves  of  the  face.  The  fact,  however,  appears 
to  be  sufficiently  explained  by  the  relaxation  of  the  walls  of  the  smaller  arteries 
(producing  a  state  resembling  a  permanent  'blush'),  and  the  consequent  increase 
in  the  afflux  of  blood  to  the  part,  which  has  been  shown  by  Dr.  Aug.  Waller  to 
result  from  this  operation.  (See  §  257.) 

[Dr.  Brown-Sequard  has  observed  the  same  remarkable  phenomena  as  those 
detailed  by  M.  Cl.  Bernard,  but  he  regards  them  as  mere  results  of  the  paralysis, 
and  of  the  consequent  dilatation  of  the  blood-vessels.  In  consequence  of  this 
dilatation,  the  blood  reaches  the  part  supplied  by  the  nerve  in  larger  quantities; 
the  nutrition  is  therefore  more  active.  The  increased  sensibility  is  a  result  of 
the  augmented  vital  properties  of  the  nerves  when  their  nutrition  is  increased. 
Dr.  Brown-Sequard  has  likewise  noticed  the  increase  of  temperature  of  the  ear 
over  that  of  the  rectum,  to  the  amount  of  one  or  two  degrees  Fahr.  j  but  it  must 
be  remembered  that  the  temperature  of  the  rectum  is  a  little  lower  than  that  of 
the  blood,  and  as  the  ear  is  gorged  with  that  fluid,  it  is  easy  to  understand  why 
it  should  possess  its  temperature.  Many  facts  prove  that  the  degree  of  tempera- 
ture and  sensibility  in  a  part  are  in  direct  ratio  with  the  amount  of  blood  circu- 
lating in  it. 

If  galvanism  be  applied  to  the  superior  portion  of  the  sympathetic  nerve  after 
it  has  been  cut  in  the  neck,  the  vessels  of  the  face  and  ear,  after  a  short  time, 
begin  to  contract,  and  subsequently  resume  their  normal  condition,  if  they  do 
not  even  diminish.  Coincidently  with  this  diminution,  there  is  a  decrease  of 
the  temperature  and  sensibility  of  the  face  and  ear,  until  the  palsied  and  sound 
side  are  alike  in  this  respect. 

When  the  galvanic  current  ceases  to  act,  the  vessels  again  dilate,  and  all  the 
phenomena  discovered  by  M.  Bernard  reappear.  It  hence  appears  that  the  only 
direct  effect  of  section  of  the  cervical  portion  of  the  sympathetic  is  the  paralysis 
and  consequent  dilatation  of  the  blood-vessels.  Another  deduction  from  these 
experiments  is,  that  the  sympathetic  sends  motor  fibres  to  many  of  the  blood- 
vessels of  the  head.1  The  same  phenomena  of  elevation  of  temperature  may  be 
produced  by  suspending  an  animal  with  the  head  downwards,  and  thus  facilitating 
the  flow  of  blood  to  that  extremity. — ED.] 

440.  The  influence  which  conditions  of  the  Nervous  System  are  thus  shown  to 
possess  over  the  function  of  Calorification,  has  led  some  Physiologists  and  even 
Chemists  to  the  conclusion,  that  the  production  of  Heat  is  essentially  dependent 
upon  Nervous  agency,  of  which  it  is  one  of  the  manifestations.  But,  as  Prof. 
Liebig  justly  observes,  "if  this  view  exclude  chemical  action,  or  changes  in  the 
arrangement  of  the  elementary  particles,  as  a  condition  of  nervous  agency,  it 
means  nothing  else  than  to  derive  the  presence  of  motion,  the  manifestation  of 
force,  from  nothing.  But  no  force,  no  power,  can  come  of  nothing."  2  That  the 
production  of  heat  in  living  bodies  may  take  place  without  any  possible  assistance 
from  Nervous  agency,  is  manifest  from  the  phenomena  of  Vegetable  heat  (See 
PRINC.  OF  COMP.  PHYS.,  §  439,  Am.  Ed.) ;  and  there  can  be  no  reasonable  doubt 
that  the  source  of  this  production  is  a  true  combustive  process.  And  the  evidence 
afforded  by  the  post-mortem  production  of  heat  in  the  Human  subject  (§  428) 
conclusively  points  to  the  same  result ;  more  particularly  as  the  elevation  of  tem- 
perature observed  in  the  brain  was  uniformly  less  than  than  which  was  mani- 
fested in  other  large  organs. — But  the  phenomena  just  enumerated  (and  many 
others  that  might  be  cited)  can  scarcely  be  accounted-for,  without  admitting  thai 
the  Nervous  system  exerts  an  important  modifying  power  upon  the  temperature 
of  the  body,  which  may  be  either  elevated  or  depressed  through  its  agency ;  and 
the  question  now  arises,  whether  this  operation  takes  place  through  the  influence 
1  Vide  Phil.  Med.  Exam.,  N.  S.,  rol.  viii.  No.  viii.,  August,  1852. 
1  "Animal  Chemistry,"  3rd  edit.,  p.  39. 

27 


41 3  EVOLUTION   OF   HEAT,    LIGHT,    AND   ELECTRICITY. 

which  the  Nervous  system  exerts  over  the  molecular  processes  of  Nutrition,  Se- 
cretion, &c.,  or  through  some  more  direct  method.  It  can  scarcely  be  denied 
that  the  first  of  these  channels  affords  not  merely  a  possible,  but  also  a  probable 
means  for  the  exercise  of  such  influence;  but  still  it  is  difficult  to  conceive  that 
any  great  effect  can  be  thus  produced,  since,  as  already  shown,  it  is  not  so  much 
in  the  growth  as  in  the  disintegration  of  textures,  that  heat  is  produced  by  the 
oxidation  of  their  components.  On  the  other  hand,  from  the  close  relation  which 
exists  between  the  Vital  and  the  Physical  forces  (See  PRINC.  or  GEN.  PHYS.,  Am. 
Ed.),  it  can  scarcely  be  regarded  as  improbable  that  the  Nervous  force,  generated 
by  molecular  changes  in  the  Nervous  substance,  may  manifest  itself  under  the 
form  of  Heat,  just  as  we  know  that  it  manifests  itself  (in  the  electric  Fishes,  &c.) 
under  that  of  Electricity.1  And  thus  it  is  quite  conceivable,  that  one  mode  in 
which  alimentary  materials  may  be  applied  to  the  maintenance  of  Animal  Heat, 
may  consist  in  their  subservience  to  these  molecular  changes,  which  seem  to  take 
place  in  the  Nervous  substance  with  more  activity  than  in  any  other  tissue ;  and 
thus  a  large  measure  of  caloric  may  be  generated  through  the  immediate  instru- 
mentality of  the  Nervous  system,  notwithstanding  that  the  ultimate  source  of  its 
development  lies  (as  in  the  Chemical  theory)  in  the  oxidation  of  the  elements  of 
the  food. — Such  an  hypothesis  will  be  found  consistent,  the  Author  believes, 
with  all  the  well-ascertained  facts  of  the  case  '}  for  whilst  it  assigns  their  full 
value  to  all  those  proofs,  which  establish  (in  his  mind)  the  necessary  dependence 
of  Calorification  upon  the  changes  to  which  the  Respiration  is  subservient;  and 
thus  upon  the  supply  of  combustive  material  on  the  one  hand  and  of  oxygen  on 
the  other,  it  also  assigns  a  definite  modus  operandi  to  the  Nervous  system,  as  an 
instrument  largely  concerned  in  the  production  and  distribution  of  the  heat  thus 
generated, — this  modus  operandi,  moreover,  being  in  such  complete  harmony 
with  the  other  manifestations  of  Nervous  power,  that  its  existence  might  almost 
have  been  predicated  upon  general  considerations.2 

441.  We  have  now  to  inquire  whether  the  power  of  generating  Heat  is  pos- 
sessed by  the  Human  subject  in  an  equal  degree  at  all  ages ;  this  question  being 
very  different  from  that  of  the  ordinary  temperature  of  the  body  at  the  various 
periods  of  life  j  since  an  individual  who  can  maintain  a  high  temperature  when 
the  surrounding  air  is  moderately  warm,  may  have  very  little  power  of  bearing 
continued  exposure  to  severe  cold.  Important  analogical  evidence  on  this  point 
has  been  supplied  by  the  experiments  of  Dr.  W.  F.  Edwards  upon  the  lower 
Mammalia,  Birds,  &c.3  It  appears  from  these  to  be  a  general  fact,  that,  the 
younger  the  animal,  the  less  is  its  independent  calorifying  power.  Thus  the 
development  of  the  embryo  of  all  Oviparous  animals  is  entirely  dependent  upon 
the  amount  of  external  warmth  supplied  to  it.  There  are  many  kinds  of  Birds, 
which,  at  the  time  they  issue  from  the  egg,  are  so  deficient  in  the  power  of  gene- 
rating heat,  that  their  temperature  rapidly  falls  when  they  are  removed  from  the 
nest  and  placed  in  a  cold  atmosphere ;  it  being  shown  by  collateral  experiments, 
that  the  loss  of  heat  was  not  to  be  attributed  to  the  absence  of  feathers,  nor  to 
the  extent  of  surface  exposed  in  comparison  with  the  bulk  of  the  body ;  and  that 
nothing  but  an  absolute  deficiency  in  the  power  of  generating  it,  would  account 
for  the  fall  of  temperature.  This  is  quite  conformable  to  facts  well  ascertained 
in  regard  to  Mammalia.  The  foetus,  during  intra-uterine  life,  has  little  power 
of  keeping-up  its  own  temperature ;  and  in  many  cases  it  is  much  dependent  on 
external  warmth,  for  some  time  after  birth.  The  degree  of  this  dependence, 
however,  differs  greatly  in  the  various  species  of  Mammalia,  as  among  Birds ; 
being  less,  in  proportion  as  the  general  development  is  advanced.  Thus,  young 
Guinea-pigs,  which  can  run-about  and  pick-up  food  for  themselves,  almost  as 

See  "  Princ.  of  Com.  Phys.,"  Am.  Ed.,  \\  461-466. 

2  See  the  Author's  Memoir  «  On  the  Mutual  Relations  of  the  Vital  and  Physical  Forces,' 
fr.  »  Phil.  Trans.,"  1850. 
'  "  On  the  Influence  of  Physical  Agents  on  Life,"  part  iii.  chap.  i. 


EVOLUTION    OF    HEAT. 


419 


soon  as  they  are  born,  are  from  the  first  independent  of  parental  warmth;  whilst 
on  the  other  hand,  the  young  of  Dogs,  Cats,  Rabbits,  &c.,  which  are  born  blind, 
and  which  do  not,  for  a  fortnight  or  more,  acquire  the  same  development  with 
the  preceding,  rapidly  lose  their  heat  when  withdrawn  from  contact  with  the 
body  of  the  mother. 

442.  In  the  Human  species,  it  is  well  known  that  external  warmth  is  neces- 
sary for  the  Infant,  its  body  rapidly  losing  heat  when  exposed  to  the  chilling  in- 
fluence of  a  low  temperature ;  but  the  fact  is  too  often  neglected  (under  the 
erroneous  idea  of  '  hardening '  the  constitution)  during  the  early  years  of  child- 
hood.    It  is  to  be  carefully  remembered,  that  the  development  of  Man  is  slower 
than  that  of  any  other  animal,  and  that  his  calorifying  power  is  closely  connected 
with  his  general  bodily  vigour;  and  though  the  infant  becomes  more  independent 
of  it  as  development  advances,  it  is  many  years  before  the  standard  can  be  main- 
tained without  assistance,  throughout  the  ordinary  vicissitudes  of  external  tem- 
perature.    Especial  care   is  required  with  regard  to  the  maintenance   of  the 
bodily  heat  by  artificial  warmth,  in  the  case  of  children  prematurely  born ;  for 
the  earlier  the  period  of  embryonic  life,  the  less  is  the  power  of  calorification 
that  exists  for  some  time  after  birth.     The  temperature  of  a  seven  months' 
child,  though  well  swathed  and  near  a  good  fire,  was  found  by  Dr.  W.  Edwards, 
within  two  or  three  hours  after  its  birth,  to  be  no  more  than  89-6°.     And  in 
some  of  the  recorded  instances  in  which  the  birth  has  taken  place  before  the 
completion  of  the  sixth  month,  it  has  not  been  found  possible  to  maintain  the 
warmth  of  the  infant  by  exposure  to  the  radiant  heat  of  a  fire,  the  contact  of  the 
warm  body  of  another  person  being  the  only  effectual  means  of  keeping  up  its 
temperature.  —  The  fullest  measure  of  calorifying  power  is  possessed  by  adults; 
but  even  in  them  it  is  sometimes  weakened  by  previous  exertion,  so  that  death 
by  the  cooling  of  the  body  may  occur,  when  the  body  is  exposed  to  cold  of  no 
great  intensity,  but  in  a  state  of  exhaustion  of  nervous  power;  a  fact  which  re- 
markably confirms  the  views  advanced  in  the  preceding  paragraph.     A  decrease 
of  calorifying  power  takes  place  in  advanced  age.     Old  people  complain  that  their 
"  blood  is  chill ;"  and  they  suffer  greatly  from  exposure  to  cold,  the  temperature 
of  the  whole  body  being  lowered  by  it. 

443.  These  facts  have  a  very  interesting  connection  with  the  results  of  statis- 
tical inquiries,  as  to  the  average  number  of  deaths  at  different  seasons;  the  fol- 
lowing are  recorded  by  M.  Quetelet,1  as  occurring  at  Brussels,  the  mean  monthly 
mortality  at  each  age  being  reckoned  as  100. 


First 
Month. 

2—3 

Tears. 

8-12 
Years. 

25—30 
Years. 

50—65 
Years. 

90  Years 
and  above. 

January     

1-39 

1-22 

1-08 

1-05 

1-30 

1-58 

1-28 

1-18 

1-06 

1-04 

1-22 

1-48 

1-21 

1-30 

1-27 

1-11 

1-11 

1-25 

April    ...       

1-02 

1-27 

1-34 

1-06 

1-02 

0-96 

0-93 

1-12 

1-21 

1-02 

0-93 

0-84 

0-83 

0-94 

0-99 

1-02 

0-85 

0-75 

JUly  

0-78 

0-82 

0-88 

0-91 

0-77 

0-64 

0-79 

0-73 

0-82 

0-96 

0-85 

0-66 

September       

0-86 

0-76 

0-81 

0-95 

0-89 

0-76 

October   

0-91 

0-78 

0-76 

0-93 

0-90 

0-74 

0-93 

0-91 

0-80 

0-97 

1-00 

1-03 

December   

1-07 

1-01 

0-96 

0-97 

1-16 

1-29 

We  see  from  this  table  that,  during  the  first  months  of  infant  life,  the  external 
temperature  has  a  very  marked  influence ;  for  the  average  mortality  during  each 
of  the  three  summer  months  being  80,  that  of  January  is  nearly  140,  and  the 
average  of  February  and  March  is  125.  This  is  confirmed  by  the  result  obtained 
1  "  Essai  de  Physique  Sociale,"  torn.  i.  p.  197. 


420 

by  MM.  ViHerine*  and  Milne-Edwards,  in  their  researches  on  the  mortality  of 
the  children  conveyed  to  the  Foundling  Hospitals  in  the  different  towns  in 
France ;  for  they  not  only  ascertained  that  the  mortality  is  much  the  greatest 
during  the  first  three  months  in  the  year,  but  also  that  it  varies  in  different  parts 
of  the  kingdom,  according  to  the  relative  severity  of  the  winter.1  As  childhood 
advances,  however,  the  winter  mortality  diminishes,  whilst  that  of  the  spring 
undergoes  an  increase ;  this  is  probably  due  to  the  greater  prevalence  of  certain 
epidemics  at  the  latter  season ;  for  the  same  condition  is  observed,  in  a  still  more 
remarkable  degree,  between  the  ages  of  8  and  12  years, — the  time  when  children v 
are  most  severely  affected  by  such  epidemics.  As  the  constitution  acquires 
greater  vigour,  and  the  bodily  structure  attains  its  full  development,  the  influence 
of  the  season  upon  mortality  becomes  less  apparent ;  so  that  at  the  age  of  from 
25  to  30  years,  the  difference  between  the  summer  and  winter  mortality  is  very 
slight.  The  difference  reappears,  however,  in  a  very  marked  degree,  at  a  later 
period,  when  the  general  vigour,  and  the  calorifying  power,  undergo  a  gradual 
diminution.  Between  the  ages  of  50  and  65,  it  is  nearly  as  great  as  in  early 
infancy;  and  it  gradually  becomes  more  striking,  until,  at  the  age  of  90  and 
upwards,  the  deaths  in  January  are  158,  for  every  74  in  July  (a  proportion  of  2^ 
to  1);  and  the  average  of  the  three  winter  months  is  145,  whilst  that  of  the 
three  summer  months  is  only  68,  or  less  than  one-half. — The  results  of  the  com- 
parisons which  have  now  been  carried-out  for  many  successive  years,  in  the 
Reports  of  the  Registrar  General,  between  the  variations  in  the  weekly  rate  of 
mortality  in  the  Metropolis  and  the  range  of  atmospheric  temperature,  present  a 
close  coincidence  with  the  foregoing:  it  being  especially  to  be  noted,  that  the 
rate  of  mortality  (save  during  the  prevalence  of  any  fatal  epidemic)  is  almost 
invariably  the  highest  during  the  winter  months ;  that  the  increase  of  deaths  at 
that  period  is  most  marked  amongst  children  and  old  people ;  and  that  any  ex- 
traordinary severity  of  winter  cold  constantly  produces  a  great  augmentation  in 
the  mortality,  the  weekly  number  of  deaths  rising  from  the  average  of  1000  (or 
thereabouts)  to  1200,  when  the  mean  temperature  of  the  twenty-four  hours 
remains  a  degree  or  two  below  the  freezing-point. 

444.  Having  thus  considered  the  means  by  which  the  degree  of  Heat,  neces- 
sary for  the  performance  of  the  functions  of  the  Human  system,  is  generated, 
we  have  to  inquire  how  its  temperature  is  prevented  from  being  raised  too  high, 
in  other  words,  what  frigorifying  means  there  are,  to  counterbalance  the  influence 
of  causes,  which  in  excess  would  otherwise  be  fatal,  by  raising  the  heat  of  the 
body  to  an  undue  degree  (§  430).  How  is  it,  for  example,  that,  when  a  person 
enters  a  room  whose  atmosphere  is  heated  to  one  or  two  hundred  degrees  above 
his  body,  the  latter  does  not  partake  of  the  elevation,  even  though  exposed  to 
the  heat  for  some  time  ?  Or,  since  the  inhabitants  of  a  climate,  where  the  ther- 
mometer averages  100°  for  many  weeks  together,  are  continually  generating 
additional  heat  in  their  own  bodies,  how  is  it  that  this  does  not  accumulate,  and 
raise  them  to  an  undue  elevation  ? — The  means  provided  by  Nature  for  cooling 
the  body  when  necessary,  are  of  the  simplest  possible  character.  From  the  whole 
of  its  soft  moist  surface,  simple  Evaporation  will  take  place  at  all  times,  as  from 
an  inorganic  body  in  the  same  circumstances ;  and  the  amount  of  this  will  be 
regulated  merely  by  the  condition  of  the  atmosphere,  as  to  warmth  and  dryness. 
The  more  readily  watery  vapour  can  be  dissolved  in  atmospheric  air,  the  more 
will  be  lost  from  the  surface  of  the  body  in  this  manner.  In  cold  weather,  very 

1  Dr.  Emerson  has  shown  that,  in  the  Southern  and  Middle  States  of  North  America, 
the  high  summer  temperature  is  the  greatest  cause  of  Infant-mortality ;  the  proportion  of 
deaths  during  the  first  year  of  childhood,  occurring  in  the  months  of  June,  July,  and  August, 
being  about  four  times  greater  than  that  occurring  during  the  same  months  in  any  subse- 
quent year  up  to  the  age  of  20.  The  winter  mortality  Tinder  the  second  year  scarcely 
exceeds  the  average  of  subsequent  years.  (*<  Amer.  Jour,  of  Med.  Sci.,"  Nov.,  1831). 


EVOLUTION     OF    LIGHT.  421 

little  is  thus  carried-off,  even  though  the  air  be  dry:  and  a  warm  atmosphere, 
already  charged  with  dampness,  will  be  nearly  as  ineffectual.  But  simple  evapo- 
ration is  not  the  chief  means  by  which  the  temperature  of  the  body  is  regulated. 
The  Skin,  as  already  mentioned  (§  421),  contains  a  large  number  of  glandulse,  ' 
the  office  of  which  is  to  secrete  an  aqueous  fluid ;  and  the  amount  of  this  Exha- 
lation appears  to  depend  solely  or  chiefly  upon  the  temperature  of  the  surround- 
ing air.  Thus,  when  the  external  heat  is  very  great,  a  considerable  amount  of 
fluid  is  transuded  from  the  skin;  and  this,  in  evaporating,  carries-off  a  large 
quantity  of  the  free  caloric,  which  would  otherwise  raise  the  temperature  of  the 
body.  If  the  atmosphere  be  hot  and  dry,  and  also  be  in  motion,  both  exhala- 
tion and  evaporation  go-on  with  great  rapidity.  If  it  be  cold,  both  are  checked, 
the  former  almost  entirely  so;  but,  if  it  be  dry,  some  evaporation  still  continues. 
On  the  other  hand,  in  a  hot  atmosphere,  saturated  with  moisture,  exhalation 
continues,  though  evaporation  is  almost  entirely  checked ;  and  the  fluid  poured- 
out  by  the  exhalant  glands  accumulates  on  the  skin.  There  is  reason  to  believe 
that  the  secretion  continues,  even  when  the  body  is  immersed  in  water,  provided 
its  temperature  be  high. — We  learn  from  these  facts  the  great  importance  of  not 
suddenly  checking  Exhalation,  by  exposure  of  the  surface  to  cold,  when  the 
secretion  is  being  actively  performed ;  since  a  great  disturbance  of  the  circula- 
tion will  be  likely  to  ensue,  similar  to  that  which  has  been  already  mentioned, 
as  occurring  when  other  important  secretions  are  suddenly  suspended. 

3.  Evolution  of  Light. 

445.  Although  the  evolution  of  Light  from  the  living  Human  subject  is  an 
exceptional  phenomenon,  which  has  only  been  observed  in  morbid  states  of  the 
body,  yet  its  occasional  occurrence  is  fraught  with  interest  to  the  Physiologist,  on 
the  one  hand  from  its  relation  to  the  Luminosity  so  common  among  the  lower 
animals,  and  on  the  other  from  the  indications  which  it  affords  of  the  possibility 
of  the  formation,  even  during  life,  of  peculiar  phosphuretted  compounds,  which, 
being  products  of  incipient  decomposition,  have  been  usually  supposed  to  be  ge- 
nerated only  after  death. — There  is  no  doubt  that  luminous  exhalations  frequently 
ascend  from  burial-grounds ;  and  that  the  superstitions  of  many  nations  respect- 
ing  '  corpse-lights '  have  to  this  extent  a  foundation  in  fact.  A  very  decided 
luminosity  has  been  observed  to  proceed  from  dissecting-room  subjects,  the  lighl 
thus  evolved  being  sufficient  to  render  the  forms  of  the  bodies,  as  well  as  those 
of  muscles  and  other  dissected  parts  (which  are  peculiarly  bright),  almost  as  dis- 
tinct as  in  the  daylight.  That  this  proceeds  from  the  production  of  a  peculiai 
phosphorescent  compound,  is  shown  by -the  fact,  that  the  luminosity  may  be  com- 
municated to  the  fingers  or  to  towels,  &c.,  by  contact  with  the  luminous  sur- 
faces.1— Dr.  W.  Stokes  narrates  the  case  of  a  patient  who  was  under  his  observa- 
tion, some  years  since,  in  the  Old  Meath  Hospital,  having  been  admitted  on  ac- 
count of  an  enormous  cancer  in  her  breast,  which  was  in  an  advanced  state  of 
ulceration,  the  edges  being  irregular  and  everted;  every  part  of  the  base  and 
edges  of  this  cavity  was  strongly  phosphorescent,  the  light  being  sufficient  to 
enable  the  figures  on  a  watch-dial  to  be  distinguished  within  a  few  inches ;  and 
here  also  it  appeared  that  the  luminosity  was  due  to  a  particular  exudation  from 
the  exposed  surface.  Three  cases  are  recorded  by  Sir  H.  Marsh,  in  which  an 
evolution  of  light  took-place  from  the  living  body,  without  any  such  obvious 
source  of  decomposition ;  all  the  subjects  of  these  cases,  however,  were  in  the  last 
stages  of  phthisis;  and  it  can  scarcely  be  doubted  that  here,  as  in  other  diseases 

1  See  Sir  Herbert  Marsh  on  "  The  Evolution  of  Light  from  the  Living  Human  Subject," 
(Dublin,  1842),  p.  20.— From  this  interesting  pamphlet,  most  of  the  statecraft,  i:i  'Ms 
paragraph  are  derived. 


422  EVOLUTION   OF    HEAT,    LIGHT,    AND    ELECTRICITY. 

of  exhaustion,  incipient  disintegration  was  taking-place  during  the  later  periods 
of  life  (§  72).  The  light  in  each  case  is  described  as  playing  around  the  face, 
but  not  as  directly  proceeding  from  the  surface ;  and  in  one  of  these  instance^, 
which  was  recorded  by  Dr.  D.  Donovan,1  not  only  was  the  luminous  appearance 
perceptible  over  the  head  of  the  patient's  bed,  but  luminous  vapours  passed  in 
streams  through  the  apartment.  It  can  scarcely  be  doubted  that  it  was  here  the 
breath,  which  contained  the  luminous  compound,  more  especially  as  it  was  ob- 
served in  one  of  the  cases  to  have  a  very  peculiar  smell ;  and  the  probability  that 
the  luminosity  was  due  to  the  presence  of  phosphorus  in  progress  of  slow  oxida- 
tion, is  greatly  increased  by  the  fact  already  referred- to  (§  322),  that  the  injec- 
tion of  phosphuretted  oil  into  the  blood-vessels  gives-rise  to  a  similar  appearance. 
In  repeating  this  experiment,  Sir  H.  Marsh  states  that  when  half  an  ounce  of 
olive-oil,  holding  two  grains  of  phosphorus  in  solution,  was  injected  into  the  cru- 
ral vein  of  a  dog,  a  dense  .white  vapour  began  to  issue  from  the  nostrils  even  be- 
fore the  syringe  was  completely  emptied,  which  became  faintly  luminous  on  the 
removal  of  the  lights  :  and  the  injection  being  repeated  with  the  same  quantity, 
the  expiration  immediately  became  beautifully  luminous,  resembling  jets  of  pale- 
coloured  flame  pouring-forth  from  the  nostrils  of  the  animal.  And  the  luminosity 
which  has  been  occasionally  observed  in  the  urine,2  may  fairly  be  imputed  to  an 
increase  in  the  quantity  of  unoxidized  phosphorus  which  it  seems  normally  to 
contain  (§  413) ;  its  liberation  taking-place  at  a  more  rapid  rate  than  its  conver- 
sion into  phosphoric  acid  (§  414),  either  through  excessive  excretion  or  through 
impeded  respiration.3  A  case  has  been  recorded  by  Raster  (loc.  cit.)  in  which 
the  body-linen  was  rendered  luminous  by  the  perspiration,  after  any  violent  ex- 
ercise j  and  here,  too,  the  cause  may  be  presumed  to  have  been  the  same. — On 
the  whole,  then,  we  may  conclude  the  occasional  evolution  of  Light  from  the  Hu- 
man subject,  to  be  the  consequence  (when  not  an  electrical  phenomenon)  of  the 
production  of  a  phosphorescent  compound  at  the  expense  of  the  disintegrating 
tissues ;  which  compound  passes-off  through  one  of  the  ordinary  channels  of 
excretion. 

4.  Evolution  of  Electricity. 

446.  When  the  vast  variety  of  changes  of  condition  to  which  the  components 
of  the  living  body  are  subjected  during  the  performance  of  its  vital  operations, 
and  the  impossibility  of  the  occurrence  of  any  of  these  without  some  disturbance 
of  Electric  equilibrium,4  are  duly  considered,  the  wonder  is,  not  that  such  dis- 

1  "Dublin  Medical  Press,"  Jan.  15,  1840. 

""Casper's  Wochenschrift,"  1849,  No.  15. — A  case  has  been  recently  put  on  record 
(Buchner's  Repert.  B.  viii.  p.  342),  in  which  the  urine  and  semen  of  a  patient  who  was 
under  treatment  for  impotence  and  spermatorrhoea,  and  who  was  employing  phosphorus  as 
a  remedy  both  internally  and  externally,  were  observed  to  be  luminous. 

3  The  large  proportion  of  intemperate  subjects,  among  those  who  exhibit  this  phenome- 
non, seems  to  confirm  the  view  already  expressed,  that  the  habitual  presence  of  Alcohol 
in  the  blood  interferes  with  the  oxidation  and  elimination  of  excrementitious  matters. 

4  There  is  probably  no  instance  of  chemical  union  or  decomposition,  in  which  the  electric 
condition  of  the  bodies  concerned  is  not  altered.     Simple  change  of  form,  from  solid  to 
liquid,  or  from  liquid  to  gaseous,  is  attended  with  electric  disturbance ;  and  this  is  greatly 
increased  when  any  separation  takes  place  between  substances  that  were  previously  united, 
as  when  water  containing  a  small  quantity  of  saline  matter  is  caused  to  evaporate  and  to 
leave  it  behind.     Heat,  again,  is  continually  generating  Electricity;  for  not  only  is  a  cur- 
rent produced  by  the  heating  of  two  dissimilar  metals  in  contact,  but  also  by  the  unequal 
heating  of  two  parts  of  the  same  bar  ;  and  though  the  effect  is  most  striking  in  the  case  of 
metals,  it  is  by  no  means  limited  to  them.     And  so  constantly  is  Electricity  generated  by 
the  retardation  of  motion,  as  in  friction,  that  it  is  not  possible  to  rub-together  any  two 
substances,  excepting  those  which  are  of  the  most  perfect  homogeneity  (such  as  the  frac- 
tured surfaces  M;  a  broken-bar),  without  the  production  of  Electric  change,  as  well  as  of 
Heat. 


EVOLUTION    OF    ELECTRICITY.  423 

turbance  should  be  occasionally  so  considerable  as  to  make  itself  apparent,  but 
that  it  should  be  ordinarily  so  obscure  as  only  to  be  detected  by  the  most  careful 
search,  and  with  the  assistance  of  the  most  delicate  instruments.  The  researches 
of  Prof.  Matteucci,  M.  du  Bois-Reymond,  and  others,  however,  have  now  made 
it  apparent,  that  there  are  no  two  parts  of  the  body  (save  those  which  correspond 
on  the  opposite  sides),  whose  electrical  condition  is  precisely  the  same ;  and  that 
the  differences  between  them  are  greater  in  proportion  to  the  diversity  of  the 
vital  processes  which  are  taking-place  in  them,  and  to  the  activity  with  which 
these  are  being  carried-on.1 — It  is  by  the  comparison  of  the  electric  states  of  dif- 
ferent Secreting  surfaces,  that  such  departures  from  equilibrium  are  most  readily 
demonstrated.  Thus,  Donne  found  that  the  skin  and  most  of  the  internal  mem- 
branes are  in  opposite  electrical  states;  and  Matteucci  observed  a  considerable 
deflection  of  the  needle  of  a  delicate  galvanometer,  when  the  liver  and  stomach 
of  a  rabbit  were  connected  with  its  platinum  electrodes.2  More  recently,  Mr. 
Baxter  has  found  that  if  one  of  the  electrodes  be  placed  upon  any  part  of  the 
intestinal  surface,  and  the.  other  be  inserted  into  the  branch  of  the  mesenteric 
vein  proceeding  from  it,  a  decided  deflection  of  the  needle  was  produced,  indi- 
cating a  positive  condition  of  the  blood ;  but  that  no  effect  was  produced,  when 
the  second  electrode  was  inserted  into  the  artery  of  the  part,  instead  of  into  its 
vein.  These  effects  were  found  to  cease  after  the  death  of  the  animals;  and  could 
not  be  attributed,  therefore;  to  mere  chemical  differences  between  the  blood  and 
the  secreted  product;  but  must  have  arisen  from  electric  disturbance  taking-place 
in  the  very  act  of  secretion.3 — That  the  process  of  Nutrition,  as  well  as  of  Secre- 
tion, in  parts  which  are  undergoing  rapid  molecular  change,  gives-rise  to  electric 
disturbance,  is  proved  by  the  experiments  of  Matteucci  and  du  Bois-Reymond, 
upon  the  relative  electrical  states  of  different  parts  of  muscles  and  nerves.  If 
the  two  extremities  of  a  Muscle,  removed  from  the  body  of  an  animal  very 
recently  killed,  be  applied  to  the  two  electrodes  of  a  delicate  galvanometer,  there 
is  usually  some  deflection  of  the  needle ;  this  being  greater,  in  proportion  to  the 
difference  in  the  arrangement  of  the  muscular  and  tendinous  elements  at  the  two 
extremities.  Although  the  direction  of  the  current  is  constant  for  each  muscle, 
yet  there  is  no  constant  relation  between  the  direction  of  the  currents  and  the 
position  of  the  muscles  in  the  body ;  thus  in  the  gastrocnemius  of  the  Frog's  leg, 
the  direction  is  from  the  foot  towards  the  body,  whilst  in  the  sartorius  it  is  the 
reverse.  Taking  all  the  muscles  of  a  part  together,  however,  there  is  usually 
such  a  want  of  balance  between  the  opposite  currents,  that  a  constant  current  is 
established  in  the  direction  of  the  strongest  and  most  numerous  of  the  separate 
muscular  currents;  this,  in  the  Frog,  passes  uniformly  from  the  hind-feet  towards 
the  head,  and  was  at  one  time  supposed  to  be  peculiar  to  that  animal;  but  a  simi- 
lar current  may  almost  always  be  detected  in  other  animals.  The  muscular  cur- 
rent grows  feebler  and  feebler,  the  longer  the  muscle  has  been  removed  from  the 
body;  it  is  affected  by  any  agents  which  tend  to  lower  its  vitality,  and  becomes 
extinct  as  soon  as  its  contractility  ceases.  From  the  experiments  of  M.  du  Bois- 
Reymond,  to  be  presently  described  (§  450),  it  may  be  concluded  that  the  cur- 
rent in  the  arm  of  Man,  when  at  rest,  is  from  the  shoulder  towards  the  points  of 
the  fingers. 

447.  The  conditions  of  the  l Muscular  current'  have  been  made  the  subject  ol 
special  investigation  by  M.  du  Bois-Reymond ;  and  the  following  is  an  outline  of 

1  Having  had  an  opportunity  of  witnessing  some  of  the  experiments  made  by  M.  du  Bois 
Reymond  with  a  magneto-electrometer  of  extraordinary  sensitiveness,  the  Author  can  bear 
his  personal  testimony  to  the  fact,  that  the  electricity  even  of  the  corresponding  fingers  of 
the  two  hands  is  very  seldom  equally  balanced,  and  that  the  existence  of  even  the  slight- 
est scratch  or  abrasion  of  surface  upon  one  of  them  produces  a  very  marked  disturbance 

1  See  M.  Becquerel's  "  Traite*  de  I'Eleetricite","  torn.  i.  p.  327,  and  torn.  iv.  p.  300. 
"  Philosophical  Transactions,"  1848,  p.  243. 


424  EVOLUTION    OF    HEAT,    LIGHT,    AND    ELECTRICITY. 

the  results  at  which  he  has  arrived,  for  whose  due  comprehension,  however,  it  is 
requisite  that  the  terms  employed  by  him  should  be  first  defined. — The  entire 
muscle,  being  composed  of  a  mass  of  fibres,  having  a  generally-parallel  direction, 
and  attached  at  their  extremities  to  tendinous  structure  (which  has  in  itself  but 
liule  or  no  electromotor  power,  but  is  a  conductor  of  electricity),  it  follows  that 
tiie  tendon  or  tendinous  portion  of  a  muscle  represents  a  surface  formed  by  the 
Vases  of  the  muscular  fibres  considered  as  prisms,  which  may  be  designated  its 
natural  transverse  section.  On  the  other  hand,  the  fleshy  surface  of  the  muscle, 
which  is  formed  only  by  the  sides  of  the  fibres  considered  as  prisms,  may  be  re- 
garded as  the  natural  longitudinal  section  of  the  muscle.  Again,  if  a  muscle 
be  divided  in  a  direction  more  or  less  perpendicular  to  its  fibres,  an  artificial 
transverse  section  will  be  made ;  whilst  if  the  muscle  be  torn  lengthways  in  the 
direction  of  its  fibres,  an  artificial  longitudinal  section  will  be  made ;  and  these 
artificial  sections  show  the  same  electric  conditions  with  their  corresponding  natu- 
ral sections.  Now  experiments  repeated  in  a  great  variety  of  modes  demonstrate, 
that  every  point  in  the  natural  or  artificial  longitudinal  section  of  a  muscle  is 
positive  in  relation  to  evert/  part  of  its  transverse  section,  whether  natural  or  arti- 
ficial ;  the  most  powerful  influence  on  the  galvanometer  being  produced,  when 
a  portion  of  the  surface  (or  natural  longitudinal  section)  of  a  muscle  is  laid  upon 
one  of  the  electrodes,  and  a  portion  of  the  surface  formed  by  cutting  the  muscle 
across  (or  artificial  transverse  section)  is  placed  against  the  other.  When  the 
two  tendinous  extremities  of  a  muscle  whose  form  is  symmetrical  or  nearly  so, 
are  placed  against  the  electrodes,  the  deflection  of  the  needle  of  the  galvanometer 
is  but  slight;  and  the  same  is  the  case  with  two  transverse  sections  taken  at 
equal  distances  from  the  two  ends  of  the  muscle,  and  also  with  two  points  of  the 
longitudinal  section  which  are  equally  distant  from  the  middle  of  its  length. 
But  if  the  two  points  of  the  longitudinal  section  applied  to  the  electrodes,  be  not 
equally  distant  from  the  centre  of  the  muscle,  then  the  point  which  is  nearest  to 
the  centre  is  positive  to  the  one  which  is  nearest  to  the  end ;  and,  in  like  manner, 
when  the  different  parts  of  the  transverse  section  are  tested  in  regard  to  each 
other,  the  points  lying  nearest  the  surface  of  the  muscle,  are  found  to  be  positive 
to  those  nearest  its  interior.  The  intensity  of  the  current,  however,  between 
any  two  points  in  the  same  section  —  whether  transverse  or  longitudinal  —  is 
always  incomparably  less  than  that  of  the  currents  which  are  obtained  between 
two  points  in  different  sections,  one  in  the  longitudinal  and  the  other  in  the 
transverse. 

448.  These  results  may  be  obtained,  not  merely  with  the  entire  Muscle,  but 
with  insulated  portions  of  it ;  and  even,  as  we  are  assured  by  M.  du  Bois-Rey- 
mond,  with  a  single  primitive  fasiculus.  Hence  it  seems  unquestionable,  that 
every  integral  particle  of  the  muscular  substance  must  be  a  centre  of  electro- 
motor action,  and  must  contain  within  itself  positive  and  negative  elements; 
and  the  variations  both  of  intensity  and  direction  in  the  muscular  current,  under 
certain  circumstances,  are  so  sudden  and  so  extensive,  that  it  appears  impossible 
to  account  for  them  by  any  change  of  larger  heterogeneous  elements,  or  in  any 
other  way  than  by  assuming  corresponding  changes  of  position  in  almost  infinitely 
small  centres  of  action.  It  is  indifferent  what  form  is  assigned  to  these  electro- 
motive molecules ;  but  it  would  seem  that  they  must  have  two  negative  polar 
zones,  and  a  positive  equatorial  zone ;  a  combination  of  such  elements  being 
able  to  produce  all  the  electrical  effects  of  a  muscle  in  a  state  of  rest.  It 
seems  altogether  best  to  suit  the  phenomena,  to  suppose  that  each  of  these 
peripolar  molecules  is  formed  by  the  combination  of  two  dipolar  molecules, 
touching  each  other  by  their  positive  poles,  —  as  in  the  subjoined  table,  which 
represents  a  band  of  four  series,  A,  B,  c,  D,  each  series  containing  four  dipolar 
molecules. 


EVOLUTION    OF    ELECTRICITY. 

I  i 

1   4 


425 


•f 


4- 


-f 


-f 


1} 


449.  The  current  shown  by  the  entire  Muscle,  when  made  to  form  part  of  a 
circuit,  is  only  a  derived  current  produced  by  incomparably  more  intense  currents 
circulating  in  the  interior  of  the  muscles  around  these  ultimate  particles,  and 
will  vary  greatly  in  intensity,  according  to  the  mode  in  which  these  particles  are 
arranged ;  generally  speaking,  however,  it  increases  both  with  the  length  and 
with  the  thickness  of  the  muscle.     There  is,  however,  another  cause  of  a  very 
remarkable  nature,  which  influences  both  its  intensity  and  its  direction ;  this,  ac- 
cording to  M.  du  Bois-Reymond,  is  the  existence  of  a  thin  layer  of  muscular 
substance,  beneath  the  tendinous  expansion,  whose  electromotive  power  is  exactly 
opposite  to  that  of  the  rest,  so  that  its  action  tends  to  reverse  the  general  law  of 
the  muscular  current.     For  when  the  gastrocnemius  of  a  frog  is  placed  between 
the  two  electrodes,  so  as  to  touch  them  only  with  its  tendinous  extremities,  it 
gives  a  weak  upward  current ;  but  if  the  frog  have  been  previously  cooled,  there 
will  probably  be  no  current  at  all ;  or  if  it  have  been  frozen,  there  may  actually 
be  a  current  in  the  opposite  direction.     If,  now,  a  drop  of  any  liquid  capable  of 
corroding  the  muscular  tissue  (such  as  alcohol,  creosote,  acids,  alkaline  solutions, 
&c.),  be  placed  upon  the  aponeurosis  of  the  tendo  Achillis,  the  ordinary  upward 
current  of  the  muscle  is  evolved ;  and  the  same  effect  is  produced  by  completely 
removing  a  thin  layer  of  muscular  substance  at  the  natural  transverse  section. 
This  effect  is  accounted-for  by  M.  du  Bois-Reymond,  on  the  supposition  that  at 
the  tendinous  extremities  of  the  muscular  fibres,  the  linear  series  of  peripolar 
elements  is  terminated  by  a  single  dipolar  element,  whose  positive  pole  is  thus 
free,  instead  of  the  negative  pole  being  so;  and  he  has  shown  that  by  an  appa- 
ratus of  zinc  and  copper  constructed  after  this  plan,  all  the  electric  phenomena 
of  the  muscle  at  rest  may  be  imitated. 

450.  That  a  change  in  the  electric  state  of  a  Muscle  takes  place  in  the  act  of 
contraction,  had  been  ascertained  by  the  experiments  of  Prof.  Matteucci;1  but 
as  he  was  only  able  to  detect  this  by  the  galvanoscopic  frog  ("the  galvanometer 
which  he  employed  not  giving  unquestionable  indications  of  it),  he  was  not  able 
to  determine  its  nature  with  accuracy.     This  has  been  accomplished,  however,  by 
M.  du  Bois-Reymond;  who  has  shown  that  during  contraction  the  muscular  cur- 
rent is  not  increased  (as  supposed  by  Matteucci),  but  is  diminished  and  even 
reduced  to  zero.     In  order  to  exhibit  this  phenomenon  satisfactorily,  it  is  found 
advantageous  to  cause  the  muscle  to  contract  powerfully  or  uninterruptedly  for 
as  long  a  time  as  possible,  that  is,  to  tetanize  it ;  and  this  may  be  effected  by 
acting  violently  on  its  nerve  by  heat,  chemical  agents,  or  a  succession  of  electric 
shocks;  or  by  poisoning  the  animal  with  strychnia.     In  whatever  mode  the  teta- 

1  See  his  successive  Memoirs  in  "  Philos.  Transact.,"  for  1845,  1847,  and  1850.    f 


426  EVOLUTION   OF   HEAT,    LTGET,    AND    ELECTRICITY 

nized  state  is  induced,  the  same  result  follows : — the  needle  of  the  galvanometer 
passes-over  to  the  negative  side.  This,  however,  does  not  indicate  (as  might  be 
at  first  supposed)  the  development  of  a  new  current  during  the  contraction,  in  a 
direction  opposite  to  that  which  prevails  during  rest;  but  it  is  the  consequence 
of  the  '  secondary  polarity ' '  which  is  evolved  in  the  platinum  electrodes,  as  soon 
as  tie  muscular  current  is  dimished ;  the  needle  passing  from  the  positive  to  the 
negative  side,  as  soon  as  the  current  of  the  secondary  polarity  becomes  more 
powerful  than  the  original  muscular  current.  This  negative  deflection  of  tho 
needle  at  the  moment  of  contraction,  is  always  proportionate  to  the  actual  inten- 
sity of  the  current  of  the  muscle  while  at  rest;  and  it  ceases  as  soon  as  the  teta- 
nic contraction  ceases,  after  which  the  muscular  current  gradually  recovers  ita 
previous  intensity. 

451.  Thus,  then,  it  appears  that  the  contraction  of  a  Muscle  is  attended  with 
a  marked  diminution  of  its  electromotive  power  ;  a  fact  which  seems  to  harmo- 
nize well  with  the  general  views  already  adverted-to  in  regard  to  the  '  Correlation 
of  Forces ;'  the  changes  which  operate  to  produce  disturbance  of  electric  equili- 
brium whilst  the  muscle  is  at  rest,  being  concerned  in  the  development  of  motor 
power  when  it  is  thrown  into  contraction.  This  alteration  has  been  demonstrated 
by  M.  du  Bois-Reymond  in  the  living  animal,  after  the  following  manner.  The 
two  feet  of  a  live  frog  were  immersed  in  the  two  connecting  vessels,  but  one  of 
the  legs  was  paralyzed  by  division  of  its  sciatic  plexus ;  the  muscular  currents 
of  the  muscles  of  the  two  limbs  neutralized  each  other,  so  long  as  they  remained 
at  rest ;  but  upon  the  frog  being  poisoned  with  strychnia,  so  that  tetanic  convul- 
sions occurred  in  one  limb  whilst  the  other  remained  motionless,  the  current  in 
the  former  limb  was  weakened,  whilst  that  of  the  other  remained  unaffected,  and 
a  deflection  of  the  needle  took  place,  indicating  an  upward  current  in  the  para- 
lyzed limb  and  a  downward  current  in  the  tetanized  one.  The  same  thing  may 
be  shown  in  the  Human  subject,  by  dipping  the  forefingers  of  the  two  hands 
into  the  two  conducting  vessels  connected  with  the  galvanometer,  so  that  the  two 
arms  are  included  in  opposite  directions  in  the  circuit ;  when  if,  after  the  needle 
(which  usually  undergoes  a  temporary  disturbance  on  their  first  immersion)  has 
come  to  a  state  of  rest,  all  the  muscles  of  one  of  the  arms  be  strongly  and  per- 
manently contracted,  so  as  to  give  them  the  greatest  possible  tension  without 
changing  the  position  of  the  arm,  the  needle  is  instantly  deflected,  always  indi- 
cating a  current  from  the  hand  to  the  shoulder,  that  is,  an  upward  current  in  the 
contracted  arm.  Hence,  according  to  the  explanation  just  given,  the  contracted 
arm  plays  the  part  of  the  negative  metal  in  the  circuit,  in  regard  to  the  arm 
whose  muscles  remain  in  the  state  of  relaxation,  showing  that  the  normal  current 
will  be  a  downward  one. — This  change,  however,  is  so  extremely  slight,  that  a 
very  delicate  galvanometer  is  requisite  to  render  it  perceptible.  Its  intensity 
depends  very  much  on  the  muscular  energy  of  the  experimenter ;  and  even  the 
greater  power  which  the  right  arm  usually  possesses,  becomes  perceptible  in  the 
greater  deflection  of  the  needle  when  it  is  put  in  action.2 

1  When  the  electromotor  body  is  removed,  and  the  two  electrodes  (platinum  plates  im- 
mersed in  a  saturated  solution  of  common  salt),  are  connected  by  some  imperfectly  con- 
necting body,  a  secondary  current  is  manifested  in  the  reverse  direction  to  the  first,  the 
needle  being  deflected  to  the  other  side;  this  is  effected  by  the  electro-chemical  reaction 
of  the  substances -which  the  current  of  animal  electricity  has  evolved  on  the  platinum 
plates  by  means  of  its  electrolytic  action ;  and  its  occurrence  is  often  a  useful  and  valu- 
able confirmation  of  the  first  result,  as  showing  that  the  primary  deflection  really  was  the 
consequence  of  the  presence  of  an  electromotor.  When  the  electromotive  action,  more- 
over, is  very  weak,  it  may  be  made  more  evident  by  reversing  the  position  of  the  electro 
motor,  without  first  replacing  the  connector ;  so  that  the  action  which  it  will  then  exert  in 
the  reverse  direction,  will  be  strengthened  by  the  secondary  current  developed  by  the 
previous  action. 

3  Of  this  very  remarkable  experiment,  which  was  first  made  by  M.  du  Bois-Keymond, 
the  Author  has  himself  (through  that  gentleman's  kindness)  been  a  witness;  and  he  can- 
Hot  entertain  the  least  doubt  as  to  the  genuineness  of  the  phenomenon.  —  The  success  of  M. 


EVOLUTION   OF  ELECTRICITY.  427 

452.  The  discovery  that  an  electric  current  exists  in  Nerves,  the  conditions 
of  which  are  in  most  respects  similar  to  that  of  the  Muscular  current,  is  entirely 
due  to  M.  du  Bois-Reymond.     When  a  small  piece  of  a  nerve-trunk  is  cut-off 
from  the  recently-killed  body,  and  is  so  placed  upon  the  electrodes  that  it  touches 
one  of  them  with  its  surface  (or  natural  longitudinal  section),  and  the  other  with 
its  cut  extremity  (or  artificial  transverse  section),  a  considerable  deflection  of  the 
index  is  produced,  the  direction  of  which  always  indicates  the  passage  of  a  cur- 
rent from  the  interior  to  the  exterior  of  the  nerve-trunk.     It  is  indifferent  in 
regard  to  the  direction  of  the  current,  whether  the  central  or  the  peripheral  cut 
extremity  be  applied  to  the  electrode ;  and  in  fact  the  most  powerful  effect  is 
obtained  by  doubling  the  nerve  in  the  middle,  and  applying  both  transverse  sec- 
tions to  one  electrode,  whilst  the  loop  is  applied  to  the  other.     On  the  other 
hand,  if  the  two  cut  extremities  be  applied  to  the  two  electrodes  respectively,  no 
decided  effect  is  produced ;  and  the  same  neutrality  exists  between   any  two 
points  of  the  surface  of  the  trunk,  equidistant  from  the  middle  of  its  length ; 
but  if  the  points  be  not  equidistant,  then  a  slight  deflection  is  produced,  indica- 
ting that  the  parts  nearer  the  middle  are  positive  to  those  nearer  the  extremities. 
It  has  not  been  found  possible,  owing  to  the  small  size  of  the  nerve-trunks  expe- 
rimented-on,  to  test  in  a  similar  manner  the  relative  state  of  different  points  of 
their  transverse  section ;  but  there  can  be  little  doubt,  from  the  complete  con- 
formity which  exists  in  other  respects  between  the  nervous  and  muscular  cur- 
rents, that  the  same  law  will  be  found  to  prevail  in  this  as  in  the  former  case ; 
namely,  that  the  points  nearer  the  surface  are  positive  to  those  nearer  the  centre. 
There  is  no  difference  between  the  motor  and  the  sensory  nerves  in  regard  to  the 
direction  of  this  current,  the  existence  of  which  has  been  proved  by  M.  du  Bois- 
Reymond,  not  only  by  the  galvanometer,  but  also  by  the  excitement  rf  contrac- 
tions in  the  limb  of  the  galvanoscopic  frog.  —  The  l  nervous  current,'  like  the 
muscular,  must  be  considered  as  derived  from  the  electromotive  action  of  the 
molecules  of  the  nerve ;  and,  for  the  reasons  already  pointed-out,  the  intensity 
of  the  current  in  the  immediate  neighbourhood  of  the  molecules,  may  be  infi- 
nitely greater  than  that  which  is  shown  by  the  galvanometer  to  exist  in  the 
trunk  of  the  nerve. 

453.  We  have  now  to  follow  M.  du  Bois-Eeymond  through  his  investigations 
on  the  change  in  the  condition  of  the  i  nervous  current/ 

whilst  the  nerve  is  in  a  state  of  functional  activity, 
whether  motorial  or  sensorial.  For  the  examination  of 
this,  it  is  desirable  to  induce  a  state  of  continuous 
action  in  the  nerve,  analogous  to  the  tetanic  contraction 
of  muscle }  and  this  condition  in  the  motor  nerve  is 
manifestly  that  which  induces  tetanus  in  its  muscle, 
whilst  in  sensory  nerves  it  is  that  in  which  a  violent 
sensation  is  uninterruptedly  kept-up.  No  means  of  ex- 
citing such  a  state  are  so  certain  and  simple,  as  electric 
currents ;  but  it  is  necessary  in  the  first  place  to  deter- 
mine the  modification  which  these  currents  may  them- 
selves produce  in  the  proper  '  nervous  current/  If  a 
portion  of  nerve-trunk  be  so  placed  (Fig.  120),  that  it 
touches  one  of  the  electrodes  by  its  transverse  section 
(which  may  be  designated  T),  and  the  other  by  its  sur- 
face or  longitudinal  section  (L),  and  a  portion  of  its 
continuation  be  included  in  a  galvanic  circuit,  so  that  a  current  shall  pass  in  thu 

du  Bois-Reymond  in  these  and  similar  investigations,  is  doubtless  due  in  great  part  to  the 
marvellous  sensitiveness  of  the  galvanometer  he  employs,  the  coils  of  which  consist  of 
three  miles  of  wire,  as  well  as  to  the  perfection  of  the  various  arrangements  by  which  he 
is  enabled  to  avoid  or  eliminate  sources  of  error;  but  it  must  be  attributed  in  great  part 
also  to  the  philosophic  method  on  which  his  inquiries  are  planned,  and  to  the  skill  ami 
perseverance  with  which  they  are  carried-out. 


428  EVOLUTION    OF    HEAT,    LIGHT,    AND    ELECTRICITY. 

direction  Z — p,  which  is  the  same  in  its  direction  as  that  between  T — L,  then  the 
intensity  of  the  'nervous  current'  T — L,  as  indicated  by  the  deflection  of  the 
needle  of  the  galvanometer,  will  be  found  to  undergo  an  increase ;  whilst  on  the 
other  hand,  if  the  electric  current  be  passed  in  the  contrary  direction  p — z,  the 
intensity  of  the  '  nervous  current '  T — L,  will  decrease.  —  The  portion  z — p  of 
the  nerve,  which  is  included  in  the  electric  circuit,  is  termed  the  excited  por- 
tion, and  the  current  passed  through  it  is  the  exciting  current;  on  the  other 
hand,  the  portion  T — L  included  between  the  electrodes  of  the  galvanometer,  is 
the  derived  portion ;  and  the  altered  condition  of  this  part,  which  is  produced  by 

the  extraneous  current  (this  current  having 

FlG>  121<  been  experimentally  proved  by  M.  du  Bois- 

Reymond  to  exert  no  influence  of  its  own 
on  the  galvanometer),  is  termed  the  electro- 
tonic  state  of  the  nerve.  When  the  inten- 
sity of  the  '  nervous  current '  is  increased, 
the  nerve  is  said  to  be  in  the  positive  phase 
of  this  electrotonic  state;  and  when  it  is 
diminished,  the  nerve  is  in  the  negative 
phase  of  that  state.  —  By  a  proper  arrange- 
ment, the  same  exciting  current  may  be 
made  to  produce  the  positive  phase  in  one 
part  of  a  nerve-trunk,  and  the  negative 
phase  in  another.  Thus  if  the  two  extremi- 
ties of  a  nerve  (Fig.  121,  p  and  c),  be  so 
connected  with  two  galvanometers,  that  both 

shall  develope  the  l  nervous  current/  and  an  intermediate  portion  be  excited  by 
the  transmission  of  an  electric  current  in  the  direction  z — P,  the  nervous  cur- 
rent in  the  '  derived '  portion  c  will  be  increased  in  intensity,  whilst  that  in  the 
portion  p  will  be  diminished. 

454.  Hence  it  may  be  inferred,  that  when  any  portion  of  the  leugth  of  a 
nerve  is  traversed  by  an  electric  current,  besides  the  usual  electro-motive  action 
of  the  nerve,  a  new  electro-motive  action  takes  place  in  every  point  of  the 
nerve,  by  a  polarization  of  the  electro-motive  elements,  which  action  has  the 
same  direction  as  the  exciting  current  itself;  and  a  current  is  thus  produced  in 
the  ' derived'  portion,  which  is  added  to  the  original  'nervous  current'  at  that 
end  of  the  nerve  at  which  the  direction  of  this  new  current  and  of  the  nervous 
current  coincide,  and  is  subtracted  at  that  end  at  which  the  directions  are 
different.  These  variations  in  the  intensity  of  the  '  nervous  current'  continue  as 
long  as  the  'exciting  current'  lasts,  and  immediately  cease  when  the  circuit  of 
that  current  is  broken.  It  is  to  the  induction  of  the  electrotonic  state  in  the 
nerve  supplying  it,  that  the  contraction  of  a  muscle  is  due,  which  ensues  on  the 
completion  of  the  circuit ;  and  to  the  cessation  of  this  state  that  the  muscular 
contraction  is  due  which  is  consequent  upon  the  interruption  of  the  circuit. 
Hence  the  electrotonic  changes  in  the  condition  of  nerves  may  be  observed  with- 
out previously  dividing  them. — When,  on  the  other  hand,  a  nerve  is  'tetanized' 
by  passing  an  interrupted  and  alternating  current  through  a  portion  of  it,  the 
effect  is,  as  in  the  case  of  muscle,  to  produce  a  diminution  in  its  own  proper 
current ;  the  needles  of  both  galvanometers,  in  the  arrangement  last  described, 
being  deflected  to  the  negative  side,  instead  of  one  going  back  to  zero  and  the 
other  having  its  positive  deflection  increased,  as  happens  when  the  f  excited  por- 
tion' is  subjected  to  a  continuous  and  uniform  current.  The  same  negative 
variation  of  the  nervous  current  has  been  demonstrated  by  M.  du  Bois-Reymond 
in  nerves  tetanized  by  other  means,  as  by  the  use  of  strychnia.  And  the 
phenomena  both  of  the  'electrotonic  state,'  and  of  the  'negative  variation  '  are 
precisely  the  same,  whether  motor  or  sensory  nerves  be  subjected  to  the  experi- 
ment; thus  making  it  appear  that  nerve-force  may  be  transmitted  in  either 
direction  along  each  of  these  orders  of  nerves. 


EVOLUTION    OF    ELECTRICITY.  429 

455.  A   very  remarkable    modification   of   the   ( nervous    current*  has    been 
shown   by  M.   du  Bois-Reymond    to    follow  severe    injuries    of  the    nerve,  by 
mechanical,  chemical,  or  thermal  agencies.     If,  for  instance,  a  piece  of  hot  metal 
be  brought  near  to  the  nerve  without  touching  it,  the  nervous  current  will  be 
seen  to  diminish  rapidly,  and  to  have  its  direction  reversed,  during  which  the 
property  possessed  by  the  nerve  of  conveying  irritation  to  the  muscle,  though 
somewhat  impaired,  will  not  be  destroyed ;  and  if,  while  in  this  abnormal  state, 
the  nerve  be  divided,  every  transverse  section  is  found  neutral  or  positive  to  the 
longitudinal  section,  instead  of  negative.     If  the  nerve-trunk  be  then  placed 
between  muscles,  so  as  to  recover  its  natural  moisture,  it  will  at  the  same  time 
recover  its  usual  electro-motive  power.1 

456.  Some  of  the  most  important  parts  of  the  body  being  thus  in  a  state  of 
constant  disequilibrium  with  regard  to  each  other,  it  is  not  surprising  that  the 
electric  state  of  the  whole  should  be  ordinarily  in  disequilibrium  with  that  of 
surrounding  bodies.     This  difference,  however,  is  usually  prevented  from  mani- 
festing itself,  in  consequence  of  the  restoration  of  the  equilibrium  by  the  free 
contact  which  is  continually  taking-place  between  them ;  and  it  is  for  the  most 
part  only  when  the  Human  body  is  insulated,  that  it  becomes  apparent.     The 
galvanometer  is  then  affected,  however,  by  the  contact  of  one  of  its  electrodes 
with  the  person  insulated,  and  the  other  with  any  neighbouring  uninsulated  body ; 
and  also  by  the  contact  of  the  electrode  with  the  hands  of  two  persons  both 
insulated,  who  join  their  other  hands   together,  a  difference  in  the  electrical 
states  of  the  two  individuals  being  thus  indicated.     The  electricity  of  man  is 
most  frequently  positive,  and  irritable  men  of  sanguine  temperament  have  more 
free  electricity  than  those  of  phlegmatic  character;  the  electricity  of  women  is 
more  frequently  negative  than   that  of  men.     There  are  persons  who  scarcely 
ever  pull-off  articles  of  dress  which  have  been  worn  next  the  skin,  without  sparks 
and  a  crackling  noise  being  produced;    especially  in  dry  weather,  when   the 
electricity  of  the  body  is  retained,  instead  of  being  rapidly  dissipated  as  it  is  by 
a  damp  atmosphere.     The  effect  is  usually  heightened,  if  silk   stockings  and 
other  silken  articles  have  been  worn,  since  these  act  as  insulators.     It  is  doubt- 
less in  part  attributable  to  the  friction  of  the  articles  of  dress  against  each  other 
and  against  the  body ;  but  we  can  scarcely  doubt  that  it  is  partly  due  to  the 
generation  of  electricity  in  the  body  itself,  since  it  bears  no  constant  relation 
to  the  former  of  these  supposed  causes.     Thus  a  Capuchin  friar  is  mentioned  by 
Dr.  Schneider,2  who,  on  removing  his  cowl,  always  found  a  number  of  shining 
crackling  sparks  to  pass  from  his  scalp ;  and  this  phenomenon  continued  still 
perceptible  after  a  three  weeks'  illness. — The  most  remarkable  case  of  the  gene- 
ration of  Electricity  in  the  Human  subject  at  present  known,  was  recorded  some 
years  since  in  America.3     The  subject  of  it,  a  lady,  was  for  many  months  in  an 

1  The  materials  of  several  preceding  paragraphs  have  been  derived  from  the  sketch  of 
M.  du  Bois-Reymond's  researches,  by  Dr.  Bence  Jones  ("  On  Animal  Electricity  ;  being  an 
Abstract  of  the  Discoveries  of  Emil  du  Bois-Reymond").     Having  himself  had  the  oppor- 
tunity of  witnessing  a  considerable  number  of  the  experiments  above  referred  to,  the 
Author  feels  it  due  to  M.  du  Bois-Reymond  to  state,  that  their  results  correspond  so  pre- 
cisely with  his  predictions  in  every  instance,  as  to  prove  that  he  had  acquired  a  thorough 
mastery  over  the  conditions  of  the  phenomena.     And  he  may  mention  the  experimental 
demonstration  of  the  '  nervous  current,'  as  most  fully  satisfactory. — It  may  be  stated 
with  confidence,  that  the  course  of  investigation  which  is  being  followed-out  by  M.  da 
Bois-Reymond,  is  one  pre-eminently  calculated  to  develope  results  of  importance  in  Phy- 
siology ;  and  is  the  only  one  out  of  which  definite  indications  in  regard  to  Therapeutic 
applications  of  Electricity  can  be  expected  to  arise. — A  collection  of  laborious  results  on 
this  last  subject,  entitled  "De  1'Electrisation  localised,  et  de  son  Application  a  la  Physi 
ologie,  a  la  Pathologic,  et  a  la  Therapeutique,"  has  just  been  published  (Parrs,  1855)  bj 
Dr.  Duchenne  of  Boulogne.     See  also  "  Brit  and  For.  Med.-Chir.  Rev.,"  vols.  iii  p.  373. 
and  xv.  p.  138. 

2  "  Casper's  Wochenschrift,"  1849,  No.  15. 

3  •'  American  Journal  of  Medical  Sciences."  January,  1838 


430  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

electric  state  so  different  from  that  of  the  surrounding  bodies,  that  whenever 
she  was  but  slightly  insulated  by  a  carpet  or  other  feebly-conducting  medium, 
sparks  passed  between  her  person  and  any  object  she  approached;  when  most 
favourably  circumstanced,  four  sparks  per  minute  would  pass  from  her  finger  to 
the  brass  ball  of  the  stove  at  the  distance  of  1?  inch.  From  the  pain  which 
accompanied  the  passage  of  the  sparks,  her  condition  was  a  source  of  much  dis- 
comfort to  her.  The  circumstances  which  appeared  most  favourable  to  the 
generation  of  the  electricity,  were  an  atmosphere  of  about  80°,  tranquillity  of 
mind  and  social  enjoyment ;  whilst  a  low  temperature  and  depressing  emotions 
diminished  it  in  a  corresponding  degree.  The  phenomenon  was  first  noticed 
during  the  occurrence  of  an  Aurora  Borealis ;  and  though  its  first  appearance 
was  sudden,  its  departure  was  gradual.  Various  experiments  were  made,  with 
the  view  of  ascertaining  if  the  electricity  was  generated  by  the  friction  of  articles 
of  dress;  but  no  change  in  these  seemed  to  modify  its  intensity. 


CHAPTER  XL 

OF   THE   FUNCTIONS   OP   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 
1. —  General  Summary. 

457.  THE  Nervous  System  of  Man,  like  that  of  all  other  animals,  is  composed 
of  (janylionic  centres  and  nerve-trunks  ;  the  former  being  essentially  composed 
of  *  vesicular  substance,'  made-up  of  cells  which  may  be  spheroidal,  fusiform, 
caudate,  stellate,  or  of  almost  any  variety  of  shape ;  the  latter  consisting  entirely 
of  '  nerve-fibres/  which,  in  their  most  completely-developed  state,  are  tubular 
(See  PRINC.  OF  GEN.  PHYS.,  Am.  Ed.).  All  our  knowledge  of  the  structure 
and  endowments  of  these  two  forms  of  tissue,  renders  it  probable  that  they  bear 
a  complementary  relation  to  each  other;  the  Vesicular  substance  having  for  its 
office  to  originate  changes,  which  it  is  the  function  of  the  Fibrous  to  conduct. 
And  thus,  by  means  of  the  extensive  ramifications  of  the  nerve-trunks,  and  the 
power  of  instantaneous  transmission  which  they  possess,  almost  every  part  of  the 
body  is  brought  into  such  close  relation  with  the  central  Sensorium,  that  impres- 
sions made  even  at  the  points  most  remote  from  it  are  immediately  felt  there  (pro- 
vided the  nervous  communication  be  perfect)  ;  while  the  influence  of  Mental  states 
in  determining  movements,  is  exerted  no  less  speedily  and  surely  upon  the  muscu- 
lar apparatus.  For  the  transmission  of  these  two  sets  of  impressions,  the  '  cen- 
tripetal' and  the  'centrifugal/  two  distinct  sets  of  fibres  are  provided,  neither 
of  which  is  capable  of  taking-on  the  function  of  the  other ;  these  are  termed  re- 
spectively, the  afferent  and  the  efferent.1  Of  the  mode  in  which  the  former  ter- 
minate in  the  central  organs  towards  which  they  pass,  and  in  which  the  latter 
commence  their  course  in  these  same  organs,  no  general  statement  can  as  yet  be 
made ;  but  it  is  quite  certain  that,  in  many  instances  at  least,  there  is  an  abso- 
lute continuity  from  one  form  of  nerve-tissue  to  the  other.  Three  principal 
modes  have  been  ascertained,  in  which  this  may  occur.  Either  a  globular  cell 
may  give-off  a  single  prolongation  that  becomes  a  fibre,  as  seen  at  a,  Fig.  122 ; 
in  which  case  the  cell  is  said  to  be  <  unipolar/  Or  a  ganglion-cell  presents  itself 
(as  it  were)  in  the  course  of  a  nerve-tube,  having  each  of  its  extremities  pro- 
longed into  a  fibre,  as  shown  in  Fig.  123 ;  in  which  case  the  cell  is  said  to  be 
'bipolar.'  The  former  of  these  arrangements  seems  to  be  more  common  in  the 

The  *  afferent '  nerves  are  commonly  designated  sensory ;  but  this  is  not  strictly  cor- 
rect, since  they  frequently  convey  impressions  which  do  not  give  rise  to  sensations.  The 
'  efferent '  nerves,  in  like  manner,  though  generally  motor,  are  by  no  means  necessarily  so. 


RELATIONS    OF   VESICULAR   AND    FIBROUS   NERVE-TISSUES. 
FJG.  122.  FIG.  123. 


431 


Microscopic  Ganglion  trom  Heart  of  Frog, 
showing  at  a,  a   Unipolar  Ganglionic  Cell. 


Bipolar  Ganglionic  Cells  and  nerve-fibres 
from  ganglion  of  5th  Pair  in  Lamprey. 


nervous  centres  of  Man  and  the  higher  Vertebrata;  whilst  the  latter  prevails  in 
Fishes.  But  in  certain  parts  of  the  nervous  centres  of  Man,  we  meet  with  gan- 
glionic  cells  sending-out  radiating  prolongations  to  the  number  of  three,  four, 
five,  six,  or  more ;  some  of  which  are  occasionally  to  be  traced  into  continuity 
with  the  axis-cylinders  of  nerve-tubes,  as  seen  at  a,  b}  Fig.  124 ;  whilst  others, 


FIG.  124. 


Stellate  Ganglionic  Cell,  from  '  substantia  ferruginea '  of  Human  Brain ;  one  of  its  pro- 
longations, a,  becoming  continuous  with  the  axis-cylinder  of  a  double-contoured  nerve- 
ftbre,  6. 

»t  i*  probable,  inosculate  with  those  of  other  stellate  cells.  Whether  more  than 
cue  fibre  ever  arises  from  one  of  these  vesicles,  cannot  yet  be  positively  stated. — 
We  should  be  by  no  means  justified  in  concluding,  however,  that  ganglionic  cell? 
have  no  other  structural  or  functional  relation  to  nerve-fibres,  than  that  whir-h 
they  derive  from  such  direct  continuity.  For  there  are  indubitably  many  gan 


4B2  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

glionic  cells,  which  are  simple  spheroids,  lying  among  the  nerve-tubes;  whilst 
on  the  other  hand,  there  are  numerous  instances  in  which  fibres  that  enter  the 
central  organs,  return  by  loops,  without  forming  any  closer  connection  with  gan- 
glion-cells, than  that  which  their  juxtaposition  brings-about.  It  cannot  be 
thought  probable,  either  that  the  simple  spheroidal  vesicles  are  destitute  of  phy- 
siological importance,  or  that  nerve-fibres  would  thus  pass-in  amongst  them,  and 
return,  if  some  purpose  were  not  answered  by  their  doing  so.  And  we  seem 
justified  therefore,  in  looking  at  this  as  one  of  the  regular  modes  in  which  the 
two  elementary  components  of  the  Nervous  System  are  brought  into  mutual 
action ;  the  whole  question,  however,  of  the  nature  of  that  action,  and  of  its 
diversities  in  the  several  cases  just  described,  being  one  which  is  at  present 
entirely  open. 

458.  The  general  relations  of  the  principal  Centres  of  the  Nervous  System  of 
Man,  having  been  already  considered  (§§  45 — 47),  it  is  only  requisite  here  to 
remark,  that  those  which  make  up  the  Cerebro-Spinal  portion  of  the  apparatus 
have  such  an  intimate  structural  relation  to  each  other,  and  so  much  more  fre- 
quently act  consentaneously  than  separately,  that,  notwithstanding  the  abundant 
evidence  of  the  diversity  of  their  respective  endowments,  there  is  considerable 
difficulty  in  the  determination  of  their  special  functions  ;  since  the  destruction 
or  removal  of  any  one  portion  of  the  Nervous  System,  not  only  puts  a  stop  to  the 
phenomena  to  which  that  portion  is  directly  subservient,  but  so  deranges  the 
general  train  of  nervous  activity,  that  it  often  becomes  impossible  to  ascertain,  by 
any  such  method,  what  is  its  real  share  in  the  entire  performance. — In  this 
difficulty,  however,  we  may  advantageously  have  recourse  to  the  study  of  the 
structure  and  actions  of  those  forms  of  the  Nervous  System  presented  to  us 
among  the  lower  animals,  in  which  its  ganglionic  centres  are  fewer  and  less 
intimately  connected,  and  in  which,  therefore,  it  is  more  easy  to  gain  an  acquaint- 
ance with  their  several  endowments.  And  from  an  extensive  survey  of  these, 
we  seem  able  to  deduce  the  following  conclusions,  which  afford  the  most  valuable 
guidance  in  the  study  of  the  Nervous  System  of  Man  :' — 

I.  The  Nervous  System,  in  its  lowest  and  simplest  form,  may  consist  of  but  a 
single  ganglionic   centre,2  with   afferent  and  motor  nerves,  whose  function   is 
essentially   internuncial ;    impressions  made  upon   the  afferent  fibres   exciting 
respondent  or  '  reflex'  movements  in  the  muscles  supplied  by  the  motor,  without 
any   necessary  intervention   of  consciousness.  —  Such   movements  are  properly 
distinguished  as  excito-motor. 

II.  A  simple  repetition  of  such  ganglionic  centres  may  exist  to  any  extent, 
without  heterogeneousness  of  function,  or  any  essential  departure  from  the  mode 
of  action  just  indicated;   each  of  these  centres  maybe  specially  connected  by 
afferent  and  motor  fibres  with  one  segment  or  division  of  the  body,  and  may 
minister  peculiarly  to  its  actions ;  but  the  several  centres  may  be  so  intimately 
connected  by  commissural  fibres,  that  an  impression  made  upon  the  afferent 
nerves  of  any  one  of  them  may  excite  respondent  motions  in  other  segments. — 
This  we  see  effected  through  the  annular  gangliated  cord  of  the  higher  Radiata, 
and  through  the  longitudinal  gangliated  cord  of  the  Articulate ;  the  disposition 
of  the  ganglia  and  of  their  connecting  cords,  having  reference  simply  to  the 
general  plan  of  the  body. 

in.  A  higher  form  of  Nervous  System  is  that  in  which  the  multiplication  of 
ganglionic  centres  has  reference,  not  to  the  multiplication  of  similar  parts  which 
are  to  be  alike  supplied  with  nervous  power,  but  to  the  exercise  of  a  diversity  of 

1  For  a  general  view  of  the  facts  on  which  these  conclusions  are  based,  see  "  Princ.  of 
Comp.  Phys.,"  Am.  Ed.,  Chap.  xin. 

1  It  may,  perhaps,  be  doubted  whether  any  Animal  really  exists,  possessing  such  a 
nervous  system,  and  yet  not  endowed  with  consciousness.  It  is  quite  certain,  however 
that  animals  do  exist  (the  Tunicated  Mollusca  for  example),  in  which  the  actions  above 
referred  to  are  the  only  ones  of  which  we  have  any  distinct  evidence  from  observation  of 
their  habits 


ITS   RELATION   TO    NERVOUS    SYSTEM    OF   INVERTEBRATA.  438 

functions,  through  the  instrumentality  of  different  structures  :  thus,  in  the  higher 
Articulated  and  Molluscous  tribes,  we  find  ganglionic  centres  specially  set  apart 
for  the  actions  of  deglutition  and  respiration,  as  well  as  for  those  of  locomotion  • 
but  their  modus  operandi  is  still  the  same,  these  actions  being  all  'excito-motor,' 
that  is,  being  performed  through  the  '  reflex'  agency  of  their  several  ganglionic 
centres,  without  the  necessary  intervention  of  consciousness.  These  centres  are 
connected  with  each  other  commissurally,  when  they  are  required  to  act  with 
consentaneousness ;  and  it  is  frequently  to  be  observed  in  the  most  developed 
forms  of  each  type,  that  they  come  into  actual  coalescence,  their  functional  dis- 
tinctness being  still  indicated,  however,  by  the  distribution  of  their  nerve-trunks. 

iv.  In  all  but  the  very  lowest  Invertebrata,  the  Nervous  System  includes,  in 
addition  to  the  foregoing,  certain  ganglionic  centres,  situated  in  the  neighbour- 
hood of  the  entrance  to  the  digestive  cavity,  and  connected  with  organs,  which, 
from  their  more  or  less  close  resemblance  to  our  own  instruments  of  special 
sense,  we  conclude  to  be  organs  of  sight,  smell,  hearing,  &c.  Now  as  we  know 
from  our  own  experience,  that  impressions  made  upon  these  organs  produce  no 
influence  on  our  actions  unless  we  become  conscious  of  them,  and  as  the  Inver- 
tebrata possess  no  distinct  ganglionic  centres  of  a  higher  character,  it  seems  to 
be  a  legitimate  inference,  that  these  'sensorial'  ganglia  are  the  instruments  by 
which  the  animals  furnished  with  them  are  rendered  cognizant  of  such  impres- 
sions, and  through  which  the  sensations  thus  called  into  existence  serve  to  prompt 
and  direct  their  movements.  What  is  commonly  designated  as  the  'brain'  of 
Invertebrata  (more  properly  their  'cephalic  ganglia')  cannot  be  shown  to  consist 
of  anything  else  than  an  assemblage  of  sensorial  centres;  and  its  actions  appear 
to  be  entirely  of  a  '  reflex'  character,  such  of  the  movements  of  these  animals  as 
are  not  excito-motor,  being  performed  (there  is  strong  reason  to  believe)  in  direct 
respondence  to  sensations  excited  by  internal  or  external  impressions.  Such 
movements,  therefore,  may  be  designated  as  sensori-motor,  or  con-sensual  Like 
the  preceding,  they  do  not  appear  to  involve  the  participation  either  of  Emotion, 
Reason,  or  Will;  and  the  proportion  which  they  bear  to  the  actions  of  the  excito- 
motor  kind,  seems  to  correspond  pretty  closely  with  the  relative  development  of 
the  cephalic  ganglia  and  of  the  rest  of  the  nervous  system,  as  is  very  obvious 
when  the  larva  and  imago  states  of  Insects  are  compared.  —  However  disjointed 
the  various  'excito-uiotor'  centres  may  be  amongst  each  other,  we  uniformly  find 
them  connected  with  the  '  sensory '  ganglia  by  commissural  tracts ;  and  this  ana- 
tomical fact,  with  many  phenomena  which  observation  and  experiment  upon  their 
actions  have  brought  to  light,  make  it  apparent,  that  besides  the  reflex  actions 
which  are  performed  through  their  own  direct  instrumentality,  the  sensory  gan- 
glia have  a  participation  in  those  performed  through  other  ganglionic  centres. 
Thus  it  seems  probable  that  a  stimulus  transmitted  downwards  from  the  sensory 
ganglia,  to  one  of  the  ganglia  of  the  trunk  of  a  Centipede,  excites  the  efferent 
nerves  of  that  ganglion  to  call  into  contraction  the  muscles  supplied  by  them, 
just  as  the  excitor  influence  arriving  at  that  ganglion  through  its  own  afferent 
nerves  would  do. 

459.  The  whole  Nervous  System  of  Invertebrated  animals,  then,  may  be  re- 
garded as  ministering  entirely  to  purely-reflex  action;  and  its  highest  develop- 
ment, as  in  the  class  of  Insects,  is  coincident  with  the  highest  manifestations  of 
the  'instinctive'  powers,  which,  when  carefully  examined,  are  found  to  consist 
entirely  in  movements  of  the  excito-motor  and  sensori-motor  kinds.  When  we 
attentively  consider  the  habits  of  these  animals,  we  find  that  their  actions,  though 
evidently  adapted  to  the  attainment  of  certain  ends,  are  very  far  from  evincing  a 
designed  adaptation  on  the  part  of  the  beings  that  perform  them,  such  as  that  of 
which  we  are  ourselves  conscious  in  our  own  voluntary  movements,  or  which  we 
trace  in  the  operations  of  the  more  intelligent  Vertebrata.  For,  in  the  first 
place,  these  actions  are  invariably  performed  in  the  same  manner  by  all  the  in- 
dividuals of  a  species,  when  the  conditions  are  the  same ;  and  thus  are  obviously 


134  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

to  be  attributed  rather  to  a  uniform  impulse,  than  to  a  free  choice ;  the  most  re- 
markable examples  of  this  being  furnished  by  the  economy  of  Bees,  Wasps,  and 
other  'social'  Insects,  in  which  every  individual  of  the  community  performs  its 
appropriate  part,  with  the  exactitude  and  method  of  a  perfect  machine.  The 
very  perfection  of  the  adaptation,  again,  is  often  of  itself  a  sufficient  evidence 
of  the  unreasoning  character  of  the  beings  which  perform  the  work ;  for,  if  we 
attribute  it  to  their  own  intelligence,  we  must  admit  that  this  intelligence  fre- 
quently equals,  if  it  does  not  surpass,  that  of  the  most  accomplished  Human 
reasoner.1  Moreover,  these  operations  are  performed  without  any  guidance  from 
experience ;  for  it  can  be  proved  in  many  cases,  that  it  is  impossible  for  the 
beings  which  execute  them  to  have  received  any  instruction  whatever ;  and  we 
see  that  they  do  not  themselves  make  any  progressive  attempt  towards  perfec- 
tion, but  that  they  accomplish  their  work  as  well  when  they  first  apply  them- 
selves to  it,  as  after  any  number  of  repetitions  of  the  same  acts.  It  is  interest- 
ing to  observe,  moreover,  that  as  these  instinctive  operations  vary  at  different 
periods  of  life,  so  there  is  a  corresponding  variation  in  the  structure  of  the  Ner- 
vous system.  Thus  we  see  that,  in  the  larva  of  the  Insect,  these  operations  are 
entirely  directed  towards  the  acquisition  of  food ;  and  its  organs  of  sense  and 
locomotive  powers  are  only  so  far  developed  as  to  serve  this  purpose.  But  in 
the  imago  or  perfect  Insect,  the  primary  object  is  the  continuance  of  the  race  j 
and  the  sensorial  and  motor  endowments  are  adapted  to  enable  the  individual  to 
seek  its  mate,  and  to  make  preparations  (frequently  of  a  most  elaborate  kind) 
for  the  nurture  of  the  offspring.  —  Hence  we  can  scarcely  fail  to  arrive  at  the 
conclusion,  that  the  adaptiveness  of  the  instinctive  operations  of  Insects,  &c., 
lies  in  the  original  construction  of  their  nervous  system,  which  causes  particular 
movements  to  be  executed  in  direct  respondence  to  certain  impressions  and  sen- 
sations. And  this  view  is  confirmed  by  the  comparison  of  such  movements  with 
those  which,  in  the  Human  subject,  are  most  directly  concerned  in  the  main- 
tenance of  the  life  of  the  individual,  and  in  the  perpetuation  of  the  race.  For 
we  have  the  evidence  of  our  own  consciousness  in  regard  to  these,  that,  however 
obvious  their  purpose  may  be,  and  however  complete  their  adaptation  to  that 
purpose,  they  are  performed,  not  with  any  notion  of  that  purpose,  but  at  the 
prompting  of  an  irresistible  impulse,  which  is  not  only  independent  of  all  in- 
telligent appreciation  of  the  result,  but  may  produce  its  effect  without  even 
affecting  the  consciousness  of  the  agent.  Thus  the  infant  seeks  the  nipple,  and 
puts  its  muscles  into  suctorial  action,  without  any  knowledge,  derived  from  ex- 
perience, that  by  so  doing  it  will  relieve  the  uneasy  feeling  of  hunger;  and  if 
we  could  imagine  a  man  coming  into  the  world  with  the  full  possession 'of  all 
his  faculties,  we  may  feel  tolerably  certain  that  he  would  not  wait  to  eat  until  he 
had  learned  by  experience  his  dependence  upon  food.  We  shall  see  (§  529)  that 
adult  animals  whose  Cerebral  hemispheres  have  been  removed,  will  eat  food  that 
is  put  into  their  mouths,  although  they  will  not  go  to  seek  it  ;  and  this  is  the 
case  with  many  Human  idiots.  When  the  functions  of  the  Brain  are  disturbed, 
or  in  partial  abeyance,  as  in  fever,  we  often  observe  a  remarkable  return  to  the 
instinctive  propensities  in  regard  to  food ;  and  the  Physician  frequently  derives 
important  guidance  with  respect  to  the  patient's  diet  and  regimen  (particularly 
as  to  the  administration  of  wine),  from  the  inclination  or  disinclination  which  he 
manifests.  So,  in  regard  to  the  intercourse  of  the  sexes,  the  impulse  which 
prompts  to  it  does  not  arise  from  a  knowledge  of  the  ultimate  purposes  which  it 
is  designed  to  answer;  and  the  higher  powers  of  the  mind  are  only  so  far  con- 
cerned in  it,  that  when  the  action  of  the  instinctive  impulse  has  led  to  the  for- 
mation of  a  definite  idea  of  the  object  of  desire,  the  Intelligence  is  prompted  to 
take  means  for  its  gratification.2 

1  See  "Princ.  of  Comp.  Phys.,"  Am.  Ed.,  p.  679. 

•  We  have  not,  perhaps,  any  right  to  affirm  that  there  is  nothing  ivhatevcr  analogous  in 
the  InvtTtebrata  to  the  Reasoning  powers  and  Will  of  higher  animals  ;  but  if  these  facul- 


GENERAL    VIEW    OF    MAN'S    PSYCHICAL    ENDOWMENTS.  435 

460.  Thus,    then,   the    type    of    psychical    perfection    among    Invertebrated 
animals,  which  is  manifested  in  the  highest  degree  in  the  Social  Insects,  consists 
in  the  exclusive  development  of  the  Instinctive  faculty ;  that  is,  of  automatic 
powers  of  a  very  simple  kind;    in  virtue  of  which,  each  individual  performs 
those  actions  to  which  it  is  directly  prompted  by  the  impulses  arising  out  of 
impressions  made  upon  its  afferent  nerves,  without  any  self-control  or  self-direc- 
tion ;  so  that  it  must  be  regarded  as  entirely  a  creature  of  necessity,  performing 
its  instrumental  part  in  the  economy  of  Nature  from  no  design  or  will  of  its 
own,  but  in  accordance  with  the  plan  originally  devised  by  its  Creator. 

461.  On  turning  to  the  Vertebrated  series,  on  the  other  hand,  we  find  that 
its  type  of  psychical  perfection — as  shown  in   Man — consists  in   the    highest 
development  of  the  Reason,  and  in  the  supreme  domination  of  the  Will,  to  which 
all    the  l  automatic '   actions,  save  those  which   are  absolutely  essential  to  the 
maintenance  of  the  Organic  functions,  are  brought  under  subjugation ;  so  that 
each  individual  becomes  not  only  a  thinking  and  reflecting,  but  a  self-moving 
and  self-co-ntrolling  agent,  whose  actions  are  performed  with  a  definite  purpose 
which  is  distinctly  before  his  own  view,  and   are    adapted  to  the   attainment 
of  their  end  by  his  own  intelligence.     This,  however,  is  only  true  of  Man  in 
his   most   elevated   state;    and   not   only  in  ascending   the  Vertebrated    scale, 
but  also  in  watching  the  progressive  evolution  of  his  mental  faculties  during  the 
earlier  periods  of  his  life,  may  we  trace  a  regular  gradation,  from  a  condition  but 
little  (if  at  all)  in  advance  of  that  of  the  higher  Invertebrata,  up  to  that  which 
is  displayed  in  the  noblest  examples  of  Humanity.     Through  the  entire  series, 
however,  we  perceive  that  the  Excito-motor  and   Sensori-motor  portion  of  the 
Nervous  system  (§  464)  constitutes  its  fundamental  and  essential  part;  serving 
not  merely  as  the  instrument  whereby  those  actions  are  performed,  which  are  as 
necessary  among  the  higher  animals  as  they  are  among  the  lower,  for  the  main- 
tenance of  the  Organic  functions  (§§  24,  25)  ;  but  also  as  the  immediate  recipient 
of  all  those  impressions  from  without,  by  which  the  higher  operations  of  Mind 
are  excited,  and  as  the  executant  of  the  actions  which  proceed  from  them.     But 
as  we  ascend  the  Vertebrated  scale,  or  as  we  watch  the  progressive  psychical 
development  of  the  Infant,  we  find  it  becoming  more  and  more  obvious  that  the 
actions  are  prompted,  not  so  much  by  simple  sensations,  as  by  ideas  or  notions  of 
the  objects  to  which  they  relate;  these  ideas  being  founded,  in  a  large  propor- 
tion of  instances,  upon  the  results  of  past  experience,  and  the  course  of  action 
being  shaped  in  accordance  with  it.     In  the  acts  of  animals  of  a  still  higher 
grade,  as  in  those  of  the  Child,  we  can  scarcely  fail  to  perceive  the  manifestation 
of  reasoning  processes  analogous  to  those  which  we  ourselves  perform,  and  the 
expressions  of  some  of  those  emotional  states  of  which  we  are  ourselves  conscious. 
The  superaddition  of  these  more  elevated  endowments,  in  the  Yertebrated  series, 
is  coincident  with  the  addition  of  a  peculiar  ganglionic  centre,  the   Cerebrums, 
to  the  Sensori-motor  apparatus;  and  the  relative  proportion  which  the  former 
bears  to  the  latter,  both  as  to  size  and  to  complexity  of  structure,  corresponds 
so  closely  with  the  degree  of  predominance  which  the  Intelligence  possesses  over 
the  Instinctive  propensities,  that  it  is  scarcely  possible  to  doubt  that  the  Cerebrum 
is  the  instrument  through  which  this  higher  form  of  psychical  power  is  exercised 
Much  of  this  exercise,  however,  may  still  be  automatic  in  its  nature;  for  so 
long  as  the  current  of  thought  and  feeling  flows-on  in  accordance  with  the  direct 
promptings  of  Suggestion,  and  without  any  interference  from  Yolition,  may  it  be 
considered  as  a  manifestation  of  the  « reflex '  activity  of  the  Cerebrum,  which 
ties  have  any  existence  among  them,  they  must  be  regarded  as  in  a  merely  rudimentary 
state,  corresponding  with  the  undeveloped  condition  of  the  Cerebrum.     The  only  distinct 
indication  of  intelligence  displayed  by  Invertebrata,  is  the  slight  degree  of  capacity  of 
"learning  by  experience"  which  some  of  them  display;  this  capacity  being  limited  to 
the  mere  formation  of  associations  between  the  physical  states  called-up  by  different  objects 
of  sense,  which  we  observe  to  be  the  first  stupe  in  the  development  of  the  mental  power* 
in  the  Human  infant.— (See  "PmNC.  OF  COMP.  PHYS.,"  Am.  Ed.£  682  note). 


}°)6  FUNCTIONS    OF   THE   CEREBRO-SPINAL    NERVOUS    SYSTEM. 

takes  the  form  of  a  mental  instinct.  This  reflex  activity  manifests  itself  not 
only  in  the  psychical  operations  themselves,  but  also  in  muscular  movements  ; 
and  these,  when  they  proceed  from  simple  ideas,  without  any  excitement  of 
feeling,  may  be  designated  as  ideo-motor  ;  whilst,  if  they  spring;  from  a  passion  or 
emotion,  they  are  termed  emotional.  The  mental  instincts,  however,  are  by  no 
means  as  invariable  in  the  different  individuals  of  the  same  species,  as  are  what 
may  be  termed  the  physical  Instincts  of  that  inferior  part  of  the  nervous 
apparatus,  which  is  more  closely  connected  with  the  maintenance  of  the  Organic 
life  ]  the  particular  changes  which  any  given  suggestions  will  excite  in  each, 
being  partly  determined  by  original  constitution,  and  partly  by  acquired  habits. 

462.  The  superiority  of  the  Mind  of  Man  over  that  of  the  most  elevated 
among  the  lower  animals,  consists,  not  only  in  the  far  greater  variety  and  range 
of  his  faculties,  but,  yet  more,  in  that  dominant  power  of  the  "Will,  which  en- 
ables him  to  utilize  them  with  the  highest  effect.     In  so  far  as  the  course  of  his 
thoughts  and  feelings  is  the  mere  result  of  the  action  of  external  impressions 
upon  an  organization  having  certain  respondent  tendencies,  must  he  be  con- 
sidered as  irresponsible  for  his  actions,  his  character  being  formed  for  instead 
of  by  him  :  but  in  so  far  as  he  can  exert  a  Volitional  power  of  directing  his 
thoughts  and  controlling  his  feelings,  may  he  rise  superior  to  circumstances, 
make  the  most  advantageous  use  of  the  Intellectual   faculties  with  which  he 
may  be  endowed,  and  bring  his  Moral  character  more  and  more  into  accord- 
ance with  the  highest  type  which  his  nature  may  be  capable  of  attaining  in 
its  present   sphere    of  existence.      Notwithstanding   the    evidences   of  ration- 
ality which  many  of  the  lower  animals  present,  and  the  manifestations  which 
they  display  of  emotions  that  are  similar  to  our  own,  there  is  no  ground  to 
believe  that  they  have  any  such  controlling  power  ;  on  the  contrary,  all  obser- 
vation seems  to  lead  to  the  conclusion,  that  they  are  under  the  complete  domina- 
tion of  the  ideas  and  emotions  by  which  they  may  be  for  the  time  possessed,  and 
have  no  power  either  of  repressing  these  by  a  forcible  act  of  Will,  or  of  turning 
the  attention,  by  a  like  voluntary  effort,  into  another  channel.     In  this  respect, 
then,  their  condition  resembles  that  of  the  Dreamer,  the  Somnambule,  or  the 
Insane  patient,  in  all  of  whom  this  voluntary  control  is  suspended,  and  who 
(when  their  minds  are  susceptible  of  external  impressions)  may  be  so  '  played 
upon '  by  the  suggestion  of  ideas,  that  any  respondent  action  consistent  with 
the  habitual  mental  state  of  the  individual,  may  be  evoked  by  an  appropriate 
stimulus ;  just  as  we  see  in  the  case  of  animals  that  are  trained  to  the  perform- 
ance of  particular  sets  of  movements,  which  are  executed  in  respondence  to  cer- 
tain promptings  conveyed  to  them  through  their  sensorium.     Now  between  the 
complete  want  of  this  controlling  power  of  the  Will,  and  the  most  perfect  pos- 
session of  it,  every  intermediate  gradation  is  presented  by  the  several  individuals 
which  make  up  the  Human  species;  some  persons  being  so  much  accustomed, 
in  consequence  of  the  weakness  of  their  Will,  to  act  directly  upon  the  prompting 
of  every  transient  impulse,  that  they  can  scarcely  be  said  to  be  voluntary  agents; 
and  others  allowing  certain  dominant  ideas  or  habitual  feelings  to  gain  such  a 
mastery  over  them,  as  to  exercise  that  determining  power  which  the  Will  alone 
ought  to  exert.     This  gradation  may  be  perfectly  traced  in  children,  in  whose 
education  the  development  of  the  faculty  of  '  self-control '  should  be  a  leading 
object ;  and  it  is  also  displayed  in  certain  phases  of  mental  Imbecility,  which 
result  from  a  deficiency  of  the  power  of  voluntarily  fixing  the  attention   upon 
any  object  of  consciousness,  and   of  thus  withdrawing  it  either  from  external 
objects  that  tend  to  distract  the  mino1,  or  from  notions  it  has  adopted  which  hold 
it  in  subjection. 

463.  When  we  apply  ourselves  to  the  study  of  the  Cerebro-Spinal  Nervous 
centres  of  Man,  we  find  ourselves  peculiarly  liable  to  be  misled  by  the  great 
development  which  the  Cerebrum  presents,  both  as  to  size  and  to  complexity  of 
structure,  in  proportion  to  the  other  centres ;  and  thus  it  has  happened  that, 


GENERAL    VIEW    OF    MAN'S   PSYCHICAL    ENDOWMENTS.  437 

through  the  too  exclusive  attention  commonly  paid  to  Human  Anatomy,  the 
meaning  of  the  facts  brought  to  light  by  dissection  has  been  very  commonly 
misapprehended,  and  many  of  the  physiological  interpretations  based  upon  them 
have  been  completely  negatived  by  more  extended  inquiry. — It  is  only,  in  fact, ' 
by  studying  the  Cerebro-Spinal  apparatus  in  its  lowest,  as  well  as  in  its  highest 
form,  and  by  bringing  the  intervening  grades  into  comparison  with  both  extremes, 
that  it  is  possible  to  establish  what  are  its  fundamental  or  essential,  and  what  its 
accessory  parts;  and  in  this  way  only  can  such  a  correspondence  be  established, 
between  the  development  of  a  particular  structure,  and  the  manifestation  of  a 
psychical  endowment,  as  may  enable  the  latter  to  be  attributed  with  any  degree 
of  probability  to  the  former.  In  fact  there  is  no  part  of  the  Human  Organism, 
as  to  which  the  advantages  of  such  a  comparison  are  so  striking-,  or  in  which  the 
value  of  the  "  experiments  ready  prepared  for  us  by  Nature  "  is  so  much  above 
that  of  the  results  of  artificial  mutilations. 

464.-  Cerebro- Spinal  Nervous  Centres. — Under  the  guidance,  then,  of  these 
principles,  we  find  that  we  may  distinguish,  as  the  fundamental  part  of  the 
Cerebro-Spiual  apparatus  of  Man,  the  Cranio-Spinal  Axis,  consisting  of  the 
Spinal  Cord,  the  Medulla  Oblongata,  and  the  Sensory  Ganglia,  and  altogether 
constituting  the  centre  of  automatic  movement. — The  Spinal  Cord,  consisting  of 
a  tract  of  vesicular  matter  enclosed  within  strands  of  longitudinal  fibres,  and 
giving-off  successive  pairs  of  intervertebral  nerves  which  are  connected  at  their 
roots  with  both  of  these  components,  is  obviously  homologous  with  the  gangliated 
ventral  column  of  the  Articulata,  chiefly  differing' from  it  in  the  continuity  of 
the  ganglionic  substance  which  occupies  its  interior;  and  each  segrnental  divi- 
sion of  it,  which  serves  as  a  centre  for  its  own  pair  of  nerves,  may  be  considered, 
like  each  ganglion  of  the  ventral  column  of  the  Articulata,  as  a  repetition  of  the 
single  'pedal'  or  locomotive  ganglion  of  the  Mollusca. — The  Medulla  Oblongata 
consists  of  a  set  of  strands,  which  essentially  correspond  with  the  cords  that  pass 
round  the  oesophagus  in  Invertebrated  animals,  connecting  the  cephalic  ganglia 
with  the  first  sub-cesophageal  ganglion ;  but  as  the  whole  cranio-spinal  axis  in 
the  Vertebrata  lies  above  the  alimentary  canal  (the  trunk  being  supposed  to  be 
in  a  horizontal  position),  there  is  no  such  divergence  of  these  strands,  the  only 
separation  between  them  being  that  which  is  known  as  the  ( fourth  ventricle/ 
Interposed  among  the  commissural  fibres  of  the  Medulla  Oblongata,  however,  are 
certain  collections  of  vesicular  matter,  which  serve  as  the  ganglionic  centres  for 
the  movements  of  respiration  and  deglutition,  and  which  thus  correspond  with 
the  respiratory  and  stoinato-gastric  ganglia  of  Invertebrated  animals.  This  incor- 
poration of  so  many  distinct  centres  into  one  system,  would  seem  destined  in  part 
to  afford  to  all  of  them  the  protection  of  the  vertebral  column ;  and  in  part  to 
secure  that  consentaneousness  of  action,  and  that  ready  means  of  mutual  influ- 
ence, which  are  peculiarly  requisite  in  beings  in  whom  the  activity  of  the  Ner- 
vous system  is  so  predominant.  Thus  the  close  connection  which  is  established 
in  the  higher  Vertebrated  animals,  between  the  respiratory  and  the  general 
locomotive  apparatus,  is  obviously  subservient  to  the  use  which  the  former  makes 
of  the  latter  in  the  performance  of  its  functions;  whilst,  on  the  other  hand,  the 
control  which  their  encephalic  centres  possess  over  the  actions  of  the  respiratory 
ganglia,  enables  the  will  to  regulate  the  inspiratory  and  expiratory  movements, 
in  the  manner  required  for  the  acts  of  vocalization. — Under  the  term  Sensory 
Ganglia,  may  be  comprehended  that  assemblage  of  ganglionic  masses  lying  along 
the  base  of  the  skull  in  Man,  and  partly  included  in  the  Medulla  Oblongata,  in 
which  the  nerves  of  the  ( special  senses/  Taste,  Hearing,  Sight,  and  Smell,  havo. 
their  central  terminations;  and  with  these  may  probably  be  associated,  the  two 
pairs  of  ganglionic  bodies  known  as  the  Corpora  Striata  and  Thalami  Optici,  into 
which  may  be  traced  the  greater  proportion  of  the  fibres  that  constitute  the 
various  strands  of  the  Medulla  Oblongata,  and  which  seem  to  stand  in  the  same 
kind  of  relation  to  the  nerves  of  Touch  or  'common  sensation/  that  the  Olfac- 
tive,  Optic,  Auditory,  and  Gustative  ganglia  bear  to  their  several  nerve-trunks 


438 


FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 


FIG.  125. 


465.  Now  it  is  not  a  little  interesting,  that  this  Cranio-Spinal  axis  which 
represents  in  Vertebrated  animals  the  whole  nervous  system  of  the  Invertebrata 
(with  the  exception  of  the  rudiments  of  the  Sympathetic  which  they  possess), 
should  exist  in  the  lowest  known  Vertebrated  animal  without  any  superaddition, 
and  should  be  sufficient  for  the  performance  of  all  its  actions.     Such  is  the  case 
in  the  curious  Amphioxus,  a  little  fish  which  presents  not  the  slightest  trace  of 
either  Cerebrum  or  Cerebellum,  and  in  which  even  the  sensory  ganglia  and  the 
organs  of  special  sense  have  only  a  rudimentary  existence ;  and,  in  which,  too, 
the  spinal  cord  is  composed  of  a  series  of  ganglia  that  are  obviously  distinct  from 
each  other,  although  in  close  approximation.    And  even  in  the  lower  Cyclostome 
Fishes,  the  condition  of  the  nervous  centres  is  very  little  above  this,  save  as 
regards  the  larger  development  of  the  sensory  ganglia. — This  condition  has  its 
parallel,  even  in  the  Human  species,  in  the  case  of  Infants,  which  are  occasion- 
ally born  without  either  Cerebrum  or  Cerebellum ;  such  have  existed  for  several 
hours,  or  even  days,  breathing,  sucking,  crying,  and  performing  various  other 
movements ;  and  there  is  no  physiological  reason,  why  their  lives  should  not  be 
prolonged,  if  they  be  nurtured  with  sufficient  care  (§  25). 

466.  In  Man,  however,  as  in  all  the  higher  Vertebrata,  we  find  superimposed 
(as  it  were)  upon  the  Sensory  ganglia,  and  constituting  the  principal  mass  of  the 

Encephalon,  the  bodies  which  are  known  as  the  Cerebral  Hemi- 
spheres, or  Hemispheric  Ganglia.  Now  when  these  are  so 
greatly  developed,  as  to  cover-in  and  obscure  the  Sensory  ganglia 
to  the  degree  which  presents  itself  in  Man,  it  is  not  surprising 
that  the  fundamental  importance  of  the  latter  should  not  be 
generally  recognized ;  in  Fishes,  however,  the  proportion  between 
two  sets  of  centres  is  entirely  reversed,  the  rudiments  of  the 
Cerebral  Hemispheres  (Fig.  125,  B)  being  usually  inferior  in  size 
to  the  Optic  ganglia  (c)  alone.  Indeed,  of  the  pair  of  ganglionic 
masses  to  which  that  designation  is  usually  applied,  it  may  be 
--B  almost  positively  stated,  that  the  greater  part  is  homologous  with 
the  Corpora  Striata  of  the  Human  brain ;  it  being  only  in  the 
•c  higher  Cartilaginous  Fishes,  that  a  ventricular  cavity  exists  in 
each  of  these  bodies,  separating  the  thin  layer  of  true  Cerebral 
substance  which  overlies  it,  from  the  ganglionic  mass  which  forms 
its  floor.  Between  these  two  extremes,  a  regular  gradation  is 
presented  in  the  intermediate  tribes. — Now  it  is  a  point  especially 
worthy  of  note,  that  no  sensory  nerves  terminate  directly  in  the 
Cerebrum,  nor  do  any  motor  nerves  issue  from  it;  and  there 
seems  a  strong  probability  that  there  is  not  (as  formerly  supposed) 
a  direct  continuity  between  even  all  or  any  of  the  nerve-fibres 
Brain  of  Cod.  distributed  to  the  body,  and  the  medullary  substance  of  the  Cere- 
[Brain  of  Pike,  brum.  For  whilst  the  nerves  of  'special'  sense  have  their  own 
according  ^to  Dr.  ganglionic  centres,  it  cannot  be  shown  that  the  nervous  fibres  of 
Jeftnes  Wyman.  <  general '  sense,  which  either  enter  the  cranium  as  part  of  the 
ED.].— A,  olfac-  &  ,  ,.  n  ,,  a  . 

tive  ganglia;  B,  cephahc  nerves,  or  which  pass-up  from  the  bpinal  Cord,  have  any 
cerebral  lobes;  ^higher  destination  than  the  Thalami  Optici  (§  519).  So  the 
optic  ganglia;  D,  motor-fibres  which  pass-forth  from  the  cranium,  either  into  the 
cerebellum.  cephalic  nerve-trunks,  or  into  the  motor  columns  of  the  Spinal 

cord,  though  commonly  designated  as  Cerebral,  cannot  be  cer- 
tainly said  to  have  a  higher  origin  than  the  Corpora  Striata.  And  we  shall  find 
strong  physiological  as  well  as  anatomical  ground  for  the  belief,  that  the  Cerebrum 
has  no  communication  with  the  external  world,  otherwise  than  by  its  connection 
with  the  Sensori-motor  apparatus ;  and  that  even  the  movements  which  are 
usually  designated  as  'voluntary'  are  only  so  as  regards  their  original  source, 
the  stimulus  which  calls  the  muscles  into  contraction  being  even  then  imme- 
diately issued  from  the  Cranio-Spinal  axis,  as  it  is  in  the  movements  prompted 
by  the  reflex  stimulation  of  an  external  impression. 


CEREBRO-SPINAL   NERVOUS    CENTRES   IN    GENERAL.  439 

467.  Wherever  a  Cerebrum  is  superimposed  upon  the  Sensory  Ganglia,  we 
find  another  ganglionic  mass,  the    Cerebellum,  superimposed  upon  the  Medulla 
Oblongata.     The  development  of  this  organ  bears  a  general,  but  by  no  means  a 
constant  relation  to  that  of  the  Cerebrum  ;  for  in  the  lowest  Fishes  it  is  a  thin 
lamina  of  nervous  matter  on   the   median  line,  only  partially  covering-in   the 
'  fourth  ventricle ;'  whilst  in  the  higher  Mammalia,  as  in  Man,  it  is  a  mass  of 
considerable  size,  having  two  lateral  lobes  or  hemispheres  in  addition  to  its  cen- 
tral portion.     The  direct  communication  which  the  Cerebellum  has  with  both 
columns  of  the  Spinal  cord,  and  the  comparatively  slight  commissural  connection 
which  it  possesses  with  the  higher  portions  of  the  Encephalic  centres,  justify  the 
supposition  that  it  is  rather  concerned  in  the  regulation  and  co-ordination  of  the 
actions  of  the  former,  than  in  any  proper  psychical  operations;  and  it  will  here- 
after be   shown   that  the  various   kinds   of  evidence   afforded    by  Comparative 
Anatomy,  by  Experimental  inquiry,  and  by  Pathological  observation,  all  tend  to 
support  this  view  of  its  function. 

468.  Now  although  every  segment  of  the  Spinal  Cord,  and  every  one  of  the 
Sensory  Ganglia,  may  be  considered,  in  common  with  the  Cerebrum,  as  a  true 
and  independent  centre  of  nervous  power,  yet  this  independence  is  only  mani- 
fested when  these  organs  are  separated  from  each  other;  either  structurally — by 
actual  division ;  or  functionally — by  the  suspension  of  the  activity  of  other  parts. 
In  their  state  of  perfect  integrity  and  complete  functional  activity,  they  are  all 
(at  least  in  Man)  in  such  subordination  to  the  Cerebrum,  that  they  only  minister 
to  its  actions,  except  in  so  far  as  they  are  subservient  to  the  maintenance  of  the 
Organic  functions,  as  in  the  automatic  acts  of  breathing  and  swallowing.     With 
regard  to  every  other  action,  the  Will,  if  it  possess  its  due  predominance,  can 
exercise  a  determining  power;  keeping  in  check  every  automatic  impulse,  and  re- 
pressing the  promptings  of  emotional  excitement.     And  this  seems  to  result  from 
the  peculiar  arrangement  of  the  nervous  apparatus;  which  causes  the  excitor  im- 
pression to  travel  in  the  upward  direction,  if  it  meet  with  no  interruption,  until 
it  reaches  the  Cerebrum,  without  exciting  any  reflex  movements  in  its  course. 
When  it  arrives  at  the  Sensorium,  it  makes  an  impression  on  the  consciousness 
of  the  individual,  and  thus  gives  rise  to  a  sensation;  and  the  change  thus  in- 
duced, being   further  propagated  from  the  sensory  ganglia    to    the  Cerebrum, 
becomes  the  occasion  of  the  formation  of  an  idea.     If  with  this  idea  any  plea- 
surable or  painful  feeling  should  be  associated,  it  assumes  the  character  of  an 
emotion;  and  either  as  a  simple  or  as  an  emotional  idea,  it  becomes  the  sub- 
ject of  intellectual  operations,  whose  final  issue  is  in  a  volitional  determination, 
or  act  of  the  Will,  which  may  be  exerted  in  producing  or  checking  a  muscular 
movement,  or  in  controlling  or  directing  the  current  of  thought. 

469.  But  if  this   ordinary  upward  course  be  anywhere  interrupted,  the  im- 
pression will  then  exert  its  power  in  a  transverse  direction,  and  a  '  reflex '  action 
will  be  the  result ;  the  nature  of  this  being  dependent  upon  the  part  of  the 
Cerebro-Spinal  axis,  at  which  its  ascent  had  been  checked.     Thus  if  the  inter- 
ruption be  produced  by  division  or  injury  of  the  Spinal  Cord,  so  that  its  lower 
part  is  cut-off  from  communication  with  the  encephalic  centres,  this  portion  then 
acts  as  an  independent  centre;  and  impressions  made  upon  it,  through  the  afferent 
nerves  proceeding  to  it  from   the  lower  extremities,  excite  violent  reflex  move- 
ments, which,  being  thus  produced  without  sensation,  are  designated  as  l  excito- 
inotor.'  —  So,  again,  if  the  impression  should  be  conveyed  to  the  Sensorium,  but 
should  be  prevented  by  the  removal  of  the  Cerebrum,  or  by  its  state  of  func- 
tional inaction,  or  by  the  direction  of  its  activity  into  some  other  channel,  from 
calling-forth  ideas  through  the  instrumentality  of  the  latter,  it  may  react  upon 
the  motor  apparatus  by  the  '  reflex '  power  of  the  Sensory  ganglia  themseives; 
as  seems  to  be  the  case  with  regard  to  those  locomotive  actions  which  are  main 
tained  and  guided  by  sensations  during  states  of  profound  abstraction,  when  thn 
attention  of  the  individual  is  so  completely  concentrated  upon  his  own  train  of 


440  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

thought,  that  he  does  not  perceive  external  objects,  although  his  movements  are 
obviously  guided  through  the  visual  and  tactile  senses.  Such  actions,  being 
dependent  upon  the  prompting  of  sensations,  are  *  sensori-motor '  or  *  consensual/ 
— But  further,  even  the  Cerebrum  responds  automatically  to  impressions  fitted  to 
excite  it  to  *  reflex '  action,  when  from  any  cause  the  Will  is  in  abeyance,  and  its 
power  cannot  be  exerted  either  over  the  muscular  system  or  over  the  direction 
of  the  thoughts.  Thus  in  the  states  of  Reverie,  Dreaming,  Somnambulism,  &c., 
whether  spontaneous  or  artificially  induced  (Sect  6,  7),  ideas  which  take  posses- 
sion of  the  mind,  and  from  which  it  cannot  free  itself,  may  excite  respondent 
movements ;  and  this  may  happen  also  when  the  force  of  the  Idea  is  morbidly 
exaggerated,  and  the  Will  is  not  suspended,  but  merely  weakened,  as  in  many 
forms  of  Insanity  (Sect.  8). 

470.  The  general  views  here  put-forth  in  regard  to  the  independent  and  con- 
nected actions  of  the  several  primary  divisions  of  the  Cerebro-Spinal  apparatus, 
may  perhaps  be  rendered  more  intelligible  by  the  following  Table,  which  is  in- 
tended to  represent  the  ordinary  course  of  operation  when  the  whole  is  in  a  state 
of  complete  functional  activity,  and  the  character  of  the  '  reflex '  actions  to  which 
each  part  is  subservient,  when  it  is  the  highest  centre  that  the  impression  can 
reach.  The  directing  power  of  the  Will  seems  to  be  most  strongly  exerted  over 
those  actions,  which  are  most  closely  connected  with  psychical  changes,  and  which 
are  exclusively  Cerebral  in  their  seat.  It  has  been  already  pointed-out,  that  the 
Cranio-spinal  axis  not  merely  serves  as  the  channel  for  the  reception  of  the  im- 
pressions which  excite  the  activity  of  the  Hemispheric  ganglia,  and  as  the  in- 
strument whereby  the  results  of  their  operation  are  brought  to  bear  upon  tho 
muscular  system;  but  that  it  is  also  the  centre  of  reflexion  through  which 
various  automatic  movements  are  called-forth,  that  are  immediately  concerned  in 
the  maintenance  of  the  organic  functions.  The  impressions  which  excite  these 
movements,  do  not  in  general  pass-on  to  the  Cerebrum;  for  we  only  perceive 
them,  when  we  specially  direct  our  attention  to  them,  or  when  they  exist  in  unusual 
potency.  Thus  we  are  unconscious  of  the  l  besoin  de  respirer '  by  which  our 
ordinary  movements  of  respiration  are  prompted ;  and  it  is  only  when  we  have 
refrained  from  breathing  for  a  few  seconds,  that  we  experience  a  sensation  of 
uneasiness  which  impels  us  to  make  forcible  efforts  for  its  relief.  Notwithstand- 
ing, however,  that  the  Cerebrum  is  thus  unconcerned  in  the  ordinary  perform- 
ance of  these  automatic  movements,  yet  it  can  exert  a  certain  degree  of  control 
over  many  of  them,  so  as  even  to  suspend  them  for  a  time ;  but  in  no  instance 
can  it  carry  this  suspension  to  such  an  extent,  as  seriously  to  disarrange  the 
Organic  functions;  thus,  when  we  have  voluntarily  refrained  from  breathing  for 
a  few  seconds,  the  inspiratory  impulse  so  rapidly  increases  in  strength  with  the 
continuance  of  the  suspension,  that  it  at  last  overcomes  the  most  powerful  effort 
we  can  make  for  the  repression  of  the  movements  to  which  it  prompts  (§  302, 
note}.  Now  in  this  and  similar  cases,  it  would  seem  as  if  the  Will  interfered  to 
prevent  that  direct  transverse  passage  of  the  stimulus  from  the  afferent  to  the 
efferent  nerves,  through  the  Cranio-Spinal  axis,  which  constitutes  the  ordinary 
line  of  action  for  impressions  having  their  origin  in  the  necessities  of  the 
Organic  or  Vegetative  life  of  the  individual.  That  the  Will  should  have  a  cer- 
tain degree  of  control  over  these  movements,  is  necessary  in  order  that  they  may 
be  rendered  subservient  to  various  actions  which  are  necessary  for  the  due  exer- 
cise of  Man's  psychical  powers ;  but  that  they  should  not  be  left  dependent  upon 
its  exercise,  and  should  even  be  executed  in  opposition  to  it,  when  the  wants  of 
the  system  imperatively  demand  their  performance,  constitutes  a  wise  provision 
for  securing  Life  against  the  chance  of  inattention  or  momentary  caprice. 


CEREBRO-SPINAL   NERVE-TRUNKS    IN   GENERAL.  441 

WILL , 


Intellectual  Operation 


J 


§ 
Emotions  }-3©-^  CEREBRUM 

centre  of  emotional  and  ideo-motor  reflexion 


V ; 

Ideas 


Sensations S£-»SENSORY    GANGLIA 


centre  of  sensori-motor  reflexion 


Impressions SS-^SPINAL  CORD- 


centre  of  excito-motor  reflexion 


Motor  Impulse. 


471.  The  Cerebro-Spinal  system  is  intimately  blended  with  another  set  of 
ganglionic  centres  and  nerve-trunks,  scattered  in  different  parts  of  the  body,  but 
mutually  connected  with  each  other;  this  is  commonly  termed  the  Sympathetic 
system ;  but  not  unfrequently,  from  the  position  of  its  principal  centres,  and 
their  evident  functional  relation  to  the  apparatus  of  Organic  life,  the  Visceral 
system.  To  this  system  we  are  probably  to  refer,  not  only  the  Semilunar  and 
Cardiac  ganglia  (which  seem  to  be  its  principal  centres),  with  the  chain  of  cra- 
nial, cervical,  thoracic,  lumbar,  and  sacral  ganglia,  which  are  in  nearer  connection 
with  the  Cerebro-spinal  system ;  but  also  numerous  minute  ganglia,  which  are  to 
be  found  on  its  branches  in  various  parts.  Moreover,  the  ganglia  upon  the 
posterior  roots  of  the  Spinal  nerves,  and  those  upon  the  roots  and  trunks  of  cer- 
tain Cranial  nerves,  may  be  ranked  with  considerable  probability  under  the  same 
category;  and  if  such  be  the  case,  those  fibres  contained  in  the  cerebro-spinal 
nerves,  which  have  these  as  their  ganglionic  centres,  must  also  be  accounted  as 
belonging  to  the  Sympathetic  system.  On  the  other  hand,  there  unquestionably 
exist  numerous  fibres  in  the  Visceral  system,  which  proceed  into  it  from  the 
Cerebro-spinal  system ;  these,  however,  are  not  uniformly  distributed,  for  some 
of  the  Visceral  nerves  contain  few  or  none  of  them,  whilst  in  others  they  are 
numerous.  The  branches  by  which  the  Sympathetic  system  communicates  with 
the  Cerebro-spinal,  ^pd  which  were  formerly  considered  as  the  roots  of  the  Sym- 
pathetic system,  seem  to  contain  fibres  of  both  kinds; — i.e.,  Cerebro-spinal  fibres 
passing  into  the  Sympathetic,  and  Sympathetic  fibres  passing  into  the  Cerebro- 
spinal.  The  latter  are  chiefly,  if  not  entirely,  transmitted  into  the  anterior 
branches  of  the  Spinal  nerves;  tlae  posterior  branches  being  apparently  supplied 
with  sympathetic  fibres  from  the  ganglia  on  their  own  posterior  roots.  Some  of 
these  last  fibres  also  pass  from  the  Cerebro-spinal  into  the  Sympathetic  system. 
By  these  communications,  the  two  systems  of  fibres  are  so  blended  with  each 
other,  that  it  is  impossible  to  isolate  them.  —  The  branches  proceeding  from  the 
Semilunar  ganglia  are  distributed  upon  the  abdominal  viscera;  and  those  of  the 
Cardiac  ganglia  upon  the  heart  and  the  vessels  proceeding  from  it.  The  latter 
seem  to  accompany  the  arterial  trunks  through  their  whole  course,  ramifying 
minutely  upon  their  surface;  and  it  can  scarcely  be  doubted  that  they  exercise 
an  important  influence  over  their  functions.  What  the  nature  of  that  in- 
fluence may  be,  however,  will  be  a  subject  for  further  inquiry  (CHAP.  XV.).  It 
is  so  evidently  connected  with  the  operations  of  nutrition,  secretion,  &c.,  that 
the  designation  'nervous  system  of  organic  life,'  as  applied  to  this  system,  does 
not  seem  objectionable,  provided  that  we  do  not  understand  it  as  denoting  the 
dependence  of  these  functions  upon  it.  —  The  inter-penetration  of  the  Cerebro 


442  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS    SYSTEM. 

Bpinal  system  by  the  Sympathetic,  is  strongly  marked  by  these  two  circumstan- 
ces; —  that,  in  some  of  the  lower  Vertebrata,  the  distribution  of  their  trunks 
cannot  be  separately  distinguished;  —  and  that,  even  in  the  highest,  some  of  the 
glands,  of  which  the  secretion  is  most  directly  influenced  by  the  condition  of  the 
mind,  are  supplied  with  most  of  their  nerves  from  the  cerebro-spinal  system,  the 
•lachrymal  and  sublingual  glands  receiving  large  branches  from  the  fifth  pair,  and 
the  mammary  glands  from  the  intercostal  nerves. 

472.  Cerebro- Spinal  Nerve-Trunks. — Having  thus  considered  the  principal 
attributes  of  the  ganglionic  centres  of  the  Cerebro-Spinal  system,  we  have  next 
to  inquire  into  those  of  the  nerve-trunks  which  are  connected  with  them.     It  is 
only  in  the  Vertebrata,  that  the  difference  between  the  afferent  and  efferent  fibres 
of  the  nerves  has  been  satisfactorily  determined.     The  merit  of  this  discovery  is 
almost  entirely  due  to  Sir  C.  Bell,  who  has  led  to  it  by  a  chain  of  reasoning  of 
a  highly  philosophical  character;    and  although  his  first  experiments  on  the 
Spinal  nerves  were  not  satisfactory,  he  virtually  determined  the  respective  func- 
tion of  their  two  roots, — the  posterior  as  sensory  (afferent),  the  anterior  as  motor 
(efferent), — by  experiments  and  pathological  observations  upon  the  Cranial  nerves, 
some  of  which  contain  only  one  class  of  fibres  to  the  exclusion  of  the  other, 
before  any  other  physiologist  came  into  the  field.1     Subsequently  his   general 
views  were  confirmed  by  the  very  decided  experiments  of  Miiller;    but  until 
very  recently,  some  obscurity  hung  over  a  portion  of  the  phenomena.     It  was 
from  the  first  maintained  by  Magendie,  and  has  been  subsequently  asserted  by 
other  physiologists,  that  the  posterior  and  anterior  roots  of  the  nerves  were  loth 
concerned  in  the  reception  of  impressions  and  in  the  production  of  motions ;  for 
that,  on  touching  the   posterior  roots,  not  only  the  sensibility  of  the  animal 
seemed  to  be  affected,  but  muscular  motions  were  excited :  and  that,  when  the 
anterior  roots  were  touched,  the  animal  gave  signs  of  pain,  at  the  same  time  that 
convulsive  movements  were  performed.     These  physiologists  were  not  willing, 
therefore,  to  admit  more,  than  that  the  posterior  roots  were  especially  sensory,  and 
the  anterior  especially  motor.     But  the  knowledge  we  now  possess  of  the  l  reflex ' 
function  of  the  Spinal  Cord,  enables  the  former  portion  of  these  phenomena  to 
be  easily  explained.     The  motions  excited  by  irritating  the  posterior  roots,  are 
found  to  be  entirely  dependent  upon  their  connection  with  the  Spinal  Cord,  and 
upon  the  integrity  of  the  anterior  roots  and  of  the  trunks  into  which  they  enter, 
whilst  they  are  not  checked  by  the  separation  of  the  posterior  roots  from  the 
peripheral  portion  of  the  trunk :  it  is  evident,  therefore,  that  excitation  of  the 
posterior  roots  does  not  act  immediately  upon  the  muscles,  through  the  trunk  of 
the  nerve  which  they  contribute  to  form  ;  but  that  it  excite^  a  reflex  motor  im- 
pulse in  the  Spinal  Cord,  which  is  propagated  through  the  anterior  roots  to  the 
periphery  of  the  system.     The  converse  phenomenon,  the  apparent  sensibility  of 
the  anterior  roots,  has  been  explained  by  the  experiments  of  Dr.  Krouenberg,2 
which  seemed  to  prove  that  it  is  dependent  upon  a  branch  from  the  posterior 
roots,  passing  into  the  anterior  roots  at  their  point  of  inosculation,  and  then 
directing  itself  towards  the  cord  (§  477). 

473.  Every  fibre,  there  is  reason  to  believe,  runs  a  distinct  course,  between  the 
central  organ,  in  which  it  loses  itself  at  one  extremity,  and  the  organ  of  sense, 
muscle,  or  other  tissue,  in  which  it  terminates  at  the  other ;  in  the  terminal  rami- 
fications of  the  nerves,  however,  a  subdivision  of  the  fibres  is  frequently  observ- 
ble.     Each  nervous  trunk  is  made-up  of  several  fasciculi  of  these  fibres;  and 
each  fasciculus  is  composed  of  a  large  number  of  the  ultimate  fibres  themselves. 
Although  the  fasciculi  occasionally  intermix  and  exchange  fibres  with  one  another 
(as  occurs  in  a  plexus),  the  fibres  themselves  never  inosculate.     Each  fibre  would 
Beem,  therefore,  to  have  its  appropriate  office,  which  it  cannot  share  with  another. 
Several  objects  appear  to  be  attained  by  the  plexiform  arrangement.     In  some 

*  See  "  Brit,  ami  Foreign  Med.  Review,"  vol.  ix.  p.  140,  &c. 

•  "  Muller's  Archiv.,"  1839,  Heft  v.  ;  and  "  Brit,  and  For.  Med.  Rev.,"  vol.  ix.  p.  547. 


CEREBRO-SPINAL    NERVE-TRUNKS    IN    GENERAL  448 

instances  it  serves  to  intermix  fibres,  which  have  endowments  fundamentally 
different  :  for  example,  the  Spinal  Accessory  nerve,  at  its  origin,  appears  to  be 
exclusively  motor,  and  the  roots  of  the  Pneumogastric  to  be  exclusively  afferent; 
but  by  the  early  admixture  of  these,  a  large  number  of  motor  fibres  are  imparted 
to  the  Pneumogastric,  and  are  distributed  in  variable  proportion,  with  its  different 
branches;  whilst  a  few  of  its  sensory  filaments  seem  to  enter  the  Spinal  Acces 
sory. — In  other  instances,  the  object  of  a  plexus  appears  to  be,  to  give  a  more 
advantageous  distribution  to  fibres,  which  all  possess  corresponding  endowments, 
Thus  the  Brachial  plexus  mixes-together  the  fibres  arising  from  five  segments  of 
the  spinal  cord,  and  sends  off  five  principal  trunks  to  supply  the  arm.  Now  if 
each  of  these  trunks  had  arisen  by  itself,  from  a  distinct  segment  of  the  spinal 
cord,  so  that  the  parts  on  which  it  is  distributed  had  only  a  single  connection 
with  the  nervous  centres,  they  would  have  been  much  more  liable  to  paralysis 
than  at  present. — By  means  of  the  plexus,  every  part  is  supplied  with  fibres 
arising  from  each  segment  of  the  spinal  cord;  and  the  functions  of  the  whole 
must  therefore  be  suspended,  before  complete  paralysis  of  any  part  can  occur 
from  a  cause  which  operates  above  the  plexus.  Such  a  view  is  borne-out  by 
direct  experiment;  for  it  has  been  ascertained  by  Panizza  that,  in  Frogs,  whose 
Crural  plexus  is  much  less  complicated  than  that  of  Mammalia,  section  of  the 
roots  of  one  of  the  three  nerves  which  enter  into  it,  produces  little  effect  on  the 
general  movements  of  the  limb ;  and  that,  even  when  two  are  divided,  there  is 
no  paralysis  of  any  of  its  actions,  all  being  weakened  in  a  nearly  similar  degree. 
But  as  Dr.  Gull  has  pointed  out,1  one  use  of  such  a  plexus  as  the  brachial  or  the 
crural  appears  to  be,  to  bring  the  muscles  which  derive  their  nervous  supply 
from  it,  into  relation  with  different  ganglionic  segments  of  the  Spinal  Cord;  each 
of  which  may  exert  a  diverse  action,  either  in  virtue  of  its  own  endowments,  or 
of  the  influence  of  the  will  upon  it ;  so  that  groups  of  muscles  may  thus  be 
associated  for  combined  actions.  All  consideration  of  the  mode  in  which  we 
make  use  of  our  muscles,  and  of  the  power  which  we  have  over  them,  leads  to 
the  conclusion  that  each  ganglionic  centre  has  a  specific  and  limited  sphere  of 
influence,  producing  certain  movements  and  no  others ;  hence  for  the  execution 
of  a  variety  of  movements  in  harmonious  combination  with  each  other,  it  seems 
requisite  that  the  nervous  supply  of  each  muscle  should  be  derived  from  several 
different  centres ;  and  thus  it  is,  that  the  complication  of  plexuses  comes  to  be 
related  to  the  variety  of  movements  of  the  parts  supplied  through  them. — It  is 
not  a  little  interesting  to  remark,  that  arrangements  of  a  similar  kind  should 
present  themselves  among  the  higher  Invertebrata  (PRINC.  OF  COMP.  PHYS. 
Am.  Ed.,  §§646,  657). 

474.  The  following  statements,  in  which  the  doctrines  of  Prof.  Miiller2  are 
adopted  with  some  modifications  and  additions,  embody  the  general  principles 
ascertained  by  experiment,  respecting  the  transmission  of  Sensory  and  Motor 
impressions  along  the  nerves  which  respectively  minister  to  them.  Their 
rationale  will  be  at  once  understood,  from  the  facts  already  mentioned  in  regard 
to  the  isolated  character  of  each  fibril,  and  the  identity  of  its  endowments 
through  its  whole  course. 

I.  When  the  whole  trunk  of  a  sensory  nerve  is  irritated,  a  sensation  .is  pro- 
duced, which  is  referred  by  the  mind  to  the  parts  to  which  its  branches  are 
ultimately  distributed  ;  and  if  only  part  of  the  trunk  be  irritated,  the  sensation 
will  be  referred  to  those  parts  only,  which  are  supplied  by  the  fibrils  it  contains. — 
This  is  evidently  caused  by  the  production  of  a  change  in  the  sensorium,  cor- 
responding with  that  which  would  have  been  transmitted  from  the  peripheral 
organs  of  the  nerves,  had  the  impression  been  made  upon  them  (§  599).  Such 
a  change  only  requires  the  integrity  of  the  afferent  trunk  between  the  point 
irritated  and  the  sensorium,  and  is  not  at  all  dependent  upon  the  state  of  the 

1  «  Gulstonian  Lectures  on  the  Nervous  System,'  in  "Medical  Times,"  1849,  p.  372. 

2  "Elements  of  Physiology,"  translated  by  Dr.  Baly;  pp.  680,  686. 


444  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

peripheral  part  to  which  the  sensations  are  referred ;  for  this  may  have  been 
paralysed  by  the  division  or  other  lesion  of  the  nerve,  or  may  have  been  alto- 
gether separated  as  in  amputation,  or  the  relative  position  of  its  parts  may  have 
been  changed,  as  in  autoplastic  operations.  So,  when  different  parts  of  the 
thickness  of  the  same  trunk  are  separately  and  successively  irritated,  the  sensa- 
tions are  successively  referred  to  the  several  parts  supplied  by  these  divisions. 
This  may  be  easily  shown  by  compressing  the  ulnar  nerve  in  different  directions, 
where  it  passes  at  the  inner  side  of  the  elbow-joint. — Still  the  mind  undoubtedly 
does  possess  a  certain  power  of  discriminating  the  part  of  the  nerve-trunk  on 
which  the  impression  is  made;  for  whilst  this  impression  is  such  as  to  produce 
sensations  that  are  referred  to  its  peripheral  extremities,  pain  is  at  the  same  time 
felt  in  the  spot  itself;  and  it  would  seem  as  if  slight  impressions  are  only  felt  in 
the  latter  situation,  at  least  in  the  normal  condition  of  the  trunk  or  fibre.  Thus, 
as  it  has  been  well  remarked  by  Volkmann,  "if  a  needle's  point  be  drawn  in  a 
straight  line  across  the  back,  or  the  thigh,  or  any  part  in  which  the  nerves  are 
widely  placed,  the  mind  perceives  the  line  of  irritation  as  a  straight  one  ]  whereas, 
if  it  referred  all  impressions  to  the  ends  of  irritated  fibres,  this  mode  of  irrita- 
tion should  be  felt  in  sensations  variously  scattered  about  the  line,  at  the  points 
where  the  nerve-fibres  crossed  by  the  needle  terminate."1 

II.  The  sensation  produced  by  irritation  of  a  branch  of  the  nerve,  is  confined 
to  the  parts  to  which  that  branch  is  distributed,  and  does  not  affect  the  branches 
which  come-off  from  the  nerve  higher  up. — The  rationale  of  this  law  is  at  once 
intelligible :  but  it  should  be  mentioned  that  there  are  certain  conditions,  in 
which  the  irritation  of  a  single  nerve  will  give  rise  to  sensations  over  a  great 
extent  of  the  body.  This  '  radiation  of  sensations'  seems  rather  due,  however, 
to  a  particular  state  of  the  central  organs,  than  to  any  direct  communication 
among  the  peripheral  fibres. 

in.  The  motor  influence  is  propagated  only  in  a  centrifugal  direction,  never 
in  a  retrograde  course.  It  may  originate  in  a  spontaneous  change  in  the  central 
organs,  or  it  may  be  excited  by  an  impression  conveyed  to  them  through  afferent 
nerves ;  but  in  both  cases  its  law  is  the  same. 

IV.  When  the  whole  trunk  of  a  motor  nerve  is  irritated,  all  the  muscles  which 
it  supplies  are  caused  to  contract.  This  contraction  evidently  results  from  the 
similarity  between  the  effect  of  an  artificial  stimulus  applied  to  the  trunk  in  its 
course,  and  that  of  the  change  in  the  central  organs  by  which  the  motor  influ- 
ence is  ordinarily  propagated.  But  when  only  a  part  of  the  trunk  or  a  branch 
is  irritated,  the  contraction  is  usually  confined  to  the  muscles  which  receive  their 
nervous  fibres  from  it  j  in  this  instance,  as  in  the  other,  there  is  no  lateral  com- 
munication between  the  fibrils. — An  exception  exists,  however,  in  regard  to  gal- 
vanic irritation,  which  may  be  transmitted  laterally  when  its  ordinary  course  is 
checked;  as  has  been  shown  by  the  following  ingenious  experiment  of  M.  du 
Bois-Reymond.  If  any  motor  nerve  be  selected  which  divaricates  into  two 
branches  (as,  for  example,  the  sciatic  nerve  of  a  frog,  which  divides  above  the 
bend  of  the  knee  into  the  tibial  and  peroneal  branches),  and  a  galvanic  stimulus 
be  applied  to  either  of  these  branches,  this  having  been  first  divided  above  its 
insertion  into  the  muscles,  the  electrotonic  state  will  be  developed,  not  merely  in 
the  portion  of  the  trunk  continuous  with  that  branch,  but  also  in  that  which  is 
continuous  with  the  other  branch,  as  will  be  made  apparent  by  the  contraction  in 
the  muscles  supplied  by  the  latter.  That  this  experiment  may  be  free  from  the 
possible  fallacy  resulting  from  the  excitement  of  reflex  action,  the  trunk  of  the 
sciatic  nerve  should  be  divided  high-up,  or  the  spinal  cord  be  destroyed. 

475.  Determination  of  the  Functions  of  Nerves. — Various  methods  of  deter- 

1  "  Kirkes  and  Paget's  Handbook  of  Physiology,"  p.  296,  Am.  Ed. — It  does  not  seem  im- 
probable, however,  that  in  the  case  of  the  compression  or  other  irritation  of  a  large  nerve- 
trunk,  the  local  pain  may  be  produced  through  the  instrumentality  of  nervi  nervorum,  the 
existence  of  which  is  scarcely  less  probable  than  that  of  vasa  vasorum. 


DETERMINATION    OF    THE  FUNCTIONS   OF    NERVES.  445 

mining  the  functions  of  particular  nerves  present  themselves  to  the  Physiological 
inquirer.      One  source  of  evidence  is  drawn  from  their  peripheral  distribution. 
For  example,  if  a  nervous  trunk  is  found  to  lose  itself  entirely  in  the  substance 
of  Muscles,  it  may  be  inferred  to  be  chiefly,  if  not  entirely,  motor  or  efferent. 
In  this  manner,  Willis  long  ago  determined  that  the  Third,  Fourth,  Sixth,  Portio 
dura  of  the  Seventh,  and  Ninth  cranial  nerves,  are  almost  entirely  subservient  to 
muscular  movement ;  and  the  same  had  been  observed  of  the  fibres  proceeding 
from  tho  small  root  of  the  Fifth  pair,  before  Sir  C.  Bell  experimentally  deter- 
mined the  double  function  of  that  division  of  the  nerve  into  which  alone  it  enters. 
Again,  where  a  nerve  passes  through  the  muscles,  with  little  or  no  ramification 
among  them,  and  proceeds  to  a   Cutaneous  or  Mucous  surface,  on  which  its 
branches  are  minutely  distributed,  there  is'"equal  reason  to  believe  that  it  is  of  a 
sensory  or  rather  of  an  afferent  character.     In  this  manner  Willis  came  to  the 
conclusion,  that  the  Fifth  pair  of  cranial  nerves  differ  from  those  previously  men- 
tioned, in  being  partly  sensory.     Further,  where  a  nerve  is  entirely  distributed 
upon  a  surface  adapted  to  receive  impressions  of  a  special  kind,  as  the  Schneide- 
rian  membrane,  the  retina,  or  the  membrane  lining  the  internal  ear,  it  may  be 
inferred  that  it  is  not  capable  of  transmitting  any  other  kind  of  impressions ;  for 
experiment  has  shown  that  the  special  sensory  nerves  do  not  possess  common 
sensibility.     The  case  is  different,  however,  in  regard  to  the  sense  of  taste,  which 
originates  in  impressions  not  far  removed  from  those  of  ordinary  touch ;  and  it  is 
probable  that  the  same  nerves  minister  to  both. — Anatomical  evidence  of  this 
kind  is  valuable  also,  not  only  in  reference  to  the  functions  of  a  principal  trunk, 
but  even  as  to  those  of  its  several  branches,  which,  in  some  instances,  differ  con- 
siderably.    Thus,  some  of  the  branches  of  the  Pneumogastric  are  especially  motor, 
and  others  almost  exclusively  afferent;  and  anatomical  examination,  carefully 
prosecuted,  not  only  assigns  the  reasons  for  these  functions,  when  ascertained, 
but  is  in  itself  nearly  sufficient  to  determine  them.     For  the  superior  laryngeal 
branch  is  distributed  almost  entirely  upon  the  mucous  surface  of  the  larynx,  the 
only  muscle  it  supplies  being  the  crico-thyroid ;  whilst  the  inferior  laryngeal  or 
recurrent  is  almost  exclusively  distributed  to  the  muscles.     From  this  we  might 
infer,  that  the  former  is  an  afferent,  and  the  latter  a  motor  nerve ;  and  experi- 
mental enquiries  (as  we  have  seen,  §  304)  fully  confirm   this  view.     In  like 
manner  it  may  be  shown,  that  the  Glosso-pharyngeal  is  chiefly  an  afferent  nerve, 
since  it  is  distributed  to  the  surface  of  the  tongue  and  pharynx,  and  scarcely  at  all 
to  the  muscles  of  those  parts,  whilst  the  pharyngeal  branches  of  the  Pneumogas- 
tric are  chiefly,  if  not  entirely,  motor  (§  81).     Lower  down,  however,  the  branches 
of  the  Glosso-pharyngeal  cease,  and  the  cesophageal  branches  of  the  Pneumogas- 
tric are  distributed  both  to  the  mucous  surface  and  to  the  muscles,  from  which  it 
may  be  inferred  that  they  are  both  afferent  and  motor;  a  deduction  which  expe- 
riment confirms  (§  82). — We  perceive,  therefore,  that  much  knowledge  of  the 
function  of  a  nerve  may  be  obtained,  from  the  attentive  study  of  its  ultimate  dis- 
tribution ;  but  it  is  necessary  that  this  should  be  very  carefully  ascertained, 
before  it  is  made  to  serve  as  the  foundation  for  physiological  inferences.     As  an 
example  of  former  errors  in  this  respect,  may  be  mentioned  the  description  of  the 
Portio  dura  of  the  Seventh,  as  first  given  by  Sir  C.  Bell ;  for  he  incorrectly 
stated  it  to  be  distributed  to  the  skin  as  well  as  to  the  muscles  of  the  face,  and 
erroneously  regarded  it  as  in  part  an  afferent  nerve,  subservient  to  respiratory 
impressions  as  well  as  to  motions.     In  the  same  manner,  from  inaccurate  obser- 
vation of  the  ultimate  distribution  of  the  Superior  Laryngeal  nerve,  it  was  long 
regarded  as  that  which  stimulated  to  action  the  constrictors  of  the  glottis. 

476.  But  the  knowledge  obtained  by  such  anatomical  examinations  alone -is  of 
a  very  general  kind ;  and  requires  to  be  made  particular, — to  be  corrected  and 
modified, — by  other  sources  of  information.  One  of  these  relates  to  the  con- 
nexion of  the  trunks  with  the  central  organs.  The  evidence  derived  from  thi? 
source,  however,  is  seldom  of  a  very  definite  character ;  and,  in  fact,  Physiolo 


146  FUNCTIONS    OF  THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

gists  have  rather  been  accustomed  to  judge  of  the  functions  of  particular  divisions 
of  the  nervous  centres  by  those  of  the  nerves  with  which  they  are  connected, 
than  to  draw  aid  from  the  former  in  the  determination  of  the  latter.  Still,  this 
kind  of  examination  is  not  without  its  use,  when  there  is  reason  to  believe  that 
a  particular  tract  of  fibrous  structure  has  a  certain  function,  and  when  the  office 
of  a  nerve  whose  roots  terminate  in  it  is  doubtful.  Here,  again,  however,  very 
minute  and  accurate  examination  is  necessary,  before  any  sound  physiological 
inferences  can  be  drawn  from  facts  of  this  description ;  and  many  instances 
might  be  adduced  to  show,  that  the  real  connexions  of  nerves  and  nervous  cen- 
tres are  often  very  different  from  their  apparent  ones. 

477.  Most  important  information,  as  to  the  functions  of  particular  nerves  may 
be  drawn  from  experimental  inquiries  ;  but  these  also  are  liable  to  give  fallacious 
results,  unless  they  are  prosecuted  with  a  full  knowledge  of  all  the  precautions 
necessary  to  insure  success.  Some  of  these  will  be  here  explained. — Tn  the  first 
place,  the  endowments  of  the  trunk  and  of  the  roots  of  a  nerve  may  differ;  owing 
to  the  admixture,  in  the  former,  of  fibres  derived  by  inosculation  from  another 
nerve  (§  473).  Hence,  in  order  to  attain  satisfactory  results,  a  comparative  set 
of  experiments  should  always  be  made  upon  each. — A  nerve-trunk  may  be  too 
hastily  considered  as  motor,  on  account  of  the  excitation  of  muscular  movements 
by  irritation  of  its  trunk,  whilst  still  in  connection  with  its  centre ;  for  such 
movements  may  be  called-forth,  not  only  by  the  direct  influence  of  the  nerve 
upon  the  muscles,  but  also  by  reflex  stimulation,  acting  through  the  ganglionic 
centre  upon  some  other  nerve.  The  real  nature  of  such  movements  can  only  be 
determined  by  dividing  the  trunk,  and  then  irritating  each  of  the  cut  extremi- 
ties. If,  upon  irritating  the  end  separated  from  the  centre,  muscular  contrac- 
tions are  produced,  it  may  be  safely  inferred  that  the  nerve  is  in  part  at  least,  of 
an  efferent  character.  Should  no  such  result  follow,  this  would  be  improbable. 
If,  on  the  other  hand,  muscular  movement  should  be  produced  by  irritating  the 
extremity  in  connexion  with  the  centre,  it  will  then  be  evident,  that  it  is  occa- 
sioned by  an  impression,  conveyed  towards  the  centre  by  this  trunk,  and  propa- 
gated to  the  muscles  by  some  other ;  in  other  words,  to  use  the  language  of  Dr. 
M.  Hall,  this  nerve  is  an  'excitor'  of  motion,  not  a  direct  motor  nerve.  The 
Glosso-pharyngeal  has  been  satisfactorily  determined,  by  experiments  of  this  kind, 
performed  by  Dr.  J.  Reid  (§  81),  to  be  chiefly,  if  not  entirely,  an  afferent  nerve. 
— It  has  been  from  the  want  of  a  proper  mode  of  experimenting,  that  the  func- 
tions of  the  posterior  roots  of  the  Spinal  nerves  have  been  regarded  as  in  any 
degree  motor.  If  they  be  irritated,  without  division  of  either  root,  motions  are 
often  excited ;  but  if  they  be  divided,  and  their  separated  trunks  be  then  irri- 
tated, no  motions  ensue ;  nor  are  any  movements  produced  by  irritation  of  the 
roots  in  connexion  with  the  spinal  cord,  if  the  anterior  roots  have  been  divided. 
Hence  it  appears  that  these  fibres  do  not  possess  any  direct  motor  powers,  but 
that  they  convey  impressions  to  the  centre,  which  are  reflected  to  the  muscles 
through  the  anterior  roots. — The  same  difficulties  do  not  attend  the  determination 
of  the  sensory  endowments  of  nerves.  If,  when  the  trunk  of  a  nerve  is  pricked 
or  pinched,  the  animal  exhibits  signs  of  pain,  it  may  be  concluded  that  the  nerve 
MS  capable  of  receiving  and  transmitting  sensory  impressions  from  its  peripheral 
extremity.  But  it  happens  not  unfrequently,  that  this  capability  is  derived  by 
inosculation  with  another  nerve ;  as  is  the  case  with  the  Facial,  which  is  sensory 
after  it  has  passed  through  the  parotid  gland,  having  received  there  a  twig  from 
the  Fifth  pair.  A  similar  inosculation  explains  the  apparent  sensibility  of  the 
anterior  roots  of  the  Spinal  nerves.  If  these  be  irritated,  the  animal  usually 
gives  signs  of  uneasiness;  but  if  they  be  divided,  and  the  cut-ends  nearest  the 
centre  be  irritated,  none  such  are  exhibited  j  whilst  they  are  still  shown  when  the 
farther  ends  are  irritated,  but  not  if  the  posterior  roots  are  divided.  This  seems 
to  indicate  that  from  the  point  of  junction  of  the  two  roots,  sensory  fibres  derived 
from  the  posterior  roots  pass  backwards  (or  towards  the  centre)  in  the  anterior  j 


DETERMINATION    OF   THE   FUNCTIONS    OF   NERVES.  447 

and  that  the  apparent,  sensory  endowments  of  the  latter  are  entirely  dependent 
upon  their  connexion  with  the  posterior  column  of  the  spinal  cord,  through  the 
posterior  roots. 

478.  The  fallacies   to  which  all   experiments  upon  the  nerves  are  subject, 
arising  from  the  partial  loss  of  their  power  of  receiving  and  conveying  impres- 
sions, and  of  exciting  the  muscles  to   action,  after  death,  are  too  obvious  to 
require  more  particular  mention  here ;  yet  they  are  frequently  overlooked.      Of 
a  similar  description  are  those  arising  from  severe  disturbance  of  the  system,  in 
consequence  of  operations  j  which  also  have  not  been  enough  regarded  by  ex- 
perimenters.— As  a  general  rule,  negative  results  are  of  less  value  than  positive; 
but  very  careful  discrimination  is  often  required  to  determine  what  are  negative, 
and  what  positive  results.     Each  particular  case  has  its  own  sources  of  fallacy, 
which    require   to  be   logically  scrutinized ;  and   the   only  satisfactory  proof  is 
derived  from  the  concurrence  of  every  kind  of  evidence,  which  the  nature  of 
the  inquiry  admits-of.     Thus  in  the  determination  of  the  functions  of  a  parti- 
cular nerve-trunk,  it  should  be  shown  that  a  certain  effect  is  constantly  produced 
by  its  excitation  (under  the  conditions  laid-down  in  the  preceding  paragraph), 
and  that  a  corresponding  interruption  in  the  action  to  which  it  is  hence  inferred 
to  be  subservient,  takes  place  when  its  continuity  has  been  interrupted :  by  this 
double  proof,  the  Glosso-pharyngeal  and  the  Pneumogastric  are  shown  to  be  the 
principal,  but  not  the  sole,  excitors  of  the  movements  of  Deglutition  and  Inspi- 
ration respectively.     But  the  evidence  afforded  solely  by  the  interruption  of  a 
particular  function,  after  the  division  of  a  certain  nerve,  or  the  destruction  or 
removal  of  a  nervous  centre,  is  by  no  means  so  satisfactory ;  for  this  may  be 
occasioned  rather  by  the  general  effects  of  the  operation,  than  by  the  simple 
lesion  of  the  nervous  apparatus.     In  order  to  get  rid,  so  far  as  possible,  of  this 
source  of  fallacy  (which  particularly  affects  experiments  upon  the  Encephalic 
centres,  and  upon  the  influence  of  the  nerves  upon  the  viscera),  it  is  desirable  to 
perform  comparative  experiments,  in  which  the  general  injury  shall  be  as  nearly 
as  possible  the  same,  and  the  only  difference  shall  lie  in  the  lesion  of  the  nervous 
system ;  and  to  subtract  from  the  entire  result  all  that  can  be  thus  shown  to  be 
attributable  to  the  general  disturbance  produced  by  the  operation.     But  even 
then,  it  may  happen  that  the  function  is  only  suspended  for  a  time,  by  the  shock 
which  has  been  induced  by  the  injury  to  the  nerve;  and  if  it  should  be  subse- 
quently renewed,  without  any  reunion  of  the  trunk,  we  have  the  most  convincing 
proof  that,  whatever  degree    of  participation  the  nerve  may  have  in  it,  the 
action  is  not  essentially  dependent  upon  the  integrity  of  that  portion  of  the 
nervous  apparatus.     Such  we  have  seen  to  be  the  case,  in  regard  to  the  relation 
of  the  Pneumogastric  nerves  to  the  secretion  of  gastric  fluid  in  the  walls  of  the 
stomach  (§§  101-103). 

479.  All  our  positive  knowledge  of  the  functions  of  the  Nervous  System  in 
general,  save  that  which  results  from  our  own  consciousness  of  what  passes  within 
ourselves,  and  that  which  we  obtain  from  watching  the  manifestations  of  disease 
in  Man,  is  derived  from  observation  of  the  phenomena  exhibited  by  animals 
made   the  subjects  of  experiments ;  and  in  the  interpretation  of  these,  great 
caution  must  be  exercised. — In  the  first  place  it  must  be  constantly  borne  in 
mind,  that,  except  through  the  movements  consequent  upon  them,  we  have  no 
means  of  ascertaining,  whether  or  not  particular  changes  in  the  Nervous  System, 
whose  character  we  are  endeavouring  to  determine,  are  attended  with  Sensation; 
since  we  have  no  power  of  judging  whether  or  not  this  has  been  excited,  save 
by  the  cries  and  struggles  of  the  animal  made  the  subject  of  experiment.     Now 
although  such  cries  and  struggles  are  ordinarily  considered  as  indications  of  pain, 
yet  it  is  not  right  so  to  regard  them  in  every  instance ;  and  the  only  unequivocal 
evidence  is  derived  from  observation   of  the  corresponding  phenomena  in  the 
Human  subject;  since  we  can  there  ascertain,  by  the  direct  testimony  of  tho 
individual  affected,  what  impressions  produce  sensation,  and  what  excite  move- 


448  FUNCTIONS   OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

ments  independently  of  sensation  (§§  506-509).  Further,  we  are  not  justified 
in  assuming  that  Consciousness  is  excited  by  an  irritation,  still  less  that  Intelli- 
gence and  Will  are  called  into  exercise  by  it,  merely  because  movements,  evidently 
tending  to  get  rid  of  its  source,  are  performed  in  respondence  to  it.  We  know 
that  the  contractions  of  the  heart  and  alimentary  tube  are  ordinarily  excited  by 
a  stimulus,  without  any  sensation  being  involved ;  and  these  movements,  like  all 
that  are  concerned  in  the  maintenance  of  the  Organic  functions,  have  an  obvious 
design,  when  considered  either  in  their  immediate  effects,  or  in  their  more  remote 
consequences.  The  character  of  adaptiveness,  then,  in  Muscular  movements 
excited  by  external  stimuli,  is  no  proof  that  they  are  performed  in  obedience  to 
sensation  ;  much  less  that  they  have  a  voluntary  character.  In  no  case  is  this 
adaptiveness  more  remarkable,  than  in  some  of  those  actions,  which  are  not  only 
performed  without  any  effort  of  the  will,  but  which  the  will  cannot  imitate.  This 
is  the  case,  for  example,  with  the  act  of  Deglutition  (§§  81,  82),  the  muscles 
concerned  in  which  cannot  be  thrown  into  contraction  by  a  voluntary  impulse, 
being  stimulated  only  by  impressions  conveyed  from  the  mucous  surface  of  the 
fauces  to  the  Medulla  Oblongata,  and  thence  reflected  along  the  motor  nerves. 
No  one  can  swallow,  without  producing  an  impression  of  some  kind  upon  this 
surface,  to  which  the  muscular  movements  will  immediately  respond.  Now  it  is 
impossible  to  conceive  any  movements  more  perfectly  adapted  to  a  given  purpose, 
than  are  those  of  the  parts  in  question ;  and  yet  they  are  independent,  not  only 
of  volition  but  of  sensation,  being  still  performed  in  cases,  in  which  consciousness 
is  completely  suspended,  or  entirely  absent.  The  act  of  Sucking  in  the  infant, 
again,  is  one  in  which  a  number  of  muscles  are  called  into  combined  contraction, 
in  a  manner  which  shows  a  complete  adaptation  to  a  given  purpose ;  and  yet  it 
is  impossible  to  suppose  this  adaptation  to  be  purposive  on  the  part  of  the  infant 
itself;  more  especially  as  it  is  shown,  both  by  the  occurrence  of  monstrosities, 
and  by  experiments  made  with  this  object  (§  77),  that  no  part  of  the  Cranio-spinal 
axis  above  the  Medulla  Oblongata  is  necessary  to  it.  And  in  the  acts  of  Cough- 
ing and  Sneezing  (§  306),  we  have  additional  examples  of  the  most  adaptive 
movements,  executed  by  a  marvellous  combination  of  separate  muscular  actions, 
with  the  obvious  purpose  of  removing  sources  of  irritation  from  the  air-passages; 
and  yet  we  know  by  personal  experience,  that  this  combination  is  not  made  with 
any  design  of  our  own. 

2.    Of  the  Spinal  Cord  and  Medulla  Oblongata; — their  Structure  and  Actions. 

480.  In  our  more  detailed  consideration  of  the  functions  of  the  several  divi- 
sions of  the  Nervous  System,  it  is  desirable,  for  several  reasons,  to  commence 
with  the  Cranio- Spinal  Axis;  which,  as  already  pointed-out  (§  464),  may  be 
considered  as  constituting  the  fundamental  portion  of  this  apparatus.     The  entire 
Axis  is  divided  into  its  Cranial  and  its  Spinal  portions,  the  passage  of  the  Cord 
through  the  '  foramen  magnum'  of  the  occipital  bone  being  considered  to  mark 
the  boundary  between  them ;  and  although  the  separation  of  the  Medulla  Spi- 
nalis  from  the  Medulla  Oblongata,  which  is  thus  established,  is  in  itself  purely 
artificial,  yet  it  will  be  found  to  correspond  completely  with  the  natural  division 
founded  on  their  respective  physiological  attributes. 

481.  The  Spinal  Cord,1  which  extends  from  the  margin  of  the  foramen  mag- 
num to  the  first  or  second  lumbar  vertebra,  and  which  is  prolonged  as  the  filum 
terminal^  to  the  extremity  of  the  sacral  canal,  is  almost  completely  divided  by 
the  anterior  and  posterior  median  fissures  (Fig.  126,  or,  p~),  into  two  lateral  and 

1  The  sketch  given  in  the  text  of  the  Anatomy  of  the  Spinal  Cord,  is  chiefly  derived  from 
the  statements  of  Prof.  Kollikerin  his  "  Mikroskopische  Anatomic"  (Band  n.  %%  115,  116), 
and  of  Mr.  J.  L.  Clarke  in  the  "Philosophical  Transactions,"  1851  and  1852;  between 
which  there  is  a  general  accordance. 

2  The  structure  of  the  '  filum  terminale '  is  in  every  respect  essentially  the  same  as  that 
?f  the  proper  Spinal  Cord,  save  that  no  nerve-roots  are  connected  with  it. 


STRUCTURE    OF    SPINAL    CORD. 


449 


Tranverse  section  of  Human  Spinal  Cord,  through  the  middle  of  the  Inmbar  enlargement, 
(Showing  on  the  right  side  the  course  of  the  nerve-roots,  and  on  the  left  the  position  of  the 
piincipal  tracts  of  vesicular  matter: — A,  A,  anterior  columns ;  p,  p,  posterior  columns;  L,  L, 
lateral  columns;  a,  anterior  median  fissure;  p,  posterior  median  fissure;  b,  b,  b,  b,  anterior 
roots  of  spinal  nerves ;  c,  c,  posterior  roots ;  d,  d,  tracts  of  vesicular  matter  in  anterior 
column;  e,  tracts  of  vesicular  matter  in  posterior  column;  /,  spinal  column;  g,  substantia 
gelatinosa. 

symmetrical  halves.  The  '  anterior  median  fissure'  (a)  is  more  distinct  than  the 
posterior,  being  wider  at  the  surface ;  but  it  only  penetrates  to  about  one-third 
of  the  thickness  of  the  Cord,  its  depth  increasing,  however,  towards  its  lower 
part.  The  sides  of  the  '  posterior  median  fissure'  (p),  on  the  other  hand,  are  in 
closer  approximation  j  but  the  division  commonly  extends  to  about  half  the  thick- 
ness of  the  cord,  being  deeper  towards  its  upper  than  towards  its  lower  end. 
The  two  halves,  therefore,  are  only  united  by  a  commissural  band,  which  occu- 
pies the  central  part  of  the  cord ;  and  this  is  traversed  by  the  '  Spinal  canal'  (/), 
which  is  continued  downwards  from  the  fourth  ventricle.1  At  a  little  distance 
from  either  side  of  the  posterior  median  fissure,  and  corresponding  with  the  line 
of  attachment  of  the  posterior  roots  of  the  nerves,  is  the  posterior  lateral  fur- 
row ;  a  shallow  longitudinal  depression,  which  marks-out  the  '  posterior  columns' 
of  the  Cord  (p,  p),  as  distinct  from  the  '  antero-lateral  columns.'  A  correa 
ponding  furrow  has  been  sometimes  described  as  traversing  the  Cord  in  the 
line  of  the  anterior  roots  of  the  nerves  on  either  side  j  but  this  can  scarcely 
be  said  to  have  a  real  existence;  and  the  separation  of  the  ' antero-lateral 
columns  into  the  anterior  and  lateral  columns  (A  A  and  L  L)  is  only  marked 
externally  by  the  attachment  of  the  nerve-roots.  It  is  made  more  obvious  in- 
ternally, however,  by  the  peculiar  distribution  of  the  grey  matter ;  which,  though 
by  no  means  uniform  throughout  the  Cord,  usually  presents  (in  a  transverse  sec- 
tion) the  form  of  two  somewhat  crescent-shaped  masses,  whose  convexities  are 
turned  towards  each  other,  and  are  connected  by  the  grey  commissure,  whilst 

1  The  canal  can  only  be  distinguished  in  Man  (being  no  more  than  l-100th  of  an  inch 
in  diameter),  by  submitting  thin  transverse  sections  of  the  Cord  to  microscopic  examina- 
tion ;  whence  it  happens  that  its  existence  in  the  adult  has  been  denied  by  Kolliker  and 
many  eminent  anatomists.  Its  presence  is  much  more  obvious,  however,  in  Fishes ;  in 
whose  spinal  cord  the  commissural  connection  between  the  two  lateral  halves  is  far  less 
distinct  than  in  higher  Vertebrata. 

29 


450 


FUNCTIONS   OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 


their  cornua  are  directed  towards  the  surface  of  the  cord ; 
the  posterior  peak  on  each  side  nearly  reaches  the  poste- 
rior lateral  furrow,  whilst  the  anterior,  though  the  larger 
cornu,  does  not  approach  quite  so  near  the  surface. 
The  grey  matter  is  enveloped  by  the  white  substance 
of  the  columns,  which  are  entirely  composed  of  nerve- 
tubes,  whose  general  direction  is  longitudinal. — The 
Spinal  Cord  of  Man  is  by  no  means  of  uniform  dimen- 
sions in  every  part  of  its  length  ;  and  the  proportions 
which  the  grey  and  white  substances  bear  to  one  an- 
other in  different  parts,  are  extremely  diverse  (Fig. 
126).  Two  principal  enlargements  are  seen  in  the 
cervical  and  lumbar  regions,  at  the  origins  of  the 
large  nerves  forming  the  tracheal  and  crural  plexuses ; 
and  these  enlargements  are  chiefly  due  to  an  increase 
of  the  grey  substance,  which  is  comparatively  deficient 
in  the  intervals.  On  the  other  hand,  there  is  a  regu- 
larly-progressive increase  in  the  white  substance,  as  we 
proceed  from  the  lower  to  the  higher  portion  of  the 
cord;1  and  this  fact  of  itself  serves  to  indicate  the 
probability,  that  the  longitudinal  columns  serve  (as 
formerly  supposed)  to  establish  a  direct  connection  be- 
tween the  Encephalic  centres  and  the  roots  of  the 
Spinal  nerves. 

482.  The  grey  matter  or  vesicular  substance  of  the 
Spinal  Cord,  which  is  best  seen  in  transverse  section 
(Fig.  126),  is  by  no  means  uniform  in  its  texture 
throughout.  Its  anterior  cornua,  which  are  thicker 
and  shorter  than  the  posterior,  are  of  a  uniform  grey 
colour;  and  they  consist  of  large  well-developed  nerve- 
cells  ((/),  which  usually  present  many  radiating  pro- 
cesses  that  seem  to  inosculate  together,  with  deli- 
Transverse  sections  of  the  cate  nerve-fibres  of  medium  fineness  passing  in  various 
gpinal  cord;  A.  Immediately  directions  between  them.  The  central  portion,  which 
below  the  decussation  of  the  contains  the  canal,  and  which  also  forms  the  commis- 
pyramids .  — B.  At  middle  of  ^^  has  a  similar  composition:  but  the  cells  are 
t™ ce±alCafd \  lumllr  smaller,  though  still  having  long  branching  radiations; 
bulbs.  D.  Lumbar  bulb.  E.  and  the  fibres  are  extremely  fine,  their  tubularity 
An  inch  lower.  F.  Very  near  being  often  indistinguishable.  The  anterior  portion 
the  lower  end.  a.  Anterior  Of  j^e  commissure,  however,  is  purely  fibrous,  and  is 
surface,  p.  Posterior  surface.  distinguished  by  gome  ag  the  t  white  commissure ;'  it 
The  points  of  emergence  of  ,  ,  J  ~  ,.  ,  ',. 

the  anterior  and  posterior  does  not>  however,  form  an  immediate  connection 
roots  of  the  nerves  are  also  between  the  two  anterior  columns,  but  brings  each 
seen.  of  them,  as  will  be  presently  seen,  into  relation  with 

the  vesicular  matter  of  the  anterior  cornu  of  the  oppo- 
site side.     The  posterior  cornua,  longer  and  narrower  than  the  anterior,  con- 

1  See  Kolliker's  "  Mikroskopische  Anatomic,"  band  ii.  g  116,  and  "Manual  of  Human 
Histology"  (Sydenham  Society),  vol.  i.  p.  420. — The  statements  in  the  text  are  in  direct 
contradiction  to  the  assertions  of  Volkmann  (Art.  '  Nervenphysiologie'  in  "  Wagner's 
Handworterbuch,"  band  ii.  pp.  482,  et  seq.) ;  who  affirms  that  the  grey  and  white  sub- 
stances everywhere  bear  the  same  proportion  one  to  the  other,  and  that  there  is  absolutely 
less  white  matter  high-up  in  the  neck,  than  there  is  lower-down  in  the  cord.  But  his  mea- 
surements were  made  upon  the  Spinal  Cord  of  the  Horse ;  and  it  seems  not  improbable, 
from  the  considerations  to  be  hereafter  stated  (§  487),  that  there  may  be  an  essential  dif 
ference  between  Man  and  the  lower  Animals,  as  to  the  proportion  which  the  root-fibres 
terminating  in  the  Spinal  Cord  itself,  bear  to  those  which  pass  between  the  roots  of  the 
nerves  and  the  Encephalon. 


STRUCTURE    OF    SPINAL    CORD. 


451 


tain  a  tract  of  vesicular  matter  (e)  on  each 
side,  the  cells  of  which  resemble  those  of  the 
central  portion  ;  this  tract  is  invested  by  a 
more  transparent  layer,  which  has  been  dis- 
tinguished as  the  subsfantia  gelatinosa  ;  but 
the  composition  of  the  latter  only  differs  from 
that  of  the  former  in  the  smaller  size  of  the 
nerve-cells,  both  having  a  large  admixture 
of  fine  fibres.  In  no  case  has  a  direct  con- 
tinuity been  distinguished  between  the  nerve- 
fibres  and  the  vesicles  or  their  prolongations ; 
though  there  are  circumstances  which  seem 
to  render  such  a  conclusion  probable. 

483.  The  connection  of  the  Nerve-roots 
of  the  Spinal  Nerves  with  the  several  com- 
ponents of  the  Cord,  and  the  course  of  the 
fibres  after  entering  it,  can  only  be  made-out 
by  means  of  sections;  since  all  attempts  to 
follow  the  course  of  individual  fibres,  or  even 
that  of  fasciculi,  by  ordinary  dissection,  have 
as  yet  proved  quite  futile.1  The  following 
is  an  outline  of  the  information  which  may 
thus  be  gained,  from  a  comparison  of  trans- 
verse and  longitudinal  sections  (Figs.  126  and 
128). — The  bundles  that  form  the  Posterior 
roots  (Fig.  126,  c,c.  Fig.  128,  p,  p,  p),  consist 
of  three  kinds,  which  differ  from  each  other 
partly  in  direction,  and  partly  in  the  size  of 
their  component  filaments.  The  first  kind, 
Fig.  128,  a,  a,  a,  (which  seem  to  be  limited 
to  the  upper  part  of  the  Cord)  enter  the 
posterior  columns  horizontally;  and  then, 
taking  a  longitudinal  direction  down  the 
Cord,  send  fibres  into  the  anterior  grey  sub- 
stance (G),  of  which  some  bend  upwards, 
and  others  downwards ;  part  apparently  be- 
coming continuous  with  fibres  of  the  ante- 
rior roots;  whilst  another  part  lose  them- 
selves among  the  fibres  of  the  anterior 
columns,  in  which  they  may  either  proceed 
continuously  to  the  head,  or  may  pass-along 
for  a  limited  distance  only,  to  emerge  in 
the  nerve-roots  of  some  other  segment.  The 
second  kind  of  bundles,  b,  b,  b,  also  traverse 
the  posterior  columns  horizontally  and  ob- 
liquely inwards;  their  further  course  may 
be  best  traced  in  a  transverse  section  (Fig. 
126).  These  fasciculi,  which  are  composed 
of  remarkably  fine  and  delicate  fibres,  inter- 
lace so  as  to  form  with  each  other  an  intri- 
cate plexus;  and  from  this,  straight  and 
distinct  bundles  enter  the  posterior  cornua 


FIG.  128. 


Longitudinal  Section  through  Cervical 
enlargement  of  Spinal  Cord  of  Cat : — 
A  C,  anterior  white  columns;  AC'  portion 
showing  the  arrangement  of  the  longitudi- 
nal fibres  ;  p  c,  posterior  white  columns  ; 
G,  grey  substance  between  them  (the  ve- 
sicles omitted,  to  avoid  obscuring  the  course 
of  the  fibres);  A,  anterior  roots  of  the 
nerves ;  p,  posterior  roots,  consisting  of 
three  kinds,  the  first,  a,  crossing  the  poste- 
rior columns  horizontally,  and  then  passing 
obliquely  downwards,  across  the  grey  sub- 
stance, into  the  anterior  columns ;  the 
second,  b,  traversing  the  posterior  columns 
horizontally,  and  then  distributing  them- 
selves through  the  grey  substance;  the 
third,  c,  for  the  most  part  becoming  con- 
tinuous with  the  longitudinal  fibres  of  the 
posterior  column. 


1  Mr.  J.  L.  Clarke  has  succeeded,  by  the  adoption  of  a  peculiar  method  of  preparation 
(for  which  see  "Phil.  Trans.,"  1851,  p.  607),  in  making  sections  of  considerable  dimen 
sions,  sufficiently  transparent  to  allow  the  course  of  the  fibres,  and  the  contour  of  the 
nerve-cells  and  their  prolongations,  to  be  distinctly  made-out. 


452          FUNCTIONS   OF   THE   CEREBRO-SPINAL    NERVOUS    SYSTEM. 

along  their  whole  breadth,  crossing  the  'substantia  gelatinosa'  both  obliquely  and 
at  right  angles.  Having  thus  entered  the  vesicular  substance  of  the  Cord,  some 
of  the  fibres,  after  traversing  it,  emerge  from  it  again,  into  either  the  posterior 
columns,  or  the  posterior  portion  of  the  lateral  columns  ;  others  pass  towards  the 
transverse  commissure,  through  which  they  seem  to  make  their  way  to  the  poste- 
rior and  lateral  columns  of  the  opposite  side;  and  others,  again,  form  a  fine 
network,  which  extends  towards  the  anterior  cornua.  Of  the  fibres  of  a  third 
set  (Fig.  128,  c,  c,  c),  a  part  seem  to  become  directly  continuous  with  the  fibres 
of  the  posterior  columns ;  the  larger  proportion  of  them,  however,  cross  these 
columns  obliquely  upwards,  and  enter  the  grey  substance  at  different  points; 
after  passing  into  which,  they  can  no  longer  be  clearly  followed,  although  some 
of  them  appear  to  form  loops  and  then  return  to  the  white  columns. — The  fasci- 
culi of  fibres  which  constitute  the  anterior  roots  (Fig.  126,  ft,  b,  b,  Fig.  128,  A,  A), 
on  the  other  hand,  traverse  the  anterior  columns  of  the  Cord  nearly  horizontally, 
and  in  straight  and  distinct  bundles,  which  do  not  interlace  with  each  other, 
until  they  reach  the  anterior  cornu  of  the  grey  substance ;  on  entering  this,  they 
break-up  into  smaller  bundles  and  separate  fibres,  which  diverge  in  various 
directions ;  some  pass-out  again  into  the  anterior,  and  others  into  the  lateral 
columns  of  the  same  side;  others,  again,  pass  towards  the  anterior  part  of  the 
commissure,  in  which  they  cross-over  to  the  opposite  side,  entering  its  anterior 
and  lateral  columns ;  a  considerable  number  plunge  into  the  central  substance 
of  the  grey  cornu,  and  of  these  some  become  longitudinal,  passing  equally  upwards 
and  downwards,  whilst  others  seern  to  traverse  it  horizontally,  so  as  to  come  into 
relation  (not  improbably  into  actual  continuity)  with  the  posterior  roots. 

484.  Thus  we  see  that  there  are  two  very  distinct  courses  pursued  by  the  Root- 
fibres  of  the  Spinal  Nerves,  in  the  substance  of  the  Cord ;  the  first  transverse, 
the  second  longitudinal.  The  fibres  belonging  to  the  former  category  traverse 
the  Cord  horizontally  or  obliquely,  and  appear  to  pass-out  in  the  other  set  of 
roots  connected  with  the  same  segment,  either  on  its  own  or  on  the  opposite  side 
cf  the  median  fissure.  Of  those  belonging  to  the  latter,  a  small  part  appears  to 
connect  the  posterior  roots  directly  with  the  posterior  columns,  without  passing 
into  the  vesicular  substance ;  but  the  remainder  of  those  belonging  to  the  poste- 
rior roots,  first  enter  the  grey  matter  of  the  Cord,  and  then  emerge  from  it  either 
into  the  posterior  column,  or  into  the  posterior  part  of  the  lateral  column,  of 
their  own  or  of  the  opposite  half  of  the  Cord;  and,  in  like  manner,  all  the  lon- 
gitudinal fibres  belonging  to  the  anterior  roots  first  enter  the  vesicular  substance, 
and  then  pass-out  from  it  into  the  anterior  column,  or  the  anterior  part  of  the 
lateral  column,  of  the  same  or  of  the  opposite  side.  How  far  any  of  these  lon- 
gitudinal fibres  proceed,  however,  either  upwards  or  downwards  in  the  Cord, 
must  be  acknowledged  to  be  altogether  undecided.  It  seems  quite  probable  that 
some  of  them  are  (so  to  speak)  properly  longitudinal  commissures,  serving  to 
connect  the  nerve-roots  of  one  segment  of  the  Cord,  with  the  vesicular  substance 
of  another  at  a  greater  or  less  distance  either  above  or  below ;  and  it  has  been 
recently  maintained  by  several  distinguished  Neurologists,  that  all  must  probably 
be  of  this  character,  so  that  the  Spinal  Cord  is  the  real  centre  of  all  the  nerve- 
fibres  connected  with  it.  The  principal  argument  for  this  doctrine  (which  seems 
to  have  originated  with  the  anatomical  researches  of  Stilling  and  Wallach,1  and 
to  have  been  first  put-forth  on  a  physiological  basis  by  Messrs.  Todd  and  Bow- 
inan2),  arises  from  the  asserted  difficulty  of  supposing  that  its  longitudinal 
columns  can  transmit  any  considerable  number  of  nerve-fibres  from  the  Ence- 
phalon  to  the  Spinal  nerve-roots.  Thus  it  is  urged  by  Dr.  Todd,  that  it  is  highly 
improbable  that  the  only  channel  by  which  the  Will  can  influence  the  spinal 
nerves,  should  be  (as  generally  admitted)  that  afforded  by  the  Anterior  Pyra- 

1  "  Untersuchungen  iiber  die  Textur  des  Riickenmarks,"  Leipzig,  1842. 
a  "Physiological  Anatomy  and  Physiology  of  Man,"  Part  ii.,  1845. 


STRUCTURE    OF    THE    SPINAL    CORD.  453 

niids;  since  the  whole  bulk  of  these  pyramids  on  both  sides,  taKen  together, 
scarcely  equals  that  of  one  of  the  anterior  portions  of  the  antero-lateral  columns. 
Moreover,  if  there  were  a  gradual  giving-off  of  Encephalic  fibres  from  the  Ion-  , 
gitudinal  columns  into  the  roots  of  the  nerves,  the  size  of  these  columns  ought 
progressively  to  diminish  from  above  downwards ;  whereas  it  is  asserted  by  Yolk- 
mann,  who  has  strenuously  upheld  this  doctrine  (loc.  cit.),  that  the  size  of  the 
white  columns  presents  no  such  diminution,  but  that  it  is  everywhere  proportional 
to  the  quantity  of  grey  matter  in  the  Cord.  Thus  in  Serpents,  the  Spinal  cord 
(as  already  noticed)  is  remarkable  for  its  uniformity  of  dimension  through  its 
entire  length,  the  absence  of  limbs  preventing  the  necessity  for  an  increase  in 
the  quantity  of  grey  matter  in  any  part,  and  the  fibrous  columns  presenting  a 
similar  uniformity  throughout ;  whereas,  if  the  latter  be  really  Encephalic,  they 
should  gradually  dwindle-away  from  the  head  to  the  tail.  Moreover  it  has  been 
estimated  by  Volkrnann,  that  the  area  of  the  whole  Spinal  Cord  of  a  Boa,  at  its 
anterior  part,  is  not  more  than  one-eleventh  part  of  the  united  area  of  the  221 
pairs  of  nerves  which  are  given-off  from  it.  Further  it  is  urged  by  Volkmann, 
that  the  white  columns  are  absolutely-smaller  in  the  cervical  region,  than  they 
are  in  the  lower  part  of  the  Cord ;  so  that  they  would  not  suffice  to  convey  even 
the  lumbar  columns  upwards  to  the  Encephalon,  much  less  to  transmit  the  fibres 
of  all  the  intervening  nerves  in  addition. 

485.  These  and  similar  statements,  however,  have  been  recently  met  by  Prof. 
Kolliker  (loc.  cit.),  whose  researches  have  led  him  to  a  conclusion  opposed  to 
that  of  Volkmann,  although  he  was  at  one  time  inclined  to  coincide  with  it.     He 
has  assured  himself  that  in  Man,  the  thickness  of  the  white  columns  does  aug- 
ment from  below  upwards,  and  that  the  increase  in  the  diameter  of  the  Cord  at 
the  ganglionic  enlargements  is  due  to  the  augmentation  of  the  grey  matter  only. 
Moreover,  the  diameter  of  the  nerve-tubes  in  the  Cord,  especially  at  its  upper 
part,  is  so  much  smaller  than  the  diameter  of  the  nerve-tubes  of  the  Nerve-roots, 
that  a  large  allowance  must  be  made  for  this  difference,  in  estimating  the  relative 
number  of  nerve-tubes  in  the  fibrous  columns  of  the  Cord  and  in  the  spinal 
Nerves  ;  and  he  asserts  from  actual  measurement,  that  it  is  by  no  means  impos- 
sible for  the  fibrous  strands  of  the  former  to  contain  all  the  nerve-tubes  which 
issue  from  them  in  the  latter.     He  has  found  himself  unable,  moreover,  to  detect 
any  termination  of  the  nerve-fibres  in  the  vesicular  substance  of  the  spinal  cord; 
and  hence  he  thinks  it  probable  that  they  all  pass  upwards  to  the  brain. — On  the 
other  hand,  the  researches  of  Mr.  J.  L.  Clarke,  which  have  been  carried  in  some 
respects  to  a  greater  degree  of  minuteness  than  those  of  Prof.  Kolliker,  seem  to 
confirm  the  belief  that  there  is  a  set  of  fibres  which  never  become  longitudinal, 
and  which,  accordingly,  have  no  other  ganglionic  centre  than  the  vesicular  sub- 
stance of  the  segment  of  the  Cord  with  which  they  come  into  immediate  rela- 
tion ;  whilst  they  also  accord  with  those  of  Prof.  Kolliker  in  rendering  it  ex- 
tremely probable,  that  many  of  the  longitudinal  fibres  of  both  roots,  do  pass 
continuously  upwards  to  the  Encephalon,  most  of  them  after  traversing  the  grey 
nucleus,  but  some  of  those  of  the  posterior  roots  without  even  entering  the  vesi- 
cular substance,  so  that  these  cannot  have  their  ganglionic  centre  in  the  Cord  at 
all.     If  the  latter  be  among  the  fibres  which  pass-up  through  the  Posterior  Pyra- 
mids into  the  sensory  tract  of  the  Crura  Cerebri  (§  490),  their  real  ganglionio 
centres  are  the  Thalami  Optici. 

486.  That  such  is  the  real  arrangement,  is  very  strongly  indicated  by  the 
analogous  conformation  of  the  gangliated  cord  of  Articulated  animals ;    for  it 
may  be  stated  with  tolerable  certainty,  that  some  of  the  root-fibres  of  their  nerves 
pass  along  the  purely-fibrous  tract  of  that  cord  (which  is  far  more  readily  sepa- 
rated from  the  vesicular,  than  it  can  be  in  Vertebrata),  directly  to  the  cephalic 
ganglia,  which  they  thus  bring  into  direct  communication  with  all  the   nerve- 
trunks  connected  with  the  gangliated  cord;  but  that  others,  also  becoming  lon- 
gitudinal, and  running  along  those  portions  of  the  cord  which  intervene-between 


454  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

and  connect  the  ganglia  of  the  different  segments,  pass  into  the  nerve-trunks  that 
emerge  from  ganglia  at  a  distance  of  one,  two,  three,  or  more  segments  above  01 
below :  whilst  a  large  proportion  of  the  root-fibres  have  their  ganglionic  centres 
in  the  ganglia  which  they  respectively  enter  ;  and,  after  coming  into  relation  with 
its  vesicular  substance,  pass-out  again,  either  on  the  same  or  on  the  opposite  side 
of  the  median  plane.1  Now  the  purely-fibrous  tract  of  the  ventral  cord  of  the 
Articulata  terminates  in  the  Cephalic  ganglia,  which  are  homologous,  as  already 
remarked  (§  458,  iv.),  not  with  the  whole  Encephalon  of  Vertebrata,  but  with 
their  i sensory  ganglia'  alone;  and  thus  analogy  would  lead  us  to  suppose,  that 
the  fibrous  strands  of  the  Spinal  Cord  do  not  pass-on  continuously  to  the  Cere- 
brum, but  really  extend  no  further  upwards  than  the  Corpora  Striata,  Thalami 
Optici,  and  the  other  ganglionic  centres  in  connection  with  them,  which  lie  along 
the  floor  of  the  cranial  cavity.  This  view  will  be  hereafter  shown  (Sect.  3)  to 
be  in  harmony  with  anatomical  and  physiological  facts,  which  indicate  that  the 
Cerebrum  only  receives  its  impulses  to  action  through  the  medium  of  the  Sen- 
sory G-anglia,  and  that  it  reacts  upon  the  muscular  apparatus  only  through  the 
same  channel.  That  some  of  the  afferent  fibres  of  the  spinal  nerves  should 
ascend  continuously  upwards  to  the  ganglia  of  tactile  sense,  in  Man  and  other 
Vertebrata,  as  well  as  in  Articulated  animals,  would  seem  a  legitimate  deduction 
from  the  fact,  that  such  continuity  obviously  exists  between  the  olfactive,  visual, 
and  auditory  nerves,  and  their  respective  ganglionic  centres,  no  intermediate 
apparatus  of  vesicular  matter  being  interposed  in  their  course;  and,  as  we  have 
seen  (§  483),  the  existence  of  such  a  continuity  in  regard  to  a  part  of  the  fibres 
of  the  posterior  roots  of  the  nerves,  is  made  extremely  probable  by  the  latest 
researches  of  Mr.  J.  L.  Clarke. — A  very  remarkable  confirmation,  too,  has  been 
recently  afforded  to  the  doctrine  of  the  constitution  of  the  Spinal  Cord  here 
advocated,  by  the  Pathological  researches  of  Dr.  Ludwig  Turck ; 2  who  has  shown 
that  certain  lesions  of  the  Encephalon  produce  a  degeneration  of  nerve-tissue  in 
particular  tracks,  which  may  be  traced  continuously  down  the  Spinal  Cord, 
usually  in  the  anterior  column  of  the  side  affected,  and  in  the  lateral  column  of 
the  opposite  side ;  whilst,  on  the  other  hand,  local  lesions  of  the  Spinal  Cord,  as 
from  caries  of  the  vertebrae,  or  from  the  pressure  of  tumours,  produce  a  like 
degeneration  in  certain  tracks  of  the  posterior  columns,  and  sometimes  also  of 
the  lateral  columns,  ascending  towards  the  Encephalon.  Thus  it  appears  that 
the  posterior  fasciculi  are  liable  to  this  secondary  degeneration  in  the  centripetal 
direction  only,  and  the  anterior  in  the  centrifugal  direction  only ;  the  degenera- 
tion taking  place,  in  each  case,  in  the  direction  in  which  they  ordinarily  transmit 
nerve-force.  The  mixed  endowments  of  the  lateral  columns  are  also  indicated 
by  these  phenomena. 

487.  We  are  not  required,  however,  by  the  adoption  of  this  view  of  the  con- 
stitution of  the  Spinal  Cord,  to  regard  its  Cephalic  fibres  as  of  a  different  order 
from  those  which  pass  from  one  of  its  own  segments  to  another  ;  for,  considering 
the  whole  of  the  Cranio-Spinal  axis  as  one  series  of  centres,  receiving  the  termi- 
nations of  all  the  nerves,  its  longitudinal  fibres  are  equally  commissural,  whether 
they  establish  the  connection  between  the  nerve-roots  and  vesicular  matter  of  two 
adjacent  segments,  or  whether  they  bring  into  the  same  structural  relation  the 
parts  which  are  furthest  removed  in  position.  And  thus  we  may  regard  all  im- 
pressions upon  the  afferent  nerves  as  first  operating  upon  it  (affecting  the  con- 

1  See  "  Princ.  of  Comp.  Phys,"  \  648,  Am.  Ed.  —  The  important  facts  here  referred-to, 
have  been  chiefly  substantiated  by  the  researches  of  Mr.  Newport ;  a  very  important  addi- 
tion to  his  statements,  however,  has  been  recently  made  by  M.  Giinther,  who  has  demon- 
strated the  actual  continuity  between  the  nerve-fibres  and  the  caudate  vesicles,  in  the 
ganglia  of  the  ventral  cord  of  the  Leech. 

3  See  his  Memoir  « Uber  secondare  Erkrankung  einzelner  Riickensmarksstrange  und 
*rher  Fortsetzungen  zum  Gehirne,'  in  "  Denschriften  der  Kaiserlichen  Academic  der  Wis- 
benchaften,"  Wien,  1851;  also  "  Zeitschrift  der  Gesell.  der  Aertze  zu  Wien,"  band  ix., 
tteft  10. 


STRUCTURE     OF    MEDULLA    OBLONGATA. 


455 


tfoiousnoss,  or  not,  according  as  they  reach  the  sensory  ganglia,  or  are  arrested  in, 
their  progress  thither);  and  all  motor  impulses,  whether  purely-reflex,  or  origi- 
nating in  volitional  direction  or  emotional  excitement,  as  issuing  immediately 
from  it  through  the  motor  trunks. — If  such  be  the  case,  it  does  not  seem  at  all 
improbable  that  there  should  be  a  difference  in  different  tribes  of  animals,  as  to 
the  proportion  of  fibres  which  have  their  centres  in  the  Spinal  cord  and  in  the 
Sensorial  centres  respectively;  for  in  those  whose  ordinary  movements  of  pro- 
gression, &c.,  are  independent  of  sensation,  being  performed  through  the  reflex 
action  of  the  spinal  cord,  it  might  be  expected  that  the  chief  connexion  of  the 
spinal  nerve  should  be  with  its  own  ganglionic  substance,  and  that  the  bulk  of 
the  fibrous  columns  should  be  composed  of  commissural  fibres  resembling  those 
which  intervene  between  the  separate  portions  of  the  ganglionic  tract  of  the  ven- 
tral cord  of  Articulata;  whilst  in  like  manner  it  might  be  anticipated  that  in 
Man,  so  large  a  part  of  whose  movements  are  performed  in  obedience  to  a  mental 
stimulus  and  under  the  guidance  of  sensation,  the  longitudinal  strands  should  be 
chiefly  composed  of  fibres  that  directly  connect  the  sensorial  centres  with  the  roots 
of  the  spinal  nerves.  Such  a  difference  would  appear,  from  the  comparative 
researches  of  MM.  Volkmann  and  Kolliker,  to  exist  between  the  structure  of  the 
Spinal  cord  of  the  Horse  and  that  of  Man. 

488.  The  Medulla  Otlongata,  or  cranial  prolongation  of  the  Spinal  cord, 
which  bring  it  into  connexion  with  the  Encephalic  centres,  is  distinguished  by 
the  peculiar  arrangement  of  its  fibrous  strands  and  of  its  nuclei  of  grey  matter ; 
and  also  by  the  peculiar  distribution  and  endowments  of  the  nerves  connected 
with  it  (§  510).  The  anatomical  boundaries  usually  assigned  to  it,  are  the  Pona 
Varolii  above,  and  the  Occipital  foramen  below ;  but  these  limits  are  purely  arti- 
ficial ;  and  for  physiological  purposes,  the  course  of  its  fibres  must  be  traced 
much  higher.  The  part  thus  marked-out  has  a  bulb-like  form,  and  presents,  like 
the  Cord  of  which  it  is  the  continuation,  a  posterior  and  an  anterior  median  fis- 
sure, (Figs.  129,  130).  The  former  is  deep  and  narrow,  extending  to  the  poste- 


[Fio.  129. 


[Fie.  130. 
8 


Anterior  view  of  the  medulla 
oblongata;  p,  p.  Pyramidal  bo- 
dies, decussating  at  d.  o,  o.  Oli- 
vary bodies,  r,  r.  Restiform  bo- 
dies, a,  a.  Arciform  fibres,  v. 
Lower  fibres  of  the  Pous  Varolii.] 


Posterior  view  of  the  medulla  oblongata;  pp.  Posterior 
pyramids,  separated  by  the  posterior  fissure,  rr.  Resti- 
form  bodies,  composed  of  cc,  posterior  columns,  and  cM, 
lateral  part  of  the  antero-lateral  columns  of  the  cord.  ua. 
Olivary  columns,  as  seen  on  the  floor  of  the  fourth  ven- 
tricle, separated  by  »,  the  median  fissure,  and  crossed  by 
some  fibres  of  origin  of  nn,  the  seventh  pair  of  nerves.] 


456 


FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 


FIG.  131. 


rior  border  of  a  layer  of  commissural  fibres  which  forms  the  floor  01  the  anterior 
fissure.  The  latter  is  wider  and  less  deep;  and  its  continuity  with  the  anterior 
fissure  of  the  spinal  cord  is  interrupted  by  the  decussation  of  the  Anterior  Pyra- 
mids, which  is  marked  externally  by  the  crossing  of  from  three  to  five  bundles 
of  fibres  from  each  side  over  to  the  other.  This  decussation  may  be  considered 
as  the  physiological  boundary  between  the  Medulla  Oblongata  and  the  Spinal 
Cord.  The  surface  of  each  lateral  half  is  fun-owed  by  grooves,  which  assist  in 
marking-out  the  four  principal  strands  of  nerve-fibres  that  may  be  distinguished 
on  either  side  :  these  are, — I.  The  Anterior  Pyramids,  Corpora  Pyramidalia  ; 
II.  The  Olivary  Bodies,  or  Corpora  Olivaria  ;  in.  The  Restiform  Bodies,  or 
Corpora  Rextiformia  ;  otherwise  called  Processus  a  Cerebello  ad  Medullam  OUon- 
yatam ;  IV.  The  Posterior  Pyramids,  or  Corpora  Pyramidalia  Posteriora. — 
The  connections  of  these  with  the  Brain  above,  and  with  the  Spinal  Cord  below, 
will  be  presently  traced.1  The  vesicular  substance,  on  the  other  hand,  is  prin- 
cipally aggregated  in  three  pairs  of  ganglionic  centres;  of  which  the  anterior 
forms  the  nucleus  of  the  Olivary  body,  the  lateral  of  the  Restiform,  and  the  pos- 
terior of  the  Posterior  Pyramidal. 

489.  The  Anterior  Pyramids  (i)  consist  entirely  of  fibrous  structure,  and 

establish  a  communication  between 
the  <  motor  tract '  (Fig.  131,  m  t) 
of  the  Crura  Cerebri,  and  the  ante- 
rior and  antero-lateral  columns  of 
the  Spinal  Cord.  The  principal 
part  of  their  fibres  decussate ;  and 
these,  as  they  pass  from  above 
downwards,  dip-away  from  the  an- 
terior surface  of  the  Cord,  and  con- 
nect themselves  with  its  middle  or 
lateral  columns,  instead  of  with  ita 
anterior,  as  was  pointed-out  by  Ro- 
senthal,2  and  more  fully  described 
by  Dr.  J.  Reid.3  A  small  part  of 
the  fibres  of  the  pyramidal  columns, 
however,  do  not  decussate,  but  pro- 
ceed downwards  on  the  same  side, 
into  the  corresponding  anterior 

Dissection  of  the  Medulla  Oblongata,  to  show  the  columns   Of  the    Spinal    Cord.— II. 
connections  of  its  several  strands  : — A,  corpus  striatum  :  mi       /->/.  •>     j- 

B,  thalamus  opticus ;  c,  D,  corpora  iuadrigemina;  a,  Tj*   Olivary  bodies    are  Composed 
commissure  connecting  them  with  the  cerebellum  ;  r,  01  fibrous  Strands,  enclosing  a  grey 
corpora  restiforinia ;  p,  p,  pons  varolii ;  st,  st,  sensory  nucleus    (Fig.    131,    O(f)    on    either 
tract;  mt,  mt,  motor  tract;  g,  olivary  tract;  p,  pyra-  g^     The  upward  continuation  of 
midal  tract;    ogr    olivary  ganglion  ;  op,  optic  nerve;  tfa      ff)rmer   divides     while   passing 
3  m,  root  of  the  thir.d  pair  (motor);  5  s,  sensory  root  Al  r    -i_     T»         *r       v    •    ± 

of  the  fifth  pair.  through  the  Pons  Varolii,  into  two 

bands,  one  of  which  proceeds  up- 
wards and  forwards  as  a  part  of  the  l  motor  tract ;  (m  t)  of  the  Crus  Cerebri, 
1  Great  diversities  will  be  found  in  the  accounts  given  of  those  connections  by  different 
authors;  some  of  which  are  attributable  to  a  variation  in  the  use  of  terras,  which  must  not 
pass  unnoticed.  By  the  majority  of  Anatomists,  the  name  of  Corpora  Restiformia  is  given 
to  the  Cerebellar  Columns :  and  this  designation,  therefore,  it  seems  advisable  to  retain. 
Some,  however,  and  amongst  them  Dr.  J.  Reid,  in  his  very  excellent  description  of  the 
Anatomy  of  the  Medulla  Oblongata  ("Edinb.  Med.  and  Surg.  Journal,"  Jan.  1841),  give 
that  name  to  the  columns  that  pass-up  from  the  posterior  division  of  the  spinal  cord  into 
the  crus  cerebri — which  are  here  called  (after  Sir  C.  Bell)  the  posterior  pyramids  ;  and 
apply  the  term  Posterior  Pyramids  to  the  Cerebellar  column.  The  truth  is  that,  as  Sir 

C.  Bell  has  justly  observed,  all  the  tracts  of  fibrous  matter  connecting  the  Brain  with  the 
Spinal  Cord,  have  a  somewhat  pyramidal  form ;  and  it  might  be  added  that  all  have  some- 
thing of  a  restiform  or  cord-like  aspect. 

3  '•  Ein  Beitrag  zur  Encephalatomie,"  Weimar,  1815. 

3  "Edinb.  Med.  and  Surg.  Journ.,"  Jan.  1841;  and  'Physiol.,  Pathol.  and  Anat.  Re- 
learches,  CHAP.  vn. 


STRUCTURE    OF    MEDULLA    0 U L 0 N G A T A . 


457 


whilst  the  other  (o)  proceeds  upwards  and  backwards  to  reach  the  Corpora  Quad- 
riiremina  (c,  D).  The  olivary  columns  are  continuous  inferiorly  with  the  anterior 
columns  of  the  Spinal  Cord;  and  afford  attachments  to  the  anterior  roots  of  the 
1st  and  2nd  cervical  nerves.  The  vesicular  nucleus,  which  is  known  as  the 
corpus  dentatum,  seems  to  be  especially  connected  with  the  origins  of  the  nerves 
concerned  in  the  regulation  of  the  movements  of  the  tongue;  thus  we  find  that 
anteriorly  a  portion  of  the  roots  of  the  Hypoglossal,  which  is  the  motor  nerve 
of  the  tongue,  issue  from  it;  whilst,  posteriorly  a  portion  of  the  roots  of  the 
G-losso-pharyngeal,  which  is  one  of  the  sensory  nerves  of  that  organ,  seem  to  ter- 
minate in  it. — in.  The  Restiform  bodies,  in  like  manner,  each  consist  of  fibrous 
strands  (F)  enclosing  a  grey  nucleus.  The  fibrous  strands  pass  upwards  into  the 
Crura  Cerebelli;  whilst  below  they  are  chiefly  continuous  with  the  posterior 
columns  of  the  Spinal  Cord,  having  also  some  connection  with  the  posterioi 
part  of  the  middle  columns.  These  Cerebellar  columns  also  communicate, 

[FIG.  132. 


w 


Transverse  section  of  the  medulla  oblongata  through  the  lower  third  of  the  olivaty  bodies, 
(from  Stilling.)  Magnified  4  diameters. 

a.  Anterior  fissure,  b.  Fissure  of  the  calamus  scriptorius.  c.  Raphe".  d.  Anterior  columns 
e.  Lateral  columns.  /.  Posterior  columns,  g.  Nucleus  of  the  hypoglossal  nerve,  containing 
large  vesicles,  h.  Nucleus  of  the  vagus  nerve,  t,  t.  Gelatinous  substance.  Jc,  k.  Roots  of  the 
ragus  nerve.  I.  Roots  of  the  hypoglossal,  or  ninth  nerve,  m.  A  thick  bundle  of  white  longitu- 
dinal fibres  connected  with  the  root  of  the  vagus,  n.  Soft  column  (Zartstrang,  Stilling),  o, 
*V edge-like  column  (Keelstrang,  Stilling),  p.  Transverse  and  arciform  fibres,  q.  Nucleus  of 
ihe  olivary  bodies,  r.  The  large  nucleus  of  the  pyramid.  «,  «,  «.  The  small  nuclei  of  the  pyra. 
toid.  u.  A  mass  of  grey  substance  near  the  nucleus  of  the  olives  (Oliven-Nebenkern').  u,  q,  r,  are 
traversed  by  numerous  fibres  passing  in  a  transverse  semicircular  direction.  »,  w.  Arciform 
fibres,  x.  Grey  fibres.] 

1  owever,  with  the  anterior  columns  of  the  Spinal  Cord  by  a  band  of '  arciform  ' 
Lbres,  whose  connections  were  first  distinctly  described  by  Mr.  Solly;1  of  these 

1  "  Philosophical  Transactions,"  1836. 


458  FUNCTIONS   OF    THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

there  is  a  superficial  set  which  unites  itself  with  the  pyramidal  columns,  and  a 
deep  set  which  comes  into  relation  with  the  olivary.  Their  grey  nucleus,  or 
1  restiform  ganglion/  appears  to  be  the  ganglionic  centre  of  the  Pneumogastric 
Serves,  and  of  a  portion  of  the  roots  of  the  Glossopharyngeal. — IV.  The  Poste- 
rior Pyramids  are  scarcely  distinguishable  externally  from  the  Restiform  bodies, 
of  which  they  were  formerly  described  as  a  constituent  part;  they  form,  however, 
the  immediate  boundaries  of  the  posterior  median  fissure  ;  and  whilst  superficially 
marked-off  from  the  Restiform  bodies  by  a  slight  groove,  are  more  completely 
separated  from  them  by  their  anatomical  relations  to  the  parts  above  and  below. 
Their  fibres  establish  a  connection  between  the  sensory  tract  (st,  si)  of  the  Crura 
Cerebri,  and  the  posterior  part  of  the  lateral  columns  of  the  Spinal  Cord,  some 
of  them  passing  also  into  its  posterior  columns.  These  fibrous  tracts  are  stated  by 
Mr.  Solly1  and  Dr.  Radclyfie  Hall2  to  decussate,  partially  at  least,  whilst  passing 
through  the  Pons  Varolii.3  The  grey  nuclei  of  the  Posterior  Pyramids,  situated 
immediately  beneath  the  '  fourth  ventricle'  (which  is  nothing  else  than  the  space 
left  by  the  divergence  of  the  Restiform  and  Posterior-Pyramidal  tracts)  are  the 
ganglionic  centres  of  the  Auditory  nerves,  or  the  proper  Auditory  ganglia  ;  and 
it  is  interesting  to  observe,  that  their  seat  precisely  corresponds  with  that  of  the 
rudimental  organ  of  hearing  in  many  Invertebrata.  (See  PRINC.  OF  COMP. 
PHYS.,  Am.  Ed.  §  711). 

490.  The  Medulla  Oblongata  is  usually  considered  as  terminating  at  the  lower 
border  of  the  Pons  Varolii ;  but  it  will  be  convenient  here  to  trace  upwards  the 
strands  by  which  it  is  connected  with  the  higher  Encephalic  centres,  as  a  clearer 
idea  of  its  anatomical  and  physiological  relations  will  thus  be  obtained. — The 
Pons  is  chiefly  composed  of  transverse  fibres,  which  constitute  the  great  com- 
missure of  the  Cerebellum  j  and  these  fibres  not  only  surround  the  longitudinal 
bands  which  connect  the  Cerebral  mass  with  the  Spinal  Cord,  but  pass  through 
them  j  so  as  in  some  degree  to  isolate  the  two  lateral  halves  from  one  another, 
and  to  form  a  complete  septum  between  the  anterior  and  posterior  portions  of 
each.  These  anterior  and  posterior  tracts  of  the  Crura  Cerebri  are  respectively 
subservient  to  the  motor  and  the  sensory  functions ;  as  is  clearly  indicated  by  the 
endowments  of  the  nerves  which  are  connected  with  each  respectively.4 — The 
Motor  tract  (Fig.  133)  is  brought  into  view,  by  simply  raising  the  superficial 
layer  of  the  Pons,  and  following  upwards  and  downwards  the  longitudinal  fibres 
which  then  present  themselves.  These  fibres  may  be  traced  upwards  into  the 
Corpora  Striata,  and  downwards  into  the  Anterior  Pyramids  and  a  portion  of  the 
Olivary  columns ;  so  that  they  connect  the  Corpora  Striata  with  the  anterior, 
and  with  the  anterior  portion  of  the  lateral,  columns  of  the  Spinal  Cord.  With 
this  tract  we  find  connected — passing  from  below  upwards — the  roots  of  the 
Spinal  Accessory,  the  Hypoglossal,  the  Facial  or  Portio  Dura  of  the  7th,  the  6th 
or  Abducens  oculi,  the  smaller  root  of  the  5th  (which  can  be  traced  to  the  part 
of  the  Olivary  column  that  passes  upwards  to  the  Corpora  Quadrigemina),  the  4th 
or  Trochlearis  (which  is  attached  to  the  same  part  of  the  tract),  and  the  3rd  or 
Oculo-motor  nerve ;  all  of  which  are  purely  motor  in  their  endowments. — The 
sensory  tract  (Fig.  134)  is  displayed,  by  opening  the  Medulla  Oblongata  on  its 
posterior  aspect;  and  then  separating  and  turning  aside  the  Restiform  columns, 
80  as  to  bring  into  view  the  posterior  pyramids.  Its  fibres  may  be  traced  upwards 
into  the  Thalami  Optici  j  whilst  they  pass  through  the  Posterior  Pyramids,  into 
the  posterior  portion  of  the  lateral  columns,  and  also  into  the  posterior  columns 

1  "The  Human  Brain,"  2nd  edit,  p.  243. 

3  "Edinb.  Med.  and  Surg.  Journ,"  July,  1847,  Plate  vn. 

8  A  decussation  of  the  Posterior  Pyramids  was  described  by  Sir  C.  Bell  as  occuring  a 
the  same  level  with  the  decussation  of  the  Anterior  Pyramids  (Fig.  134,  c) ;  there  can  be 
no  doubt,  however,  that  this  is  an  error,  which  probably  originated  in  his  having  misin- 
terpreted the  appearance  presented  by  the  posterior  aspect  of  the  anterior  decnssatiou. 
This  was  first  clearly  shown  by  Sir  C.  Bell  in  the  "  Philos.  Transact.,"  1835. 


STRUCTURE  OF  MEDULLA  OBLONGATA.       4iJU 

of  the  Spinal  Cord.     With  this  tract  are  connected  nearly  the  whole  of  the  roots 
of  the  Pneumogastric  and  Glosso-pharyngeal  nerves,  and  the  larger  or  sensory 

FIG.  133. 


Course  of  the  Motor  <rac*,  according  to  Sir  C.  Bell. — A,  A,  fibres  of  the  Hemisphere,  con- 
verging to  form  the  anterior  portion  of  the  cms  cerebri;  B,  the  same  tract,  where  passing 
the  crus  cerebri ;  c,  the  right  Pyramidal  body,  a  little  above  the  point  of  decussation ;  D,  the 
remaining  part  of  the  Pons  Varolii,  a  portion  having  been  dissected-off  to  expose  B. — 1, 
olfactory  nerve,  in  outMne ;  2,  union  of  optic  nerves ;  3,  3,  motor  oculi ;  4,  4,  patheticus ; 
5,  5,  trigeminus ;  6,  6,  its  muscular  division  ;  7,  7,  its  sensory  root ;  8,  origin,  of  sensory 
root  from  the  posterior  part  of  the  medulla  oblongata;  9,  abducens  oculi;  -10,  auditory 
nerve;  11,  facial  nerve;  12,  eighth  pair;  13,  hypoglossal;  14,  spinal  nerves;  15,  spinal 
accessory  of  right  side,  separated  from  par  vagum  and  glosso-pharyngeal. 

root  of  the  5th  pair. — The  greater  parts  of  the  Motor  tract  decussates,  where  the 
Anterior  Pyramids  become  continuous  with  the  lateral  columns  of  the  Spinal 
Cord ;  on  the  other  hand,  the  greater  part  of  the  Sensory  tract  decussates  in  its 
passage  through  the  Pons  Varolii  (Fig.  135). — The  tabular  view  (p.  461)  may 
assist  in  conveying  a  knowledge  of  this  somewhat  intricate  piece  of  Anatomy- 
which,  when  once  mastered,  will  be  found  to  be  really  simpler  than  it  appears. 


460  FUNCTIONS   OF    THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

FIG.  134. 


'VU  '*"    us*" 

Course  of  the  Sensory  tract  according  to  Sir  C.  Bell, — A,  Pons  Varolii ;  B,  B,  sensory  tract 
jeparated ;  c,  union  of  posterior  columns ;  D,  D,  posterior  roots  of  spinal  nerves  j  E,  sensory 
•00*3  of  fifth  oair. 


•oo^js  of  fifth  pair. 


[FiG.  135. 
c.ti 


The  whole  of  the  pyramidal  and  olivary  bodies  and  their  respective  tracts  have  been 
removed,  and  the  posterior  part  of  the  cord  left.  D  p.  Decussation  of  the  pyramidal  bodies. 
D  s.  Decussation  of  the  cerebral  sensory  tract,  or  posterior  third  of  the  antero-lateral  column. 
I  <fc  c.  Inter-cerebral  commissure  divided.  K.  Posterior  extremity  of  the  thalamus  nervi 
optici.  K  k.  Divided  end  of  the  same.  g.  Corpus  geniculatum  externum.  c.  Crus  cerebri. 
u  u.  Divided  end  of  the  same,  w  w.  Corpora  restiformia.  c.  Third  pair  of  nerves, 
e  a.  Corpora  albicantia.  e  «.  Sensory  root  of  the  fifth  pair.  I  n.  Locus  niger.  s  t.  Cere- 
bral sensory  tract,  p  v.  Dotted  lines  marking  the  situation  and  width  of  the  pons  Varolii, 
behind  which  the  decussation  takes  place.] 


CEPHALIC    NERVES,  —  FIFTH    PAIR,     OR    TRIGEMINUS.  461 

SPINAL  CORD,                                   MEDULLA  OBLONGATA.  BRAIN. 
Anterior  or  Motor  Division. 

f  Arciform  fibres  of  Olivary  and  Anterior  Pyramidal  columns,  Cerebellum. 

Anterior      I  Posterior  portion  of  Olivary  columns  ...............................  Corpora  Quad- 

Columns     1  Anterior  portion  of  Olivary  columns  .........................        "1  rigemina. 

[_  Non-decussating  portion  of  Anterior  Pyramidal  columns 

^Colum^ns     }  ^naBating  portion  of  Anterior  Pyramidal  columns  |  CorP<™  Siriata' 
Posterior  or  Sensory  Division. 


Decussating  portion  (?)  of  Posterior  Pyramidal  columns, 

„        •      n  i  f  Non-decussating  portion  (?)of  Posterior  Pyramidal  columns  J 

9   \Restiformcolumns  ....................................................  Cerebellum. 

491.  Nerves  of  the  Spinal  Axis.  —  With  the  Spinal  Cord  (in  its  limited  sense) 
there  are  connected  thirty-one  pairs  of  nerves  ;  each  of  which  corresponds  to  a 
vertebral  segment  of  the  body,  and  has  two  sets  of  roots,  an  anterior  and  a  pos- 
terior, differing  in  their  functional  endowments,  as  already  described  (§  472). 
The  anterior  roots  are  usually  the  smaller;  and  this  is  particularly  the  case  with 
those  of  the  cervical  nerves,  in  which  the  posterior  roots  are  of  remarkable  com- 
parative size.     In  the  first  Cervical  or  f  sub-occipital  '  pair,  the  anterior  roots 
are  sometimes  wanting  ;  but  there  is  then  a  derivation  of  fibres  from  the  Spinal 
Accessory  or  from  the  Hypoglossal,  or  from  both.     The  two  roots  of  the  ordinary 
Spinal  nerves  unite  immediately  beyond  the  ganglion,  which  is  situated  on  the 
posterior  one;    and    the   trunk   thus   formed   separates  immediately  into  two 
divisions,  —  the  anterior  and  posterior,  —  each  of  which  contains  both  afferent  and 
motor  fibres.     These  divisions,  of  which  the  anterior  is  by  far  the  larger,  proceed 
to  the  anterior  and  posterior  parts  of  the  body  respectively  ;  and  are  chiefly  dis- 
tributed to  the  skin  and  the  muscles.     The  anterior  branch  is  that  which  com- 
municates with   the   Sympathetic  nerve.  —  In  addition  to  these,  however,  the 
cranial  prolongation  of  the  Spinal  Axis  is  the  centre  of  all  the  cephalic  nerves, 
save  those  of  special  sensation,  which  terminate  in  their  respective  ganglia  ;  and 
as  these  cephalic  nerves  are  for  the  most  part  distinguished  by  the  peculiarity 
of  their  endowments,  they  require  to  be  separately  noticed 

492.  The  pair  of  nerves  commonly  designated  as  the  Fifth  of  the  Cephalic 
series,  or  as  the  Trigeminus,  is  the  one  which  more  nearly  resembles  the  ordi- 
nary Spinal  nerves,  than  does  any  other  of  those  originating  within  the  cranium. 
It  possesses  two  distinct  sets  of  roots,  of  which  one  is  much  larger  than  the  other  ; 
on  the  larger  root,  as  on  .the  posterior  and  larger  root  of  the  Spinal  nerves,  is  a 
distinct  ganglion,  known  as  the  '  Gasserian'  ;   and  the  fibres  arising  from  the 
smaller  root  do  not  blend  with  those  of  the  larger,  until  the  latter  have  passed 
through  this  ganglion.     The  trunk  of  the  nerve  separates  into  three  divisions,  — 
the  Ophthalmic,  the  Superior  Maxillary,  and  the  Inferior  Maxillary;  and  it  can 
be  easily  shown,  by  careful  dissection,  that  the  fibres  of  the  smaller  root  pass  into 
the  last  of  these  divisions  alone.     When  the  distribution  of  this  nerve  is  carefully 
examined,  it  is  found  that  the^rs^  and  second  divisions  of  it  proceed  almost  entirely 
to  the  Skin  and  Mucous  surfaces,  only  a  very  small  proportion  of  their  fibres  being 
lost  in  the  muscles  ;  whilst  of  the  branches  of  the  third  division,  a  large  number 
are  distinctly  Muscular.     Hence  analogy,  and  the  facts  supplied  by  anatomical 
research,  would  lead  to  the  conclusion,  that  the  first  two  divisions  are  nerves  of 
sensation  only,  and  that  the  third  division  combines  sensory  and  motor  endow- 
ments.    Such  an  inference  is  fully  borne-out  by  experiment.     When  the  whole 
trunk  is  divided  within  the  cranium  by  the  penetration  of  a  sharp  instrument 
(which  Magendie,  by  frequent  practice,  has  been  able  to  accomplish),  evident 
signs  of  acute  pain  are  given.     After  the  incision  has  been  made  through  the 
skin,  the  animal  remains  quiet  until  the  nerve  is  touched  ;  and  when  it  is  pressed 
or  divided,  doleful  cries  are  uttered,  which  continue  for  some  time,  showing  the 
painful  effect  of  the  irritated  state  of  the  cut  extremity.     The  common  sensibility 


462  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

of  all  the  parts  supplied  by  this  nerve  is  entirely  destroyed  on  the  affected  side. 
The  jaw  does  not  hang  loosely,  because  it  is  partly  kept-up  by  the  muscles  of  the 
other  side ;  but  it  falls  in  a  slight  degree ;  and  its  movements  are  seen,  when 
carefully  observed,  to  be  somewhat  oblique.  If  the  trunk  be  divided  on  each  side, 
the  whole  head  is  deprived  of  sensibility ;  and  the  animal  carries  it  in  a  curious 
vacillating  manner,  as  if  it  were  a  foreign  body. — If  the  anterior  or  Ophthalmic 
branch  only  be  divided,  all  the  parts  supplied  by  it  are  found  to  have  lost  their 
sensibility,  but  their  motions  are  unimpaired;  and  all  experiments  and  patho- 
logical observations  concur  in  attributing  to  it  sensory  endowments  only.  The 
only  apparent  exception  is  in  the  case  of  the  naso-ciliary  branch,  since  there  is 
good  reason  to  believe  that  the  long  root  of  the  ciliary  ganglion  and  the  long 
ciliary  nerves  possess  motor  powers ;  but  these  appear  to  be  derived  from  the 
Sympathetic  or  from  the  3rd  pair.  When  the  whole  nerve,  or  its  anterior 
branch,  is  divided  in  the  rabbit,  the  pupil  is  exceedingly  contracted,  and  remains 
immovable ;  but  in  dogs  and  pigeons  it  is  dilated.  The  pupil  of  the  other  eye 
is  scarcely  affected ;  or,  if  its  dimensions  be  changed,  it  soon  returns  to  its  natural 
state.  The  eyeball,  however,  speedily  becomes  inflamed ;  and  the  inflammation 
usually  runs-on  to  suppuration  and  complete  disorganization.  The  commence- 
ment of  these  changes  may  be  commonly  noticed  within  twenty-four  hours  after 
the  operation  ;  and  they  appear  to  be  due  to  the  want  of  the  protective  secretion, 
which  is  necessary  to  keep  the  mucous  surface  of  the  eye  in  its  healthy  condition, 
and  which  is  not  formed  when  the  sensibility  of  that  surface  is  destroyed. — The 
Superior  Maxillary  branch,  considered  in  itself,  is  equally  destitute  of  motor 
endowments  with  the  ophthalmic;  but  its  connection  with  other  nerves,  through 
the  spheno-palatine  ganglion  and  its  anastomosing  twigs,  may  introduce  a  few 
motor  fibres  into  it. — The  Inferior  Maxillary  branch  is  the  only  one  which 
possesses  motor  as  well  as  sensory  endowments  from  its  origin ;  but  its  different 
subdivisions  possess  these  endowments  in  var}ing  proportions,  some  being  almost 
exclusively  motor,  and  others  as  completely  of  a  sensory  character.  The  latter 
is  probably  the  nature  of  the  Lingual  branch ;  and  there  seems  good  reason  to 
believe,  as  will  hereafter  be  shown  (§  495),  that  this  ministers  not  only  to  the 
tactile  sensibility  of  the  tongue,  but  to  the  sense  of  Taste.  The  muscles  put  in 
action  by  this  division,  are  solely  those  concerned  in  the  masticatory  movements. — 
The  5th  pair  is  connected,  in  different  parts  of  its  course,  with  a  number  of  small 
ganglia  belonging  to  the  Sympathetic  system.  One  of  the  most  interesting  of 
these  ganglia  is  the  Ophthalmic  or  Ciliary  (Fig.  136 a),  which  is  the  centre 
whence  the  eyeball  derives  its  supply  of  nerves,  sensoryj  motor,  and  sympathetic. 
This  ganglion  derives  its  sensory  fibres  by  its  '  long  root'  from  the  nasal  branch 
of  the  Ophthalmic  divi-ion  of  the  5th  pair;  its  motor  fibres,  by  the  ' short  root* 
from  the  3rd  pair;  whiUt  by  another  small  root,  it  is  connected  with  the  cavern- 
ous plexus  of  the  Sympathetic  system; — thus  presenting  a  sort  of  miniature 
representation  of  the  entire  series  of  Sympathetic  ganglia,  and  of  their  con- 
nections with  the  Cerebro-spinal  system.1 

1  The  functions  of  this  ganglion  have  been  made  the  subject  of  particular  investigation 
by  Dr.  C.  Radclyffe  Hall  ("Edinb.  Med.  and  Surg.  Journal,"  1846-48),  whose  most 
important  results  are  as  follows : — 

1.  The  size  of  the  ciliary  ganglion  is  always  in  direct  proportion  to  the  activity  of  the 
iris,  which  in  turn  always  bears  a  direct  relation  to  the  strength  and  acuteness  of  vision, 
and  to  the  nocturnal  habits  of  the  animal,  and  implies  a  proportionate  development  of  the 
internal  vascular  apparatus  of  the  eye. 

2.  The  ganglion  is  always  more  intimately  connected  with  the  3rd  pair,  than  with  any 
other ;  the  size  of  the  short  root  being  always  in  direct  relation  to  that  of  the  ganglion, 
and  the  ganglion  being  sometimes  a  mere  swelling  on  the  trunk  of  the  nerve. 

3.  The  fibres  derived  from  the  5th  pair  do  not  terminate  in  the  ganglion,  but  pass  onwarda 
through  it  to  the  ciliary  plexus. 

4.  In  the  Rabbit,  the  iris  receives  fibres  from  the  6th  pair  which  do  not  pass  through 
Ihe  ganglion ;  and  it  is  through  this  that  the  contraction  of  the  pupil  is  produced  in  that 
auimal  by  irritation  of  the  fith  pair,  which  will  not  produce  any  effect  upon  the  pupil  of 


CEPHALIC   NERVES. — THIRD,    FOURTH   AND    SIXTH.  463 

493.  The  Third,  Fourth,  and  Sixth  pairs,  together  make-up  the  apparatus  of 
motor  nerves,  by  which  the  muscles  of  the  Orbit  are  called  into  action.  The 
3rd  pair  supplies  the  greater  number  of  the  muscles ;  the  4th  being  confined  to 
the  Superior  Oblique,  and  the  6th  to  the  External  Rectus.  Of  these  nerves,  the 


FIG.  136. 


The  Nerves  of  the  Orbit  seen  from  the  outer  side : — 1.  Section  of  the  frontal  bone ;  imme- 
diately behind  the  numeral  is  the  frontal  sinus,  and,  in  front,  the  integument.  2.  The  superior 
maxillary  bone  ;  the  section  in  front  of  the  numeral  exhibits  the  maxillary  sinus.  3.  Part  of 
the  sphenoid  bone.  4.  The  levator  palpebrae  and  superior  rectus  muscles.  5.  The  superior 
oblique  muscle,  6.  The  inferior  oblique  muscle.  7.  The  ocular  half  of  the  external  rectus 
muscle  drawn  forwards.  8.  The  orbital  half  of  the  external  rectus  muscle  turned  downwards. 
On  this  muscle  the  sixth  nerve  is  seen  dividing  into  branches.  9.  The  inferior  rectus  muscle. 
10.  The  optic  nerve.  11.  The  internal  carotid  artery  emerging  from  the  cavernous  sinus. 
12.  The  ophthalmic  artery.  13.  The  third  nerve.  14.  The  branch  of  the  third  nerve  to  the 
inferior  oblique  muscle.  Between  this  and  the  sixth  nerve  (8)  is  seen  the  branch  which  sup- 
plies the  inferior  rectus ;  its  branch  to  the  ophthalmic  ganglion  is  seen  proceeding  from  the 
upper  side  of  the  trunk  of  the  nerve,  at  the  bottom  of  the  orbit.  15.  The  fourth  nerve.  16. 
The  trunk  of  the  fifth  nerve.  17.  The  Gasserian  ganglion.  18.  The  ophthalmic  nerve.  19. 
The  superior  maxillary  nerve.  20.  The  inferior  maxillary  nerve.  21.  The  frontal  nerve. 
22.  Its  division  into  branches  to  supply  the  integument  of  the  forehead.  23.  The  lachrymal 
nerve.  24.  The  nasal  nerve ;  the  small  nerve  seen  in  the  bifurcation  of  the  nasal  and  frontal 
nerve,  is  one  of  the  branches  of  the  upper  division  of  the  third  nerve.  25.  The  nasal  nerve 
passing  over  the  internal  rectus  muscle  to  the  anterior  ethmoidal  foramen.  26.  The  infra- 
trochlear  nerve.  27.  A  long  ciliary  branch  of  the  nasal ;  another  long  ciliary  branch  is  seen 
proceeding  from  the  lower  aspect  of  the  nerve.  28.  The  long  root  of  the  ophthalmic  gan- 
glion, proceeding  from  the  nasal  nerve,  and  receiving  the  sympathetic  root  which  joins  it  at 
an  acute  angle.  29.  The  ophthalmic  ganglion,  giving  off  from  its  fore-part  the  short  ciliary 
nerves.  30.  The  globe  of  the  eye. 

3rd  pair  is  the  only  one  which  exhibits  any  appearance  of  sensibility,  when  its 
trunk  is  irritated  ;  but  this  sensibility  is  not  nearly  so  great  as  that  of  the  5th 

the  Dog,  Cat,  or  Pigeon,  so  long  as  it  does  not  affect  the  brain  to  the  extent  of  producing 
vertigo,  nor  affect  the  visual  sense  in  any  other  way. 

5.  Irritation  of  the  5th  nerve  does  not  in  any  animal  affect  the  action  of  the  iris,  after 
the  division  of  the  cerebral  connections  of  all  the  other  ocular  nerves :  so  that  its  influence 
over  the  movements  of  the  iris  must  be  reflected  through  the  encephalic  centres,  not  through 
the  ophthalmic  ganglion. 

6.  The  function  of  the  ganglionic  centre  itself,  as  a  part  of  the  Sympathetic  system, 
seems  to  be  to  bring  the  '  organic  actions'  of  the  eyeball,  especially  its  supply  of  blood, 
into  harmony  with  its  functional  activity ;    this  harmony  being  produced  by  the  passage 
of  the  cerebro-spinal  nerves  through  the  ganglion,  which  excites  the  synergetic  action  of  its 
own  vesicles  and  nerve-fibres. 


464  FUNCTIONS   OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

pair ;  and  as  there  is  no  reason  to  believe  that  it  is  really  possessed  by  the  3rd 
in  virtue  of  its  direct  connection  with  the  nervous  centres,  it  is  probably  im- 
parted by  the  anastomosis  of  that  nerve  with  the  5th,  —  some  filaments  of  which 
may  pass  backwards  as  well  as  forwards,  so  as  to  confer  sensibility  on  the  trunk 
of  the  3rd,  above  as  well  as  beyond  their  point  of  entrance. — The  peculiar  mode 
in  which  those  motor  nerves  ordinarily  excite  the  muscles  to  action,  under  the 
guidance  of  the  visual  sense,  will  be  considered  in  the  next  Section  (§§  542, 
546).  Although  commonly  ranked  as  cephalic  nerves,  they  have  no  direct  con- 
nection with  the  Cerebrum ;  their  real  origin  being  from  the  upper  part  of  the 
Spinal  Axis  (§  490).  The  roots  of  the  3rd  pair  may  be  traced  into  direct  con- 
nection with  the  Corpora  Quadrigemina ;  a  fact  of  considerable  physiological  im- 
portance, as  will  hereafter  appear.  —  The  chief  actions  of  a  purely -reflex  nature 
to  which  this  group  of  nerves  ordinarily  ministers,  are  the  government  of  the 
diameter  of  the  pupil,  which  is  accomplished  through  the  Third  pair ;  and  the 
rolling  of  the  eyeball  beneath  the  upper  lid  during  sleep,  as  well  as  in  the  efforts 
of  sneezing,  coughing,  &c.  But  irregular  movements  of  the  eyeballs,  which 
must  be  referred  to  the  same  group,  are  continually  seen  to  accompany  various 
abnormal  forms  of  convulsive  action. 

494.  The  Portia  Dura  of  the  Seventh  pair,  or  Facial  nerve,  has  been  usually 
considered,  subsequently  to  the  researches  of  Sir  C.  Bell,  as  a  nerve  of  motion 

FIG.  137. 


The  distribution  of  the  Facial  Nerve,  and  the  branches  of  the  Cervical  plexus.  —  1.  The 
facial  nerve,  escaping  from  the  stylo-mastoid  foramen,  and  crossing  the  ramus  of  the  lower 
jaw;  the  parotid  gland  has  been  removed  in  order  to  show  the  nerve  more  distinctly.  2.  The 
posterior  auricular  branch ;  the  digastric  and  stylo-mastoid  filaments  are  seen  near  the 
origin  of  this  branch.  3.  Temporal  branches,  communicating  with  (4)  the  branches  of  the 
frontal  nerve.  5.  Facial  branches,  communicating  with  (6)  the  infra-orbital  nerve.  7. 
Facial  branches,  communicating  with  (8)  the  mental  nerve.  9.  Cervico-facial  branches,  com- 
municating with  (10)  the  superficialis  colli  nerve,  and  forming  a  plexus  (11)  over  the  sub- 
maxillary  gland.  The  distribution  of  the  branches  of  the  facial  in  a  radiated  direction  over 
the  side  of  the  face,  constitutes  the  pes  anserinus.  12.  The  auricularis  magnus  nerve,  one  of 
the  ascending  branches  of  the  cervical  plexus.  13.  The  occipitalis  minor,  ascending  along 
the  posterior  border  of  the  sterno-mastoid  muscle.  14.  The  superficial  and  deep  descending 
branches  of  the  cervical  plexus.  15.  The  spinal  accessory  nerve,  giving-off  a  branch  to  the 
external  surface  of  the  trapezius  muscle.  16.  The  occipitalis  major  nerve,  the  posterior 
branch  of  the  second  cervical  nerve. 


CEPHALIC  NERVES. — GLOSSO-PHARYNGEAL  NEKVE.       465 

only;  but  some  physiologists  have  maintained,  that  it  both  possesses  sensory  en- 
dowments, and  arises  by  a  double  root.  According  to  Valentin,  however,  who 
has  experimented  on  the  roots  exposed  within  the  cranium,  it  possesses  no  sen- 
eory  endowments  at  its  origin  ;  since,  when  these  roots  were  touched,  the  animals 
gave  no  signs  of  pain,  though  violent  muscular  movements  were  excited  in  the 
face.  Subsequently  to  its  first  entrance  into  the  canal  by  which  it  emerges,  how- 
ever, it  anastomoses  with  other  nerves ;  and  thus  sensory  fibres  are  introduced 
into  it  from  many  different  sources  (anteriorly  from  the  5th  pair,  and  posteriorly 
from  the  cervical  nerves),  which  cause  irritation  of  several  of  its  branches  to 
produce  pain.  The  number  and  situation  of  the  anastomoses  vary  much  in  dif- 
ferent animals,  so  that  it  is  impossible  to  make  any  very  comprehensive  statement 
in  regard  to  them. — Experimental  researches  leave  no  doubt  that  the  Portio 
Dura  is  the  general  motor  nerve  of  the  face;  ministering  to  the  influence  of 
Volition  and  of  Emotion,  and  also  being  the  channel  of  the  reflex  movements 
concerned  in  respiration,  as  of  other  automatic  actions  of  the  muscles;  but  not 
being  in  the  least  concerned  in  the  act  of  mastication. 

495.  Although  the  functions  of  the  Glosso-Pharynyeal  nerve  have  been  hereto- 
fore alluded-to  in  part,  several  questions  still  remain  to  be  discussed  in  regard  to 
them.  Reasons  have  been  given  for  the  belief,  that  it  is  chiefly  an  afferent  nerve 
— scarcely  having  any  direct  power  of  exciting  muscular  contraction,  but  convey- 
ing impressions  to  the  Medulla  Oblongata,  which  produce  reflex  movements  of 
the  motor  nerves  concerned  in  deglutition  (§  81).  This  view  of  its  function  was 
deduced  by  Dr.  J.  Reid  from  minute  anatomical  investigation,  and  from  a  large 
number  of  experiments.  Some  experimenters  assert,  that  they  have  succeeded 
in  exciting  direct  muscular  actions  through  its  trunk  ;  but  these  actions  seem  to 
be  limited  to  the  stylo-pharyngei  and  palato-glossi  muscles. — Much  controversy 
has  taken  place  on  the  question,  whether  this  nerve  is  to  be  regarded  as  minister- 
ing partly  or  exclusively,  to  the  sense  of  Taste  ;  and  many  high  authorities  have 
ranged  themselves  on  each  side.  The  question  involves  that  of  the  function  of 
the  Lingual  branch  of  the  5th  pair;  and  it  is  partly  to  be  decided  by  the  anato- 
mical relations  of  the  two  nerves  respectively.  The  Glosso-pharyngeal  is  princi- 
pally distributed  on  the  mucous  surface  of  the  fauces,  and  on  the  back  of  the 
tongue ;  but  according  to  Valentin,  it  sends  a  branch  forwards  on  either  side, 
somewhat  beneath  the  lateral  margin,  which  supplies  the  edges  and  inferior  sur- 
face of  the  tip  of  the  tongue,  and  inosculates  with  the  Lingual  branch  of  the  5th. 
On  the  other  hand,  the  upper  surface  of  the  front  of  the  tongue  is  supplied  by 
this  Lingual  branch.  The  experiments  of  Dr.  Alcock,  whose  conclusions  are 
borne  out  by  Dr.  J.  Reid,  decidedly  support  the  conclusion,  that  the  gustative 
sensibility  of  this  part  of  the  tongue  is  chiefly  due  to  the  latter  nerve,  being  evi- 
dently impaired  by  division  of  it.  On  the  other  hand,  it  is  equally  certain,  that 
the  sense  of  taste  is  not  destroyed  by  section  of  the  Lingual  nerve  on  each  side  ; 
and  it  seems  also  well  ascertained,  that  it  is  impaired  by  section  of  the  Glosso- 
pharyngeal  nerve. — The  pathological  evidence  bearing  upon  this  point  appears 
somewhat  contradictory.  Numerous  cases  have  been  recorded,1  in  which  both 
common  and  gustative  sensation  were  destroyed  in  the  parts  of  the  tongue  supplied 
by  the  5th  pair,  when  that  nerve  was  paralysed  ;  in  some  of  these,  the  loss  of 
the  sense  of  taste  appeared  to  extend  itself  to  the  base  of  the  tongue,  but  then 
there  was  evidence  that  the  Glosso-pharyngeal  was  involved  in  the  paralysis.  On 
the  other  hand,  cases  of  paralysis  of  the  5th  pair  are  related  by  Mr.  Noble  and 
by  Vogt,2  in  which  common  sensation  was  lost,  whilst  the  sense  of  taste  remained 
in  the  same  parts ;  and  Mr.  Noble  relates  another  case,3  in  which  there  was  losg 

*  See  especially  the  cases  recorded  by  Romberg,  in  "  Miiller's  Archiv.,"  1838,  heft  iii. ; 
ToJd  and  Bowman,  in  "  Physiological  Anatomy,"  p.  386,  Am.  Ed.;  and  Dixon,  in  "Med. 
Chir.  Trans.,"  vol.  xxviii. 

-     a  «  Medical  Gazette,"  Oct.  25,  1834  ;  and  "  Muller's  Archiv.,"  1840,  p.  72. 

•  "Medical  Gazette,"  Nov.  21,  1835. 

30 


466  FUNCTIONS    OF  THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

of  taste  without  impairment  of  common  sensation.  The  cases  of  Mr.  Noble  and 
Vogt  would  seem  to  indicate  that  the  5th  pair  does  not  minister  to  the  sense  of 
Taste ;  but,  as  Dr.  J.  Reid  has  justly  observed,  we  have  no  evidence  that  all  the 
filaments  of  the  fifth  Pair  sent  to  the  tongue  were  affected ;  and  there  is  believed 
to  be  no  case  on  record;  in  which  the  whole  of  the  5th  pair,  or,  of  its  3rd  branch, 
was  found  to  be  diseased  after  death,  and  in  which  during  life  the  sense  of  Taste 
had  been  retained  in  the  anterior  and  middle  parts  of  the  tongue.  Hence  these 
cases  only  serve  to  indicate  what  is  probable  on  other  grounds,  viz.,  that  the  fila 
ments  which  convey  gustative  impressions  are  not  the  same  with  those  that  min- 
ister to  common  sensation.  On  the  whole,  then,  it  seems  to  be  proved  by  anato- 
mical and  experimental  evidence,  that  both  the  Glosso-pharyngeal  and  the  Fifth 
pair  minister  alike  to  the  tactile  and  to  the  gustative  sense ;  and  there  is  nothing 
in  the  pathological  facts  just  noticed,  that  militates  against  this  conclusion.  There 
seems  good  reason  to  believe  the  Glosso-pharyngeal  to  be  exclusively  the  nerve, 
through  which  the  impressions  made  by  disagreeable  substances  taken  into  the 
mouth  are  propagated  to  the  Medulla  Oblongata,  so  as  io  produce  nausea  and  to 
excite  efforts  to  vomit. 

496.  The  functions  of  the  Pneumogastric  nerve  at  its  roots  have  been  made 
the  subject  of  particular  examination  by  various  experimenters;  some  of  whom 
(for  instance,  Valentin,  Longet,  and  Morganti)  have  concluded  that  it  there  pos- 
sesses no  motor  power,  but  is  entirely  a  sensory  or  rather  an  afferent  nerve.  Ac- 
cording to  these,  if  the  roots  be  carefully  separated  from  those  of  the  Glosso- 
Pharyngeal,  and  (which  is  a  matter  of  some  difficulty)  from  those  of  the  Spinal 
Accessory  nerve,  and  be  then  irritated,  no  movements  of  the?  organs  supplied  by 
its  trunk  can  be  observed;  whilst,  if  the  roots  be  irritated  when  in  connection 
with  the  nervous  centres,  muscular  contractions,  evidently  of  a  reflex  character, 
result  from  the  irritation ;  and  strong  evidences  of  their  sensibility  are  also  given. 
It  has  been  further  asserted  that,  when  the  roots  of  the  spinal  Accessory  nerve 
ire  irritated,  no  indications  of  sensation  are  given ;  but  that  the  muscular  parts 
supplied  by  the  Pneumogastric,  as  well  as  by  its  own  trunk,  are  made  to  con- 
tract, even  when  the  roots  are  separated  from  the  nervous  centres ;  so  that  these 
roots  must  be  regarded  as  the  channel  of  the  motor  influence,  transmitted  to 
them  from  the  Medulla  Oblongata.  Where  the  Pneumogastric  swells  into 
the  jugular  ganglion,  an  interchange  of  fibres  takes  place  between  it  and  the  Spi- 
nal Accessory;  and  it  seems  clear  that  the  pharyngeal  branches,  which  are 
among  the  most  decidedly  motor  of  all  those  given-off  from  the  Pneumogastric, 
may  in  great  part  be  traced  backwards  into  the  Spinal  Accessory. — But,  on  the 
other  hand,  an  equally  numerous  and  trustworthy  set  of  experimenters  (among 
whom  may  be  mentioned  J.  Reid,  Miiller,  Volkmann,  Stilling,  Wagner,  and 
Bernard)  are  opposed  to  this  opinion;  maintaining  that  the  Pneumogastric  has 
motor  roots  of  its  own ;  and  affirming  that  irritation  of  the  roots  of  the  Spinal 
Accessory  produces  little  or  no  effect  on  the  muscles  supplied  by  the  trunk  of  the 
Par  Vagum  — The  fact  appears  to  be  that  the  roots  of  these  two  nerves  are  so 
commingled,  that  it  is  difficult  to  say  what  belong  exclusively  to  each.  Some  of 
the  fibres  usually  considered  to  belong  to  the  Spinal  Accessory,  are  occasionally 
seen  to  connect  themselves  with  the  roots  of  the  Pneumogastric,  even  before  the 
ganglion  is  found  upon  it.  And  it  seems  most  probable,  that  while  the  roots  of 
the  Spinal  Accessory  are  entirely  motor,  those  of  the  Pneumogastric  are  chiefly 
afferent;  that  they  inosculate  with  each  other,  in  a  degree  which  may  vary  in 
different  species,  and  even  in  different  individuals ;  and  that  the  Pneumogastric 
may  thus  derive  additional  motor  fibres  from  the  Spinal  Accessory,  while  it  sup- 
plies that  nerve  with  afferent  fibres.  Further,  it  appears  probable,  from  the 
researches  of  M.  Cl.  Bernard,  to  be  presently  noticed  (§  498),  tha-t  the  motor 
fibres  properly  belonging  to  the  Pneumogastric  are  adequate  to  the  regulation 
of  those  movements  of  the  larynx  and  other  portions  of  the  air-passages,  which 
are  concerned  in  the  passive  act  of  Respiration. 


CEPHALIC   NERVES. — PNEUMOGASTRIC   NERVE. 
138-  [Fio.  139. 


467 


Origin  and  distribution  of  the  Eighth  Pair  of 
nerves  —  1,  3,  4.  The  Medulla  Oblongata.  1. 
The  Corpus  Pyramidale  of  one  side.  3.  The 
Corpus  Olivare.  4.  The  Corpus  Restiforme.  2. 
The  Pons  Varolii.  b.  The  Facial  nerve.  6.  The 
origin  of  the  Glosso-pharyngeal  nerve.  7.  The 
ganglion  of  Andersch.  8.  The  trunk  of  the 
nerve.  9.  The  Spinal  Accessory  nerve.  10.  The 
ganglion  of  the  Pneumoyastric  nerve.  11.  Its 
plexiforra  ganglion.  12.  Its  trunk.  13.  Its 
pharyngeal  branch  forming  the  pharyngeal 
plexus  (14)  assisted  by  a  branch  from  the 
glosso-pharyngeal  (8)  and  one  from  the  superior 
luryngeal  nerve  (15).  16.  Cardiac  branches. 
17.  Recurrent  laryngeal  branch.  18.  Anterior 
pulmonary  branches.  19.  Posterior  pulmonary 
branches.  20.  (Esophageal  plexus.  21.  Gas- 
tric branches.  22.  Origin  of  the  Spinal  Acces- 
bory  nerve.  23.  Its  branches  distributed  to  the 
FtorTio-mnstoid  muscle.  24.  Its  branches  to  the 
trapezius  muscle. 


A  view  of  the  distribution  of  the  Glosso-Pha- 
ryngeal,  Pneumogastric  and  Spinal  Accessory 
nerves,  or  the  Eighth  pair :  1,  the  inferior  maxil- 
lary nerve  ;  2,  the  gustatory  nerve ;  3,  the  chorda 
tympani ;  4,  the  auricular  nerve ;  5,  its  commu- 
nication with  the  portio  dura;  6,  the  facial 
nerve  coming  out  of  the  stylo-mastoid  foramen  • 
7,  the  glosso-pharyngeal  nerve  j  8,  branches  to 
the  stylo-pharyngeus  muscle;  9.  the  pharyngeal 
branch  of  the  pneumogastic  nerve  descending 
to  form  the  pharyngeal  plexus  ;  10,  branches  of 
the  glosso-pharyngeal  to  the  pharyngeal  plexus; 
11,  the  pneumogastric  nerve ;  12,  the  pharyn- 
geal plexus  ;  13,  the  superior  laryngeal  branch; 
14,  branches  to  the  pharyngeal  plexus;  15,  15, 
communication  of  the  superior  and  inferior 
laryngeal  nerve;  16,  cardiac  branches  ;  17,  car- 
diac branches  from  the  right  pneumogastrio 
nerve  ;  18,  the  left  cardiac  ganglion  andplexu? ; 

19,  the  recurrent  or  inferior  laryngeal  nerve; 

20,  branches  sent  from  the  curve  of  the  recur- 
rent nerve  to  the   pulmonary  plexus;  21,  the 
anterior  pulmonary  plexus;  22,  22,  the  resopha- 
geal  plexus.] 


468  FUNCTIONS    OF    THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

497.  There  can  be  no  doubt  that  the  trunk  of  the  Pneumogastric  is  to  be  con- 
sidered  as  a  nerve  of  double  endowments;  although  it  is  certain  that  these 
endowments  are  very  differently  distributed  amongst  its  branches.     That  the 
nerve  is  capable  of  conveying  those  impressions,  which  become  sensations  when 
communicated  to  the  sensorium,  is  experimentally  proved  by  the  fact,  that,  when 
its  trunk  is  pinched,  the  animal  gives  signs  of  acute  pain  :  but  it  is  also  evident 
from  the  painful  consciousness  we  occasionally  have,  of  an  abnormal  condition  of 
the  organs  which  it  supplies.     Thus,  the  suspension  of  the  respiratory  move- 
ments gives  rise  to  a  feeling  of  the  greatest  uneasiness,  which  must  be  excited  by 
impressions  conveyed  through  this  nerve  from  the  lungs;  and  an  inflamed  state 
of  the  walls  of  the  air-passages  causes  the  contact  of  cold  and  dry  air  to  produce 
distressing  pain  and  irritation :  yet  of  the  ordinary  impressions  conveyed  from 
these  organs,  which  are  concerned  in  producing  the  respiratory  movements,  and 
in  regulating  the  actions  of  the  glottis,  we  are  not  conscious.     The  same  may  be 
said  of  the  portion  of  the  nerve  distributed  upon  the  alimentary  tube :  for  the 
pharyngeal   branches  are  almost  exclusively  motor,  the  afferent  function  being 
performed  by  the  Glosso-pharyngeal;  whilst  the  cesophageal  and  gastric  are  both 
afferent  and  motor,  conveying  impressions  which  excite  reflex  movements  in  the 
muscles  of  those  parts,  but  which  do  not  become  sensations  except  under  extra- 
ordinary circumstances.     The  participation  of  this  nerve  in  the  operations  of 
Deglutition,  Digestion,  Circulation,  and  Respiration,  and  the  effects  of  injury  to 
its  trunk  or  branches,  have  already  been  considered  in   the  account  of  those 
functions. 

498.  In  regard  to  the  functions  of  the  Spinal  Accessory  nerve,  also,  there  has 
been  great  difference  of  opinion ;  the  peculiarity  of  its  origin  and  course  having 
led  to  the  belief,  that  some  very  special  purpose  is  answered  by  it.     The  roots  of 
this  nerve  arise  from  the  side  of  the  Spinal  Cord,  as  low  down  as  the  5th  or  6th 
cervical  nerve;  and  the  trunk  formed  by  them  ascends  into  the  cranium  between 
the  anterior  and  posterior  roots  of  the  spinal  nerves.    From  the  recent  researches 
of  Mr.  J.  L.  Clark,1  it  appears  that  these  roots  may  be  traced  into  a  special  tract 
of  vesicular  matter,  which  descends  as  far  as  the  lumbar  enlargement.     The  pre- 
dominance of  motor  fibres  in  its  roots,  its  inosculation  with  the  Pneumogastric, 
and  its  probable  reception  of  sensory  fibres  from  the  latter,  whilst  imparting  to 
it  motor  filaments,  have  been  already  referred-to  (§  496).     As  its  trunk  passes 
through  the  foramen  lacerum,  it  divides  into  two  branches ;  of  which  the  internal, 
after  giving-off  some  filaments  that  assist  in  forming  the  pharyngeal  branch  of 
the  Pneumogastric,  becomes  incorporated  with  the  trunk  of  that  nerve ;  whilst 
the  external  proceeds  outwards,  and  is  finally  distributed  to  the  sterno-cleido- 
mastoideus  and  trapezius  muscles,  some  of  its  filaments  inosculating  with  those 
of  the  cervical  plexus.     When   the  external  branch  is  irritated,  before  it  per- 
forates the  sterno-mastoid  muscle,  vigorous  convulsive  movements  of  that  muscle 
and  of  the  trapezius  are  produced ;  and  the  animal  does  not  give  any  signs  of 
pain,  unless  the  nerve  be  firmly  compressed  between  the  forceps,  or  be  included 
in  a  tight  ligature.     Hence  it  may  be  inferred,  that  the  functions  of  this  nerve 
are  chiefly  motor,  and  that  its  sensory  filaments  are  few  in  number.     Further, 
when  the  nerve  has  been  cut-across,  or  firmly  tied,  irritation  of  the  lower  end  is 
attended  by  the  same  convulsive  movements  of  the  muscles :  whilst  irritation  of 
the  upper  end  in  connection  with  the  spinal  cord,  is  unattended  with  any  mus- 
cular movement.     Hence  it  is  clear  that  the  motions  occasioned  by  irritating  it 
are  of  a  direct,  not  of  a  reflex  character.     The  same  muscular  movements  are 
observed  on  irritating  the  nerve  in  the  recently-killed  animal,  as  during  life. — 
According  to  Sir  C.  Bell,  the  Spinal  Accessory  is  a  purely  Respiratory  nerve, 
whose  office  it  is  to  excite  the  involuntary  or  automatic  movements  of  the  mus- 
cles it  supplies,  which  share  in  the  act  of  respiration  •  and  he  states  that  the 
division  of  it  paralyses,  as  muscles  of  respiration,  the  muscles  to  which  it  is  dig- 

ributed;    though   they  still  perform  the  voluntary  movements,   through   the 
1  "Philosophical  Transactions,"  1851,  p.  613. 


CEPHALIC  NERVES.  —  HYPO-GLOSSAL  NERVE.    469 

medium  of  the  spinal  nerves.  Both  Valentin  and  Dr.  J.  Reid,  however,  posi- 
tively deny  that  this  is  the  case;  and  Dr.  Reid's  method  of  experimenting  was 
well  adapted  to  test  the  truth  of  the  assertion.1  The  functions  of  this  nerve  have 
been  made  the  subject  of  special  examination  by  M.  Cl.  Bernard,2  who  has 
arrived  at  the  conclusion  that  the  Spinal  Accessory  is  a  purely  motor  nerve, 
whose  action  is  not  essential  to  the  ordinary  movements  of  respiration,  these 
being  provided-for  by  the  Pneumogastric  and  ordinary  Spinal  nerves ;  but  that 
its  special  function  is  to  bring  the  respiratory  movements  into  accordance  with 
the  requirements  of  Animal  life,  adapting  the  actions  of  the  muscles  of  the 
larynx  and  thorax  to  the  production  of  voice,  or  to  general  muscular  effort.  The 
internal  branch,  which  is  specially  distributed,  with  the  fibres  of  the  Pneumo- 
gastric, to  the  pharynx  and  larynx,  is  peculiarly  subservient  to  the  former  of 
these  purposes  ;  and  the  external  to  the  latter.  This  conclusion  is  sufficiently  in 
accordance  with  the  results  obtained  by  other  experimenters,  to  be  received  as  a 
probable  explanation  of  the  facts  which  have  been  observed  by  them. 

499.  The  Hypoglossal  nerve,  or  Motor  Linguae,  is  the  only  one  which,  in  the 
regular  order,  now  remains  to  be  considered  (Fig.  140).     That  the  distribution 

[Fig.  140. 


The  course  and  distribution  of  the  Hypoglossal  or  Ninth  pair  of  nerves;  the  deep-seated 
nerves  of  the  neck  are  also  seen  :  1,  the  hypoglossal  nerve  ;  2,  branches  communicating  with 
the  gustatory  nerve ;  3,  a  branch  to  the  origin  of  the  hyoid  muscles ;  4,  the  descendens  noni 
nerve  ;  5,  the  loop  formed  with  the  branch  from  the  cervical  nerves  ;  6,  muscular  branches  to 
the  depressor  muscles  of  the  larynx ;  7,  a  filament  from  the  second  cervical  nerve,  and  8,  a 
filament  from  the  third  cervical,  uniting  to  form  the  communicating  branch  with  the  loop  from 
the  descendens  noni ;  9,  the  auricular  nerve  10,  the  inferior  dental  nerve ;  11,  its  mylo- 
hyoidean  branch  ;  12,  the  gustatory  nerve ;  13,  the  chorda  tympani  passing  to  the  gustatory 
nerve  ;  14,  the  chorda  tympani  leaving  the  gustatory  nerve  to  join  the  submaxillary  ganglion ; 
15,  the  submaxillary  ganglion;  16,  filaments  of  communication  with  the  lingual  nerve;  17, 
the  glosso-pharyngeal  nerve;  18,  the  pneumogastrio  or  par  vagum  nerve;  19,  the  three  upper 
cervical  nerves;  20,  the  four  inferior  cervical  nerves;  21,  the  first  dorsal  nerve;  22,  23,  the 
brachial  plexus;  24,  25,  the  phrenic  nerve;  26,  the  carotid  artery;  27,  the  internal  jugular 
vein.] 

*  See  his  "Physiol.,  Pathol.,  and  Anat.  Kesearcb.es,"  p.  151;  and  "Edinb.  Med.  ana 
Surg.  Journ.,"  Jan.,  1838. 

a  '  Recherches  Expe"rimentales  sur  les  Fonctions  du  Nerf  Spinal,'  in  "Archives  de 
MeMecine,"  1844. — This  Memoir,  having  gained  the  prize  given  by  the  Acade'mie  des 
Sciences  for  experimental  physiology  in  1845,  has  been  printed  in  the  "  Recueil  des  Sa- 
vnnts  etrangers,"  torn,  xi.,  1851  :  and  the  author  states  that  since  the  first  publication  of 
his  researches,  he  has  confirmed  his  original  conclusions  by  the  repetition  and  variation 
of  his  experiments. 


470  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

of  this  nerve  is  restricted  to  the  muscles  of  the  tongue,  is  a  point  very  easily 
established  by  anatomical  research;  and  accordingly  we  find  that,  long  before 
the  time  of  Sir  C.  Bell,  Willis  had  spoken  of  it  as  the  nerve  of  the  motions 
of  articulation,  whilst  to  the  Lingual  branch  of  the  5th  pair  he  attributed 
the  power  of  exercising  the  sense  of  taste ;  and  he  distinctly  stated,  that  the 
reason  of  this  organ  being  supplied  with  two  nerves,  is  its  double  function 
The  inference  that  it  is  chiefly,  if  not  entirely,  a  motor  nerve,  which  has  been 
founded  upon  its  anatomical  distribution,  is  supported  also  by  the  nature  of  its 
origin,  which  is  usually  from  a  single  root,  corresponding  to  the  anterior  root  of 
the  Spinal  nerves.  Experiment  shows  that,  when  the  trunk  of  the  nerve  is 
stretched,  pinched,  or  galvanized,  violent  motions  of  the  whole  tongue,  even  to 
its  tip,  are  occasioned ;  and  also,  that  similar  movements  take  place  after  divi- 
sion of  the  nerve,  when  the  cut  end  most  distant  from  the  brain  is  irritated.  In 
regard  to  the  degree  in  which  this  nerve  possesses  sensory  properties,  there  is 
some  difference  of  opinion  amongst  physiologists,  founded,  as  it  would  seem,  on  a 
variation  in  this  respect  between  different  animals.  Indications  of  pain  are 
usually  given,  when  the  trunk  is  irritated  after  its  exit  from  the  cranium  ;  but 
these  may  proceed  from  its  free  anastomosis  with  the  cervical  nerves,  which  not 
improbably  impart  sensory  fibres  to  it.  But  in  some  Mammalia,  the  hypoglossal 
nerve  has  been  found  to  possess  a  small  posterior  root  with  a  ganglion ;  this  is 
the  case  with  the  Ox,  and  also  in  the  Babbit;  and  in  the  latter  animal,  Valentin 
states  that  the  two  trunks  pass-out  from  the  cranium  through  separate  orifices,  and 
that,  after  their  exit,  one  may  be  shown  to  be  sensory,  and  the  other  to  be  motor. 
Hence,  this  nerve,  which  is  the  lowest  of  those  that  originate  in  the  cephalic  pro- 
longation of  the  spinal  cord  generally  known  as  the  medulla  oblongata,  approaches 
very  closely  in  some  animals  to  the  regular  type  of  the  spinal  nerves ;  and  though 
in  Man  it  still  manifests  an  irregularity,  in  having  only  a  single  root,  yet  this  ir- 
regularity is  often  shared  by  the  first  cervical  nerve,  which  also  has  sometimes  an 
anterior  root  only.  —  The  Hypoglossal  nerve  is  distributed  not  merely  to  the 
tongue,  but  to  the  muscles  of  the  neck  which  are  concerned  in  the  movements  of 
the  larynx ;  and  the  purpose  of  this  distribution  is  probably  to  associate  them  in 
those  actions,  which  are  necessary  for  articulate  speech.  Though  all  the  motions 
of  the  tongue  are  performed  through  the  medium  of  this  nerve,  yet  it  would 
appear,  from  pathological  phenomena,  to  have  at  least  two  distinct  connections 
with  the  nervous  centres ;  for  in  many  cases  of  paralysis,  the  masticatory  move- 
ments of  the  tongue  are  but  little  affected,  when  the  power  of  articulation  is 
much  injured  or  totally  destroyed;  and  the  converse  may  be  occasionally  noticed. 
When  this  nerve  is  paralysed  on  one  side,  in  hemiplegia,  it  will  be  generally 
observed  that  the  tongue,  when  the  patient  is  directed  to  put  it  out,  is  projected 
towards  the  palsied  side  of  the  face :  this  is  due  to  the  want  of  action  of  the 
lingual  muscles  of  that  side,  which  do  not  aid  in  pushing- forward  the  tip ;  the 
point  is  consequently  directed  only  by  the  muscles  of  the  other  side,  which  will 
not  act  in  a  straight  direction,  when  unantagonized  by  their  fellows.  It  is  a 
curious  fact,  however,  that  the  Hypoglossal  nerve  seems  not  to  be  always  palsied 
on  the  same  side  with  the  Facial,  but  sometimes  on  the  other.  This  has  been 
suggested  to  be  due  to  the  origination  of  the  roots  of  this  nerve  from  near  the 
point  at  which  the  pyramids  of  the  medulla  oblongata  decussate,  so  that  some  of 
its  fibres  come-off,  like  those  of  the  spinal  nerves,  without  crossing,  whilst  others 
are  transmitted  to  the  opposite  side,  like  those  of  the  higher  cephalic  nerves  ;  and 
the  cause  of  paralysis  may  affect  one  or  other  of  these  sets  more  particularly. 
Whatever  may  be  the  validity  of  this  explanation,  the  circumstance  is  an  inte- 
resting one  and  well  worthy  of  attention.1 

1  It  may  be  questioned,  however,  whether  the  Hypoglossal  is  really  paralyzed  on  the 
opposite  side  from  the  Facial  in  such  cases.  An  instance  has  been  communicated  to  the 
Author  by  Dr.  W.  Budd,  in  which  the  hypoglossal  nerve  was  completely  divided  on  one 
side ;  and  yet  the  tip  of  the  tongue,  when  the  patient  *as  desired  to  put  it  out,  was  some- 
times directed  from  and  sometimes  towards  the  palsied  side;  showing  that  the  muscles  of 
either  half  are  sufficient  to  give  any  required  direction  to  the  whole. 


HYPOGLOSSAL  NERVE. — CEPHALIC  NERVES  IN  GENERAL. 


4T1 


500  The  yeneral  homoloyy  of  the  Cephalic  nerves,  considered  with  reference 
to  the  ordinary  Spinal,  constitutes  a  study  of  much  interest.  It  appears,  from 
what  has  been  already  stated,  that  the  Pneumogastric,  Spinal  Accessory,  Glosso- 
pharyngeal,  and  Hypoglossal  nerves,  may  be  considered  nearly  in  the  light  of 
ordinary  Spinal  nerves.  They  all  take  their  origin  exclusively  in  the  Medulla 

«. 

[Fia.  141. 


The  drawing  exhibits  the  cerebral  connection  of  all  the  cerebra^  nerves  except  the  1st.  It 
is  from  a  sketch  taken  from  two  dissections  of  this  part.  D.  Posterior  optic  tubercle.  The 
generative  bodies  of  the  thalamus  are  just  above  it.  E.  Cerebellum.  H.  Spinal  cord.  I.  Tuber 
cinereum.  K.  Optic  thalamus  divided  perpendicularly,  w.  Corpus  restiforme.  x.  Pons  Va- 
rolii.  b  b.  Optic  nerves  :  this  nerve  is  traced  on  the  left  side  back  beneath  the  optic  thalamus 
and  round  the  crus  cerebri.  It  divides  into  four  roots  ;  the  first  (g  g)  plunges  into  the  substance 
of  the  thalamus,  the  next  runs  over  the  external  geniculate  body  and  surface  of  the  thalamus, 
the  third  goes  to  the  anterior  optic  tubercle,  the  fourth  runs  to  D,  the  testis  or  posterior  optic 
tubercle,  c.  Third  pair  common  oculo-muscular,  arising  by  two  roots  like  the  spinal  roots  of 
the  spinal  nerves,  the  upper  from  the  gray  neurine  of  the  locus  niger,  the  lower  from  the  con- 
tinuation of  the  pyramidal  columns  in  the  crus  cerebri  and  Pons  Varolii,  p  t.  d.  Fourth  pair, 
apparently  arising  from  the  inter-cerebral  commissure  (i  c),  but  really  plunging  down  to  the 
olivary  tract  (o  t)  as  it  ascends  to  the  optic  tubercles,  e  m.  Motor  or  non-ganglionic  root  of  the 
fifth  pair,  arising  from  the  posterior  edge  of  the  olivary  tract,  e.  Sensory  root  of  the  fifth  pair 
running  down  between  the  olivary  tract  and  restiform  body  to  the  sensory  tract.  /.  Sixth  pair, 
or  abducens,  arising  from  the  pyramidal  tract,  g.  Seventh  pair,  facial  nerve,  or  portio  dura, 
arising  by  an  anterior  portion  from  the  olivary  tract  and  by  a  posterior  portion  from  the  cere- 
bellic  fibres  of  the  anterior  columns  as  they  ascend  on  the  corpus  restiforme,  w.  h.  Eighth  pair, 
portio  inollis,  or  auditory  nerve,  with  its  two  roots  embracing  the  restiform  body.  ?.  Ninth 
pair,  or  glosso-pharyngeal ;  andj.  Tenth  pair,  or  par  vagum,  plunging  into  the  restiform  gan- 
glion, j  j.  Fibres  of  the  optic  nerve  plunging  into  the  thalamus ;  immediately  below  tbeso 
letters  is  the  corpus  geniculatum  externum.  k.  Eleventh  pair,  or  lingual  nerve ;  the  olivary 
body  has  been  nearly  sliced  off  and  turned  out  of  its  natural  position  ;  some  of  the  filaments 
of  the  lingual  nerve  are  traced  into  the  deeper  portion  of  the  ganglion,  which  is  left  in  its 
situation;  others  which  are  the  highest  are  evidently  connected  with  the  pyramidaJ  tract.1—  ED,] 

1  ["Solly  on  the  Brain,"  Am.  Ed.] 


472  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

Oblongata;  and  the  want  of  correspondence  in  position,  between  their  roots  and 
those  of  the  Spinal  nerves,  is  readily  accounted-for,  by  the  alteration  in  the  direc- 
tion of  the  columns  of  the  Spinal  cord,  which  not  only  decussate  laterally,  but, 
as  it  were,  antero-posteriorly  (§  489).  The  Hypoglossal,  as  just  stated,  not  un- 
i'requently  possesses  a  sensory  in  addition  to  its  motor  root.  The  Glosso-pharyn- 
geal,  which  is  principally  an  afferent  nerve,  has  a  small  motor  root ;  but  most  of 
the  motor  fibres  which  answer  to  it  are  to  be  found  in  the  Pneumogastric.  That 
the  Pneumogastric  and  Spinal  Accessory  together  represent  a  Spinal  nerve,  may 
bo  regarded  as  probable  from  what  has  been  already  said  of  their  relations.  — 
Leaving  these  nerves  out  of  the  question,  therefore,  we  proceed  to  the  rest. 
Comparative  anatomy,  and  the  study  of  Embryonic  development,  alike  show  that 
the  Spinal  Cord  and  the  Medulla  Oblongata  constitute  the  most  essential  part  of 
the  nervous  system  in  Vertebrata;  and  that  the  Cerebral  Hemispheres  are  super- 
added,  as  it  were,  to  this.  At  an  early  period  of  development,  the  Encephalon 
consists  chiefly  of  four  vesicles,  which  correspond  with  the  ganglionic  enlarge- 
ments of  the  nervous  cord  of  the  Articulata,  and  mark  four  divisions  of  the 
Cerebro-Spinal  axis,  and,  in  accordance  with  this  view,  the  Osteologist  is  able  to 
trace,  in  the  bones  of  the  cranium,  the  same  elements  which  would  form  four 
vertebrae,  in  a  much  expanded  and  altered  condition.1  The  four  pairs  of 
nerves  of  special  sensation,  —  Auditory,  Gustatory,  Optic,  and  Olfactory, — 
make  their  way  out  through  these  four  cranial  vertebras  respectively.  At  a 
later  period  of  development  other  nerves  are  interposed  between  these;  which, 
being  intervertebral,  are  evidently  more  analogous  to  the  Spinal  nerves,  both  in 
situation  and  function.  A  separation  of  the  primitive  fibres  of  these  takes  place, 
however,  during  the  progress  of  development,  so  that  their  distribution  appears 
irregular.  Thus  the  greater  part  of  the  sensory  fibres  are  contained  in  the  large 
division  of  the  Trigeminus;  whilst  of  the  motor  fibres,  the  anterior  set  chiefly 
pass  forwards  as  the  Oculo-motor  and  Patheticus ;  and  of  the  posterior,  some  form 
the  small  division  of  the  Trigeminus,  and  others  unite  with  the  first  pair  from 
the  Medulla  Oblongata  to  form  the  Facial.  This  last  fact  explains  the  close 
union,  which  is  found  in  Fishes  and  some  Amphibia,  between  that  nerve  and 
those  proceeding  more  directly  from  the  Medulla  Oblongata.  According  to  Va- 
lentin, the  Glosso-pharyngeal  is  the  sensory  portion  of  the  first  pair  from  the 
Medulla  Oblongata,  of  which  the  motor  part  is  chiefly  comprehended  in  the 
Facial  nerve.  Although  we  are  accustomed  to  consider  the  Fifth  pair  as  par 
eminence  the  Spinal  nerve  of  the  head,  the  foregoing  statements,  founded  upon 
the  history  of  development,2  show  that  the  nerves  of  the  Orbit  really  belong  to 
its  motor  portion;  they  may  consequently  be  regarded  as  altogether  forming  the 
first  of  the  intervertebral  nerves  of  the  cranium.  The  Facial  and  Glosso-pharyn- 
geal appear  to  constitute  the  second ;  whilst  the  Par  Vagum  and  Spinal  Acces- 
sory, forming  the  third  pair,  intervene  between  this  and  the  true  Spinal,  of  which 
the  Hypoglossal  may  be  considered  as  the  first. 

501.  Functions  of  the  Spinal  Axis.  —  In  considering  the  functions  of  the 
Spinal  Cord,  we  have  to  regard  it  under  two  aspects ;  —  In  the  first  place  as  a 
conductor  of  nervous  force  between  the  Nerve-trunks  and  the  Encephalic 
centres;  —  and  in  the  second  place,  as  itself  an  independent  centre  of  nervous 
power.  As  a  mere  conductor  of  nervous  force,  its  functions  are  the  same  as 
those  of  a  nerve-trunk ;  for  if  it  be  divided,  all  the  parts  of  the  body  which  are 
solely  supplied  by  nerves  coming-off  below  the  point  of  section  are  completely 
paralyzed,  as  far  as  regards  sensibility  and  voluntary  movement;  no  impressions 
made  upon  them  having  the  least  power  to  affect  the  consciousness,  and  no  exer- 
tion of  the  will  being  able  to  determine  contraction  of  their  muscles.  This  state 

1  See  Prof.  Owen's  "Archetype  Skeleton;"  and  the  Author's  "Princ.  of  Gen.  Phys.," 
Am.  Ed. 

1  On  this  point,  as  well  as  on  the  functions  of  the  Cephalic  nerves  generally,  see  Prof. 
Valentin  "  De  Functionibus  Nervorum  Cerebralium  et  Nervi  Sympathici."  Bernse,  1839. 


FUNCTIONS     OF    THE    SPINAL    CORD.  47o 

of  paraplegia,  which  may  be  experimentally  induced  in  animals,  is  frequently 
exhibited  in  Man  as  a  result  of  injury  or  of  disease  which  seriously  implicates 
the  Spinal  Cord  j  and  as  it  has  been  shown  that  among  the  lower  animals  com- 
plete reunion  of  the  Cord  may  take  place  after  complete  division,  as  indicated  by 
the  entire  restoration  of  its  functional  powers  and  tfce  complete  redintegration 
of  its  structure,1  so  have  we  reason  to  believe  that  a  similar  regeneration  may 
take  place  to  a  considerable  extent  in  Man,  this  being  marked  by  the  gradual 
return  of  sensibility  and  power  of  voluntary  movement  in  the  lower  limbs  which 
had  been  at  first  completely  paralysed.  This  regeneration  is  of  course  less 
likely  to  occur  in  cases  of  disease,  when  the  parts  around  are  in  an  unhealthy 
state,  than  when  the  paralysis  is  due  to  injury,  which  all  the  restorative  powers 
of  the  system  are  engaged  in  repairing  ;  but  it  is  to  be  remembered,  that  as  the 
injuries  which  are  likely  to  cause  such  lesions  of  the  Cord,  are  nearly  always 
attended  with  severe  concussion  (it  being  very  rare  for  the  Cord  to  be  accidentally 
wounded  by  the  penetration  of  a  sharp  instrument  between  the  vertebrae,  in  the 
mode  in  which  experiments  are  made  upon  animals),  some  of  their  first  effects 
are  attributable  to  the  shock  which  it  has  sustained ;  so  that  the  partial  recovery 
which  takes-place  at  an  early  period,  must  not  be  regarded  as  the  result  of  regene- 
ration of  nervous  tissue,  which  requires  a  much  longer  time  for  its  completion. 

502.  The  conducting  power  of  the  entire  Spinal  Cord  being  thus  established, 
we  have  next  to  inquire  whether  any  difference  in  endowment  can  be  shown  to 
exist  in  its  several  columns.  By  Sir  C.  Bell,  it  was  supposed  that  the  anterior 
columns  possess  the  same  endowments  as  the  anterior  roots  of  the  nerves,  and 
the  posterior  columns  the  same  as  the  posterior  roots  :  and  this  view  is  supported 
by  the  experiments  of  Longet,2  who  deduces  from  them  the  conclusion,  that 
irritation  of  the  posterior  columns,  as  of  the  posterior  nerve-roots,  gives  rise  to 
excruciating  pain,  without  exciting  any  other  movements  than  such  as  are  called 
into  action  in  reflex  respondence  to  the  impression ;  and  that  irritation  of  the 
anterior  columns  excites  movements  directly  (or  without  reflexion),  and  is  not  a 
source  of  pain.  Again,  he  found  that  when  the  Spinal  Cord  was  completely 
divided,  and  time  was  allowed  for  the  reflex  activity  of  the  cord  to  subside  (this 
disappearing  rapidly  in  adult  warm-blooded  animals),  the  application  of  an 
electric  current  to  the  posterior  columns  of  the  separated  part  occasioned  no  mus- 
cular action  whatever,  whilst  its  transmission  through  the  anterior  columns  called- 
forth  vigorous  movements.  Moreover,  he  states  that  the  effects  of  the  reversal 
of  the  electric  current,  transmitted  through  the  anterior  columns,  were  the  same 
as  those  of  the  same  reversal  when  the  currents  were  transmitted  through  the 
anterior  roots  of  the  spinal  nerves ;  whilst  they  differed  from  those  produced  by 
the  same  change  in  the  direction  of  the  currents,  transmitted  through  a  nerve 
of  mixed  endowments. — The  researches  of  Van  Deen 3  lead  on  the  whole  to  the 
same  conclusions  ;  but  they  tend,  in  his  opinion,  to  show  that  the  conducting 
power  both  of  the  anterior  and  posterior  columns  is  very  imperfect,  if  their 
white  strands  be  completely  separated  from  their  grey  matter.  His  experiments 
appear  to  have  conclusively  established  that  the  grey  matter  as  well  as  the  white, 
possesses  conducting  powers;  as  we  might  indeed  anticipate  from  the  circumstance, 
that  it  contains  a  large  amount  of  the  fibrous  form  of  nerve-tissue,  and  that  the 
commissural  connection  between  the  two  lateral  halves  of  the  Cord  is  established 
(according  to  Mr.  J.  L.  Clarke,  §  482)  by  its  grey  substance  alone.  That  a 
ready  transverse  communication  exists,  is  proved  not  merely  by  the  fact  that  an 
impression  made  upon  a  nerve  of  one  side  will  very  commonly  excite  reflex 

1  See  the  admirable  researches  of  M.  Brown-Se"quard,  in   "  Gazette  Me"dicale,"  1849 
No.  45,  and  1850,  No.  30;  also  the  "  Comptes  Rendus  de  la  Societe"  de  Biologic,"  1849, 
1850. 

2  "  Anatomic  et  Physiologic  du  Syst£me  Nerveux,"  1842  ;  and  "Traite  de  Physiologic,' 
1850,  torn.  ii.  pp.  184-8. 

'  "  Traite"s  et  Decouvertes  sur  la  Physiologie  et  la  Moelle  Epiniere,"  Leide,  1841. 


474  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

movements  on  both;  but" also  by  the  experiment  of  completely  dividing  one  half 
of  the  cord  as  far  as  the  median  line,  and  dividing  the  other  half  to  the  same 
extent  a  short  distance  below  the  first  section ;  for  this  operation  does  not  inter- 
rupt the  transmission  of  sensory  impressions,  although  it  seems  doubtful  whether 
motor  influences  can  be  thus  propagated.1 — The  experimental  results  of  Stilling,2 
again,  are  on  the  whole  in  harmony  with  the  preceding;  but  he  lays  yet  greater 
stress  than  Van  Deen,  on  the  importance  of  the  grey  matter  to  even  the  con- 
ductive power  of  the  white. — These  deductions,  however,  are  strongly  opposed 
by  Longet;  who  affirms  that  he  could  never  obtain  any  evidence  either  of  sensi- 
bility or  of  motor  power,  on  irritating  the  grey  substance  alone  by  the  electric 
current;  and  that,  on  the  other  hand,  the  entire  destruction  of  the  grey  matter 
for  a  considerable  length,  by  means  of  a  rod  introduced  into  the  interior  of  the 
Cord,  did  not  seem  in  any  degree  to  impair  the  conducting  power  of  its  columns. 

503.  It  must  be  freely  admitted,  however,  that  there  are  numerous  Patholo- 
gical phenomena,  which  it  is  very  difficult  to  reconcile  with  any  of  the  foregoing 
conclusions  regarding  the  relative  functions  of  the  anterior  and  posterior  columns 
of  the  Spinal  Cord :  cases  having  been  recorded,  in  which  complete  destruction 
of  the  anterior  columns  appeared  to  have  taken  place,  without  loss  of  voluntary 
motion  in  the  parts  below;  whilst  a  similar  destruction  of  the  posterior  columns 
has  occurred,  without  corresponding  lesion  of  sensibility.3  But  it  must  be 
borne  in  mind  that  we  are  still  far  from  having  an  accurate  knowledge  of  the 
degree  of  structural  change  in  the  nervous  centres,  which  is  incompatible  with 
the  continued  performance  of  their  functions;  and  that  there  are  instances  in 
which  the  whole  thickness  of  the  cord  has  undergone  softening  and  apparent 
disintegration,  without  the  destruction  of  the  functional  connection  between  the 
Encephalon  and  the  parts  below  the  seat  of  the  disease.4 

[It  is  a  well  known  fact  that  lesion  of  one  side  of  the  brain  produces  loss  of 
motion  and  sensibility  on  the  opposite  side  of  the  body,  and  the  explanation  is, 
that  decussation  of  the  motor  and  sensitive  fibres  takes  place  in  the  Medulla  Oblon- 
gata.  Until  lately,  the  experiments  of  Galen  have  been  considered  as  proving 
that  there  is  no  decussation  in  the  Spinal  Cord.  The  experiments  of  Dr.  Brown- 
Sequard  on  animals,  repeated  by  the  editor,  and  some  pathological  facts  collected 
by  the  same  careful  observer,  are  partly  opposed  to  the  view  attributed  to  Galen. 
He  has  found,  that  although  it  is  true  that  all  the  motor  fibres  do  not  cross  each 
other  in  the  Spinal  Cord,  the  sensitive  fibres  unquestionably  do,  so  that  in  the  case 
of  a  lesion  of  the  right  side  of  the  Spinal  Cord,  there  will  occur  a  loss  or  dirni- 

1  A  case  is  cited  by  Longet  from  Begin,  in  which  a  man  was  stabbed  at  the  back  of  the 
neck,  the  point  of  the  knife  passing  obliquely  forwards  between  the  sixth  and  seventh 
cervical  vertebrae,  dividing  the  antero-lateral  and  anterior  columns  of  the  Spinal  Cord  on 
the  right  side.  He  survived  the  injury  six  days  ;  and  suffered  from  complete  paralysis  of 
motion  of  the  corresponding  lower  extremity,  with  incomplete  paralysis  of  motion  of  the 
right  arm  ;  the  sensibility  remaining  perfect.  This  case  seems  to  show  that  the  Will  has 
no  power  to  direct  its  motor  impulses  across  the  cord ;  since  the  parts  deriving  their  nerves 
from  the  part  of  the  cord  below  the  partial  section,  were  entirely  withdrawn  from  its  in- 
fluence. 

*  "  Untersuchungen  iiber  die  Functionen  des  Riickenmarks  und  die  N erven,"  Leipzig, 
1842. 

3  See  especially  the  case  recorded  by  Mr.  Stanley  in  "  Med.-Chir.  Transact.,"  vol.  xx'ii. 
and  by  Dr.  Webster,  Op.  cit.,  vol.  xxvi. 

*  See,  for  example,  the  case  of  '  Softening  of  the  Spinal  Marrow,'  recorded  by  Dr.  Nairne 
in  the  "  Med.-Chir.  Trans.,"  vol.  xxxiv. ;  in  which  a  portion  of  the  Cord  at  least  an  inch 
long,  situated  opposite  the  third  and  fourth  dorsal  vertebra,  was  "  so  soft  that  the  slightest 
pressure  of  the  finger  broke  it  up,"  being  nearly  in  a  fluid  state  through  its  whole  thick- 
ness ;  yet  the  patient  felt  pain  in  his  lower  limbs,  showing  that  the  power  of  upward 
transmission  remained  ;  and  although  he  had  lost  all  Voluntary  control  over  the  muscles  of 
the  lower  part  of  the  body,  yet  they  were  affected  with  incessant  choreic  movement  (which, 
as  will  be  shown  hereafter,  Sect.  8,  appears  to  originate  in  the  Sensory  Ganglia),  and  these 
movements  were  affected  in  such  a  marked  manner  by  emotions,  as  plainly  to  indicate  a 
downward  transmission  of  motor  power. 


FUNCTIONS    OF    THE    SPINAL    CORD.  475 

nution  of  voluntary  movements  on  the  right  side  of  the  body,  and  a  diminution 
or  loss  of  sensibility  on  the  left  side,  and  vice  versaX 

The  facts  which  prove  this  cross-action  of  the  afferent  or  sensitive  nerve-fibres, 
are  as  follows  : — 

1st.  If  a  lateral  half  of  the  spinal  cord  is  divided  transversely  at  the  level  of 
the  tenth  costal  vertebra,  on  a  Mammal,  it  is  found  that* sensibility  is  much  dimi- 
nished and,  in  some  cases,  entirely  abolished  in  the  posterior  limb  opposite  to  the 
side  of  the  section.  On  the  contrary,  the  sensibility,  far  from  being  lost,  appears 
to  be  much  increased,  in  the  posterior  limb,  on  the  side  on  which  the  section  haa 
been  made. 

2d.  If,  instead  of  one  transversal  hemisection  of  the  cord,  two,  three,  or  more 
are  made,  on  the  same  side,  the  same  effects  are  observed. 

3d.  If,  instead  of  mere  sections,  a  removal  of  a  lateral  half  of  the  spinal 
marrow  is  effected,  the  same  results  are  still  obtained.  For  the  performance  of 
this  experiment  a  longitudinal  section,  one  inch  in  length,  is  first  made  in  the 
median  plane  of  the  cord,  and  then  two  transversal  sections  on  one  side  are  made 
at  the  extremities  of  the  longitudinal  one,  so  that  a  part  of  the  cord  is  com- 
pletely separated  from  the  rest  and  removed. 

4th.  If  the  lateral  section  is  not  complete,  and  if  the  part  left  undivided  is  in 
the  neighbourhood  of  the  centre  of  the  cord,  it  is  found  that  sensibility  appears 
to  be  increased  in  the  posterior  limb  on  the  same  side,  and  that  in  the  other 
posterior  limb  there  is  only  a  slight  diminution  of  sensibility.  If  the  part  left 
undivided  is  considerable,  sensibility  does  not  appear  to  be  diminished  in  this 
last  limb,  and  sometimes  it  seems  rather  increased. 

5th.  If,  in  performing  the  section  of  a  lateral  half  of  the  spinal  cord,  the  in- 
strument goes  a  little  too  far  and  divides  also  a  small  portion  of  the  other  half 
in  the  central  part,  then  the  posterior  limb  on  the  side  of  the  complete  section 
is  less  sensitive  than  in  the  normal  state,  and  the  posterior  limb  of  the  opposite 
side  loses  its  sensibility  completely. 

6th.  If  the  section  of  a  lateral  half  of  the  spinal  cord  is  made  at  the  level  of 
the  second  or  third  cervical  vertebra,  it  is  found  that  sensibility  becomes  very 
quickly  much  greater  in  the  parts  of  the  body  on  the  side  of  the  section,  and 
that,  on  the  contrary,  the  parts  on  the  other  side  become  evidently  less  sensitive. 

Before  proceeding  farther  in  the  exposition  of  these  experiments,  it  is  neces- 
sary to  examine  here  the  results  already  related.  It  is  clear  that  if  the  trans- 
mission of  sensitive  impressions  were  effected  in  the  spinal  cord,  according  to 
the  generally  admitted  theory,  we  should  find,  after  the  section  of  a  lateral  half, 
sensibility  lost  or  at  least  diminished  on  the  corresponding  side  of  the  body,  and 
almost  normal  on  the  other  side.  We  find  exactly  the  reverse :  that  the  side 
which  should  have  lost  its  sensibility  does  not  lose  it  at  all,1  and  the  one  which 
should  have  retained  its  sensibility  loses  it  almost  entirely. 

Dr.  Brown-Sequard  concludes  that  the  generally  accepted  theory  is  wrong,  and 
that  there  appears  to  be  a  decussation  of  sensory  fibres  in  the  spinal  cord. 
The  following  experiments  are  still  more  decisive  proofs  that  this  is  the  real 
state  of  things. 

7th.  If  after  a  section  of  the  lateral  half  of  the  spinal  cord  at  the  level  of 
the  eleventh  costal  vertebra,  we  perform  the  section  of  the  other  lateral  half,  at 
the  level  of  the  sixth  costal  vertebra;  so  that  the  two  lateral  halves  of  the  cord 
are  cut  transversely,  we  find  that  sensibility  is  entirely  lost,  or  very  nearly  so,  in 
the  two  posterior  limbs.  Sometimes  a  very  slight  degree  of  sensibility  remains, 
more  particularly  in  the  posterior  limb  on  the  side  where  the  spinal  cord  has 
been  divided  at  the  level  of  the  sixth  costal  vertebra. 

8th.  If  two  sections  of  lateral  halves  are  made  as  in  the  preceding  experi- 

1  Far  from  being  lost,  sensibility  appears  to  be  much  increased. 


476  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

ment,  but  at  a  greater  distance,  one  from  the  other,  for  instance,  one  on  the  right 
side,  at  the  level  of  the  eleventh  costal  vertebra,  and  the  other  on  the  left  side, 
in  the  cervical  region,  nearly  the  same  results  are  obtained  as  regards  the  poste- 
rior limbs,  but  the  sensibility  is  increased  in  the  right  anterior  limb  and  it  re- 
mains, though  much  diminished,  in  the  left  anterior  limb. 

9th.  If,  after  having  divided  transversely  a  lateral  half  of  the  spinal  cord,  in 
the  neck,  at  the  level  of  the  roots  of  the  second  pair  of  nerves,  we  lay  bare  the 
very  sensitive  nerves  going  to  the  ear,  in  dogs  or  rabbits,  we  find  that  their  sen- 
sibility, on  the  side  of  the  section  of  the  cord,  appears  increased,  and  that,  on  the 
contrary,  on  the  other  side,  they  appear  either  destitute  of  sensibility  or  very 
slightly  sensitive. 

10th.  Sections  of  a  lateral  half  of  the  medulla  oblongata  give,  as  regards  sen- 
sibility, the  same  results  as  sections  of  a  lateral  half  of  the  spinal  cord. 

llth.  If  a  longitudinal  section  be  made  on  the  part  of  the  spinal  cord  giving 
nerves  to  the  posterior  extremities,  so  as  to  divide  that  part  into  two  lateral 
halves,  then  it  is  found  that  sensibility  is  completely  lost  in  the  two  posterior 
limbs,  although  voluntary  movements  take  place  in  them.  This  is  one  of  the  ex- 
periments of  Galen,  but  he  does  not  speak  of  sensibility. 

12th.  If  n  similar  separation  of  the  two  lateral  halves  of  the  spinal  cord  be 
made  on  the  whole  part  supplying  nerves  to  the  anterior  limbs,  then  we  find  that 
sensibility  is  lost  in  both  these  limbs,  and  that  it  is  only  slightly  diminished  in 
the  posterior  limbs. 

13th.  If  the  same  operation  be  performed  as  in  the  preceding  experiment,  and 
if  afterwards  a  transversal  division  be  made  on  one  of  the  lateral  halves  of  the 
cord  in  the  part  where  the  longitudinal  section  has  been  made,  then  we  find  that 
the  posterior  limb  on  the  side  of  the  transversal  section  remains  sensitive,  and 
that  the  other  posterior  limb  loses  its  sensibility. 

It  is  not  necessary  to  stop  to  show  that  these  experiments  all  prove  that  the 
transmission  of  sensitive  impressions  made  on  one  side  of  the  body  takes  place, 
at  least  for  a  great  part,  along  the  opposite  side  of  the  spinal  cord,  and  that  there 
is,  consequently,  a  crossing  of  the  sensitive  nerve-fibres  of  the  spinal  cord. 

To  ascertain  the  degree  of  sensibility,  various  modes  of  excitation,  mechani- 
cal, galvanic,  physical  (i.  e.,  warmth  and  cold),  and  chemical,  were  used. 

A  proper  use  of  galvanism  and  of  a  red-hot  iron  are  the  best  means  of  ascer- 
taining the  presence  and  the  degree  of  sensibility.  When  a  slight  pilvanic  cur- 
rent is  employed,  it  gives  no  pain  if  applied  to  limbs  in  which  sensibility  is 
much  diminished.  In  making  use  alternately  of  galvanic  currents  of  different 
energies,  we  are  enabled  to  find  what  is  the  degree  of  sensibility  of  the  different 
parts  of  the  body. 

There  cannot  be  any  doubt  that  these  experiments  prove  that  there  is  a  cross- 
ing of  sensitive  nerve-fibres  in  the  spinal  cord,  but  there  are  some  questions  that 
they  do  not  so  clearly  solve,  and  such  are  the  following.  Do  all  the  sensitive 
fibres  cross  each  other  in  the  spinal  cord  ?  and  if  some  do  not,  what  is  their  pro- 
portion to  those  which  do  pass  from  one  side  of  the  cord  to  the  other  ?  The 
truth  is  that  very  nearly  all  the  sensitive  nerve-fibres,  coming  from  the  trunk 
and  limbs,  cross  each  other  in  the  spinal  cord,  and  that,  in  consequence,  the 
transmission  of  the  sensitive  impressions,  made  upon  one  side  of  the  body,  takes 
place  almost  entirely  along  the  opposite  side  of  the  spinal  cord.  This  conclusion 
is  also  maintained  by  pathological  cases  detailed  by  the  author,  in  which  lesions 
of  one  side  of  the  spinal  cord  in  Man  showed  the  same  results.1 — ED.] 

504.  It  is  no  less  difficult  to  reconcile  with  the  experimental  results  already 
cited,  those  of  other  Physiologists,  which  appear  to  show  that  the  anterior  and 
posterior  divisions  of  the  Spinal  Cord  respectively  minister  to  the  motions  of 
flexion  and  extension.  This  notion,  which  originated  with  Bellengeri,2  was  after- 

1  [Vide  "  Virginia  Medical  and  Surg.  Journ.,"  March,  1855 — ED.] 

3  "  De  Medulla  Spinali,  nervisque  ex  ea  prodeuutibus,"  &c.,  Turin,  1823. 


FUNCTIONS     OF    THE     SPINAL     CORD.  477 

wards  advocated  by  Valentine,'  who  inferred  from  his  experiments,  that  if  the 
posterior  column  of  the  Spinal  Cord  of  the  Frog  be  irritated  at  the  point  at  which 
the  nerves  of  either  extremity  are  given-off,  that  extremity  is  extended,  and  that 
if  the  anterior  column  be  irritated,  the  extremity  is  flexed;  so  that,  since  he 
admitted  the  anterior  columns  to  be  chiefly  motor,  and  the  posterior  to  be  for  the 
most  part  sensory,  it  would  appear  that  the  motor  fibres  of  the  extensors  pass 
from  the  anterior  into  the  posterior  column,  whilst  those  of  the  flexors  are  con- 
tinued onwards  in  the  anterior  column.  Confirmation  of  this  inference  was 
obtained  by  Valentin  from  experiments  on  Mammalia;  and  it  is  borne-out,  in  his 
opinion,  by  pathological  phenomena  observed  in  Man.  According  to  this  emi- 
nent physiologist,  also,  relaxation  of  the  sphincters  is  analogous  to  the  extended 
state  of  the  extremities;  and  he  has  noticed  a  manifest  relaxation  of  the  sphincter 
ani  in  the  frog,  when  the  superior  part  of  the  spinal  cord  was  irritatod,  so  as  to 
produce  extension  of  the  limbs.  The  experiments  of  Budge2  and  Engelhart,3 
however,  led  them  to  an  opposite  conclusion ;  for  it  appeared  to  them  that,  in 
Mammalia,  the  nerve-fibres  which  act  upon  the  extensor  muscles  are  contained  in 
the  anterior  columns,  and  those  of  the  flexor  muscles  in  the  posterior  columns ; 
whilst,  as  regards  the  Frog,  the  nerve-fibres  connected  with  the  extensor  muscles 
appeared  to  be  situated  posteriorly  to  those  of  the  flexors.  The  experiments  of 
Harless,4  again,  have  led  him  to  regard  the  upper  part  of  the  spinal  cord  in  the 
Frog,  between  the  2nd  and  4th  vertebrae  inclusive,  as  specially  concerned  in  the 
flexion  both  of  the  anterior  and  posterior  extremities ;  and  the  lower  part,  from 
the  5th  to  the  8th  vertebrae  inclusive,  as  in  like  manner  concerned  in  their  ex- 
tension.— All  these  results  can  only  at  present  be  accepted  as  indicating  that  somo 
such  special  arrangement  of  the  nerve-fibres  in  the  Spinal  Cord,  having  reference 
to  the  combination  of  different  muscular  actions  in  groups,  may  have  a  real 
existence ;  there  is  far  too  little  accordance,  however,  among  the  phenomena 
described  by  different  observers,  to  enable  even  a  probable  statement  to  be 
hazarded  in  regard  to  the  nature  of  this  arrangement;  and  it  seems  quite  possi- 
ble that  it  may  vary  in  different  animals,  in  accordance  with  their  respective 
modes  of  progression.  As  far  as  Man  is  concerned,  we  have  no  evidence  but 
that  of  pathological  phenomena;  and  we  certainly  may  find,  in  many  forms  of 
convulsive  action,  an  indication  that  there  is  some  common  centre  or  tract  of 
motor  impulse  for  the  extensor  muscles  generally,  and  another  such  centre  or 
tract  for  the  flexors.5 

505.  We  have  now  to  consider  the  Spinal  Cord  as  an  independent  centre  of 
nervous  power,  and  to  inquire  whether  the  movements  which  are  excited  through 
its  'reflex'  activity  necessarily  involve  sensation.  These  movements  are  most 
characteristically  displayed,  when  the  Spinal  Cord  is  cut-off  from  communication 
with  the  higher  Nervous  centres;  probably  rather  because  the  nerve-force  excited 
by  the  impression  reacts  through  the  Spinal  ganglion  to  which  it  is  conveyed,  when 
it  can  no  longer  pass-on  to  the  Encephalic  centres  (§  469),  than  because  (as  some 
suppose)  the  impulse  to  reflex  movement  is  ordinarily  neutralized  and  rendered 
inoperative  by  an  effort  of  the  will.  It  is  true  that  those  reflex  actions  of  the 
Spinal  Cord  which  are  necessary  to  the  maintenance  of  Organic  life,  and  which 
are  equally  performed  whether  the  Spinal  axis  be  in  communication  with  the 
higher  Encephalic  centres  or  not,  are  continually  modified  or  temporarily  sus- 
pended by  the  Will ;  but  this  is  only  when  we  consciously  bring  the  Will  to 
bear  upon  them;  and  it  is  no  less  certain  that  we  are  not  continually  making 

1  "De  Functionibus  Nervorum  Cerebralium  et  Nervi  Sympathici,"  Bernse,  1830. 

a  "  Untersuchungen  iiber  das  Nervensystem,"  1841. 

8  «  Muller's  Archiv.,"  heft  3,  1841.  4  "  Muller's  Archiv.,"  1846. 

8  Thus  in  a  case  of  Hysteric  Paraplegia,  which  was  for  some  time  under  the  Authoi's 
observation,  the  extensors  only  of  the  limbs  were  paralysed,  the  will  retaining  its  ordinary 
power  over  the  flexors.  And  in  ordinary  Cramp,  of  which  the  patient  just  mentioned  was 
subject  to  extremely  severe  attacks,  the  flexors  alone  are  usually  in  action. 


478  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

any  such  exertions,  in  order  to  antagonize  movements,  which  (as  we  learn  from 
Pathological  evidence),  would  be  continually  excited  but  for  this  neutralizing 
influence,  if  such  a  doctrine  were  correct. — The  readiest  demonstration  of  the 
independent  power  of  the  Spinal  Cord,  is  derived  from  the  motions  exhibited  by 
the  limbs  of  animals,  when  irritation  is  applied  to  them  after  section  of  the  Spinal 
Cord  at  some  point  above  the  entrance  of  their  nerves;  the  fact  that  these  move- 
ments are  reflected  through  the  Cord,  and  are  not  the  product  of  direct  stimula- 
tion applied  to  the  part  irritated,  being;  shown  by  their  complete  cessation  when 
the  nerve-trunks  are  divided,  or  the  substance  of  the  Spinal  Cord  is  broken-down. 
Thus,  if  a  Frog  be  decapitated,  its  body  remains  supported  on  its  limbs  in  the 
usual  position,  and  will  recover  this  if  it  be  disturbed;  irritation  of  the  feet  will 
cause  it  to  leap;  and  tickling  the  cloaca  with  a  probe  will  excite  efforts  to  push 
away  the  instrument.1  It  is  to  be  observed  that  a  slight  irritation  applied  to  the 
peripheral  extremities  of  the  afferent  nerves,  is  a  more  powerful  excitor  of  reflex 
action,  than  a  much  stronger  impression,  which  occasions  acute  pain,  applied  to 
their  trunks;  thus  Mr.  Grainger  found  that  he  could  remove  the  entire  hind-leg 
of  a  Salamander  with  the  scissors,  without  the  creature  moving,  or  giving  any 
expression  of  suffering,  if  the  Spinal  Cord  had  been  first  divided;  yet  that  by 
irritation  of  the  foot,  especially  by  heat,  in  an  animal  similarly  circumstanced, 
violent  convulsive  actions  were  excited  in  the  legs  and  tail.  This  fact  is  import- 
ant, not  only  as  showing  the  comparatively-powerful  effect  of  impressions  upon 
the  cutaneous  surface,  but  also  as  proving  how  little  relation  the  amount  of  reflex 
action  has  to  the  intensity  of  sensation. 

506.  That  the  movements  executed  by  the  limbs  of  the  lower  animals,  when 
these  are  no  longer  connected  by  the  Spinal  Cord  with  the  Encephalon,  but 
remain  in  nervous  connection  with  the  Cord  itself,  do  not  take  place  through  the 
intermediation  of  sensation,  might  be  supposed  to  be  sufficiently  proved  by  the 
simple  fact,  that  division  of  the  Cord,  in  Man,  and  hence  by  inference  in  the 
lower  animals,  reduces  the  parts  below  to  a  state  of  complete  insensibility.  But, 
on  the  other  hand,  the  very  performance,  by  decapitated  animals  of  inferior  tribes, 
of  actions  which  had  not  been  witnessed  in  Man  under  similar  circumstances,  has 
been  held  to  indicate,  that  the  spinal  cord  in  them  has  an  endowment  which  his 
does  not  possess.  The  possibility  of  such  an  explanation,  however  u  neon  form  able 
to  that  analogy  throughout  organized  nature,  which,  the  more  it  is  studied,  the 
more  invariably  is  found  to  guide  to  truth,  could  not  be  disproved.  Whatever 
experiments  on  decapitated  animals  were  appealed-to?  in  support  of  the  doctrine 

1  It  has  been  pointed-out  by  Messrs.  Todd  and  Bowman,  ("  Physiological  Anatomy," 
p.  281,  Am.  Ed.),  that  the  Spinal  Cord  of  the  male  frog,  at  the  season  of  copulation,  naturally 
possesses  a  state  of  most  extraordinary  excitability.  The  thumb  of  each  anterior  extremity 
at  this  season,  becomes  considerably  enlarged ;  as  is  well  known  to  Naturalists.  "This 
enlargement  is  caused  principally  by  a  considerable  development  of  the  papillary  structure 
of  the  skin  which  covers  it ;  so  that  large  papillae  are  formed  all  over  it.  A  male  frog,  at 
this  season,  has  an  irresistible  propensity  to  cling  to  any  object,  by  seizing  it  between  his 
anterior  extremities.  It  is  in  this  way  that  he  seizes-upon,  and  clings-to  the  female ; 
fixing  his  thumbs  to  each  side  of  her  abdomen,  and  remaining  there  for  weeks,  until  the 
ova  have  been  completely  expelled.  An  effort  of  the  Will  alone  could  not  keep  up  the 
grasp  uninterruptedly  for  so  long  a  time  ;  yet  so  firm  is  the  hold,  that  it  cnn  with  difficulty 
be  relaxed.  "Whatever  is  brought  in  the  way  of  the  thumbs,  will  be  caught  by  the  forcible 
contraction  of  the  anterior  limbs  ;  and  hence  we  often  find  frogs  clinging  blindly  to  a  piece 
of  wood,  or  a  dead  fish,  or  some  other  substance  which  they  may  chance  to  meet  with. 
If  the  finger  be  placed  between  the  anterior  extremities,  they  will  grasp  it  firmly;  nor  will 
they  relax  their  grasp  until  they  are  separated  by  force.  If  the  animal  be  decapitated, 
whilst  the  finger  is  within  the  grasp  of  its  anterior  extremities,  they  still  continue  to  hold-on 
firmly.  The  posrerior  half  of  the  body  may  be  cut-away,  and  yet  the  anterior  extremities 
will  still  cling  to  the  finger ;  but  immediately  that  the  segment  of  the  Cord,  from  which 
the  anterior  extremities  derive  their  nerves,  has  been  removed,  all  their  motion  ceases. 
This  curious  instinct  only  exists  during  the  period  of  sexual  excitement;  for  at  other 
periods  the  excitability  of  the  anterior  extremities  is  considerably  less  than  that  of  the 
Dosterior." 


FUNCTIONS    OF    THE    SPINAL    COKD.  479 

that  the  Encephalon  contains  the  only  seat  of  sensibility,  could  be  met  by  a  simple 
denial  that  the  Spinal  Cord  is  everywhere  as  destitute  of  that  endowment,  as  it 
appears  to  be  in  Man.  The  cases  of  profound  Sleep  and  Apoplexy  might  be  cited 
as  examples  of  reflex  action  without  consciousness;  but  these  have  been  met  by 
the  assertion,  that  in  such  conditions,  sensations  are  felt,  though  they  are  not 
remembered.  It  is  difficult,  however,  to  apply  such  an  explanation  to  the  case 
of  Anencephalous  human  infants  (in  which  all  the  ordinary  reflex  actions  have 
been  exhibited,  with  an  entire  absence  of  brain),  without  supposing  that  the 
Medulla  Oblongata  is  the  seat  of  a  sensibility  which  we  know  that  the  lower  part 
of  the  Spinal  Cord  does  not  possess ;  and  of  this  there  is  no  evidence  whatever. — 
Experiments  on  the  lower  animals,  then,  and  observation  of  the  phenomena  mani- 
fested by  apoplectic  patients  and  anencephalous  infants,  might  lead  to  the  con- 
clusion, that  the  Spinal  Cord  does  not  itself  possess  sensibility,  and  that  its  reflex 
actions  are  independent  of  sensation.  At  this  conclusion,  Unzer,  Prochaska,  Sir 
Gr.  Blane,  Flourens,  and  other  physiologists,  had  arrived;  but  it  was  not  until 
special  attention  was  directed  to  the  subject  by  Dr.  M.  Hall,  that  facts  were 
obtained  by  which  a  positive  statement  of  it  could  be  supported.  For  the  ques- 
tion might  have  been  continually  asked, — If  the  Spinal  Cord  in  Man  be  pre- 
cisely analogous  in  function  to  that  of  the  lower  Yertebrnta,  why  are  not  its  reflex 
phenomena  manifested,  when  a  portion  of  it  is  severed  from  the  rest  by  disease 
or  injury?  The  answer  to  this  question  is  twofold.  In  the  first  place,  simple 
division  of  the  cord  with  a  sharp  instrument  leaves  the  separated  portion  in  a 
state  of  much  more  complete  integrity,  and  therefore  in  a  state  much  more  fit  for 
the  performance  of  its  peculiar  functions,  than  it  ordinarily  is  after  disease  or 
violent  injury;  and  as  the  former  method  of  division  is  one  with  which  the 
Physiologist  is  not  likely  to  meet  in  Man  as  a  result  of  accident,  and  which  he 
cannot  experimentally  put  in  practice,  the  cases  in  which  reflex  actions  would 
be  manifested  are  likely  to  be  comparatively  few.  But  secondly,  a  sufficient 
number  of  such  instances  have  now  been  accumulated  to  prove  that  the  occur- 
rence is  by  no  means  so  rare  as  might  have  been  supposed ;  and  that  nothing  is 
required  but  patient  observation,  to  throw  a  great  light  on  this  interesting  ques- 
tion, from  the  phenomena  of  disease.  A  most  valuable  collection  of  such  cases, 
occurring  within  his  own  experience,  has  been  published  by  Dr.  W.  Budd;1  and 
the  leading  facts  observed  by  him  will  be  now  enumerated. 

507.  In  the  first  case,  paraplegia  was  the  result  of  angular  distortion  of  the 
spine  in  the  dorsal  region.  The  sensibility  of  the  lower  extremities  was  ex- 
tremely feeble,  and  the  power  of  voluntary  motion  was  almost  entirely  lost. 
"  When,  however,  any  part  of  the  skin  is  pinched  or  pricked,  the  limb  that  is 
thus  acted-on  jumps  with  great  vivacity;  the  toes  are  retracted  towards  the  in- 
step, the  foot  is  raised  on  the  heel,  and  the  knee  so  flexed  as  to  raise  it  off  the 
bed ;  the  limb  is  maintained  in  this  state  of  tension  for  several  seconds  after  the 
withdrawal  of  the  stimulus,  and  then  becomes  suddenly  relaxed."  u  In  general, 
while  one  leg  was  convulsed,  its  fellow  remained  quiet,  unless  stimulus  was 
applied  to  both  at  once."  "  In  these  instances,  the  pricking  and  pinching  were 
perceived  by  the  patient ;  but  much  more  violent  contractions  are  excited  by  a 
stimulus,  of  whose  presence  he  is  unconscious.  When  a  feather  is  passed  lightly 
over  the  skin,  in  the  hollow  of  the  instep,  as  if  to  tickle,  convulsions  occur  in 
the  corresponding  limb,  much  more  vigorous  than  those  induced  by  pinching  or 
pricking;  they  succeed  one  another  in  a  rapid  series  of  jerks,  which  are  repeated 
as  long  as  the  stimulus  is  maintained."  "  When  any  other  part  of  the  limb  is 
irritated  in  the  same  way,  the  convulsions  which  ensue  are  very  feeble,  and  much 
less  powerful  than  those  induced  by  pricking  or  pinching."  "  Convulsions,  iden- 
tical with  those  already  described,  are  at  all  times  excited  by  the  acts  of  defeca- 
tion and  micturition.  At  these  times,  the  convulsions  are  much  more  vigorous 
than  under  any  other  circumstances,  insomuch  that  the  patient  has  been  obliged 
1  "  Medico-Chirurgical  Transactions,"  vol.  xxii. 


480  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

to  resort  to  mechanical  means  to  secure  his  person  while  engaged  in  these  acts. 
During  the  act  of  expulsion,  the  convulsions  succeed  one  another  rapidly,  the 
urine  is  discharged  in  interrupted  jets,  and  the  passage  of  the  faeces  suffers  a 
like  interruption."  The  convulsions  are  more  vigorous,  the  greater  the  accumu- 
lation of  urine;  and  involuntary  contractions  occur  whenever  the  bladder  is 
distended,  and  also  when  the  desire  to  relieve  the  rectum  is  manifested.  "  In 
all  these  circumstances,  the  convulsions  are  perfectly  involuntary;  and  he  is 
unable,  by  any  effort  of  the  will,  to  control  or  moderate  them."  The  patient 
subsequently  regained,  in  a  gradual  manner,  both  the  sensibility  of  the  lower 
extremities,  and  voluntary  power  over  them ;  and  as  voluntary  power  increased, 
the  susceptibility  to  involuntary  movements  diminished,  as  did  also  their  extent 
and  power. — This  case,  then,  exhibits  an  increased  tendency  to  perform  reflex 
actions,  when  the  control  of  the  brain  was  removed ;  and  it  also  shows  that  a 
slight  impression  upon  the  surface,  of  which  the  patient  was  not  conscious,  was 
more  efficacious  in  exciting  reflex  movements,  than  were  others  that  more  power- 
fully affected  the  sensory  organs. — It  should  be  added  that,  in  the  foregoing  case, 
the  nutrition  of  the  lower  extremities  was  not  impaired,  as  it  is  in  most  cases  of 
paraplegia ;  the  rationale  of  this  phenomenon,  which  is  to  be  constantly  observed 
when  the  reflex  actions  of  the  part  remain  entire,  will  be  understood  by  reference 
to  §§  358,  516. 

508.  In  another  case,  the  paralysis  was  more  extensive,  having  been  produced 
by  an  injury  (resulting  from  a  fall  into  the  hold  of  a  vessel)  at  the  lower  part 
of  the  neck.  There  was  at  first  a  total  loss  of  voluntary  power  over  the  lower 
extremities,  trunk,  and  hands ;  slight  remaining  voluntary  power  in  the  wrists, 
rather  more  in  the  elbows,  and  still  more  in  the  shoulders.  The  intercostal  mus- 
cles did  not  participate  in  the  movements  of  respiration.  The  sensibility  of  the 
hands  and  feet  was  greatly  impaired.  There  were  retention  of  urine,  and  invo- 
luntary evacuation  of  the  faeces.  Recovery  took  place  very  gradually;  and  dur- 
ing its  progress,  several  remarkable  phenomena  of  reflex  action  were  observed. 
At  first,  tickling  one  sole  excited  to  movement  that  limb  only  which  was  acted- 
upon ;  afterwards,  tickling  either  sole  excited  both  legs,  and,  on  the  26th  day, 
not  only  the  lower  extremities,  but  the  trunk  and  upper  extremities  also.  Irri- 
tating the  soles,  by  tickling  or  otherwise,  was  at  first  the  only  method,  and  always 
the  most  efficient  one,  by  which  convulsions  could  be  excited.  From  the  26th 
to  the  69th  day,  involuntary  movements  in  all  the  palsied  parts  continued  pow- 
erful and  extensive,  and  were  excited  by  the  following  causes :  in  the  lower 
extremities  only,  by  the  passage  of  flatus  from  the  bowels,  or  by  the  contact  of  a 
cold  urinal  with  the  penis;  convulsions  in  the  upper  extremities  and  trunk, 
attended  with  sighing,  by  plucking  the  hair  of  the  pubes.  On  the  41st  day,  a 
hot  plate  of  metal  was  applied  to  the  soles,  and  was  found  to  be  a  more  powerful 
excitor  of  movement  than  any  before  tried.  The  movements  continued  as  long 
as  the  hot  plate  was  kept  applied ;  but  the  same  plate,  at  the  common  tempera- 
ture, excited  no  movements  after  the  first  contact.  Though  the  contact  was 
distinctly  felt  by  the  patient,  no  sensation  of  heat  was  perceived  by  him,  even 
when  the  plate  was  applied  hot  enough  to  cause  vesication.  At  three  different 
intervals,  the  patient  took  one-eighth  of  a  grain  of  strychnia  three  times  a  day. 
Great  increase  of  susceptibility  to  involuntary  movements  immediately  followed, 
and  they  were  excited  by  the  slightest  causes.  No  convulsions  of  the  upper 
extremities  could  ever  be  produced,  however,  by  irritating  their  integument; 
though,  under  the  influence  of  strychnia,  pulling  the  hair  of  the  head,  or  tick- 
ling the  chin,  would  occasion  violent  spasmodic  actions  in  them.  Spontaneous 
convulsions  of  the  palsied  parts,  which  occurred  at  other  times,  were  more  fre- 
quent and  more  powerful  after  the  use  of  strychnia.  On  the  first  return  of 
voluntary  power,  the  patient  was  enabled  to  restrain  in  some  measure  the  excited 
vtiovements ;  but  this  required  a  distinct  effort  of  the  will ;  and  his  first  attempts 
("i  walk  were  curiously  affected  by  the  persistence  of  the  susceptibility  to  excited 


FUNCTIONS    OF    THE     SPINAL    CORD.  481. 

involuntary  movements.  "When  he  first  attempted  to  stand,  the  knees  imme- 
diately became  forcibly  bent  under  him  ;  this  action  of  the  legs  being  excited  by 
contact  of  the  soles  with  the  ground.  On  the  95th  day  this  effect  did  not  take 
place,  until  the  patient  had  made  a  few  steps;  the  legs  then  had  a  tendency  to 
bend-up,  a  movement  which  he  counteracted  by  rubbing  the  surface  of  the  belly ; 
this  rubbing  excited  the  extensors  to  action,  and  the  legs  became  extended  with 
[a  jerk.  A  few  more  steps  were  then  made,  the  manoeuvre  was  repeated,  and  so 
on.  This  susceptibility  to  involuntary  movements  from  impressions  on  the  soles, 
gradually  diminished;  and  on  the  141st  day,  the  patient  was  able  to  walk  about, 
supporting  himself  on  the  back  of  a  chair  which  he  pushed  before  him ;  but  his 
gait  was  unsteady,  and  much  resembled  that  of  chorea.  Sensation  improved 
very  slowly:  it  was  on  the  153rd  day  that  he  first  slightly  perceived  the  heat  of 
the  metal  plate. — Now  in  this  case,  the  abolition  of  common  sensation  was  not 
so  complete  as  in  the  former  instance;  but  of  the  peculiar  kind  of  impression, 
which  was  found  most  efficacious  in  exciting  reflex  movements,  no  consciousness 
whatever  was  experienced.  Not  less  interesting  was  the  circumstance,  that  con- 
vulsions could  be  readily  excited  by  impressions  on  surfaces  above  the  seat  of 
injury:  as,  by  pulling  the  hair  of  the  scalp,  a  sudden  noise,  and  so  on.  This 
proves  two  important  points  :  first,  that  a  lesion  of  the  cord  may  be  such  as  to 
intercept  the  transmission  of  voluntary  influence,  and  yet  may  allow  the  trans- 
mission of  that  reflected  from  incident  nerves.  Secondly,  that  all  influences 
from  impressions  on  incident  nerves  are  diffused  through  the  cord ;  for,  in  the 
instance  adduced,  the  reflected  influence  was  undoubtedly  not  made  to  deviate 
into  the  cord  by  the  morbid  condition  of  that  organ,  but  followed  its  natural 
course  of  diffusion,  being  rendered  manifest  in  this  case  by  the  convulsions  which 
were  excited,  in  consequence  of  increased  activity  of  the  motor  function  of  the 
cord-  It  is  further  interesting  to  remark,  that,  in  the  foregoing  case,  the  reflex 
actions  were  very  feeble  during  the  first  seven  days,  in  comparison  with  their 
subsequent  energy;  being  limited  to  slight  movements  of  the  feet,  which  could 
not  always  be  excited  by  tickling  the  soles.  (In  another  case  of  very  similar 
character,  it  was  three  days  after  the  accident,  before  any  reflex  actions  could  be 
produced.)  It  is  evident,  then,  that  the  spinal  cord  must  have  been  in  a  state 
of  concussion,  which  prevented  the  manifestation  of  its  peculiar  functions,  so 
long  as  this  effect  lasted  ;  and  it  is  easy,  therefore,  to  perceive,  that  a  still  more 
severe  shock  might  permanently  destroy  its  power,  so  as  to  prevent  the  exhibi- 
bition  of  any  of  the  phenomena  of  reflex  action. 

509.  So  many  cases  of  this  kind  have  now  occurred,  that  it  may  be  considered 
as  a  demonstrated  fact,  that  the  Spinal  Cord,  or  insulated  portions  of  it,  may  serve 
in  Man,  no  less  than  in  the  lower  animals,  as  the  centre  of  very  energetic  reflex 
actions,  when  the  Encephalic  power  which  ordinarily  operates  through  it  is  sus- 
pended or  destroyed,  or  when  it  is  prevented  from  influencing  the  Spinal  nerves 
by  such  an  injury  to  the  Cord  above  their  points  of  connection  with  it,  as  prevents 
the  transmission  of  nervous  polarity :  and  it  is  further  evident  that  these  move- 
ments are  not  more  dependent  upon  Sensation,  than  they  are  upon  the  Will, 
since  they  may  be  excited  without  the  consciousness  of  the  individual,  even  when 
this  is  fully  directed  to  the  part.1  And  we  thus  have  adequate  ground  for  the 
assertion,  that  the  movements  which  may  be  called-forth  by  stimulation  in  the 
states  of  profound  Sleep  or  Coma,  are  not  to  be  held  to  indicate  that  sensation  is 
even  momentarily  excited ;  since  we  know  that  the  reflex  power  of  the  Spinal 
Cord  may  be  called  into  action  by  impressions  which  do  not  travel  onwards  to 

1  The  Author  is  informed  by  his  friend  Mr.  Paget.  that  among  the  notes  left  by  John 
Hunter  (which  furnished  some  of  the  materials  for  the  admirable  Catalogue  of  the  Patho 
logical  portion  of  the  Hunterian  Museum  drawn-up  by  Mr.  Paget),  there  was  the  record 
of  a  case  of  paraplegia,  in  which  it  appeared  that  Hunter  had  witnessed  reflex  movements 
of  the  legs,  in  which  sensation  did  not  participate.  When  the  patient  was  asked  whether 
he  felt  the  irritation,  by  which  the  motions  were  excited,  he  significantly  replied — glancing 
at  his  limbs, — "  No,  Sir,  but  you  see  my  legs  do." 

31 


482  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

the  sensorium,  or  which  are  powerless  to  affect  the  consciousness  even  when  they 
arrive  there.  These  abnormal  reflex  actions  of  the  Spinal  Cord  of  Man,  though 
often  powerful,  have  much  less  regularity  and  apparent  purposivcness,  than  have 
the  movements  executed  by  the  lower  Vertebrata  (as  the  Frog,  §  505)  after  de- 
capitation or  section  of  the  cord ;  the  latter  approaching,  in  respect  to  these 
qualities,  to  the  reflex  movements  of  Articulated  animals.  It  must  not  hence  be 
inferred,  however,  that  there  is  any  essential  difference  in  the  endowments  of  the 
Spinal  Cord,  between  Man  and  the  lower  animals ;  or  that  any  psychical  agency 
exists  in  the  latter  case,  which  is  wanting  in  the  former.  We  have  already  seen 
that  the  existence  of  even  the  most  perfectly-adapted  combination  of  different 
muscular  actions,  all  obviously  bearing  upon  a  definite  object,  cannot  in  itself 
justify  our  attributing  this  combination  to  design  or  voluntary  choice  on  the  part 
of  the  organism  that  executes  it  (§  459);  whilst,  on  the  other  hand,  to  remove 
these  movements  in  any  case  from  the  category  of  automatic  actions,  would  be  to 
assign  to  the  Spinal  Cord  a  power  of  consciously  selecting  and  directing  them, 
such  as  we  have  every  reason  for  believing  to  be  limited  to  the  higher  parts  of  the 
Cerebro-Spinal  centres.  Now  the  very  uniformity  of  the  movements  in  question, 
is  itself  an  indication  that  they  do  not  proceed  from  any  purposive  choice,  but 
depend  upon  the  special  endowments  of  those  centres  of  reflex  action,  whence  the 
impulses  that  call  them  forth  immediately  issue  to  the  nerves;  and  hence  the 
more  marked  adaptiveness  of  the  reflex  actions  performed  by  many  of  the  lower 
tribes  of  animals,  can  only  be  held  to  indicate  that  a  larger  share  of  such  adapta- 
tion is  effected  in  them  by  what  may  be  termed  the  mechanism  of  their  nervous 
centres,  and  that  less  is  left  to  voluntary  choice  and  direction,  which  can  only  be 
safely  trusted  where  a  considerable  amount  of  intelligence  exists  to  guide  it; — 
a  conclusion  which  accords  well  with  what  has  been  already  stated,  respecting  the 
structural  differences  that  seem  to  exist  between  the  Spinal  Cord  of  Man,  and 
that  of  the  inferior  Vertebrata  (§  487). 

510.  The  endowments  of  the  Medulla  Oblongata  do  not  seem  to  differ  from 
those  of  the  Spinal   Cord  in  any  other  respect,  than  in  the  speciality  of  the 
reflex  movements  to  which  it  ministers.     This  part  of  the  Cranio-Spinal  Axis 
has  been  regarded  by  some  Physiologists,  indeed,  as  the  peculiar  seat  of  vitality ; 
since,  although  the  other  Encephalic  masses  may  be  withdrawn  from  above,  and 
nearly  the  whole  of  the  Spinal  Cord  may  be  removed  from  below,  without  the 
destruction  of  life,  yet  a  complete  stop  is  put  to  the  current  of  vital  action  when 
the  Medulla  Oblongata  is  destroyed.     But  the  dependence  of  the  vital  activity 
of  the  body  generally  upon  the  functional  integrity  of  this  part  of  the  nervous 
system,  is  simply  consequent  upon  the  fact,  that  the  Medulla  Oblongata  contains 
the  ganglionic  centre  of  the  Respiratory  movements ;  upon  the  continuance  of 
which,  as  already  shown  (Chap.  vii.  Sect.  3),  the  continuance  of  the  Circulation 
is  dependent,  and  with  this,  the  maintenance  of  the  Organic  functions  generally. 
It  is  also  the  ganglionic  centre  of  the  nerves  of  Deglutition  ;  the  abolition  of 
which  function  must  of  course  be  destructive  to  life,  though  less  speedily  than 
that  of  Respiration. 

511.  Hence  the  Spinal  Cord,  with  its  Encephalic  prolongation,  may  be  said 
to  supply,  by  its  'reflex  power/  the  conditions  requisite  for  the  maintenance  of 
the  various  muscular  movements  which  are  essential  to  the  continuance  of  the 
Organic  processes;  and,  as  Dr.  M.  Hall  has  pointed  out,  it  especially  governs 
the  various  orifices  of  ingress  and  egress. — Thus,  the  act  of  Deglutition  is  entirely 
dependent  upon  the  Spinal  Axis  and  the  nerves  proceeding  from  it;  the  Will 
being  in  no  other  way  concerned  in  it,  than  by  originating  the  necessary  stimu- 
lus ;  and  even  sensation  not  being  a  necessary  link  in  the  chain  of  excito-motor 
action  (§§  80 — 82).     The  action  of  the  cardiac  sphincter,  again,  —  and  probably 
that  of  the  pyloric  sphincter  also,  —  is  dependent  upon  its  nervous  connection 
svith  the  Spinal  Axis ;    and  is  entirely  regulated  without  sensorial  excitement 
(§  82)      And  there  is  much  reason  to  believe  that  certain  of  the  movements  of 


FUNCTIONS    OF    THE    SPINAL    CORD.  483 

the  Stomach  itself  are  in  like  manner  dependent  upon  its  connection  with  the 
Medulla  Oblongata  (§  84),  although  there  is  evidence  that  it  possesses  an  inde- 
pendent motor  activity  of  its  own.  The  movements  of  the  Intestinal  tube  are 
unquestionably  influenced  by  the  Spinal  Cord,  although  essentially  independent  of 
it  (§§  86,  87) ;  but  the  sphincter  which  surrounds  its*  orifice  of  egress  is  un- 
doubtedly placed  under  its  guardianship,  although  partly  subjected  (in  Man)  to 
the  control  of  the  Will.  The  same  may  be  said  of  the  ejcpuhor  muscles  con- 
cerned in  the  act  of  Defecation ;  and  of  the  expulsors  and  sphincter  which  effect 
and  control  the  act  of  Urination  (§  88).  —  Looking,  ag;iin,  at  the  movements 
which  are  subservient  to  the  Respiratory  process,  we  find  that  all  those  which  are 
essential  to  its  regular  maintenance  are  performed  through  the  intermediation  of 
the  Spinal  Axis  alone  j  that  the  Will  has  only  such  a  limited  power  over  them, 
as  to  bring  them  into  harmony  with  its  other  requirements,  as  in  the  acts  of 
vocalization  and  in  extraordinary  muscular  exertions j  and  that  the  stimulus  by 
which  they  are  commonly  maintained  does  not  even  afifect  the  consciousness,  the 
1  besoin  de  respirer '  only  becoming  sensible  when  the  respiratory  process  is  being 
imperfectly  performed  (§§  299 — 302).  Not  only  are  the  ordinary  respiratory 
movements  performed  through  this  channel,  but  the  aperture  of  the  Grlottis  is 
regulated  by  it,  in  everything  that  concerns  the  respiration ;  and  either  by  its 
spasmodic  closure  against  the  entrance  of  unfit  substances,  or  by  the  expulsor 
effort  of  coughing  which  is  excited  by  them  when  they  do  find  their  way  into 
the  air-passages,  these  passages  are  kept  free  from  solid,  liquid,  or  gaseous  par- 
ticles, whose  presence  in  them  would  be  injurious. — In  the  expulsion  of  the 
Generative  products,  also,  the  reflex  power  of  the  Spinal  Cord  takes  an  important 
share.  The  muscular  contractions  which  produce  the  Emissio  Seminis  are  excito- 
inotor  in  their  nature ;  being  independent  of  the  Will,  and  not  capable  of  re- 
straint by  it  when  once  fully  excited ;  and  being  (like  those  of  Deglutition)  ex- 
citable in  no  other  way  than  by  a  particular  local  irritation.  It  has  been  shown 
by  experiment,  and  also  by  pathological  observation,  that  the  separation  of  the 
lower  portion  of  the  Spinal  Cord  from  the  upper  does  not  prevent  these  move- 
ments from  being  excited,  although  the  act  is  then  unaccompanied  with  sensa- 
tion, which  proves  that  sensation  is  not  essential  to  its  performance;  on  the  other 
hand,  the  power  of  emission  is  annihilated  by  destruction  of  the  lower  .portion 
of  the  Spinal  Cord,  or  by  section  of  the  nerves  which  supply  the  genital  organs. 
The  act  of  Parturition,  however,  seems  to  be  less  dependent  upon  the  Spinal 
Cord  j  for,  as  will  be  shown  hereafter  (Chap,  xvi.,  Sect.  3),  the  contractions  of 
the  Uterus,  which  are  alone  sufficient  to  expel  the  foetus  when  there  is  no  con- 
siderable resistance,  are  not  to  be  regarded  as  '  reflex/  and  it  is  only  in  the  co- 
operation of  those  associated  muscles  which  come  into  play  in  the  second  stage 
of  labour,  when  the  head  is  passing  through  the  os  uteri  and  is  engaged  in  the 
pelvic  cavity,  that  the  assistance  of  the  Spinal  cord  and  its  nerves  is  called-in. 
These  movements,  like  those  of  Defecation,  may  be  to  a  certain  extent  promoted 
or  restrained  by  voluntary  effort ;  but  when  the  exciting  influence  (the  pressure 
of  the  head  against  the  parietes  of  the  vaginal  canal)  has  once  been  fully  brought 
into  operation  by  the  uterine  contractions,  the  Will  has  little  power  over  them, 
either  in  one  way  or  the  other.  The  antagonizing  influence  of  the  sphincter 
vaginae  seems,  like  that  of  the  sphincter  ani,  to  be  dependent  upon  the  Spinal 
Cord ;  and  thus  it  happens  that  when  its  tension  and  that  of  other  muscular 
parts  has  been  destroyed  by  death,  whilst  the  uterus  still  retains  its  contractility, 
the  power  of  the  latter  has  sufficed  for  the  completion  of  the  parturient  process, 
the  child  being  expelled  after  the  respiratory  movements  have  ceased. 

512.  The  Spinal  Axis  is  not  merely  the  instrument  whereby  the  movements 

essential  to  the  maintenance  of  the  Organic  functions  are  sustained ;  it  is  also 

subservient  to  other  muscular  actions,  whose  character  is  essentially  protective 

Thus  it  was  ascertained  by  Dr.  M.  Hall '  that,  if  the  functions  of  the  Brain  be 

1  «« Memoirs  on  the  Nervous  System,"  1837,  p.  61. 


484  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

suspended  or  destroyed,  without  injury  to  the  Spinal  Cord  and  its  nerves,  the 
Orbicularis  muscle  will  contract,  so  as  to  occasion  the  closure  of  the  eyelids,  upon 
their  tarsal  margin  being  touched  with  a  feather.  This  fact  is  interesting  in 
several  points  of  view.  In  the  first  place,  it  is  a  characteristic  example  of  an 
adaptive  action,  occurring  under  circumstances  in  which  volition  cannot  bo 
imagined  to  guide  it,  and  in  which  there  is  no  valid  reason  to  believe  that  sensa- 
tion directs  it.  Further,  it  explains  the  almost  irresistible  nature  of  the  ten- 
dency to  winking,  which  is  performed  at  short  intervals  by  the  contraction  of 
the  Orbicularis  muscle;  this  is  evidently  a  reflex  action,  capable  of  being  in 
some  degree  restrained  (like  that  of  respiration)  by  the  will,  but  only  until  such 
time  as  the  stimulus  (resulting  perhaps  from  the  collection  of  minute  particles 
of  dust  upon  the  eyes,  or  from  the  dryness  of  their  surface  in  consequence  of 
evaporation,)  becomes  too  strong  to  be  any  longer  resisted.  The  nervous  channel 
through  which  this  action  is  performed,  is  completed  by  the  first  branch  of  the 
Fifth  and  the  Portio  Dura  of  the  seventh.  Again,  we  have  in  sleep  or  in  apo- 
plexy an  example  of  this  purely  spinal  action,  unbalanced  by  the  influence  of  the 
will,  which,  in  the  waking  state,  antagonizes  it  by  calling  the  levator  palpebrse 
into  action.  As  soon  as  the  will  ceases  to  act,  the  lids  droop,  and  close  over  the 
eye  so  as  to  protect  it ;  and  if  those  of  a  sleeping  person  be  separated  by  the  hand, 
they  will  be  found  presently  to  return.  Here,  as  in  studying  the  respiratory  and 
other  movements,  we  are  led  to  perceive  that  it  is  the  Brain  alone  which  is  torpid 
during  sleep,  and  whose  functions  are  affected  by  this  torpidity.  As  Dr.  M.  Hall 
very  justly  remarks,  "the  Spinal  system  never  sleeps;"  it  is  constantly  in  ac- 
tivity; and  it  is  thus  that,  in  all  periods  and  phases  of  Life,  the  movements 
which  are  essential  to  its  continued  maintenance  are  kept-up  without  sensible 
effort. — The  closure  of  the  pupil  against  a  strong  light,  is  another  movement  of 
the  same  protective  tendency.  The  contraction  of  the  movement  is  immediately 
caused  by  the  Third  pair,  or  Motor  Oculi,  as  is  easily  shown  by  irritating  the 
trunk  of  that  nerve,  and  observing  the  result;  but  the  stimulus  which  excites  it 
is  conveyed  through  the  Optic  nerve.  Yet  although  the  contraction  of  the  pupil 
is  usually  in  close  accordance  with  the  sensation  occasioned  by  the  impression  of 
light  upon  the  retina,  yet  there  is  evidence  to  prove  that  the  sensation  of  light  is 
not  always  necessary ;  for  even  when  the  sight  of  both  eyes  has  been  entirely  de- 
stroyed by  amaurosis,  the  normal  actions  have  been  witnessed  in  the  pupil,  in 
accordance  with  the  varying  degree  of  light  impinging  on  the  retina.  Such  cases 
seem  to  indicate  that  the  motion  results  from  an  impression  upon  the  retina, 
which  impression  being  conducted  to  the  Sensorium,  ordinarily  produces  a  sen- 
sation; but  that  even  where  no  sensation  is  produced,  on  account  of  a  disordered 
state  of  the  part  of  the  ganglionic  centre  in  \\hich  the  Optic  nerve  terminates,  if 
the  central  tract  which  connects  that  nerve  with  the  Third  pair  retain  its  integ- 
rity, the  reflex  contraction  of  the  pupil  may  still  be  excited  through  it.  The  rarity 
of  the  occurrence  is  easily  accounted-for,  by  the  fact  that  in  most  cases  of  amau- 
rosis, the  disease  lies  in  the  retina  or  in  the  trunk  of  the  nerve,  and  thereby 
checks  both  its  spinal  and  its  encephalic  actions. — Although  we  are  not  at  present 
acquainted  with  any  similar  protective  movements,  in  the  Human  being,  designed 
to  keep  the  organ  of  Hearing  from  injury,  yet  there  can  be  little  doubt  that  those 
which  we  are  constantly  witnessing  in  other  animals,  possessed  of  large  external 
ears,  are  reflex  actions  excited  by  the  irritation  applied  to  them.  In  regard  to  the 
Nose,  we  find  a  remarkably  complex  action — that  of  Sneezing — adapted  to  drive- 
off  any  cause  of  irritation  (§  306).  The  stimulus  is  conveyed,  in  this  case,  not 
through  the  Olfactory  nerve,  but  through  the  Fifth  pair;  so  that  it  is  not  depen- 
dent upon  the  excitement  of  the  sensation  of  Smell.  The  act  of  Coughing,  also, 
may  be  regarded  as  of  a  protective  character ;  being  destined  to  remove  sources 
of  irritation  from  the  air-passages.  Many  of  the  automatic  movements  performed 
by  the  limbs  of  Frogs  and  other  animals,  when  their  connection  with  the  brain 
has  been  cut  off  (§  505),  appear  destined  to  remove  these  parts  from  sources 


FUNCTIONS    OF    THE    SPINAL    CORD.  485 

of  irritation  or  injury;  and  they  may  thus  be  rightly  placed  under  the  same 
category. 

513.  The  fact  that  Sensation  is  very  commonly  associated  with  the  reflex 
actions  wo  have  been  considering,  being  produced  by  the  impression  that  excites 
them,  has  led  many  to  suppose  that  it  necessarily  participates  in  them ; — a  doc- 
trine which  we  have  seen  to  be  untenable.     But  the*question  not  unnaturally 
arises,  why  Sensation  should  so  constantly  participate  in  these  operations,  if  nor, 
essential  to  them;  and  the  answer  to  this  question  is  to  be  found  in  the  fact,  that 
it  is  only  through  sensation  that  a  higher  set  of  actions,  mental  and  bodily,  is 
called  into  play,  which  is  essential  to  the  continued  maintenance  of  those  belong 
ing  to  the  present  category.     Illustrations  of  this  truth  might  be  drawn  from  any 
of  the  functions  already  noticed;  but  the  Ingestion  of  food  will  supply  us  with 
one  of  the  most  apposite.     We  have  seen  that  the  act  of  Deglutition  is  in  itself 
independent  of  sensation  ;  anything  that  comes  within  the  grasp  of  the  pharyn- 
geal  constrictors  being  conveyed  downwards  by  their  reflex  contraction,  just  as 
anything  which  touches  the  arms  of  a  Polype  is  entrapped  by  them  and  drawn 
into  the  stomach.     But  this  action  is  attended  with  sensation,  in  the  ordinary 
condition  of  the  higher  Animal,  apparently  in  order  that  guidance  may  be  thus 
afforded  in  the  performance  of  those  other  movements  of  prehension,  mastication, 
&c.,  by  which  the  food  may  be  brought  within  reach  of  the  apparatus  of  deglu- 
tition ;  and  the  sensations  which  are  linked  with  these,  are  among  the  influences 
which  prompt  to  those  higher  mental  operations,  whereby  food  is  provided  for 
the  digestive  apparatus  to  make  use  of.     The  Zoophyte  is  dependent  for  its  sup- 
plies of  aliment,   upon  what   the   currents  in  the   surrounding  fluid,  or  other 
chances,  may  bring  into  its  neighbourhood ;  and  if  these  should  fail,  it  starves. 
The  anencephalous  Infant,  again,  can  swallow,  and  even  suck;  but  it  can  execute 
no  other  movements  adapted  to  obtain  the  supply  of  food  continually  necessary 
for  its  maintenance,  because  it  has  not  a  mind  which  sensations  could  awake  into 
activity.     The  sensation  connected  with  excito-motor  actions  has  not  only  this 
important  end,  but  it  frequently  contributes  to  enjoyment,  as  in  Suction  and 
Ejaculatio  serninis.     The  sensation  accompanying  the  actions  of  this  class,  more- 
over, frequently  affords  premonition  of  danger,  or  gives  excitement  to  supplemen- 
tary actions  destined  to  remove  it,  as  in  the  case  of  Respiration  ;  for  where  any- 
thing interferes  with  the  due  discharge  of  the  function,  the  uneasy  sensation  that 
ensues  occasions  unwonted  movements,  which  are  more  or  less  adapted  to  remove 
the  impediment,  in  proportion  as  they  are  guided  by  judgment  as  well  as  by  con- 
sciousness.    Again,  sensation  often  gives  warning  against  inconvenience,  as  in 
the  Excretory  functions ;  and  here  it  is  very  evident,  that  its  purpose  is  not  only 
(if  it  be  at  all)  to  excite  the  associated  muscles  necessary  for  the  excretion,  but 
actually  to  make   the  Will  set  up  the  antagonizing  action  of  the  sphincters 
(88,  89). 

514.  We  have  now  to  inquire  how  far  the  independent  action  of  the  Spinal  Cord 
is  concerned  in  the  general  muscular  movements  of  Man,  and  especially  in  the  loco- 
motive actions  of  his  inferior  extremities.     On  this  point,  it  is  obvious  that  wo 
must  not  be  guided  by  the  analogy  of  the  lower  animals ;  since  the  locomotive 
and  other  movements  of  Man  are  for  the  most  part  volitional  and  purposive,  and 
he  has  to  acquire  by  experience  that  control  over  his  muscular  apparatus  which 
is  necessary  to  enable  him  to  perform  them ;  whilst  in  Invertebrata  generally, 
and  in  a  large  part  of  the  lower  Vertebrata,  it  is  evident  that  the  movements  of 
progression,  &c.,  which  are  characteristic  of  each  species,  come  under  the  general 
category  of  automatic  actions,  and  are  provided  for  in  the  original  organization 
of  its  nervous  centres,  being  performed  without  any  education,  and  under  circum- 
stances which   render  the  notion  of  a  purpose  on  the  Animal's  own  part  quite 
untenable.     In  so  far  as  these  instinctive  movements  require  the  guidance  and 
direction  of  sensations,  they  must  be  referred  to  the  'consensual'  group;  but 
clear  evidence  is  afforded  by  the  continuance  of  many  of  them  after  the  removal 


486  FUNCTIONS    OF   THE   CEREBRO-SPINAL    NERVOUS    SYSTEM. 

of  the  centres  of  sensation,  that  they  are  excito-motor  in  their  character,  and  that 
they  require  no  higher  centre,  than  the  ganglia  which  correspond  to  the  Spinal 
Cord  of  Man.1  There  can  be  little  doubt  that  the  habitual  movements  of  loco- 
motion, and  others  which  have  become  <  secondarily  automatic/  may  be  performed 
by  Man  (under  particular  circumstances)  through  the  agency  of  the  Spinal  Cord 
alone,  under  the  guidance  and  direction  of  the  Sensorial  centres,  or  even  without 
such  guidance;  the  required  condition  being,  that  the  influence  of  the  Cerebrum 
shall  be  entirely  withdrawn.  Thus,  numerous  instances  are  on  record,  in  which 
soldiers  have  continued  to  march  in  a  sound  sleep;  and  the  Author  has  been 
assured  by  an  intelligent  witness,  that  he  has  seen  a  very  accomplished  pianist 
complete  the  performance  of  a  piece  of  music  in  the  same  state.2  A  case  has  been 
mentioned  to  him  by  his  friend,  Dr.  William  Budd,  of  a  patient  labouring  under 
that  form  of  epilepsy  in  which  there  was  simply  a  temporary  suspension  of  con- 
sciousness without  convulsion,  who,  whenever  the  paroxysm  eame-on,  persisted  in 
the  kind  of  movement  in  which  he  was  engaged  at  the  moment;  and  thus  on  one 
occasion  fell  into  the  water  through  continuing  to  walk  onwards,  and  frequently 
(being  a  shoemaker  by  trade)  wounded  his  fingers  with  the  awl  in  his  hand,  by  a 
repetition  of  the  movement  by  which  he  was  endeavouring  to  pierce  the  leather. 
Such  facts  as  these  add  great  strength  to  the  probability,  that  when  the  Cerebral 
power  is  not  suspended,  but  merely  directed  into  another  channel,  as  in  the  states 
of  Reverie  or  Abstraction,  and  the  attention  is  entirely  drawn-off  from  the  move- 
ments of  locomotion,  the  continuance  of  these  is  due  to  the  independent  auto- 
matic action  of  the  Spinal  Cord,  the  direction  being  given  to  them  by  the  Sen- 
sory Ganglia.  This  point,  however,  will  be  more  fully  considered  hereafter 
(§  540) ;  at  present  it  may  be  remarked,  that,  when  a  regular  train  of  movements 
is  being  performed  under  such  conditions,  every  single  action  may  be  probably 
regarded  as  affording  the  stimulus  to  the  next;  each  contact  of  the  foot  with  the 
ground,  in  the  act  of  walking,  exciting  the  muscular  contractions  which  consti- 
tute the  next  step;3  and  each  movement  of  the  musician  prompting  that  which 
has  customarily  followed  it,  after  the  same  fashion. 

515.  Now  in  all  these  cases,  it  seems  reasonable  to  infer,  that  the  same  kind 
of  connection  between  the  excitor  and  motor  nerves  comes  to  be  formed  by  a 
process  of  gradual  development,  as  originally  exists  in  the  nervous  systems  of 
those  animals  whose  movements  are  entirely  automatic;  this  portion  of  the  nervous 
system  of  Man  being  so  constituted,  as  to  grow-to  the  mode  in  which  it  is 
habitually  called  into  play.  Such  an  idea  is  supported  by  all  that  we  know  of 
the  formation  and  persistence  of  habits  of  nervo-muscular  action.  For  it  is  a 
matter  of  universal  experience,  that  such  habits  are  far  more  readily  acquired 
during  the  periods  of  infancy,  childhood,  and  youth,  than  they  are  after  the 
attainment  of  adult  age;  and  that,  the  earlier  they  are  acquired,  the  more 
tenaciously  are  they  retained.  Now  it  is  whilst  the  organism  is  growing  most 
rapidly,  and  the  greatest  amount  of  new  tissue  is  consequently  being  formed, 
that  we  should  expect  such  new  connections  to  be  most  readily  established ;  and, 
it  is  then,  too,  that  the  assimilative  processes  most  readily  take-on  that  new  mode 
of  action  (§  346),  which  often  becomes  so  completely  a  '  second  nature,'  as  to 
keep-up  a  certain  acquired  mode  of  nutrition  through  the  whole  subsequent  life. 

1  See  "Princ.  of  Comp.  Phys.,"  Am.  Ed.,  \\  649-654. 

a  In  playing  by  memory  on  a  musical  instrument,  the  muscular  sense  often  suggests  the 
sequence  of  movements  with  more  certainty  than  the  auditory ;  and  since  the  impressions 
derived  from  the  muscles  may  prompt  and  regulate  successional  movements,  without 
affecting  the  consciousness,  there  is  no  such  improbability  in  the  above  statements  as  might 
at  first  sight  appear. 

3  The  truth  of  this  view  seems  to  the  Author  to  be  strongly  supported  by  observation  of 
the  mode  in  which  Infants  learn  to  walk  ;  for  it  may  often  be  observed  that  long  before 
they  can  stand,  they  will  instinctively  perform  the  movements  of  walking,  if  they  be  so 
supported  that  the  feet  touch  the  ground. 


FUNCTIONS    OF    THE    SPINAL    CORD.  487 

It  is  an  additional  and  most  important  confirmation  of  this  view,  to  find  that 
when  a  nerve-trunk  has  been  cut-across,  the  re-establishment  of  its  conductive 
power  which  takes-place  after  a  certain  interval,  is  not  effected  by  the  re-union 
of  the  divided  fibres,  but  by  the  development  of  a  new  set  of  peripheral  fibres  in 
the  place  of  the  old  ones  (which  undergo  a  gradual  degeneration),  this  develop- 
ment proceeding  from  the  point  of  section,  and  th£  central  fibres  remaining 
unaltered.' — That  an  actual  continuity  of  nerve-fibres,  however,  is  not  requisite 
for  the  establishment  of  those  connections  between  excitor  and  motor  nerves,  in 
which  the  central  organs  take  part,  seems  probable  from  the  fact,  that  under 
particular  circumstances  we  find  the  influence  of  such  impressions  radiating  in 
every  direction,  and  extending  to  nerves  which  they  do  not  ordinarily  affect 
(Sect.  8).  Still  there  can  be  no  doubt  that  the  nerve-force  is  disposed  to  pass 
in  special  tracks  ;  and  it  seems  probable  that  whilst  some  of  these  are  originally 
marked-out  for  the  automatic  movements,  others  may  be  gradually  worn-in  (so  to 
speak)  by  the  habitual  action  of  the  Will ;  and  that  thus,  when  a  train  of 
sequential  actions  primarily  directed  by  the  Will  has  been  once  set  in  operation, 
it  may  continue  without  any  further  influence  from  that  source. 

516.  Another  manifestation  of  the  independent  power  of  the  Spinal  Cord,  is 
seen  in  its  influence  on  Muscular  Tension. — The  various  muscles  of  the  body, 
even  when  there  is  the  most  complete  absence  of  effort,  maintain  in  the  healthy 
state  of  the  system,  a  certain  degree  of  firmness,  by  their  antagonism  with  each 
other  ;  and  if  any  set  of  muscles  be  completely  paralyzed,  the  opposing  muscles 
will  draw  the  part  on  which  they  act,  out  of  its  position  of  repose ;  as  is  well 
seen  in  the  distortion  of  the  face  which  is  characteristic  of  paralysis  of  the  facial 
nerve  on  one  side.  This  condition  has  been  designated  as  the  tone  of  the  Mus- 
cles; but  this  term  renders  it  liable  to  be  confounded  with  their  tonic  contraction, 
which  is  also  concerned  in  maintaining  their  firmness,  but  which  is  a  manifesta- 
tion of  the  simple  contractility  of  their  tissue,  and  is  exhibited  alike  by  the  striated 
and  the  non-striated  forms  of  muscular  fibre,  but  more  especially  by  the  latter. 
(See  PRINC.  OF  GEN.  PHYS.,  AM.  ED.)  On  the  other  hand,  the  condition  now 
alluded-to,  which  may  perhaps  be  appropriately  termed  their  tension,  is  the  result 
of  a  moderate  though  continued  excitement  of  that  contractility,  through  the 
nervous  centres.  It  has  been  proved  by  Dr.  M.  Hall,  that  the  Muscular  Tension 
is  dependent,  not  upon  the  influence  of  the  Brain,  but  upon  that  of  the  Spinal 
Cord  ;  as  the  following  experiments  demonstrate. — "  Two  Rabbits  were  taken  ; 
from  one  the  head  was  removed ;  from  the  other  also  the  head  was  removed,  and 
the  spinal  marrow  was  cautiously  destroyed  with  a  sharp  instrument ;  the  limbs 
of  the  former  retained  a  certain  degree  of  firmness  and  elasticity ;  those  of  the 
second  were  perfectly  lax/'  Again  :  "  The  limbs  and  tail  of  a  decapitated  Turtle 
possessed  a  certain  degree  of  firmness  or  tone,  recoiled  on  being  drawn  from  their 
position,  and  moved  with  energy  on  the  application  of  a  stimulus.  On  with- 
drawing the  spinal  marrow  gently  out  of  its  canal,  all  these  phenomena  ceased. 
The  limbs  were  no  longer  obedient  to  stimuli,  and  became  perfectly  flaccid,  having 
lost  all  their  resilience.  The  sphincter  lost  its  circular  form  and  contracted  state, 
becoming  lax,  flaccid,  and  shapeless.  The  tail  was  flaccid,  and  unmoved  on  the 
application  of  stimuli." 2  It  is  further  remarked  by  Messrs.  Todd  and  Bowman, 
that  "a  decapitated  frog  will  continue  in  the  sitting  posture  through  the  influ 
ence  of  the  spinal  cord;  but  immediately  this  organ  is  removed,  the  limbs  fall 
apart." — This  operation  of  the  Spinal  Cord  is  doubtless  but  a  peculiar  manifesta- 
tion of  its  ordinary  reflex  function.  We  shall  hereafter  see  (§  541)  how  much  the 
influence  of  the  Will  in  producing  the  active  contraction  of  a  muscle,  is  depen- 
dent upon  sensations  received  from  it;  and  it  seems  highly  probable,  that  the 
impression  of  the  state  of  the  muscle,  conveyed  by  the  afferent  fibres  proceeding 

1  See  Dr.  Waller's  important  researches  on  the  Reproduction  of  Nervous  Substance,  in 
"  Mullet's  Archiv.,"  1852,  heft  iv. 
>  "See  Memoirs  on  the  Nervous  System,"  1837,  p.  93. 


488  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

from  it  to  the  spinal  cord,  is  sufficient  to  excite  this  state  of  moderate  tension 
through  the  motor  nerves  arising  from  the  latter.  Such  a  view  derives  proba- 
bility from  the  fact,  which  must  have  fallen  under  the  observation  of  almost 
every  one,  that  most  reflex  actions  become  increased"  in  energy,  if  resistance  be 
made  to  them.  Of  this  we  have  familiar  examples  in  the  action  of  the  expulsor 
muscles,  which  operate  in  defecation,  urination,  and  parturition,  if,  when  they  are 
strongly  excited,  their  efforts  be  opposed  by  spasmodic  contraction  of  the  sphinc- 
ters, or  by  mechanical  means.  Many  forms  of  convulsive  movement  exhibit  the 
same  tendency,  their  violence  being  proportional  to  the  mechanical  force  used  to 
restrain  them.1  Here  it  is  evident  that  the  impression  of  resistance,  conveyed  to 
the  Spinal  Cord,  is  the  source  of  the  increased  energy  of  its  motor  influence ;  from 
which  we  may  fairly  infer  that  the  moderate  resistance,  occasioned  by  the  natu- 
ral antagonism  of  the  muscles,  is  the  source  of  their  continued  and  moderate 
tension,  whilst  they  are  under  the  influence  of  the  Spinal  Cord.  This  constant 
though  gentle  action  serves  to  keep-up  the  nutrition  of  the  muscles,  which  are 
paralyzed  to  the  will ;  and  this  is  still  more  completely  maintained,  if  the  portion 
of  the  nervous  centres,  with  which  they  remain  connected,  be  so  unduly  irritable, 
that  the  muscles  are  called  into  contraction  upon  the  slightest  excitation,  and  are 
thus  continually  exhibiting  twitchings,  starlings,  or  more  powerful  convulsive 
movements.  It  is  upon  the  continuance  of  the  nutrition  of  the  muscles,  that  the 
persistence  of  their  contractility  depends ;  and  hence  the  Spinal  Cord  has  an 
indirect  influence  upon  this  peculiar  property,  which  is  more  likely  to  be  retained, 
when  the  muscle  is  still  subject  to  the  influence  of  the  Spinal  Cord,  though  cut- 
off from  that  of  the  Brain,  than  when  it  is  completely  paralyzed  by  the  entire 
separation  of  its  connection  with  the  nervous  centres. 

3.    Of  the  Sensory  Ganglia  and  their  Functions. —  Consensual  Movements. 

517.  At  the  base  of  the  Brain  in  Man,  concealed  by  the  Cerebral  Hemispheres, 
but  still  readily  distinguishable  from  them,  we  find  a  series  of  ganglionic  masses; 
which  are  in  direct  connection  with  the  nerves  of  Sensation ;  and  which  appeal 
to  have  functions  quite  independent  of  those  of  the  other  components  of  the 
Encephalon. — Thus  anteriorly  we  have  the  Olfactive  ganglia,  in  what  are  com- 
monly termed  the  '  bulbous  expansions  of  the  Olfactive  nerve/  That  these  are 
real  ganglia,  is  proved  by  their  containing  grey  or  vesicular  substance;  and  their 
separation  from  the  general  mass  of  the  Encephalon,  by  the  peduncles  or  foot- 
stalks commonly  termed  the  'trunks'  of  the  Olfactory  nerves,  finds  its  analogy 
in  many  species  of  Fish.  The  ganglionic  nature,  of  these  masses  is  more  evident 
in  many  of  the  lower  Mammalia,  in  which  the  organ  of  Smell  is  highly  developed, 
than  it  is  in  Man,  whose  olfactive  powers  are  comparatively  moderate.  At  some 
distance  behind  these,  we  have  the  representatives  of  the  Optic  ganglia,  in  the 
Tubercula  Quadrigemina,  to  which  the  principal  part  of  the  roots  of  the  Optic 
nerve  may  be  traced.  Although  these  bodies  are  so  small  in  Man,  in  comparison 
with  the  whole  Encephalic  mass,  as  to  be  apparently  insignificant,  yet  they  are 
much  larger,  and  form  a  more  evidently-important  part  of  it,  in  many  of  the 
lower  Mammalia;  though  still  presenting  the  same  general  aspect. — The  Audi- 
tory ganglia  do  not  form  distinct  lobes  or  projections;  but  are  lodged  in  the 
substance  of  the  Medulla  Oblongata.  Their  real  character  is  most  evident  in 
certain  Fishes,  as  the  Carp;  in  which  we  trace  the  Auditory  nerve  into  a  gan- 
glionic centre  as  distinct  as  the  Optic  ganglion.  In  higher  animals,  however, 
and  in  Man,  we  are  able  to  trace  the  Auditory  nerve  into  a  small  mass  of  vesi- 
cular matter,  which  lies  on  each  side  of  the  Fourth  Ventricle;  and  although 
this  if*  lodged  in  the  midst  of  parts  whose  function  is  altogether  different,  yet 

1  Hence  the  absurdity  of  the  common  practice  of  endeavouring  to  prevent  the  move- 
fnents  of  the  limbs  and  body,  in  Convulsive  paroxysms,  by  mechanical  constraint.  Nothing 
ehould  be  attempted,  but  what  is  requisite  to  guard  the  sufferer  from  doing  himself  an. 
jujury. 


SENSORY     GANGLIA.  489 

there  seems  no  reason  for  doubting  that  it  has  a  character  of  its  own,  and  that 
it  is  really  the  ganglionic  centre  of  the  Auditory  nerve. — In  like  manner,  we 
may  probably  fix  upon  a  collection  of  vesicular  matter,  imbedded  in  the  Medulla 
Oblongata, — which  is  considered  by  Stilling  to  be  the  nucleus  of  the  Glosso- 
pharyngeal  nerve,  and  to  which  a  portion  of  the  sensory  root  of  the  Fifth  pair 
may  be  also  traced, — as  representing  the  Gustatory  ganglion. 

518.  At  the  base  of  the  Cerebral  Hemispheres,  we  find  two  other  large  gan- 
glionic masses,  on  either  side ;  through  which  nearly  all  the  fibres  appear  to  pass 
that  connect  the  Hemispheres  with  the  Medulla  Oblongata:  namely,  the  Tha- 
lami  Optici,  and  the  Corpora  Striata  (Fig.  142).  Now,  although  these  arti 

[Fia.  142. 


Section  of  tne  cerebrum,  displaying  the  surfaces  of  the  corpora  striata,  and  optic  thalaml, 
the  cavity  of  the  third  ventricle,  and  the  upper  surface  of  the  cerebellum.— a  e.  Corpora 
quadrigemina,—  a  testis,  e  nates.  6.  Soft  commissure,  c  Carpus  callosum.  /.  Anterior  pil- 
lars of  fornix.  g.  Anterior  cornu  of  lateral  ventricle,  k  k.  Corpora  striata.  1 1.  Optic  tha- 
lami.  *  Anterior  tubercle  of  the  left  thalamus.  z  to  *.  Third  ventricle.  In  front  of  z, 
anterior  commissure,  b.  Soft  commissure.  *.  Posterior  commissure,  p.  Pineal  gland  with 
its  peduncles,  n  n.  Processus  a  cerebello  ad  testes.  m  ro.  Hemispheres  of  the  cerebellum. 
h.  Superior  vermiform  process,  t.  Notch  behind  the  cerebellum.] 

commonly  regarded  in  the  light  of  appendages  merely  to  the  Cerebral  Hemis- 
pheres, it  is  evident  from  the  large  quantity  of  vesicular  matter  they  contain, 
that  they  must  rank  as  independent  ganglionic  centres;  and  this  view  is  sup- 
ported alike  by  the  evidence  of  Comparative  Anatomy,  and  by  that  afforded  by 
the  history  of  Development.  For  it  is  certain  that  the  size  of  the  Thalami 
Optici  and  Corpora  Striata  presents  no  more  relation,  in  different  tribes  of  ani- 
mals, to  that  of  the  Cerebrum,  than  does  that  of  the  ganglia  of  Special  Sense ; 
and  they  may  even  present  a  considerable  development,  when  the  condition  of 
the  Cerebrum  is  quite  rudimentary.  Thus  in  the  Osseous  Fishes,  a  careful 
examination  of  the  relations  of  the  body  which  is  known  as  the  Optic  lobe  (Fig 
125,  c)  makes  it  apparent  that  this  is  the  representative,  not  merely  of  the  proper 


490  FUNCTIONS   0$    THE   CEREBRO-SPINAL   NERVOUS    SYSTEM. 

Optic  ganglion  of  Man,  but  also  of  the  Thalamus  Opticus ;  whilst,  again,  the 
mass  which  is  designated  as  the  Cerebral  lobe  (B)  is  chiefly  homologous  with  the 
Corpus  Striatum  of  higher  animals.  The  nature  of  the  latter  body  is  made 
apparent,  in  the  higher  Cartilaginous  Fishes,  by  the  presence  of  a  ventricle  in  its 
interior;  the  floor  of  this  cavity  being  formed  by  the  Corpus  Striatum,  whilst 
the  thin  layer  of  nervous  matter  which  forms  its  roof  is  the  only  representative 
of  the  Cerebral  hemisphere.  So  in  the  Human  embryo  of  the  6th  week,  we  find 
a  distinct  vesicle  for  the  Thalami  Optici,  interposed  between  the  vesicle  of  th-e 
Corpora  Quadrigemina  and  that  which  gives  origin  to  the  Cerebral  Hemispheres ; 
whilst  the  Corpora  Striata  constitute  the  floor  of  the  cavity  or  ventricle  which 
exists  in  the  latter,  this  being  as  yet  of  comparatively  small  dimensions. — Now, 
as  already  pointed-out  (§  490),  we  may  distinguish  in  the  Medulla  Oblongata  and 
Crura  Cerebri,  a  sensory  and  a  motor  tract;  by  the  endowments  of  the  nerves 
which  issue  from  them.  The  sensory  tract  may  be  traced  upwards,  until  it  almost 
entirely  spreads  itself  through  the  substance  of  the  Thalamus.  Moreover,  the  Optic 
nerves,  and  the  peduncles  of  the  Olfaetive,  may  be  shown  to  have  a  distinct  con- 
nection with  the  Thalami ;  the  former  by  the  direct  passage  of  a  portion  of  their 
roots  into  these  ganglia;  and  the  latter  through  the  medium  of  the  Fornix. 
Hence  we  may  fairly  regard  the  Thalami  Optici  as  the  chief  focus  of  the  Sen- 
sory nerves,  and  more  especially  as  the  ganglionic  centre  of  the  nerves  of 
common  sensation,  which  ascend  to  it  from  the  Medulla  Oblongata  and  Spinal 
Cord. — On  the  other  hand,  the  Corpora  Striata  are  implanted  on  the  Motor  tract 
of  th*e  Crura  Cerebri,  which  descend  into  the  Pyramidal  columns;  and  their  rela- 
tion to  the  fibres  of  which  that  tract  is  composed,  appears  to  be  essentially  the 
same  as  that  which  the  Thalami  bear  to  the  sensory  tract. — The  Corpora  Striata 
are  connected  with  each  other,  on  the  median  plane,  by  the  an t erior  commissure; 
and  the  Thalami  Optici,  by  the  soft  and  the  posterior  commissures.  The  Corpus 
Striatum  and  Thalamus  Opticus  of  the  same  side  are  very  closely  connected  by 
commissural  fibres,  stretching  from  one  to  the  other;  and,  if  the  preceding 
account  of  the  respective  offices  of  these  bodies  be  correct,  they  may  be  regarded 
as  having  much  the  same  relation  to  each  other,  as  that  which  exists  between 
the  posterior  and  anterior  peaks  of  vesicular  matter  in  the  Spinal  Cord ;'  the 
latter  issuing  motor  impulses,  in  respondence  to  sensations  excited  through  the 
former.  They  are  also  intimately  connected  with  other  ganglionic  masses  in 
their  neighbourhood,  such  as  the  '  locus  niger/  and  the  vesicular  matter  of  the 
1  tuber  annulare  ;'  which,  again,  are  in  close  relation  with  the  vesicular  matter  of 
the  Medulla  Oblongata. 

519.  It  has  been  commonly  supposed  that  the  fibres  of  the  Crura  Cerebri,  after 
entering  the  Corpora  Striata  and  Thalami  Optici,  pass  continuously  through  these 
bodies  receiving  'reinforcements'  of  additional  fibres  from  their  ganglionie  mat- 
ter ;  and  that  they  then  radiate  to  the  internal  surface  of  the  grey  matter  of  the 
Cerebral  Hemispheres.  Such  would  certainly  be  the  conclusion,  to  which  a 
superficial  examination  of  their  course  would  lead.  But  very  strong  reasons 
have  recently  been  advanced  for  the  belief,  that  the  fibres  of  the  Crura  Cerebri 
for  the  most  part,  if  not  entirely,  terminate  in  the  vesicular  substance  of  the 
Corpora  Striata  and  Thalami  Optici ;  and  that  the  radiating  fibres  of  the  Hemis- 
pheres take  a  fresh  departure  from  these  ganglia,  serving,  in  fact,  the  part  of 
commissures  to  connect  their  vesicular  substance  with  that  of  the  Cerebral 
ganglia.2  And  this  view,  as  we  shall  hereafter  see,  is  in  complete  accordance 
with  the  existence  of  a  very  decided  physiological  separation  between  these  two 
Bets  of  organs. — Altogether  it  is  very  evident,  that  a  series  of  true  ganglionic 
centres  exists  at  the  base  of  the  Encephalon,  which  are  really  as  distinct  from 

1  This  was  first  pointed-out  by  Messrs.  Todd  and  Bowman,  in  their  «« Physiological 
Anatomy,"  p.  251,  Am.  Ed. 

8  See  especially  Messrs.  Todd  and  Bowman's  "  Physiological  Anatomy,"  p.  308,  Am. 
Ed. ;  and  Prof.  Kolliker's  "  Mikroskopische  Anatomie,"  band  ii.,  §  118. 


491 

either  the  Cerebrum  or  Cerebellum,  as  the  latter  are  from  each  other ;  and  as 
these  centres  are  in  immediate  connection  with  the  nerves  both  of  special  and  of 
general  Sense,  they  may  be  appropriately  designated  the  Sensory  Ganglia.  An 
inquiry  into  the  distribution  and  endowments  of  their  nerves,  will  assist  us 
in  the  determination  of  the  functions  of  the  central  organs  in  which  they 
terminate. 

520.  Nerves  of  Special  Sense. — Through  the  First  pair,  or  Olfactory  nerve, 
are  transmitted  the  impressions  made  by  odorous  emanations  upon  the  surface  it 
supplies ;  and  it  is  not  susceptible  to  impressions  of  any  other  kind.     Anatomical 
examination  of  the  distribution  of  this  nerve  proves  that  it  is  not  one  which 
directly  conveys  motor  influence  to  any  muscles,  since  all  its  branches  are  dis- 
tributed to  the  membrane  lining  the  nasal  cavity ;  and  experimental  inquiry  leads 
to  the  same  result,  for  no  irritation  of  the  peduncles  or  branches  excites  any  mus- 
cular movement.     Further,  no  irritation  of  any  part  of  this  nerve  excites  reflex 
actions  through  other  nerves ;  again,  it  is  not  a  nerve  of  '  common'  sensation;  for 
animals  exhibit  no  signs  of  pain,  when  it  is  subjected  to  any  kind  of  irritation. 
Neither  the  division  of  the  nerve,  nor  the  destruction  of  the  olfactive  ganglia,  seems 
to  inconvenience  them  materially.     They  take  their  food,  move  with  their  accus- 
tomed agility,  and  exhibit  the  usual  appetites  of  their  kind.     The  f common' 
Sensibility  of  the  parts  contained  in  the  olfactive  organ  is  in  no  degree  impaired, 
as  is  shown  by  the  effect  of  irritating  vapours ;  but  the  animals  are  destitute  of 
the  sense  of  smell,  as  is  shown  by  the  way  in  which  these  vapours  affect  them  ; 
for  at  first  they  appear  indifferent  to  their  presence,  and  then  suddenly  and 
vehemently  avoid  them,  as  soon  as  the  Schneiderian  membrane  becomes  irritated. 
Moreover  if  two  dogs,  with  the  eyes  bandaged,  one  having  the  olfactory  nerves 
and  ganglia  sound,  and  the  other  having  had  them  destroyed,  are  brought  into 
the  neighbourhood  of  the  dead  body  of  an  animal,  the  former  will  examine  it  by 
its  smell ;  whilst  the  latter,  even  if  he  touches  it  pays  no  attention  to  it.     This 
experiment  Valentin '  states  that  he  has  repeated  several  times,  and  always  with 
the  same  results.     Further,  common  observation  shows  that  sensibility  to  irri- 
tants, such  as  snuff,  and  acuteness  of  smell,  bear  no  constant  proportion  to  one 
another;  and  there  is  ample  pathological  evidence,  that  the  want  of  this  sense  is 
connected  with  some  morbid  condition  of  the  olfactory  nerves  or  ganglia.     It  is 
well  known   that  Magendie  has   maintained,  that  the  Fifth  pair  in  some  way 
furnishes  conditions  requisite  for  the  exercise  of  the  power  of  smell ;  asserting 
that,  when  it  is  cut,  the  animal  is  deprived  of  this  sense.     But  his  experiments 
were  made  with  irritating  vapours,  which  excite  sternutation  or  other  violent 
muscular  actions,  not  through  the  Olfactory  nerve,  but  through  the  Fifth  pair; 
and  the  experiments  of  Valentin,  just  related,  fully  prove  that  the  animals  are 
not  sensitive  to  odours,  strictly  so  called,  after  the  Olfactory  nerve  has  been 
divided.     The  acuteness  of  the  true  sense  of  smell  is  lessened  by  section  of  the 
Fifth  pair ;  but  this  is  because  the  Schneiderian  membrane  is  then  no  longer 
duly  moistened  by  its  proper  secretion,  and,  when  dry,  it  is  less  susceptible  of  the 
impressions  made  by  those  minute  particles  of  odoriferous  substances,  to  which 
the  excitement  of  the  sensation  must  be  referred. 

521.  That  the  Second  pair,  or  Optic  nerve,  has  an  analogous  character,  ap- 
pears alike  from  anatomical  and  experimental  evidence  (Fig.  143).    No  chemical 
or  mechanical  stimulus  of  the  trunk  produces  direct  muscular  motion ;  nor  does 
it  give  rise,  so  far  as  can  be  ascertained,  to  indications  of  pain ;  whence  it  may 
be  concluded,  that  this  nerve  is  not  one  of  '  common '  sensation.     That  the  ordi- 
nary sensibility  of  the  eyeball  remains,  when  the  functions  of  the  Optic  nerve 
are  completely  destroyed,  is  well  known ;  as  is  also  the  fact,  that  divisions  of.  it 
puts  an  end   to  the  power  of  vision.     Valentin   states  that  although  the  Optic 
nerve  may,  like  other  nerves,  be  in  appearance  completely  regenerated,  he  has 
never  been  able  to  obtain  any  evidence  that  the  power  of  sight  has  been  in  tlie 

1  "De  Functionibus  Nervorum  Cerebralium,"  &c.,  Bernse,  1839. 


492 


FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 


[FiG.  143. 


least  degree  recovered.     He  remarks  that  animals  suddenly  made  blind  exhibit 

great  mental  disturbance,  and  perform  many 
unaccustomed  movements ;  and  that  the  com- 
plete absence  of  the  power  of  vision  is  easily 
ascertained.  Morbid  changes  are  sometimes 
observed  to  take  place  in  eyes,  whose  Optic 
nerve  has  been  divided ;  but  these  are  by  no 
means  so  constant  or  so  extensive,  as  when 
the  Fifth  pair  is  paralyzed ;  and  they  may  not 
improbably  be  attributed  to  the  injury  occa- 
sioned by  the  operation  itself,  to  the  parts 
within  the  orbit. 

522.  The  Optic  nerve,  though  analogous 
to  the  Olfactory  in  all  the  points  hitherto 
mentioned,  differs  from  it  in  one  important 
respect; — that  it  has  the  power  of  conveying 
impressions  which  excite  reflex  muscular  mo- 
tions. This  is  especially  the  case  in  regard 
to  the  Iris,  the  ordinary  actions  of  which  are 
regulated  by  the  degree  of  light  impinging 
on  the  retina.  When  the  Optic  nerve  is  di- 
vided, contraction  of  the  pupil  takes  place ; 
A  view  of  the  2d  pah- or  optic,  and  the  but  this  does  not  occur,  if  the  connection  of 
origins  of  seven  other  pairs.  1,  1.  Globe  this  nerve  with  the  third  pair,  through  the 
of  the  eye;  the  one  on  the  left  hand  is  nervous  centres,  be  in  any  way  interrupted, 
perfect,  but  that  on  the  right  has  the  sole-  ^fter  such  division  (if  complete),  the  state 
rotic  and  choroid  removed  to  show  the  re-  f  h  u  j  t  ff  t  d  fe  variations  in 

tina.     2.  The  chiasm  of  the  optic  nerves.     ,         ,    *  »    ,.    ,        .        .      .J 

3.  The  corpora  albicantia.  4.  The  infun-  the  degree  °f  hSht  impinging  Oil  the  re- 
dibulum.  5.  The  Pons  Varolii.  6.  The  tma ;  except  in  particular  cases,  in  which  it 
medulla  oblongata.  The  figure  is  on  the  is  influenced  through  other  channels.  Thus, 
right  corpus  pyramidale.  7.  The  3d  pair,  jn  a  patient  suffering  under  amaurosis  of  one 

motores  oculi.     8.  4th  pair,  pathetic.     9.  the  y    of    the    affected    eye    is    often 

5th  pair,  trieremmi.     10.  6th  pair,  abdu-    />         -\   ,  •  •  j  -,v    ,r    . 

centes.     11.  f  th  pair,  auditory  and  facial.   f°Und  t0  Vai7  m  »ze»  in  accordance  With  that 

12.  8th  pair,  pneuraogastric,  spinal  acces-  °f  ™e  other  eye ;  but  this  eftect  is  due  to  the 
sory,  and  glosso-pharyngeal.  13.  9th  action  of  li^ht  on  the  retina  of  the  sound  eye, 
pair,  hypoglossal.]  which  produces  a  motor  change  in  the  third 

pair  on  both  sides.     Further,  as  already  shown 

(§  512),  the  impression  only  of  light  upon  the  retina  may  give  rise  to  contraction 
of  the  pupil,  by  reflex  action,  when  the  optic  nerve  is  itself  sound;  whilst  no 
sensations  are  received  through  the  eye,  in  consequence  of  disease  in  the  senso- 
rial  portion  of  the  nervous  centres.  Although  the  contraction  of  the  pupil  is 
effected  by  the  influence  of  motor  fibres,  which  proceed  to  the  sphincter  of  the 
Iris  from  the  third  pair  of  nerves,  through  the  Ophthalmic  ganglion,  its  dilata- 
tion (as  we  shall  hereafter  see)  depends  upon  the  influence  it  derives  from  the 
Sympathetic  system,  of  which  that  ganglion  forms  part. — Besides  the  contraction 
of  the  pupil,  another  action  of  a  '  reflex '  character  is  produced  through  the  Optic 
nerve  ;  namely,  the  contraction  of  the  Orbicularis  muscle  under  the  influence  of 
strong  light,  or  when  a  foreign  body  is  suddenly  brought  near  the  eye.  But 
this  cannot  be  excited  without  a  consciousness  of  the  visual  impression ;  in  fact, 
it  is  a  movement  of  a  '  consensual '  kind,  produced  by  the  painful  sensation  of 
light,  which  gives  rise  to  the  condition  well  characterized  by  the  term  photo- 
phobia. The  irwoluntary  character  of  it  must  be  evident  to  every  one  who  has 
been  engaged  in  the  treatment  of  diseases  of  the  eyes  ;  and  the  effect  of  it  is 
aided  by  a  similarly-involuntary  movement  of  the  eyeball  itself,  which  is  rotated 
upwards  and  inwards  to  a  greater  extent  than  the  Will  appears  able  to  effect. — 
Another  reflex  movement  excited  through  the  visual  sense,  is  that  of  Sneezing, 


NERVES     OF    SPECIAL     SENSE.  —  OPTIC.  493 

which  is  induced  in  many  individuals  by  the  sudden  exposure  of  the  eyes  to  a 
strong  light :  of  the  purely  automatic  character  of  this  movement  there  can  be  no 
question,  since  it  cannot  be  imitated  voluntarily;  and  that  it  is  not  excito-motor, 
is  proved  by  the  fact  that  it  is  not  excited  unless  the  light  be  seen} 

5'23.  There  is  a  further  peculiarity,  of  a  very  marked  kind,  attending  the 
course  of  the  Optic  nerves ;  this  is  the 

crossing  or  '  decussation  '   which   they  [FIG.  144. 

undergo,  more  or  less  completely,  whilst 
passing  between  their  ganglia  and  the 
eyes  (Fig.  144).  In  some  of  the  lower 
animals,  in  which  the  two  eyes  (from 
their  lateral  position)  have  entirely  dif- 
ferent spheres  of  vision,  the  decussation 
is  complete  ;  the  whole  of  the  fibres 
from  the  right  optic  ganglion  passing 

into  the  left  eye,  and  vice  versd.     This      Course  of  lbr?8  in  tbe  ?b.iaf m.a'  "  exbibited 
~J    >  ,          .,,  „  by  tearing  off  the   superficial  bundles  from  a 

IS   the   case,  for  example,  With  most   of  g^ecimen  hardenedin  spirit.    «.  Anterior  fibres, 
tne  Osseous  Fishes  (as  the  cod,  halibut,  commissural  between  the  two  retinae,    p.  Pos- 
&C.);    and  also,  in    great    part   at   least,  terior  fibres,  commissural  between  the  thalami. 
with  Birds.2      In    the    Human    subject,  a' p'.  Diagram  of  the  preceding.] 
however,  and   in    animals  which,  like 

him,  have  the  axes  of  both  eyes  directed  to  the  same  object,  the  decussation 
seems  less  complete ;  but  there  is  a  very  remarkable  arrangement  of  the  fibres, 
winch  seems  destined  to  bring  the  two  eyes  into  peculiarly  consentaneous  action. 
The  posterior  border  of  the  Optic  Chiasma  is  formed  exclusively  of  commissural 
fibres,  which  pass  from  one  optic  ganglion  to  the  other,  without  entering  the  real 
optic  nerve.  Again,  the  anterior  border  of  the  Chiasma  is  composed  of  fibres, 
which  seem,  in  like  manner,  to  act  as  a  commissure  between  the  two  retinde; 
passing  from  one  to  the  other,  without  any  connection  with  the  optic  ganglia. 
The  tract  which  lies  between  the  two  borders,  and  occupies  the  middle  of  the 
Chiasma,  is  the  true  Optic  Nerve ;  and  in  this  it  would  appear  that  a  portion  of 
the  fibres  decussates,  whilst  another  portion  passes  directly  from  each  Optic  gan- 
glion into  the  corresponding  eye.  The  fibres  which  proceed  from  the  ganglia  to 
the  retinae,  and  constitute  the  proper  Optic  Nerves,  may  be  distinguished  into  an 
internal  and  external  tract.  Of  these,  the  external,  on  each  side,  passes  directly 
onwards  to  the  eye  of  that  side  :  whilst  the  internal  crosses  over  to  the  eye  of 
the  opposite  side.  The  distribution  of  these  two  sets  of  fibres  in  the  retina  of 
each  eye  respectively,  is  such  that,  according  to  Mr.  Mayo,  the  fibres  from  either 
optic  ganglion  will  be  distributed  to  its  own  side  of  loth  eyes,3  the  right  optic 
ganglion  being  thus  exclusively  connected  with  the  outer  part  of  the  retina  of  the 
right  eye,  and  with  the  inner  part  of  the  retina  of  the  left ;  whilst  the  left  optic 
ganglion  is  connected  exclusively  with  the  outer  side  of  the  left  retina,  and  with 
the  inner  side  of  the  right.  Now  as  either  side  of  the  eye  receives  the  images  of 
objects  which  are  on  the  other  side  of  its  axis,  it  follows,  if  this  account  of  the  dis- 
tribution of  the  nerves  be  correct,  that  in  Man,  as  in  the  lower  animals,  each  gan- 

1  A  patient  was  for  some  time  in  the  London  Hospital,  in  whom  there  was  such  an  undue 
impressibility  of  the  retina,  that  she  could  not  remain  in  even  a  moderate  light  without  a 
continual  repetition  of  the  act  of  Sneezing. 

a  See  Solly  on  "  The  Human  Brain,"  Am.  Ed.,  p.  232. 

8  This  arrangement  was  first  hypothetically  suggested  by  Dr.  Wollaston  ("Philos 
Trans,"  1824),  as  facilitating  the  explanation  of  some  of  the  phenomena  of  vision,  and 
more  particularly  single  vision  with  two  eyes.  We  shall  hereafter  see,  however,  that  the 
singleness  of  the  impression  resulting  from  the  formation  of  two  pictures  upon  our  retinae, 
is  not  attributable  to  any  such  anatomical  arrangement,  their  combination  being  a  mental 
process,  and  the  fusion  of  two  dissimilar  pictures  being  requisite  to  enable  us  to  exercise 
one  of  tbe  highest  attributes  of  the  visual  sense,  the  perception  of  projection.  (See  CH\P. 
XV.,  Sect.  5). 


494  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

glion  receives  the  impressions  of  objects  situated  on  the  opposite  side  of  the  body. 
The  purpose  of  this  decussation  may  be,  to  bring  the  visual  impressions,  which 
are  so  important  in  directing  the  movements  of  the  body,  into  proper  harmony 
with  the  motor  apparatus ;  so  that  the  decussation  of  the  motor  fibres  in  the 
pyramids  being  accompanied  by  a  decussation  of  the  optic  nerves,  the  same  effect 
is  produced  as  if  neither  decussated, — which  last  is  the  case  with  Invertebrated 
animals  in  general. 

524.  The  functions  of  the  Auditory  nerve,  or  Portio  Mollis  of  the  7th,  are 
easily  determined,  by  anatomical  examination  of  its  distribution,  and  by  observa- 
tion of  pathological  phenomena,  to  be  analogous  to  those  of  the  two  preceding. 

Atrophy  or  lesion  of  the  trunk  destroys 

[FIG.  145.  the  sense  of  Hearing ;  whilst  irritation 

of  it  produces  auditory  sensations,  but 
does  not  occasion  pain.  From  experi- 
ments made  upon  the  nerve  before  it 
leaves  the  cranial  cavity,  it  appears  satis- 
factorily ascertained,  that  this  nerve  is 
not  endowed  either  with  common  sensi- 
bility, or  with  the  power  of  directly 
stimulating  muscular  movement.  Nor 
can  any  obvious  reflex  actions  be  exe- 
cuted by  irritation  of  this  nerve;  but 
it  seems  nevertheless  by  no  means  im- 
probable, that  the  muscles  which  regu- 
late the  tension  of  the  Tympanum, 
A  view  of  the  origin  and  distribution  of  the  n  j  •  .  .•  i_  • 

Portio  Mollis  of  the  Seventh  pair  or  Auditory  are    Called    !nt°    actl°n     bJ    impressions 

Nerve:  1,  the  medulla  oblongata;  2,  the  pons  made  upon  it  and  reflected  through  the 
Varolii;  3,  4,  the  crnra  cerebelli  of  the  right  auditory  ganglion  in  the  same  manner  as 
side;  5,  the  eighth  pair  of  nerves  ;  6,  the  ninth  the  diameter  of  the  pupil  is  regulated 
pair;  7,  the  auditory  nerve  distributed  to  the  thro  h  the  optic  nerve<  In  the  invo. 
cochlea  and  labyrinth;  8,  the  sixth  pair  of  ,  ,  r  ,  .  ,  .  , 

nerves ;  9,  the  portio  dura  of  the  seventh  pair ;  luntary  start,  however,  which  is  occasioned 
10,  the  fourth  pair;  11,  the  fifth  pair.]  by  a  loud  and  sudden  sound,  we  have  an 

example  of  a  consensual  movement  ex- 
cited through  the  Auditory  nerve,  which  is  evidently  analogous  to  the  closure 
of  the  eyes  to  a  strong  light.  In  certain  morbidly-impressible  states  of  the  ner- 
vous system,  as  will  be  presently  shown  (§  538),  the  effect  of  sounds  on  the  motor 
apparatus  is  far  more  remarkable. — It  has  been  attempted  by  Flourens  to  show, 
that  the  division  of  the  Auditory  nerve,  which  proceeds  to  the  Semicircular 
canals,  has  functions  altogether  different  from  that  portion  which  supplies  the 
Vestibule  and  Cochlea.  This  inference,  however,  is  grounded  only  upon  the 
movements  exhibited  by  animals  in  which  these  nerves  are  irritated;  which 
movements  are  capable  of  a  different  explanation  (§  531). 

525.  The  nerves  which  minister  to  the  sense  of  Taste,  are  destitute  of  the 
peculiarities  which  distinguish  the    preceding;    being    no   other   than    certain 
branches  of  ordinary  afferent   nerves, — the    Fifth  Pair   and   Glosso-pharyngeal 
(§  495) — the  peculiar  endowments  of  which  seem  to  depend  rather  upon  the 
structure  and  actions  of  the  papilla  at  their  peripheral  extremities,  than  upon 
anything  special  in  their  own  character;  for,  as  in   the  case   of  the  ordinary 
nerves  of  '  common '  sensation,  mechanical  irritation  applied  to  them  calls-forth 
indications  of  pain. — From  the  observations  and  experiments  of  M.  01.  Bernard,1 
it  appears  that  the  Facial  nerve  (portio  dura  of  the  7th)  supplies  some  condition 
requisite  for  the  sense  of  Taste,  through  the  branch  known  as  the  Chorda  Tym- 
pani,  which  is  the  motor  nerve  of  the  Lingualis  muscle.     When  paralysis  of  the 
Facial  exists  in  Man,  the  sense  of  taste  is  very  much  impaired  on  the  correspond- 
ing side  of  the  tongue,  provided  that  the  cause  of  the  paralysis  be  seated  above 

1  "Archives  G6n6rales  de  Mddecine,"  1844 


FUNCTIONS    OF    THE    SENSORY    GANGLIA. 

the  origin  of  the  Chorda  Tympani  from  its  trunk.  Similar  results  have  been 
obtained  from  experiments  upon  other  animals.  The  nature  of  the  influence 
afforded  by  this  nerve  is  entirely  unknown ;  and  it  is  the  more  obscure,  as  the 
Chorda  Tympani  contains  no  sensory  filaments. 

526.  Nerves  of  Common  Sensation. — To  the  sense  of  Touch,  all  the  afferent 
nerves  of  the  body  (savt>  *he  nerves  of  special  sense)  appear  to  minister;  in  virtue 
— according  to  the  doctrine  already  propounded  (§  486) — of  the  direct  connec- 
tion of  certain  of  their  fibrils  with  the  Sensorium  commune.     But  the  degree  in 
which  they  are  capable  of  producing  Sensations,  does  not  bear  any  constant  rela- 
tion to  their  power  of  exciting  reflex  actions.     Thus,  the  Glosso-pharyngeal  is 
not  nearly  so  sensitive  as  the  Fifth  pair ;  though  more  powerful  as  an  excitor 
nerve.     The  Par  Vagum  appears  to  have  even  less  power  of  arousing  sensory 
changes,  although  it  is  the  most  important  of  all  the  excitors  to  reflex  action.    So 
again,  the  afferent  nerves  of  the  inferior  extremities,  in  Man,  are  less  concerned 
in  ministering  to  sensations,  than  are  those  of  the  superior;  and  yet  they  appear 
to  be  much  more  efficient  as  excitors  to  muscular  movement. — These  differences 
may  be  accounted-for,  by  supposing  that  the  proportion  which  the  fibres,  having 
their  centre  in  the   gauglionic  matter  of  the  Spinal  Cord,  bears  to  that  of  the 
fibres  which  pass-on  to  the  Sensorium,  is  not  constant,  but  is  liable  to  variation 
in  different  nerves;  the  former  predominating  in  the  Par  Vagum  and  the  Glosso- 
pharyngeal,  whilst  the  latter  are  more  numerous  in  the  Fifth  Pair,  and  in  most 
of  the  Spinal  nerves. 

527.  Motor  Nerves. — No  motor  nerves  issue  from  the  Sensory  Ganglia  with 
the  same  directness  that  afferent  nerves  proceed  towards  them ;  but  the  reflex 
actions  of  these  centres  find  a  ready  channel  in  the  motor  nerves  of  the  Cranio- 
Spinal  axis  generally.     For,  as  we  have  seen  (§  490),  the  motor  tract  of  the  Crura 
Cerebri,  which  is  in  connection  with  the  motor  Encephalic  nerves,  and  also 
(through  the  vesicular  substance  of  the  Spinal  Cord)  with  the  anterior  roots  of 
the  Spinal  nerves,  passes-up  into  the  Corpora  Striata  and  Corpora  Quadrigemina. 
Although  the  direct  connection  of  the  other  ganglia  of  Special  Sense  with  the 
Motor  columns,  is  at  present  a  matter  of  presumption  only,  yet  this  presumption 
is  strongly  supported  by  the  analogy  of  the  Optic  ganglia ;  the  distinctness  of 
this  connection  in  their  case  being  easily  accounted-for,  when  it  is  remembered 
in  how  great  a  degree  the  general  movements  of  the  body  are  guided  by  the 
visual  seuse. 

528.  Functions  of  the  Sensory  Ganglia. — We  have  now  to  consider  what  de- 
ductions may  be  drawn  with  regard  to  the  functions  of  the  Sensory  Ganglia  in 
Man ;  from  the  facts  supplied  by  Comparative  Anatomy,  by  Experimental  in- 
quiry, and  by  Pathological  phenomena.     The  determination  of  these  functions 
may  seem  to  be  the  more  difficult,  as  it  is  impossible  to  make  any  satisfactory 
experiments  upon  the  ganglionic  centres  in  question,  by  isolating  them  com- 
pletely from  the  Cerebral  Hemispheres  above,  and  from  the  Medulla  Oblongata 
and  Spinal  Cord  below.     But  the  evidence  derived  from  Comparative  Anatomy 
appears  to  be  in  this  case  particularly  clear ;  and,  rightly  considered,  affords  us 
nearly  all  the  information  we  require.     In  the  series  of  "  experiments  prepared 
for  us  by  nature,"  which  is  presented  to  us  in  the  descending  scale  of  Animal 
life,  we  witness  the  effects  of  the  gradual  change  in  the  relative  development  of 
the  Sensory  ganglia  and  Cerebral  Hemispheres,  which  are  presented  to  us  in  de- 
scending through  in  the  Vertebrated  scale ;  and  the  results  of  the  entire  with- 
drawal of  the  latter,  and  of  the  sole  operation  of  the  former,  which  are  exhibited 
in  the  higher  Invertebrata  (See  §§  458,  461,  and  PRINC.   or  COMP.  PHYS., 
CHAP,  xiii.,  Am.  Ed.).1 — Thus  we  are  led  by  the  very  cogent  evidence  which 

'  It  is  worthy  of  special  notice,  that  the  development  of  the  Cephalic  ganglia  in  the  In- 
vertebrata always  bears  an  exact  proportion  to  the  development  of  the  eyes ;  the  other 
organs  of  special  sense  being  comparatively  undeveloped ;  whilst  these,  in  all  the  higher 
classes  at  least,  are  instruments  of  great  perfection,  and  are  evidently  connected  most 


496  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

Comparative  Anatomy  supplies,  to  regard  this  series  of  Ganglionic  centres  a?» 
constituting  the  real  Sensorium  ;  each  ganglion  having  the  power  of  rendering 
the  Mind  conscious  of  the  impressions  derived  from  the  organ  with  which  it  is 
connected.  If  this  position  be  denied,  we  must  either  refuse  the  attribute  of 
consciousness  to  such  animals  as  possess  no  other  Encephalic  centres  than  these ; 
or  we  must  believe  that  the  addition  of  the  Cerebral  hemispheres,  in  the  Ver- 
tebrated  series,  alters  the  endowments  of  the  Sensory  ganglia, — an  idea  which  is 
contrary  to  all  analogy. 

529.  So  far  as  the  results  of  Experiments  can  be  relied-on,  they  afford  a  cor- 
roboration  of  this  view.  The  degree  in  which  animals  high  in  the  scale  of 
organization  can  perform  the  functions 'of  life,  without  any  other  centre  of  action 
than  the  Ganglia  of  Special  sense,  the  Medulla  Oblongata,  and  the  Cerebellum, 
appears  extraordinary  to  those  who  are  accustomed  to  regard  the  Cerebral  Hemi- 
spheres as  the  centre  of  all  energy.  From  the  experiments  of  Flourens,1  Hert- 
wig,2  Magendie,3  Longet,4  and  others,  it  appears  that  not  only  Reptiles,  but 
Birds  and  Mammals,  may  survive  for  many  weeks,  or  even  months  (if  their  phy- 
sical wants  be  duly  supplied)  after  the  removal  of  the  entire  Cerebrum.  It  is 
difficult  to  substantiate  the  existence  of  actual  sensation  ;  but  some  of  their  move- 
ments appear  to  be  of  a  higher  kind  than  those  resulting  from  mere  excito-motor 
action.  One  of  the  most  remarkable  phenomena  exhibited  by  such  a  being,  is 
the  power  of  maintaining  its  equilibrium,  which  could  scarcely  exist  without 
consciousness.  If  it  be  laid  upon  the  back,  it  rises  again,  if  pushed,  it  walks. 
If  a  Bird  thus  mutilated  be  thrown  into  the  air,  it  flies ;  if  a  Frog  be  touched,  it 
leaps.  It  swallows  food  and  liquid,  when  they  are  placed  in  its  mouth  ;  and  the 
digestive  operations,  the  acts  of  excretion,  &c.,  take  place  as  usual.  In  the  case 
of  a  Pigeon  experimented-on  by  Malacorps,  which  is  recorded  by  Magendie,  there 
appears  sufficient  proof  of  the  persistence  of  a  certain  amount  of  sensation.  Al- 
though the  animal  was  not  affected  by  a  strong  light  suddenly  made  to  fall  upon 
its  eyes,  it  was  accustomed,  when  confined  in  a  darkened  or  partially  illuminated 
room,  to  seek-out  the  light  parts ;  and  it  avoided  objects  that  lay  in  its  way.  In 
the  same  manner,  it  did  not  seem  to  be  affected  by  sudden  noises ;  but  at  night, 
when  it  slept  with  its  eyes  closed  and  its  head  under  its  wing,  it  would  raise  its 
head  in  a  remarkable  manner,  and  open  its  eyes,  on  the  slightest  noise ;  speedily 
relapsing  into  a  state  of  complete  unconsciousness.  Its  principal  occupation 
was  to  prune  its  feathers  and  scratch  itself.  And  Longet  mentions  that  a  Pigeon 
from  which  he  had  removed  the  entire  Cerebrum,  gave  many  indications  of  con- 
sciousness of  light;  for  not  only  did  the  pupil  contract,  but  the  lids  closed,  when 
a  strong  light  was  suddenly  made  to  fall  upon  the  eye,  the  animal  having  been 
previously  kept  in  darkness }  and  when  a  lighted  candle  was  made  to  move  in  a 
circle  before  it,  the  animal  executed  a  corresponding  movement  with  its  head.5 — 
The  condition  of  such  beings  seems  to  resemble  that  of  a  Man,  who  is  in  a  slum- 
ber sufficiently  deep  to  lose  all  distinct  perception  of  external  objects,  but  who  is 

intimately  with  the  direction  of  the  movements  of  the  animals.  Of  this  fact  we  have  a 
remarkable  illustration  in  the  history  of  the  metamorphosis  of  Insects ;  the  eyes  being 
almost  rudimentary,  and  the  Cephalic  ganglia  comparatively  small,  in  most  Larvae ;  whilst 
both  these  organs  attain  a  high  development  in  the  Imago,  to  whose  actions  the  faculty  of 
sight  is  essential. 

1  "  Recherches  Expe*rimentales  sur  les  proprie'te's  et  lesfonctions  duSysteme  Nerveux," 
lind  edit.,  1845. 

a  "Exper.  de  effect.  Isesion.  in  partibus  Encephali,"  Berol.,  1826. 

8  "  Le5ons  sur  les  Fonctions  du  Systeme  Nerveux,"  Paris,  1839. 

4  "  Traite"  de  Physiologic,"  torn.  ii.  partie  2. 

*  It  must  not  be  forgotten  that,  in  such  experiments,  the  severity  of  the  operation  will 
of  itself  occasion  a  suspension  or  disturbance  of  the  functions  of  parts  that  remain  ;  so  that 
the  loss  of  a  power  must  not  be  at  once  inferred  from  the  absence  of  its  manifestations. 
Hut  the  persistence  of  a  power,  after  the  removal  of  a  particular  organ,  is  a  clear  proof  that 
i<  cannot  be  the  peculiar  attribute  of  that  organ. 


FUNCTIONS    OF    THE    SENSORY    GANGLIA.  497 

yet  conscious  of  sensations,  as  appears  from  the  movements  occasioned  by  light 
or  by  sounds,  or  from  those  which  he  executes  to  withdraw  the  body  from  an 
uneasy  position. 

530  The  results  of  other  experiments  made  upon  the  Sensory  ganglia  them- 
selves, and  upon  the  organs  from  which  they  derive  their  impressions,  confirm 
this  view;  by  showing  that  the  ordinary  movements  are  seriously  perturbed,  and 
that  in  some  instances  a  new  set  of  automatic  movements  is  induced,  when  the 
normal  relations  between  the  sensory  and  motor  apparatus  are  disarranged.  Of 
the  functions  of  the  ganglia  of  special  sense,  those  of  the  Corpora  Quadrige- 
mina  are  the  chief  which  have  been  examined  experimentally.  The  researches 
of  Flourens  and  Hertwig  have  shown,  that  the  connection  of  these  bodies  with 
the  visual  function,  which  might  be  inferred  from  their  anatomical  relations,  is 
thus  substantiated.  The  partial  loss  of  the  ganglion  on  one  side  produces 
partial  loss  of  power  and  temporary  blindness  on  the  opposite  side  of  the  body, 
without  necessarily  destroying  the  mobility  of  the  pupil ;  but  the  removal  of  a 
larger  portion,  or  complete  extirpation  of  it,  occasions  permanent  blindness  and 
immobility  of  the  pupil,  with  temporary  muscular  weakness  on  the  opposite  side. 
This  temporary  disorder  of  the  muscular  system  sometimes  manifests  itself  in  a 
tendency  to  move  on  the  axis,  as  if  the  animal  were  giddy.  No  disturbance  of- 
consciousness  appears  to  be  produced ;  Hertwig  states  that  he  never  witnessed 
the  convulsions,  which  Flourens  mentions  as  a  consequence  of  the  operation,  and 
which  were  probably  occasioned  by  his  incision  having  been  carried  too  deeply. 
As  Longet  has  justly  remarked,  it  is  difficult,  if  not  impossible,  to  remove  one 
or  both  of  these  ganglionic  masses,  without  doing  such  an  injury  to  the  Crura 
Oerebri  on  which  they  repose,  as  shall  in  great  degree  account  for  such  dis- 
turbed movements  (§  534).  Irritation  of  one  of  the  Tubercula  Quadrigemina 
has  been  observed,  both  by  Flourens  and  Longet,  to  produce  contraction  of  the 
pupils  of  loth  eyes. — These  results  of  experiment  are  partly  confirmed  by  Path- 
ological phenomena  in  Man ;  for  there  are  many  instances  on  record,  in  which 
blindness  has  been  one  of  the  consequences  of  diseased  alterations  in  one  or  both 
tubercles;  and  in  some  of  the  cases  in  which  the  lesion  extended  to  parts  seated 
beneath  the  tubercles,  disturbed  movements  were  observed. — The  subservience 
of  these  bodies  to  the  exercise  of  the  visual  sense,  appears,  on  the  whole,  to  be 
the  point  best  established  in  regard  to  their  functions;  and  considering  the 
degree  in  which  this  sense  is  concerned  in  the  regulation  of  the  general  move- 
ments of  the  body,  it  is  not  surprising  that  lesions  of  its  centre  should  occasion 
a  perversion  of  these  movements.  This  appears  the  more  probable  from  the 
fact,  that,  in  animals  whose  Sensory  ganglia  bear  so  large  a  proportion  to  the 
whole  Encephalon,  that  we  must  look  upon  them  as  the  principle  centres  of 
motor  activity,  instead  of  being  chiefly  concerned  (as  in  Man)  in  the  mere 
guidance  of  movements  whose  origin  is  Cerebral,  lesions  of  the  organ  of  sense, 
from  which  the  impressions  that  excite  the  sensori-motor  impulses  are  derived, 
produce  a  corresponding  disturbance.  Thus  Flourens  found  that  a  vertiginous 
movement  may  be  induced  in  Pigeons  by  simply  blinding  one  eye ;  and  Longet 
produced  the  same  effect  by  evacuating  the  humours  of  the  eye. 

531.  It  is  probably  on  the  same  principle,  that  we  are  to  account  for  the 
remarkable  results  obtained  by  Flourens  (Op.  Cit.)  from  section  of  the  portion  of 
the  Auditory  nerve  proceeding  to  the  Semi-circular  canals.  Section  of  the  hori- 
zontal Semi-circular  canal  in  Pigeons,  on  both  sides,  induces  a  rapid  jerking  hori- 
zontal movement  of  the  head,  from  side  to  side  ;  and  a  tendency  to  turn  to  one  side, 
which  manifests  itself  whenever  the  animal  attempts  to  walk  forwards.  Section  of 
a  vertical  canal,  whether  the  superior  or  inferior,  of  both  sides,  is  followed  by  a  vio- 
lent vertical  movement  of  the  head.  And  section  of  the  horizontal  and  vertical 
canals,  at  the  same  time,  causes  horizontal  and  vertical  movements.  Section  of  either 
canal  on  one  side  only,  is  followed  by  the  same  effect  as  when  the  canal  is  divided 
on  both  sides ;  but  this  is  iuferior  in  intensity.  The  movements  continue  to  be 


498  FUNCTIONS   OF   THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

performed  during  several  months.  In  Rabbits,  section  of  the  horizontal  canal  is 
followed  by  the  same  movements  as  are  exhibited  by  Pigeons }  and  they  are  even 
more  constant,  though  less  violent.  Section  of  the  anterior  vertical  canal  causes 
the  animal  to  make  continued  forward  '  somersets  ;'  whilst  section  of  the  posterior 
vertical  canal  occasions  continued  backward  c somersets.'  The  movements  cease 
when  the  animal  is  in  repose ;  and  they  recommence  when  it  begins  to  move, 
increasing  in  violence  as  its  motion  is  more  rapid. — These  curious  results  are 
supposed  by  M.  Flourens  to  indicate,  that  the  nerve  supplying  the  semi-circular 
canals  does  not  minister  to  the  sense  of  hearing,  but  to  the  direction  of  the 
movements  of  the  animal;  but  they  are  fully  explained  upon  the  supposition, 
that  the  normal  function  of  the  semi-circular  canals  is  to  indicate  to  the  animal 
the  direction  of  sounds,  and  that  its  movements  are  partly  determined  by  these ; 
so  that  a  destruction  of  one  or  other  of  them  will  produce  an  irregularity  of 
movement  (resulting  as  it  would  seem,  from  a  sort  of  giddiness  on  the  part  of  the 
animal),  just  as  when  one  of  the  eyes  of  a  bird  is  covered  or  destroyed,  as  in  the 
experiments  previously  cited. 

532.  The  numerous  experiments  which  have  been  made,  for  the  purpose  of 
determining  the  functions  of  the  Thalami  Optici  and  Corpora  Striata,  have  not 
'  yielded  any  very  satisfactory  results  ;  and  this  on  account  of  the  impossibility  of 
completely  isolating  them,  in  such  a  manner  as  to  limit  the  operation  (whether 
this  be  section,  removal,  or  irritation)  to  them  alone.  Thus  it  is  impossible  to 
remove  them,  either  separately  or  conjointly,  without  first  removing  the  Cerebral 
Hemispheres;  and  the  Thalami  cannot  be  entirely  removed,  without  dividing 
the  stratum  of  fibres  which  traverse  their  deeper  portion  in  their  passage  to  the 
Corpora  Striata. — The  Thalami  Optici  have  not  that  relation  to  the  visual  sense 
which  their  designation  would  imply  ;  for  (according  to  the  affirmation  of  Longet) 
they  may  be  completely  destroyed  in  Mammals  and  Birds,  without  destruction  of 
sight  or  loss  of  the  activity  of  the  pupil.  And  irritation  of  one  or  both  of  them 
produces  no  contraction  of  the  pupil.  It  seems  probable,  therefore,  that  the  loss 
of  sight  with  dilatation  and  immobility  of  the  pupil,  which  is  frequently  observed 
in  cases  of  apoplectic  effusion  into  the  substance  of  the  Thalami,  is  really  due  to  the 
compression  of  the  Optic  nerves  which  lie  beneath  them.  These  bodies  appear, 
however,  to  possess  a  very  decided  influence  on  the  power  of  voluntary  move- 
ment; for  although  an  animal  maintains  its  balance,  and  can  be  made  to  move 
onwards,  after  the  removal  of  the  Cerebral  Hemispheres,  and  even  after  the 
removal  of  the  Corpora  Striata,  yet  if  either  of  the  Thalami  Optici  be  removed, 
the  sensibility  and  power  of  voluntary  movement  are  destroyed  on  the  opposite 
side  of  the  body,  and  the  animal  consequently  falls  over  to  that  side  (Longet). 
If,  instead  of  the  entire  removal  of  one  of  the  Thalami,  an  incision  be  made  in 
it  without  the  previous  removal  of  the  Cerebrum,  the  animal  keeps  turning  to 
one  side  in  a  circular  manner  (evolution  du  manege) :  according  to  Longet  and 
Lafargue,  this  movement  is  directed  in  the  rabbit  towards  the  opposite  side ; 
whilst  Flourens  states  that  in  the  frog  its  direction  is  towards  the  injured  side ; 
and  according  to  Schiff !  the  destruction  of  the  three  anterior  fourths  of  this 
organ  in  the  rabbit  determines  this  movement  towards  the  injured  side,  whilst 
that  of  the  posterior  fourth  determines  the  movement  towards  the  opposite  side. 
No  mechanical  irritation  of  the  Thalami  produces  either  signs  of  pain  or  muscu- 
lar movement ;  and  this  fact  might  at  first  appear  to  negative  the  doctrine  that 
these  organs  are  the  ganglia  of  common  sensation.  But  it  must  be  borne  in 
mind  that  the  production  of  pain  by  mechanical  injuries,  is  by  no  means  an 
universal  phenomenon  in  the  case  of  the  neive-trunks  which  minister  to  sensa- 
tion,— the  olfactive,  optic,  and  auditory  nerves  being  exempted;  and  it  need 
occasion  still  less  surprise,  therefore,  that  a  nervous  centre  should  be  destitute  of 
this  kind  of  impressibility. 

553.  The  effects  of  lesions  of  the  Corpora  Striata  are  less  distinctly  marked. 

'  Roser's  und  Wunderlich's  "  Archiv.  fur  Physiol.,  Heilkunde,"  1846,  g  667. 


FUNCTIONS    OF    THE    SENSORY    GANGLIA.  499 

It  was  affirmed  by  Magendie,  that  there  exists  in  them  a  motor  power  which 
excites  backward  movement,  and  that  a  corresponding  power  of  exciting  forward 
movement  exists  in  the  Cerebellum  ;  that  these  two  powers  ordinarily  balance  one 
another;  but  that,  if  either  organ  be  removed,  the  power  of  the  other  will  occa- 
sion a  continual  automatic  movement,  the  removal  of  the  Corpora  Striata  causing 
an  irresistible  tendency  to  forward  progression,  whilst  the  division  of  the  pedun- 
cles of  the  Cerebellum  (according  to  him)  occasions  the  reverse  movement. 
These  assertions,  however,  have  not  been  confirmed  by  other  experimenters.  Ac- 
cording to  Longet  (Op.  cit.),  Schiff,1  and  Lafargue,2  the  results  of  removal  of  the 
Corpora  Striata  with  the  anterior  part  of  the  Cerebral  hemispheres,  are  for  the 
most  part  negative;  for  the  animal  usually  remains  in  a  state  of  profound  stupor, 
although  still  retaining  the  erect  position;  and  it  is  only  when  irritated  by 
pinching  or  pricking,  that  it  will  execute  any  rapid  movements.  No  mechanical 
irritation  of  the  Corpora  Striata  produces  either  signs  of  pain  or  muscular 
movement. 

534.  When  the  fibrous  tracts  which  connect  these  ganglionic  masses  with  the 
Medulla  Oblongata,  and  which  are  commonly  (but  erroneously)  designated  as  the 
Crura  Cerebri,  are  completely  divided,  the  result,  as-  might  be  anticipated,  is  the 
annihilation  of  sensibility  and  of  the  power  of  voluntary  movement  in  the  body 
generally.3  When,  however,  the  Crura  Cerebri  of  a  rabbit  are  not  completely 
divided,  but  one  of  them  is  partially  cut-through,  a  little  in  front  of  the  Pons 
Varolii,  the  animal  is  said  by  Longet  and  Schiff  to  exhibit  a  constant  tendency 
to  turn  towards  the  side  opposite  to  that  of  the  lesion,  so  that  it  performs  the  cir- 
cular evolution  du  mantye  ;  the  diameter  of  its  circle  of  movement  being  smaller, 
in  proportion  as  the  incision  approaches  the  edge  of  the  Pons.  But  if  one  of 
the  Crura  be  completely  divided,  the  animal  then  falls-over  on  the  opposite  side ; 
the  limbs  of  that  side  being  paralysed  to  the  influence  of  the  Encephalic  centres, 
though  they  may  be  still  caused  to  exhibit  reflex  motions.  Hence  it  appears 
that  the  circular  movements  which  are  performed  after  incomplete  lesions  of  the 
Crus  Cerebri  and  Thalamus  Opticus  of  either  side,  are^due  to  the  weakening  of 
the  sensori-motor  apparatus  of  the  opposite  side,  whereby  the  balance  of  the  mus- 
cular actions  of  the  two  sides  is  destroyed.  Nearly  the  same  results  have  been 
obtained  on  this  point  by  Longet,  Lafargue,  and  SchifF.4 

1  "De  vi  motoria  baseos  encephali,"  Bockenhemii,  1845. 

1  "Essai  sur  la  valeur  des  localisations  ence'phaliques,"  &c.,  These  Inaug.,  Paris,  1838. 

•  It  is  considered  by  Longet  that  these  functions  are  not  completely  destroyed,  because 
the  animals  on  which  this  operation  has  been  performed  still  retain  some  power  of  move- 
ment, and  respond  by  cries  to  impressions  that  ordinarily  produce  pain.    There  is  no  proof, 
however,  that  such  actions  are  other  than  'excito-motor;'  they  certainly  cannot  in  them- 
selves be  admitted  as  proving  the  persistence  of  consciousness  in  the  lower  segment  of  the 
Cerebro-Spinal  axis. 

*  [Dr.  Brown-Se"quard,  whose  experimental  researches  have  been  frequently  qioted,  has 
published  the  following  resumi  of  the  phenomena  produced  by  injuries  of  the  nervous 
system.1 

Pourfour  du  Petit  and  Me'he'e  de  la  Touche  were  the  first  experimenters  who  witnessed 
turning  produced  by  an  injury  of  the  nervous  centres.  But  the  first  valuable  researches 
on  this  phenomenon  were  made  by  Magendie  and  Flourens. 

The  parts  of  the  cerebro-spinal  centre  which  may  be  injured  without  producing  turning, 
are:  the  cerebral  hemispheres,  the  cerebellum,  the  corpora  striata,  the  corpus  callosum, 
the  spinal  marrow,  and  the  olfactive  and  optic  nerves."  Injuries  of  all  the  other  parts  of 
the  cerebro-spinal  centres  may  produce  turning  or  rolling. 

These  circulatory  or  rotatory  movements  take  place  sometimes  on  the  same  side  of  the 
body,  and  sometimes  on  the  side  opposite  to  that  portion  of  the  encephalon  which  has  been 
injured. 

1  ["Phil.  Med.  Examiner,"  August,  1852.] 

a  [The  three  nerves  of  the  superior  senses,  the  olfactive,  the  optic,  and  the  auditive,  aro 
considered,  by  the  author  of  the  article  here  quoted,  as  a  part  of  the  nervous  centres. — ED.] 


500  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NEBVOTTS    SYSTEM. 

535.  Considerable  importance  is  attached  by  some  Physiologists  to  the  part  of 
the  Encephalon  known  as  the  Tuber  Annulare,  to  which  the  name  of  Mesoce- 
pliale  has  also  been  given.  This  is  not  altogether  synonymous  with  the  Pons 
Varolii,  as  some  Anatomists  have  represented  it;  for,  while  the  latter  consists  of 
transverse  fibres,  which  form  the  commissure  between  the  hemispheres  of  the 
Cerebellum,  surrounding  and  passing  between  the  longitudinal  fibres  of  the 

A  puncture  of  one  of  the  following  parts  produces  turning  or  rolling  sometimes  on  the 
injured  side,  sometimes  on  the  opposite  : — 

1.  The  anterior  extremity  of  the  thalami  optici,  according  to  Schiff. 

2.  The  crura  cerebri,  according  to  Magendie. 

3.  The  bi-,  or  quadrigeminal  tubercles,  according  to  Flourens. 

4.  The  Pens  Varolii. 

5.  The  posterior  part  of  the  processus  cerebelli  ad  pontem. 

6.  The  auditive  nerve,  according  to  Brown-Se"quard. 

7.  The  medulla  oblongata  at  the  point  of  insertion  of  the  facinl  nerve,  according  to  the 
experiments  of  Brown-Se"qxiard,  in  common  -with  Dr.  Martin-Magron. 

8.  The  medulla  oblongata  outside  of  the  anterior  pyramids,  according  to  Magendie. 

9.  A  great  part  of  the  posterior  face  of  the  medulla  oblongata,  according  to  Brown- 
Se"quard. 

The  parts  of  the  encephalon  which  produce  turning  or  rolling  on  the  opposite  side 
are: — 

1.  The  posterior  extremity  of  the  thalami  optici,  according  to  Schiff. 

2.  The  crura  cerebri,  according  to  Lafargue. 

3.  The  anterior  part  of  the  processus  cerebelli  ad  pontem. 

4.  A  small  part  of  the  medulla  oblongata  before  the  nib  of  the  calamus  scriptorius  and 
behind  the  corpora  olivaria,  according  to  Brown-Se"quard's  experiments  in  common  with 
Dr.  Martin-Magron. 

Some  of  these  two  series  of  parts  ordinarily  produce  turning,  and  others  rolling.  But 
these  two  kinds  of  movements  can  be  produced  by  the  puncture  of  a  single  part  of  the 
encephalon.  Rolling  is  nothing  but  the  exaggeration  of  turning ;  thus,  after  a  puncture 
of  the  medulla  oblongata,  the  animal  at  first  rolls,  and  after  some  instants,  instead  of 
rolling,  it  turns.  If,  when  it  is  turning,  a  slight  puncture  is  made  anew,  close  to  the  first, 
then  the  animal  rolls. 

1.  Turning  and  Rolling  caused  by  tearing  the  Facial  Nerve. — Dr.  Martin-Magron  and  Dr 
Brown-Se"quard  have  discovered  that,  if  the  facial  nerve  of  a  rabbit  or  a  guinea-pig  be 
exposed  at  its  exit  from  the  stylo-mastoid  foramen,  and  then  drawn  away  from  the  cra- 
nium, so  as  to  tear  it  asunder  near  its  origin,  the  animal  begins  in  about  five  minutes  to 
turn  itself  round  and  round,  the  movement  being  from  left  to  right  when  the  nerve  has 
been  thus  torn  on  the  left  side,  and  from  right  to  left  when  it  has  been  torn  on  the  right 
side.     This  rotation  is  generally  preceded  by  convulsive  movements  of  the  eyes,  of  the 
jaws,  and  of  the  head  upon  the  trunk :  and  the  body  is  then  bent  (as  in  pleurosthotonos) 
towards  the  injured  side,  by  the  contraction  of  all  the  longitudinal  muscles  of  that  side, 
the  power  of  which  is  such  as  to  resist  considerable  force  applied  to  extend  them.     The 
movement  at  first  takes  place  in  a  small  circle  ;  but  the  circle  generally  enlarges  more  and 
more,  until  at  last,  after  twenty  or  thirty  minutes,  the  animal  walks  in  a  straight  line. 
There  is  no  paralysis  of  any  muscles,  save  the  facial.     The  effect  is  not  produced,  unless 
the  nerve  be  torn  close  to  its  origin. 

When  the  nerve  on  the  other  side  also  is  torn,  even  after  a  long  interval,  instead  of  the 
tendency  to  turn  to  one  side,  there  is,  at  first,  a  rolling  of  the  body  on  its  longitudinal 
axis,  which  takes  place  towards  the  side  last  operated  on.  After  this  has  continued,  how- 
ever, for  twenty  minutes  or  more,  the  animal  recovers  its  feet,  and  begins  to  turn,  as  after 
the  first  operation,  but  towards  the  other  side.  This  movement  soon  ceases. 

Dr.  Martin-Magron  and  the  author  think  that  the  cause  of  these  phenomena  does  not 
exist  in  the  facial  nerve  itself,  but  in  the  part  of  the  medulla  oblongata  from  which  this 
nerve  originates.1 

2.  Turning  and  Rolling  produced  by  an  Injury  to  the  Medulla  Oblongata. — M.  Magendie a 
says:   "Having  raised  up  the  cerebellum,  I  made  a  section  perpendicularly  to  the  surface 
of  the  fourth  ventricle,  and  at  three  or  four  millimetres  from  the  median  line.     If  I  cut 
on  the  right,  the  animal  will  turn  on  the  right  side ;  if  I  cut  on  the  left,  it  will  turn  on 
the  left  side." 

If  we  suppose  a  plane  cutting  the  medulla  oblongata  transversely  at  the  distance  of 
nearly  two  lines  before  the  nib  of  the  calamus  scriptorius,  the  posterior  face  of  the  medulla 

1  [See  "Gaz.  Me"d.  de  Paris,"  t.  iv.  p.  879.] 

a  ["Precis  Etem.  de  Physiol.,"  Paris,  1836,  t.  i.  p.  414.] 


FUNCTIONS    OF    THE    SENSORY    GANGLIA.  501 

Sensory  and  Motor  tracts  which  constitute  the  Crura  Cerebri,  the  Tuber  Annu- 
lare  (which  exists  in  animals  whose  Cerebellum  has  no  hemispheres)  is  a  projec- 
tion from  the  surface  of  the  proper  Medulla  Oblongata,  containing  a  considerable 
nucleus  of  vesicular  matter.  The  experiments  of  Longet  have  led  him  to  the 
conclusion,  that  this  ganglionic  mass  is  an  independent  centre  of  sensation  and 
of  motor  power;  but  they  do  not  afford  any  clear  information  as  to  its  special 

oblongata  will  be  divided  into  two  parte:  one  before  that  plane  which  the  author  calls 
superior,  and  the  other  behind,  or  inferior. 

Now,  every  puncture  on  that  superior  part  produces  turning  or  rolling  on  the  side  which 
has  been  punctured.  The  slightest  puncture  on  the  processus  cerebelli  ad  medullam  ob- 
longatam  will  produce  a  violent  and  very  rapid  rolling.  As  long  as  the  animal  lives  after 
the  operation,  it  rolls  or  turns  every  time  it  tries  to  walk.  Similar  movements  have  been 
observed  in  men;  as  by  M.  Serres,  in  a  man  in  whom  there  was  an  apoplectic  effusion  in 
the  right  crus  cerebelli,  and  by  M.  Bellehomme,  in  a  woman,  in  whom  an  exostosis  pressed 
on  the  left  crus. 

When  (as  Dr.  Martin-Magron  and  the  author  have  discovered)  a  deep  section  is  made 
on  the  inferior  part  of  the  posterior  face  of  the  medulla  oblongata,  before  the  nib  of  the 
calamus  scriptorius,  turning  is  produced  on  the  side  of  the  body  opposite  to  the  punctured 
side  of  the  medulla.  A  rabbit,  which  lived  thirteen  days  after  the  operation,  had  still  the 
circulatory  movement  a  few  hours  before  dying ;  although  sometimes  the  animal  could 
walk  nearly  straight  for  a  few  seconds. 

3.  Turning  produced  by  a  Puncture  or  a  section  of  the  Acoustic  Nerve.  — Flourens  has  dis- 
covered that  after  the  section  of  the  semicircular  canals,  turning  sometimes  takes  place. 

The  author  has  found  all  the  facts  detailed  in  relation  to  this  subject.  It  was  interesting 
to  know  whether  a  puncture  or  the  section  of  the  auditive  nerve  would  produce  turning. 
As  it  was  impossible  to  operate  on  that  nerve  in  mammals,  he  experimented  on  frogs.  In 
these  amphibia,  it  is  easy  to  find  the  nerve  and  to  act  upon  it.  He  found  that,  after  a 
puncture  or  a  section  on  the  trunk  of  the  nefve,  the  animal  began  instantly  to  turn.  As 
long  as  the  frogs  live,  after  a  puncture  of  the  acoustic  nerve,  they  turn ;  but  the  circle  of 
turning  is  much  smaller  a  short  time  after  the  operation  than  afterwards.  He  has  kept 
such  frogs  alive  for  months. 

4.  On  a  New  Mode  of  Turning. — The  same  experimenter  has  discovered  a  mode  of  turn- 
ing which  has  some  of  the  characters  of  both  turning  and  rolling. 

In  the  circulatory  movement  called  turning  (mouvement  de  manage),  the  body  of  the 
animal  is  bent  on  one  of  the  lateral  sides.  It  has  the  shape  of  an  arch,  and  this  arch  is 
generally  a  part  of  the  circumference  described  by  the  animal  when  turning.  The  smaller 
the  radius  of  that  arch,  the  smaller  is  the  circle  of  turning. 

In  the  new  mode  of  turning,  the  body  of  the  animal  is  not  bent,  and  when  it  walks  it  moves 
laterally,  instead  of  going  forwards.  In  turning,  it  describes  a  circle,  but  the  longitudi- 
nal axis  of  its  body,  instead  of  being  then  a  part  of  the  circumference,  is  a  part  of  a 
radius,  so  that  its  head  is  at  the  circumference,  and  its  tail  towards  the  centre  of  the 
described  circle. 

This  mode  of  turning  has  been  performed  by  animals  on  whom  the  quadrigeminal  tuber- 
cles and  the  pons  Varolii,  on  one  side,  had  been  punctured  by  a  pin.  One  of  the  eyes  was 
convulsed ;  the  other  'was  in  its  normal  condition.  The  convulsed  eye  was  the  right  one, 
and  the  tubercles  punctured  were  those  of  the  left  side. 

5.  On  the  Causes  of  Turning  and  Rolling. — 1.  As  the  slightest  puncture  of  certain  parts 
of  the  encephalon  is  sufficient  to  produce  turning  or  rolling,  it  is  evident  that  those  rota- 
ting movements  do  not  exist  in  consequence  of  an  hemiplegia,  as  Lafargue,  Longet,  and 
Schiff  believe  they  do.     Another  reason  is  that  every  degree  of  hemiplegia  exists  in  man 
without  being  accompanied  by 'turning  or  rolling.     Besides,  these  phenomena  have  been 
observed  in  persons  who  had  no  paralysis  at  all. 

2.  The  theories  of  Magendie  and  Flourens  are  also  opposed  by  the  fact  that  a  slight 
puncture  is  sufficient  to  produce  turning  or  rolling. 

3.  As  to  the  theory  of  Henle",  which  is  based  upon  the  existence  of  convulsions  in  the 
eye,  producing  a  kind  of  vertigo,  it  has  against  it  the  facts  that,  on  one  side,  convulsions 
may  exist  in  the  eyes  without  any  other  disorder  in  the  movements :  and,  on  the  other 
side,  sometimes  turning  or  rolling  exists  without  any  convulsions  in  the  eyes.1 

Nevertheless,  in  many  cases,  the  vertigo  consequent  on  convulsions  of  the  eyes  is  one 
element  of  the  cause  of  turning.  And  in  certain  cases,  paralysis  of  some  parts  of  the 
body  may  facilitate  the  rotatory  movements.  But  their  great  cause  is  the  existence  of  a 
convulsive  contraction  in  some  of  the  muscles,  on  one  side  of  the  body.  These  convulsive 
contractions  are  to  be  found  in  every  case  of  circulatory  or  rotatory  movement.  As  tc 
the  cause  of  these  contractions,  it  exists  in  the  irritation  produced  in  certain  parts  of  the 
encephalon. — ED.] 

1  [See  a  very  remarkable  case  observed  by  Dr.  Lebret,  in  "  Comptes  Rendus  et  Mft'moires 
de  la  Soc.  Biologic,"  annSe  1850,  Paris,  1851,  t.  ii.  p.  7.] 


502  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

attributes.  He  states,  however,  that  convulsive  movements  are  excited  by  irri- 
tating it,  and  especially  by  the  transmission  of  an  electric  current  through  its 
substance.  These  movements,  however,  according;  to  the  testimony  of  Dr.  Todd, 
appear  to  be  of  a  different  character  from  those  which  are  excited  by  the  appli- 
cation of  the  same  stimulus  to  the  Spinal  Cord  and  Medulla  Oblongata;  for  he 
states  that  whilst  the  .convulsions  excited  by  the  transmission  of  the  current  of 
the  magneto-electric  machine  through  the  parts  just  named,  are  tetanic,  the  mus- 
cles being  thrown  into  a  state  of  Jixed  contraction, — those  which  ensue  when  the 
current  is  transmitted  through  the  region  of  the  Mesocephale  and  Corpora  Quad- 
rigemina,  are  epileptic,  being  combined  movements  of  alternate  contraction  and 
relaxation,  flexion  and  extension,  affecting  the  muscles  of  all  the  limbs,  of  the 
trunk,  and  of  the  eyes,  which  roll-about  just  as  in  epilepsy.1 

536.  The  evidence  afforded  by  Pathology,  regarding  the  functions  of  these 
Ganglionic  masses,  is  far  from  being  self-consistent;  and  this  arises,  it  may  be 
surmised,  from  the  circumstance  that  the  effects  of  morbid  changes  (particularly 
of  sanguineous  effusions)  in  any  part  of  the  Encephalon,  extend  themselves  to 
other  parts  than  those  in  which  the  obvious  lesions  are  found ;  as  is  abundantly 
proved  by  the  great  variety  of  phenomena  which   present  themselves  as  the 
results  of  lesions  apparently  similar,  and  by  the  similarity  of  the  phenomena  that 
are  frequently  consequent  upon  lesions  of  very  different  parts.     So  far  as  is  yet 
known,  extensive  disease  of  either  the  Thalamus  Opticus  or  the  Corpus  Striatum 
of  one  side  produces  hemiplegia,  or  paralysis  both  of  sensation  and  motion  on 
the  opposite  side.     The  same  result  very  commonly  follows  an  apoplectic  effusion 
into  the  substance  of  either;  and  although  it  has  been  maintained  that  when  the 
lesion  is  limited  to  the  Corpus  Striatum,  the  posterior  member  is  peculiarly  or 
alone  affected,  and  that  lesion  of  the  Thalamus  Opticus  alone  has  a  special  ten- 
dency to  occasion  paralysis  of  the  anterior  member,  yet  the  careful  analysis  which 
has  been  made  by  Andral2  into  the  pathological  phenomena  afforded  by  seventy- 
five  cases  of  paralysis  in  which  the  apoplectic  effusion  was  limited  to  one  or  other 
of  these  bodies,  does  not  afford  the  least  countenance  to  any  such  doctrine.     And 
it  is  affirmed  by  Longet,  that  injury  or  removal  of  the  Corpus  Striatum  of  one 
side  did  not,  in  his  experiments,  affect  the  posterior  more  than  the  anterior  limb; 
nor  could  he  detect  any  difference  in  the  condition  of  these  limbs  after  the  re- 
moval of  the  Thalamus. 

537.  In  employing  the  information  derived  from  the  foregoing  sources,  as  a 
guide  in  the  enquiry  into  the  part  performed  by  the  Sensory  Ganglia  in  the 
ordinary  operations  of  the  Cerebro-Spinal  system,  we  have  to  distinguish,  as  in 
the  case  of  the  Spinal  Cord,  between  their  operation  as  independent  centres,  and 
their  action  in  subservience  to  the  Cerebrum,  which  is  superposed  upon  them. 
We  have  seen  reason  to  conclude  that,  in  their  former  capacity,  they  are  to  be 
regarded  as  the  true  seat   of  Sensation  (i.  e.  the  material  instruments  through 
which  the  consciousness  becomes  affected  by  external  impressions,)  and  as  the 
instrument,  in  virtue  of  their  own  '  reflex '  power,  of  that  class  of  Instinctive  or 
Automatic  movements,  which  require  to  be  prompted  and  guided  by  sensations, 
and  which  cannot,  therefore,  be  referred  to  the  excito-motor  group.     But  although 
it  is  sufficiently  obvious  that  such  movements  constitute  the  highest  manifesta- 
tions of  Animal  life  in  the  Invertebrata  generally,  and  that  they  are  but  little 
modified  by  any  higher  principle  of  action  even  in  the  lower  Vertebrata,  yet  it  is 
no  less  obvious  that  in  adult  Man,  in  whom  the  Intelligence  and  Will  are  fully 
developed,  we  have  comparatively  little  evidence  of  this  independent  reflex  action 
of  the  Sensory  Ganglia : — all  those  automatic  actions  which    are  immediately 
necessary  for  the  maintenance  of  his  Organic  life,  being  provided-for  by  the 
excito-motor  portion  of  the   apparatus,  so  that   although    sensation   ordinarily 

1  Lumleian  Lectures   '  On  the  Pathology  and   Treatment  of  Convulsive  Diseases,'  in 
"Medical  Gazette,"  May  11,  1849. 

1  "Clinique  Me"dicalo,"  torn.  ii.  p.  664,  et  seq. 


FUNCTIONS  OF  SENSORY  GANGLIA  ; — CONSENSUAL  MOVEMENTS.      503 

accompanies  most  of  them,  it.  is  not  essential  to  them  ;  whilst  those  which  are 
necessary  to  provide  more  remotely  for  its  requirements,  are  for  the  most  part 
committed  to  the  guidance  of  his  Reason.  For  the  impressions  which  have  been 
brought  by  the  afferent  nerves  to  his  Sensorium,  and  which  have  there  produced 
sensations,  do  not  in  general  react  at  once  upon  the  motor  apparatus  (as  they  do 
in  those  animals  in  which  the  Sensory  Ganglia  are  the  highest  of  the  nervous 
centres),  but  usually  transmit  their  influence  upwards  to  the  Cerebrum,  through 
whose  instrumentality  they  give  rise  to  ideas  and  reasoning  processes,  which 
operate  upon  the  motor  apparatus  either  emotionally  or  volitionally.  And  it  is 
for  the  most  part  only  when  this  upward  transmission  is  checked,  either  by  the 
non-development  or  the  functional  inactivity  of  the  Cerebrum,  or  by  its  complete 
occupation  in  some  other  train  of  action, — or,  on  the  other  hand,  when  the  reflex 
action  of  the  Sensory  ganglia  is  called  into  play  with  unusual  potency, — that  we 
have  any  manifestations  of  the  sensori-motor  or  consensual  mode  of  operation 
in  Man,  that  are  at  all  comparable  in  variety  or  importance  to  those  instinctive 
acts  which  are  so  remarkable  in  the  lower  animals  (§  459). 

538.  Still,  sufficient  evidence  of  the  existence  of  this  class  of  reflex  move- 
ments may  be  drawn  from  observation  of  the  actions  of  Man  in  his  ordinary 
condition ;  examples  of  it  being  furnished  (as  we  have  seen)  by  the  closure  of 
the  eyes  to  a  dazzling  light,  the  start  caused  by  a  loud  and  unexpected  sound, 
and  the  sneezing  excited  by  sensory  impressions  on  the  Schneiderian  membrane 
or  on  the  Retina.  To  these  may  be  added  the  vomiting  produced  by  various  sen- 
sory impressions,  as  the  sight  of  a  loathsome  object,  a  disagreeable  smell,  a 
nauseous  taste,  or  that  peculiar  feeling  of  want  of  support  which  gives  rise  to 
*  sea-sickness/  especially  when  combined  with  the  sight  of  continually-shifting 
lines  and  surfaces,  which  itself  in  many  individuals  disposes  to  the  same  state  ; 
the  involuntary  laughter  which  is  excited  by  tickling,  and  also  that  which  some- 
times bursts-forth  at  the  provocation  of  some  sight  or  sound  to  which  no 
ludicrous  idea  or  emotion  can  be  attached;  the  yawning  which  is  excited  by  an 
internal  sensation  of  uneasiness  (usually  arising  from  deficient  respiration),  or  by 
the  sight  or  sound  of  the  act  as  performed  by  another ;  and  those  involuntary 
movements  of  the  body  and  limbs,  excited  by  uneasy  sensations,  (probably  mus- 
cular) which  are  commonly  designed  as  'the  fidgets.'  When  the  reflex  activity 
of  the  Sensory  ganglia  is  more  strongly  excited,  in  consequence  either  of  an 
unusual  potency  of  the  sensory  impressions,  or  of  an  unusual  excitability  of  this 
part  of  the  nervous  centres,  a  much  greater  variety  of  sensori-motor  actions  is  wit- 
nessed. The  powerful  involuntary  contraction  of  the  orbicularis  and  of  the  muscles 
which  roll  the  eyeball  upwards  and  inwards,  in  cases  of  excessive  irritability  of  the 
retina  (§  522),  is  one  of  the  best  examples  of  this  kind;  but  another  very  curious 
illustration  is  afforded  by  the  involuntary  abridgement  of  the  excito-motor  actions 
of  respiration,  when  the  performance  of  these  is  attended  with  pain, — the 
dependence  of  this  abridgement  upon  the  direct  stimulus  of  sensation,  rather 
than  upon  voluntary  restraint,  being  obvious  from  the  fact  that  it  often  presents 
itself  on  one  side  only,  a  limitation  which  the  Will  cannot  imitate.  Again,  there 
are  certain  Convulsive  disorders  (Sect.  8)  which  appear  to  depend  upon  an  undue 
excitability  of  these  centres,  the  paroxysms  being  excited  by  impressions  which 
act  through  the  organs  of  sense,  and  are  not  thus  operative  unless  the  patient  be 
conscious  of  them;  thus  in  Hydrophobia,  we  observe  the  immediate  influence 
of  the  sight,  sound  or  contact,  of  liquids,  or  of  the  slightest  currents  of  air,  in 
exciting  muscular  contractions;  and  in  many  Hysteric  subjects,  the  sight  of  a 
paroxysm  in  another  individual  is  the  most  certain  means  of  its  induction  in 
themselves.  A  remarkable  case  of  this  general  exaltation  of  purely  sensorial 
excitability  has  been  recorded  by  Dr.  Cowan ;  who  gives  the  following  account  of 
its  phenomena,  which  can  scarcely  be  referred  to  any  other  than  this  category 
"  The  shadow  of  a  bird  crossing  the  window,  though  blind  and  bed-curtains  are 
closed,  the  displacement  of  the  smallest  portion  of  the  wick  of  a  candle,  the 


504  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

slightest  changes  in  the  firelight,  induced  a  sudden  jerking  of  the  spinal  muscles, 
extending  to  the  arms  and  legs  when  violent,  and  this  without  the  slightest  men- 
tal emotion  of  any  kind  beyond  a  consciousness  of  the  movement.  At  times  the 
vocal  organs  are  implicated,  and  a  slight  cry,  quite  involuntary,  takes  place.  At 
these  periods  she  is  unusually  susceptible  of  all  noises,  especially  the  least  expected 
and  least  familiar.  Movements  in  the  next  house  inaudible  to  others,  the  slightest 
rattle  in  the  lock  of  a  door,  tearing  a  morsel  of  paper,  and  a  thousand  little 
sources  of  sound  not  to  be  catalogued,  induce  results  similar  to  those  of  visual 
impressions."1 

539.  It  is,  however,  when  the  Cerebrum  is  not  in  a  state  which  renders  it 
capable  of  receiving  and  acting-upon  Sensorial  impressions,  that  we  find  the  in- 
dependent  reflex    activity  of  the    Sensory  ganglia    most    strikingly  displayed. 
Thus  in  the  Infant,  for  some  time  after  its  birth,  it  is  obvious  to  an  attentive 
observer,  that  a  large  part  of  its  movements  are  directly  prompted  by  sensations 
to  which  it  can  as  yet  attach  no  distinct  ideas,  and  that  they  do  not  proceed  from 
that  purposive  impulse  which   is  essential  to  render  them  voluntary.     This  is 
well  seen  in  the  efforts  which  it  makes  to  find  the  nipple  with  its  lips ;  being 
probably  guided  thereto  at  first  by  the  smell,  but  afterwards  by  the  sight  also; 
when  the  nipple  has  been  found,  the  act  of  suction  is  purely  excito-motor,  as 
already  explained.     So  in  the  Idiot,  whose  brain  has  never  attained  its  normal 
development,  the  influence  of  sensations  in  directly  producing  respondent  move- 
ments is  obvious  to  all  who  examine  his  actions  with  discrimination ;  and  a  re- 
markable case  will  be  cited  hereafter  (Sect.  8),  in  which  an  entire,  though  tem- 
porary suspension  of  Cerebral  power,  reducing  the  subject  of  it  to  the  condition 
of  one  of  the  lowest  Vertebrata,  gave  a  very  satisfactory  proof  of  the  independ- 
ent activity  of  this  division  of  the  Encephalic  centres. 

540.  But  we  do  not  require  to  go  so  far  in  search  of  characteristic  examples 
of  this  kind  of  reflex  action ;  since   they  are  afforded  by  the  performance   of 
habitual  movements,  which  are  clearly  under  Sensorial  guidance,  when  the  Cere- 
brum is  occupied  in  some  train  of  action  altogether  disconnected  with   them. 
An  individual  who  is  subject  to  'absence  of  mind/  may  fall  into  a  reverie  whilst 
walking   the  streets;  his  attention  may  be  entirely  absorbed  in   his  train  of 
thought,  and  he  maybe  utterly  unconscious  of  any  interruption  in  its  continuity; 
and  yet,  during  the  whole  of  that  time,  his  limbs  shall  have  been  in  motion, 
carrying  him  along  the  accustomed  path,  whilst  his  vision  shall  have  given  the 
direction  to  these  movements,  which  is  requisite  to  guide  him  along  a  particular 
line,  or  to  move  him  out  of  it  for  the  avoidance  of  obstacles.     As  already  pointed- 
out  (§  514),  there  seems  strong  reason  for  regarding  the  ambulatory  movements 
of  the  limbs  as  in  themselves  excito-motor;  but  the  guidance  of  these  move- 
ments by  the  visual  sense,  indicates  the  participation  of  the  Sensoriurn  in  this 
remarkable  performance.  —  It  has  been  maintained  by  some  Metaphysicians  and 
Physiologists,  that  these  'secondarily  automatic'  actions  always  continue  to  be 
voluntary,  because  their  performance  is  originally  due  to  a  succession  of  volitional 
acts,  and  because,  in  any  particular  case,  it  is  the  Will  which  first  excites  them, 
whilst  an  exertion  of  the  Will  serves  to  check  them  at  any  time.     But  this  doc- 
trine involves  the  notion,  that  the  Will  is  in  a  state  of  pendulum-like  oscillation 
between  the  train  of  thought  and  the  train  of  movement;  whereas  nothing  is 
more  certain  to  the  individual  who  is  the  subject  of  both,  than  that  the  former 
may  be  as  uninterrupted  as  if  his  body  were  perfectly  at  rest,  and  his  reverie 
were  taking  place  in  the  quietude  of  his  own  study.     And  as  it  commonly  hap- 
pens, that  the  direction  taken  is  that  in  which  the  individual  is  most  in  the  habit 
of  walking,  it  will  not  unfrequently  occur  that  if  he  had  previously  intended  to 
pursue  some  other,  he  finds  himself,  when  his  reverie  is  at  an  end,  in  a  locality 
which  may  be  very  remote  from  that  towards  which  his  walk  was  originally  des* 

1  »  Lancet,"  Oct.  4,  1845. 


FUNCTIONS    OF    THE    SENSORY    GANGLIA.  505 

lined;  which  would  not  be  the  case,  if  his  movements  had  been  still  und3r  the 
purposive  direction  of  the  will.  And  although  it  is  perfectly  true  that  these 
movements  can  be  at  any  time  checked  by  an  effort  of  the  will,  yet  this  does  not 
really  indicate  that  the  will  has  been  previously  engaged  in  sustaining  them ; 
since,  for  the  will  to  act  upon  them  at  all,  the  attention  must  be  recalled  to  them, 
and  the  Cerebrum  must  be  liberated  from  its  previous  self-occupation.  And  the 
gradual  conversion  of  a  volitional  into  an  automatic  train  of  movements,  so  that 
at  last  this  train,  once  started,  shall  continue  to  run-down  of  itself,  will  be  found 
to  be  less  improbable  than  it  would  at  first  appear,  when  it  comes  to  be  under- 
stood that  the  mechanism  of  both  sets  of  actions  is  essentially  the  same,  and  that 
they  merely  differ  as  regards  the  nature  of  the  stimulus  which  originally  excites 
them  (§  549 ).  That  the  same  automatic  movements  are  not  excited  by  the  same 
sensations,  when  the  Cerebrum  is  in  its  ordinary  state  of  functional  connection 
with  the  Sensorium,  is  a  fact  entirely  in  harmony  with  the  principle  already  laid- 
down  (§§  468 — 470).  The  complete  occupation  of  the  mind  in  other  ways,  as 
in  close  conversation  or  argument,  or  even  (it  may  be)  in  the  voluntary  direction 
of  some  other  train  of  muscular  movements,  is  no  less  favourable  than  the  state 
of  reverie,  to  that  independent  action  of  the  Automatic  centres  which  has  been 
now  described. 

541.  In  the  state  of  entire  functional  activity  of  the  nervous  centres  of  Man, 
however,  there  can  be  no  doubt  that  the  operation  of  the  Sensory  Ganglia  is 
entirely  subordinated  to  that  of  the  Cerebrum ;  and  that  it  furnishes  an  essential 
means  of  connection  between  the  actions  of  the  Cerebrum  on  the  one  hand,  and 
those  of  the  organs  of  Sense  and  Motion  on  the  other,  by  the  combination  of 
which  the  Mind  is  brought  into  relation  with  the  external  world.  For,  in  the 
first  place,  it  may  be  affirmed  with  certainty,  that  no  mental  action  can  be  origin- 
ally excited,  save  by  the  stimulus  of  Sensations  ;  and  it  is  the  office  of  the  Sensory 
ganglia  to  form  these  out  of  the  impressions  brought  to  them  from  the  organs  of 
sense,  and  to  transmit  such  sensorial  changes  to  the  Cerebrum.  But  they  have 
a  no  less  important  participation  in  the  downward  action  of  the  Cerebrum  upon 
the  motor  apparatus;  for  no  voluntary  action  can  be  performed  without  the  assist- 
ance of  a  (jiiiding  sensation  as  was  first  prominently  stated  by  Sir  C.  Bell.1  —  In 
the  majority  of  cases,  the  guiding  or  controlling  sensation  is  derived  from  the 
muscles  themselves,  of  whose  condition  we  are  rendered  cognizant  by  the  sen- 
sory nerves  with  which  they  are  furnished ;  but  there  are  certain  cases  in  which 
it  is  ordinarily  derived  from  one  of  the  special  senses,  and  in  which  the  *  muscu- 
lar sense '  (§  556)  can  only  imperfectly  supply  the  deficiency  of  such  guidance  j 
whilst,  again,  if  the  '  muscular  sense '  be  deficient,  one  of  the  special  senses  may 
supply  the  requisite  information.  The  proof  of  this  necessity  is  furnished  by 
the  entire  impossibility  of  making  or  sustaining  voluntary  efforts,  without  a 
guiding  sensation  of  some  kind.  Thus,  in  complete  anaesthesia  of  the  lower  ex- 
tremities, without  loss  of  muscular  power,  the  patient  is  as  completely  unable  to 
walk,  as  if  the  motor  nerves  had  also  been  paralyzed,  unless  the  deficient  senso- 
rial guidance  be  replaced  by  some  other;  and  in  similar  affections  of  the  upper 
extremities,  there  is  a  like  inability  to  raise  the  limb  or  to  sustain  a  weight. 
But  in  such  cases,  the  deficiency  of  the  ' muscular  sense'  may  be  made  good  by 
the  visual ;  thus,  the  patient  who  cannot  feel  either  the  contact  of  his  foot  with 
the  ground,  or  the  muscular  effort  he  is  making,  can  manage  to  stand  and  walk 
by  looking  at  his  limbs;  and  the  woman  who  cannot  feel  the  pressure  of  her 
child  upon  her  arms,  can  yet  sustain  it  so  long  as  she  keeps  her  eyes  fixed  upon 
it,  but  no  longer, — the  muscles  ceasing  to  contract,  and  the  limb  dropping  power- 
less, the  moment  that  the  eyes  are  withdrawn  from  it.  Thus  it  is,  too,  that 
when  we  are  about  to  make  a  muscular  effort,  the  amount  of  force  which  we  put- 
forth  is  governed  by  the  mental  conception  of  that  which  will  be  required,  as 

1  See  his  chapter  '  On  the  Nervous  Circle  which  connects  the  voluntary  muscles  with  the 
Brain,'  in  his  work  '•  On  the  Nervous  System  of  the  Human  Body." 


506  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

indicated  by  the  experience  of  former  sensations;  just  as  the  contractions  of  the 
muscles  of  vocalization  are  regulated  by  the  conception  of  the  sound  to  be  pro- 
duced. Hence  if  the  weight  be  unknown  to  us,  and  it  prove  either  much 
heavier  or  much  lighter  than  was  expected,  we  find  that  we  have  put-forth  too 
little  or  too  great  a  muscular  effort. 

542.  There  are  two  groups  of  muscular  actions,  however,  which,  although  no 
less  voluntary  in  their  character  than  the  foregoing,  are  yet  habitually  guided  by 
other  sensations  than  those  derived  from  the  muscles  themselves.  These  are,  the 
movements  of  the  Eyeball,  and  those  of  the  Vocal  apparatus. — The  former  are 
directed  by  the  visual  sense,1  by  which  the  action  of  the  muscles  is  guided  and 
controlled,  in  the  same  manner  as  that  of  other  muscles  is  directed  by  their  own 
'  muscular  sense';  and  hence  it  happens  that,  when  we  close  our  eyes,  we  cannot 
move  them  in  any  required  direction,  without  an  effort  that  strongly  calls-forth 
the  muscular  sense,  by  which  the  action  is  then  guided.  In  persons  who  have 
become  blind  after  having  once  enjoyed  sight,  an  association  is  formed  by  habit 
between  the  muscular  sense  and  the  contractile  action,  that  enables  the  former 
to  serve  as  the  guide  after  the  loss  of  the  visual  sense ;  but  in  those  who  are 
born  perfectly  blind,  or  who  have  become  so  in  early  infancy,  this  association  is 
never  formed,  and  the  eyes  of  such  persons  exhibit  a  continual  indeterminate 
movement,  and  cannot  by  any  amount  of  effort  be  steadily  fixed  in  one  spot,  or 
be  turned  in  any  definite  direction.  A  very  small  amount  of  the  visual  sense, 
however,  such  as  serves  merely  to  indicate  the  direction  of  light,  is  sufficient  for 
the  government  of  the  movements  of  the  eyeball. — In  the  production  of  vocal 
sounds,  again,  that  nice  adjustment  of  the  muscles  of  the  Larynx,  which  is 
requisite  to  the  giving-forth  of  determinate  tones,  is  ordinarily  directed  by  the 
auditory  sense  :  being  learned  in  the  first  instance  under  the  guidance  of  the 
sounds  actually  produced  ;  but  being  subsequently  effected  voluntarily,  in  accord- 
ance with  the  mental  conception  (a  sort  of  inward  sensation)  of  the  tone  to  be 
uttered,  which  conception  cannot  be  formed,  unless  the  sense  of  hearing  has 
previously  brought  similar  tones  to  the  mind.  Hence  it  is  that  persons  who  are 
born  deaf,  are  also  dumb.  They  may  have  no  malformation  of  the  organs  of 
speech  ;  but  they  are  incapable  of  uttering  distinct  vocal  sounds  or  musical 
tones,  because  they  have  not  the  guiding  conception,  or  recalled  sensation,  of 
the  nature  of  these.  By  long  training,  however,  and  by  imitative  efforts,  directed 
by  muscular  sensations  in  the  larynx  itself,  some  persons  thus  circumstanced  have 
acquired  the  power  of  speech ;  but  the  want  of  a  sufficiently  definite  control  over 
Ihe  vocal  muscles  is  always  very  evident  in  their  use  of  the  organ. — It  is  very 
rarely  that  a  person  who  has  once  enjoyed  the  sense  of  hearing,  afterwards 
becomes  so  completely  deaf,  as  to  lose  all  auditory  control  over  his  vocal  organs. 
An  example  of  this  kind,  however,  has  been  communicated  to  the  public  by  a 
^ell-known  author,  as  having  occurred  in  himself;  and  the  record  of  his  expe- 
riences2 contains  many  points  of  much  interest.  The  deafness  was  the  result  of 
an  accident  occurring  in  childhood,  which  left  him  for  some  time  in  a  state 
of  extreme  debility;  and  when  he  made  the  attempt  to  speak,  it  was  with  con- 
siderable pain  in  the  vocal  organs.  This  pain  probably  resulted  from  the  unac- 
iustomed  effort  which  it  was  necessary  to  make,  when  the  usual  guidance  was 
wanting;  being  analogous  to  the  uneasiness  which  we  experience,  when  we 
attempt  to  move  our  eyes  with  the  lids  closed.  His  voice  at  that  time  is 
described  as  being  very  similar  to  that  of  a  person  born  deaf-and-dumb,  but  who 
has  been  taught  to  speak.  With  the  uneasiness  in  the  use  of  the  vocal  organs, 
was  associated  an  extreme  mental  indisposition  to  their  employment;  and  thus, 
for  some  years,  the  voice  was  very  little  exercised.  Circumstances  afterwards 
forced  it,  however,  into  constant  employment;  and  great  improvement  suhse- 

1  See  Dr.  Alison's  Memoir  on  the  « Anatomical  and  Physiological  Inferences  from  the 
Study  of  the  Nerves  of  the  Orbit,'  in  "  Trans,  of  Roy.  Soc.  of  Edinb.,"  vol.  xv. 
J  See  the  "  Lost  Senses,"  by  Dr.  Kitto ;  vol.  i.,  chapters  2  and  2 


FUNCTIONS   OF   THE    SENSORY   GANGLIA: — MUSCULAR    SENSE.       507 

quently  took  place  in  the  power  of  vocalization,  evidently  by  attention  to  the 
indications  of  the  muscular  sense.  It  is  a  curious  circumstance,  fully  confirming 
this  view,  that  the  words  which  had  been  in  use  previously  to  the  supervention 
of  the  deafness,  were  still  pronounced  (such  of  them,  at  least,  as  were  kept  in 
employment)  as  they  had  been  in  childhood;  the  muscular  movements  concerned 
in  their  articulation  having  still  been  guided  by  the  original  auditory  conception, 
in  spite  of  the  knowledge  derived  from  the  information  of  others,  that  such  pro- 
nunciation was  erroneous.  On  the  other  hand,  all  the  words  subsequently 
learned  were  pronounced  according  to  their  spelling ;  the  acquired  associations 
between  the  muscular  sensations  and  the  written  signs  being  in  this  case  the 
obvious  guide. 

543.  It  is  through  the  '  muscular  sense',  in  combination  with  the  visual  and 
tactile,  that  those  movements  are  regulated,  which  are  concerned  alike  in  ordi- 
nary progression,  and  in  the  maintenance  of  the  equilibrium  of  the  body.  That 
the  visual  sense  has,  in  most  persons,  a  large  share  in  this  regulation,  is  evident 
from  the  simple  fact,  that  no  one  who  has  not  been  accustomed  to  the  deprivation 
of  it,  can  continue  to  walk  straight-forwards,  when  blind-folded,  or  in  absolute 
darkness,  towards  any  point  in  the  direction  of  which  he  may  have  been  at  first 
guided.  But  the  blind  man,  who  has  been  accustomed  to  rely  exclusively  upon 
his  muscular  sense,  has  BO  difficulty  in  keeping  to  a  straight  path;  and  moves 
onwards  with  a  confidence  which  is  in  remarkable  contrast  with  the  gait  of  a  man 
who  has  been  deprived  of  sight  for  the  occasion  only.  In  fact,  as  Mr.  Mayo  has 
well  remarked,1  in  our  ordinary  movements,  "  we  lean  upon  our  eyesight  as  upon 
crutches." — When  our  vision,  however,  instead  of  aiding  and  guiding  us,  brings 
to  the  mind  sensations  of  an  antagonistic  character,  our  movements  become  uncer- 
tain, from  the  loss  of  that  power  of  guidance  and  control  over  them,  which  the 
harmony  of  the  two  sensations  usually  gives.  Thus  a  person  unaccustomed  to 
look  down  heights,  feels  insecure  at  the  top  of  a  tower  or  precipice,  although  he 
knows  that  his  body  is  properly  supported ;  for  the  void  which  he  sees  below  him 
contradicts  (so  to  speak)  the  tactile  sensations  by  which  he  is  made  conscious  of 
the  due  equilibrium  of  his  body.  So,  again,  although  any  one  can  walk  along  a 
narrow  plank,  which  forms  part  of  the  floor  of  a  room,  or  which  is  elevated  but 
a  little  above  it,  without  the  least  difficulty,  and  even  without  any  consciousness 
of  effort,  if  that  plank  be  laid  across  a  chasm,  the  bottom  of  which  is  so  far 
removed  from  the  eye  that  the  visual  sense  gives  no  assistance,  even  those  who 
have  braced  their  nerves  against  all  emotional  distraction,  feel  that  an  effort  is 
requisite  to  maintain  the  equilibrium  during  their  passage  over  it ;  that  effort 
being  aided  by  the  withdrawal  of  the  eyes  from  the  abyss  below,  and  the  fixation 
of  them  on  a  point  beyond,  which  at  the  same  time  helps  to  give  steadiness  to 
the  movements,  and  distracts  the  mind  from  the  sense  of  its  danger.  The  degree 
in  which  the  *  muscular  sense'  is  alone  sufficient  for  the  guidance  of  such  move- 
ments, when  the  mind  has  no  consciousness  of  the  danger,  and  when  the  visual 
sense  neither  affords  aid  nor  contributes  to  distract  the  attention,  is  remarkably 
illustrated  by  the  phenomena  of  Somnambulism ;  for  the  sleep-walker  traverses, 
without  the  least  hesitation,  the  narrow  parapet  of  a  house,  and  crosses  narrow 
and  insecure  planks,  clambers  roofs,  &c.,  under  circumstances  that  clearly  indi- 
cate the  nature  of  the  guidance  by  which  he  is  directed  (§  693). — The  depend- 
ence of  our  ordinary  power  of  maintaining  our  equilibrium,  upon  the  combination 
of  the  guiding  sensations  derived  through  the  sight  and  the  touch,  is  further  well 
illustrated,  as  Mr.  Mayo  has  pointed-out  (loc.  cit.),  by  what  happens  to  a  lands- 
man on  first  going  to  sea.  "  It  is  long  before  the  passenger  acquires  his  '  sea 
iegs/  At  first,  as  the  ship  moves,  he  can  hardly  keep  his  feet;  the  shifting 
lines  of  the  vessel  and  surface  of  the  water  unsettle  his  visual  stability ;  the 
different  inclinations  of  the  planks  he  stands-on,  his  muscular  sense.  la  a  short 
time,  he  learns  to  disregard  the  shifting  images  and  changing  motions,  or  acquires 

*  "Outlines  of  Physiology,"  3rd  Edit.,  p.  355. 


508  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS    SYSTEM, 

facility  in  adapting  himself  (like  one  on  horseback)  to  the  different  alterations  in 
the  line  of  direction  in  his  frame/'  And  when  a  person  who  has  thus  learned 
by  habit  to  maintain  his  equilibrium  on  a  shifting  surface,  first  treads  upon  firm 
ground,  he  feels  himself  almost  as  much  at  fault  as  he  did  when  he  first  went  to 
sea :  and  it  is  only  after  being  some  time  on  shore,  that  he  is  able  to  resume  his 
original  manner  of  walking.  Indeed,  most  of  those  who  spend  the  greater  pan 
of  their  time  at  sea,  acquire  a  peculiar  gait,  which  becomes  so  habitual  to  them, 
that  they  are  never  able  to  throw  it  off: 

544.  But  further,  there  is  very  strong  physiological  evidence,  that  the  Sensory 
Ganglia  are  not  merely  the  instruments  whereby  our  voluntary  movements  are 
directed  and  controlled,  in  virtue  of  the  guiding  sensations  which  they  furnish, 
but  that  they  are  actually  the  immediate  centres  of  the  motor  influence  which 
excites  muscular  contractions,  in  obedience  to  impulses  transmitted  downwards 
from  the   Cerebrum.     It  has  usually  been  considered  that  the  Cerebrum  acts 
directly  upon  the  muscles,  in  virtue  of  a  direct  continuity  of  nerve-fibres  from 
the  grey  matter  of  its  convolutions,  through  the  Corpora  Striata,  the  motor  tract 
of  the  Medulla  Oblongata,  the  anterior  portion  of  the  Spinal  Cord,  and  the  an- 
terior roots  of  the  nerves ;  and  that  in  the  performance  of  any  voluntary  move- 
ment, the  Will  determines  the  motor  force  to  the  muscle  or  set  of  muscles,  by 
whose  instrumentality  it  may  be   produced.      To  this   doctrine,  however,  the 
anatomical  facts  already  stated  (§  519)  constitute  a  very  serious  objection;  for 
the  motor  tract  cannot  be  stated  with  certainty  to  have  any  higher  origin  than 
the  Corpora  Striata ;  and  it  is  impossible  to  imagine  that  the  fibres  which  con- 
verge towards  the  surface  of  these  bodies  from  all  parts  of  the  Cerebrum,  can  be 
so  closely  compacted-together,  as  to  be  included  in  the  motor  columns  of  the 
Spinal  Axis.     The  fact  would  rather  seem  to  be,  that  these  converging  fibres 
bear  the  same  kind  of  anatomical  relation  to  the  Corpora  Striata  and  the  other 
Sensorial  centres  of  motor  power,  as  do  the  fibres  of  the  afferent  nerves  which 
proceed  to  them  from  the  Retina,  the  Schneiderian  membrane,  and  other  peri- 
pheral expansions  of  nervous  matter;  and  hence  we  might  infer  that  the  nerve- 
force  generated  in  the  convolutions,  instead  of  acting  immediately  on  the  motor 
nerves,  is  first  directed  towards  the  Automatic  centres,  and  excites  the  same  kind 
of  motor  response  in  them,  as  would  be  given  to  an  impression  transmitted  to 
them  through  a  sensory  nerve.     We  shall  find  that  such  a  view  of  the  structural 
arrangements  of  these  parts  is  in  remarkable  accordance  with  their  functional 
relations,  as  indicated  by  a  careful  analysis  of  the  mechanism  of  what  is  com- 
monly regarded  as  'voluntary'  movement.     The   Cerebrum,  as  will  be  shown 
hereafter  (Sects.  5,  6),  may  thus  call  the  motor  apparatus  into  action,  as  the  in- 
strument either  of  ideas,  of  emotions,  or  of  volitional  determinations;  but  we 
may  limit  our  present  examination  to  voluntary  movements  alone,  these  having 
been  usually  regarded  as  in  such  complete  antagonism  to  those  of  the  automatic 
group,  that  even   separate  sets  of  nerve-fibres   have  been  thought  requisite,  to 
account  for  the  transmission  of  these  two  distinct  orders  of  motor  impulses  to 
the  muscles. 

545.  Now  in  the  first  place,  it  may  b^  asserted  with  some  confidence,  that  no 
effort  of  the  Will  can  exert  that  direct  influence  on  the  muscles,  which  our  ordi- 
nary phraseology,  and  even  the  language  of  scientific  reasoners,  would  seem  to 
imply;  but  on  the  other  hand,  that  the  Will  is  solely  concerned  in  determining 
the  result;  the  selection  and  combination  of  muscular  movements  required  tc 
bring  about  this  result,  not  being  effected  by  the  Will,  but  by  some  intermediate 
agency.     If  it  were  otherwise,  we  should  be  dependent  upon  anatomical  know- 
ledge for  our  power  of  performing  the  simplest  movement  of  the  body;  whereas 
we  find  the  fact  to  be,  that  the  man  who  has  not  the  least  idea  of  the  mechanism 
of  muscular  action,  can  acquire  as  complete  a  command  over  his  movements,  and 
fan  adapt  them  as  perfectly  to  the  desired  end,  as  the  most  accomplished  anato- 
mist could  do.     Further,  we  cannot,  by  any  exertion  of  the  will,  single-out  a 


INSTRUMENTALITY  OF  SENSORY  GANGLIA  IN  VOLUNTARY  MOVEMENT.      509 

particular  muscle,  and  throw  it  into  contraction  by  itself,  unless  that  muscle  be 
one  which  is  alone  concerned  in  the  action  that  we  can  voluntarily  perform ;  and 
even  then  we  single  it  out  by  willing  the  action.  Thus  we  can  put  the  levator 
palpebrse  in  action  by  itself;  but  this  we  do,  not  by  any  conscious  determination 
of  power  to  the  muscle  itself,  but  by  willing  to  raise  the  eyelids;  and  it  is  only 
by  our  anatomical  knowledge,  that  we  know  that  but  a  single  muscle  is  concerned 
in  this  morement.  So  far  as  our  own  consciousness  can  inform  us,  there  is  no 
difference  between  the  mechanism  of  this  action  and  that  of  the  flexion  of  the 
knee  or  elbow-joint;  and  yet  in  these  latter  movements,  several  muscles  are  con- 
cerned, not  one  of  which  can  be  singled-out  by  an  effort  of  the  will,  and  thrown 
into  action  separately  from  the  rest. — The  idea  that  the  will  is  directly  exerted 
upon  the  muscles  called  into  action  to  produce  a  particular  movement,  may  seem 
to  derive  some  support  from  the  sense  of  muscular  effort  of  which  we  are  con- 
scious in  making  the  exertion,  and  which  we  refer  to  the  muscles  which  are  con- 
cerned in  it;  but  this  sense  of  effort  is  nothing  else  than  the  'muscular  sense ' 
already  alluded-to,  which  has  its  origin  in  the  state  of  tension  of  the  muscles, 
and  which  is  no  more  an  indication  of  mental  effort  directed  to  them,  than  the 
sensation  of  light  or  sound  is  an  indication  of  a  determination  of  voluntary  power 
to  the  eyes  or  ears. 

546.  There  are  two  cases,  already  referred-to  under  another  head,  in  which  it 
is  very  easy  to  show  that  the  Will  is  concerned  with  the  result  alone,  and  is  not 
directly  exerted  upon  the  instruments  by  which  that  result  is  brought-about : 
these  are,  the  movements  of  the  Eyes,  and  the  production  of  Vocal  tones.  In 
neither  of  them  are  we  conscious  of  any  effort  in  the  muscular  apparatus,  unless 
the  contraction  be  carried  beyond  its  accustomed  extent;  the  ordinary  movements 
being  governed,  as  already  remarked,  not  by  the  muscular  sense,  but  by  the  visual 
and  auditory  senses  respectively  — Nothing  can  be  more  simple,  to  all  appearance, 
than  the  act  of  turning  the  eye-*  upwards  or  downwards,  to  one  side  or  the  other, 
in  obedience  to  a  determination  of  the  Will ;  and  yet  the  Will  does  not  impress 
such  a  determination  upon  tb •?  muscles.  That  which  the  Will  really  does,  is  to 
cause  the  eyeballs  to  roll  i»  a  given  direction,  in  accordance  with  a  visual  sensa- 
tion ;  and  it  is  only  when  there  is  an  object  towards  which  the  eyes  can  be  turned, 
that  we  can  move  them  vith  our  usual  facility.  When  the  eyelids  are  closed, 
and  we  attempt  to  roll  the  globes  upwards  or  downwards,  to  one  side  or  to  the 
other,  we  feel  that  we  can  do  so  but  very  imperfectly,  and  with  a  sense  of  effort 
referred  to  the  muscles  themselves, — this  sense  being  the  result  of  the  state  of 
tension  in  which  the  muscles  are  placed,  by  the  effort  to  move  the  eyes  without 
the  guiding  visual  sensation.  Now,  on  the  other  hand,  the  Will  may  determine 
to  fix  the  eyes  upon  an  object;  and  yet  this  very  fixation  may  be  only  attainable 
by  a  muscular  movement,  which  movement  is  directly  excited  by  the  visual  sense, 
without  any  exertion  of  voluntary  power  over  the  muscles.  Such  is  the  case 
when  we  look  steadily  at  an  object,  whilst  we  move  the  head  horizontally  from 
side  to  side;  for  the  eyeballs  will  then  be  moved  in  the  contrary  direction  by  a 
kind  of  instinctive  effort  of  the  external  and  internal  recti,  which  tends  to  keep 
the  retinae  in  their  first  position,  and  to  prevent  the  motion  of  the  images  over 
them.  So,  when  we  look  steadily  at  an  object,  and  incline  the  head  towards 
either  shoulder,  the  eyeballs  are  rotated  upon  their  antero-posterior  axis  (probably 
by  the  agency  of  the  oblique  muscles)  apparently  with  the  very  same  purpose, — 
that  of  preventing  the  images  from  moving  over  the  retinae  (see  Chap,  xin., 
Sect.  3).  Now  we  cannot  refuse  to  this  rotation  any  of  the  attributes  which 
really  characterize  the  so-called  voluntary  movements ;  and  yet  we  are  not  ever 
informed  by  our  own  consciousness  that  such  a  movement  is  taking  place,  but 
know  it  only  by  observation  of  others. 

547.  The  muscular  contractions  which  are  concerned  in  the  production  of 
Vocal  tones,  are,  in  like  manner,  always  accounted  voluntary;  and  yet  it  is  easy 
to  show  that  the  Will  has  no  direct  power  over  the  muscles  of  the  larynx.  For 


510  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

we  cannot  raise  or  depress  the  larynx  as  a  whole,  nor  move  the  thyroid  cartilage 
upon  the  ericoid,  nor  separate  or  approximate  the  arytenoid  cartilages,  nor  extend 
or  relax  the  vocal  ligaments,  by  simply  witting  to  do  so,  however  strongly.  Yet 
we  can  readily  do  any  or  all  these  things,  by  an  act  of  the  Will  exerted  for  a 
specific  purpose.  We  conceive  of  a  tone  to  be  produced,  and  we  will  to  produce 
it;  a  certain  combination  of  the  muscular  actions  of  the  larynx  then  takes  place, 
in  most  exact  accordance  with  one  another ;  and  the  predetermined  tone  is  the 
result.  This  anticipated  or  conceived  sensation  is  the  guide  to  the  muscular 
movements,  when  as  yet  the  utterance  of  the  voice  has  not  taken  place ;  but 
whilst  we  are  in  the  act  of  speaking  or  singing,  the  contractile  actions  are  regu- 
lated by  the  present  sensations  derived  from  the  sounds  as  they  are  produced. — 
It  can  scarcely  but  be  admitted,  then,  that  the  Will  does  not  directly  govern  the 
movements  of  the  Larynx;-  but  that  these  movements  are  immediately  dependent 
upon  some  other  agency. 

548.  Now  what  is  true  of  the  two  preceding  classes  of  actions,  is  equally  true 
of  all  the  rest  of  the  so-called  voluntary  movements;  for  in  each  of  them  the 
power  of  the  Will  is  really  limited  to  the  determination  of  the  result;  and  the 
production  of  that  result  is  entirely  dependent  upon  the  concurrence  of  a  '  guiding 
sensation/  which  is  usually  furnished  by  the  very  muscles  that  are  called  into 
action.     It  is  obvious,  therefore,  that  we  have  to  seek  for  some  intermediate 
agency,  which  executes  the  actions  determined  by  the  Will ;  and  when  the  facts 
and  probabilities  already  stated  are  duly  considered,  they  tend  strongly  in  favour 
of  the  idea,  that  even  Voluntary  movements  are  executed  by  the  instrumentality 
of  the  Automatic  apparatus,  and  that  they  differ  only  from  the  automatic  or  in- 
stinctive in  the  nature  of  the  stimulus  by  which  they  are  excited, — the  deter- 
mination  of  the  Will  here  replacing,  as  the  exciting  cause  of  its  action,  the 
sensory  impression  which  operates  as  such  in  the  case  of  an  instinctive  movement, 
and  which  is  still  requisite  for  its  guidance. 

549.  This  view  of  the  case  derives  a  remarkable  confirmation  from  the  analy- 
sis of  two  classes  of  very  familiar  phenomena :  the  first  consisting  of  cases  in 
which  movements  that  are  ordinarily  Automatic  are  performed  by  Voluntary 
determination,  or  simply  in   respondence  to  an  Idea;   the  second  consisting  of 
those  in  which  movements  originally  Voluntary  come  by  habit  to  be  Automati- 
cally performed. — Of  the  first  class,  the  act  of  Coughing  is  a  good  example.     This 
action,  which  is  ordinarily  automatic,  may  also  be  excited  by  a  voluntary  deter- 
mination ;  such  a  determination,  however,  is  directed  to  the  result,  rather  than 
exercised  in  singling-out  the  different  movements  and  then  combining  them  in 
the  necessary  sequence;  and  the  Will  thus  seems  obviously  to  take  the  place  of 
the  laryngeal  or  tracheal  irritation,  as  the  primum  mobile  of  the  series,  which, 
in  its  actual  performance,  is  as  automatic  in  the  latter  case  as  in  the  former.     So, 
again,  we  know  that  many  of  the  automatic  movements  which  have  been  already 
referred-to  as  examples  of  the  sensori-motor  group  (§  538),  and  which  the  Will 
cannot  call-forth,  may  be  performed  in  respondence  to  ideas  or  conceptions,  which 
are  Cerebral  states  that  seem  to  recall  the  same  condition  of  the  Sensorium  as  that 
which  was  originally  excited  by  the  Sensory  impression.     Thus  it  is  well  known 
that  the  act  of  Vomiting  may  be  induced  by  the  remembrance  of  some  loathsome 
object  or  nauseous  taste,  which  may  have  been  excited  by  some  act  of  *  sugges- 
tion ;'  and  the  author  has  known  an  instance  in  which  a  violent  fit  of  sea-sickness 
was  brought-on  by  the  sight  of  a  vessel  tossed  about  at  sea,  which  recalled  the 
former  experience  of  that  state.     So,  the  Hydrophobic  paroxysm  may  be  excited 
by  the  mention  of  the  name  of  water,  which  of  course  calls  up  the  idea ;  and  a 
tendency  to  yawn  is  in  like  manner  frequently  induced  by  looking  at  a  picture  of 
yawners,  or  by  speaking  of  the  act,  or  by  voluntarily  commencing  the  act  which 
may  then  be  automatically  completed. — The  automatic  performance  of  actions 
which  were  originally  voluntary,  has  already  been  fully  discussed  (§  540) ;  and 
we  have  therefore  only  to  remark  here,  that  the  fact  very  strongly  supports  the 


THE    CEREBELLUM,    AND    ITS    FUNCTIONS.  51 1 

view  now  advanced,  as  to  the  singleness  of  the  mechanism  which  serves  as  the 
instrument  of  both  classes  of  actions,  and  the  essential  uniformity  of  its  operation 
in  the  two  cases. — It  would  be  difficult  to  explain  either  set  of  phenomena  satis- 
factorily, on  the  hypothesis  that  there  is  a  l  distinct  system  '  of  fibres  for  the  voli- 
tional and  for  the  automatic  movements ;  since  it  is  not  readily  to  be  conceived, 
how  a  set  of  movements  originally  performed  by  the  one,  can  ever  be  transferred 
to  the  other;  whilst,  on  the  other  hand,  it  is  easy  to  understand  how  the  same 
inotorial  action  may  be  excited  in  the  automatic  centres,  either  by  an  external 
impression  conveyed  thither  by  an  afferent  nerve  from  a  Sensory  surface  (as  that 
of  the  irritation  in  the  air-passages,  which  excites  the  act  of  coughing),  or  by  a 
stimulus  proceeding  from  the  convoluted  surface  of  the  Cerebrum,  and  conveyed 
along  those  connecting  fibres  which  Reil  with  great  sagacity  termed  the  '  nerves 
of  the  internal  senses.' 

550.  To  sum-up,  then,  we  seem  justified  in  concluding  that  the  Oramo- Spinal 
Axis  of  Man  and  other  Vertebrata, — consisting  of  the  Sensory  Ganglia,  Medulla 
Oblongata,  and  Spinal  Cord, — is  (like  the  chain  of  cephalic  and  ventral  ganglia 
of  Articulata  with  which  it  is  homologous)  the  immediate  instrument  of  all  sen- 
sorial  and  motor  changes  ;  that  by  its  sole  and  independent  action  are  produced 
all  those  movements  which  are  ranked  as  automatic  or  instinctive,  these  being 
performed  in  respondence  to  external  impressions  which  may  or  may  not  affect 
the  consciousness ;  but  that  when  acting  in  subordination  to  the  Cerebrum,  the 
Cranio-Spinal  Axis  transmits  upwards  to  it  the  influence  of  Sensorial  changes, 
and  receives  from  it  the  downward  impulses,  which  it  directs  automatically  into 
the  appropriate  channel  for  the  execution  of  the  movements  which  the  Mind  has 
directed.  The  number  of  purely-automatic  actions  diminishes  in  proportion  to 
the  development  of  the  Cerebrum,  and  to  the  subjection  of  the  Automatic  appa- 
ratus to  its  control ;  but  even  in  Man,  those  most  closely  connected  with  the 
maintenance  of  the  organic  functions,  or  most  necessary  for  the  conservation  of 
the  bodily  structure,  remain  quite  independent  of  any  mental  agency,  and  most 
of  them  do  not  require  consciousness  for  their  excitation.  But  if  the  activity 
of  the  Cerebrum  be  suspended  or  be  otherwise  directed,  without  any  affection  of 
the  automatic  apparatus,  movements  which  have  long  been  habitually  performed 
in  a  particular  sequence,  may  be  kept-up,  when  the  will  has  once  set  them  in 
action,  through  the  automatic  mechanism  alone ;  the  impressional  or  sensational 
change  produced  by  each  action,  supplying  the  stimulus  which  calls-forth  the 
next. — It  may  further  be  concluded,  that  the  Sensory  Ganglia,  which  are  the 
instruments  whereby  we  are  rendered  conscious  of  external  impressions,  are  also 
the  seat  of  those  simple  feelings  of  pleasure  and  pain,  which  are  immediately 
liuked-on  to  that  consciousness  :  for  it  can  scarcely  be  doubted  that  such  feelings 
must  be  associated  with  particular' sensations,  in  animals  that  have  no  ganglionic 
centres  above  these;  since  we  must  otherwise  regard  the  whole  series  of  Inverte- 
brated  tribes  as  neither  susceptible  of  enjoyment,  nor  capable  of  feeling  pain  or 
discomfort.  And  it  likewise  seems  probable  that  the  Sensory  Ganglia  are  also 
the  seat  of  those  perceptional  acts,  which  bring  the  consciousness  into  direct 
relation  with  the  external  object  that  aroused  the  sensation  (Sect.  6);  since 
the  recognition  of  externality  seems  evident  in  the  actions  of  the  tribes  just 
referred-to. 

4.    Of  the  Cerebellum,  and  its  Functions. 

551  The  Cerebellum  is  an  organ  which,  though  confined  to  the  Vertebrate*! 
pub-Kingdom,  is  yet  in  peculiarly  intimate  relation  with  the  Automatic  appara- 
tus. In  that  highest  state  of  development  which  it  presents  in  Man,  we  find  it 
to  consist  of  two  lateral  lobes  or  hemispheres,  (Fig.  146),  composed  of  nerve- 
fibres  invested  in  a  very  peculiar  manner  by  vesicular  substance,  and  of  a  central 
lobe,  also  containing  a  combination  of  the  vesicular  and  fibrous  substances,  which 
is  known  under  the  designation  of  the  '  vermiform  process.'  The  hemispheres 


FUNCTIONS   OF    THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 
[Fie.  116. 


An  under  view  of  the  cerebellum,  seen  from  behind. — The  medulla  oblongata,  m,  having  been 
snt  off  a  short  way  below  the  pons.  (Reil.)  c.  Pons  Varolii.  <i  Middle  crus  of  cerebellum.  «, 
e.  Crura  cerebri.  i.  Notch  on  posterior  border,  k.  Commencement  of  horizontal  fissure.  L  Floc- 
3ulus,  or  sub-peduncular  lobe.  m.  Medulla  oblongata  cut  through,  q  to  s.  The  inferior  vermiform 
process,  lying  in  the  vallecula.  ^.Pyramid,  r.  Uvula,  n,  n.  Amygdalae,  s.  Nodule,  or  laminated 
tubercle,  a;.  Posterior  velum,  partly  seen.  to.  Right  and  left  hemispheres  of  cerebellum.  3  to  7. 
Nerves.  3  3.  Motores  oculorum.  5.  Trigeminal.  6.  Abducent  nerve.  7.  Facial  and  auditory  nerves.] 


Analytical  diagram  •  f  '  V  .  "/rfp'.^.oD  — in  a  vertical  section.  (After  Mayo.) — s.  Spinal  Cord. 
r.  Restiform  bodies  passing  ,o  <e,  dbe  cerebellum,  d.  Corpus  dentatum  of  the  cerebellum,  o.  Oli- 
vary body.  /.  Columns  cc^tirinous  v.  ith  the  olivary  bodies  and  central  part  of  the  medulla  ob- 
longata, and  ascending  to  the  tubercula  quadrigemina  and  optic  thalami.  p.  Anterior  pyramids. 
p.  Pons  Varolii.  n,  b.  Tubercula  quadrigemina.  g.  Geniculate  body  of  the  optic  tbalamus.  t. 
Processus  cerebelli  ad  testes.  a.  Anterior  lobe  of  the  brain,  q.  Posterior  lobe  of  the  brain.] 


THE    CEREBELLUM,    AND    ITS    FUNCTIONS. 


513 


are  connected  with  each  other  not  only  by  this  central  lobe,  but  also  by  the 
fibrous  commissure  which  passes  beneath  the  Medulla  Oblongata,  and  is  known 
as  the  '  Pons  Varolii/  The  commissural  fibres  form  part  of  the  '  Crura  Cere- 
belli ;'  but  another  portion  is  formed  by  the  strands  which  connect  the  Cerebel- 
lum with  the  anterior  and  posterior  columns  of  the  Spinal  Cord  and  Medulla 
Oblongata,  (Fig.  147),  (§  489) ;  and  in  addition  to  these,  we  find  a  fasciculus 
of  fibres  passing  between  the  Cerebellum  and  the  Corpora  Quadrigemina,  the 
'  iter  a  cerebello  ad  testes/  The  peduncle  of  its  hemispheres  on  either  side  con- 
tains a  mass  of  grey  matter,  the  '  corpus  rhomboideum/  or  'dentatum/  whir,h 
seems  to  be  a  ganglionic  centre  for  the  fibres  that  pass  upwards  to  it  from  the 
Spinal  Cord.  The  Cerebellum  has  no  direct  connection  with  the  Cerebrum,  aiid 
its  relations  are  entirely  with  the  Cranio-Spinal  Axis.  (Fig.  148). 

[FiG.  148. 


This  figure  exhibits  those  fibres  from  the  anterior  columns  which,  ascending  to  the  cere- 
bellum, connect  the  motor  tract  with  that  portion  of  the  cerebral  mass.  E.  Cerebellum,  x. 
Pons  Varolii.  T.  Pyramidal  eminences,  s.  Olivary  bodies,  w,  w.  Corpus  restiforme,  its  sur- 
face having  been  carefully  scraped  in  order  to  show  the  superficial  cerebellar  fibres  of  the 
anterior  columns.  They  are  represented  rather  more  distinct  and  thick  than  they  really  ap- 
pear, though  their  course,  direction,  and  relation  to  the  olivary  body  are  faithfully  given.-  ED.  ] 

552.  When  we  examine  into  the  relative  development  of  the  Cerebellum  in 
the  different  classes  of  Vertebrata,  we  find  that  it  presents  some  very  remarkable 
differences.1  In  its  simpler  forms,  this  organ  is  found  to  consist  entirely  of  the 

1  See  "  Princ.  of  Comp.  Phys.,"  Am.  Ed.,  $  685. — Fuller  information  upon  this  point  mill 
be  found  in  M.  Serres'  "Anat.  Comp.  du  Cerveau,"  and  M.  Leuret's  "  Anat.  Comp.  du 
Systeme  Nerveux." — For  a  general  discussion  of  the  evidence  afforded  by  Comparative 
A'natomy  in  regard  to  the  functions  of  the  Cerebellum,  see  the  "  Brit,  and  For.  Mai.  Rev.,' 
?ol.  xxii.  pp.  535 — 541. 
33 


514  FUNCTIONS   OF    THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

representative  of  the  central  lobe  of  the  Human  Cerebellum,  the  hemispheres 
not  making  their  appearance  until  we  have  ascended  to  the  class  of  Birds.  On 
ascending  the  scale  of  Mammiferous  animals,  on  the  other  hand,  we  cannot  but 
be  struck  with  the  rapid  advance  in  the  proportional  size  of  the  Cerebellum, 
which  we  observe  as  we  rise  from  the  lowest  (which  are  surpassed  in  this  respect 
by  many  Birds)  towards  Man,  in  whom  it  attains  a  development  which  appears 
enormous,  even  when  contrasted  with  that  of  the  Quadrumana.  In  proportion, 
in  fact,  as  the  extremities  acquire  the  power  of  prehension,  and  together  with 
this  a  power  of  application  to  a  great  variety  of  purposes,  still  more,  in  propor- 
tion as  the  animal  becomes  capable  of  maintaining  the  erect  posture,  in  which  a 
constant  muscular  exertion,  consisting  of  a  number  of  most  elaborately-combined 
actions,  is  required, — do  we  find  the  size  of  the  Cerebellum,  and  the  complexity 
of  its  structure,  undergoing  a  rapid  increase.  Thus,  even  between  the  Dog  and 
the  Bear  there  is  a  marked  difference ;  the  latter  being  capable  of  remaining  for 
some  time  in  the  erect  posture,  and  often  spontaneously  assuming  it;  whilst  to 
the  former  it  is  anything  but  natural.  In  the  semi-erect  Apes,  again,  there  is  a 
very  great  advance  in  the  proportional  size  of  the  Cerebellum;  and  those  which 
most  approach  Man  in  the  tendency  to  preserve  habitually  the  erect  posture,  also 
come  nearest  to  him  in  the  dimensions  of  this  organ.  —  Thus,  on  looking  at  the 
size  of  the  Cerebellum,  in  relation  to  the  general  motor  activity  of  the  Verte- 
brated  classes  respectively,  and  especially  taking  into  account  the  variety  of  their 
respective  movements,  and  the  number  of  separate  muscular  actions  which  are 
combined  in  each,  we  can  scarcely  help  noticing  that  it  is  in  the  tribes  which  are 
most  distinguished  in  these  respects,  that  the  largest  Cerebellum  is  usually  found. 
Now  it  is  evident  that  Man,  although  far  inferior  to  many  of  the  lower  animals 
in  the  power  of  performing  various  particular  kinds  of  movement,  far  surpasses 
them  all  in  the  number  and  variety  of  the  combinations  which  he  is  capable  of 
executing,  and  in  the  complexity  of  the  combinations  themselves.  Thus,  if  we 
attentively  consider  the  act  of  walking,  we  shall  find  that  there  is  scarcely  a 
muscle  of  the  trunk  or  extremities  which  is  not  actively  concerned  in  it ;  some 
being  engaged  in  performing  the  necessary  movements,  and  others  in  maintaining 
the  equilibrium  of  the  body  which  is  disturbed  by  them.  On  the  other  hand,  in 
the  Horse  or  Camel,  the  muscular  movements  are  individually  numerous,  but 
they  do  not  require  nearly  the  same  perfect  co-ordination.  And  in  the  Bird,  the 
number  of  muscles  employed  in  the  movements  of  flight,  and  in  directing  the 
course  of  these,  is  really  comparatively  small ;  as  may  at  once  be  perceived,  by 
comparing  the  rigidity  of  the  skeleton  of  the  trunk  of  the  Bird  with  that  of 
Man,  and  by  remembering  the  almost  complete  inactivity  of  the  lower  extremi- 
ties during  the  active  condition  of  the  upper.  In  fact,  the  motions  of  the  wings 
are  so  simple  and  regular,  as  to  suggest  the  idea  that,  as  in  Insects,  their  cha- 
racter is  more  reflex  than  voluntary  : — an  idea  which  is  supported  by  the  length 
of  time  during  which  they  can  be  kept-up  without  apparent  fatigue,  and  also  by 
the  important  facts  already  mentioned  (§  529),  which  experimental  research  has 
disclosed. 

553.  We  have  next  to  inquire  what  evidence  can  be  drawn  from  Experimental 
investigations  on  the  same  subject:  and  in  reference  to  this  it  is  desirable  to 
remark,  in  the  first  place,  that  the  experimental  mode  of  inquiry  is  perhaps  more 
applicable  to  this  organ  than  to  other  parts  of  the  Encephalon ;  inasmuch  as  it 
can  be  altogether  removed,  with  little  disturbance  of  the  actions  immediately  es- 
sential to  life;  and  the  animals  soon  recover  from  the  shock  of  the  operation,  and 
seem  but  little  affected,  except  in  some  easily-recognized  particulars.  The  prin- 
cipal experimenters  upon  this  subject  have  been  Orlando,  Flourens,  Magendie, 
Hertwig,  and  Longet.  It  is  not  to  be  expected,  that  there  should  be  an  exact 
conformity  among  the  results  obtained  by  all.  Every  one  who  has  been  engaged 
in  physiological  experiments,  is  aware  of  the  amount  of  difference  caused  by 
very  minute  variations  in  their  circumstances;  in  no  department  of  inquiry  is 


THE    CEREBELLUM,    AND    ITS    FUNCTIONS.  515 

this  more  the  case,  than  in  regard  to  the  Nervous  System ;  and  such  differences 
are  yet  more  likely  to  occur  in  experiments  made  upon  its  centres,  than  in  those 
which  concern  its  trunks.  —  The  investigations  of  Flourens '  are  the  most  clear 
and  decisive  in  their  results;  and  of  these  we  shall  accordingly  take  a  general  ? 
survey.  He  found  that,  when  the  Cerebellum  was  mechanically  injured,  the  ani- 
mals gave  no  signs  of  sensibility,  nor  were  they  affected  with  convulsions  When 
the  Cerebellum  was  being  removed  by  successive  slices,  the  animals  became  restless, 
and  their  movements  were  irregular  ;  and  by  the  time  that  the  last  portion  of  the 
organ  was  cut-away,  the  animals  had  entirely  lost  the  power  of  springing,  flying, 
walking,  standing,  and  preserving  their  equilibrium,  —  in  short,  of  performing 
any  combined  muscular  movements,  which  are  not  of  a  simply-reflex  character. 
When  an  animal  in  this  state  was  laid  upon  the  back,  it  could  not  recover  its 
former  posture ;  but  it  fluttered  its  wings  and  did  not  lie  in  a  state  of  stupor. 
When  placed  in  the  erect  position,  it  staggered  and  fell  like  a  drunken  man,  — 
not,  however,  without  making  efforts  to  maintain  its  balance.  When  threatened 
with  a  blow,  it  evidently  saw  it,  and  endeavoured  to  avoid  it.  It  did  not  seem 
that  the  animal  had  in  any  degree  lost  voluntary  power  over  its  several  muscles ; 
nor  did  sensation  appear  to  be  impaired.  The  faculty  of  combining  the  actions 
of  the  muscles  in  groups,  however,  was  completely  destroyed;  except  so  far  as 
those  actions  (as  that  of  Respiration,  were  dependent  only  upon  the  reflex  func- 
tion of  the  Spinal  Cord.  The  experiments  afforded  the  same  results,  when  made 
upon  each  class  of  Vertebrated  animals ;  and  they  have  been  since  repeated, 
with  corresponding  effects,  by  Bouillaud  and  Hertwig.  The  latter  agrees  with 
Flourens,  also,  in  stating  that  the  removal  of  one  side  of  the  Cerebellum  affects 
the  movements  of  the  opposite  side  of  the  body ;  and  he  further  mentions  that, 
if  the  mutilation  of  the  Cerebellum  have  been  partial  only,  its  function  is  in 
great  degree  restored.2 

554.  It  was  further  affirmed  by  Magendie,  that  the  removal  of  the  Cerebellum, 
or  the  infliction  of  a  deep  wound  in  its  substance  on  both  sides,  occasions  the 
animal  to  move  backwards  as  if  by  an  irresistible  impulse  ;  and  this  he  attributed 
to  the  retrograde  power  of  the  Corpora  Striata,  which  now  act  without  their  due 
balance.  That  such  a  movement  does  sometimes  present  itself  after  such  injuries 
as  have  been  described,  cannot  be  questioned,  the  fact  having  been  confirmed  by 
other  experimenters ;  but  it  is  a  phenomena  of  such  rarity,  that  it  cannot  be 
rightly  considered  as  having  any  direct  dependence  upon  the  injury  of  the  Cere- 
bellum, but  must  be  rather  set-down  to  some  accidental  complication,  or  concur- 
rent disturbance ;  more  especially  since,  as  already  pointed-out  (§  533),  the  func- 
tion attributed  by  Magendie  to  the  Corpora  Striata  has  no  real  existence. — But 
the  results  of  section  of  one  of  the  Crura  Cerebelli,  which  were  first  obtained  by 
Magendie,  are  much  more  constant ;  for  the  performance  of  this  operation  causes 
the  animal  to  fall-over  upon  one  side,  and  to  continue  rolling  upon  its  longitudi- 
nal axis,  even  as  fast  (in  some  instances)  as  sixty  times  in  a  minute ;  the  move- 
ment going-on  for  many  days  without  intermission.  There  is  a  remarkable  dif- 
ference in  the  statements  of  different  experimenters,  however,  as  regards  the 
direction  of  this  rolling  movement;  for  whilst  Magendie  and  Miiller  affirm  that 
it  takes  place  towards  the  injured  side,  Longet  and  Lafargue  assert  that  it  takes 
place  from  the  injured  side  towards  the  opposite  side.  This  discrepancy  appears, 
from  the  experiments  of  Schiff,3  to  be  due  to  a  difference  in  the  locality  of  the 
*  "  Recherches  Expe'rim.  sur  les  propriete's  etles  fonctions  du  Systeme  Nerveux." 
a  All  these  results  are  objected- to  by  those  who  assert  that  the  Cerebellum  is  the  seat  of 
the  sexual  instinct,  on  the  ground  that  the  observed  aberrations  of  the  motor  functions  are 
sufficiently  accounted-for,  by  the  general  disturbance  which  an  operation  so  severe  must 
necessarily  induce.  The  fallacy  of  this  objection,  however,  is  shown  by  the  fact,  that  the 
much  more  severe  operation  of  removing  the  Hemispheres  does  not  occasion  such  an  aber- 
ration; the  power  of  performing  the  associated  movements  and  of  maintaining  the  equi- 
librium; being  remarkably  preserved  after  the  loss  of  them  (%  529). 

'  "  De  vi  motoria,  baseos  eacephali  inquisitiones  experimeutales ;"  Bockenhemii,  1845 


516  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

section;  for  he  states  that  if  the  peduncle  be  divided  from  behind,  the  aninrij 
turns  towards  the  side  on  which  the  section  is  made ;  whilst  if  the  section  be 
made  in  front,  the  animal  turns  from  that  side  towards  the  opposite  one.  This 
difference  is  explained  by  Longet,  by  the  difference  in  the  course  of  the  anterior 
and  posterior  fibres  of  the  peduncles  :  for  according  to  him,  the  former  commu- 
nicate with  the  decussating,  and  the  latter  with  the  non-decussating  portion  of  the 
motor  tract;  so  that,  when  the  former  are  injured,  the  animal  loses  control  over 
the  muscles  of  the  opposite  side,  and  when  the  latter,  over  the  muscles  of  the 
same  side.  This  rolling  movement  is  attributed  by  some  to  the  continued  activity 
of  the  muscles  on  one  side,  now  unbalanced  by  that  of  the  muscles  on  the  other ; 
but  if  such  were  the  case,  as  Longet  justly  remarks,  it  ought  to  occur  more  fre- 
quently than  it  does  in  cases  of  ordinary  hemiplegia;  and,  according  to  that 
experimenter,  observation  shows  that  it  rather  depends  on  a  twisting  movement 
of  the  spinal  column,  especially  affecting  its  anterior  portion,  and  dragging  the 
posterior  (as  it  were)  after  it.1 

555.  The  information  supplied  by  Pathological  phenomena,  when  interpreted 
with  the  cautions  formerly  referred-to,  is  found  on  the  whole  to  coincide  with  that 
obtained  from  experiment.  In  the  first  place,  it  fully  supports  the  conclusion, 
that  the  Cerebellum  is  not  in  any  way  the  instrument  of  psychical  operations. 
Inflammation  of  the  membranes  covering  it,  if  confined  to  that  part,  does  not 
produce  delirium,  and  its  almost  complete  destruction  by  gradual  softening,  does 
not  appear  necessary  to  involve  loss  of  intellectual  power.  "But,"  remarks  An- 
dral,  "  whilst  the  changes  of  intelligence  were  variable,  inconstant,  and  of  little 
importance,  the  lesions  of  motion,  on  the  contrary,  were  observed  in  all  the  cases 
[of  softening]  except  one ;  and  in  this  it  is  not  quite  certain  that  motion  was  not 
interfered  with."  Yet  the  result  of  Andral's  analysis  of  as  many  as  ninety-three 
cases  of  disease  of  the  Cerebellum,2  is  not  favourable  to  the  doctrine  to  which 
the  results  of  experiments  seem  to  point;  but,  as  it  has  been  justly  remarked  by 
Longet,  the  effects  of  disease  are  only  partly  comparable  to  those  of  experiment ; 
since  in  a  large  proportion  of  chronic  disorders,  the  changes  consist  in  the  for- 
mation of  a  new  product,  such  as  a  tubercular  or  cancerous  deposit,  or  a  cyst  of 
some  kind,  the  gradual  development  of  which  is  quite  consistent  with  the  con- 
tinued functional  activity  of  the  organ,  as  we  see  by  parallel  phenomena  elsewhere ; 
whilst  in  those  instances  in  which  haemorrhage  occurs,  this  usually  occasions 
either  complete  apoplexy  or  local  paralysis,  by  its  effects  upon  other  organs.  Still, 
several  cases  of  chronic  disease  of  the  Cerebellum  have  been  observed,  in  which 
unsteadiness  of  gait,  without  paralysis,  or  only  giving  place  to  paralysis  at  last  on 
the  occurrence  of  hemorrhage,  was  a  very  marked  symptom;3  and  these  afford  a 
strong  confirmation  of  the  doctrine  based  on  the  experimental  researches  already 
referred-to.  In  a  few  cases  in  which  both  lobes  of  the  Cerebellum  have  been 
seriously  affected,  the  tendency  to  retrograde  movement  has  been  observed ;  and 
instances  are  also  on  record  of  the  occurrence  of  rotatory  movement,  which  has 
been  found  to  be  connected  with  lesion  of  the  Crus  Cerebelli  on  the  same  side.4 
So  far  as  they  can  be  relied-on,  therefore,  the  results  of  the  three  methods  of  in- 
vestigation bear  a  very  close  correspondence  ;  and  it  can  scarcely  be  doubted  that 
they  afford  us  a  near  approximation  to  truth. 

1  See  his  "  Traits'  de  Physiologic,"  torn,  ii.,  partie  2,  pp.  216,  217. 

a  See  his  "  Clinique  M<§dicale,"  2ieme  edit.  torn.  v.  p.  735. 

*  Two  such  cases  are  recorded  by  Mr.  Dunn  in  the  "  Med.-Chir.  Trans.,"  vol.  xxxii. ; 
and  another  by  Dr.  Cowan  in  the  "Prov.  Med.  and  Surg.  Journ.,"  April  16,  1845;  and 
the  Author  has  been  made  acquainted  with  several  others,  by  gentlemen  under  whose  cog- 
nisance they  have  fallen. 

4  A  collection  of  such  cases  has  been  made  by  Dr.  Paget,  in  his  paper  on  "  Morbid 
Rhythmical  Movements,"  in  the  "Edinb.  Med.  and  Surg.  Journal,"  1847,  vol.  Ixvii. — A 
case  fell  within  the  Author's  knowledge  a  few  years  ago,  in  which  a  state  of  this  kind, 
that  lasted  for  some  hours,  appeared  to  depend  upon  an  attack  of  Indigestion ;  the  syrnp 
toms  being  completely  relieved  by  vomiting,  and  no  further  indication  of  Encephalic  dis 
order  manifesting  itself. 


THE    CEREBELLUM,    AND    ITS    FUNCTIONS.  517 

556-  It  must  not  be  allowed  to  pass  unnoticed,  that  some  Physiologists  (as 
Foville,  Pinel-Grandchamp,  and  Duges)  have  regarded  the  Cerebellum  as  the 
centre  of  common  Sensation ;  chiefly  on  the  ground  of  its  connection  with  the 
posterior  columns  of  the  Spinal  Cord,  and  of  the  manifestations  of  pain  which  are 
Balled-forth  by  touching  the  Restiform  columns.  Although  these  facts  may  lead 
us  to  admit  that  the  Cerebellum  is  connected  with  the  sensorial  centres,  and  even 
that  it  is  itself  a  seat  of  sensibility,  yet  it  is  impossible  to  regard  it  as  the  exclu- 
sive seat  of  sensibility,  consistently  with  the  facts  with  which  experiment  and 
pathological  observation  supply  us ;  since  neither  the  removal  of  the  entire  organ 
by  operation,  nor  its  complete  destruction  by  disease,1  have  been  found  to  involve 
any  loss  of  the  ordinary  seusorial  powers. — There  would  seem  much  more  proba- 
bility in  the  idea,  that  it  is  the  special  seat  of  the '  muscular  sense/  which  has  so 
important  a  share  in  the  guidance  of  the  co-ordinated  movements  (§  541);  and 
this  notion  derives  confirmation,  from  the  marked  structural  connection  which 
exists  between  the  Cerebellum  and  the  Optic  Ganglia  (corpora  quadrigemina), 
the  purpose  of  which  may  be  not  unfairly  surmised  to  be,  to  communicate  the 
guidance  of  the  visual  sense  to  the  organ  by  which  the  co-ordination  of  motions  is 
effected,  in  the  same  manner  as  the  impressions  appertaining  to  the  '  muscular 
sense'  are  transmitted  upwards  by  the  Restiform  columns.  The  chief  objection 
to  such  a  view,  would  seem  to  lie  in  the  strong  similarity  between  the  '  muscular' 
sense  and  'common'  or  < tactile'  sensation,  which  makes  it  difficult  to  conceive 
that  they  should  have  different  seats  in  the  S?nsorium  commune.  But  this  diffi- 
culty is  diminished  if  not  removed  by  the  reflection,  that  the  Restiform  columns 
appear  to  have  the  same  endowments  as  the  remainder  of  the  Sensory  tract  de- 
rived from  the  posterior  columns  of  the  Spinal  Cord ;  and  that  no  explanation 
can  be  given  of  their  extreme  sensitiveness  to  impressions  (as  shown  by  experi- 
ment), unless  it  be  admitted  that  the  organ  in  which  they  terminate  is  itself  a 
centre  of  a  form  of  sensation  closely  allied  to  that  of  the  common  or  tactile  kind. 
Possibly,  however,  the  true  termination  of  these  fibres  is  in  the  '  corpus  denta- 
tum '  of  the  Crura  Cerebelli ;  and  the  Cerebellum  may  re-act  upon  impressions 
thence  transmitted  to  it,  without  being  itself  the  instrument  of  communicating 
such  impressions  to  the  consciousness. 

557.  We  have  now  to  examine,  however,  another  doctrine  regarding  the  func- 
tions of  the  Cerebellum,  which  was  first  propounded  by  Gall,  and  which  is  sup- 
ported by  the  Phrenological  school  of  physiologists.  This  doctrine,  that  the 
Cerebellum  is  the  organ  of  the  sexual  instinct,  is  not  altogether  incompatible  with 
the  other;  and  by  some  it  has  been  held  in  combination  with  it.  The  greater 
number  of  Phrenologists,  however,  regard  this  instinct  as  the  exclusive  function 
of  the  Cerebellum ;  and  assert  that  they  can  judge  of  its  intensity  by  the 
degree  of  the  development  of  the  organ.  We  shall  now  examine  the  evidence 
in  support  of  this  position  afforded  by  the  three  methods  of  inquiry  which  have 
been  already  indicated.  In  the  first  place  it  may  be  remarked,  that  the  sexual 
propensity  is  very  closely  connected  with  various  Emotional  states  of  mind,  to 
which  l organs'  are  assigned  by  Phrenologists,  and  of  which  the  Cerebrum  is 
universally  admitted  to  be  the  seat ;  such  for  instance  as  ( love  of  offspring/ 
'  adhesivness/  and  (in  the  lower  animals  more  particularly)  '  combativeness ;' 
whilst  in  Man  it  has  a  continual  operation  upon  the  reasoning  faculties  and  the 
Will.  Yet  the  anatomical  connections  of  the  Cerebellum  are  peculiarly  unfavor- 
able to  any  such  influence ;  these  being,  as  we  have  seen  rather  with  the  lower 
than  with  the  higher  portion  of  the  Cerebro-spinal  axis. — Again,  the  results  of 
fciir  observation  as  to  the  comparative  size  of  the  Cerebellum  in  different  animals, 
can  scarcely  be  regarded  as  otherwise  than  very  unfavourable  to  the  doctrine  to 
question.2 — it  is  asserted,  however,  that  the  results  of  observation  in  Man  lead 

1  See  the  well-known  case  recorded  by  Combetti,  in  the  "  Revue  Me"dicale,"  totn.  iL 
p.  57 

a  See  "Brit,  and  For.  Medical  Review,"  vol.  xxii.  pp.  535-541. 


518  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

to  a  positive  conclusion,  that  the  size  of  the  Cerebellum  is  a  measure  of  the 
intensity  of  the  sexual  instinct  in  the  individual.  This  assertion  has  been  met 
by  the  counter-statement  of  others,  that  no  such  relation  exists.  It  is  unfor- 
tunate that  here,  as  in  many  other  instances,  each  party  has  registered  the  obser- 
vations favourable  to  its  own  views,  rather  than  those  of  an  opposite  character; 
so  that  until  some  additional  evidence  of  a  less  partial  nature  shall  have  been 
collected,  we  must  consider  the  question  as  sub  judice.  It  may  be  safely  affirmed, 
however,  that  no  evidence  upon  the  affirmative  side  of  this  proposition  has  yet 
been  adduced,  which  can  be  in  the  least  degree  satisfactory  to  the  mind  of  any 
Anatomist  who  is  competent  to  judge  of  its  value.  For  nearly  all  the  observa- 
tions which  have  been  paraded  by  Phrenologists  in  support  of  Gall's  doctrine, 
have  been  based,  not  upon  the  actual  determination  of  the  size  or  weight  of  the 
Cerebellum  in  different  individuals,  but  upon  an  estimate  of  its  proportional 
development  from  the  external  conformation  of  the  skull.  Now  any  one  who 
has  even  cursorily  examined  those  principal  types  of  cranial  conformation,  which 
are  characteristic  of  some  of  the  chief  subdivisions  of  the  Human  species,  must 
perceive  that  there  is  a  no  less  characteristic  difference  between  these  different 
types  in  the  occipital,  than  there  is  in  the  frontal  region.  For  whilst  the 
occipital  projection  is  much  greater  in  the  <  prognathous '  skull  than  it  is  in  the 
'  elliptical/  it  is  as  much  less  in  the  '  pyramidal  •/  and  thus  while  the  first  would 
be  considered,  according  to  the  phrenological  rules,  to  hold  a  much  larger  Cere- 
bellum, this  organ  in  the  latter  would  be  regarded  as  necessarily  very  small. 
Now  there  is  not  only  as  much  evidence  of  a  strong  development  of  the  sexual 
propensity,  in  the  characters  and  habits  of  the  pyramidal-skulled  Asiatics,  as 
there  is  in  regard  to  the  elliptical-skulled  Europeans,  or  the  prognathous  Negroes ; 
but  there  is  also  anatomical  evidence  to  show  that  the  size  of  the  Cerebellum  in 
the  different  races  bears  no  relation  whatever  to  the  degree  of  projection  of  the 
occiput;  for  the  plane  of  this  organ  being  somewhat  oblique  in  the  elliptical 
skull,  is  horizontal  in  the  prognathous,  and  nearly  vertical  in  the  pyramidal, 
while  the  size  and  anatomical  relations  of  the  organ  are  not  in  the  least  degree 
affected  by  this  difference  in  its  position.1 — Hence  it  may  be  safely  affirmed,  that 
no  evidence  with  regard  to  the  relation  asserted  to  exist  between  the  size  of  the 
Cerebellum  and  the  intensity  of  the  sexual  propensity,  has  any  value,  save  that 
which  is  drawn  from  the  positive  determination  of  the  former  by  measure  or 
weight. 

558.  Among  the  arguments  adduced  by  Gall  and  his  followers  in  proof  of  the 
connection  between  the  Cerebellum  and  the  sexual  instinct  is  one  which  would 
deserve  great  attention,  if  the  facts  stated  could  be  relied-on.  It  has  been 
asserted,  over  and  over  again,  that  the  Cerebellum,  in  animals  which  have  been 
castrated  when  young,  is  much  smaller  than  in  those  which  have  retained  their 
virility, — being,  in  fact,  atrophied  from  want  of  power  to  act.  Now  it  is  unfor- 
tunate that  vague  assertion,  founded  on  estimates  formed  by  the  eye  from  the 
cranium  alone,  is  all  on  which  this  position  rests ;  and  it  will  be  presently  shown 
how  very  liable  to  error  such  an  estimate  must  be.  The  following  is  the  result 
of  a  series  of  observations  on  this  subject,  suggested  by  M.  Leuret,2  and  carried 
into  effect  by  M.  Lassaigne  : — The  weight  of  the  Cerebellum,  both  absolutely,  and 
as  compared  with  that  of  the  Cerebrum,  was  adopted  as  the  standard  of  comparison. 
This  was  ascertained  in  ten  Stallions,  of  the  ages  of  from  nine  to  seventeen  years ;  in 
twelve  Mares,  aged  from  seven  to  sixteen  years;  and  in  twenty-one  Geldings,  aged 
from  seven  to  seventeen  years.  The  average  weight  of  the  Cerebrum  in  the  Stal- 
lions was  433  grammes  ;  the  greatest  being  485  gr.,  and  the  least  (which  was  in  a 
house  of  ten  years  old)  being  350  gr.  The  average  weight  of  the  Cerebellum  was  61 
gr. ;  the  greatest  being  65  gr.,  the  least  56  gr.  The  average  proportion  borne  l>y 

1  The  Author's  statements  on  this  point  are  based  on  the  very  decided  assertions  of  his 
friend  Prof.  Retzius  of  Stockholm,  who  has  paid  special  attention  to  this  inquiry. 
a  "  Anat.  Comp.  du  Systeme  Nerveux,"  torn.  i.  p.  427. 


AND    ITS    FUNCTIONS.  519 

(he  weight  of  the  Cerebellum  to  that  of  the  Cerebrum,  was,  therefore,  one  1  to  7-07 ; 
the  highest  (resulting  from  alvery  small  Cerebrum)  being  1  to  6-25;  and  the 
lowest  (resulting  from  an  unusually  large  Cerebrum)  being  1  to  746.  Through- 
out it  might  be  observed,  that  the  variation  in  the  size  of  the  Cerebellum  was 
much  less  than  in  that  of  the  Cerebrum. — In  the  twelve  Mares  the  average  weight 
of  the  Cerebrum  was  402  gr. ;  the  highest  being  432  gr.,  and  the  lowest  363  gr. 
That  of  the  Cerebellum  61  gr.  ;  the  highest  being  66  gr.  (which  was  in  the 
individual  with  the  smallest  Cerebrum),  and  the  lowest  58  gr.  The  average  pro- 
portion of  the  weight  of  the  Cerebellum  to  that  of  the  Cerebrum  was  1  to  6-59 ; 
the  highest  being  1  to  5-09,  and  the  lowest  1  to  7.  The  proportion  was,  there- 
fore, considerably  higher  in  the  perfect  female,  than  in  the  perfect  male. — In  the 
twenty-one  Geldings,  the  average  weight  of  the  Cerebrum  was  419  gr. ;  the 
highest  being  566  gr.,  and  the  lowest  346  gr.  The  average  of  the  Cerebellum 
was  70  gr.,  the  lowest  being  76  gr.,  and  the  lowest  64  gr.  The  average  propor- 
tion was,  therefore,  1  to  5-97;  the  highest  being  1  to  5-16,  and  the  lowest  1  to  744. 
It  is  curious  that  this  last  was  in  the  individual  which  had  the  largest  Cerebel- 
lum of  the  whole ;  but  the  proportional  weight  of  the  Cerebrum  was  still  greater. — 
Bringing  together  the  results  of  these  observations,  they  are  found  to  be  quite  op- 
posed to  the  statement  of  Gall.  The  weight  of  the  Cerebrum,  reckoning  the  Cere- 
bellum as  1,  is  thus  expressed  in  each  of  the  foregoing  descriptions  of  animals  : — 

Average.  Highest.  Lowest. 

Stallions 7-07  7-46  6-25 

Mares 6-59  7-00  5.09 

Geldings 5-97  7-44  5-16 

The  average  proportional  size  of  the  Cerebellum  in  Geldings,  therefore,  is  so  far 
from  being  less  than  that  which  it  bears  in  entire  Horses  and  Mares,  that  it  is 
positively  greater;  and  this  depends  not  only  on  diminution  in  the  relative  size 
of  the  Cerebrum,  but  on  its  own  larger  dimension,  as  the  following  comparison 
of  absolute  weights  will  show  : — 

Average.  Highest.  Lowest. 

Stallions 61  65  56 

Mares 61  66  58 

Geldings 70  76  64 

The  difference  is  so  remarkable,  and  appears,  from  examination  of  thts  individual 
results,  to  be  so  constant,  that  it  cannot  be  attributed  to  any  accidental  circum- 
stance, arising  out  of  the  small  number  of  animals  thus  examined.  The  average 
weight  of  the  Cerebellum  in  the  ten  Stallions  and  twelve  Mares,  is  seen  to  be  the 
same,  and  the  extremes  differ  but  little  in  the  'two ;  whilst  the  average  in  the 
Geldings  is  more  than  one-seventh  higher,  and  the  lowest  is  considerably  above 
the  average  of  the  preceding,  while  the  highest  far  exceeds  the  highest  among 
the  entire  Horses.  It  is  curious  that  Gall  would  have  been  much  nearer  the 
truth,  if  he  had  said  that  the  dimensions  of  the  Cerebrum  are  usually  reduced 
by  castration;  for  it  appears  from  the  following  table  that  such  is  really  the 
case : — 

Average.  Greatest.  Least. 

Stallions 433  485  350 

Mares 402  432  336 

Geldings 419  566  346 

The  weight  of  the  largest  Cerebrum  of  the  Gelding  is  far  above  the  highest  of 
the  Stallions ;  but  it  seems  to  have  been  an  extraordinary  case,  as  in  no  other 
was  the  weight  above  490  gr.  If  this  one  be  excluded,  the  average  will  be 
reduced  still  further,  being  then  about  412 ;  this  may  be  seen,  by  looking  over 
the  whole  table,  to  give  a  very  fair  idea  of  the  usual  weight  in  "these  animals,, 
which  is  therefore  less,  by  about  one-twentieth,  than  the  average  in  the  Stallions. 
— The  increased  size  of  the  Cerebellum  in  Geldings  may  perhaps  be  accounted- 
for,  by  remembering  that  this  class  of  horses  is  solely  employed  for  its  muscular 


520  FUNCTIONS   OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

power,  and  that  the  constant  exercise  of  the  organ  is  not  unlikely  to  develop  its 
size;  whilst  Stallions,  being  kept  especially  for  the  purpose  of  propagation,  are 
much  less  applied  to  occupations  which  call  forth  their  motor  activity. 

559.  It  is  asserted,  however,  by  the  followers  of  Gall,  that  very  strong  evidence 
of  the  truth  of  his  docrine  is  afforded  by  Pathological  phenomena :  excitement 
of  the  genital  organs,  manifesting  itself  in  priapism,  turgescence  of  the  testes, 
and  seminal  emissions,  being  an  ordinary  concomitant  of  some  forms  of  apoplexy 
in  which  the  Cerebellum  is  affected ;  whilst  in  other  cases  of  disease  or  injury 
involving  extensive  destruction  of  the  substance  of  the  organ,  there  has  been  a 
complete  abatement  of  sexual  desire.  The  proportion  of  recorded  cases  of  disease 
of  the  Cerebellum,  however,  in  which  any  affection  of  the  genital  organs  has  been 
noticed,  is  extremely  small;  for  out  of  178  cases  which  have  been  collected  by 
Burdach,1  only  10,  or  scarcely  more  than  1  in  18,  presented  any  symptoms  that 
tended  to  indicate  a  functional  relation  between  the  Cerebellum  and  the  Genital 
organs.  The  same  physiologist  affirms  that  similar  affections  present  themselves, 
when  the  Cerebrum  is  the  seat  of  the  lesion;  and  there  seems  a  strong  proba- 
bility that  it  is  solely  to  the  connection  of  these  organs  with  the  Spinal  Cord, 
that  such  affections  of  the  genital  apparatus  are  due.  For  erection  of  the  penis 
has  been  noticed  in  a  far  larger  proportion  of  cases  in  which  the  Spinal  Cord 
itself  has  been  the  seat  of  the  lesion ;  thus  in  15  cases  in  which  the  cervical  por- 
tion of  the  Cord  was  affected,  erection  of  the  penis  was  observed  in  8 ;  and  in  13 
cases  of  lesion  of  the  dorso-lumbar  portion  of  the  cord,  erection  of  the  penis  took 
place  in  3.*  It  is  well  known  that  erection  of  the  penis  and  emissio  seminis  are 
not  unfrequent  phenomena  of  death  by  hanging;  and  this  fact  accords  fully  as 
well  with  the  idea  that  the  affection  of  the  sexual  organs  is  consequent  upon 
lesion  of  the  Cranio-Spinal  axis,  as  with  the  doctrine  that  it  is  due  to  disordered 
function  of  the  Cerebellum. — It  has  been  suggested  by  Serres,3  who  collected 
seven  cases  in  which  excitement  of  the  genital  organs  was  coincident  with  apo- 
plexy of  the  median  lobe  of  the  Cerebellum,  that  whilst  the  lateral  lobes  or  hemi- 
spheres may  be  connected  with  the  locomotive  function,  the  median  lobe  may  be 
the  organ  of  the  sexual  instinct.  Several  cases  have  been  recorded,  in  which 
some  such  relation  appeared  to  be  indicated;  and  the  Author  has  been  made 
acquainted  with  at  least  six,4  in  which  an  extraordinary  salacity  developed  itself 
at  an  advanced  period  of  life,  whilst,  concurrently  with  this,  or  following  upon  it, 
there  was  that  kind  of  unsteadiness  of  gait  which  may  be  held  to  indicate  chronic 
disease  of  the  Cerebellum.  In  one  of  these  cases,  of  which  the  history  and  post- 
mortem appearances  have  been  carefully  recorded  bj  Mr.  Dunn,6  there  was  strong 
evidence  that  the  excitement  of  the  sexual  propensity  was  coincident  with  the  irri- 
tative stage  of  incipient  disease  in  the  central  lobe  of  the  Cerebellum,  and  that  the 
abatement  of  the  propensity  was  in  like  manner  coincident  with  the  subsequent 
destruction  of  its  substance ;  whilst  the  advance  of  the  disease  into  the  lateral  lobes 
was  marked  by  impairment  of  the  power  of  co-ordination  of  movement.  But  with 
regard  to  all  such  cases,  and  others  that  may  be  ranked  in  the  same  category,6  the 

"VomBaue  und  Leben  des  Gehirns,"  (Leipzig,  1819-26),  band  iii. 

See  the  "  Traite"  des  Maladies  de  la  Moelle  Epiniere"  of  M.  Ollivier  (d'Angers),  3ieme 
ed  t.,  torn.  iii.  p.  316. 

"  Anatomic  Compared  du  Cerveau,"  torn.  ii.  p.  601,  717. 

Four  such  cases  have  come  under  the  notice  of  his  friend  Dr.  Simpson  of  York. 

"  Medico-Chirurgical  Transactions,"  vol.  xxxii. 

Thus,  a  case  has  been  communicated  to  the  Author  by  Mr.  Turley  of  Worcester,  in 
which  the  sexual  desire,  which  had  been  always  strong  through  life,  but  which  had  been 
controlled  within  the  limits  of  decency,  manifested  itself,  during  a  period  of  some  months 
preceding  death,  in  a  most  extraordinary  degree ;  on  post  mortem  examination,  a  tumour 
was  found  on  the  Pons  Varolii. — And  he  has  been  informed  of  another  case  by  Dr.  Evanson 
{formerly  of  Dublin),  in  which  a  young  officer  on  the  eve  of  marriage,  having  received  a 
blow  on  the  occiput  by  a  fall  from  his  horse,  became  impotent,  without  any  other  disorder 
of  his  bodily  or  mental  powers :  and  in  the  distress  consequent  upon  this  discovery,  com- 
ruittei  suicide  on  the  morning  fixed  for  his  wedding. 


THE    CEREBELLUM,    AND    ITS    FUNCTIONS.  521 

objection  of  Petrequin1  holds  good,  that  when  disease  or  injury  affects  the 
median  lobe  of  the  Cerebellum,  the  Medulla  Oblongata  is  almost  certain  to  be 
implicated  in  it ;  so  that,  as  the  evidence  already  referred-to  clearly  indicates  the 
existence  of  a  special  relation  between  the  genital  organs  and  the  upper  part 
of  the  Spinal  Axis,  no  positive  proof  is  afforded  by  them  that  any  portion  of  the 
Cerebellum  has  any  special  connection  with  the  generative  function. 

560.  The  Author  is  far  from  denying  in  toto,  that  any  peculiar  connection  exists 
"between  the  Cerebellum  and  the  Genital  system  ;  but  if  the  evidence  at  present 
adduced  in  support  of  the  Phrenological  position  be  held  sufficient  to  establish 
it,  in  defiance  of  so  many  opposing  considerations,  we  must  bid  adieu  to  all  safe 
reasoning  in  Physiology.     The  weight  of  testimony  appears  to  him  to  be  quite 
decided,  in  regard  to  the  connection  of  the  Cerebellum  with  the  regulation  of  the 
motor  function.;  and  as  an  additional  argument  in  favour  of  this  view,  it  may  be 
stated,  that  the  lobes  of  the  Human  Cerebellum  undergo  their  most  rapid  de- 
velopment during  the  first  few  years  of  life,  when  a  large  number  of  complex 
voluntary  movements  are  being  learned  by  experience,  and  are  being  associated 
by  means  of  the  muscular  sensations  accompanying  them;  whilst  in  those  ani- 
mals which  have,  immediately  after  birth,  the  power  of  regulating  their  voluntary 
movements  for  definite  objects,  with  the  greatest  precision,  the  Cerebellum  is 
more  fully  developed  at  the  time  of  birth.     In  both  instances  it  is  well  formed 
and  in  active  operation  (so  far  as  can  be  judged-of  by  the  amount  of  circulation 
through  it),  long  before  the  sexual  instinct  manifests  itself  in  any  perceptible 
degree. — But  neither  doctrine  need  be  maintained  altogether  to  the  exclusion  of 
the  other ;  and  there  are  many  among  the  Phrenologists  of  the  present  day,  who 
hold,  with  Serres,  that  whilst  the  hemispheres  of  the  Cerebellum  possess  the  en- 
dowments now  generally  assigned  to  them  by  Physiologists,  the  central  lobe  is 
connected  with  the  Genital  function.     It  has  been  shown  by  Dr.  N.  S.  Davis,* 
however,  that  there  is  no  perceptible  difference  in  the  dimensions  of  this  central 
lobe,  any  more  than  in  those  of  the  hemispheres,  between  Bulls  and  Oxen;  and 
no  proof  has  yet  been  offered,  save  that  afforded  by  the  pathological  evidence 
just  referred-to,  that  any  such  endowment  is  possessed  by  it.     That  in  some  way 
or  other,  however,  either  the  central  portion  of  the  Cerebellum,  or  some  part  of 
the  Medulla  Oblongata,  has  a  special  connection  with  the  Generative  function, 
appears  to  the  Author  to  be  indicated  with  tolerable  clearness  by  several  of  the 
Pathological  phenomena  already  cited.     The  circumstance,  too,  of  which  he  has 
frequently  been  assured,  that  great  application  to  gymnastic  exercises  diminishes 
for  a  time  the  sexual  vigour,  and  even  totally  suspends  desire,  seems  worthy  of 
consideration  in  reference  to  such  a  view ;  for  if  the  Cerebellum  be  really  con- 
nected with  both  kinds  of  function,  it  does  not  seem  unreasonable  that  the 
excessive  employment  of  it  upon  one  should  diminish  its  energy  in  regard  to  the 
other. — An  analysis  of  the  nature  of  the  Sexual  propensity,  however,  suggests 
the  conclusion  that  we  are  not  to  look  in  this  part  of  the  Encephalon  for  anything 
else  than  a  seat  of  the  sexual  sensation;  the  character  of  which  seems  to  be  suf- 
ficiently different  from  that  of  mere  tactile  sensation,  to  require  a  distinct  gan- 
glionic  centre.     Such  a  centre  would  be  likely  to  be  placed  in  the  line  of  the 
other  sensory  ganglia,  and  in  close  connection  with  them. 

561.  As  in  the  case  of  other  sensations,  the  Sexual,  when  moderately  excited, 
may  give  rise  to  ideas,  emotions,  and  desires,  of  which  the  Cerebrum  is  the  seat; 
and  these  may  react  on  the  muscular  system  through  the  Intelligence  and  Will 
But  when  inordinately  excited,  or  when  not  kept  in  restraint  by  the  Will,  tho 
sexual  sensations  will  at  once  call  into  play  respondent  movements,  which  are 
then  to  be  regarded  as  purely  automatic;  this  is  the  case  in  Nymphamania  and 
Satyriasis  in  the  Human  subject;  and  it  is  probably  also  the  ordinary  mode  of 

1  « Sur  quelques  points  de  la  Physiologie  du  Cervelet  et  de  la  Moelle   Epiniere,'  in 
"  Gaz.  M&Iicale,"  1836,  torn.  iv.  p.  546. 

'  "  Transactions  of  American  Medical  Association,"  vol.  iii.  p.  415 


522  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

operation  of  this  sense,  in  such  of  the  lower  animals  as  have  not  psychical  power 
enough  to  form  a  conception  of  an  absent  object  of  gratification,  and  cannot, 
therefore,  be  said  to  have  sexual  desires.  Thus,  like  other  sensations,  it  may  act 
either  intelligently  or  automatically;  giving  rise  to  ideas,  by  transmission  to 
the  Cerebrum,  which  ideas,  associated  with  pleasurable  feelings,  originate  desires 
that  stimulate  the  Reasoning  powers  to  devise  means  for  their  gratification,  and 
excite  the  Will  to  the  necessary  actions ;  or,  by  its  immediate  action  upon  the 
motor  apparatus,  producing  respondent  movements. — Of  this  double  modus  ope 
randi  we  seem  to  have  sufficient  evidence.  For  among  many  of  the  lower  tribes 
of  animals,  at  the  time  when  the  generative  organs  are  in  a  state  of  functional 
activity,  the  presence  of  an  individual  of  the  opposite  sex,  indicated  by  the  sight, 
smell,  hearing,  or  touch,  immediately  excites  the  whole  train  of  instinctive  actions 
concerned  in  the  reproductive  operation ;  whilst  we  have  no  evidence  in  them  of 
any  voluntary  exertion,  resulting  from  the  existence  of  a  desire  entertained  in 
the  absence  of  the  object,  and  intended  for  the  gratification  of  that  desire.  In 
Man,  on  the  other  hand,  the  principal  operation  of  the  sexual  sensations  is  in 
awakening  desires  and  affections,  which  serve  as  excitements  to  the  intelligence 
and  as  motives  to  the  Will ;  and  it  is  only,  under  ordinary  circumstances,  when 
the  two  sexes  have  been  thus  brought  into  close  relation,  that  the  direct  reaction 
of  the  sexual  sensation  manifests  itself  in  automatic  movements.  In  cases,  how- 
ever, in  which  this  sensation  is  excited  in  unusual  strength,  it  may  completely 
overmaster  all  motives  to  the  repression  of  the  propensity,  and  may  even  entirely 
remove  the  actions  from  volitional  control ;  and  a  state  of  a  very  similar  kind 
exists  in  many  Idiots,  in  whom  the  sexual  propensity  exerts  a  dominant  power, 
not  because  it  is  in  itself  peculiarly  strong,  but  because,  the  Intelligence  being 
undeveloped,  it  acts  without  restraint  or  direction  from  the  Will. 

5.    The  Cerebrum,  and  its  Functions. 

562.  We  come,  in  the  last  place,  to  consider  the  functions  of  that  portion  of 
the  Nervous  Centres,  which  is  evidently,  in  Man,  the  predominant  organ  of  his 
whole  system ;  being  not  merely  the  instrument  of  his  Reasoning  faculties,  but 
also  possessing  a  direct  or  indirect  control  over  nearly  all  the  actions  of  his  corpo- 
real frame,  save  those  purely  vegetative  processes  which  are  most  completely  iso- 
lated from  his  animal  powers.  We  should  be  in  great  danger,  however,  of  coming 
to  an  erroneous  conclusion  as  to  the  real  character  of  the  Cerebrum  and  of  its 
operations,  if  we  confined  ourselves  to  the  study  of  the  Human  organism ;  and 
the  history  of  Physiological  science  shows,  that  every  advance  of  knowledge 
respecting  its  functions  has  tended  to  limit  them,  whilst  at  the  same  time  render- 
ing them  more  precise.  Thus  the  Brain  (this  term,  in  the  older  Anatomy,  being 
chiefly  appropriated  to  the  Cerebrum)  was  once  accounted,  not  merely  the  centre 
of  all  motion  and  sensation,  but  also  the  source  of  all  vitality;  the  different  pro- 
cesses of  nutrition,  secretion,  &c.,  being  maintained,  it  was  supposed,  by  a  con- 
stant supply  of  <  animal  spirits/  propagated  from  the  brain,  along  the  nerves,  to 
each  individual  part.  The  more  modern  doctrine,  that  the  Sympathetic  System 
has  for  its  special  function  to  supply  the  nervous  influence  requisite  for  the 
maintenance  of  the  functions  of  Organic  life,  was  the  first  step  in  the  process  of 
limitation ;  still  the  Brain  was  regarded  as  the  centre  of  all  the  Animal  functions  ; 
and  no  other  part  was  admitted  to  possess  any  power  independently  of  it.  By 
experiments  and  pathological  observations,  however,  the  powers  of  the  Spinal 
Cord  as  an  independent  centre  of  action  were  next  established ;  and  it  was  thus 
•shown  that  there  is  a  large  class  of  motions  in  which  the  Brain  has  no  concern, 
and  that  the  removal  of  the  Cerebral  hemispheres  is  not  incompatible  (even  among 
the  higher  Vertebrata)  with  the  prolonged  maintenance  of  a  sort  of  inert  and 
scarcely  conscious  life.  Still,  it  has  been  usually  maintained,  and  with  great  show 
•>t  reason,  that  the  Cerebrum  is  the  instrument  of  all  psychical  operations,  and 


THE    CEREBRUM,    AND    ITS    FUNCTIONS.  523 

the  originator  of  all  the  movements  which  could  not  be  assigned  to  the  reflex 
action  of  the  Spinal  Cord.  An  attempt  has  been  made,  however,  in  the  preceding 
pages,  to  show  that  this  view  is  not  correct ;  and  that  there  is  a  class  of  actions, 
neither  excito-motor  nor  voluntary,  but  directly  consequent  upon  Sensations,  and 
constituting  (with  the  excito-motor)  the  truly  instinctive  actions,  which  may  be 
justly  assigned  to  certain  ganglionic  centres  not  less  independent  of  the  Cere- 
brum than  is  the  Spinal  Cord  itself.  It  has  been  further  pointed-out  that  the 
Cerebrum  must  be  considered  in  the  light  of  an  organ  mperadded  for  a  particular 
purpose,  or  set  of  purposes,  and  not  as  one  which  is  essential  to  life ;  that  it  has 
no  representative  among  the  Invertebrata  (except  in  a  few  of  the  highest  forms, 
which  evidently  present  a  transition  towards  the  Vertebrated  series ;  and  that,  at 
its  first  introduction  in  the  class  of  Fishes,  it  evidently  performs  a  subordinate 
part  in  the  general  actions  of  the  Nervous  System.  Hence,  whatever  be  the 
function,  or  set  of  functions,  we  assign  to  the  Cerebrum,  we  must  keep  in  view 
the  special  character  of  the  organ ;  and  must  never  lose  sight  of  the  fact,  that  its 
predominance  in  Man  does  not  deprive  other  parts  of  their  independent  powers, 
although  it  may  keep  the  exercise  of  those  powers  in  check,  and  may  consider- 
ably modify  their  manifestations. 

563.  Before  proceeding  to  inquire  into  the  Physiology  of  the  Cerebrum,  we 
may  advantageously  take  notice  of  some  of  the  leading  features  of  its  structure. — 
[n  the  first  place,  it  forms  an  exception  to  the  general  plan  on  which  the  ele- 
ments of  ganglionic  centres  are  arranged;  in  having  its  vesicular  substance  on 
the  exterior,  instead  of  in  the  central  part  of  the  mass.     The  purpose  of  this  is 
probably  to  allow  the  vesicular  matter  to  be  disposed  in  such  a  manner,  as  to  pre- 
sent a  very  large  surface,  instead  of  being  aggregated-together  in  a  more  compact 
mass ;  and  by  this  means  to  admit,  on  the  one  side,  a  more  ready  access  of  the 
blood-vessels  which  are  so  essential  to  the  functional  operations  of  this  tissue,  as 
well  as  a  more  ready  communication,  on  the  other,  with  the  vast  number  of 
fibres  by  which  its  influence  is  to  be  propagated.    There  is  no  reason  whatever  to 
believe  that  the  relative  functions  of  the  vesicular  and  fibrous  substances  are  in 
the  least  altered  by  this  change  in  their  relative  position ;  indeed,  the  results  of 
observation  upon  the  phenomena  of  disordered  Cerebral  action  are  such,  as  to 
afford  decided  confirmation  to  the  doctrine  now  generally  accepted,  that  the  action 
of  the  Vesicular  matter  constitutes  the  source  of  nervous  power,  whilst  the  Fi- 
brous structure  has  for  its  office  to  conduct  the  influence  thus  generated  to  the 
points  at  which  it  is  to  operate.     The  purpose  of  this  arrangement  is  further  evi- 
denced by  the  fact,  that,  in  all  the  higher  forms  of  Cerebral  structure,  we  find  a 
provision  for  a  still  greater  extension  of  the  surface  at  which  the  vesicular  matter 
and  the  blood-vessels  may  come  into  relation ;  this  being  effected  by  the  plication 
of  the  layer  of  vesicular  matter  into  'convolutions/  into  the  sulci  between  which, 
the  highly  vascular  membrane  known  as  the  '  pia  mater/   dips-down,  sending 
multitudes  of  small  vessels  from  its  inner  surface  into  the  substance  it  invests. 

564.  The  Cortical  substance  or  'grey  matter'  of  the  Hemispheres  essentially 
consists  of  that  vesicular  nerve-substance,  which,  in  the  Spinal  Cord,  as  in  gan- 
glionic masses  generally,  is  found  to  occupy  the  interior.     Its  usual  thickness  is 
about  one-fifth  of  an  inch ;  but  considerable  variations  present  themselves  in  this 
respect,  as  also  in  the  depth  of  the  convolutions.    Thus  the  plications  are  deepest, 
and  the  layer  of  'grey  matter '  the  thickest,  during  the  period  of  greatest  nerv- 
ous energy,  that  is,  in  middle  life ;  in  infancy  and  in  old  age,  the  convolutions 
are  simpler  and  have  fewer  undulations,  and  the  thickness  of  their  cortical  sub- 
stance is  much  inferior ;  and  the  same  is  true  of  the  adult  brain  of  some  of  the 
least  cultivated  races  of  mankind.     Three  layers  of  somewhat  different  hues  may 
be  distinguished  in  the  cortical  substance;  the  external,  white;  the  middle,  pure 
yrey ;  the  internal,  yellowish  red.     The  latter,  however,  may  generally  be  subdi- 
vided into  four ;  namely,  two  white  laminae,  alternating  with  two  yellowish-red 
iaminse.     Throughout  its  entire  thickness,  however,  nerve-cells  and  nerve-fibres 


524 


FUNCTIONS   OF   THE   CEREBRO-SPINAL  NERVOUS   SYSTEM. 


are  intermixed ;  and  these  are  imbedded  in  a  granular  matrix-substance.  Th<» 
nerve-cells  are  for  the  most  part  remarkable  for  the  number  of  pale,  slender,  branch- 
ing processes  which  they  give-off;  and  it  may  be  strongly  suspected,  though  it  has 
not  been  unequivocally  proved  by  observation,  that  these  are  continuous  with 
some  (at  least)  of  the  fibres  which  are  found  in  close  relation  to  them.  These 
cells'  are  most  abundant  in  the  middle  or  pure-grey  layer,  and  next  to  this  in  the 
internal  or  yellowish-red  layer ;  on  the  other  band,  in  the  external  white  layer, 
and  in  the  white  streaks  of  the  internal  layer,  the  fibres  spread-out  in  a  plane 
that  is  nearly  parallel  to  the  surface.  The  further  the  fibres  penetrate  from  the 
medullary  stratum  into  the  cortical  substance,  the  finer  do  they  become;  and  in 
the  external  white  lamina,  in  which  they  form  numerous  superimposed  layers, 
and  cross  each  other  in  various  directions,  they  are  reduced  to  their  very  smallest 
dimensions.  It  seems  certain  that  both  in  this  and  also  in  the  grey  layer,  some 
of  the  fibres  return  by  loops ;  although  it  has  not  been  yet  found  possible  to 
determine  to  what  order  of  fibres  these  belong.1 

565.  In  the  Medullary  or  fibrous  substance,  of  which  the  great  mass  of  the 
Cerebrum  is  composed,  three  principal  sets  of  fibres  may  be  distinguished.  These 
are, — -fir.st,  the  radiating  fibres,  which  connect  the  vesicular  matter  of  the  cortical 
substance  of  the  Hemispheres  with  the  Thalami  Optici,  and  which,  if  our  view 
of  the  function  of  the  latter  be  correct,  may  be  regarded  as  ascending ; — second, 
the  radiating  fibres  which  connect  the  vesicular  matter  of  the  cortical  substance 

FIG.  149. 


Diagram  of  the  mutual  relations  of  the  principal  Encephalic  centres,  as  shown  in  a  vertical 
section  : — A,  Cerebrum  ;  B,  Cerebellum  ;  c,  Sensori-motor  tract,  including  the  Olfactive  gan- 
glion olf,  the  Optic  opt,  and  the  Auditory  and,  with  the  Thalami  Optici  thai,  and  the  Corpora 
Striata  e«/  D,  Medulla  Oblongata;  E,  Spinal  Cord; — a,  olfactive  nerve;  b,  optic:  c,  audi- 
tory; d,  pneumogastric ;  e,  hypoglossal ;  /,  spinal:  fibres  of  the  medullary  substance  of  the 
Cerebrum  are  shown,  connecting  its  ganglionic  surface  with  the  Sensori-motor  tract. 

of  the  Hemispheres  with  the  Corpora  Striata,  and  which,  on  similar  grounds, 
may  be  regarded  as  descending;  and  third,  the  Commissural  fibres,  which  estab- 
lish the  connection  between  the  opposite  Hemispheres,  and  between  the  different 

1  See  Prof.  Kolliker's  "  Manual  of  Human  Histology,"  (Syden.  Soc.),  vol.  i.  pp.  439- 
443?  and  his  "  Mikroskopische  Anatomic,"  band  ii.  $  119, 


THE    CEREBRUM,    AND    ITS    FUNCTIONS.  525 

pares  of  the  vesicular  substance  of  the  same  side,  especially  between  that  disposed 
on  the  surface  of  each  hemisphere,  and  those  isolated  patches  which  are  found 
in  its  interior.  It  is  on  the  very  large  proportion  which  the  Comrnissural  fibres 
bear  to  the  rest,  that  the  bulk  of  the  Cerebrum  of  Man  and  of  the  higher  ani- 
mals seems  chiefly  to  depend;  and  it  is  easy  to  conceive,  that  this  condition  has 
an  important  relation  with  the  operations  of  the  Mind,  whatever  be  our  view  of 
tlie  relative  functions  of  different  parts  of  the  Cerebrum.  It  appears  from  the 
late  researches  of  M.  Baillarger,  that  the  surface  and  the  Itulk  of  the  cerebral 
hemispheres  are  so  far  from  bearing  any  constant  proportion  to  each  other,  in 
different  animals,  that,  notwithstanding  the  depth  of  the  convolutions  in  the 
Human  Cerebrum,  its  bulk  is  2^  times  *as  great  in  proportion  to  its  surface,  as  it 
is  in  the  Rabbit,  the  surface  of  whose  Cerebrum  is  smooth.  The  entire  surface 
of  the  Human  Cerebrum  is  estimated  by  him  at  about  670  square  inches.1 

566.  With  regard  to  the  Radiating  fibres,  which  connect  the  Corpora  Striata 
and  Thalami  Optici  with  the  vesicular  surface  of  the  Cerebral  hemispheres,  not 
only  has  no  positive  proof  yet  been  obtained  of  their  direct  continuity  with  those 
which  enter  into  the  composition  of  the  nerves  proceeding  from  the  Spinal  Cord 
and  Medulla  Oblongata ;  but  the  results  of  the  most  recent  and  careful  examination 
are  in  opposition  to  such  an  idea  (§  519).    And  we  have  seen  that  there  are  certain 
phenomena,  which  are  best  explained  by  considering  these  radiating  fibres  as  of 
a  commissural  nature  only;  and  as  serving  to  connect  the  vesicular  matter  of  the 
Cerebrum  with  that  of  the  higher  portions  of  the  Cranio- Spinal  Axis,  through 
which  alone  they  are  brought  into  relation  with  the  central  terminations  of  the 
afferent  nerves,  and  with  origins  of  the  motor  (§  544). — Thus  the  Anatomical 
relation  which  the  grey  matter  of  the  Cerebral  convolutions  bears  to  the  central 
Sensorium,  precisely  corresponds  with  that  which  is  borne  to  it  by  the  Retina, 
which  essentially  consists,  like  it,  of  an  expansion  of  vesicular  substance  (§754); 
whilst  the  radiating  fibres  of  the  medullary  substance  answer  precisely  to  the 
Optic  Nerve.     And  it  is  a  most  important  confirmation  of  this  view,  that  such  a 
relation  is  also  shown  to  exist  by  the  history  of  Development.     For  the  cortical 
substance  of  the  Cerebrum  and  the  Retina  alike  originate  as  offsets  from  the 
Sensory  Ganglia;  the  former  detaching  itself  from  the  Corpus  Striattim  on  either 
side,  the  latter  from  the  Thalamus  Opticus ;  and  each  being  gradually  removed 
to  a  greater  and  greater  distance  from  its  original  centre,  by  the  elongation  of  the 
intervening  commissural  tract.     It  seems  to  have  been  a  kind  of  recognition  of 
this  analogy,  which  long  since  led  the  sagacious  Reil  to  designate  the  Cerebral 
lobes  as  a  congeries  of  *  nerves  of  the  internal  senses.'2 

567.  The  Commissural  fibres  constitute  two  principal  groups,  the  transverse, 
and  the  longitudinal ;  the  former  connecting  the  two  Hemispheres  with  each 
other;  the  latter  uniting  the  different  parts  of  the  same  Hemisphere. — Of  the 
transverse  commissures,  the  Corpus  Callosum  is  the  most  important  (Fig.  150). 
This  consists  of  a  mass  of  fibres  very  closely  interlaced  together ;  which  may  be 
traced  into  the  substance  of  the  hemispheres  on  each  side,  particularly  at  their 
lower  part,  where  their  connections  are  the  closest  with  the  Thalami  Optici  and 
Corpora  Striata.     It  is  difficult,  if  not  impossible,  to  trace  its  fibres  any  further; 

1  The  inference  drawn  by  M.  Baillarger  from  the  facts  he  has  collected, — namely,  that 
the  proportional  surface  of  vesicular  matter  in  different  animals,  whether  considered  abso- 
lutely, or  relatively  to  the  volume  of  the  Cerebrum,  has  no  correspondence  with  their 
intellectual  capability, — is  far  too  sweeping  an  assumption ;  since,  as  above  shown,  the 
increase  in  the  commissural  fibres,  causing  an  augmentation  of  the  bulk  of  the  Cerebrum, 
may  be  alike  the  cause  of  increased  intelligence  and  of  a  diminished  proportional  amount 
of  vesicular  matter,  though  the  latter  still  remains  as  the  original  source  of  power. 

a  He  says  "  The  nerves  of  the  external  senses  and  voluntary  muscles  escape  from  the 
cranium  forwards  and  backwards,  and  ramify  over  the  whole  of  the  body  so  as  to  connect 
it  with  the  organ  of  the  soul ;  the  nerves  of  the  internal  senses,  [moral  and  intellectual 
faculties],  on  the  other  hand,  have  no  object  beyond  the  cranium,  and  are  therefore  found 
rolled-up  on  themselves  and  forming  the  masses  of  the  brain."  (Archiv.  fur  Physiol., 
1802  baud  vi.,  a.  406.) 


526 


FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS    SYSTEM. 
[Fio.  150. 


This  figure  is  intended  to  show  the  course  and  connection  of  the  fibres  of  the  great  trans- 
verse commissure  of  the  hemispheres  or  corpus  callosum.  The  dissection  has  only  been  car- 
ried into  the  right  hemisphere.  It  will  be  seen  that  these  fibres  ascend  to  the  convolutions 
above  the  mesial  line,  p  p  p.  Fibres  of  the  corpus  callosum  radiating  into  the  hemispherical 
ganglion.  B.  Left  hemispherical  ganglion  undissected.  E.  Cerebellum.  Near  the  centre  of 
the  drawing,  and  a  little  to  the  right  of  the  mesial  line,  is  the  representation  of  a  broken  fas- 
ciculus of  fibres — the  part  torn  off  was  traced  most  carefully  into  the  convoluted  surface  of  the 
brain. — ED.] 

but  there  can  be  little  doubt  that  they  radiate,  with  the  fibres  proceeding  from 
the  bodies  just  named,  to  different  parts  of  the  cortical  substance  of  the  Hemi- 
spheres. This  commissure  is  altogether  wanting  in  Fish,  Reptiles,  and  Birds; 
and  it  is  partially  or  completely  wanting  in  those  Mammals  whose  Cerebrum  is 
formed  upon  the  least  complex  plan, — the  Rodents  and  Marsupials.  Although 
the  Anterior  commissure  particularly  unites  the  Corpora  Striata  of  the  two  sides, 
many  of  its  fibres  pass  through  those  organs,  and  radiate  towards  the  convolutions 
of  the  Hemispheres,  especially  those  of  the  middle  lobe;  this  commissure  is  par- 
ticularly large  in  those  Marsupials,  in  which  the  Corpus  Callosum  is  deficient. — 
Of  the  longitudinal  commissures,  some  lie  above,  and  others  below,  the  Corpus 
Callosum.  Upon  the  transverse  fibres  of  that  body,  there  is  a  longitudinal  tract 
on  each  side  of  the  median  line,  which  serves  to  connect  the  convolutions  of  the 
anterior  and  posterior  Cerebral  lobes.  Above  this,  again,  is  the  Superior  longi- 
tudinal commissure  (Fig.  151),  which  is  formed  by  the  fibrous  matter  of  the 
greater  convolutions  nearest  the  median  plane  on  the  upper  surface  of  the  Cere- 
brum, and  which  connects  the  convolutions  of  the  anterior  and  middle  lobes  with 
those  of  the  posterior.  Beneath  the  Corpus  Callosum,  we  find  the  most  extensive 
of  all  the  longitudinal  commissures,  the  Fornix  (Fig.  153).  This  is  connected 
in  front  with  the  Thalami  Optici,  the  Corpora  Mammillaria,  the  Tuber  Cinereum, 
<fec. ;  and  behind,  it  spreads  its  fibres  over  the  Hippocampi  (major  and  minor), 
which  arc  nothing  else  than  peculiar  convolutions  that  project  into  the  posterior 
and  descending  cornua  of  the  lateral  ventricles.  The  fourth  longitudinaJ  commis- 
sure is  the  Tsenia  semicircularis,  which  forms  part  of  the  same  system  of  fibre* 


THE     CEREBRUM,     AND     ITS     FUNCTIONS. 


527 


[Fio.  151. 


This  figure  represents  longitudinal  fibres  placed  above  the  great  transverse  commissure  cor- 
responding with  those  which  we  have  just  observed  below  it — the  superior  longitudinal  commis- 
sure. The  relations  being  more  simple  than  those  of  the  inferior  commissure,  are  simply  desig- 
nated by  the  letters  s  L,  s  L.  They  are  traced,  ascending  forwards,  from  the  locus  quadratus, 
which  is  anterior  to  the  fissura  Sylvii,  and  then,  curving  backwards  and  winding  round  tho 
front  of  the  great  transverse  commissure  (p),  receiving  fibres  from  all  the  convolutions  at  the 
upper  and  sides  of  the  hemispheres,  winding  round  the  posterior  extremity  of  the  same  com- 
missure, and  terminating  after  crossing  the  fissura  Sylvii,  where  it  commenced  in  the  locus 
quadratus  at  the  base  of  the  brain.  H.  Spinal  cord.  j.  Pituitary  gland,  just  above  which  is 
the  divided  optic  nerve.  N.  Letter  placed  on  the  crus  cerebri,  and  behind  that  root  of  the  for- 
nix  which  springs  from  the  interior  of  the  thalamus.  p.  Great  transverse  commissure,  s.  Oli- 
vary ganglion,  a.  Olfactory  ganglion,  c,  D.  Optic  ganglia,  c,  a.  Corpus  mammillare,  formed 
by  the  twist  of  the  fornix.  c,  m.  Cotnmissura  mollis  in  the  third  ventricle,  k.  Optic  thalamns. 
o.  Peduncle  of  the  pineal  gland:  if  this  line  is  traced  backwards,  it  will  be  found  connected 
with  a  dark  rounded  body,  the  pineal  gland,  which  is  lying  on  the  anterior  optic  tubercle — 
nates ;  if  this  line  is  traced  forwards,  it  will  be  seen  joining  the  anterior  pillar  of  the  fornix, 
which  has  been  turned  down  to  show  this  connection.  The  divided  end  of  the  fornix  is  turned 
towards  us.  p,  c.  Posterior  commissure,  s.  Tasnia  semicircularis  joining  the  fornix  at  tho 
same  point.  This  letter  is  placed  in  the  anterior  cornu  of  the  lateral  ventricle  on  the  corpus 
striatum.  This  junction  is  very  distinct  in  both  the  recent  and  hardened  brain,  though  the 
connecting  fibres  are  too  delicate  to  be  done  justice  to  in  a  woodcut.  4.  Fourth  ventricle,  p.  Iter 
a  tertio  ad  quartuin  ventriculum.  u.  Posterior  commissure. — ED.] 

with  the  fornix ;  connecting  the  corpus  mammillare  and  thalamus  opticus  of  each 
side  with  the  middle  lobe  of  the  cerebral  hemisphere.  If,  as  Dr.  Todd  has 
remarked,1  we  could  take  away  the  corpus  callosum,  the  grey  matter  of  the  inter- 
nal convolution,  and  the  ventricular  prominence  of  the  optic  thalami,  then  all 
these  commissures  would  fall-together,  and  would  become  united  in  the  same 
series  of  longitudinal  fibres. — Experiment  does  not  throw  any  light  upon  the 
particular  functions  of  the  Corpus  Callosum  and  other  Commissures ;  since  they 
can  scarcely  be  divided  without  severe  general  injury.  It  would  appear,  how- 
ever, that  the  partial  or  entire  absence  of  these  parts,  reducing  the  Cerebrum  (in 

*  "Anatomy  of  the  Brain,  Spinal  Cord,"  &c.,  p.  234. 


5*28  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

[FrrT.  152. 


This  figure  has  been  introduced  with  the  view  of  assisting  the  student  in  his  study  of  the  rela- 
tions of  the  inferior  longitudinal  commissure  or  for  nix,  which  may  be  described  as  commencing 
in  the  centre  of  the  thalamus  nervi  optici  (L),  proceeding  from  thence  to  the  base  of  the  brain, 
where  it  suddenly  bends  upwards  and  forwards,  forming  by  this  turn  the  knuckle  (B),  which  is 
called  corpus  albicans  or  mammillare.  This  body  receives  a  few  fibres  (A),  from  the  locus  niger 
(6)  in  the  crus  cerebri  (5),  running  forward  from  thence  towards  the  anterior  commissure,  re- 
ceiving fibres  from  the  convolutions  at  the  base  of  the  brain,  crossing  and  as  it  were  kneel- 
ing upon  the  anterior  commissure  (s),  and,  ascending  towards  the  great  transverse  commissure, 
forms  the  anterior  pillar  of  the  fornix  (c),  receiving  fibres  in  its  course  from  the  under  and  front 
part  of  the  anterior  lobes,  and  thus  forming  the  septum  lucidum  (D)  ;  running  back  from  thence, 
passing  in  its  course  backwards  over  the  thalamus  nervi  optici  (L),  it  spreads  laterally,  consti- 
tuting that  portion  which  is  called  the  body  of  the  fornix  (E)  :  descending  again  at  the  bacu 
part  of  the  brain,  it  forms  the  descending  or  posterior  pillar  of  the  fornix  tcenia  hippocampi 
(F),  some  of  its  fibres  running  back  to  be  connected  with  the  posterior  lobes  (i) ;  others  cross- 
ing the  projection  called  hippocampus  major  (G),  to  be  connected  with  the  middle  lobe,  and 
others  again  passing  over  the  pes  hippocampi  (H)  to  be  connected  with  the  anterior  portion  of 
the  middle  lobe.  Thus  does  this  commissure  connect  different  portions  of  the  convoluted  sur- 
face of  the  brain  together,  which  are  inferior  to  the  great  transverse  commissure,  and  on  the 
same  side  of  the  mesial  line.  A.  Fibres  of  the  inferior  longitudinal  commissure,  or  fornix,  from 
the  locus  niger.  B.  Corpus  mammillare.  c.  Anterior  pillars  of  inferior  longitudinal  commis- 
sure, or  fornix.  D.  Septum  lucidum.  E.  Body  of  the  fornix,  or  centre  of  the  commissure. 
F.  Tsenia  hippocampi,  or  descending  fibres  of  the  inferior  longitudinal  commissure.  G.  Fibres 
covering  the  hippocampus  major.  H.  Fibres  covering  the  pes  hippocampi,  i.  Fibres  covering 
the  hippocampus  minor.  K.  Great  transverse  commissure  divided  in  the  mesial  line.  L.  Pos- 
terior cerebral  ganglion,  or  tbalamus.  L  Anterior  commissure.  5.  Section  of  the  crus  cere- 
bri. 6.  Locus  niger.  7.  Anterior  cerebral  ganglion,  or  corpus  striatuin  partially  scraped 
away. — ED.] 

this  respect  at  least)  to  the  level  of  that  of  the  Marsupial  Quadruped  or  of  the 
Bird,  is  by  no  means  an  unfrequent  cause  of  deficient  intellectual  power.1 

1  The  following  case  of  deficient  commissures,  recorded  by  Mr.  Paget  ("  Medico-Chirurg. 
Transactions,"  vol.  xxiv.),  is  of  much  interest.  The  middle  portion  of  the  Fornix,  and 
the  whole  of  the  Septum  Lucidum,  were  absent;  and  in  place  of  the  Corpus  Callosum, 
there  was  only  a  thin  fasciculated  layer  of  fibrous  matter,  1-4  inch  in  length,  of  which, 
however,  the  fibres  extended  to  all  the  parts  of  the  brain  into  which  the  fibres  of  the 
healthy  corpus  callosum  can  be  traced.  The  Middle  commissut-e  was  very  large ;  and  the 
lateral  part  of  the  Fornix,  with  the  rest  of  the  Brain,  was  quite  healthy.  The  patient  was 
a  servant-girl,  who  died  of  pericarditis.  She  had  displayed  nothing  very  remarkable  in 
her  mental  condition,  during  her  life,  beyond  a  peculiar  want  of  forethought  and  power  of 
judging  of  the  probable  event  of  things.  Her  memory  was  good  ;  and  she  possessed  as  much 
ordinary  knowledge  as  is  commonly  acquired  by  persons  in  her  rank  of  life.  She  was  of 
good  moral  character,  trustworthy,  and  fully  competent  to  all  the  duties  of  her  station, 
though  somewhat  heedless;  her  temper  was  good,  and  disposition  cheerful. — The  mental 
deficiencies  in  most  of  the  few  other  cases  of  which  the  details  have  been  recorded,  seem  to 


THE     CEREBRUM,     AND    ITS    FUNCTIONS.  529 

568.  The  weight  of  the  entire  Encephalon  in  the  adult  Male  usually  ranges 
between  40  and  60  oz.,  the  average  being  about  50  oz. ;  and  in  the  Female  from 
86   to  50  oz.,  the  average  being  about  45  oz.     The  maximum  of  the  healthy 
brain  seems  to  be  about  64  oz.,  and  the  minimum  about  31  oz.     But  in  cases  of 
Idiocy,  the  amount  is  sometimes  much  below  this ;  as  low  a  weight  as  20  ounces 
having  been  recorded. — It  appears,  from  the  recent  investigations  of  M.  Bour- 
gery,  that  the  relative  sizes  of  the  different  component  elements  of  the  Human 
Eucephalon  are  somewhat  as  follows.     Dividing  the  whole  into  204  parts,  the 
weight  of  the  Cerebrum  will  be  represented  by  about  170  of  those  parts,  that  of 
the  Cerebrum  by  21,  and  that  of  the  Medulla  Oblongata  with  the  Optic  Thalami 
and  Corpora  Striata  at  13.     The  weight  of  the  Spinal  Cord  would  be,  on  the 
same  scale  7  parts.     Hence  the  Cerebral  Hemispheres  of  Man  include  an  amount 
of  nervous  matter,  which  is/owr  times  that  of  all  the  rest  of  the  Cranio-Spinal  mass, 
more  than  eiyht  times  that  of  the  Cerebellum,  thirteen  times  that  of  the  Medulla 
Oblongata,  &c.,  and   twenty-four  times  that  of  the  Spinal  Cord. — The  average 
weight  of  the  whole  Encephalon,  in  proportion  to  that  of  the  body,  in  Man, 
taking  the  average  of  a  great  number  of  observations,  is  about  1  to  36.     This  is 
a  much  larger  proportion  than  that  which  obtains  in  most  other  animals;  thus 
the  average  of  Mammalia  is  stated  by  M.  Leuret  to  be  1  to  186,  that  of  Birds  1  to 
212,  that  of  Reptiles  1  to  1321,  and  that  of  Fishes  1  to  5668.     It  is  interesting 
to  remark,  in  reference  to  these  estimates,  that  the  Encephalic  prolongation  of 
the  Medulla  Oblongata  in  Man  (being  about  one-sixteenth  of  the  weight  of  the 
whole  Encephalon)  is  alone  more  than  twice  as  heavy  in  proportion  to  his  body, 
as  the  entire  Encephalon  of  Reptiles,  and  ten  times  as  heavy  as  that  of  Fish. — 
But  there  are  some  animals  in  which  the  weight  of  the  Encephalon  bears  a  higher 
proportion  to  that  of  the  body  than  it  does  in  Man  ;  thus  in  the  Blue-headed 
Tit,  the  proportion  is  as  1  to  12,  in  the  Goldfinch  as  1  to  24,  and  in  the  Field- 
Mouse  as  1  to  31.     It  does  not  hence  follow,  however,  that  the  Cerebrum  is 
larger  in  proportion ;  in  fact,  it  is  probably  not  nearly  so  large ;  for  in  Birds  and 
Rodent  Mammals,  the  Sensory  Ganglia  form  a  very  considerable  proportion  of 
the  Encephalon.     The  importance  of  distinguishing  between   the  several  parts 
of  this  mass,  which  are  marked-out  as  distinct,  alike  by  their  structure  and  con- 
nections, and  by  the  history  of  their  development,  has  not  been  by  any  means 
sufficiently  attended  to. 

569.  The  Encephalon  altogether  receives  a  supply  of  Blood,  the  amount  of 
which  is  very  remarkable,  when  its  comparative  bulk  is  considered;  the  propor- 
tion which  goes  to  it  being,  according  to  the  estimate  of  Haller,  as  much  as  one- 
fifth  of  the  whole  mass.     The  manner  in  which  this  blood  is  conveyed  to  the 
brain,  and  the  conditions  of  its  distribution,  offer  some  peculiarities  worthy  of 
notice.     The  two  Vertebral  and  two  Carotid  arteries,  by  which  the  blood  enters 
the  cavity  of  the  cranium,  have  a  more  free  communication  by  anastomosis,  than 
any  similar  set  of  arteries  elsewhere;  and  this  is  obviously  destined  to  prevent 
an  obstruction  in  one  trunk  from  interrupting  the  supply  of  blood  to  the  parts 
through  which  its  branches  are  chiefly  distributed, — the  cessation  of  the  circula- 
have  been  of  the  same  order ;  and  this  is  exactly  what  might  have  been  anticipated  ;  since 
the  deprivation  of  these  parts  takes  away  that,  which  is  most  characteristic  of  the  Cere- 
brum of  Man  and  of  the  higher  Mammalia;  their  intellectual  operations  being  peculiarly 
distinguished  by  that  application  of  past  experience  to  the  prediction  of  the  future,  which  con- 
stitutes one  of  the  highest  efforts  of  intelligence. — Another  case  has  been  since  put  on 
record  by  Mr.  Mitchell  Henry  (Op.  cit.,  vol.  xxxi.),  in  which  the  anterior  portion  of  the 
Corpus  Callosum  was  deficient,  together  with  the  middle  and  anterior  portion  of  the  For- 
nix,  and  the  whole  of  the  Septum  Lucidum.     There  was  in  this  case  also,  a  marked  intel- 
lectual deficiency,  but  apparently  of  a  different  character  from  that  which  showed  itself  in 
the  preceding  case  ;  for  instead  of  vivacity  and  habitual  rapidity  of  action,  there  was  here 
a  disproportionate  degree  of  slowness  in  action,  amounting  almost  to  stupidity.     The  dif- 
ference in  the  two  ca«es,  however,  is  perhaps  to  be  set-down  rather  to  the  account  of  gene- 
ral temperament;  since  in  both  of  them  there  seems  to  have  been  a  deficiency  in  tho 
power  of  carrying-on  a  continuous  train  of  thought. 

34 


530  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

tion  through  the  nervous  matter  being  immediately  productive  of  suspension  of  ita 
functional  activity  (PniNC.  OF  GEN.  PHYS.,  Am.  Ed.). — Not  only  must  there  be 
a  sufficient  supply  of  blood,  but  it  must  make  a  regulated  pressure  on  the  walls  of 
the  vessels.     Now  the  Encephalon  is  differently  circumstanced  from  other  vascular 
organs,  in  being  enclosed  within  an  unyielding  bony  case  (§  281) ;  and  we  find 
a  special  provision  for  equalizing  the  bulk  of  the  contents  of  this  cavity,  and  for 
counterbalacing  the  results  of  differences  in  the  functional  activity  of  the  brain 
and  in  its  supply  of  blood,  in  the  existence  of  a  fluid  which  is  found  beneath  the 
arachnoid,  both  on  the  surface  of  the  brain  and  spinal  cord,  and  in  the  ventricles 
of  the  former.     The  amount  of  this  l  cerebro-spinal  fluid '  seems  to  average  about 
two  ounces;  but  in  cases  of  atrophy  of  the  brain,  as  much  as  twelve  ounces  of 
fluid  may  sometimes  be  obtained  from  the  cranio-spinal  cavity;  whilst  in  all  in- 
stances in  which  the  bulk  of  the  brain  has  undergone  an  increase,  whether  from 
the  production  of  additional  nervous  tissue,  or  from  undue  turgescence  of  the 
vessels,  there  is  either  a  diminution  or  a  total  absence  of  this  fluid.     It  appears 
from  the  experiments  of  Magendie  (to  whom  our  knowledge  of  its  importance  is 
chiefly  due),  that  its  withdrawal  in  living  animals  causes  great  disturbance  of  the 
cerebral  functions,  probably  by  allowing  undue  distension  of  the  blood-vessels ;  it 
is,   however,   capable  of  being  very  rapidly  regenerated ;  and  its  reproduction 
restores  the  nervous  centres  to  their  natural  state. — As  the  '  cerebro-spinal  fluid' 
can  readily  find  its  way  from  the  sub-arachnoid  spaces  of  the  cranial  cavity  into 
those  of  the  spinal,  and  as  it  is  no  less  readily  absorbed  than  reproduced,  it  evi- 
dently serves  as  an  equalizer  of  the  amount  of  pressure  within  the  cranial  cavity; 
admitting  the  distension  or  contraction  of  the  vessels  to  take  place,  within  certain 
limits,  without  any  considerable  change  in  the  degree  of  compression  to  which 
the  nervous  matter  is  subjected.     That  this  uniformity  is  of  the  greatest  impor- 
tance to  the  functional  exercise  of  the  brain,  is  evident  from  a  few  well-known 
facts.     If  an  aperture  be  made  in  the  skull,  and  the  protruding  portion  of  the 
brain  be  subjected  to  pressure,  the  immediate  suspension  of  the  activity  of  the 
whole  organ  is  the  result;  in  this  manner,  a  state  resembling  profound  sleep  can 
be  induced  in  a  moment,  the  normal  activity  being  renewed  as  momentarily,  so 
soon  as  the  pressure  is  withdrawn.     This  phenomenon  has  often  been  observed 
in  the  Human  subject,  in  cases  in  which  a  portion  of  the  cranial  envelope  has 
been  lost  by  disease  or  injury.     The  various  symptoms  of  Cerebral  disturbance 
which  are  due  to  a  state  of  general  Plethora,  are  evidently  owing  to  an  excess  of 
pressure  within  the  vessels ;  but  an  undue  diminution  of  pressure  is  no  less  inju- 
rious, as  appears  from  the  disturbance  in  the  Cerebral  functions  which  results 
from  the  very  opposite  cause,  namely  a  depression  of  the  power  of  the  heart,  or  a 
deficiency  of  blood  in  the  vessels. — It  is  of  peculiar  importance  to  bear  in  mind 
the  disturbance  of  the  Cerebral  functions  occasioned  by  variations  of  internal 
pressure,  when  we  are  endeavouring  to  draw  inferences  from  the  phenomena  pre- 
sented by  disease. 

570.  We  shall  now  proceed  with  our  Physiological  inquiry  into  the  functions 
of  the  Cerebrum;  and  shall  appeal,  as  before,  to  Human  and  Comparative  Ana- 
tomy, to  Experiment,  and  to  Pathology,  for  our  chief  data. — The  anatomical  rela- 
tions of  the  Cerebrum  to  the  other  Encephalic  centres,  clearly  demonstrate  that 
it  is  not  one  of  the  essential  or  fundamental  portions  of  the  Nervous  system;  but 
a  superadded  organ,  receiving  all  its  impulses  to  action  from  the  parts  below,  and 
operating  upon  the  body  at  large  through  them.  And  its  great  bulk,  joined  to 
its  position  at  the  summit  of  the  whole  apparatus, — the  vesicular  substance  of  its 
convolutions  affording  a  termination  to  the  fibres  in  connection  with  it,  and  not 
being  for  the  most  part  only  traversed  by  them,  as  is  the  case  with  that  of  all  the 
Lower  centres, — clearly  mark  it  out  as  the  highest  in  its  functional  relations,  and 
as  ministering,  so  far  as  any  material  instrument  may  do,  to  the  exercise  of  those 
psychical  powers,  which,  in  Man,  exhibit  so  remarkable  a  predominance  over  the 
mere  animal  instincts.  This  conclusion  is  fully  borne-out,  when  we  extend  our 


AND    ITS    FUNCTIONS.  531 

inquiries  from  Human  to  Comparative  Anatomy;  for  with  some  apparent  excep- 
tions, which  there  would  probably  be  no  great  difficulty  in  explaining  if  we  were 
in  possession  of  all  the  requisite  data,  there  is  a  very  close  correspondence  be- 
tween the  relative  development  of  the  Cerebrum:  in  the  several  tribes  of  Verte- 
brata,1  and  the  degree  of  Intelligence  they  respectively  possess, — using  the  latter 
term  as  a  comprehensive  expression  of  that  series  of  mental  actions,  which  con- 
sists in  the  intentional  adaptation  of  means  to  ends,  based  oo  definite  ideas  as  to 
the  nature  of  both.  It  is  not  always  easy  to  say,  in  the  case  of  the  lower  ani- 
mals, what  parts  of  their  actions  are  to  be  attributed  to  automatic  impulses  (i.e. 
to  be  considered  as  Instinctive),  and  what  should  be  regarded  as  the  results  of 
Intelligence.  The  character  of  Intelligent  actions,  however,  as  compared  with 
Instinctive  (§  459),  is  usually  shown  (1)  in  the  variety  of  means  which  are 
adopted  to  compass  the  same  ends,  and  this  not  merely  by  different  individuals 
and  by  successive  generations,  but  by  the  same  individual  at  different  times;  (2) 
by  the  improvement  in  the  mode  of  accomplishing  the  object,  which  results  from 
the  intelligent  use  of  experience,  and  from  the  greater  command  of  means  which 
is  progressively  attained;  and  (3)  by  the  conformity  of  the  means  to  altered  cir- 
cumstances, so  that  the  character  of  adaptiveness  is  still  maintained,  however 
widely  the  new  conditions  may  depart  from  those  which  must  be  considered  as 
natural  to  the  species. 

571.  The  difference   between    actions  which   proceed   from   the  Intellectual 
faculties  prompted  by  the  instinctive  propensities,  and  those  of  a  purely  Instinc- 
tive character,  is  well  seen  in  comparing  Birds  with  Insects.     The  Instinctive 
tendencies  of  the  two  classes  are  of  nearly  the  same  kind;  and  the  usual  arts 
which  both  exhibit  in  the  construction  of  their  habitations,  in  procuring  their 
food,  ard  in  escaping  from  danger,  must  be  regarded  as  intuitive,  on  account  of 
the  uniformity  with  which  they  are  practised  by  different  individuals  of  the  same 
species,  and  the  perfection  with  which  they  are  exercised  on  the  very  first  occasion. 
But  in  the  adaptation  of  their  operations  to  peculiar  circumstances,  Birds  display  a 
variety  and   fertility  of  resource,  far   surpassing   that   tfhich  is  manifested   by 
Insects ;  and  it  can  scarcely  be  doubted  by  those  who  attentively  observe  their 
habits,  that  in  such  adaptations  they  are  often  guided  by  real  Intelligence.     This 
must  be  the  case,  for  example,  when  they  make  trial  of  several  means,  and  select 
that  one  which  best  answers  the  purpose ;  or  when  they  make  an  obvious  improve- 
ment from  year  to  year  in  the  comforts  of  their  dwelling;  or  when  they  are 
influenced  in  the  choice  of  a  situation,  by  peculiar  circumstances,  which  in  a 
state  of  nature  can  scarcely  be  supposed  to  affect  them.     The  complete  domesti- 
cability  of  many  Birds  is  in  itself  a  proof  of  their  possessing  a  certain  degree  of 
intelligence ;  but  this  alone  does  not  indicate  the  possession  of  more  than  a  very 
low  amount  of  it;    since  many  of  the  most  domesticable  animals   are  of  the 
humblest  intellectual  capacity,  and  seem  to  become  attached  to  Man,  principally 
as  the  source  on  which  they  depend  for  the  supply  of  their  animal  wants.     But 
there  are  certain  tribes  of  Birds,  especially  the  Parrots  and  their  allies,  which 
possess  an  extraordinary  degree  of  educdbility,  and  which  manifest  a  power  of 
performing  simple  acts  of  reasoning,  that  are  quite  comparable  with  those  of  a 
child  when  first  learning  to  talk. 

572.  This  development  of  the  Intelligence  under  the  influence  of  Man,  and 
iu  accordance  with  his  habits,  rather  than  with  the  original  habits  of  their  species, 
is  yet  more  remarkable  in  the  case  of  those  Mammals  whose  instincts  lead  them 
to  attach  themselves  peculiarly  to  him^  and  whose  powers  of  reasoning  are  called- 
forth  in  adapting  themselves  to  the  new  circumstances  in  which  they  are  thus 
placed.     The  actions  of  a  Dog,  a  Horse,  or  an  Elephant  are  evidently  the  result, 
in  many  instances,  of  a  complex  train  of  reasoning,  differing  in  no  essential  re- 
spect from  that  which  Man  would  perform  in  similar  circumstances;  so  that  th« 
epithet  l  half-reasoning/  commonly  applied  to  these  animals,  does  not  express  the 

1  See  "Princ.  of  Comp.  Phys.,"  Am.  Ed.,  \\  662,  et  seq. 


532  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

whole  truth ;  for  their  mental  processes  are  of  the  same  kind  with  those  of 
Man,  and  differ  more  in  the  degree  of  comprehensiveness  of  their  data  and  con- 
clusiveness  of  their  inferences,  than  they  do  in  their  essential  character.  We 
have  no  evidence,  however,  that  any  of  the  lower  animals  have  a  voluntary 
power  of  directing  their  mental  operations,  at  all  similar  to  that  which  Man 
possesses;  these  operations,  indeed,  seem  to  be  of  very  much  the  same  character 
as  those  which  we  perform  in  connected  dreams,  different  trains  of  thought  com- 
mencing as  they  are  suggested,  and  proceeding  according  to  the  usual  laws  until 
6ome  other  disturbs  them. — Although  it  is  customary  to  regard  the  Dog  and  the 
Elephant  as  the  most  intelligent  among  the  lower  animals,  it  is  not  certain  that 
we  do  so  with  justice ;  for  it  is  very  possible  that  we  are  misled  by  that  peculiar 
attachment  to  Man,  which  in  them  must  be  termed  an  instinct,  and  which  enters 
as  a  motive  into  a  large  proportion  of  their  actions;  and  that,  if  we  were  more 
acquainted  with  the  psychical  characters  of  the  higher  Quadrumana,  we  should 
find  in  them  a  greater  degree  of  mental  capability  than  we  now  attribute  to  them. 
One  thing  is  certain,  that  the  higher  the  degree  of  Intelligence  which  we  find 
characteristic  of  a  particular  race,  the  greater  is  the  degree  of  variation  which  we 
meet-with  in  the  characters  of  individuals;  thus  everybody  knows  that  there  are 
stupid  Dogs  and  clever  Dogs,  ill-tempered  Dogs -and  good-tempered  Dogs, — as 
there  are  stupid  Men  and  clever  Men,  ill-tempered  Men  and  good-tempered  Men. 
But  no  one  could  distinguish  between  a  stupid  Bee  and  a  clever  Bee,  or  between 
a  good-tempered  Wasp  and  an  ill-tempered  Wasp,  simply  because  all  their  actions 
are  prompted  by  an  unvarying  Instinct. 

573.  In  estimating  the  relative  development  of  the  Cerebrum  in  different 
tribes  of  Animals,  and  in  comparing  this  with  their  relative  Intelligence,  it  must 
be  borne  in  mind  that  the  size  of  the  organ  does  not,  considered  alone,  afford  a 
means  of  accurate  judgment  as  to  its  power.  For  the  quantity  of  vesicular 
matter  which  it  contains,  affords  the  only  fair  criterion  of  the  latter;  and  of 
this  we  must  judge,  not  merely  by  the  superficial  area,  but  by  the  number  and 
depth  of  the  convolutions,  and  by  the  thickness  of  the  cortical  layer.  Again, 
there  are  many  reasons  why  it  is  not  fair  to  estimate  the  relative  development 
of  the  Cerebrum  by  the  proportion  which  it  bears  to  the  whole  bulk  of  the 
animal ;  and,  on  the  whole,  the  most  accurate  basis  of  comparison  would  probably 
be  afforded  by  the  relation  between  the  bulk  of  the  Cerebrum  and  the  diameter  of 
the  Spinal  Cord  In  making  any  such  comparison,  however,  the  Thalami  Optici, 
Corpora  Striata,  and  Corpora  Quadrigemina  should  be  excluded  from  the  estimate, 
for  reasons  now  sufficiently  apparent;  and  the  bulk  of  the  Cerebrum  proper 
should  be  alone  determined,  either  by  weight,  or  by  the  displacement  of  liquid. 
But  the  Cerebrum  varies  in  different  classes  and  orders  of  Vertebrata,  not  merely 
in  proportional  size,  but  also  in  the  relative  development  of  its  anterior,  middle, 
and  posterior  lobes.  This  is  a  point  of  very  great  importance,  in  determining 
the  value  to  be  assigned  to  the  organological  system  of  Gall  and  Spurzheim  and 
their  followers.  The  Cerebrum  of  the  Oviparous  Vertebrata  is  not  a  miniature 
representative  of  that  of  Man,  as  a  whole,  but  only  of  his  anterior  lobes ;  as  is 
sufficiently  obvious  from  an  examination  of  its  connections  with  other  parts,  and 
from  the  absence  of  any  other  commissural  connections  between  its  two  hemi- 
spheres, than  those  which  are  afforded  by  the  Sensory  Ganglia.  It  is  in  the 
Iinplacental  Mammals,  that  we  find  the  first  rudiment  of  the  middle  lobes  of  the 
Cerebrum,  and  of  the  proper  inter-cerebral  commissure,  the  Corpus  Callosum ; 
and  even  in  the  Rodents  this  is  but  very  imperfectly  developed.  As  we  ascend 
the  Mammalian  series,  we  find  the  Cerebrum  becoming  more  and  more  elongated 
posteriorly,  by  the  development  of  the  middle  lobes,  and  the  inter-cerebral  com- 
missure becomes  more  complete ;  but  we  must  ascend  as  high  as  the  Carnivora, 
before  we  find  the  least  vestige  of  the  posterior  lobes;  and  the  rudiment  which 
these  possess,  and  which  is  enlarged  in  the  Quadrumana,,  only  attains  its  full 
development  in  Man,  in  whom  alone  the  posterior  lobes  extend  so  far  backwards 


THE    CEREBRUM,    AND    ITS    FUNCTIONS.  533 

as  completely  to  cover-in  the  Cerebellum.1 — The  attention  which  has  yet  been 
given  to  this  department  of  inquiry,  has  not  hitherto  done  more  than  confirm 
the  statement  already  made,  with  regard  to  the  general  correspondence  between 
the  development  of  the  Cerebrum  and  the  manifestations  of  Intelligence ;  very 
decided  evidence  of  which  is  furnished  by  the  great  enlargement  of  the  Cere-  ' 
bruin,  and  the  corresponding  alteration  in  the  form  of  the  Cranium,  which 
present  themselves  in  those  races  of  Dogs  most  distinguished  for  their  educability, 
when  compared  with  those  whose  condition  approximates  most  closely  to  what 
was  probably  their  original  state  of  wildness. 

574.  This  general  inference  drawn  from  Comparative  Anatomy,  is  borne-out 
by  observation  of  the  Human  species.  When  the  Cerebrum  is  fully  developed, 
it  offers  innumerable  diversities  of  form  and  size  among  various  individuals; 
and  there  are  as  many  diversities  of  character.  It  may  be  doubted  if  two  indi- 
viduals were  ever  exactly  alike  in  this  respect.  That  a  Cerebrum  which  is 
greatly  under  the  average  size,  is  incapable  of  performing  its  proper  functions, 
and  that  the  possessor  of  it  must  necessarily  be  more  or  less  idiotic,  there  can  be 
no  reasonable  doubt.  On  the  other  hand,  that  a  large  well-developed  Cerebrum 
is  found  to  exist  in  persons,  who  have  made  themselves  conspicuous  in  the  world 
in  virtue  of  their  intellectual  achievements,  may  be  stated  as  a  proposition  of 
equal  generality.  In  these  opposite  cases,  we  witness  most  distinctly  the  antago- 
nism between  the  Instinctive  and  Voluntary  powers.  Those  unfortunate  beings 
in  whom  the  Cerebrum  is  but  little  developed,  are  guided  almost  solely  by  their 
instinctive  tendencies,  which  frequently  manifest  themselves  with  a  degree  of 
strength  that  would  not  have  been  supposed  to  exist;  and  occasionally  new  in- 
stincts present  themselves,  of  which  the  Human  being  is  ordinarily  regarded  as 
destitute.2  On  the  other  hand,  those  who  have  obtained  most  influence  over  the 
understandings  of  others,  have  always  been  large-brained  persons,  of  strong  in- 
tellectual and  volitional  powers,  whose  emotional  tendencies  have  been  subor- 
dinated to  the  reason  and  will,  and  who  have  devoted  their  whole  energy  to  the  par- 
ticular objects  of  their  pursuit.  —  It  is  very  different,  however,  with  those  who 
are  actuated  by  what  is  ordinarily  termed  genius ;  and  whose  influence  is  rather 
upon  the  feelings  and  intuitions,  than  upon  the  understandings,  of  others.  Such 
persons  are  often  very  deficient  in  the  power  of  even  comprehending  the  ordinary 
affairs  of  life;  and  still  more  commonly,  they  show  an  extreme  want  of  judgment 
in  the  management  of  them,  being  under  the  immediate  influence  of  their  passions 
and  emotions,  which  they  do  not  sufficiently  endeavour  to  control  by  their  intel- 
ligent will.  The  life  of  a  '  genius/  whether  his  bent  be  towards  poetry,  music, 
painting,  or  pursuits  of  a  more  material  character,  is  seldom  one  which  can  be 
held-up  for  imitation.  In  such  persons,  the  general  power  of  the  mind  being 
low,  the  Cerebrum  is  not  usually  found  of  any  great  size. — The  mere  comparative 
size  of  the  Cerebrum,  however,  affords  no  accurate  measure  of  the  amount  of 
mental  power;  for  we  not  unfrequently  meet  with  men  possessing  large  and  well- 

1  It  has  been  asserted  by  the  followers  of  Gall,  that  the  development  of  the  Cerebrum 
from  behind  forwards,  as  above  described,  is  rather  apparent  than  real ;  the  whole  organ 
being  in  fact  pushed  backwards  by  the  excessive  development  of  the  anterior  lobe.     But 
the  anatomical  distinction  between  the  anterior  and  middle  lobes  is  sufficiently  obvious 
externally ;  and  that  of  the  middle  and  posterior  lobes  is  also  clearly  marked-out  by  the 
development  of  the  posterior  cornua  of  the  lateral  ventricles,  and  the  situation  of  the 
hippocampus  major.     Hence  the  facts  above  stated  do  not  admit  of  any  such  interpreta- 
tion; and  they  are  fully  borne-out  by  the  history  of  the  Embryonic  development  of  the 
Cerebrum  in  Man,  which  precisely  follows  the  above  plan. — It  is  not  here  denied  that  the 
anterior  lobe  of  the  Human  Cerebrum  is  remarkable  for  its  great  extension  forwards : 
but  still,  the  difference  between  the  Cerebrum  of  Man  and  that  of  the  lower  Mammalia 
consists  much  rather  in  the  proportional  development  of  the  posterior  lobe.s,  than  in  that 
of  the  anterior. 

2  A  remarkable  instance  of  this  was  published  some  years  since :  —  A  perfectly  idiotic 
girl,  in  Paris,  having  been  seduced  by  some  miscreant,  was  delivered  of  a  child  without 
assistance;  and  it  was  found  that  she  had  gnawed  the  umbilical  cord  in  two,  in  the  «anae 
manner  as  is  practised  by  the  lower  animals.     It  is  scarcely  to  be  supposed  that  she  had 
any  idea  of  the  object  of  this  separation. 


534  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

formed  heads,  whose  psychical  capability  is  not  greater  than  that  of  others,  the 
dimensions  of  whose  crania  have  the  same  general  proportion,  but  are  of  much 
less  absolute  size.  Large  brains,  with  deficient  activity,  are  commonly  found  in 
persons  of  what  has  been  termed  the  phlegmatic  temperament,  in  whom  the 
general  processes  of  life  seem  in  a  torpid  and  indolent  state ;  whilst  small  brains 
and  great  activity,  betoken  what  are  known  as  the  sanguine  and  nervous  tempe- 
raments. 

575.  Having  now  inquired  into  the  evidence  of  the  general  functions  of  the 
Cerebrum,  which  may  be  derived  from  examination  of  its  Comparative  develop- 
ment, we  proceed  to  our  other  sources  of  information,  Experiment  and  Patho- 
logical phenomena.  From  neither  of  these,  however,  is  much  positive  informa- 
tion to  be  derived.  —  All  the  results  of  experiments  concur  to  establish  the  fact, 
that  no  irritation,  either  of  the  vesicular  or  of  the  fibrous  substance,  produces 
either  sensation  or  motion.  These  results  are  borne-out  by  pathological  observa- 
tions in  Man  ;  for  it  has  been  frequently  remarked,  when  it  has  been  necessary 
to  separate  protruded  portions  of  the  Brain  from  the  remainder,  that  this  has 
given-rise  to  no  sensation,  eve,n  in  cases  in  which  the  mind  has  been  perfectly 
clear  at  the  time,  nor  has  any  convulsive  action  been  produced.  The  results  of 
partial  mutilations  are  usually,  in  the  first  instance,  a  general  disturbance  of  the 
Cerebral  functions ;  which  subsequently,  however,  more  or  less  quickly  subsides, 
leaving  but  little  apparent  affection  of  the  animal  functions,  except  muscular 
weakness.  The  whole  of  one  Hemisphere  has  been  removed  in  this  way,  with- 
out any  evident  consequence,  save  a  temporary  feebleness  of  the  limbs  on  the 
opposite  side  of  the  body,  and  what  was  supposed  to  be  a  deficiency  of  sight 
through  the  opposite  eye.  The  former  was  speedily  recovered-from,  and  the 
animal  performed  all  its  movements  as  well  as  before;  the  latter,  however,  was 
permanent,  but  the  pupil  remained  active.  When  the  upper  part  only  of  both 
Cerebral  Hemispheres  was  removed  by  Hertwig,  the  animal  was  reduced,  for 
fifteen  days,  to  nearly  the  same  condition  with  the  one  from  which  they  had  been 
altogether  withdrawn;  but  afterwards,  sensibility  evidently  returned,  and  the 
muscular  power  did  not  appear  to  be  much  diminished. — The  effects  of  the  entire 
removal  of  the  Cerebral  Hemispheres  have  been  already  stated  (§  529).  So  far 
as  any  inferences  can  be  safely  drawn  from  them,  these  fully  bear  out  the  conclu- 
sion that  the  Cerebrum  is  the  organ  of  Intelligence ;  since  the  animals  which 
have  suffered  this  mutilation  appear  to  be  constantly  plunged  in  a  profound  sleep, 
from  which  no  irritation  ever  seems  able  to  arouse  them  into  full  activity,  although 
they  give  manifestations  of  consciousness.  It  would  be  wrong  hence  to  infer, 
however,  as  some  have  done,  that  such  would  be  the  natural  condition  of  an 
animal  without  a  Cerebrum  ;  since  it  is  obvious  that  much  of  the  disturbance  of 
the  sensorial  powers  which  is  occasioned  by  this  operation,  is  fairly  attributable 
to  the  laying-open  of  the  cranial  cavity,  to  the  disturbance  of  the  normal  vascu- 
lar pressure,  and  to  the  injury  necessarily  done  to  the  parts  which  are  left,  by 
their  severance  from  the  Cerebrum.  Hence  the  persistence  of  consciousness, 
after  the  entire  removal  of  the  Cerebrum,  —  which  proves  that  the  Cerebrum  is 
not  its  seat,  or  at  least  not  its  exclusive  seat,  —  is  a  far  more  important  fact  than 
the  positive  destruction  of  psychical  power  which  is  consequent  upon  the  opera- 
tion. So  far  as  they  can  be  trusted,  however,  the  results  of  such  mutilations 
bear-out  the  views  already  put-forth,  as  to  the  superadded  and  non-essential  cha- 
racter of  the  Cerebrum ;  and  justify  us  in  applying  to  the  higher  animals  the  in- 
ferences to  which  we  should  be  led  by  the  contemplation  of  those  forms  of  the 
nervous  system  in  which  no  Cerebrum  exists.  There  is  nothing,  therefore,  to 
oppose  the  conclusion,  that  whilst  sensations  may  be  felt,  and  sensori-motor 
actions  excited,  independently  of  the  Cerebrum,1  the  presence  of  this  organ  is 

1  It  is  worthy  of  remark,  that  M.  Flourens,  who  in  the  first  instance  maintained  that 
eensation  is  altogether  destroyed  by  the  removal  of  the  Cerebrum,  has  substituted,  in  the 
Second  Edition  of  his  Researches,  the  word  perception  for  sensation;  apparently  implying 
exactly  what  is  maintained  above. 


THE    CEREBRUM,     AND    ITS    FUNCTIONS.  535 

essential  to  the  formation  of  ideas  or  notions  respecting  the  objects  of  sense,  and 
to  the  performance  of  those  psychical  operations  for  which  ideas  furnish  at  once 
the  material  and  the  stimulus  to  activity. 

576.  The  information  aiforded  by  Pathological  phenomena  is  equally  far  from 
being  definite.     Many  instances  are  on  record,  in  which  extensive  disease  has 
occurred  in  one  Hemisphere,  so  as  almost  entirely  to  destroy  it,  without  either 
any  obvious  injury  to  the  mental  powers,  or  any  interruption  of  the  influence  of 
the  mind  upon  the  body.     But  there  is  no  case  on  record,  of  any  such  severe 
lesion  of  both  hemispheres,  in  which  morbid  phenomena  were  not  evident  during 
life.     It  is  true  that,  in  Chronic  Hydrocephalus,  a  very  remarkable  alteration  in 
the  condition  of  the  Brain  sometimes  presents  itself,  which  might  d  priori  have 
been  supposed  destructive  to  its  power  of  activity;  the  ventricles  being  so  enor- 
mously distended  with  fluid,  that  the  cerebral  matter  has  seemed  like  a  thin 
lamina,  spread  over  the  interior  of  the  enlarged  cranium.     But  there  is  no  proof 
that  absolute  destruction  of  any  part  was  thus  occasioned;   and  it  would  seem 
that  the  very  gradual  nature  of  the  change,  gives  to  the  structure  time  for  accom- 
modating itself  to  it.     This,  in  fact,  is  to  be  noticed  in  all  diseases  of  the  Ence- 
phalon.     A  sudden  lesion,  that  may  be  so  trifling  as  to  escape  observation,  unless 
this  be  very  carefully  conducted,  will  occasion  very  severe  symptoms ;    whilst  a 
chronic  disease  may  gradually  extend  itself,  without  any  external  manifestation. 
It  will  usually  be  found  that  sudden  paralysis,  of  which  the  seat  is  in  the  Brain, 
results  from  some  slight  effusion  of  blood  in  the  substance  or  in  the  neighbour- 
hood of  the  Corpora  Striata;  whilst,  if  it  follow  disorder  of  long  standing,  a  much 
greater  amount  of  lesion  commonly  presents  itself.     In  either  case,  the  paralysis 
occurs  in  the  opposite  side  of  the  body,  as  we  should  expect  from  the  decussation 
of  the  Pyramids ;  but  it  may  occur  either  on  the  same,  or  on  the  opposite  side 
of  the  face, — the  cause  of  which  is  not  very  apparent.     If  convulsions  accompany 
the  paralysis,  we  may  infer  that  the  Corpora  Quadrigemina,  or  the  parts  below, 
are  involved  in  the  injury;  and  in  this  case  it  is  usually  found  that  the  convul- 
sions are  on  the  paralysed  side  of  the  body, — the  effect  of  the  lesion,  both  of  the 
Cerebrum  and  of  the  Corpora  Quadrigemina,  being  propagated  to  the  opposite 
side,  by  the  decussation  of  the  Pyramids.     Where,  as  not  unfrequently  happens, 
there  is  paralysis  of  one  side,  accompanying  convulsions  on  the  other,  it  is  com- 
monly the  result  of  a  lesion  affecting  the  base  of  the  Brain  and  Medulla  Oblongata, 
on  the  side  on  which  the  convulsions  take  place ;   here  the  effect  of  the  lesion 
has  to  cross  from  the  Brain,  whilst  its  influence  on  the  Medulla  Oblongata  is  shown 
on  the  same  side.     Many  anomalies  present  themselves,  however,  which  are  by 
no  means  easy  of  explanation,  in  the  present  state  of  our  knowledge. — The  dis- 
turbance of  the  Cerebral  functions,  occasioned  by  those  changes  in  its  nutrition 
which  are  commonly  included  under  the  general  term  Inflammation,  presents  a 
marked  diversity  of  character,  according  to  the  part  it  affects.     Thus  it  is  well 
known  that  the  Delirium  of  excitement  is  usually  a  symptom  of  inflammation  of 
the  cortical  substance,  or  of  the  membranes,  of  the  Hemispheres.     This  is  exactly 
what  might  be  anticipated  from  the  foregoing  premises,  since  this  condition  is  a 
perversion  of  the  ordinary  mental  operations,  which  are  dependent  upon  the 
instrumentality  of  the  vesicular  matter :  and  it  is  evidently  impossible  for  the 
membranes  to  be  affected  with  inflammation,  without  the  nutrition  of  this  sub- 
stance being  impaired,  since  it  derives  all  its  vessels  directly  from  them.     On  the 
other  hand,  inflammation  of  the  fibrous  portion  of  the  Cerebrum  is  usually  attended 
rather  with  a  state  of  torpor,  than  with  excitement;  and  with  diminished  power 
of  the  will  over  the  muscles.     It  is  stated  by  Foville,  that  in  acute  cases  of 
Insanity,  he  has  usually  found  the  cortical  substance  intensely  red,  but  without 
adhesion  to  the  membranes;    whilst  in  chronic  cases,  it  is  indurated  and  adhe- 
rent :  but  where  the  insanity  has  been  complicated  with  Paralysis,  he  has  usually 
found  the  medullary  portion  indurated  and  congested. 

577.  The  general  result  of  such  investigations  is;  that  the  Cerebrum  is  ths 


536  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

instrument  of  all  those  psychical  operations,  which  we  include  under  the  general 
term  Intellectual,  whilst  it  also  affords,  in  part  at  least,  the  instrumental  con- 
ditions of  Emotional  states;  and  that  all  those  muscular  movements  which  result 
from  voluntary  determinations,  or  which  are  directly  consequent  upon  emotional 
excitement,  have  their  origin  in  its  vesicular  substance,  though  the  motor  impulse 
is  immediately  furnished  by  the  Cranio-Spinal  apparatus,  upon  which  the  Cere- 
brum plays  (§  550).  It  does  not  hence  follow,  however,  that  the  Cerebrum  has 
such  a  direct  relation  to  the  Mind,  that  the  consciousness  is  immediately  and 
necessarily  affected  by  changes  taking-place  in  its  own  substance ;  and,  however 
startling  the  proposition  may  at  first  sight  appear,  that  the  organ  of  the  intel- 
lectual operations  is  not  itself  endowed  with  consciousness,  a  careful  considera- 
tion of  the  relations  of  the  Cerebrum  to  the  Sensory  Ganglia  will  tend  to  show 
that  there  is  no  d  priori  absurdity  in  such  a  notion.  For  if  the  connection  of  the 
vesicular  matter  of  the  Cerebral  Hemispheres  with  the  Sensorial  Centres,  be  ana- 
tomically the  same  as  that  which  exists  between  these  centres  and  the  Retina  or 
any  other  peripheral  expansion  of  vesicular  matter  in  an  organ  of  sense,  which 
we  have  seen  that  it  is  (§  566), — and  if  the  same  kind  of  change  may  be  excited 
in  the  Sensorial  Centres  by  an  impression  from  each  source,  which  has  been 
shown  to  be  a  matter  of  common  occurrence  (§  549), — it  can  scarcely  be  deemed 
unlikely  that  the  Sensorial  Centres  should  be  the  seat  of  consciousness,  not  merely 
for  the  impressions  transmitted  to  them  by  the  nerves  of  the  external  senses,  but 
also  for  the  impressions  brought  to  them  by  the  l  nerves  of  the  internal  senses/ 
as  we  may  designate  (after  Reil)  the  radiating  fibres  of  the  Cerebral  Hemispheres 
(§  566).  And  there  is  on  the  other  hand  an  d  priori  improbability  that  there 
should  be  two  seats  of  consciousness,  so  far  removed  from  one  another  as  the 
Sensory  Ganglia  and  the  vesicular  surface  of  the  Hemispheres  (for  to  their  medul- 
lary substance  no  such  attribute  can  be  assigned  with  the  least  probability);  an 
idea  which  is  quite  at  variance  with  that  very  simple  and  familiar  class  of  phe- 
nomena, which  consists  in  the  recollection  of  sensations  (§  591).  For  the  remem- 
bered sensation  is  so  completely  the  reproduction  of  the  original,  that  we  can 
hardly  suppose  the  seat  of  the  two  to  be  different ;  yet  the  act  of  recollection  is 
clearly  Intellectual,  and  therefore  Cerebral;  consequently,  if  we  admit  that  the 
Sensory  Ganglia  are  the  seat  of  the  original  sensation,  we  can  scarcely  but  admit 
that  they  are  also  the  seat  of  that  which  is  reproduced  by  a  Cerebral  act, — a  view 
which  is  fully  confirmed  by  the  occurrence  of  automatic  movements  as  conse- 
quences of  its  recall  (§  549).  But  further,  we  shall  hereafter  find  evidence  to 
the  same  effect,  in  our  experience  of  the  occasional  evolution  of  results,  such  as 
ordinarily  proceed  from  intellectual  action,  without  any  consciousness  on  our  own 
parts  of  the  steps  whereby  these  are  attained  (§§  652-654). 

578.  Without  presuming,  then,  to  affirm  positively  what  cannot  be  proved,  it 
may  be  stated  as  a  probable  inference  from  the  Physiological  facts  already  referred- 
to,  and  from  the  Psychological  evidence  hereafter  to  be  adduced,  that  the  Sensory 
Ganglia  constitute  the  seat  of  consciousness,  not  merely  for  impressions  on  the 
Organs  of  Sense,  but  also  for  changes  in  the  cortical  substance  of  the  Cerebrum ; 
so  that,  until  the  latter  have  reacted  downwards  upon  the  Sensorium,  we  have 
no  consciousness  either  of  the  formation  of  ideas,  or  of  any  intellectual  process 
of  which  these  may  be  the  subjects. — Ideas,  Emotions,  Intellectual  operations, 
&c.,  have  of  late  been  frequently  designated  as  '  states  of  consciousness ;'  and  this 
psychological  description  of  them  is  in  full  harmony  with  the  physiological  account 
here  given  of  the  material  conditions  under  which  they  respectively  occur.  For 
as  a  Sensation  is  a  state  of  consciousness  excited  through  the  instrumentality  of 
the  Sensorium,  by  a  certain  change  (e.  g.}  in  the  condition  of  the  Retina,  it  is 
not  difficult  to  understand  how  a  change  in  the  condition  of  the  Cerebrum  may 
excite,  through  the  same  instrumentality,  that  state  of  consciousness  which  may 
be  termed  Ideational,1  or  that  another  change  may  produce  the  Emotional  con- 

1  The  Author  ventures  to  use  this  term,  the  meaning  of  which  requires  no  explanation, 
?n  the  authority  of  Mr.  James  Mill,  "who  remarks, — "As  we  say  Sensation,  we  might  also 


CORRELATION    OF    PHYSIOLOGICAL    AND    PSYCHICAL    ACTION.      537 

scicusness,  another  the  Intuitional  consciousness,  another  the  Logical  conscious- 
ness. And  although  it  may  be  thought  at  first  sight  to  be  a  departure  from  the 
simplicity  of  Nature,  to  suppose  that  the  Cerebrum  should  require  another  organ 
to  give  us  a  consciousness  of  its  operations,  yet  we  have  the  knowledge  that  the 
Eve  does  not  give  us  visual  consciousness,  nor  the  Ear  auditory  consciousness, 
unless  they  be  connected  with  the  Sensory  Ganglia;  and  in  the  end  (the  Author 
feels  a  strong  assurance)  it  will  be  found  much  simpler  to  accept  the  doctrine  of 
a  common  centre  for  sensational  and  for  what  may  be  distinguished  as  mental 
consciousness,  than  to  regard  the  two  centres  as  distinct.1 — We  shall  now  proceed 
with  a  brief  analysis  of  the  Mental  phenomena,  of  which  the  Sensory  Ganglia 
and  the  Cerebrum  afford  the  material  instruments;  looking  at  these,  however, 
rather  from  their  physiological  than  from  their  psychological  side. 

6.    Of  the  Mind,  and  its  Operations. 

579.  Correlation  of  Physiological  and  Psychical  Action. — It  is  universally 
admitted  that,  notwithstanding  all  the  diversities  of  Human  character  and  Mental 
action,  there  are  certain  fundamental  uniformities  which  may  be  traced  through- 
out the  whole  of  this  series ;  and  it  is  on  the  basis  afforded  by  these,  that  the 
Science  of  Psychology  is  erected,  to  which  may  be  applied,  with  a  mere  altera- 
tion of  form,  the  definition  elsewhere  given  of  Physiology  (PmNC.  OF  GEN.  PHYS., 
Am.  Ed.,  p.  1). — "The  object  of  the  science  of  Psychology  is  to  bring  together, 
in  a  systematic  form,  the  phenomena  which  normally  present  themselves  during 
the  existence  of  thinking  minds;  and  to  classify  and  compare  these  in  such  a  man- 
ner, as  to  deduce  from  them  those  general  Laws  or  Principles  which  express  the 
conditions  of  their  occurrence,  and  to  determine  the  causes  to  which  they  are 
attributable/'  As  our  present  object,  however,  is  not  so  much  to  investigate  the 
operations  of  the  Mind  itself,  as  to  consider  their  relations  to  those  of  the  bodily 
Organism,  we  shall  here  enter  into  the  examination  of  the  nature  and  laws  of 
psychical  phenomena,  only  so  far  as  may  be  requisite  for  the  elucidation  of  that 
mutual  action  and  reaction,  which  is  continually  taking-place  between  these  two 
parts  of  our  nature.  To  the  prevalent  neglect  of  this  department  of  study,  may 
be  traced  many  of  the  fallacies  discernible  in  the  arguments  adduced  on  each 
side,  in  the  oft-repeated  controversies  between  the  advocates  of  the  Materialist 
and  the  Spiritualist  hypotheses; — controversies  in  themselves  almost  as  absurd 
as  that  mortal  contest  which  (fable  tells  us)  was  once  carried-on  by  two  knights 
respecting  the  material  of  a  shield  which  they  saw  from  opposite  sides,  the  one 
maintaining  it  to  be  made  of  gold,  the  other  of  silver,  and  each  proving  to  be  in 
the  right  as  regarded  the  half  seen  by  himself.  Now  the  moral  of  this  fable,  as 
regards  our  present  enquiry,  is,  that  as  the  entire  shield  was  really  made-up  of  a 
gold-half  and  a  silver-half  which  joined  each  other  midway,  so  the  Mind  and  the 
Brain,  notwithstanding  those  differences  in  properties  which  place  them  in  dif- 
ferent philosophical  categories,  are  so  intimately  blended  in  their  actions,  that 
more  valuable  information  is  to  be  gained  by  seeking  for  it  at  the  points  of  con- 
tact, than  can  be  obtained  by  the  prosecution  of  those  older  methods  of  research, 
in  which  Mind  has  been  studied  by  Metaphysicians  altogether  without  reference 
to  its  material  instruments,  whilst  the  Brain  has  been  dissected  by  Anatomists 

say  Ideation ;  it  would  be  a  very  useful  word ;  and  there  is  no  objection  to  it,  except  the 
pedantic  habit  of  decrying  a  new  term.  Sensation  is  the  general  name  for  one  part  of 
our  constitution  [or  rather,  for  one  state  of  our  consciousness],  Ideation  for  another." 
("  Aualysi^  of  the  Human  Mind,"  vol.  i.  p.  42.) — If  the  use  of  the  substantive  Ideation  be 
admitted,  there  can  be  no  reasonable  objection  to  the  adjective  ideational. 

1  It  may  serve  to  give  additional  confidence  in  the  views  above  propounded,  if  the 
Author  mentions  thai  he  was  lead  by  them  to  predict  the  psychological  phenomena  refer- 
red-to  at  the  end  of  §  577,  of  which  he  was  not  at  the  time  aware  as  facts,  but  of  which 
he  afterwards  became  assured  by  the  analysis  of  his  own  consciousness,  and  by  the  com 
muuicated  experieuce  of  others  to  whom  he  stated  the  question. 


638  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

and  analyzed  by  Chemists,  as  if  they  expected  to  map-out  the  course  of  Thought, 
or  to  weigh  or  measure  the  intensity  of  Emotion.1 

580.  Although  few  (if  any)  Philosophers  would  be  disposed  to  question  that 
the  Cerebrum  is  the  instrument  of  our  higher  psychical  powers,  the  ideas  which 
are  entertained  of  the  nature  of  this  instrumentality  have  been  seldom  clearly  or 
consistently  defined.  Some,  who  have  attended  exclusively  to  the  close  relation- 
ship which  indubitably  exists  between  corporeal  and  mental  states,  have  thought 
that  all  the  operations  of  the  Mind  are  but  manifestations  or  expressions  of  ma- 
terial changes  in  the  Brain  •  that  thus  Man  is  but  a  thinking  machine,  his  con- 
duct being  entirely  determined  by  his  original  constitution,  modified  by  subsequent 
conditions  over  which  he  has  no  control,  and  his  fancied  power  of  self- direction 
being  altogether  a  delusion ;  and  hence  that  notions  of  duty  or  responsibility 
have  no  real  foundation,  Man's  character  being  formed  for  him,  and  not  by  him, 
and  his  mode  of  action  in  each  individual  case  being  simply  the  consequence  of 
the  reaction  of  his  Cerebrum  upoii  the  impressions  which  called  it  into  play. 
On  this  creed,  what  is  commonly  termed  Criminality  is  but  one  form  of  Insanity, 
and  ought  to  be  treated  as  such ;  Insanity  itself  is  nothing  else  than  a  disordered 
action  of  the  Brain;  and  the  highest  elevation  of  Man's  psychical  nature  is  to 
be  attained  by  due  attention  to  all  the  conditions  which  favour  his  physical  de- 
velopment.2— Now  this  honestly-expressed  Materialist  doctrine  recognises  certain 
great  facts,  on  which  the  unprejudiced  and  observant  Physiologist  can  scarcely 
entertain  a  doubt,  notwithstanding  that  their  validity  may  be  denied  by  those 
who  have  had  comparatively  little  opportunity  of  studying  them,  or  who  have  so 
made  up  their  minds  to  a  foregone  conclusion,  as  to  be  ready  to  admit  nothing 
which  is  not  in  accordance  with  it.  The  whole  serigs  of  phenomena  which  so 

1  This  inquiry  has  been  started  more  than  once,  but  has  not  until  recently  been  sys- 
tematically prosecuted.  "  There  is  one  view  of  the  connection  between  Mind  and  Matter, 
says  Prof.  Dugald  Stewart,  "  which  is  perfectly  agreeable  to  the  just  rules  of  philosophy. 
The  object  of  this  is,  to  ascertain  the  laws  which  regulate  their  union,  without  attempting 
to  explain  in  what  manner  they  are  united.  Lord  Bacon,  was,  I  believe,  the  first  who 
gave  a  distinct  idea  of  this  kind  of  speculation ;  and  I  do  not  know  that  much  progress 
has  yet  been  made  in  it." — Considering  his  own  province,  however,  to  be  purely  Meta- 
physical, the  eminent  Professor  just  quoted  gave  no  further  attention  to  the  subject  thus 
adverted-to ;  and  those  who  have  more  recently  taken  it  up,  having  been  Physiologists 
and  Physicians,  rather  than  professed  Psychologists,  have  been  looked-upon  by  the  latter 
as  opponents  rather  than  as  allies.  It  is  much  to  be  desired  that  a  systematic  study 
should  be  made,  by  those  whose  mental  training  and  habits  of  scientific  research  qualify 
them  for  the  task,  of  that  wide  and  almost  unexplored  domain,  which  comprehends  the 
whole  range,  not  only  of  what  may  be  termed  Menial  Physiology,  but  also  of  Menial  Patho- 
logy, and,  in  addition,  the  Comparative  Psychology  of  the  lower  Animals,  and  the  History 
of  Development  of  the  Human  Mind,  from  the  earliest  manifestation  of  its  powers. 

a  For  the  latest  and  most  thorough-going  expression  of  this  doctrine,  see  the  "  Letters 
on  the  Laws  of  Man's  Nature  and  Development,"  by  Henry  G.  Atkinson  and  Harriet 
Martineau.  A  few  extracts  will  suffice  to  show  the  bearings  of  this  system  of  philosophy. 
"Instinct,  passion,  thought,  &c.  are  effects  of  organized  substances."  "All  causes  are 
material  causes."  "  In  material  conditions  I  find  the  origin  of  all  religions,  all  philoso- 
phies, all  opinions,  all  virtues,  and  '  spiritual  conditions  and  influences,'  in  the  same  man- 
ner that  I  find  the  origin  of  all  diseases  and  of  all  insanities  in  material  conditions  and 
causes."  "  I  am  what  I  am  :  a  creature  of  necessity;  I  claim  neither  merit  nor  demerit." 
**  I  feel  that  I  am  as  completely  the  result  of  my  nature,  and  impelled  to  do  what  I  do,  as 
the  needle  to  point  to  the  north,  or  the  puppet  to  move  according  as  the  string  is  pulled." 
"  I  cannot  alter  my  will,  or  be  other  than  what  I  am,  and  cannot  deserve  either  reward  or 
punishment." — It  seems  to  the  Author,  that  every  system  of  Philosophy  which  regards 
the  succession  of  Mental  Phenomena  as  determined  solely  by  the  ordinary  laws  of  Causa 
tion,  and  which  rejects  the  self-determining  power  of  the  Will  (or,  which  is  the  sam 
thing,  regards  the  Will  as  only  another  expression  for  the  preponderance  of  motives] 
virtually  leads  to  the  same  result.  On  this  account,  he  cannot  admit  that  Mr.  John  Mill's 
'  Logic  of  the  Moral  Sciences'  (Book  vi.  of  his  "  System  of  Logic") — masterly  though  it 
be,  as  an  exposition  of  the  method  of  investigating  that  part  of  our  psychical  nature 
which  can  be  brought  within  the  domain  of  Law, — is  applicable  to  the  Human  Mind  at  a 
whole. 


COKRELATION    OF    PHYSIOLOGICAL    AND    PSYCHICAL    ACTIONS.       539 

plainly  mark  the  influence  of  the  Body  on  the  Mind,  of  physical  upon  psychical 
states, — the  obvious  dependence  of  the  normal  activity  of  the  Mind  upon  the 
healthful  nutrition  of  the  Brain,  and  upon  its  due  supply  of  oxygenated  blood, — 
the  extraordinary  influence  of  local  affections  of  the  Cerebrum  upon  the  normal 
succession  of  Intellectual  operations,  as  is  especially  seen  in  the  strange  disturb- 
ances or  '  dislocations '  of  the  memory  consequent  upon  blows  on  the  head, — the 
large  share  which  certain  states  of  bodily  disorder  on  the  part  of  parents,  or 
conditions  tending  to  induce  defective  nutrition  during  the  periods  of  infancy 
and  childhood,  have  been  proved  to  possess  in  the  induction  of  Idiocy  and  Cre- 
tinism,— the  complete  perversion  of  all  the  mental  powers  and  moral  feelings, 
amounting  to  a  temporary  insanity,  which  is  produced  by  Intoxicating  agents, — 
these  and  numerous  other  phenomena  might  be  cited  in  support  of  the  Materialist 
doctrine ;  and  must  be  accounted-for  by  any  one  who  undertakes  the  solution  of 
this  mystery. 

581.  But  these  phenomena  are  not  to  be  looked-at,  to  the  exclusion  of  the  facts 
of  our  own  internal  consciousness.     In  reducing  the  Thinking  Man  to  the  level 

•of  "a  puppet  that  moves  according  as  its  strings  are  pulled,"  the  Materialist  Phi- 
losopher places  himself  in  complete  opposition  to  the  undoubting  conviction  which 
almost  every  one  feels,  who  does  not  trouble  himself  by  speculating  upon  the 
matter,  that  he  really  possesses  a  self-determining  power,  which  can  rise  above 
all  the  promptings  of  external  suggestion,  and  can,  to  a  certain  extent,  mould  ex- 
ternal circumstances  to  its  own  requirements,  instead  of  being  completely  subju- 
gated by  them.  We  can  scarcely  desire  a  better  proof  that  our  possession  of 
this  power  is  a  reality  and  not  a  self-delusion,  than  that  which  is  afforded  by  the 
comparison  of  the  normal^condition  of  the  mind,  with  that  in  which  the  directing 
power  of  the  Will  is  in  abeyance.  This  last  condition  is  seen  in  certain  states  of 
Somnambulism,  both  natural  and  artificial  (§§  693-695),  in  the  'Biologized' 
state  (§  672),  and  in  some  other  abnormal  conditions;  the  subjects  of  which  may 
really  be  considered  (so  long  as  those  conditions  are  allowed  to  last)  as  mere 
thinking  automata,  puppets  pulled  by  directing  strings;  their  whole  course  of 
thought  and  of  action  being  determined  by  suggestions  conveyed  from  without, 
and  their  own  Will  having  no  power  to  modify  or  direct  this,  owing  to  the  tem- 
porary suspension  of  its  influence. — To  whatever  extent,  then,  we  may  be  ready 
to  admit  the  dependence  of  our  mental  operations  upon  the  organization  and  func- 
tional activity  of  our  Nervous  System,  we  cannot  but  feel  that  there  is  something 
beyond  and  above  all  this,  to  which,  in  the  fully- developed  and  self-regulating 
mind,  that  activity  is  subordinated ;  whilst,  in  rudely  trampling  on  the  noblest 
conceptions  of  our  nature  as  mere  delusions,  the  Materialist  hypothesis  is  so  tho- 
roughly repugnant  to  the  almost  intuitive  convictions  which  we  draw  from  the 
simplest  application  of  our  Intelligence  to  our  own  Moral  Sense,  that  those  who 
have  really  experienced  these,  are  made  to  feel  its  essential  fallacies  with  a  cer- 
tainty that  renders  logical  proof  quite  unnecessary. 

582.  Let  us  turn  now  to  the  opposite  doctrine  held  by  the  Spiritualists,  in 
regard  to  the  nature  and  source  of  mental  phenomena;  and  consider  this  in  its 
Physiological  relations.     To  them  the  Mind  appears  in  the  light  of  a  separate 
immaterial  existence,  mysteriously  connected,  indeed,  with  a  bodily  instrument, 
but  not  dependent  upon  this  in  any  other  way  for  the  conditions  of  its  operation, 
than  as  deriving  its  knowledge  of  external  things  through  its  agency,  and  as 
making  use  of  it  to  execute  its  determinations,  so  far  as  these  relate  to  material 
objects.     On  this  hypothesis,  the  operations  of  the  Mind  itself,  having  no  rela- 
tion whatever  to  those  of  Matter,  are  never  themselves  affected  by  conditions  of 
the  corporeal  organism,  whose  irregularities  or  defects  of  activity  only  pervert  01 
obscure  the  outward  manifestations  of  the  Mind,  just  as  the  light  of  the  brightest 
lamp  may  be  dimmed  or  distorted  by  passing  through  a  bad  medium;  and,  fu-r- 
ther,  as  the  Mind  is  thus  independent  of  its  material  tenement,  and  of  the  circum- 
stances in  which  this  may  chance  to  be  placed,  but  is  endowed  with  a  complete 


540  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

power  of  self-government,  it  is  responsible  for  all  its  own  actions,  which  must  1> 
judged-of  by  certain  fixed  standards.  Now  this  doctrine  fully  recognizes  all  that 
is  ignored  in  the  preceding ;  but,  on  the  other  hand,  it  ignores  all  that  it  recog- 
nized and  served  to  account-for;  and  is  not  less  opposed  to  facts  of  most  familiar 
experience.  For  in  placing  the  Mind  outside  of  the  body  (so  to  speak),  and  in 
denying  that  the  action  of  the  Mind  itself  is  ever  disordered  by  corporeal  condi- 
tions, it  puts  us  in  the  dilemma  of  either  rejecting  the  plainest  evidence,  or  of 
admitting  that,  after  all,  we  know  nothing  whatever  about  the  Mind  itself;  all 
that  we  do  know,  being  that  lower  part  of  our  mental  nature  which  operates  on 
the  body,  and  is  in  its  turn  affected  through  it. — Those  who  most  fully  and  con- 
sistently carry-out  this  doctrine,  are  ready  to  maintain  that  even  in  the  state  of 
Intoxication  there  is  no  truly  mental  perversion;  and  that,  in  spite  of  appearances, 
the  mind,  of  the  Lunatic  (divinae  particula  aurse)  is  perfectly  sound,  its  bodily 
instrument  being  alone  disordered.  But  it  cannot  be  overlooked,  that  in  the  de- 
lirious ravings  of  Intoxication  or  of  Fever,  or  in  the  conversation  and  actions  of 
the  Lunatic,  we  have  precisely  the  same  evidence  of  mental  operation,  that  we 
have  in  the  sayings  and  doings  of  the  same  individuals  in  a  state  of  sanity;  and' 
ample  testimony  to  this  effect  is  borne  by  those,  who  have  observed  their  own 
mental  state  during  the  access  of  these  conditions,  and  who  have  described  the 
alteration  which  takes  place  in  the  course  of  their  thoughts,  when  as  yet  neither 
the  sensorial  nor  the  motor  apparatus  was  in  the  least  perturbed.1  Nothing,  we 
think,  can  be  more  plain  to  the  unprejudiced  observer,  than  that  the  introduction 
of  Intoxicating  agents  into  the  circulating  system  really  perverts  the  action  of 
the  mind,  disordering  the  usual  sequence  of  phenomena  most  purely  psychical, 
and  occasioning  new  and  strange  results  which  are  altogether  at  variance  with 
those  of  its  normal  action.  And  when  once  the  reality  of  this  influence  of  phy- 
sical conditions  upon  purely-mental  states  is  forced  upon  the  Physiologist,  he  can 
scarcely  refrain  from  attributing  to  it  a  very  wide  range  of  action ;  and  thus  he 
is  led  to  the  conviction,  that  however  true  it  may  be,  that  there  is  something  in 
our  mental  constitution  beyond  and  above  any  agency  which  can  be  attributed  to 
Matter,  the  operations  of  the  Mind  are  in  a  great  degree  determined  (in  our  pre- 
sent state  of  being)  by  the  material  conditions  with  which  they  are  so  intimately 
associated. 

583.  The  whole  theory  and  practice  of  Education,  indeed,  involves  the  distinct 
recognition  of  external  influences,  as  having  a  most  important  share  in  the  forma- 
tion of  the  character;  whilst  it  is  the  object  of  every  enlightened  Educator  to 
foster  the  development,  and  to  promote  the  right  exercise,  of  that  power  by  which 
each  individual  becomes  the  director  of  his  own  conduct,  the  arbiter  of  his  own 
destinies.  It  may  be  considered  as  a  legitimate  deduction  from  experience,  that 
until  this  self-directing  power  has  been  acquired,  the  character  is  the  resultant 
of  original  constitution,  and  of  the  circumstances  in  which  the  individual  is 
placed ;  and  that  so  long  as  the  circumstances  are  unfavourable  to  the  develop- 
ment of  the  self-directing  power,  and  to  the  operation  of  those  higher  tendencies 
which  should  furnish  the  best  motives  to  its  exercise,  so  long  the  character  of  the 
individual  is  formed  for  him  and  not  by  him.  The  real  self-formation  com- 
mences with  his  consciousness  of  the  possession  of  that  power  which  enables  him 
to  determine  his  own  course  of  thought  and  action ;  a  power  which  is  exercised 
by  the  Will,  in  virtue  of  its  domination  over  what  may  be  designated  as  the  auto- 
matic operation  of  the  Mind.  A  being  entirely  governed  by  the  lower  passions 
and  instincts,  whose  higher  moral  sense  has  been  repressed  from  its  earliest  dawn 
by  the  degrading  influence  of  the  conditions  in  which  he  is  placed,  who  has  never 
learned  to  exercise  any  kind  of  self-restraint  (or,  if  he  has  learned  it,  has  only 
been  trained  to  use  it  for  the  lowest  purposes),  who  has  never  heard  of  a  God,  of 

1  Pee  especially  the  work  of  M.  Moreau,  "  Du  Hachisch  et  de  1' Alienation  Mentale,"  of 
which  a  criticnl  analysis  will  be  found  in  the  "Brit,  and  For.  Med.  Rev.,"  vol.  xxiii.  p. 
5J7:  also  the  well-known  "  Confessions  of  an  English  Opium-Eater. " 


CORRELATION   OF    PHYSIOLOGICAL   AND    PYSCHICAL    ACTIONS.       541 

Immortality,  or  of  the  worth  of  his  Soul, — such  a  being,  one  of  those  heathen 
outcas-ts  of  whom  all  our  great  towns  are  unhappily  but  too  productive,  can  surely 
be  no  more  morally  responsible  for  his  actions,  than  the  lunatic  who  has  lost  what- 
ever self-control  he  once  possessed,  and  whose  moral  sense  has  been  altogether 
perverted  by  bodily  disorder.  But  let  the  former  be  subjected  to  the  training  of 
one  of  those  benevolent  individuals  who  know  how  to  find  out  "the  holy  spot  in 
every  child's  heart;"  let  patient  kindness,  continually  appealing  to  the  highest 
motives  which  the  child  can  understand,  progressively  raise  his  moral  standard, 
and  awaken  within  him  the  dormant  susceptibilities  which  enable  him  to  feel 
that  he  has  a  conscience  and  a  duty,  that  there  is  a  Father  who  made  him,  and 
who  watches  over  his  welfare,  that  there  is  a  hereafter  of  rewards  and  punish- 
ments, that  he  has  a  power  within  himself  of  controlling  and  directing  his 
thoughts  and  actions; — then,  and  not  till  then,  in  our  belief,  does  he  become 
truly  responsible  for  his  actions,  either  morally  or  religiously, — then  only  does  he 
rise  from  the  level  of  the  brute,  and  begin  to  show  that  he  is  indeed  made  in  the 
image  of  his  Maker. 

584.  Thus,  then,  we  see  that  the  Materialist  and  the  Spiritualist  doctrines 
alike  recognize,  and  alike  ignore,  certain  great  truths  of  Human  Nature ;  and 
the  question  returns  upon  us,  whether  any  general  expression  can  be  framed, 
which  may  be  in  harmony  alike  with  the  results  of  scientific  inquiry  into 
the  facts  of  the  case,  and  with  those  simple  teachings  of  our  own  conscious- 
ness, which  must,  after  all,  be  recognized  as  affording  the  ultimate  test  of  the 
truth  of  all  Psychological  doctrines.  Such  an  expression  may  be  framed,  as  it 
appears  to  the  Author,  in  strict  accordance  with  true  philosophy,  by  withdrawing 
ourselves  entirely  from  the  futile  attempt  to  bring  Matter  and  Mind  into  the 
same  category,  and  by  fixing  our  attention  exclusively  on  the  relation  between 
Mind  and  Force.  Although  far  from  thinking  that  the  views  here  offered  express 
the  whole  truth,  or  solve  all  the  difficulties  of  the  subject,  he  considers  that  they 
express  so  much  more  than  any  scheme  he  has  ever  heard-of,  that  he  ventures  to 
request  for  them  a  thoughtful  consideratien  on  the  part  of  those  who  feel,  with 
him,  the  importance  of  attaining  some  definite  conceptions  on  this  head. — In  the 
first  place  it  may  be  remarked,  that  the  whole  tendency  of  Philosophical  Investi- 
gation at  the  present  day,  is  to  show  the  utter  futility  of  all  the  controversies  which 
have  been  carried-on  with  regard  to  the  relation  of  Mind  and  Matter.  The 
essential  nature  of  these  two  entities  is  such,  that  no  relation  of  identity  can 
exist  between  them.  Matter  possesses  extension,  or  occupies  space ;  whilst  Mind 
has  no  such  property.  On  the  other  hand,  we  are  cognizant  of  Matter  only 
through  its  occupation  of  space,  of  which  we  are  informed  through  our  senses ; 
we  are  cognizant  of  the  existence  of  Mind  by  our  direct  consciousness  of  feelings 
and  ideas,  which  are  to  us  the  most  certain  of  all  realities.  But,  what  is  perhaps 
a  more  important  distinction,  the  existence  of  Matter  is  essentially  passive ;  left 
to  itself,  it  always  impresses  our  consciousness  in  one  and  the  same  mode;  and 
any  change  in  its  condition  is  the  consequence  of  external  agency.  What  have 
been  termed  the  active  states  of  matter,  are  really  the  manifestations  of  forces,  of 
which  we  can  conceive  as  having  an  existence  independent  of  matter,  and  as 
having  no  other  relation  to  it  than  that  which  consists  in  their  capability  of 
changing  its  state.  Thus  Water  continues  unchanged  so  long  as  its  temperature 
remains  the  same;  but  the  dynamical  agency  of  Heat  occasions  that  mutual 
repulsion  between  its  particles,  which  transforms  it  from  a  non-elastic  liquid  into 
an  elastic  vapour;  and  all  this  heat  is  given-forth  from  it  again,  when  the  aqueous 
vapour  is  transformed  back  to  the  liquid  state.  On  the  other  hand,  the  existence 
of  Mind  is  essentially  active:  all  its  states  are  states  of  change,  and  we  know 
nothing  whatever  of  it  save  by  its  changes-.  Sensation,  Perception,  Idea, 
Emotion,  Reasoning  process,  &c.,  in  fact  every  term  which  expresses  a  Mental 
state,  is  a  designation  of  a  phase  of  mental  existence  that  intervenes  between 
other  phases,  in  the  continual  succession  of  which  our  idea  of  Mind  consists. 


542  FUNCTIONS   OF    THE   CERBBRO-SPINAL   NERVOUS   SYSTEM. 

585.  But  whilst  between  Matter  and  Mind  it  is  utterly  vain  to  attempt  to 
establish  a  relation  of  identity  or  analogy,  a  very  close  relation  may  be  shown  to 
exist  between  Mind  and  Force.     For,  in  the  first  place,  Force,  like  Mind,  can  be 
conceived-of  only  as  in  a  state  of  activity ;  and  our  idea  of  it  essentially  consists 
in  the  succession  of  different  states,  under  which  its  manifestations  present  them- 
selves to  our  conciousness.     But,  secondly,  our  consciousness  of  Force  is  really 
as  direct,  as  is  that  of  our  own  mental  state;1  our  notion  of  it  being  based  upon 
our  internal  sense  of  the  exertion  which  we  determinately  make  to  develope  one 
form  of  Force,  which  may  be  taken  as  the  type  of  all  the  rest, — that,  namely, 
which  produces  or  which  resists  motion.     When  we  attempt  to  lift  a  weight,  or 
to  turn  a  windlass,  or  to  stop  a  horse  that  is  running-away,  we  are  directly  conscious 
of  a  mental  exertion,  as  the  immediate  and  invariable  antecedent  of  the  develop- 
ment of  motor  power  through  the  contraction  of  our  muscles ;  and  the  connec- 
tion of  the  two  is  further  established  by  that  'sense  of  effort'  which  we  intui- 
tively refer  to  the  muscles  themselves,  arising  as  it  does  from  their  own  condition 
(§  545) ;  and  thus  we  are  led  to  feel  that,  in  this  particular  case,  Force  must  be 
regarded  as  the  direct  expression  or  manifestation  of  that  Mental  state  which  we 
call  Will.    The  analogy  becomes  stronger,  when  we  trace  it  into  the  relations  which 
these  two  agencies  respectively  bear  to  Matter.     For  in  the  phenomenon  of  Vol- 
untary movement  we  can  scarcely  avoid  seeing  that  Mind  is  one  of  the  dynamical 
agencies   which    is   capable  of  acting-on    Matter;    and    that,   like    other   such 
agencies,  the  mode  of  its  manifestation  is  affected  by  the  nature  of  the  material 
substratum   through  which   its   influence   is   exerted.     Thus,  the  Physiologist 
knows  full  well,  that  the  immediate  operation  of  the  Will  is  not  upon  the  Muscle 
but  upon  the  Brain,  wherein  it  excites  that  active  state  of  Nervous    matter, 
which  he  designates  as  the  operation  of  Nerve-force ;  and  that  the  propagation  of 
this  force  along  the  Nerve-trunks  is  the  determining  cause  of  the  Muscular  contrac- 
tion, which  is  the  immediate  source  of  the  motor  power.     He  knows,  too,  that  this 
dynamical  metamorphosis  is  effected  (like  every  other  analogous  change)  by  the 
intermediation  of  a  peculiar  material  substratum,  which  itself  undergoes  a  change 
of  condition ;    the  components  both  of  the  Nervous  and  Muscular  substances 
ceasing  to  exist  under  their  previous  forms,  and  entering  into  new  combinations. 
Thus,  then,  we  have  evidence,  in  what  we  know  of  the  physiological  conditions 
under  which  Mind  produces  Motion,  that  certain  forms  of  Vital  Force  constitute 
the  connecting  link  between  the  two ;  and  it  is  difficult  to  see  that  the  dynamical 
agency  which  we  term  Will  is  more  removed  from  Nerve-force,  on  the  one  hand, 
than  Nerve-force  is  removed  from  Motor  force  on  the  other.     Each,  in  giving 
origin  to  the  next,  is  itself  expended,  or  ceases  to  exist  as  such ;  and  each  bears, 
in  its  own  intensity,  a  precise  relation  to  that  of  its  antecedent  and  its  consequent. 

586.  But  we  have  not  only  evidence  of  the  excitement  of  Nerve-force  by 
Mental  agency;  the  converse  is  equally  true,  Mental  activity  being  excited  by 
Nerve-force.     For  this  is  the  case  in  every  act  in  which  our  Consciousness  is 
excited  through  the  instrumentality  of  the  Sensorium,  whether  its  condition  be 
affected  by  impressions  made'  upon  Organ  of  Sense,  or  by  changes  in  the  state 
of  the  Cerebrum  itself;  a  certain  active  condition  of  the  nervous  matter  of  the 
Sensorium,  being  (we  have  every  reason  to  believe)  the  immediate  antecedent  of 
all  consciousness,  whether  sensational   or  ideational.     And  thus  we  are  led  to 
perceive,  that,  as  the  power  of  the  Will  can  develope  Nervous  activity,  and  as 
Nerve-force  can  develope  Mental  activity,  there  must  be  a  Correlation  between 
these  two  modes  of  dynamical  agency,  which  is  not  less  intimate  and  complete 
than  that  which  exists  between  Nerve-force  on  the  one  hand  and  Electricity  or 
Heat  on  the  other.     (PniNC.  OF  GEN.  PHYS.,  Am.  Ed.) 

587.  This  idea  of  Correlation  of  Forces  will  be  found  completely  to  harmonize 
with  those  phenomena  already  referred-to,  which  unmistakeably  indicate  the  in- 

1  This  was  long  since  hinted-at  by  Locke,  in  the  Chapter  'Of  Power'  in  hi*  "  Essay  on 
the  Human  Understanding,"  Book  n.  Chap.  xxi. 


CORRELATION    OF    PHYSIOLOGICAL   AND    PSYCHICAL   ACTION.         543 

nuence  of  physical  conditions  in  the  determination  of  mental  states  (§  580) } 
whilst,  on  the  other  hand,  it  explains  that  relation  between  Emotional  excitement 
and  bodily  change,  which  is  manifested  in  the  subsidence  of  the  former,  when  it 
has  expended  itself  in  the  production  of  the  latter  (§  624).  And  further,  it 
will  be  found  no  less  applicable  to  the  explanation  of  all  that  automatic  action 
of  the  Mind,  which  consists  in  the  succession  of  ideas,  according  to  certain 
'  laws  of  thought/  without  the  exercise  of  any  control  or  direction  on  the  part 
of  the  individual  to  whose  consciousness  they  present  themselves,  and  which 
manifests  itself  in  the  action  of  those  ideas  upon  the  centres  of  movement. 
For  this  succession  must  be  regarded  as  the  exponent  of  a  series  of  changes 
taking  place  in  the  Cerebrum  itself,  in  respondence  to  impressions  made  upon  it  j 
whilst  the  movements  which  proceed  from  these  must  be  considered  as  being  no 
less  the  results  of  its  '  reflex  '  or  ( ideo-motor  '  operation,  than  are  the  l  consen- 
sual '  of  the  reflex  action  of  the  Sensory  Ganglia,  and  the  i  excito-motor '  of  that 
of  the  Spinal  Cord.1  For  all  Physiological  purposes,  then,  we  may  consider  the 
nervous  matter  of  the  Cerebrum  as  the  material  substratum  through  which  the 
metamorphosis  of  Nerve-force  into  Mind-force,  and  of  Mind-force  into  Nerve- 
force,  is  effected;  and  as  every  such  metamorphosis  involves,  like  other  analogous 
transformations,  a  change  in  the  state  of  the  matter  through  which  it  is  effected, 
so  should  we  expect  that  Mental  activity  would  involve  the  disintegration  of  the 
Nervous  substance  which  thus  ministers  to  it;  and  such  appears  from  a  variety 
of  evidence,  to  be  really  the  case.  (See  PRINC.  OF  GEN.  PHYS.,  Am.  Ed.) 

588.  It  is  obvious  that  the  view  here  taken  does  not  in  the  least  militate 
against  the  idea,  that  Mind  may  have  an  existence  altogether  independent  of 
the  Material  body  through  which  it  thus  manifests  itself.  All  which  has  been 
contended  for  is,  that  the  connection  between  the  Mind  and  Body  is  such,  that 
each  has,  in  virtue  of  its  constitution,  a  determinate  relation  to  the  other,  in  this 
present  state  of  existence  (which  is  all  of  which  Science  can  legitimately  take 
cognizance);  and  that  the  actions  of  our  Minds,  in  so  far  as  they  are  carried-on 
without  any  interference  from  our  Will,  may  be  considered  (in  the  limited  sense 
formerly  explained,  §  46,  note)  as  '  functions  of  the  Cerebrum/  —  On  the  other 
hand,  in  the  control  and  direction  which  the  Will  has  the  power  of  exerting  over 
the  course  of  the  thoughts,  we  have  the  evidence  of  a  new  and  independent 
power,  which  is  entirely  opposed  in  its  very  nature  to  all  the  automatic  tendencies, 
and  which,  according  as  it  is  habitually  exerted,  tends  to  render  the  individual  a 
free  agent.  And,  truly,  in  the  existence  of  this  Power,  which  is  capable  of 
dominating  over  the  very  highest  of  those  operations  that  we  know-of  as  connected 
with  corporeal  states,  we  find  a  better  evidence  than  we  gain  from  the  study  of 
any  other  part  of  our  psychical  nature,  that  there  is  an  entity  wherein  Man's 
nobility  essentially  consists,  which  does  not  depend  for  its  existence  on  any 
play  of  psychical  or  vital  forces,  but  which  makes  these  subservient  to  its  deter- 
minations. It  is,  in  fact,  the  virtue  of  the  Will,  that  we  are  not  mere  thinking 
automata,  mere  puppets  to  be  pulled  by  suggesting-strings,  capable  of  being 
played-upon  by  every  one  who  shall  have  made  himself  master  of  our  springs  of 
action.  It  may  be  freely  admitted  that  such  thinking  automata  do  exist :  for 

1  The  application  of  the  doctrine  of  'reflex  action'  to  the  Brain,  was  first  fully  developed 
by  Dr.  Laycock  of  York,  in  a  paper  '  On  the  Reflex  Function  of  the  Brain,'  read  before 
the  Medical  Section  of  the  British  Association  at  its  meeting  in  York,  Sept.,  1844,  and 
afterwards  published  in  the  "Brit,  and  For.  Med.  Rev.,"  vol.  xix. — Not  having  recog- 
nized what  appears  to  the  Author  the  essential  distinction,  both  in  their  anatomical  and 
physiological  relations,  between  the  Sensory  Ganglia  and  the  Cerebral  or  Hemispheric 
Ganglia,  Dr.  Laycock  did  not  mark-out  the  distinction  between  the  '  semori-motor '  or 
'consensual'  actions,  which  are  the  manifestations  of  the  reflex  power  of  the  former,  and 
the  '  ideo-motor '  actions  which  depend  upon  the  reflex  action  of  the  latter.  But  in  adopt- 
ing that  part  of  it  which  is  strictly  applicable  to  the  Cerebrum,  and  in  applying  it  to  those 
various  states  which  agree  in  the  common  characteristic  of  the  existence  of  Mental  Activity 
without  Volitional  control,  the  Author  considers  that  he  is  merely  giving  greater  definite- 
ness  and  a  wider  application  to  Dr.  Laycock's  doctrine. 


544  FUKCTIONS   OF   THE   CEREBRO-SPINAL  NERVOUS   SYSTEM. 

there  are  many  individuals  whose  Will  has  never  been  called  into  due  exercise, 
and  who  gradually  or  almost  entirely  lose  the  power  of  exerting  it,  becoming  the 
mere  creatures  .of  habit  and  impulse;  and  there  are  others  in  whom  (as  we  shall 
hereafter  see)  such  states  are  of  occasional  occurrence;  whilst  in  others,  again, 
they  may  be  artificially  induced.  And  it  is  by  the  study  of  those  states  in  which 
the  Will  is  completely  in  abeyance,  —  the  course  of  thought  being  entirely  deter- 
mined by  the  influence  of  suggestions  upon  the  Mind,  whose  mode  of  reaction 
upon  them  depends  upon  its  original  peculiarities  and  subsequently-acquired 
habits, — and  by  the  comparison  of  such  states  with  that  in  which  an  individual, 
in  full  possession  of  all  hvs  faculties,  and  accustomed  to  the  habitual  control  and 
direction  of  his  thoughts,  determinately  applies  his  judgment  to  the  formation  of 
a  decision  between  various  plans  of  action,  involving  the  appreciation  of  opposing 
motives, — that  we  shall  obtain  the  most  satisfactory  ideas  of  what  share  the  Will 
really  takes  in  the  operations  of  our  minds  and  in  the  direction  of  our  conduct, 
and  of  what  must  be  set  down  to  that  Automatic  operation  of  our  psychical  nature 
which  is  correlated  to  Cerebral  action.1 

589.  This  view,  moreover,  appears  to  the  Author  to  be  capable  of  legitimate 
extension,  from  the  constitution  of  the  Human  mind,  and  its  relation  to  our 
bodily  organism,  to  the  notion  which  we  form  of  the  relation  of  the  Mind  of  the 
Deity  to  that  Universe,  whose  phenomena,  rightly  interpreted,  are  but  a  continual 
revelation  of  His  ceaseless  and  universal  presence.  And  it  seems  desirable  here 
to  advert  to  this  subject  (foreign  though  it  may  seem  to  the  proper  object  of  this 
Treatise),  not  merely  for  the  sake  of  showing  that  the  doctrine  here  propounded 
is  strictly  conformable  to  the  highest  teachings  of  religion,  but  because  it  seems 
to  afford  some  guidance  towards  the  solution  of  difficulties  which  have  perplexed 
many  deep-thinking  men,  and  which  have  especially  tended  to  keep  Science  and 
lleligion  apart  from  one  another,  rendering  the  physical  philosopher  either  an 
avowed  sceptic  or  a  mere  speculative  religionist,  and  inspiring  the  religionist  with 
a  bigotted  horror  of  science. — The  conception  which  each  individual  forms  of 
the  Divine  Nature  (§  616),  depends  in  great  degree  upon  his  own  habits  of 
thought;  but  there  are  two  extremes,  towards  one  or  other  of  which  most  of  thj 
current  notions  on  this  subject  may  be  said  to  tend,  and  between  which  they 
seem  to  have  oscillated  in  all  periods  of  the  history  of  Monotheism.  These  are, 
Pantheism,  and  Anthropomorphism. — Towards  the  Pantheistic  aspect  of  Deity, 
we  are  especially  led  by  the  philosophic  contemplation  of  His  agency  in  external 
Nature;  for  in  proportion  as  we  fix  our  attention  exclusively  upon  the  Maws' 
which  express  the  orderly  sequence  of  its  phenomena,  and  upon  the  ' forces' 
whose  agency  we  recognize  as  their  immediate  causes,  do  we  come  to  think  of 
the  Divine  Being  as  the  mere  First  Principle  of  the  Universe,  as  an  all-compre- 
hensive 'Law'  to  which  all  other  laws  are  subordinate,  as  that  most  general 
f  Cause '  of  which  all  the  physical  forces  are  but  manifestations.  This  conception 
embodies  a  great  truth,  and  a  fundamental  error.  Its  truth  is  the  recognition 
of  the  universal  and  all-controlling  agency  of  the  Deity,  and  of  His  presence  in 
Creation  rather  than  on  the  outside  of  it.  Its  error  lies  in  the  absence  of  any 
distinct  recognition  of  that  conscious  volitional  agency,  which  is  the  essential 
attribute  of  Personality,  for  without  this,  the  Universe  is  nothing  else  than  a 
great  self-acting  machine,  its  laws  are  but  the  expressions  of  l  surd  necessity,'  and 
all  the  higher  tendencies  and  aspirations  of  the  Human  Soul  are  but  a  *  mockery, 
a  delusion,  and  a  snare.' — The  Anthropomorphic  conception  of  Deity,  on  the 
other  hand,  arises  from  the  too  exclusive  contemplation  of  our  own  nature  as  the 

1  The  Author  has  had  the  satisfaction  of  finding  that  Mr.  J.  D.  Morell,  who  has  acquired 
for  himself  a  high  place  among  British  Psychologists,  has  considered  his  views  on  the 
Correlation  between  Mental  and  Nervous  action  to  be  worthy  of  adoption  into  his  recently- 
published  "Elements  of  Psychology;"  in  which  they  are  connected  with  a  very  ingenious 
doctrine  of  the  Soul,  which  Mr.  M.  regards  (with  many  of  the  older  Philosophers)  as 
acting  unconsciously  in  the  development  and  conservation  of  the  Body,  as  well  as  mani- 
festing itself  consciously  in  the  phenomena  of  Mind. 


SENSATIONAL     CONSCIOUSNESS.  545 

type  of  the  Divine ;  and  although  in  the  highest  form  in  which  it  may  be  held, 
it  represents  the  Deity  as  a  being  in  whom  all  the  noblest  attributes  of  Man's 
spiritual  essence  are  expanded  to  infinity,  yet  it  is  practically  limited  and  degraded 
by  the  impossibility  of  fully  realizing  such  an  existence  to  our  minds;  the  fail- 
ing's and  imperfections  incident  to  our  Human  nature  being  attributed  to  tho 
Divine,  in  proportion  as  the  low  standard  of  intellectual  and  moral  development 
in  each  individual  keeps-down  his  idea  of  possible  excellence.  Even  the  lowest 
form  of  any  such  conception,  however,  embodies  (like  the  Pantheistic)  a  great 
truth,  though  mingled  with  a  large  amount  of  error.  It  represents  the  Deity  as 
a  Person;  that  is,  as  possessed  of  that  Intelligent  Volition,  which  we  recognize 
in  ourselves  as  the  source  of  the  power  we  determinately  exert,  through  our 
bodily  organism,  upon  the  world  around  j  and  it  invests  Him  also  with  those 
Mo'ral  attributes,  which  place  him  in  sympathetic  relation  with  his  sentient 
creatures.  But  this  conception  is  erroneous,  in  so  far  as  it  represents  the  Divine 
Nature  as  restrained  in  its  operations  by  any  of  these  limitations  which  are  in- 
herent in  the  very  constitution  of  Man  ;  and  in  particular,  because  it  leads  those 
who  accept  it,  to  think  of  the  Creator  as  "a  remote  and  retired  mechanician, 
inspecting  from  without  the  engine  of  creation  to  see  how  it  performs,"  and  as 
either  leaving  it  entirely  to  itself  when  once  it  has  been  brought  into  full  activity, 
Dr  as  only  interfering  at  intervals  to  change  the  mode  of  its  operation. 

590.  Now  the  truths  which  these  views  separately  contain,  are  in  perfect  har- 
mony with  each  other;  and  the  very  act  of  bringing  them  into  combination, 
effects  the  elimination  of  the  errors  with  which  they  were  previously  associated. 
For  the  idea  of  the  universal  and  all-controlling  agency  of  the  Deity,  and  of  His 
immediate  presence  throughout  Creation,  is  not  found  to  be  in  the  least  degree 
inconsistent  with  the  idea  of  His  personality,  when  that  idea  is  detached  from 
the  limitations  which  cling  to  it  in  the  minds  of  those,  who  have  not  expanded 
their  anthropomorphic  conception  by  the  scientific  contemplation  of  Nature.     On 
the  contrary,  when  we  have  once  arrived  at  that  conception  of  Force  as  an  ex- 
pression of  Will,  which  we  derive  from  our  own  experience  of  its  production,  the 
universal  and  constantly-sustaining  agency  of  the  Deity  is  recognized  in  every 
phenomenon  of  the  external  Universe ;  and  we  are  thus  led  to  feel  that  in  the 
Material  Creation  itself,  we  have  the  same  distinct  evidence  of  His  personal  ex- 
istence and  ceaseless  activity,  as  we  have  of  the  agency  of  intelligent  minds  in 
the  creations  of  artistic  Genius,  or  in  the  elaborate  contrivances  of  Mechanical 
skill,  or  in  those  written  records  of  Thought  which  arouse  our  own  psychical 
nature  into  kindred  activity. 

591.  Of  Sensational  Consciousness. — The  origin  of  all  Mental  activity  lies  in 
affections  of  the  Consciousness,  produced  by  impressions  made  upon  some  part  of 
our  bodily  organism  that  is  supplied  with  afferent  nerves,  and  transmitted  through 
them  to  the  Sensorium ;  and  affections  of  the  consciousness  thus  directly  occa- 
sioned by  impressions  external  to  it,  are  termed  Sensations.* — If  it  were  possible 
for  a  Human  being  to  come  into  the  world,  with  a  Brain  perfectly  prepared  to 
be  the  instrument  of  psychical  operations,  but  with  all  the  inlets  to  sensation 
closed,  we  have  every  reason  to  believe  that  the  Mind  would  remain  dormant, 
like  a  seed  buried  deep  in  the  earth.     The  attentive  study  of  cases  in  which 
there  is  congenital  deficiency  of  one  or  more  sensations,  makes  it  evident  that 
the  Mind  is  utterly  incapable  of  forming  any  definite  ideas  in  regard  to  those 
properties  of  objects,  of  which  those  particular  sensations  are  adapted  to  taku 
cognizance.     Thus  the  man  who  is  born  blind  can  form  no  conception  of  colour ; 
nor  the  congenitally-deaf,  of  musical  tones.     And  in  those  lamentable  cases,  in 
which  the  sense  of  Touch  is  the  only  one  through  which  ideas  can  be  called-fbrth, 

1  Some  Physiologists,  it  is  true,  have  spoken  of  a  sensation  without  consciousness ;  but  it 
seems  very  desirable,  for  the  sake  of  clearness  and  accuracy,  to  limit  the  application  of 
the  word  to  the  mental  change,  especially  since  the  term  'impression'  serves  to  designate 
that  change  in  the  state  of  the  Nervous  system,  which  is"  its  immediate  antecedent. 
35 


546  FUNCTIONS   OF  THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

the  mental  operations  necessarily  remain  of  the  simplest  and  most  limited  cha- 
racter, unless  the  utmost  attention   be  given  by  a  judicious  instructor,  to  the 
development  of  the  intellectual  faculties,  and  the  cultivation  of  the  moral  feelings, 
through  that  restricted  class  of  ideas  which  there  is  a  possibility  of  exciting.' — 
The  activity  of  the  Mind,  then,  is  just  as  much  the  result  of  it  consciousness  of 
external  impressions,  by  which  its  faculties  are  called  into  play,  as  the  Life  of  the 
body  is  dependent  upon  the  appropriation  of  nutrient  materials,  and  the  constant 
influence  of  external  forces.     But  there  is  this  difference  between  the  two  cases, — 
that  whilst  the  Body  continually  requires  new  materials  and  a  continued  action 
of  external  agencies,  the  Mind,  when  it  has  been  once  called  into  activity,  and 
has  become  stored  with  ideas,  may  remain  active,  and  may  develope  new  relations 
and  combinations  amongst  these,  after  the  complete  closure  of  the  sensorial  inlets 
by  which  new  ideas  can  be  excited  ab  externo.     Such,  in  fact,  is  what  is  continu- 
ally going-on  in  the  state  of  Dreaming;  but  examples  yet  more  remarkable  are 
furnished  in  the  vivid  conceptions  which  may  be  formed  of  a  landscape  or  a  pic- 
ture, from  oral  description,  by  those  who  have  once  enjoyed  sight;  or  in  the 
composition  of  music,  even  such  as  involves  new  combinations  of  sounds,  by  those 
who  have  become  deaf,  as  in  the  well-known  case  of  Beethoven.     The  mind  thus 
feeds,  as  it  were,  upon  the  store  of  ideas  which  it  has  laid-up  during  the  activity 
of  its  sensory  organs ;  and  not>  only  are  those  impressions  which  it  consciously 
retains,  worked-up  into  a  never-ending  variety  of  combinations  and  successions 
of  ideas,  thus  continuing  to  afford  new  sources  of  mental  activity  even  to  the  very 
end  of  life ;  but  those  impressions  of  which  the  mind,  though  once  conscious  of 
them,  seems  even  to  itself  to  have  entirely  lost  the  traces,  may  recur  spontane- 
ously and  influence  its  trains  of  thought,  at  periods  long  subsequent  to  their 
reception.     Hence  we  seem  justified  in  affirming   that  some  change  must  be 
effected  in  the  condition  of  the  Nervous  Centres,  by  every  impression   of  which 
we  become  conscious,  whereby  that  impression  is  organically  perpetuated,  in  such 
a  manner  as  to  allow  of  its  presenting  itself  anew  to  the  cognizance  of  the  mind 
at  any  future  time  when  it  may  be  excited  from  a  passive  to  an  active  condition. 
Examples  of  this  kind  are  occasionally  furnished  in  the  delirium  of  fever  orphre- 
nitis ;  for  though  it  commonly  happens  that  ideas  are  thus  recalled,  in  the  first 
instance,  rather  than  sensations,  yet  there  are  some  very  striking  cases,  in  which 
the  sensations  have  been  of  such  a  kind  that  no  definite  idea  could  well  have 
been  attached  to  them  by  the  individual.     A  very  extraordinary  case  of  this  kind 
has  been  recorded,2  in  which  a  woman,  during  the  delirium  of  fever,  continually 
repeated  sentences  in  languages  unknown  to  those  around  her,  which  were  found 
to  be  Latin,  Greek,  and  Hebrew,  chiefly  of  the  Rabbinical  dialect.     Of  these 
she  stated  herself,  on  her  recovery,  to  be  perfectly  ignorant;  but  on  tracing  her 
former  history,  it  was  ascertained  that,  in  early  life  she  had  lived  as  servant  with 
a  clergyman,  who  had  been  accustomed  to  walk  up  and  down  his  passage,  repeat- 
ing or  reading  aloud  sentences  in  these  languages,  which  she  must  have  retained 
in  her  memory  unconsciously  to  herself. — Of  the  nature  of  the  change  by  which, 
sensory  impressions  are  thus  registered,  it  seems  in  vain  to  speculate ;  there  can 
be  little  question,  however,  that  it  is  in  some  way  dependent  upon  the  nutrition 
of  the  Encephalon,  since  we  see  that  alterations  in  that  function  have  a  marked 
effect  upon  the  Memory.     Thus,  in  the  case  just  cited,  we  can  scarcely  doubt 
that  some  alteration  either  in  the  circulation  of  the  blood,  or  in  the  quality  of 
the  fluid,  was  the  cause  of  changes,  which,  operating  in  the  substance  of  the 
Sensorium,  reproduced  the  former  sensations ;  just  as  a  disturbance  of  the  circu- 
lation in  the  retina  occasions  the  sensation  of  flashes  of  light  or  other  visual 
phenomena  (§  597). 

592.  The  acuteness  with  which  particular  Sensations  are  felt,  is  influenced  in 

1  Of  the  extent  to  -which  this  may  be  accomplished,  the  well-known  case  of  Laura  Bridge- 
roan  affords  a  most  remarkable  exemplification. 

'  Coleridge's  "  Biographia  Literaria,"  vol.  i.  p.  112. 


SENSATIONAL    CONSCIOUSNESS.  547 

a  remarkable  degree  by  the  Attention  they  receive  from  the  mind.  If  the  mind 
be  entirely  inactive,  as  in  profound  sleep,  no  sensation  whatever  is  produced  by 
ordinary  impressions  ;  and  the  same  is  the  case  when  the  attention  is  so  completely 
concentrated  upon  some  object  of  thought  or  contemplation,  that  impressions 
altogether  unconnected  with  it  fail  to  make  any  impression  on  the  sensational  con- 
sciousness. On  the  other  hand,  when  the  attention  is  from  any  cause  strongly 
directed  towards  them,  impressions  that  are  very  feeble  in  themselves,  produce 
sensations  of  even  painful  acuteness  ;  thus  every  one  knows  how  much  a  slight 
itching  of  some  part  of  the  surface  may  be  magnified  by  the  direction  of  the 
thoughts  to  it,  whilst,  as  soon  as  they  are  forced  by  some  stronger  impression 
into  another  channel,  the  irritation  is  no  longer  felt ;  so,  too,  it  must  be  within 
the  experience  of  most  persons,  how  vividly  sounds  are  perceived  when  they 
break-in  upon  the  stillness  of  the  night,  being  increased  in  strength,  not  only  by 
the  contrast,  but  by  absorbing  the  whole  attention.  An  interesting  experiment 
is  mentioned  by  Miiller,  which  shows  how  completely  the  mind  may  be  uncon- 
scious of  impressions  communicated  to  it  by  one  organ  of  sense,  when  occupied, 
even  without  a  distinct  effort  of  the  will,  by  those  received  through  another.  If 
we  look  at  a  sheet  of  white  paper  through  two  differently-coloured  glasses  at  the 
same  time  (one  being  placed  before  each  eje),  the  resulting  sensation  is  seldom 
that  of  a  mixture  of  the  colours  :  if  the  experiment  be  tried  with  blue  and  yellow 
glasses,  for  example,  we  do  not  see  the  paper  of  an  uniform  green  ;  but  the  blue 
is  predominant  at  one  moment,  and  the  yellow  at  another ;  or  blue  nebulous 
spots  may  present  themselves  on  a  yellow  field,  or  yellow  spots  on  a  blue  field. 
We  perceive  from  this  experiment,  that  the  Attention  may  not  only  be  directed 
to  the  impressions  made  on  either  retina,  to  the  complete  exclusion  of  those  of 
the  other,  but  it  may  be  directed  to  those  made  on  particular  spots  of  either. 
This  may  be  noticed,  again,  in  the  process  by  which  we  make  ourselves  acquainted 
with  a  landscape  or  a  picture ;  if  our  Attention  be  directed  to  the  whole  field  of 
vision  at  once,  we  see  nothing  distinctly;  and  it  is  only  by  abstracting  ourselves 
from  the  contemplation  of  the  greater  part  of  it,  and  by  directing  our  attention  to 
smaller  portions  in  succession,  that  we  can  obtain  a  definite  conception  of  the  de- 
tails. The  same  is  the  case  in  regard  to  auditory  impressions;  and  here  the 
power  of  Attention,  in  causing  one  sensation  or  series  of  sensations  to  predomi- 
Late  over  others  which  are  really  more  intense,  is  often  most  remarkably  mani- 
fested. When  we  are  listening  to  a  piece  of  music  played  by  a  large  orchestra, 
for  example,  we  may  either  attend  to  the  combined  effect  of  all  the  instruments, 
or  we  may  single-out  any  one  part  in  the  harmony,  and  follow  this  through  all  its 
mazes ;  and  a  person  with  a  practised  ear  (as  it  is  commonly  but  erroneously 
termed,  it  being  not  the  ear  but  the  mind  that  is  practised,)  can  even  distin- 
guish the  sound  of  the  weakest  instrument  in  the  whole  band,  and  can  follow 
its  strain  through  the  entire  performance.  This  attention  to  a  single  element 
can  only  be  given,  however,  by  withdrawing  the  mind  from  the  perception  of  the 
remainder;  and  a  musician  who  thus  listens,  will  have  very  little  idea  of  the  rest 
of  the  harmonic  parts,  or  of  the  general  effect.  In  fact,  when  the  mind  is  thus 
directed,  by  a  strong  effort  of  the  Will,  into  a  particular  channel,  it  may  be  almost 
considered  as  unconscious  quoad  any  other  impressions;  and  in  those  curious 
states  (§§  672,  694)  in  which  it  can  be  entirely  governed  by  external  suggestion, 
its  attention  may  be  so  completely  concentrated  upon  some  other  objects,  thafc 
even  the  most  painful  impressions  do  not  affect  the  consciousness. 

593.  The  effects  of  Attention  are  manifested,  not  only  in  regard  to  the  sensa- 
tions which  are  excited  by  external  impressions,  but  also  in  respect  to  those 
which  originate  within  the  system.  Every  one  is  aware  how  difficult  it  is  to 
keep  the  body  perfectly  quiescent,1  especially  when  there  is  a  particular  motive 
for  doing  so,  and  when  the  attention  is  strongly  directed  to  the  object.  This  is 
experienced  even  whilst  a  photogenic  likeness  is  being  taken,  when  the  position 

1  Of  course  the  movements  of  respiration  and  winking  are  left  out  of  the  question. 


548  FUNCTIONS   OF   THE  CEREBRO-SPINAL  NERVOUS   SYSTEM. 

is  chosen  by  the  individual,  and  a  support  is  adapted  to  assist  him  in  retaining 
it ;  and  it  is  still  more  strongly  felt  by  the  performers  in  the  '  tableaux  vivans,' 
who  cannot  keep  up  the  effort  for  more  than  three  or  four  minutes.  Now  it  is 
well  known  that,  when  the  attention  is  strongly  directed  to  an  entirely  different 
object  (when  we  are  listening,  for  example,  to  an  eloquent  sermon  or  an  interest- 
ing 1-ecture),  the  body  may  remain  perfectly  motionless  for  a  much  longer  period  ; 
the  uneasy  sensations,  which  would  otherwise  have  induced  the  individual  to 
change  his  position,  not  being  perceived  :  but  no  sooner  is  the  discourse  ended, 
than  a  simultaneous  movement  of  the  whole  audience  takes  place,  every  one  then 
becoming  conscious  of  some  discomfort,  which  he  seeks  to  relieve.  This  is  the 
case  also  in  regard  to  the  respiratory  sensation ;  for  it  may  generally  be  observed 
that  the  usual  reflex  movements  do  not  suffice  for  the  perfect  aeration  of  the 
blood,  and  that  a  more  prolonged  inspiration,  prompted  by  an  uneasy  feeling, 
takes  place  at  intervals ;  but  under  such  circumstances  as  those  just  alluded-to, 
this  feeling  is  not  experienced  until  the  attention  ceases  to  be  engaged  by  a  more 
powerful  stimulus,  and  then  it  manifests  itself  by  the  deep  inspirations,  which 
accompany,  in  almost  every  individual,  the  general  movement  of  the  body. 

594.  It  is  a  general  rule,  with  regard  to  all  sensations,  that  their  intensity  ia 
much  affected  by  Habit ;  being  greatly  diminished  by  frequent  and  continual 
repetition.  This  is  not  the  case,  however,  with  regard  to  those  sensations  to 
which  the  attention  is  peculiarly  directed ;  for  these  lose  none  of  their  acute- 
ness  by  frequent  repetition :  on  the  contrary,  they  become  much  more  readily 
cognizable  by  the  mind  (§  738).  We  have  a  good  example  of  both  facts,  in  the 
effects  of  sounds  upon  sleeping  persons  (§§  686,  687).  The  general  law,  then, 
seems  to  be,  that  Sensations,  not  attended  to,  are  blunted  by  frequent  repetition; 
and  this  may  perhaps  be  connected  with,  certain  other  general  facts,  which  lie 
under  the  observation  of  every  oiie. — It  is  well  known  that  the  vividness  of  sen- 
sations depends  rather  on  the  degree  of  change  which  they  produce  in  the  sys- 
tem, than  on  the  absolute  amount  of  the  impressing  force;  and  this  is  the  case 
with  regard  alike  to  the  special  and  to  the  ordinary  sensations.  Thus,  our  sensa- 
tions of  heat  and  cold  are  entirely  governed  by  the  previous  condition  of  the  parts 
affected ;  as  is  shown  by  the  well-known  experiment  of  putting  one  hand  into  hot 
water,  the  other  into  cold,  and  then  transferring  both  into  tepid  water,  which 
will  seem  cool  to  one  hand,  and  warm  to  the  other.  Every  one  knows,  too,  how 
much  more  we  are  affected  by  a  warm  day  at  the  commencement  of  summer, 
than  by  an  equally  hot  day  later  it,  the  season.  The  same  is  the  case  in  regard 
to  light  and  sound,  smell  and  taste.  A  person  going  out  of  a  totally  dark  room 
into  one  moderately  bright/  is  for  the  time  painfully  impressed  by  the  light,  but 
soon  becomes  habituated  to  it ;  whilst  another,  who  enters  it  from  a  room  bril- 
liantly illuminated,  will  consider  it  dark  and  gloomy.  Those  who  are  constantly 
exposed  to  very  loud  noises,  become  almost  unconscious  of  them,  and  are  even 
undisturbed  by  them  in  illness ;  and  the  medical  student  well  knows,  that  even 
the  effluvia  of  the  dissecting-room  are  not  perceived,  when  the  organ  of  smell  is 
habituated  to  them  ;  although  an  intermission  of  sufficient  length  would,  in  either 
instance,  occasion  a  renewal  of  the  first  unpleasant  feelings,  when  the  individual 
is  again  subjected  to  the  impression. — Thus  there  seems  reason  to  believe  that 
eensorial  changes  of  frequent  occurrence,  produce  a  modification  in  the  nutrition 
of  the  Sensorium  itself,  which  grows-to  them,  as  it  were,  just  as  other  Nervous 
Centres  may  be  considered  as  growing-to  the  mode  in  which  they  are  habitually 
exercised  (§  515);  for  not  only  would  the  production  of  such  a  modification  be 
quite  in  accordance  with  the  general  phenomena  of  Nutrition,1  but  we  can  scarcely 

1  We  have  a  remarkable  exemplication  of  this,  in  the  tolerance  which  may  be  gradually 
established  in  the  system  for  various  toxic  agents,  especially  for  such  as  particularly 
ari'ect  the  Nervous  substance,  such  as  Opium  or  Alcohol.  It  seems  impossible  to  explain 
this  tolerance  on  any  other  hypothesis,  than  that  of  the  alteration  of  the  nutrition  of  the 
tissue  by  repeated  doses,  so  that  no  further  change  can  be  produced  by  the  quantity  origi- 
nally taken. 


OF    SENSATIONAL    CONSCIOUSNESS.  540 

otherwise  explain  the  progressive  formation  of  that  connection  between  sensorial 
changes  and  motor  actions,  which  gives  rise  to  the  '  secondarily  automatic '  move- 
ments (§  540). — Hence  it  seems  reasonable  to  attribute  that  diminution  in  the 
force  of  Sensations  which  is  the  consequence  of  their  habitual  recurrence,  to  the 
want  of  such  a  change  in  the  condition  of  the  Sensorium  as  is  needful  to  produce 
an  impression  on  the  consciousness,  the  effects  which  they  at  first  induced  being 
no  longer  experienced  in  the  same  degree,  when  the  structure  of  the  part  has 
accommodated  itself  to  them. 

595.  Feelings  of  Pain  or  Pleasure  are  connected  with  particular  sensations, 
which  cannot  (for  the  most  part  at  least)  be  explained  upon  any  other  principle, 
than  that  of  the  necessary  association  of  these  feelings,  by  an  original  law  of  our 
nature,  with  the  sensations  in  question.     As  a  general  rule,  it  may  be  stated,  that 
the  violent  excitement  of  any  sensation  is  disagreeable,  even  when  the  same  sen- 
sation in  a  moderate  degree  may  be  a  source  of  extreme  pleasure.     This  is  the 
case  alike  with  those  impressions,  which  are  communicated  through  the  organs 
of  sight,  hearing,  smell,  and  taste,  as  with  those  that  are  received  through  th* 
nerves  of  common  sensation ;  and  there  can  be  no  doubt  that  the  final  cause,  or 
purpose,  of  the  association  of  painful  feelings  with  such  violent  excitement,  is  to 
stimulate  the  individual  to  remove  himself  from  what  Would  be  injurious  in  its 
effects  upon  the  system.     Thus,  the  pain  resulting  from  violent  pressure  on  the 
cutaneous  surface,  or  from  the  proximity  of  a  heated  body,  gives  warning  of  the 
danger  of  injury,  and  excites  mental  operations  destined  to  remove  the  part  from 
the  influence  of  the  injurious  cause :  and  this  is  shown  by  the  fact,  that  loss  of 
sensibility  is  frequently  the  indirect  occasion  of  severe  lesions, — the  individual 
not  receiving  the  customary  intimation  that  an  injurious  process  is  taking-place.1 
Instances  have  occurred,  in  which  violent  inflammation  of  the  membrane  lining 
the  air-passages,  has  resulted  from  the  eflFects  of  ammoniacal  vapours  introduced 
into  them  during  a  state  of  syncope, — the  patient  not  receiving  that  notice  of  the 
irritation,  which,  in  an  active  condition  of  his  nervous  system,  would  have  pre- 
vented him  from  inhaling  the  noxious  agent. 

596.  The  feelings  of  Pain  or  Pleasure,  which  unaccustomed  sensations  excite, 
are  often  exchanged  for  each  other,  when  the  system  is  habituated  to  them  \  this 
is  especially  the  case  in  regard  to  impressions  communicated  through  the  organs 
of  Smell  arid  Taste.     There  are  many  articles  in  common  use  among  mankind, — 
such  as  tobacco,  fermented  liquors,  &c.,  the  use  of  which  cannot  be  said  to  pro- 
duce a  natural  enjoyment,  since  they  are  at  first  unpleasant  to  most  persons;  and 
yet  they  first  become  tolerable,  then  agreeable ;  and  at  last  the  want  of  them  is 
felt  as  a  painful  privation,  and  the  stimulus  must  be  applied  in  an  increasing 
degree  in  order  to  produce  the  usual  effect. 

597.  It  is  through  the  medium  of  Sensation,  that  we  acquire  a  knowledge  of 

1  The  following  case,  recorded  in  the  "  Journal  of  a  Naturalist,"  affords  a  remarkable 
instance  of  this  general  fact.  The  correctness  of  the  statement  having  been  called  in 
question,  it  was  fully  confirmed  by  Mr.  Richard  Smith,  the  late  senior  Surgeon  of  the 
Bristol  Infirmary,  under  whose  care  the  sufferer  had  been.  "  A  travelling  man,  one  win- 
ter's evening,  laid  himself  down  upon  the  platform  of  a  lime-kiln,  placing  his  feet,  proba- 
bly numbed  with  cold,  upon  the  heap  of  stones,  newly  put  on  to  burn  through  the  night. 
Sleep  overcame  him  in  this  situation ;  the  fire  gradually  rising  and  .increasing,  until  it 
ignited  the  stones  upon  which  his  feet  were  placed.  Lulled  by  the  warmth,  the  man  slept 
on ;  the  fire  increased  until  it  burned  one  foot  (which  probably  was  extended  over  a  vent- 
hole)  and  part  of  the  leg  above  the  ankle  entirely  off,  consuming  that  part  so  effectually, 
that  a  cinder-like  fragment  was  alone  remaining, — and  still  the  wretch  slept  on !  and  iu 
this  state  was  found  by  the  kiln-man  in  the  morning.  Insensible  to  any  pain,  and  igno- 
rant of  his  misfortune,  he  attempted  to  rise  and  pursue  his  journey,  but  missing  his  shoe, 
requested  to  have  it  found ;  and  when  he  was  raised,  putting  his  burnt  limb  to  the  ground 
to  support  his  body,  the  extremity  of  his  leg-bone,  the  tibia,  crumbled  into  fragments, 
having  been  calcined  into  lime.  Still  he  expressed  no  sense  of  pain,  and  probably  experi- 
enced none ;  from  the  gradual  operation  of  the  fire,  and  his  own  torpidity  during  the  hours 
his  foot  was  consuming.  This  poor  drover  survived  his  misfortunes  in  the  hospital  about 
a  fortnight ;  but  the  fire  having  extended  to  other  parts  of  his  body,  recovery  was  hopeless 


550  FU!s7CTIONS    OF   THE   CEREBROSPINAL   NERVOUS    SYSTEM. 

the  material  world  around  us,  by  the  psychica.  operations  which  its  changes  ex- 
cite in  ourselves.     The  various  kinds  or  modes  of  Sensation  excite  in  us  various 
ideas  regarding  the  properties  of  matter;  and  these  properties  are  known  to  us, 
only  through  the  changes  which  they  produce  in  the  several  organs  that  consti- 
tute the  Sensorium  (§  591).     But  with  regard  to  all  kinds  of  Sensation  it  is  to 
be  remembered,  that  as  the  change  of  which  the  Mind  is  informed,  is  not  the 
change  at  the  peripheral  extremities  of  the  nerves,  but  the  change  communicated 
to  the  Sensorium,  it  hence  results,  that  external  agencies  can  give  rise  to  no  kind 
of  sensation,  which  may  not  also  be  produced  by  internal  causes  exciting  changes 
in  the  condition  of  the  nerves  in  their  course,  or  in  the  Sensorium  itself.     This 
very  frequently  happens  in  regard  to  the  senses  of  sight  and  hearing;  flashes  of 
light  being  seen,  and  ringing  sounds  in  the  ears  being  heard,  when  no  external 
stimulus  has  produced  such  impressions.     The  production  of  odorous  and  gusta- 
tive  sensations  from  internal  causes,  is  perhaps  less  common ;  but  the  sense  of 
nausea  is  more  frequently  excited  in  this  manner,  than  by  the  direct  contact  of  a 
nauseating  substance  with  the  tongue  or  fauces.     The  various  phases  of  common 
sensibility  often  originate   thus;    and  the  sense   of   temperature  is  frequently 
affected  without  any  corresponding  affection  of  the  tactile  sensations,  a  person 
being  sensible  of  heat  or  of  chilliness  in  some  part  of  his  body,  without  any  real 
alteration  of  its  temperature.     The  most  common  of  the  internal  causes  of  these 
subjective  sensations  (as  they  have  been  termed,  in  contradistinction  to  the  objec- 
tive, which  result  from  a  real  material  object),  is  congestion  or  inflammation ;  and 
it  is  interesting  to  remark  that  this  cause,  operating  through  each  nerve,  produces 
in  the  sensorium  the  changes  to  which  that  nerve  usually  ministers.     Thus,  con- 
gestion in  the  nerves  of  common  sensation  gives  rise  to  feelings  of  pain  or  unea- 
siness; but  when  occurring  in  the  retina  or  optic  nerve,  it  produces  flashes  of 
light;  and  in  the  auditory  nerve,  it  occasions  'a  noise  in  the  ears.' — But  further, 
the  phenomena  of  subjective  sensation  often  originate  in  peculiar  conditions  of  the 
Encephalon  itself,  and  not  in  the  organs  of  sense  or  the  nervous  trunks ;  thus, 
in  Dreaming,  we  frequently  have  very  vivid  pictures  of  external  objects  presented 
to  our  minds ;  and  we  sometimes  distinctly  hear  voices  and  musical  tones,  or  have 
perceptions  (though  this  is  less  common)  of  tastes  and  odours.     The  phenomena 
of  Spectral  Illusions  are  very  nearly  connected  with  those  of  dreaming  ;  both  may 
be  in  some  degree  influenced  by  external  causes,  acting  upon  the  organs  of  sen- 
sation, which  are  misinterpreted  (as  it  were)  by  the  mind,  owing  to  its  state  of 
imperfect  operation ;  but  both  also  may  entirely  originate  in  the  central  organs. 
There  seems  to  be  no  difference,  in  the  feelings  of  the  individual,  between  the 
sensations  thus  originating,  and  those  which  are  produced  in  the  usual  manner; 
for  we  find  that,  unless  convinced  to  the  contrary  by  their  reason,  persons  who 
witness  spectral  illusions  believe  as  firmly  in  the  reality  of  the  objects  that  come 
before  their  minds,  as  if  the  images  of  those  objects  were  actually  formed  on  their 
retinae.     This  is  another  proof,  if  any  were  wanting,  that  the  organ  of  sense,  with 
the  nerve  belonging  to  it,  is  but  the  instrument  by  which  certain  changes  are 
produced  in  the  Sensorium ;  by  which  changes,  and  not  by  the  immediate  impres- 
sions of  the  objects,  our  Consciousness  is  really  affected. 

598.  There  ia  yet  another  mode,  however,  in  which  Subjective  sensations  may 
be  excited;  namely  by  sensations  originating  in  objective  impressions  on  other 
parts.  Thus  the  irritation  of  a  calculus  in  the  bladder  gives-rise  to  pain  at  the 
end  of  the  penis ;  disease  of  the  hip-joint  is  often  first  indicated  by  pain  in  the 
knee;  irritation  of  the  ovary  will  cause  pain  under  the  mamma;  various  dis- 
orders of  the  liver  occasion  pain  under  the  left  scapula ;  attention  is  often  drawn 
to  diseases  of  the  heart  by  shooting  pains  along  the  arms;  stimulation  of  the 
nipple,  whether  in  the  male  or  female,  gives-rise  to  peculiar  sensations  referred  to 
the  genital  organs;  the  sudden  introduction  of  ice  into  the  stomach  will  cause 
intense  pain  in  the  supra-orbital  region,  and  the  same  pain  is  frequently  occa- 
sioned by  the  presence  of  acid  in  the  stomach,  and  may  be  very  quickly  relieved 


OF    SENSATIONAL    CONSCIOUSNESS.  551 

by  its  neutralization  with  an  alkali.  It  will  be  seen  that  in  most  of  thos-  e-ises, 
r  is  impossible  to  refer  the  sensations  to  any  direct  nervous  connection  with  the 
parts  on  which  the  impressions  are  made;  and  they  can  scarcely  be  otherwise  ac- 
euuuted-for,  than  by  supposing  that  these  impressions  produce  sensorial  changes, 
which  are  referred  to  other  parts,  in  virtue  of  some  central  track  of  communica- 
tion with  them,  analogous  to  that  through  which  reflex  movements  are  excited. 
There  are  circumstances,  indeed,  which  seem  to  render  it  not  improbable,  that 
just  as  the  impression  brought  by  the  afferent  nerves  to  the  central  organs, 
excites  a  reflex  movement  by  disturbing  the  polarity  of  a  motor  nerve,  it  may 
excite  a  <  reflex  sensation '  by  disturbing  the  polarity  of  a  sensory  nerve.  Cer- 
tain it  is  that,  after  the  long  continuance  of  some  of  these  reflex  sensations,  the 
organs  to  which  they  are  referred  themselves  become  diseased,  although  previously 
quite  healthy;  thus,  pain  in  the  testicles  is  frequently  induced  by  irritation 
having  its  seat  in  the  lower  part  of  the  spine,  on  which  if  it  continue,  some 
morbid  affection  of  the  testicle  itself  is  likely  to  supervene;  and  Sir  B.  Brodie- 
has  recorded  several  cases,  in  which  '  nervous '  pains  in  various  parts,  apparently 
of  a  purely  subjective  character,  have  been  followed  by  pain  and  swelling  of  the 
integuments.  These  phenomena  are  perhaps  due  to  that  habitual  direction  of 
the  consciousness  to  the  part,  which  is  prompted  by  the  habitual  sensatjon ;  this 
condition,  as  we  shall  see  hereafter  (CHAP.  XV.),  being  itself  adequate  to  the 
production  of  changes  in  its  ordinary  nutritive  action. 

599.  It  seems  to  be  by  an  innate  law  of  our  constitution,  that  these  subjective 
sensations,  whether  originating  at  the  central  terminations  of  nerves,  or  in  the 
course  of  their  trunks,  should  be  referred  by  the  mind  to  the  ordinary  situations 
of  their  peripheral  extremities  (§  474  i) ;  even  though  these  should  not  exist,  or 
should  be  destitute  of  the  power  of  receiving  impressions.  Thus  after  amputa- 
tions, the  patients  are  for  some  time  affected  with  sensations  (probably  excited  by 
irritation  at  the  cut  ends  of  the  nerves),  which  they  refer  to  the  removed  ex- 
tremities; the  same  has  been  noticed  in  regard  to  the  eye,  as  well  when  it  has 
been  completely  extirpated,  as  when  its  powers  have  been  destroyed  by  disease. 
The  effects  of  the  Taliacotian  operation  afford  a  curiously-illustrative  example  of 
this  principle;  for  until  the  flap  of  skin  from  which  the  nose  is  formed,  obtains 
vascular  and  nervous  connections  in  its  new  situation,  the  sensation  produced  by 
touching  it  is  referred  to  the  forehead.  Another  interesting  illustration  of  it 
may  be  obtained  by  the  following  very  simple  experiment : — if  the  middle  finger 
of  either  hand  be  crossed  behind  the  fore-finger,  so  that  its  extremity  is  on  the 
radial  side  of  the  latter,  and  the  ends  of  the  two  fingers  thus  disposed  be  rolled 
over  a  marble,  pea,  or  other  round  body,  a  sensation  will  be  produced,  which,  if 
uncorrected  by  reason,  would  cause  the  mind  to  believe  in  the  existence  of  two 
distinct  bodies ;  this  is  due  to  the  impression  being  made  at  the  same  time  upon 
the  radial  side  of  the  fore-finger,  and  the  ulnar  side  of  the  middle  finger,  —  two 
spots  which,  in  the  natural  position,  are  at  a  considerable  distance.  —  Sensations 
of  a  purely  Subjective  nature  may  excite  precisely  the  same  muscular  movements, 
or  other  changes  in  the  bodily  system,  as  do  similar  sensations  produced  by  ob- 
jective realities.  Of  this  we  have  abundant  evidence  in  the  effects  of  sensations 
called-up  by  ideas  (§§  549,  602);  the  following  example,  however,  is  peculiarly 
valuable,  as  showing  that  the  sensation  still  operates  in  directing  movement,  even 
though  there  be  an  intellectual  consciousness  that  there  is  no  objective  cause  for 
it,  and  that  the  movement  is  consequently  inappropriate.  A  lady  nearly  con- 
nected with  the  Author,  having  been  frightened  in  childhood  by  a  black  cat, 
which  sprang-up  from  beneath  her  pillow  just  as  she  was  laying  her  bead  upon  it, 
was  accustomed  for  many  years  afterwards,  whenever  she  was  at  all  indisposed,  to 
see  a  black  cat  on  the  ground  before  her;  and  although  perfectly  aware  of  the 
spectral  character  of  the  appearance,  yet  she  could  never  avoid  lifting  her  foot  aa 
if  to  step  over  the  cat,  when  it  seemed  to  be  lying  in  her  path. 
*  "  On  Local  Nervous  Affections,"  1837. 


FUNCTIONS    OP   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

600.  It  is  remarkable  that  not  merely  are  Subjective  sensations,  like  all  others, 
rendered  more  intense  by  the  direction  of  the  attention  to  them,  but  they  may 
be  actually  called  into  existence  by  the  fixation  of  the  attention  on  certain  parts 
of  the  body;  and,  with  yet  greater  force,  by  the  belief  in  the  existence  of  ob- 
jective causes  for  such  sensations.     The  l  effects  of  mental  attention  on  bodily 
organs'  have  been  specially  pointed-out  by  Sir  H.  Holland;1  from  whose  exam- 
ples the  following  may  be  cited  in  proof  of  the  foregoing  position.     "The  atten- 
tion concentrated,  for  so  by  an  effort  of  will  it  may  be,  on  the  head  or  sensorium, 
gives  certain  feelings  of  tension  and  uneasiness,  caused  possibly  by  some  change 
in  the  circulation  of  the  part ;  though  it  may  be  an  effect,  however  difficult  to  be 
conceived,  on  the  nervous  system  itself.     Persistence  in  this  effort,   which  is 
seldom  indeed  possible  beyond  a  short  time  without  confusion,  produces  results 
of  much  more  complex  nature,  and  scarcely  to  be  defined  by  any  common  terms 
of  language."     "  Stimulated  attention  will  frequently  give  a  local  sense  of  arte- 
rial pulsation  where  not  frequently  felt,  and  create  or  augment  those  singing 
noises  in  the  ears,  which  probably  depend  on  the  circulation  through  the  capil- 
lary vessels."     A  similar  direction  of  consciousness  to  the  region  of  the  stomach, 
"creates  in  this  part  a  sense  of  weight,  oppression,  or  other  less  definite  uneasi- 
ness; and,  when  the  stomach  is  full,  appears  greatly  to  disturb  the  due  digestion 
of  the  food.     The  state  and  action  of  the  bowels  are  much  influenced  by  the 
same  cause."     A  peculiar  sense  of  weight  and  restlessness  approaching  to  cramp, 
is  felt  in  a  limb,  to  which  the  attention  is  particularly  directed.     So,  again,  if 
the  attention  be  steadily  directed  to  almost,  any  part  of  the  surface  of  the  body, 
some  feeling  of  itching,  creeping,  or  tickling  will  soon  be  experienced.  —  The 
fact  that  sensations  may  be  modified  by  previous  beliefs,  which  must  be  within 
the  experience  of  every  one,  is  remarkably  illustrated  by  the  well-known  excla- 
mation of  Dr.  Pearson,  "Bless  me,  how  heavy  it  is,"  when  he  first  poised  upon 
his  finger  the  globule  of  potassium  produced  by  the  battery  of  Davy ;  his  pre- 
conception of  the  coincidence  between  metallic  lustre  and  high  specific  gravity, 
causing  him  to  feel  that  as  ponderous,  which  the  unerring  test  of  the  balance 
determined  to  be  lighter  than  water. 

601.  Of  the  absolute  production  of  Subjective  sensations  by  the  conviction  of 
the  existence  of  their  objective  causes,  the  two  following  cases,  related  by  Prof. 
Bennett,2  are  very  satisfactory  examples ;  the  effect  of  the  idea  not  being  limited 
to  the  production  of  the  sensations,  but  extending  itself  to  the  consequences  which 
would  have  followed  those  sensations  if  their  supposed  cause  had  been  real.     "  A 
clergyman  told  me,  that  some  time  ago  suspicions  were  entertained  in  his  parish, 
of  a  woman  who  was  supposed  to  have  poisoned  her  newly-born  infant.     The 
coffin  was  exhumed,  and  the  procurator-fiscal,  who  attended  with  the  medical  men 
to  examine  the  body,  declared  that  he  already  perceived  the  odour  of  decompo- 
sition, which  made  him  feel  faint,  and  in  consequence  he  withdrew.     But,  on 
opening  the  coffin,  it  was  found  to  be  empty;    and  it  was  afterwards  ascertained 
that  no  child  had  been  born,  and  consequently  no  murder  committed." — The 
second  case  is  yet  more  remarkable.      "  A  butcher  was  brought  into  the  shop  of 
Mr.  Macfarlan,  the  druggist,  from  the  market-place  opposite,  labouring  under  a 
terrible  accident.     The  man,  on  trying  to  hook-up  a  heavy  piece  of  meat  above 
his  head,  slipped,  and  the  sharp  hook  penetrated  his  arm,  so  that  he  himself  was 
suspended.     On  being  examined,  he  was  pale,  almost  pulseless,  and  expressed 
Limself  as  suffering  acute  agony.     The  arm  could  not  be  moved  without  causing 
excessive  pain;  and  in  cutting-off  the  sleeve,  he  frequently  cried  out;  yet  when 
the  arm  was  exposed,  it  was  found  to  be  quite  uninjured,  the  hook  having  only 
traversed  the  sleeve  of  his  coat !" — In  this  and  similar  cases,  the  sensation  was 
perfectly  real  to  the  individual  who  experienced  it ;  but  it  originated  in  a  Cere- 

1  See  his  valuable  Essay  on  that  subject  in  his  "Medical  Notes  and  Reflections,"  and  in 
tr.s  "  Chapters  on  Mental  Physiology." 
8  "  The  Mesmeric  Mania  of  1851."     Edinburgh,  1851. 


OF    SENSATIONAL    CONSCIOUSNESS.  553 

bral  (ideational)  change,  which  produced  its  impression  through  the  nerves  of 
internal  sensation  (§  566),  instead  of  in  an  impression  upon  the  nerves  of  the 
external  senses  to  which  it  was  referred.  Of  this  kind  of  action  we  shall  see 
other  examples,  in  the  production  of  sensations  by  '  suggestion'  in  the  state  of 
artificial  Reverie  (§  672).  And  the  excitement  of  the  peculiar  sensation  of  tick- 
ling in  a  'ticklish'  person  by  any  movement  that  suggests  the  idea,  and  of  that 
of  creeping  or  itching  by  the  mention  of  bed-infesting  insects  to  those  who  are 
peculiarly  liable  to  their  attacks,  are  familiar  instances  of  the  same  fact ;  which 
strongly  confirms  the  general  doctrines  heretofore  advanced,  respecting  the 
analogy  between  the  peripheral  surface  of  the  Cerebrum  and  the  peripheral 
expansions  of  the  Sensory  nerves,  as  regards  their  mutual  relations  to  the 
Sensorium  (§  577). 

602.  On  the  same  level  with  the  simple  feelings  of  pleasure  and  pain  which 
are  associated  with  our  Sensational  consciousness,  but  distinct  from  these  in  the 
manner  in  which  they  affect  us,  are  those  general  feelings  of  personal  well-being, 
or  of  its  reverse  malaise,  which,  whilst  so  intimately  connected  with  states  of  the 
bodily  system  as  to  be  producible  by  them  alone,  are  also  the  rudimentary  forms 
of  those  higher  psychical  states  which  we  term  Emotions.  These  feelings,  in 
their  lowest  stage  of  development,  are  purely  subjective;  the  individual  being 
simply  conscious  of  them,  and  not  referring  them  to  any  external  source.  There 
are  many  persons  who  are  so  keenly  susceptible  of  both,  that  they  pass  their 
whole  lives  in  an  alternation  between  cheerfulness  and  depression ;  the  former 
state  being  favoured  by  freedom  from  anxiety,  by  the  healthful  activity  of  all  the 
organic  functions,  by  a  bright  sun  and  a  dry  bracing  atmosphere;  whilst  the 
latter  is  immediately  induced  by  mental  disquietude,  by  a  slight  disorder  of 
digestion  or  excretion,  or  by  a  dull  oppressive  day.  And  a  concurrence  of  favour- 
able conditions  may  even  exalt  this  Cwncesthesis  (or  self-feeling)  into  exhilaration 
or  absolute  joy  ;  whilst  the  combined  influence  of  those  of  the  opposite  kind  may 
produce  gloom  which  may  be  exaggerated  almost  to  despair.  The  condition  of 
'  the  spirits'  (as  these  mental  affections  are  commonly  designated)  most  to  be 
desired,  however,  is  that  of  tranquil  comfort ;  for  this  is  far  more  favourable 
than  the  alternation  of  extremes,  to  healthful  activity  and  to  sustained  energy, 
both  of  body  and  of  mind.  And  this  may  be  cherished  by  cultivating  the  habit 
of  Volitional  self-restraint  (§  462),  whereby  any  tendency  to  undue  exhilaration 
is  moderated,  and  excessive  depression  is  resisted  by  a  determinate  effort  not  to 
yield  to  it. — The  same  states  of  consciousness  may  be  excited  by  causes  purely 
Psychical ;  and  although  we  are  then  accustomed  to  designate  them  as  Emotions, 
yet  their  nature  and  their  seat  are  probably  the  same  in  the  one  case  as  the 
other.  For  if,  like  the  Sensations  with  which  they  are  so  closely  associated,  they 
are  impressed  on  our  consciousness  by  the  instrumentality  of  the  Sensory  Ganglia, 
it  is  easy  to  see,  on  the  principles  already  explained,  how  they  may  be  called 
into  activity  by  impressions  conveyed  thither  by  the  'nerves  of  the  internal  senses/ 
as  well  as  by  those  which  arrive  there  through  the  '  nerves  of  common  sensation' 
which  are  distributed  through  the  body.  It  often  happens,  moreover,  that  the 
impression  thus  made  upon  the  *  Emotional  sensibility'  is  more  persistent  than 
the  mental  state  which  gave  rise  to  it ;  for  after  some  disagreeable  occurrence, 
or  the  receipt  of  ill-tidings,  we  feel  an  abiding  consciousness  of  discomfort  or 
distress,  although  we  determinately  keep  from  our  mental  view  the  recollection 
of  the  unpleasant  idea,  in  order  that  we  may  not  be  disturbed  by  dwelling  too1 
painfully  on  it.  It  may  often  be  observed,  moreover,  that  when  the  passions 
have  been  excited  in  states  of  Somnambulism,  Hypnotism,  &c.,  a  disturbed 
Caenaesthesis  is  carried-on  into  the  ordinary  state,  although  the  '  subject'  is  alto- 
gether unconscious  of  the  nature  or  causes  of  the  Emotional  paroxysm.1 — There 
are  few  other  forms  of  Emotional  sensibility,  which  are  so  completely  subjective 

1  For  a  remarkable  case  of  this,  see  the  Author's  Art.  Sleep,  in  the  "Cyclop   of  Auat 
and  Pays.,"  vol.  iv  p.  693. 


554  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

as  the  foregoing;  most  of  th^m  having  reference  to  some  object  which  is  felt  to 
be  external  to  self,  and  therefore  belonging  to  the  next  category.  But  we  seem 
justified  in  referring  to  this  group,  as  being  nearly  allied  to  the  foregoing,  though 
scarcely  capable  of  being  grouped  together  with  them,  the  sense  of  enjoyment  in 
activify,  and  its  converse  the  sense  of  tedium  in  inactivity  (commonly  known  as 
ennui) ;  both  of  which  are  purely  subjective  states,  and  are  obviously  mani- 
fested by  the  lower  animals,  chiefly,  however,  in  connection  with  their  bodily 
functions,  whilst  in  Man  it  is  the  want  of  mental  occupation  that  is  the  chief 
source  of  Ennui. 

603.  Perceptive  and  Intuitional  Consciousness. — Neither  the  operations  of  the 
Intellectual  Powers,  nor  the  higher  Emotional  states,  are  immediately  called- 
forth  by  the  Sensational  consciousness  ;  for  if  we  do  not  advance  beyond  this,  we 
merely  recognize  the  fact  that  certain  changes  have  occurred  in  our  own  l  sub- 
jective state,  and  do  not  refer  these  changes  to  any  external  or '  objective  '  source. 
Of  such  a  limitation,  we  occasionally  meet  with  examples  among  the  phenomena 
of  Dreaming,  and  in  some  of  the  conditions  resulting  from  the  use  of  Anaesthetic 
agents;  for  if  we  fall  asleep  whilst  suffering  from  bodily  pain,  we  may  entirely 
lose  all  perception  of  the  cause  of  that  pain  as  having  its  seat  in  our  own  bodily 
fabric,  and  yet  remain  conscious  of  a  perturbed  state  of  feeling ;  and  when  a  sur- 
gical operation  is  performed  in  a  state  of  incomplete  Anaesthesia,  it  is  obvious 
that  pain  is  felt  without  any  distinct  consciousness  of  its  source,  and  the  patient 
may  subsequently  describe  his  state  as  an  uneasy  dream.     Such,  it  is  probable, 
is  the  condition  of  the  Infant  at  the  commencement  of  its  psychical  life.     '  If,'  as 
has  been  well  remarked  by  Mr.  Morell,1  "  we  could  by  any  means  transport  our- 
selves into  the  mind  of  an  infant  before  the  perceptive  consciousness  is  awakened, 
we  should  find  it  in  a  state  of  absolute  isolation  from  everything  else  in  the  world 
around  it.     Whatever  objects  may  be   presented  to  the  eye,   the  ear,  or  the 
touch,  they  are  treated  simply  as  subjective  feelings,  without  the  mind's  possess- 
ing any  consciousness  of  them,  as  objects  at  all.     To  it,  the  inward  world  is 
everything,  the  outward  world  is  nothing." — However  difficult  it  may  be,  under 
the  influence  of  our  life-long  experience,  to  dissociate  any  sensation  of  which  we 
are  cognizant,  from  the  notion  of  its  external  cause — since  the  moment  the  feel- 
ing is  experienced,  and  the  mind  is  directed  to  it,  the  object  from  which  it  arises 
is  immediately  suggested, — yet  nothing  is  more  certain  than  that  all  of  which  we 
are  ourselves  conscious,  in  any  case  whatever,  is  a  certain  internal  or  subjective 
state,  a  change  in  our  previous  consciousness;  and  that  the  mental  recognition 
of  the  object  to  which  that  change  is  due,  is  dependent  upon  a  higher  mental 
process,  to  which  the  name  of  Perception  or  Perceptive   Consciousness  is  now 
generally  accorded.     We  may  recognize  the  manifestation  of  this  process  in  the 
child,  as  it  advances  beyond  the  first  few  months  of  its  helplessness.     "  A  sight 
or  a  sound,"  remarks  Mr.  Morell  (Op.  cit.),  "which  at  first  produced  simply  an 
involuntary  start,  now  awakens  a  smile  or  a  look  of  recognition.     The  mind  is 
evidently  struggling  out  of  itself ;  it  begins  to  throw  itself  into  the  objects  around, 
and   to  live  in   the  world  of  outward  realities/'     A   similar  transition,  more 
rapidly  effected,  may  be  distinguished  in  ourselves,  during  the  passage  from 
sleep,  or  from  the  insensibility  of  a  swoon,  to  the  state  of  complete  wakefulness; 
when  we  are  at  first  conscious  only  of  our  own  sensations,  and  gradually  come  to 
the  knowledge  of  our  condition  as  it  relates  to  the  world  around,  and  of  the 
position  and  circumstances,  new  and  strange  as  they  may  be,  in  which  we  find 
ourselves. 

604.  Now  the  apprehension,  or  formation  of  an  elementary  notion,  of  the  out- 
ness or  externality2  of  the  cause  of  a  sensational  change,  is  an  operation  which 

"Philosophy  of  Religion,"  p.  7. 

'  This  term  is  to  be  understood  in  the  present  inquiry,  as  implying  what  is  external  t^ 
the  mind.  Viewed  in  that  aspect,  the  bodily  organism  stands  in  the  same  kind  of  relation 
to  it.  as  does  the  world  beyond  ;  and  the  changes  in  the  former  which  give  rise  to  sensations, 
are  as  much  objective  as  are  those  of  the  latter. 


OF  PERCEPTION  AND  INTUITIONAL  CONSCIOUSNESS.      555 

the  Mind  seems  necessarily  to  perform,  when  it  has  attained  a  certain  stage  of 
development;  instinctively  or  intuitively  making  a  definite  distinction  between 
the  self  and  the  not-self,  the  subject  and  the  object.     We  do  not  infer  the  exist- 
ence of  objective  realities  by  any  act  of  the  Reason ;  in  fact,  the  strict  applica- 
tion of  logical  processes  tends  rather  to  shake  than  to  confirm  the  belief  in  the 
external  world ;  but  the  qualities  of  matter  are  directly  and  immediately  recog- 
nized by  our  minds,  and  we  gradually  learn  to  interpret  and  combine  the  impres- 
sions they  make  upon  our  consciousness,  so  as  to  derive  from  them  a  more  or  less 
definite  notion  of  the  object.     Some  of  these  notions  are  so  simple,  and  so  con- 
stantly excited  by  certain  sensations,  that  we  can  scarcely  do  otherwise  than 
attribute  their  formation  to  original  and  fundamental  properties  of  the  mind, 
called  into  activity  by  the  sensations  in  question ;  thus,  the   notion  of  hardness 
seems  to  connect  itself  from  the  first  with  the  sense  of  absolute  resistance,  the 
notion  of  direction  with  the  consciousness  of  diversity  of  parts  in  the  visual  pic- 
ture.    Such  perceptions  are  said  to  be  intuitive  or  original.     In  other  cases, 
however,  the  notions  are  connected  with  the  sensations  by  habit  alone ;  and  it  is 
entirely  due  to  the  association  which  gradually  establishes  itself  between  them, 
that  the  one  calls-up  the  other.     This  is  certainly  the  case  with  regard  to  those 
perceptions  of  the  relative  distances  of  remote  objects,  which  are  based  upon  our 
apprehension  of  their  sizes,  the  distinctness  with  which  they  are  seen,  &c.  (§  764); 
but  with  regard  to  our  visual  perception  of  solidity  or  projection  (§  761),  which 
depends  upon  an  appreciation  of  the  relative  distances  of  the  several  parts  of  a 
near  object  (§  763),  it  will  be  shown  to  be  questionable  whether  this  is  intuitive, 
or  whether  it  is  acquired  by  the  early  combination  of  the  visual  and  tactile  sen.se- 
perceptions.     Certain  it  is,  that  during  the  period  of  infancy,  a  very  rapid  and 
energetic  process  of  self-education  is  going  on  ;  the  whole  mind,  so  far  as  it  is  yet 
developed,  being  concentrated  upon  its  perceptive  activity.     And  the  judicious 
parent  or  nurse  will  favour  this  process,  by  supplying  a  sufficient  varie'ty  of  ob- 
jects on  which  it  may  be  advantageously  exercised. — When  once  a  complete 
interpretation  has  thus  been  attained,  of  any  particular  group  of  sensations,  it  so 
immediately  occurs  to  the  consciousness  whenever  those  sensations  maybe  renewed, 
as  to  have  all  the  directness  of  an  original  perception ;  and  thus  it  is  very  diffi- 
cult, at   later  periods  of  life,  to  discriminate  the  perceptions  which  are  really 
intuitive,  from  those  which  have  been  acquired'  during  infancy.     It  would  be 
wrong  to  draw  inferences  on  this  point  from  the  actions  of  the  lower  animals ;  for 
in  those  cases  in  which  the  young  are  dependent  from  the  first  on  the  exertion 
of  their  own  powers,  it  is  obvious  that  they  have  a  larger  range  of  intuitive  per- 
ceptions, than  is  possessed  by  those  which  derive  their  early  sustenance  from  their 
parents.     Many  of  them,  for  example,  manifest  a  guiding  appreciation  of  direc- 
tion and  distance,  which  Man  can  only  gain  by  long  experience.     Thus,  a  fly- 
catcher just  come  out  of  its  shell,  may  be  seen  to  peck-at  and  capture  an  insect, 
with  an  aim  as  perfect  as  if  it  had  been  all  its  life  engaged  in  learning  the  art. 
Still  more  remarkable  is  the  perception  that  guides  the  actions  of  a  little  fish,  the 
Chsetodon  rostratus,  which  shoots-out  drops  of  fluid  from  its  prolonged  snout,  so 
as  to  strike  insects  that  happen  to  be  near  the  surface  of  the  water,  thus  causing 
them  to  fall  into  it,  so  as  to  come  within  its  own  reach.     Now  by  the  laws  of  re- 
fraction of  light,  the  real  place  of  the  Insect  in  the  air  will  not  be  that  at  which 
it  appears  to  the  Fish  in  the  water;  but  it  will  be  a  little  below  its  apparent 
place,  and  to  this  point  the  aim  must  be  directed.     But  the  difference  between 
the  real  and  the  apparent  place  will  not  be  constant ;  for  the  more  perpendicu- 
*  larly  the  rays  enter  the  water,  the  less  will  be  the  variation  ;  and,  on  the  other 
hand,  the  more  oblique  the  direction,  the  greater  will  be  the  difference.     Now  it 
is  impossible  to  imagine  but  that,  by  an  intuitive  perception,  the  real  place  of  the 
Insect  is  made  known  to  the  Fish  in  every  instance,  as  perfectly  as  it  could  be  to 
the  most  sagacious  Human  mathematician  who  might  determine  it  in  each  case 
fiy  a  process  of  calculation,  or  to  a  clever  marksman  who  had  learned  it  pmoti- 


556  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

cally  by  a  long  experience.  The  Fish,  however,  simply  acts  upon  such  know- 
ledge, prompted  by  an  instinctive  impulse  to  do  so ;  whilst  Man,  even  in  the 
lowest  stage  of  his  culture  (as  when  in  the  condition  of  the  child  or  the  savage), 
consciously  separates  his  own  personality  from  the  object  which  excites  his 
mental  activity;  and  thus  only  can  he  lay  the  foundation  for  exercising  that 
higher  Intelligence,  which  supersedes  in  him  the  Instinct  of  the  lower  animals. 

605.  The  formation  of  acquired  perceptions,  and  their  gradual  assumption  of 
the  immediate  character  of  those  which  belong  to  our  original  constitution  (thus 
deserving  the  designation  of  secondarily-intuitive),  bear  a  striking  analogy  to  the 
process  by  which  habitual  movements  come  to  be  linked-on  to  the  sensations  that 
prompt  them,  so  as  at  last  to  be  automatically  performed,  although  originally 
guided  by  the  Will  (§  540).  And  it  can  scarcely  be  regarded  as  improbable, 
that,  in  the  one  case  as  in  the  other,  the  nervous  mechanism  grows-to  particular 
modes  of  activity  (§  515);  so  that  successions  of  action  are  uniformly  excited 
by  particular  stimuli,  which  were  not  provided-for  in  its  original  construction. 
Such  a  view  harmonizes  well  with  the  fact,  that  such  associations,  both  between 
sensations  and  respondent  movements,  and  between  sensations  and  respondent 
ideas,  are  formed  much  more  readily  during  the  period  of  childhood  and  adoles- 
cence, than  they  are  after  the  full  measure  of  development  has  been  attained ; 
and  that  they  are  much  more  durable  in  the  former  case  than  in  the  latter.  For 
that  which  has  been  already  pointed-out  with  regard  to  the  nutrition  of  other 
tissues  (§  346),  may  not  unreasonably  be  applied  to  the  Nervous  system ;  that, 
when  once  a  certain  mode  of  nutrition  has  been  fully  established,  it  tends  to 
perpetuate  itself,  provided  that  it  be  not  altogether  unconformable  to  the  original 
type.  Throughout  the  whole  constitution  of  Man,  physical  and  mental,  we  wit- 
ness this  capacity  of  adaptation  to  a  great  variety  of  circumstances ;  and  it  seems 
to  be  purposely  left  to  Man  to  educate  himself  in  accordance  with  those  circum- 
stances, so  that  he  gradually  acquires  those  modes  of  action,  which  in  other 
animals  are  directly  prompted  by  instinctive  or  intuitive  tendencies.  Hence 
although  placed  at  a  disadvantage  in  comparison  with  them,  during  the  earlier 
periods  of  his  life,  he  is  enabled  ultimately  to  attain  to  a  far  wider  range  of  per- 
ceptive appreciation,  than  that  to  which  they  are  limited ;  there  being,  in  fact, 
no  class  of  sensory  impressions,  from  which,  by  habitual  attention  to  them,  he 
may  not  draw  information  of  a  far  more  precise  and  varied  nature  than  they 
seemed  at  first  to  be  capable  of  affording. 

606.  We  have  seen  that,  for  the  production  of  a  Sensation,  a  ctmscious  state  of 
mind  is  all  that  is  required ;  whilst,  on  the  other  hand,  for  the  exercise  of  the 
Perceptive  power,  a  certain  degree  of  attention  is  requisite ;  or,  in  other  words, 
the  Mind  must  be  directed  towards  the  sensation.  And  thus  it  happens  that, 
when  the  mind  is  either  inactive,  or  is  completely  engrossed  by  some  other  sub- 
ject of  thought,  the  sensation  may  neither  be  perceived  nor  remembered,  not- 
withstanding that  we  have  evidence  derived  from  the  respondent  movements  of 
the  body,  that  it  has  been  felt.  Thus  a  person  in  a  state  of  imperfect  sleep  may 
start  at  a  loud  sound,  or  may  turn-away  from  a  light  shining  on  his  face ;  bein«. 
conscious  of  the  sensation  and  acting  automatically  upon  it,  but  forming  no  kint; 
of  appreciation  of  the  externality  of  its  source.  And,  in  like  manner,  a  person 
in  a  state  of  profound  Abstraction  (§  671)  may  perform  many  automatic  move- 
ments, which  cannot  (so  far  as  we  know)  be  excited  except  through  the  medium 
of  sensation  ;  and  yet  the  exciting  sensations  are  neither  perceived  by  him  at  the 
time,  nor  are  they  afterwards  remembered ;  so  that  when  he  is  aroused  from  his 
reverie,  he  may  be  astonished  to  find  himself  in  circumstances  altogether  different 
from  those  under  which  he  passed  into  it.  Sometimes,  however,  the  sensorial 
impression  may  excite  a  sort  of  imperfect  perception,  which  is  subsequently 
remembered  and  completed.  For  example,  the  student  who  does  not  hear  the 
repeated  strokes  of  the  clock  when  his  mind  is  entirely  given-tip  to  his  object  of 
pursuit,  may  have  a  sort  of  vague  consciousness  of  them  if  his  attention  be  less 


OF   PERCEPTIVE   AND   INTUITIONAL    CONSCIOUSNESS.  557 

completely  engrossed  by  bis  studies;  and  although  the  sounds  may  not  suggest 
at  the  moment  any  distinct  idea  of  the  passage  of  time,  yet,  when  he  subsequently 
gives  his  attention  to  the  sensorial  impression,  he  may  remember  to  have  heard 
the  clock  strike,  and  may  even  be  able  to  retrace  the  number  of  strokes.1  When 
the  Attention  is  directed,  however,  to  the  sonorous  impressions  (as  when  we  are 
listening  for  the  striking  of  the  clock),  or  when  it  is  not  so  closely  fixed  on  any 
other  object  as  to  prevent  it  from  being  attracted  by  the  sensations,  the  sounds 
are  not  only  recognized  as  proceeding  from  an  external  source,  which  is  a  simple 
act  of  Perception,  but  the  sensations  which  we  perceive  are  discriminated  from 
all  others  of  like  nature;  and  it  is  by  this  kind  of -mental  intensification  of  the 
perceptive  change  to  which  they  give  rise,  that  the  sensations  themselves  are 
impressed  with  so  much  additional  force  on  our  consciousness,  as  to  seem  extra- 
ordinarily increased  in  acuteness.  Although  we  are  accustomed  to  see  this  chiefly 
in  cases  where  some  particular  kind  of  perceptive  acuteness  has  been  acquired 
by  habit,  yet  we  may  learn  from  certain  phenomena  of  Somnambulism  (both 
spontaneous  and  artificial)  that  nothing  more  is  needed,  than  that  concentration 
of  the  whole  mind  upon  the  sensorial  indications,  which  is  the  natural  state  of 
the  Infant  (§  694). 

607.  The  attainment  of  that  grade  of  Mental  development  which  enables  us 
to  apprehend  the  objective  reality  of  external  things,  seems  to  give  us  also  cer- 
tain elementary  intuitions  in  regard  to  them,  which  are  nearly  akin  to  the  feel- 
ings immediately  associated  with  Sensations  (§  602),  but  which  constitute  the 
germs  (so  to  speak)  of  higher  forms  of  consciousness.     Thus  the  ^Esthetic  sense 
of  the  beautiful,  of  the  sublime,  of  the  harmonious,  &c.,  seems  in  its  most  ele- 
mentary form  to  connect  itself  immediately  with  the  perceptions  which  arise  out 
of  the  contact  of  our  Minds  with  external  Nature.     "  All  those"  says  Mr.  Morell, 
"  who  have  shown  a  remarkable  appreciation  of  form  and  beauty,  date  their  first 
impressions  from  a  period  lying  far  behind  the  existence  of  definite  ideas  or 
verbal  instruction.      The  germs  of  all  their  .^Esthetic  impressions  manifested 
themselves,  first  of  all,  as  a  spontaneous  feeling  or  instinct,  which,  from  the 
earliest  dawn  of  reason,  was  awakened  by  the  presentation  of  the  phenomena 
which  correspond  objectively  with  it  in  the  universe."     These  intuitional  feelings 
exist  in  very  different  intensity  in  different  individuals;  and  it  is  where  they  have 
most  strongly  manifested  themselves  at  a  very  early  period  of  life  (the  sense  of 
harmony,  for  example,  in  the  infant  Mozart),  that  we  can  see  how  fundamental 
a  part  of  our  nature  they  constitute,  although  they  may  be  but  faintly  shadowed- 
forth  in  a  large  part  of  mankind.     They  are  peculiarly  susceptible  of  development, 
however,  by  appropriate  culture ;  under  the  influence  of  which  they  not  merely 
grow-up  in  the  individual,  but  manifest  themselves  with  increased  vigour  and 
more  extended  range  in  successive  generations  of  mankind. 

608.  So,  too,  there  seems  to  lie  in  this  part  of  our  psychical  nature,  the  germ 
which,  in  a  higher  phase  of  development,  is  evolved  into  the  Moral  Sense.    Expe- 
rience shows,  as  Mr.  Morell  justly  remarks,  "that  an  instinctive  apprehension  of 
right  and  wrong,  as  attached  to  certain  actions,  precedes  in  the  child  any  distinct 
comprehension  of  the  language  by  which  we  convey  moral  truths.     Moreover,  the 
power  and  the  purity  of  moral  feeling  not  unfrequently  exist  even  to  the  highest 
degree,  amongst  those  who  never  made  the  question  of  morals  in  any  way  the 
object  of  direct  thought,  and  may  perchance  be  unconscious  of  the  treasure  they 
possess  in  their  bosoms."     And  it  is  only  in  so  far  as  the  doctrines  of  Ethical 

1  It  is  curious  that  in  so  retracing  a  number,  we  are  often  assisted  by  mentally  repro- 
ducing the  succession  of  strokes,  imagining  their  recurrence,  until'  we  feel  that  we  have 
counted-up  to  the  impression  that  was  left  upon  our  sensorium.  In  the  same  way,  if  asked 
how  many  stairs  there  are  in  a  stair-case  which  we  are  in  the  habit  of  using,  we  may  not 
be  able  to  name  the  number ;  yet,  when  actually  ascending  or  descending,  we  are  conscious 
that  we  have  arrived  at  the  top  or  the  bottom,  by  the  completion  cf  that  series  of  sensoria) 
changes  which  have  become  habitual  to  us. 


558  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS    SYSTEM. 

science  are  based  upon  these  fundamental  intuitions  of  our  nature,  that  they 
possess  a  firm  hold  upon  our  convictions  as  necessary  truths. — "  Closely  connected 
with  the  Moral  are  the  Religious  intuitions  of  the  soul;  which  are  developed, 
more  or  less  distinctly,  amongst  the  earliest  of  our  Human  Sentiments,  in  that 
form  of  awe,  veneration,  and  reverence,  which  is  inspired  by  objects  of  sublimity, 
grandeur,  vastness,  and  mystery." — (Morell.)  It  is  by  their  appeal  to  these 
intuitive  feelings  of  reverence,  and  to  the  Moral  sentiment  of  goodness,  that 
religious  teachings  make  their  first  impression  on  the  understanding,  and  lay  the 
foundation  for  those  more  definite  ideas  of  the  Divine  Being,  towards  which,  in 
a  higher  phase  of  religious  development,  we  direct  our  consciousness  of  depend- 
ence, and  our  desire  of  self-elevation ;  and  which  we  invest  intellectually  with 
those  attributes  which  represent  our  highest  ideal  of  Power,  Wisdom,  and  Good- 
ness (§  616) 

609.  The  Moral  and  Religious  intuitions  are  closely  related  to  those  forms  of 
our  Emotional  sensibility,  which,  being  no  longer  purely  subjective,  require  as 
a  condition  of  their  existence  that  they  shall  relate  to  an  external  object.  This 
is  pre-eminently  the  case  with  all  those  which  are  termed  '  emotions  of  sympa- 
thy ;'  thus,  the  perception  of  the  pain  or  distress  of  another  instinctively  excites 
(except  in  individuals  of  a  peculiarly  unsympathetic  temperament)  a  correspond- 
ing affection  in  the  percipient  mind,  just  as  the  sight  of  certain  bodily  move- 
ments (as  yawning)  tends  to  call  forth  the  same  movements  in  ourselves ;  and 
the  opposite  state  of  cheerfulness  or  mirth  has  a  like  tendency  to  affect  those  who 
are  brought  into  contact  with  it,  provided  that  there  be  nothing  positively  antago- 
nistic in  their  own  condition.  But  further,  the  perception  of  enjoyment  calls-forth 
a  respondent  gladness;  whilst  the  perception  of  suffering  tends  to  excite  in  our- 
selves that  feeling  of  sorrow  which  we  term  pity,  and  either  of  these  feelings 
may  be  experienced,  even  when  we  do  not  ourselves  share  in  the  state  of  eleva- 
tion or  depression  which  excited  them. — More  closely  connected  with  the  fore- 
going than  is  commonly  conceived,  is  that  sense  of  the  humorous,  which  attaches 
itself  to  certain  manifestations  of  character  presented  to  us  in  the  actions  of  others ; 
that  sympathy  with  Human  nature  in  which  the  former  have  their  source,  being 
the  foundation  of  the  latter  also ;  and  thus  it  happened  that  those  writers  who 
have  the  strongest  power  of  exciting  our  sense  of  humour,  are  usually  distin- 
guished also  by  their  mastery  of  the  pathetic.  To  the  sense  of  the  humorous, 
that  of  the  ludicrous  is  obviously  related  ;  but  this,  when  excited  by  operations 
of  the  intellect,  instead  of  by  external  objects,  belongs  to  a  different  category 
(§  619).  The  same  may  be  said  of  the  sense  of  wonder;  which  in  its  simplest 
form  may  be  connected  with  our  sense-perceptions,  but  which  is  more  commonly 
experienced  in  regard  to  the  ideas  which  they  excite. — Another  group  of  Emo- 
tional feelings  belonging  to  the  same  category,  is  that  which  may  receive  the 
general  designation  of  Attractions  and  Repulsions.  These  are  the  elementary 
states  of  those  Emotions  which  involve  a  distinct  idea  of  the  object  which  attracts 
or  repels,  and  which  then  assume  the  forms  of  desires  and  aversions  (§  619);  but 
it  is  in  this  form  that  they  seem  to  act  in  the  lower  animals  and  in  young  children, 
whose  minds  are  not  yet  fully  developed  into  the  stage  of  ideational  conscious- 
ness. The  various  terms  like  and  dislike,  partiality  and  distaste,  love  and  hatred, 
which  we  use  to  signify  the  modes  in  which  we  ourselves  feel  affected  by  external 
objects,  indicate  the  existence  of  this  elementary  form  of  emotional  sensibility  in 
connection  with  the  perceptive  consciousness. — There  are  other  emotional  states, 
some  of  them  rising  to  the  intensity  of  passions,  which  seem  to  belong  to  this 
category ;  but  the  examples  already  cited  are  sufficient  to  illustrate  the  doctrine 
here  contended-for. 

610.  It  is  a  characteristic  peculiarity  of  all  the  modes  of  affection  of  the  con- 
sciousness which  have  been  now  described,  that,  being  the  immediate  experiences 
of  the  percipient  mind,  they  cannot  be  expressed  in  language,  or  conveyed  by 
any  system  of  purposive  signs  to  other  minds ;  although  the  spontaneous  expres- 


OP    IDEATIONAL    CONSCIOUSNESS.  559 

sions  to  which  they  prompt,  may  be  apprehended  by  other  minds  in  a  correspond- 
ing state  of  activity.  "  If,"  says  Mr.  Morell,  "  we  look  along  the  whole  range 
of  our  intuitions,  we  find  them  all  alike  unutterable.  They  may,  indeed,  be  in- 
tensely felt;  their  inward  existence,  too,  may  be  manifested  by  a  thousand  sig- 
nificant indications;  nay,  they  can  create  an  impulse  and  a  sympathy  in  others, 
by  the  very  light  they  kindle  in  the  features,  and  the  power  they  infuse  into  the 
actions  of  those  who  intensely  realize  them ;  but  they  cannot  be  articulately  ex- 
pressed." It  is  only  when  they  are  evolved  into  those  representative  forms  which 
are  termed  Ideas  (§  613),  that  they  are  capable  of  being  expressed  by  a  language 
either  of  signs  or  of  sounds.  And  it  may  be  noticed  that  long  before  children 
have  attained  to  any  comprehension  of  these,  they  intuitively  interpret  the  ex- 
pressions of  Emotion,  and  are  sympathetically  affected  by  them ;  as  seems  the 
case,  too,  with  regard  to  such  of  the  lower  animals  as  habitually  associate  with 
Man,  and  have  acquired  that  sympathy  with  his  emotional  nature,  which  enables 
them  to  recognize  its  manifestations. 

611.  The  Intuitional  consciousness  is  not  solely  exercised,  however,  upon  the 
impressions  transmitted  to  it  through  the  external  senses.     For  it  appears  to  be 
by  a  like  direct  action  of  the  mind  upon  the  products  of  our  higher  Psychical 
operations,  which  come  to  the  Sensorium  through   the  '  nerves  of  the  internal 
senses'  (§  577),  that  we  apprehend  these  as  realities  or  necessary  truths.     Thus 
when,  by  those  Intellectual  processes  of  which  the  Cerebrum  is  the  instrument, 
we  have  evolved  the  abstract  idea  that  "  things  which  are  equal  to  the  same 
thing,  are  equal  to  one  another,"  we  feel  intuitively  compelled  to  recognize  that 
idea  as  a  fact;  and  whilst  no  accumulation  of  appeals  to  experience  would  in- 
crease our  confidence  in  its  validity,  so  the  assertion  that  experience  ever  leads 
to  a  contrary  result,  would  only  call-forth  the  reply  that  such  experience  must  be 
fallacious.     So,  again,  all  logical  reasoning  is  based  upon  the  assumption  of  the 
truth  of  its  methods,  the  only  guarantee  for  which  lies  in  an  appeal  to  the  intui- 
tional consciousness;  and  the  conclusion  can  only  be  certainly  relied-on,  when 
(as  in  Mathematical  proof)  the  basis  of  the  whole  is  an  axiom  or  necessary  truth, 
and  at  every  step  of  the  argument  the  most  indubitable  certainty  can  be  felt  as 
to  the  correctness  of  the  inference. — -And  thus,  in  all  departments  of  human 
knowledge,  the  ultima  ratio  is  afforded  by  our  Intuitional  consciousness ;  which, 
within  the  range  of  its  development,  is  the  most  certain  and  direct  of  all  our 
means  of  apprehending  truth ;  and  which  is  the  faculty  that  seems  most  to  link 
us  to  that  Divine  Intelligence,  whose  all-comprehensive  thought  takes-in  the 
Universe,  with  all  its  past,  present,  and  future,  as  but  a  point  in  its  Infinite  con- 
ception.1 

612.  Of  Ideational   Consciousness.  —  In  ascending  the   scale   of  Psychical 
activity,  we  find  the  operations  of  the  Mind  becoming  more  and  more  detached 
from  the  sensational  changes  which  first  excited  them.     We  have  seen  that  in 
the  first  or  Sensational  stage,  the  consciousness  is  engrossed  with  self,  not  being  as 
yet  awake  to  the  existence  of  any  external  cause  for  the  subjective  change  it  expe- 
riences ;  whilst  in  the  second,  or  Perceptive  stage,  in  which  that  objective  cause  is 
apprehended  as  something  not-self,  the  mind  is  entirely  given-up  to  the  contempla- 
tion of  it ;  and  recognizes  its  properties  as  the  sources  of  the  various  affections 
it  experiences.     Some  of  these  affections  relate  to  knowledge,  whilst  others  par- 
take more  of  the  nature  of  feeling ;  but  in  all  of  them  the  percipient  mind  is 
brought  face  to  face,  as  it  were,  with  the  object  perceived  ;  and  the  intuitive 
knowledge  which  arises  from  this   direct  relation,  has  a  certainty  to  which  no 
other  kind  of  knowledge  can  lay  claim.     But  it  is  not  until  the  Mind  attains  a 
still  higher  kind  of  activity,  that  it  forms  that  distinct  mental  representation.,  or 
Idea,2  of  the  object,  which  stands  altogether  apart  from  our  immediate  expe 

1  On  all  that  relates  to  the  Perceptive  and  Intuitional  Consciousness,  see  especially  Ml, 
J.  D.  Morell's  "Elements  of  Psychology,"  Part  i.  chap.  iv. 

9  The  Author  thinks  it  useless  to  enter  into  the  enquiry  which  has  been  the  subject  of 
so  many  abstruse  and  laboured  Metaphysical  discussions,  as  to  whether  our  fundamental 


5(50  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

rience,  and  assumes  the  character  of  an  independent  intellectual  reality.  In 
forming  this  mental  representation,  the  mind  is  determined  by  the  nature  and 
intensity  of  the  various  affections  of  its  consciousness  which  have  been  excited 
by  the  object;  and  as  these  will  depend  in  part  upon  its  original  constitution, 
and  in  part  upon  the  mode  in  which  it  has  been  habitually  exercised,  it  follows 
that  the  ideas  or  mental  representations  of  the  same  object  or  occurrence,  which 
are  formed  by  different  individuals,  may  be  widely  discrepant.  This,  indeed, 
continually  proves  to  be  the  case ;  and  we  cannot  have  a  better  example  of  the 
fact,  than  is  afforded  by  the  variety  in  the  modes  in  which  the  same  landscape 
shall  be  depicted  by  different  Artists,  each  expressing  in  his  peculiar  l  manner' 
the  representation  which  his  Mind  has  formed  of  that  aspect  of  Nature  which 
it  has  contemplated. — The  influence  of  preconceived  notions,  or  of  fas  feelings 
by  which  the  mind  is  habitually  possessed,  may  be  continually  recognized  by  the 
observant,  as  modifying  the  ideas  which  every  one  forms  of  what  is  presented  to 
his  observation ;  and  it  is  by  an  exaggeration  of  such  influences  that  those  mis- 
representations are  made,  which  in  certain  forms  of  Insanity,  possess  the  mind 
of  the  subject  of  them  with  convictions  that,  to  every  one  else,  are  palpably  in- 
consistent with  reality  (§  711). — This  want  of  conformity  between  the  ideal  and 
the  actual  is  peculiarly  apt  to  arise  in  the  minds  of  those,  who  live  too  much  in 
the  former  and  too  little  in  the  latter;  for  in  proportion  as  the  mind  dwells  too 
exclusively  upon  its  own  conceptions,  and  refrains  from  bringing  these  into  con- 
tact with  the  realities  of  every-day  life,  do  aberrations,  which  would  speedily  be 
checked  by  experience,  progressively  acquire  a  preponderating  influence,  until  at 
last  they  may  acquire  the  character  of  settled  delusions,  and  may  altogether  upset 
the  balance  of  the  intellect. 

613.  The  whole  tendency  of  the  ideational  activity  of  the  Mind,  is  thus  to 
separate  the  representation  which  it  forms  from  the  restraints  of  outward 
experience,  as  completely  as  possible;  so  as  to  make  it  a  distinct  and  intelligible 
object  of  contemplation,  which  can  be  placed,  at  pleasure,  either  within  or  be- 
yond the  grasp  of  the  consciousness,  at  the  moment.  Now  for  the  perfection  of 
this  objectifying  process,  it  is  requisite  that  we  should  possess  some  mode  of 
signifying  our  ideas,  so  that  they  may  at  the  same  time  be  made  clear  and 
distinct  to  ourselves,  and  be  rendered  intelligible  to  other  minds.  This  may  be 
accomplished  by  means  of  signs  visible  to  the  eye,  or  transmissible  through  the 
touch ;  or  by  means  of  spoken  language,  in  which  certain  combinations  of  sounds 
are  made  to  symbolize  ideas.  Now  the  nearer  the  signs  employed  are  to  the 
natural  expressions  of  the  ideas  for  which  they  are  to  stand,  the  more  readily 
are  they  comprehended  by  those  to  whom  they  are  addressed;1  but  their  range 

ideas  originate  altogether  without,  or  altogether  within,  the  Mind ;  or  partly  without  and 
partly  within.  It  will  be  sufficient  for  him  to  express  his  own  conviction,  that  the  latter 
is  the  only  consistent  mode  of  viewing  the  subject,  and  is  that  at  which  any  enquirer  must 
arrive,  who  discusses  all  the  facts  of  the  case  according  to  the  true  method  of  Scientific 
reasoning.  An  idea  can  no  more  correctly  be  designated  a  '  transformed  sensation,'  than 
a  sensation  could  be  designated  a  transformed  impression.  The  one  is  antecedent ;  the 
other  is  consequent.  And  just  as  an  electrical  or  chemical  stimulus,  applied  to  a  Muscle, 
calls  it  into  contraction,  so  does  the  sensational  stimulus,  acting  on  the  percipient  Intel- 
lect, excite  an  idea  of  the  object  which  gave  occasion  to  the  sensation.  On  the  other  hand, 
to  affirm  that  ideas  are  either  'innate,'  or  are  in  any  way  produced  by  the  Mind  itself 
without  original  excitement  by  sensations  ab  extra,  is  a  position  so  entirely  inconsistent  with 
experience,  as  not  to  bear  any  careful  scrutiny.  The  formation  of  Ideas,  then,  may  be 
considered  as  the  reaction  between  the  External  World  and  the  Intelligent  Mind;  the 
latter  possessing  within  itself  certain  properties,  which  the  impressions  made  upon  it  by  the 
former  are  adapted  to  call  into  active  exercise.  —  For  a  concise  view  of  the  various  doc- 
trines which  have  been  propounded  on  this  subject,  and  their  bearing  on  the  "central 
idea  "  which  rests  on  "  the  primary  harmony  between  the  Soul  and  the  Universe,"  see  Mr. 
J.  D.  Morell's  "Elements  of  Psychology,"  pp.  269,  et  seg. 

1  The  deaf-and-dumb  are  trained  to  communicate  with  each  other,  not  merely  by  the 
'  finger-language,'  by  which  words  are  alphabetically  spelled,  but  also  by  the  '  sign-lan- 
guage,' by  which  ideas  are  conveyed  through  the  much  more  direct  medium  of  single  signs. 


OF    IDEATIONAL    CONSCIOUSNESS.  561 

is  necessarily  very  limited,  and  every  family  of  Mankind  has  substituted  for  them 
a  set  of  arbitrary  sounds,  which  are  not  only  much  more  perfect  in  themselves 
as  instruments  for  the  expression  of  ideas,  but  are  capable  of  being  made  to 
convey  (by  means  of  that  wonderful  apparatus  of  articulation  with  which  Man 
is  provided)  an  unlimited  variety  of  meanings,  with  every  kind  of  relation  of 
these  which  the  mind  can  conceive.  In  proportion  as,  by  inflexion  and  combi- 
nation, a  language  is  capable  of  readily  and  precisely  embodying  the  results  of 
the  intellectual  processes,  in  that  proportion  can  these  results  be  objectified  by 
the  individual,  and  be  thus  made  the  basis  of  further  operations ;  and  in  the 
same  proportion  can  they  be  clearly  presented  to  the  minds  of  others,  and  be 
employed  by  them  for  the  same  purpose.  Thus  whilst  the  structure  of  the  lan- 
guage of  any  people  is  to  a  certain  extent  a  measure  of  its  mental  development, 
it  comes  to  exert  a  most  important  influence  over  the  further  progress  and  direc- 
tion of  that  development ;  different  languages  being  in  their  very  nature,  adapted 
for  the  expression,  both  of  different  classes,  and  of  different  relations,  of  ideas. 
Although  some  have  maintained  that  words  which  are  used  to  designate  external 
objects  are  the  signs  of  those  objects,  and  that  such  words  form  a  class  distinct 
from  that  of  the  words  which  stand  as  signs  of  abstract  ideas,  yet  a  little  con- 
sideration will  show,  that  except  in  the  case  of  proper  names1  which  are  only 
applicable  to  individuals,  all  words  really  express  generalized  images  of  the 
objects  to  which  they  refer.  Thus,  if  we  attempt  to  define  the  most  familiar 
object,  such  as  a  house,  a  table,  or  a  basket,  by  any  verbal  description,  we  find  it 
extremely  difficult  to  frame  a  definition  that  shall  include  all  houses,  all  tables, 
all  baskets  j  notwithstanding  that  our  idea  of  a  house,  of  a  table,  or  of  a  basket, 
is  sufficiently  precise  to  enable  us  to  say  at  once  with  regard  to  any  particular 
object,  whether  it  does,  or  does  not  fall  under  one  of  these  categories.  Hence 
they  do  not  appeal  directly  to  the  intuitions  of  other  minds,  but  must  be  compre- 
hended by  translation  through  their  ideational  consciousness.  Thus  it  is,  that 
as  expressions  of  feeling,  words  are  often  less  potent  than  tones  or  gestures, 
which  directly  appeal  to  the  emotional  sensibility  of  the  percipient.  And  thus 
it  is,  too,  that  words  have  no  absolute  meaning,  but  can  only  signify  to  each 
individual  the  ideas  which  he  is  prepared  by  his  previous  habits  of  thought  to 
attach  to  them.2  Words,  in  fact  (as  Mr.  Morell  has  justly  remarked,  Op.  cit.  p. 
194),  "  represent  simply  a  course  of  mental  action,  in  which  we  grasp  the  essen- 

These  signs,  though  partly  conventional,  are  made  to  conform  as  nearly  as  possible  to  the 
natural  expressions  of  ideas  ;  and  are  usually  acquired  very  quickly  by  the  deaf-and-dumb, 
whose  want  of  other  modes  of  utterance  forces  into  activity  a  mode  of  expressing  their 
ideas  and  emotions,  which  is  unnecessary  to  those  who  have  the  command  of  language, 
and  is  consequently  but  little  exerted  by  them.  Young  children,  however,  who  associate 
much  with  the  deaf-and-dumb,  very  readily  acquire  this  'sign-language,'  and  will  often 
prefer  the  continued  use  of  it  to  the  acquirement  of  spoken  language. 

1  To  the  child  first  learning  the  use  of  language,  every  noun  is  originally  a  proper  name, 
standing  as  the  symbol  of  the  individual  object  with  which  it  learns  to  associate  it ;  but 
it  is  very  early  led  by  the  familiar  experiences  of  its  nursery,  to  apply  such  words  as  chair, 
table,  bed,  to  classes  of  objects,  and  thus  to  appreciate  their  significance  as  symbols  of 
generalized  or  abstract  ideas.  And  when  that  process  has  been  accomplished  in  a  few 
instances,  the  child's  intellect  soon  extends  it  to  others ;  its  chief  activity  in  this  state  of 
its  development,  being  directed  to  the  expansion  and  multiplication  of  its  Ideas. 

E  Thus  every  branch  of  knowledge  has  its  own  language,  the  terms  of  which,  even 
when  identical  with  words  in  ordinary  use,  can  only  convey  their  full  and  peculiar  signifi- 
cation to  those  who  have  already  gained  an  extensive  acquaintance  with  the  department  of 
thought  to  which  they  relate.  So  in  rendering  from  one  tongue  into  another,  great  diffi- 
culty is  continually  experienced  in  the  choice  of  words  which  ;->hall  convey  in  the  transla- 
tion the  precise  ideas  signified  in  the  original ;  the  difficulty  oeing  greater  in  proportion  to 
the  diversity  between  the  habits  of  thought  of  the  two  nations  respectively.  We  can 
scarcely  have  a  more  '  pregnant  instance  '  of  the  obstruction  thus  created  to  the  transmis- 
sion of  ideas  through  language,  by  the  peculiarity  of  scientific  terminology  in  combination 
with  diversity  of  national  habitudes  of  thought,  than  is  presented  in  the  attempt  to  bring 
the  abstract  refinements  of  German  Metaphysics  within  the  comprehension  of  a  '  common- 
sense '  English  mind. 

3r* 
w 


562  FUNCTIONS   OF   THE   CEREBRO-SPINAL  NERVOUS   SYSTEM. 

tial  elements  which  distinguish  one  thing  from  another,  and  make  those  elements 
spontaneously  the  ground  for  a  classification  of  our  multifarious  experiences.  In 
this  way  it  is,  that  they  serve  to  construct  the  more  general  outlines  of  human 
knowledge.  Hence  the  wonderful  power  which  words  possess  in  the  whole  process 
of  human  thought;  hence  the  capacity  they  attain,  after  the  teachings  of  experi- 
ence have  paved  the  way,  for  expressing  the  very  essence  of  the  things  to  which 
they  relate ;  hence,  too,  their  use  in  forming  a  broad  platform,  on  which  the 
results  of  all  the  lower  processes  of  mind  are  plainly  recorded,  and  from  which 
we  can  commence  those  higher  forms  of  activity,  which  give  to  Reason  its  all 
but  infinite  range,  and  all  but  omnipotent  force." 

614.  There  are   certain  Ideas  which  seem  almost  necessarily  to  spring-up  in 
the  Mind,  during  the  course  of  its  own  operations ;  and  these,  being  suggested, 
not  so  much  by  perceptions  of  external  objects,  as  by  observation  of  what  is 
taking  place  in  the  Mind  itself,  are   sometimes  distinguished  as  intellectual,  in 
contrast  to  sensational  ideas.     So  universally  do    these  present    themselves  to 
thinking  minds,  so  little  are  they  subject  to  modification  by  peculiarities  of  indi- 
vidual character  (whether  original  or  acquired),  and  so  unhesitatingly  are  they 
recognized  as  truths  when  they  are  judged-of  by  the  Intuitional  consciousness, 
that  they  take  rank  as  fundamental  axioms  or  principles  of  Human  Thought. 
Such  are, — the  belief  in  our  own  present  existence,  or  the  faith  which  we  repose  in 
the  evidence  of  Consciousness;  this  idea  being  necessarily  associated  with  every 
form  and  condition  of  mental  activity  : — the  belief  in  our  past  existence,  and  in 
our  personal  identity  so  far  as  our  memory  extends,  which  is  necessarily  connected 
with  the  act  of  Recollection;  with  this,  again,  is  connected  the  general  idea  of 
Time  : — the  belief  in  the  external  and  independent  existence  of  the  causes  of  our 
sensations,  which  results  from  the  direction  of  the  mind  to  the  Perceptional 
ideas  originating  in  them  ;  with  this  is  connected  the  general  idea  of  Space  :— 
the  belief  in  the  existence  of  an  efficient  cause  for  the  changes  which  we  witness 
around  us,  which  springs  from  the  perception  of  those  changes ;  whence  is  de- 
rived our  idea  of  Power: — the  belief  in  the  stability  of  the  order  of  nature,  or 
in  the  invariable  sequence  of  similar  effects  to  similar  causes,  which  also  springs 
directly  from  the  perception  of  external  changes,  and  seems  prior  to  all  reasoning 
upon  the  results  of  observation  of  them  (being  observed  to  operate  most  strongly 
in  those  whose  experience  is  most  scanty,  and  in  relation  to  subjects  that  are 
perfectly  new  to  them);  but  which  is  the  foundation  of  all  applications  of  our 
own  experience  or  of  that  of  others,  to  the  conduct  of  our  lives,  or  to  the  exten- 
sion of  our  knowledge  : — lastly,  the  belief  in  our  own  free  will,  involving  the 
general  idea  of  Voluntary  Power;  which  is  in  like  manner  a  direct  result  of  our 
internal  perception  of  those  mental  changes  which  are  excited  by  sensations. 
Hence  it  is  evident  that  "  the  only  foundation  of  much  of  our  belief,  and  the 
only  source  of  much  of  our  knowledge,  is  to  be  found  in  the  constitution  of  our 
own  minds;"  but  it  must  be   steadily  kept  in  view,  that  these  fundamental 
Axioms  are  nothing  else  than  expressions  of  the  general  fact,  that  the  ideas  in 
question  are  uniformly  excited  (in  all  ordinarily-constituted  minds  at  least)  by 
simple  Attention  to  the  changes  in  which  they  originate. 

615.  Among  those  elementary  modes  of  thought  which  arise  out  of  the  con- 
stitution of  our  own  minds,  we  must  also  rank  the  ideas  of  Truth,  Beauty,  and 
Right,  which  intuitively  present  themselves  to  our  consciousness,  in  connection 
with  certain  objects  or  occurrences  respectively  adapted  to  excite  them ;  the  first 
connecting  itself  especially  with  the  operations  of  the  Reason,  the  second  with 
those  of  the  Imagination  as  directed  by  the  ^Esthetic  Sense,  and  the  third  with 
the  determination  of  the  Will  in  the  regulation  of  conduct,  under  the  guidance 
of  the  Moral  Sense. —  Truth  may  be  defined  to  be  an  apprehension  of  the  rela- 
tions of  things  as  they  actually  exist;  and  the  conception  of  truth,  which  is 
originally  based  upon  sensational  ideas,  comes  to  be  also  applied  to  those  which 
are  purely  intellectual. — The  notion  of  Beauty,  the  germ  of  which,  as  we  have 


OF    IDEATIONAL    CONSCIOUSNESS.  563 

seen  (§  607),  exists  in  the  Intuitional  Consciousness,  is  one  that  is  very  difficult 
to  define  ;  but  it  seems  to  consist,  when  fully  developed,  in  the  conformity  of  an 
external  object  to  a  certain  ideal  standard,  by  which  conformity  a  pleasurable 
feeling  is  produced.  That  ideal  standard  is  a  work  of  the  Imagination,  and  is 
generated  (by  a  kind  of  automatic  process)  by  the  elimination  of  all  those  ele- 
ments which  we  recognize  as  inferior,  and  by  the  intensification  and  completion 
of  all  those  which  we  regard  as  excellent.  Hence  according  to  the  aesthetic 
judgment  which  every  individual  pronounces  as  to  these  particulars,  will  be  his 
ideal  of  beauty.  The  notion  of  beauty  extends  itself  also  to  the  pure  concep- 
tions of  the  Intellect ;  and  thus  we  may  experience  the  sense  of  beauty  in  the 
recognition  of  a  Truth.  We  experience  the  sense  of  beauty,  too,  in  witnessing 
the  conformity  of  conduct  to  a  high  standard  of  Moral  excellence;  which  ex- 
cites in  our  minds  a  pleasure  of  the  same  order,  as  that  which  we  derive  from 
the  contemplation  of  a  noble  work  of  Art.- — The  idea  of  Right,  also  suggested 
by  the  Intuitional  consciousness,  connects  itself  with  voluntary  action.  We  have 
no  feeling  of  approval  or  disapproval  with  respect  to  actions  that  are  necessarily 
connected  with  our  physical  well-being;  but  in  regard  to  most  of  those  which 
are  left  to  our  choice,  it  is  impossible  to  feel  indifferent;  and  the  sphere  of  ope- 
ration of  this  principle  becomes  widened,  in  proportion  as  the  mind  dwells  upon 
the  notion  of  Moral  Obligation  which  arises  out  of  it.  Then,  too,  the  idea  of 
Right  is  brought  to  attach  itself  to  thoughts,  as  well  as  to  actions;  and  this,  not 
merely  because  the  right  regulation  of  the  thoughts  is  perceived  to  be  essential 
to  the  right  regulation  of  the  conduct,  but  also  because  the  mind  intuitively  per- 
ceives that  whatever  we  can  govern  by  the  Will  has  also  a  moral  aspect 

616.  Closely  connected  with  many  of  the  foregoing,  and  arising  in  most  minds 
from  some  or  other  of  them  by  the  very  nature  of  our  psychical  constitution,  are 
those  ideas  which  relate  to  the  Being  and  Attributes  of  the  Deity.  There  is,  in 
fact,  no  part  of  Man's  psychical  nature,  which  does  not  speak  to  him  of  the 
Divine,  when  it  is  rightly  questioned.  The  very  perception  of  finite  existence, 
whether  in  time  or  space,  leads  to  the  idea  of  the  Infinite.  The  perception  of 
dependent  existence,  leads  to  the  idea  of  the  Self-existent.  The  perception  of 
change  in  the  external  world,  leads  to  the  idea  of  an  Absolute  Power  as  its 
source.  The  perception  of  the  order  and  constancy  underlying  all  those  diver- 
sities which  the  surface  of  Nature  presents,  leads  to  the  idea  of  the  Unity  of 
that  power.  The  recognition  of  Intelligent  Will  as  the  source  of  the  power  we 
ourselves  exert,  leads  to  the  idea  of  a  like  Will  as  operating  in  the  Universe. 
And  our  own  capacity  for  reasoning,  which  we  know  not  to  have  been  obtained 
by  our  individual  exertions,  is  a  direct  testimony  to  the  Intelligence  of  the  Being 
who  implanted  it. — So  are  we  led  from  the  very  existence  of  our  Moral  Feelings, 
to  the  conception  of  the  existence  of  attributes,  the  same  in  kind,  however  ex- 
alted in  degree,  in  the  Divine  being.  The  sense  of  Truth  implies  its  actual 
existence  in  a  being  who  is  Himself  its  source  and  centre ;  and  the  longing  for 
a  yet  higher  measure  of  it,  which  is  experienced  in  the  greatest  force  'by  those 
who  have  already  attained  the  truest  and  widest  view,  is  the  testimony  of  our 
own  souls  to  the  Truth  of  the  Divine  Nature.  The  perception  of  Right,  in  like 
manner,  leads  us  to  the  Absolute  lawgiver  who  implanted  it  in  our  constitution  ; 
and,  as  has  been  well  remarked,  "all  the  appeals  of  innocence  against  unright- 
eous force  are  appeals  to  eternal  justice,  and  all  the  visions  of  moral  purity  are 
glimpses  of  the  infinite  excellence."  The  aspirations  of  the  most  exalted  moral 
natures  after  a  yet  higher  state  of  Holiness  and  Purity,  can  only  be  satisfied  by 
the  contemplation  of  such  perfection  as  no  merely  Human  being  has  ever  attained  : 
and  it  is  only  in  the  contemplation  of  the  Divine  Ideal,  that  they  meet  their 
appropriate  object.  And  the  sentiment  of  Beauty,  especially  as  it  rises  from 
the  material  to  the  spiritual,  passes  beyond  the  noblest  creations  of  art  and  the 
most  perfect  realization  of  it  in  the  outward  life,  and  soars  into  the  region  of  the 
Unseen,  where  alone  the  imagination  can  freely  expand  itself  in  the  contenipla- 


564  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

tion  of  such  Beauty  as  no  objective  representation  can  embody. — And  it  is  by 
combining,  so  far  as  our  capacity  will  admit,  the  ideas  which  we  thus  derive  from 
reflection  upon  the  facts  of  our  own  consciousness,  with  those  which  we  draw 
from  the  contemplation  of  the  Universe  around  us,  that  we  form  the  justest  con- 
ception of  the  Divine  Being,  of  which  our  finite  minds  are  capable.  We  are  led 
to  conceive  of  Him  as  the  Absolute,  Unchangeable,  Self-Existent, — Infinite  in 
duration, — Illimitable  in  space, — the  highest  ideal  of  Truth,  Eight,  and  Beauty, — 
the  All-Powerful  source  of  that  agency  which  we  recognize  in  the  phenomena 
of  Nature, — the  All-Wise  designer  of  that  wondrous  plan,  whose  original  perfec- 
tion is  the  real  source  of  the  uniformity  and  harmony  which  we  recognize  in  its 
operation, — the  All-Benevolent  contriver  of  the  happiness  of  His  sentient  crea- 
tures,— the  All-Just  disposer  of  events  in  the  Moral  World,  for  the  evolution  of 
the  ultimate  ends  for  which  Man  was  called  into  existence.  In  proportion  to 
the  elevation  of  our  own  spiritual  nature,  and  the  harmonious  development  of  its 
several  tendencies,  will  be  the  elevation  and  harmoniousness  of  our  conception  of 
the  Divine ;  and  in  proportion,  more  particularly,  as  we  succeed  in  raising  ourselves 
towards  that  ideal  of  perfection  which  has  been  graciously  presented  to  us  in  the 
"  well-beloved  Son  of  God,"  are  the  relations  of  the  Divine  Nature  to  our  own 
felt  to  be  more  intimate.  And  it  is  from  the  consciousness  of  our  relation  to 
God,  as  His  creatures,  as  His  children,  and  as  independent  but  responsible  fel- 
low-workers with  Him  in  accomplishing  His  great  purposes,  that  all  those  Ideas 
and  Sentiments  arise,  which  are  designated  as  Religious,  and  which  constitute 
that  most  exalted  portion  of  our  nature,  of  whose  continued  existence  and  yet 
higher  elevation  we  have  the  fullest  assurance,  both  in  the  depths  of  our  own 
Conciousness,  and  in  the  promises  of  Revelation. 

617.  It  has  been  usually  considered  by  Moralists  and  Theologians,  that  Con- 
science, or  the  Moral  Sense,  is  an  autocratic  faculty,  which  unmistakeably  dictates 
what  is  right  in  each  individual  case,  and  which  should  consequently  be  unhesi- 
tatingly obeyed  as  the  supreme  and  unerring  guide.  Now  this  view  of  the  case 
is  attended  with  practical  difficulties,  which  make  it  surprising  that  it  can  ever 
have  been  entertained.  For  it  must  be  obvious  to  every  one  who  carefully  consi- 
ders the  matter,  that  whilst  a  notion  of  right  and  wrong,  attaching  itself  to  cer- 
tain actions,  is  as  much  a  part  of  the  moral  nature  of  every  individual,  as  the 
feeling  of  pleasure  or  pain  attaching  itself  to  certain  states  of  consciousness  is  of 
his  sensational  nature,  yet  the  determination  of  what  is  right  and  what  is  wrong, 
is  a  matter  in  great  degree  dependent  upon  education,  habits  of  thought,  conven- 
tional associations,  &c.;  so  that  the  moral  standard  of  no  two  men  shall  be  pre- 
cisely alike,  and  the  moral  standards  of  men  brought  up  under  entirely-different 
circumstances  shall  be  of  the  most  opposite  nature.1  So,  whilst  the  notion  of  a 
God  sustaining  any  direct  relation  to  us,  involves  the  notion  of  Duty,  which 
attaches  itself  to  all  actions  with  which  He  can  be  considered  as  having  any  con- 
cern, the  dictates  of  this  sense  will  vary  with  the  ideas  entertained  respecting  the 
character  and  requirements  of  the  Deity ;  and  actions  may  be  sincerely  regarded 
as  an  acceptable  sacrifice  by  one  class  of  religionists,  which  are  loathed  as  barba- 
rous and  detestable  by  another.  Moreover,  in  what  have  been  designated  as 
'  cases  of  conscience/  the  most  enlightened  Moralist  may  have  a  difficulty  in  de- 
ciding what  is  the  right  course  of  action,  simply  because  the  i moral  sense'  finds 
so  much  to  approve  on  both  sides,  that  it  cannot  assign  a  preponderance  to  either. 
And  the  same  difficulty  attends  the  determination  of  religious  Duty,  in  many  pe- 
culiar contingencies  j  each  of  two  or  more  possible  modes  of  action  being  recom- 
mended by  its  conformity  to  the  Divine  law  on  certain  points,  whilst  it  seems 
opposed  to  it  on  others.  Thus,  individuals  in  whose  characters  the  love  of  truth 

1  Without  having  recourse  to  the  strange  estimates  of  right  and  wrong  which  prevail 
amongst  Savage  nations,  for  an  illustration  of  this  position,  it  may  be  sufficient  to  compare 
tfie  diiferent  views  conscientiously  entertained  on  the  question  of  Slavery,  by  high-mindod, 
estimable,  and  Christian  men  and  women  in  different  parts  of  the  American  Union. 


OF    IDEATIONAL    CONSCIOUSNESS.  565 

and  of  justice  and  the  benevolent  affections  are  the  prominent  features,  and  who 
would  shrink  with  horror  from  any  violation  of  these  principles  of  action  for  any 
selfish  purpose  whatever,  are  sorely  perplexed  when  they  are  brought  into  colli- 
sion with  each  other;  a  strong  motive  to  tell  a  falsehood  (for  example)  being  pre- 
sented by  the  desire  to  protect  a,  defenceless  fellow-creature  from  unmerited 
oppression  or  death.1 

618.  If,  then,  neither  the  Moral  sense  nor  the  sense  of  Religious  Duty  affords 
a  clear  and  unvarying  rule  of  action  in  each  individual  case,  it  is  evident  that  the 
determination  of  what  is  right  and  wrong  must  be  a  matter  of  judgment;  the  rule 
of  Moral  action  being  based  on  a.  comparison  of  the  relative  nobility  of  the  mo- 
tives which  impel  us  to  either  course,  and  being  decided  by  the  preference  which 
is  accorded  to  one  motive  or  combination  of  motives  above  another.2  If  it  be 
asked,  how  are  the  relative  values  of  these  motives  to  be  decided,  the  answer  must 
be  sought  in  the  moral  consciousness  of  Mankind  in  general,  which  is  found  to  be 
more  and  more  accordant  in  this  respect,  the  more  faithfully  it  is  interpreted,  the 
more  habitually  it  is  acted-on,  and  the  more  the  whole  intelligence  is  expanded 
and  enlightened.  It  is  this  tendency  towards  universal  agreement,  which  shows 
that  there  is  really  as  good  a  foundation  for  Moral  science  in  the  psychical  nature 
of  Man,  as  there  is  for  that  of  Music  in  the  pleasure  which  he  derives  from  cer- 
tain combinations  and  successions  of  sounds.  So,  again,  the  more  elevated  are 
the  religious  ideas  of  Mankind  in  regard  to  the  character  and  will  of  the  Deity, 
the  more  do  they  approach  to  a  general  accordance  in  regard  to  what  constitutes 
Religious  Duty  •  and  the  complete  coincidence  which  exists  between  the  dictates 
of  the  Christian  law  and  the  highest  principles  of  pure  Morality,  prevents  one  set 
of  motives  from  ever  coming  into  antagonism  with  the  other.  The  Conscience  of 
the  religious  man,  indeed,  may  be  said  to  be  the  resultant  of  the  combination  of 
his  Moral  sense  with  the  idea  of  Duty  which  arises  out  of  his  sense  of  relation 
to  the  Deity.  With  the  former  are  closely  associated  all  those  emotions  and  pro- 
pensities, which  render  him  considerate  of  the  welfare  of  his  fellow-men,  as  of 
his  own ;  and  with  the  notion  of  duty  to  God  are  closely  united  the  desire  of  His 
favour,  the  fear  of  His  displeasure,  the  aspiration  after  His  perfection,  all  which 
act  like  other  motives  in  deciding  the  Will.  Their  relative  force  on  any  occasion, 
as  compared  with  that  of  the  lower  propensities  and  sensual  desires,  greatly  de- 
pends on  the  degree  in  which  they  are  habitually  brought  to  influence  the  mind  j 
and  it  is  in  its  power  of  fixing  its  contemplation  on  those  higher  considerations 
which  ought  to  be  paramount  to  all  others,  and  of  withdrawing  it  from  the  lower, 
that  the  Will  has  the  chief  influence  in  the  direction  of  the  conduct  according  to 
the  dictates  of  Virtue. 

1  Thus  if  a  man,  who  might  be  urged  to  conceal  a  fugitive  slave  near  the  Canadian  fron- 
tier, were  to  refuse  to  do  so  merely  on  the  fear  of  unpleasant  consequences  to  himself,  he 
would  be  justly  branded  with  the  character  of  a  cold-hearted  coward;  but  if  his  refusal 
should  proceed  from  the  conviction  that  the  Divine  Law  requires  the  preference  of  rigid 
truthfulness  over  every  other  motive,  and  that,  by  concealing  the  suppliant,  he  should  be 
forced  into  a  violation  of  that  law,  he  cannot  be  blamed  even  by  those  who  believe  that  the 
law  of  compassion  written  upon  our  hearts  is  at  least  equally  imperative. — Similar  diffi- 
culties beset  the  upholders  of  the  non-resistance  creed,  which  teaches  that  love  is  the  all- 
powerful  principle  in  the  moral  world,  and  that  it  should  entirely  supersede  all  those 
impulses  of  our  nature  which  lead  us  to  oppose  force  to  force,  and  to  resist  an  unjust  and 
unprovoked  assault.  Here,  again,  we  might  readily  understand  and  sympathise-with 
those,  who  consider  that  the  fear  of  personal  suffering  does  not  warrant  our  doing  a  severe 
injury  to  another  in  warding-off  a  threatened  attack;  but  when  the  question  comes  to  be, 
not  of  self-defence,  but  of  protection  to  others  who  are  helpless  dependents  upon  our  suc- 
cour, and  who  are  bound  to  us  by  the  closest  ties  of  natural  affection,  we  feel  that  trie 
comparative  nobility  of  the  latter  motive  warrants  actions  which  our  individual  peril  might 
scarcely  justify. 

4  This  view  of  the  nature  of  Conscience  will  be  found  more  fully  developed  in  the  "  Pros- 
pective Review,"  for  November,  1845,  pp.  587-9. — "Every  moral  judgment,"  it  is  well- 
remarked  by  the  reviewer,  "is  relative ;  and  involves  a  comparison  of  (at  least)  two  terms. 
When  we  praise  what  has  been  done,  it  is  with  the  coexistent  conception  of  something  dst' 


FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

619.  Of  the  Emotional  Cbnsciomness. —  Although,  as  we  have  seen  (§§  602, 
609),  there  are  various  forms  of  Emotional  Sensibility  which  are  directly  called 
into  activity  by  sense-perceptions,  yet  those  Emotional  states  of  Mind,  which 
directly  or  indirectly  determine  a  great  part  of  our  conduct,  belong  to  the  level 
of  the  Ideational  consciousness  ;  being,  in  fact,  the  result  of  the  attachment  of 
the  feelings  of  pleasure  and  pain,  and  of  other  forms  of  emotional  sensibility,  to 
certain  classes  of  ideas.  Thus  the  Cerebrum  and  the  Sensory  Ganglia  would 
seem  to  act  jointly  in  their  production;  for  whilst  the  Cerebral  Hemispheres  fur- 
nish the  ideational  part  of  the  material,  the  Sensory  Ganglia  not  only  give  us 
the  consciousness  of  their  result,  but  invest  that  result  with  the  peculiar  feeling 
which  renders  it  capable  of  actively  influencing  our  conduct  as  a  motive  power. 
This  we  see  most  clearly,  when  the  Emotional  state  takes  the  form  of  a  true 
desire  ;  for  when  this  is  felt,  even  as  regards  the  gratification  of  a  bodily  appe- 
tite, it  involves  the  existence  of  an  idea  of  the  object  of  desire ;  but  it  is  only 
when  this  idea  is  associated  with  the  contemplation  of  enjoyment  in  the  act  to 
which  it  relates,  or  of  discomfort  in  the  abstinence  from  that  act,  that  it  becomes 
an  impelling  force  towards  the  performance  of  it. — All  the  higher  forms  of  Emo- 
tional consciousness  may  be  decomposed  (as  it  seems  to  the  Author)  in  a  similar 
manner.  Thus,  Benevolence  is  the  pleasurable  contemplation  of  the  happiness 
or  welfare  of  others,  and  shows  itself  alike  in  the  habitual  entertainment  of  the 
abstract  or  general  idea,  and  in  the  direction  of  the  conduct  with  a  view  to  pro- 
mote this  result  in  any  particular  instance  on  which  the  benevolent  desire  may  be 
fixed.  So  there  is  a  positive  pleasure,  in  some  ill-constituted  minds,  in  the  con- 
templation of  the  wwhappiness  of  others ;  and  this  we  designate  as  Malevolence. 
Again,  the  Combativeness  of  Phrenologists  is  nothing  else  than  the  pleasurable 
idea  of  setting  one's  self  in  antagonism  with  others;  which  may  manifest  itself 
either  physically  or  psychically,  according  to  the  temperament  of  the  individual.1 
So,  Pride  (or  self-esteem)  consists  in  the  pleasurable  contemplation  of  our  own 
superior  excellencies;  whilst  the  essence  of  Vanity  (or  love  of  approbation)  lies 
in  the  pleasurable  idea  of  the  applause  of  others.  Again,  in  Conscientiousness 
we  have  the  love  of  right,  that  is,  the  association  of  pleasure  with  the  idea  of 

that  might  have  been  done ;  and  -when  we  resolve  on  a  course  as  right,  it  is  to  the  exclusion 
of  some  other  that  is  wrong."  This  is  why  we  cannot  attach  any  moral  character  to  the 
actions  of  animals  that  are  performed  under  the  direction  of  a  blind,  undesigning  instinct, 
leaving  them  no  choice  between  one  course  and  another;  nor  to  those  which  are  executed 
by  human  beings,  even  when  possessed  of  their  full  intelligence,  under  the  domination  of 
impulses  which  they  have  it  not  in  their  power  to  restrain  ;  nor,  again,  to  those  performed 
by  individuals  whose  moral  sense  has  either  been  never  awakened,  or  has  been  so  com- 
pletely misdirected  by  early  education,  that  their  standard  of  right  and  wrong  is  altogether 
opposite  to  that  which  the  enlightened  conscience  of  mankind  agrees  in  adopting.  But, 
although  there  are  doubtless  many  cases  in  which  criminal  actions  are  committed  under 
the  impulse  of  passions  (such  as  anger,  lust,  &c.)  which  the  individual  has  not  at  the  mo- 
ment the  power  to  control,  and  although  he  must  be  absolved  from  moral  responsibility 
quoad  the  immediate  motives  of  those  particular  actions,  yet  these  motives  too  frequently 
derive  all  their  force  from  the  habit  of  yielding  to  their  promptings  in  lesser  matters, 
which  gradually  gives  them  a  dominance,  such  as  the  Will  (weakened  by  want  of  exercise 
in  the  habit  of  self-restraint)  is  unable  to  resist.  Hence  the  criminal  action  is  to  be  re- 
garded as  but  the  expression  of  a  long  previous  course  of  criminal  thought,  for  which,  in 
so  far  as  he  could  have  otherwise  directed  it,  the  individual  may  legitimately  be  held 
responsible. 

1  There  are  individuals  who  never  manifest  the  least  degree  of  physical  combativeness, 
who  yet  show  a  remarkable  love  of  opposition  in  all  their  psychical  relations  with  others. 
That  objections  will  be  raised  by  such  persons  to  any  plan  that  may  be  proposed,  we  can 
always  feel  sure,  though  we  may  not  have  the  remotest  idea  as  to  what  the  objection  may 
be  in  each  particular  case.  Persons  in  whom  this  tendency  exists  in  a  less  prominent 
degree,  are  apt  to  see  objections  and  difficulties.^^/,  although  their  good  sense  may  sub- 
sequently lead  them  to  consider  these  as  of  less  account,  or  to  be  outweighed  by  the  ad- 
vantages of  the  scheme.  Such  was  the  case  with  the  late  Sir  Robert  Peel.  On  the  other 
hand,  those  who  are  spoken-of  as  of  sanguine  temperament,  are  apt  to  lose  sight  of  the 
intervening  difficulties,  in  the  pleasurable  anticipation  of  the  result. 


OF    THE    EMOTIONAL    CONSCIOUSNESS.  567 

right ;  Veneration  may  be  defined  as  the  pleasurable  contemplation  of  rank  or 
perfections  superior  to  our  own  ;  and  the  source  of  Ambition,  which  is  in  some 
degree  the  antagonistic  tendency,  lies  in  the  pleasurable  idea  of  self-exaltation. 
In  like  manner,  Hope  is  the  pleasurable  contemplation  of  future  enjoyment ; 
Fear  is  the  painful  contemplation  of  future  evil ;  and  Cautiousness  is  the  combi- 
nation of  the  desire  to  avoid  anticipated  pain,  with  the  pleasurable  contemplation 
(an  extremely  strong  feeling  in  many  individuals)  of  precautions  adapted  to  ward 
it  off.  —  The  same  view  may  be  applied  to  the  love  of  Order,  of  Possessions,  of 
Country,  of  Wit,  of  Humour,  &c.,  and  to  many  conditions  usually  considered  as 
purely  Intellectual.  And,  in  fact,  the  association  of  any  kind  of  that  Emotional 
sensibility  (§  602)  of  which  pleasure  and  pain  afford  the  simplest  type,  with  any 
idea,  or  class  of  ideas,  gives  to  it  an  Emotional  character;  so  that  Emotional 
states  are  not  by  any  means  limited  within  the  categories  under  which  Psycholo- 
gists have  attempted  to  range  them ;  these  being,  for  the  most  part,  generic  terms, 
which  comprehend  certain  groups  of  ideas  bearing  more  or  less  similarity  to  each 
other,  but  not  by  any  means  including  all  possible  combinations.1 

620.  By  those  who  regard  the  Propensities,  Moral  Feelings,  &c.,  as  simple 
states  of  mind,  it  is  usually  said  that  their  indulgence  or  exercise  is  attended 
with  pleasure,  and  the  restraint  of  them  with  pain.     But,  if  the  view  here  taken 
be  correct,  it  is  the  very  co-existence  of  pleasurable  or  painful  feelings  with  the 
idea  of  a  given  object,  that  causes  desire  or  aversion  as  regards  that  object;  since 
the  mind  instinctively  pursues  what  is  pleasurable,  and  avoids  what  is  painful. 
And  thus,  according  to  the  readiness  with  which  these  different  classes  of  ideas 
are  excited  in  different  minds  (partly  depending  upon  original  constitution,  and 
partly  upon  the  habitual  direction  of  the  thoughts),  and  to  the  respective  degrees 
in  which  they  respectively  call-forth  the  different  kinds  of  Emotional  sensibility 
(as  to  which  there  is  obviously  an  inherent  difference  amongst  individuals,  analo- 
gous to  that  which  exists  with  regard  to  the  feelings  of  pleasure  or  pain  excited 
by  external  sensations,  sights,  sounds,  tastes,  odours,  or  contacts),  will  be  the 
disposition  of  the  mind  to  entertain  them,  the  frequency  with  which  they  will  be 
brought  before  the  mental  view,  and  the  influence  which  they  will  exert  in  the 
determination  of  our  conduct 

621.  The  influence  of  Emotional  conditions,  when  strongly  excited,  in  directly 
producing  involuntary  movements,  is  readily  explained  on  the  idea  that  the  Sen- 
sory Ganglia  are  the  seat  of  all  consciousness,  and  the  Cranio-Spinal  axis  the  real 
source  of  all  movement.     For  there  is  no  more  difficulty  in  understanding,  that 
the  excitement  of  peculiar  states  of  consciousness  in  the  Sensorial  centres  through 
the  instrumentality  of  the  Cerebrum,  should  give  rise  to  automatic  movements, 
than  that  such  movements  should  follow  similar  states  of  consciousness,  when 
excited  by  impressions  made  upon  the  organs  of  vision,  hearing,  &c.     And  the 
correspondence  is  seen  to  be  very  close,  when  the  idea  (as  is  doubtless  the  case 
in  some  instances)  is  very  nearly  akin  to  the  sensation.     Thus,  the  laughter  ex- 
cited by  the  act  of  tickling,  is  a  purely  consensual  movement  (§  538) ;  but,  in  a 
very  *  ticklish '  person,  the  mere  idea  of  tickling,  suggested  by  pointing  a  finger 
at  him,  is  sufficient  to  provoke  it.     So,  again,  as  Laughter  may  be  excited  by  odd 
sights  or  sounds  which  do  not  in  themselves  excite  any  ideational  state,  but  which 
act  at  once  upon  the  '  sense  of  the  ludicrous,'  the  same  action  may  be  called-furth 
by  the  vivid  recollection  of  these  occurrences,  which  being  attended  with  a  state 

1  The  truth  of  this  statement  must  be  apparent  to  all  who  are  familiar  with  the  mani- 
festations of  Eccentricity  and  Insanity;  for  we  frequently  see  pleasurable  feelings  asso- 
ciating themselves  with  ideas,  which  to  ordinary  minds  appear  indifferent,  or  are  even 
regarded  with  pain ;  and  thus  are  engendered  motives,  which  exert  a  most  powerful  in- 
fluence over  the  conduct,  and  which,  if  not  kept  in  restraint  by  the  Will,  render  the  whole 
being  their  slave. — It  may  be  also  remarked,  in  this  place,  that  the  impossibility  of  class- 
ing all  the  Emotional  states  of  mind  under  a  limited  number  of  categories,  constitutes  a 
most  serious  and  fundamental  objection  to  any  system,  which  professes  to  mark  out  in  tht» 
Cerebrum  distinct  seats  for  the  Animal  Propensities,  Moral  Feelings,  &c. 


568  FUNCTIONS   OF    THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

of  the  sensorium  corresponding  to  that  originally  produced  by  the  sensation, 
gives-rise  to  the  same  involuntary  cachinnation.     But  Laughter  may  also  be  ex- 
cited by  ideas  that  are  much  more  removed  from  actual  sensations,  as,  for  exam- 
ple, by  those  unexpected  combinations  of  ideas  of  a  purely  intellectual  nature, 
which  we  designate  as  '  witty ;'  and  here,  too,  we  may  recognize  the  very  same 
modus  operandi.     For  the  mere  sound  or  sight  of  the  words  excites  no  feeling 
of  the  ludicrous;  the  sensation  must  develope  an  ideational change  ;  and  it  is  the 
latter  alone,  which,  reacting  downwards  upon  the  Sensorium,  and  there  becoming 
associated  with  the  Emotional  sensibility,  exercise  'the  impulse  to  laugh.     The 
game  might  be  shown  to  be  the  case  with  regard  to  the  act  of  Crying ;  which 
may  be  either  purely  consensual,  being  excited  by  painful  sensations;  or  may  be 
induced  by  the  vivid  recollection  of  past  or  the  anticipation  of  future  sensations; 
or  may  be  excited  by  ideas  which  have  no  direct  relation  to  sensational  states. 
Again,  the  movements  which  take  place  under  the  violent  excitement  of  the  pas- 
sion of  Anger,  are  of  the  same  involuntary  character;  being  directly  prompted 
by  feelings,  which  may  be  called-up  either  by  external  sensations,  or  by  internal 
ideas  that  have  a  like  power  of  exciting  them.     Thus  the  passionate  man  who 
receives  a  blow,  instinctively  makes  another  blow  in  the  direction  from  which  it 
seemed  to  him  to  come,  without  any  thought  of  whether  the  blow  was  accidental 
or  intentional ;  and  the  idea  of  an  insult,  which  is  a  source  of  mental  disturbance, 
may  excite  the  very  same  movement,  although  no  bodily  suffering  had  been  expe- 
rienced.    In  states  of  excessive  Sexual  excitement,  again,  the  desire,  which  arises 
out  of  the  idea  of  the  object  (§  619),  produces  involuntary  movements  corre- 
sponding to  those  which  are  ordinarily  linked-on  to  the  actual  sensations  alone. 
There  are  many  of  the  movements  of  Expression,  which  are  referable  in  like 
manner  to  states  of  consciousness,  whether  pleasurable  or  painful,  which  may 
arise  from  ideational  as  well  as  from  sensational  conditions.     Thus,  as  we  have 
seen,  the  Cheerful  aspect  of  some  individuals  is  due  to  a  sense  of  general  physical 
well-being,  and  is  altogether  discomposed  by  anything  which  disturbs  this ;  whilst 
in  others,  it  may  proceed  from  a  happy  frame  of  mind  (which  may  be  partly  the 
result  of  original  constitution,  and  partly  of  habitual  self-direction),  disposing 
them  to  take  the  cheerful  view  of  everything  that  affects  themselves  or  others, 
notwithstanding  (it  may  be)  great  bodily  discomfort.     And  the  reverse  aspect  of 
Gloom  may  in  like  manner  proceed  alike  from  bodily  or  from  mental  uneasiness. 
— All  these  facts  point,  therefore,  to  the  conclusion,  that  whether  the  elemen- 
tary states  of  Emotional  sensibility  associate  themselves  with  Sensations,  with 
Perceptions,  or  with  Ideas,  they  are  simple  modes  of  consciousness,  the  organic 
seat  of  which  must  be  in  the  Sensorial  centres ;  and  this  corresponds  well  with 
the  character  of  the  purely  Emotional  movements,  which,  as  we  have  seen,  are 
closely  allied  to  the  Sensori-motor,  in  the  directness  with  which  they  respond  to 
the  stimuli  that  excite  them. 

622.  That  the  Emotional  and  Volitional  movements  differ  as  to  their  primal 
sources,  is  obvious,  not  merely  from  the  fact  that  they  are  frequently  in  antago- 
nism with  each  other, — the  Will  endeavouring  to  restrain  the  Emotional  im- 
pulse, and  either  succeeding  in  doing  so,  or  being  vanquished  by  the  superior 
force  of  the  latter, — but  also  from  the  curious  fact,  which  Pathological  observa- 
tion has  brought  to  light,  that  muscles  which  will  still  act  in  obedience  to  Emo- 
tional impulses,  may  be  paralysed  to  Volitional,  and  vice  versa.  Thus  for  example, 
the  arm  of  a  man  affected  with  hemiplegia,  which  no  effort  of  his  will  could  move, 
has  been  seen  to  be  violently  jerked  under  the  influence  of  the  mental  agitation 
consequent  upon  the  sight  of  a  friend.  And  in  the  case  of  softening  of  the  Spinal 
Cord  already  referred-to  (§  503  note),  the  choreic  movements,  which  were  brought- 
on  by  the  mere  approach  of  any  one  to  the  patient's  bed,  and  still  more  strongly 
by  putting  a  question  to  him,  were  most  violent  in  the  lower  limbs,  over  which 
he  had  not  the  least  voluntary  power.  It  is  in  the  different  forms  of  paralysis  of 
the  Facial  nerve  however,  which  is  the  one  most  peculiarly  subservient  to  the 


OF    THE     EMOTIONAL    CONSCIOUSNESS.  569 

movements  of  Expression,  that  we  have  the  best  evidence  of  this  distinctness. 
For  it  sometimes  happens  that  the  muscles  supplied  by  this  nerve  are  paralysed 
so  far  as  regards  the  Will,  and  yet  are  still  aifected  by  Emotional  states  of  mind 
and  take  their  usual  part  in  the  automatic  actions  of  Respiration,  &c.,  retaining 
also  their  usual  tension,  so  that  no  distortion  is  apparent  unless  Voluntary  move- 
ments be  attempted  :  thus,  to  select  an  action  which  may  be  performed  either 
consensually,  emotionally,  or  voluntarily,  a  patient  affected  with  this  form  of 
paralysis  cannot  close  the  eyelid  by  an  act  of  his  will,  although  he  winks  when  he 
feels  the  uneasy  sensation  that  excites  the  action,  and  shuts  the  lids  when  the 
sudden  approach  of  an  object  to  the  eye  excites  the  fear  of  injury  to  that  organ. 
On  the  other  hand,  the  paralysed  condition  may  exist  in  regard  to  the  automatic 
and  emotional  actions  only,  so  that  the  muscles  lose  their  tension,  the  mouth  is 
drawn  to  one  side,  the  movements  of  expression  are  not  performed,  and  there  is 
no  involuntary  winking:  yet  the  Will  may  still  exert  its  accustomed  control,  and 
may  produce  that  closure  of  the  lids  which  does  not  take  place  in  respondence 
to  any  other  impulse.1 — It  has  been  inferred  by  Dr.  M.  Hall,2  from  cases  of  this 
kind,  that  the  Emotional  actions  are  among  those  which  are  performed  by  his 
*  true  spinal '  system  of  nerves,  as  distinct  from  the  sensori-volitional,  and  that 
they  therefore  fall  under  the  general  category  of  excito-motor  actions.  But  it  is 
obvious  that  they  differ  from  these  in  their  dependence,  not  merely  upon  sensa- 
tions, but  also  upon  higher  states  of  mind ;  and  there  is  no  proof  whatever,  that 
the  same  nerve-fibres  do  not  serve  for  the  conduction  of  the  motor  impulses  pro- 
ceeding from  the  two  different  mental  sources,  Volition  and  Emotion,  as  we  have 
seen  that  they  probably  do  for  the  volitional  and  automatic  impulses  (§  550). 3 

623.  The  Emotions  are  concerned  in  Man,  however,  in  many  actions,  which 
are  in  themselves  strictly  voluntary.  Unless  they  be  so  strongly  excited  as  to 
get  the  better  of  the  Will,  they  do  not  operate  downwards  upon  the  Automatic 
centres,  but  upwards  upon  the  Cerebral ;  supplying  the  motives  by  which  the 
course  of  thought  and  of  action  is  habitually  determined  (§  676).  Thus,  of  two 
individuals,  with  differently-constituted  minds,  one  shall  judge  of  everything 
through  the  medium  of  a  gloomy  and  morose  temper,  which,  like  a  darkened 
glass,  represents  to  his  judgment  the  whole  world  in  league  to  injure  him; 
and  his  determinations  being  all  based  upon  this  erroneous  view,  its  indications 
are  exhibited  in  his  actions  ;  which  are  themselves,  nevertheless,  of  an  entirely- 
voluntary  character.  On  the  other  hand,  a  person  of  a  cheerful,  benevolent 
disposition,  looks  at  the  world  around  as  through  a  Claude-Lorraine-glass,  seeing 
everything  in  its  brightest  and  sunniest  aspect ;  and  with  intellectual  faculties 
precisely  similar  to  those  of  the  former  individual,  he  will  come  to  opposite  con- 
clusions; because  the  materials  which  form  the  basis  of  his  judgment,  are 
submitted  to  it  in  a  very  different  condition.  Various  forms  of  Moral  Insanity 
exhibit  the  same  contrast,  in  a  yet  more  striking  light  (§  707).  We  not  unfre- 
quently  meet  with  individuals,  still  holding  their  place  in  society,  who  ar<3 
accustomed  to  act  so  much  upon  impulse,  and  to  be  so  little  guided  by  reason,  a* 
to  be  scarcely  regarded  as  sane;  and  a  very  little  exaggeration  of  such  a  ton- 
dency  causes  the  actions  to  be  so  injurious  to  the  individual  himself,  or  to  thus! 
around  him,  that  restraint  is  required,  although  the  intellect  is  in  no  way  disoi- 
dered,  nor  are  any  of  the  feelings  perverted.  Not  unfrequently  we  may  observe 

1  See  the  detailed  accounts  of  such  cases  in  Sir  C.  Bell's  work  on  "  The  Nervous  System  of 
the  Human  Body;"  also  "Brit,  and  For.  Med.  Rev.,"  vol.  iv.  p.  500,  and  vol.  xiii.  p.  551  ' 

a  "  Memoirs  on  the  Nervous  System,"  1837,  pp.  94.  et  seq. 

3  In  the  earlier  editions  of  this  Treatise,  the  Author  maintained,  upon  the  principles 
advocated  by  Dr.  M.  Hall,  that  there  must  be  distinct  centres  and  conducting  fibres  for 
Volitional,  Emotional,  and  Reflex  movements.  Having  since  arrived  at  what  he  believes 
to  be  a  much  simpler  explanation  of  the  phenomena,  and  one  more  in  accordance  with  the 
facts  of  the  case,  he  has  not  hesitated  to  make  known  the  change  in  his  convictions,  and 
would  hope  that  he  may  induce  those  who  may  have  adopted  his  previous  opinions,  t« 
reconsider  the  subject  under  the  aspect  in  which  he  has  now  placed  it. 


570  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

similar  inconsistencies,  resulting  from  the  habitual  indulgence  of  one  particular 
feeling,  or  from  a  morbid  exaggeration  of  it.  The  mother  who,  through  weak- 
ness of  Will,  yields  to  her  instinctive  fondness  for  her  offspring,  in  allowing  it 
gratifications  which  she  knows  to  be  injurious  to  it,  is  placing  herself  below  the 
level  of  many  less  gifted  beings.  The  habit  of  yielding  to  a  natural  infirmity  of 
temper  often  leads  into  paroxysms  of  ungovernable  rage,  which  in  their  turn, 
pass  into  a  state  of  maniacal  excitement.  It  is  not  unfrequently  seen,  that  a 
delusion  of  the  intellect  (constituting  what  is  commonly  known  as  Monomania) 
has  in  reality  resulted  from  a  disordered  state  of  the  feelings,  which  have  repre- 
sented every  occurrence  in  a  wrong  light  to  the  mind  of  the  individual  (§  709). 
All  such  conditions  are  of  extreme  interest,  when  compared  with  those  which 
are  met-with  amongst  idiots,  and  animals  enjoying  a  much  lower  degree  of 
intelligence :  for  the  result  is  much  the  same,  in  whatever  way  the  balance 
between  the  feelings  and  the  judgment  (which  is  so  beautifully  adjusted  in  the 
well-ordered  mind  of  Man)  is  disturbed ;  whether  by  a  diminution  of  the  Vol- 
untary control,  or  by  an  undue  exaltation  of  the  Emotions  and  passions. 

624.  This  double  modus  operandi  of  the  Emotional  consciousness, — down 
wards  through  the  nerve-trunks  upon  the  Muscular  apparatus,  and  also  upon 
many  of  the  organic  functions  (CHAP,  xv.), — and  upwards  upon  those  Cerebral 
actions  which  give-rise  to  the  higher  states  of  Mental  consciousness, — affords  a 
satisfactory  explanation  of  a  fact  which  is  practically  familiar  to  most  observers 
of  Human  nature  j  namely,  that  violent  excitement  of  the  feelings  most  speedily 
subsides,  when  these  unrestrainedly  expend  themselves  (so  to  speak)  in  their 
natural  expressions.  Thus  it  may  be  commonly  noticed  that  those  who  are 
termed,  demonstrative  persons  are  less  firm  and  deep  in  their  attachments,  than 
those  who  manifest  their  feelings  less ;  for  without  any  real  insincerity  or  inten- 
tional fickleness,  the  strongly-excited  feelings  of  the  former  are  rapidly  calmed- 
down  by  the  expenditure  of  the  impulse  to  action  which  they  have  generated ; 
whilst  in  the  latter  the  very  same  feelings,  acting  internally,  acquire  a  permanent 
place  in  the  psychical  nature,  and  habitually  operate  as  motives  to  the  conduct. 
So,  again,  persons  who  are  l  quick-tempered,'  manifesting  great  irascibility  upon 
small  provocations,  real  or  supposed,  are  usually  soon  appeased,  and  soon  forget 
the  affront;  whilst  those  who  make  little  or  no  display  of  anger,  are  very  apt  to 
brood-over  and  cherish  their  feelings  of  indignation,  and  may  visit  them 
upon  the  unfortunate  object  of  them,  when  some  favourable  opportunity  happens 
to  occur,  long  after  he  had  supposed  that  the  occurrence  which  had  given  rise  to 
them  was  forgotten.  There  is  an  instinctive  restlessness,  or  tendency  to  general 
bodily  movement,  in  some  individuals,  when  they  are  suffering  under  emotional 
excitement  j  the  indulgence  of  which  appears  to  be  a  sort  of  safety-valve  for  the 
excess  of  nerve-force,  whilst  the  attempt  at  -ts  repression  is  attended  with  an 
increase  in  the  excitement.  Most  persons  are  conscious  of  the  difficulty  of 
sitting  still,  when  they  are  labouring  under  violent  agitation,  and  of  the  relief 
which  is  afforded  by  active  exercise ;  and  this  is  particularly  the  case  when  the 
movements  are  such  as  naturally  express  the  passion  that  is  excited.  Thus  the 
combative  propensities  of  the  Irish  peasant  commonly  evaporate  speedily  with 
the  free  play  of  the  shillelagh ;  many  irascible  persons  find  great  relief  in  a 
hearty  explosion  of  oaths,  others  in  a  violent  slamming  of  the  door,  and  others 
(whose  excitement  is  more  moderate  but  less  transient)  in  a  prolonged  fit  of 
grumbling.1  So,  again,  if  a  ludicrous  idea  be  suggested  to  our  consciousness, 

1  This  view  is  most  fully  confirmed  by  certain  phenomena  of  Insanity.  It  is  a  doctrine 
now  generally  received  among  practical  men,  that  paroxysms  of  violent  emotional  excite- 
ment are  much  more  likely  to  subside,  when  they  are  allowed  to  '  work  themselves  oif ' 
freely,  without  any  attempt  at  mechanical  restraint;  and  maniacal  patients  are  now 
placed,  in  all  well-managed  Asylums,  in  padded  rooms,  in  which  their  movements  can  do 
no  injury  to  themselves  or  others. — The  following  case  was  related  to  the  Author  by  his 
friend  Dr.  Howe,  of  Boston,  N.  E.,  the  instructor  of  Laura  Bridgman.  A  half-idiotic 
youth  in  th«  Lunatic  Asylum  of  that  place,  was  the  subject  (like  many  in  his  condition) 


OF    THE    EMOTIONAL     CONSCIOUSNESS.  571 

occasioning  an  impulse  to  laugh,  a  hearty  f  guffaw  '  generally  works-off  the  excite- 
ment, and  we  may  be  surprised  a  short  time  afterwards  that  such  an  absurdity  should 
have  provoked  our  risibility  ;  but  if  we  restrain  the  explosion,  the  idea  continues  to 
4  haunt'  us,  and  is  continually  perturbing  our  trains  of  thought  until  we  have  given 
free  vent  to  the  expression  of  it.  Again,  it  is  well  known  that  the  depressing  emo- 
tions are  often  worked-off  by  a  fit  of  crying  and  sobbing ;  and  the  f  relief  of  tears ' 
seems  manifestly  due  to  the  expenditure  of  the  pent-up  nerve-force,  in  the  produc- 
tion of  an  increased  secretion.  It  is  noticed  in  this  case,  too,  that  the  absence  of 
any  such  external  manifestations  of  the  depressing  emotions,  gives  them  a  much 
greater  influence  upon  the  course  of  thought,  and  upon  the  bodily  state  of  the 
individual.  Those  who  really  'die  of  grief/  are  not  those  who  are  loud  and 
vehement  in  their  lamentations,  for  their  sorrow  is  commonly  transient,  however 
vehement  and  sincere  while  it  lasts ;  but  they  are  those  who  have  either  designedly 
repressed  any  such  manifestations,  or  who  have  experienced  no  tendency  to  their 
display ;  and  their  deep-seated  sorrow  seems  to  exert  the  same  kind  of  anti-vital 
influence  upon  the  organic  functions,  that  is  exercised  more  violently  by  '  shock f 
producing  their  entire  cessation  without  any  structural  lesion.1 

625.  The  influence  of  Emotional  excitement  may  operate  upon  the  muscles, 
however,  not  only  in  giving-rise  to  movements  which  can  be  attributed  to  no 
other  source,  but  also  in  affecting  the  power  of  the  Will  over  the  muscular  sys- 
tem, by  intensifying  or  weakening  its  action.  For  there  can  be  no  doubt  that, 
under  the  strong  influence  of  one  class  of  feelings,  the  Will  can  effect  results  such 
as  the  individual  would  scarcely  even  attempt  in  his  calmer  moments  ;  whilst  the. 
influence  of  another  class  of  feelings  is  exercised  in  precisely  the  opposite  direction, 
weakening  or  even  paralysing  the  force  which  was  previously  in  full  activity.  But 
the  same  emotion  does  not  always  act  in  the  same  mode ;  thus,  the  fear  of  danger 
may  nerve  one  man  to  the  most  daring  and  vigorous  efforts  to  avert  it,  whilst 
another  is  rendered  powerless,  and  gives-way  to  unavailing  lamentations;  and 
the  ardent  anticipation  of  success  may  so  unsettle  the  determinative  energy  of  one 
aspirant,  as  to  prevent  him  from  attaining  his  object,  whilst  another  may  only  be 
sustained  by  it  in  the  toilsome  struggle  of  which  it  is  the  final  reward.  Now  in 
order  that  this  variety  may  be  explained,  and  the  modus  operandi  of  the  Emo- 
tions on  strictly  Volitional  actions  may  be  duly  comprehended,  we  must  here 
state  two  of  the  essential  conditions  of  the  latter;  one  of  which  is,  that  there 
should  be  not  merely  a  distinct  conception  of  the  purpose  to  be  obtained,  but  also 
a  belief  that  the  purpose  will  or  at  least  may  be  attained;  whilst  the  other  is, 
that  the  mental  energy  should  be  to  a  great  extent  withdrawn  from  other  objects, 

of  frequent  and  violent  paroxysms  of  anger;  and  with  the  view  of  moderating  these, 
it  was  suggested  that  he  should  be  kept  for  some  time  every  day  in  rather  fatiguing 
exercise.  Accordingly  he  was  employed  for  two  or  three  hours  daily  in  sawing  wood, 
to  which  task  he  made  no  objection  ;  and  the  paroxysms  of  rage  never  displayed  them- 
selves, except  on  Sundays,  when  his  employment  was  intermitted.  It  having  been  con- 
sidered, however,  that  it  was  better  for  him  to  spend  part  of  that  day  in  sawing  wood, 
than  to  be  irascible  during  the  whole  of  it,  his  occupation  was  continued  through  the 
whole  week,  when  he  became  completely  tamed-down.  and  never  gave  any  more  trouble 
by  his  passionate  displays. — This  case  appears  to  the  Author  a  most  valuable  confirmation 
of  the  doctrine  laid  down  in  the  text ;  which  is  one  whose  practical  bearings  are  most 
important. 

1  The  Author  once  heard  the  following  singular  case  of  this  kind : — One  of  two  sisters, 
orphans,  who  were  strongly  attached  to  each  other,  became  the  subject  of  consumption ; 
she  was  most  tenderly  nursed  by  her  sister  during  a  long  illness ;  but  on  her  death,  the 
latter,  instead  of  giving  way  to  grief  in  the  manner  that  might  have  been  anticipated, 
appeared  perfectly  unmoved,  and  acted  almost  as  if  nothing  had  happened.  About  a 
fortnight  after  her  sister's  death,  however,  she  was  found  dead  in  her  bed ;  yet  neither 
had  there  been  any  symptoms  during  life,  nor  was  there  any  post-mortem  appearance, 
which  in  the  least  degree  accounted  for  this  event, — of  which  no  explanation  seems  admis- 
sible, except  the  depressing  influence  of  her  pent-up  grief  upon  her  frame  generally, 
through  the  nervous  system. 


572  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

and  should  be  concentrated  upon  that  towards  which  the  Will  is  directed.  — It  is 
within  the  experience  of  every  one,  that  there  is  nothing  which  tends  so  much 
to  the  success  of  a  volitional  effort,  as  a  confident  expectation  of  its  success; 
whilst  nothing  is  so  likely  to  induce  failure,  as  the  apprehension  of  it.  Now,  in 
so  far  as  regards  this  mode  of  their  operation  alone,  the  tendency  of  the  cheerful 
or  joyous  emotions  being  to  suggest  and  keep-alive  the  favourable  anticipations, 
whilst  that  of  the  depressing  emotions  (of  almost  any  kind)  is  to  bring  before  the 
view  all  the  chances  of  failure,  the  former  will  increase  the  power  of  the  voli- 
tional effort,  and  the  latter  will  diminish  it.  And  they  exert  also  a  direct 
influence  on  the  physical  powers,  through  the  organs  of  circulation  and  respira- 
tion ;  the  heart's  impulses  being  more  vigorous  and  regular,  and  the  aeration  of 
the  blood  being  more  effectually  performed,  in  the  former  of  these  conditions 
than  in  the  latter. — But  an  altogether  contrary  effect  may  be  produced  by  the 
operation  of  these  two  classes  of  Emotions  through  the  second  of  the  above  chan- 
nels. For  the  more  completely  the  mental  energy  can  be  brought  into  one  focus, 
and  all  distracting  objects  excluded,  the  more  powerful  will  be  the  volitional 
effort ;  and  the  effect  of  emotional  excitement  will  thus  in  great  degree  depend 
upon  the  intellectual  constitution  which  the  individual  may  happen  to  possess. 
For  if  he  have  a  considerable  power  of  abstraction  and  concentration,  and  a  full 
conviction  that  he  has  selected  the  best  or  the  only  means  to  accomplish  his  end, 
the  intensest  fear  of  the  consequences  of  failure  will  only  increase  the  force  of 
the  motive  which  prompts  the  effort ;  and  the  whole  energy  of  which  his  nature 
is  capable,  will  display  itself  in  the  attempt.  In  a  man  of  this  temperament,  the 
most  joyous  anticipation  of  success  will  produce  no  abatement  of  his  efforts,  no 
distraction  of  his  attention,  but  will  rather  tend  to  keep  him  steady  to  his  pur- 
pose until  it  shall  have  been  accomplished;  and  then  only  does  he  dare  to  aban- 
don himself  to  the  current  of  ideas  which  rolls-in  upon  his  consciousness,  so  soon 
as  his  attention  is  free  to  entertain  them.  But  the  mind  which  is  deficient  in 
the  power  of  concentrativeness,  is  lamentably  deranged  by  any  kind  of  emotional 
excitement,  in  the  performance  of  any  volitional  effort.  For  the  fear  of  failure 
is  constantly  suggesting  to  him  new  distresses,  weakens  his  confidence  in  any 
method  suggested  for  his  action,  and  makes  him  direct  his  attention,  not  to  some 
fixed  plan  as  the  best  or  the  only  feasible  one,  but  to  any  and  every  means  that 
may  present  a  chance  of  success,  or  may  even  serve  to  avert  his  thoughts  from 
the  dreaded  catastrophe;  whilst,  on  the  other  hand,  the  joyous  anticipation  of 
success  leads  him  to  allow  his  thoughts  to  direct  themselves  towards  all  its  agree- 
able consequences,  instead  of  fixing  his  intellectual  and  volitional  energy  upon 
the  means  by  which  success  is  to  be  attained. 

626.  If  this  be  the  true  solution  of  the  mode  in  which  the  Emotions  chiefly 
affect  the  exercise  of  our  Volitional  powers,  we  should  expect  that  similar  effects 
might  be  induced,  without  any  Emotional  excitement,  by  means  which  affect  the 
Intellectual  consciousness  alone;  and  that  thus  an  action  otherwise  impossible  to 
the  individual  may  be  performed  by  him,  if  (1)  his  mind  be  possessed  with  a 
full  assurance  of  success,  and  (2)  if  his  entire  motor  energy  be  concentrated  in 
the  single  exertion  ;  whilst,  on  the  other  hand,  an  action  which  can  be  ordinarily 
performed  with  the  greatest  facility  may  become  absolutely  impossible  to  him, 
if  (1)  his  mind  be  entirely  possessed  with  the  idea  of  its  impossibility,  or  even 
V2)  if,  while  his  judgment  entertains  doubts  of  success,  his  attention   be  dis- 
tracted by  a  -variety  of  objects,  so  that  he  cannot  bring  it  to  bear  upon  the  one 
effort  which  may  alone  be  needed. — Now  experience  shows  that  such  is  really 
the  case ;   but  as  this  experience  is  the  most  remarkable  in  regard  to  certain 
states  of  the  mind  in  which  these  two  modes  of  operation  may  be  worked  in 
combination,    it   will   be   sufficient   to   refer   to   them   for   the    demonstration 
(§§  666,  672). 

627.  Succession  of  Psychical  States. — The  Mind,  when  not  engrossed  in  Sen- 
sational or  Perceptive  acts,  is  incessantly  occupied  in  thinking  ;  its  whole  inner 


SUCCESSION  OF  PSYCHICAL  STATES.        573 

life  being  a  succession  of  Ideas  and  Emotions,  only  suspended  by  Sleep  and 
Death,  or  interrupted  by  the  concentration  of  its  attention  on  impressions  newly 
received  from  external  objects.  Now  whatever  difference  of  opinion  there  may 
be,  in  regard  to  the  degree  in  which  the  ordinary  laws  of  Causation  are  applicable 
to  Mental  phenomena  (in  other  words,  as  to  how  far  each  state  of  consciousness 
may  be  considered  as  determined  by  its  antecedents),  all  are  agreed  that,  in  each 
individual,  there  are  certain  uniformities  of  mental  action,  which  constitute  what 
is  termed  his  Character;  and  that  these  uniformities  are  in  part  the  result  of  his 
congenital  constitution,  and  in  part  of  the  circumstances  in  which  he  may  have 
been  placed ;  both  of  which  sets  of  influences  concur  to  establish  certain  tendencies 
to  thought,  which  manifest  themselves  in  his  ordinary  course  of  action,  as  well  as 
in  the  more  express  products  of  his  Mental  labour. — Thus  we  find  the  Intellectual 
character  of  each  individual  to  consist  in  the  predominance  of  certain  '  Intellectual 
Faculties/  which,  as  we  shall  hereafter  see,  are  only  designations  for  particular 
modes  of  Intellectual  activity ;  and  hence  we  can  predicate,  to  a  certain  extent, 
the  nature  of  the  result  at  which  his  Mind  will  arrive  by  its  exercise  upon  a  given 
subject.  So,  again,  his  Moral  character  will  depend  upon  the  combination  which 
may  exist  in  his  individual  nature,  of  those  Emotional  tendencies,  which  not 
merely  furnish  a  large  share  of  the  governing  motives  of  his  actions,  but  which 
also  contribute  in  a  very  important  measure  to  the  direction  of  his  thoughts,  in 
virtue  of  that  law  of  our  nature  which  leads  us  to  dwell  on  those  subjects  where- 
with pleasurable  feelings  are  associated,  and  to  withdraw  our  contemplation  from 
those  which  are  accompanied  with  feelings  of  pain  or  discomfort. — Now  in  so  far 
as  the  succession  of  our  thoughts  takes-place  in  accordance  with  the  habitudes 
which  are  thus  determined,  may  we  consider  that  our  character  is  formed  for  us, 
rather  than  by  us;  and  may  look  upon  our  Mental  activity,  whether  it  manifest 
itself  in  the  form  of  Thought  or  of  Feeling,  as  no  less  Automatic  than  the 
instinctive  operations  of  the  lower  animals,  though  far  more  elevated  in  its 
nature. 

628.  But  our  own  consciousness  tells  us  that  there  is  something  in  oui 
Psychical  nature,  that  is  beyond  and  above  this  automatic  exercise  of  our 
powers;  and  that  the  direction  of  our  thoughts,  within  certain  limits,  is  placed 
under  the  control  of  the  Will.  These  limits  are  partly  universal,  and  partly 
peculiar  to  the  individual.  It  may  be  stated  as  a  fundamental  axiom,  that  the 
Will  can  originate  nothing;  its  power  being  limited  to  the  selection  and  intensifi- 
cation of  what  is  actually  before  the  consciousness.  Thus  no  one  has  ever 
acquired  the  creative  power  of  Genius,  or  made  himself  a  great  Artist  or  a  great 
Poet,  or  gained  by  practice  that  peculiar  insight  which  characterises  the  original 
Discoverer;  for  these  gifts  are  mental  instincts  or  intuitions,  which  may  be 
developed  and  strengthened  by  due  cultivation,  but  which  can  never  be  gene- 
rated de  novo.  It  not  unfrequently  happens,  however,  that  such  gifts  lie  dor- 
mant, until  some  appropriate  impression  excites  them  to  activity ;  and  it  is  then 
that  we  most  obviously  see  what  the  Will  can  do  to  perfect  and  utilize  them,  by 
exercising  them  under  circumstances  most  fitted  to  expand  and  elevate,  and  by 
restraining  them  from  all  that  would  limit  or  debase.  In  regard  to  every  kind 
of  mental  activity  that  does  not  involve  origination,  the  power  of  the  Will,  though 
limited  to  selection,  is  otherwise  unbounded.  For  although  it  cannot  directly 
bring  objects  before  the  consciousness  which  are  not  present  to  it,  yet  it  can  con- 
centrate the  mental  gaze  (so  to  speak)  upon  any  object  that  may  be  within  its 
reach,  and  can  make  use  of  this,  as  we  shall  hereafter  see,  to  bring-in  other 
objects  by  suggestion  or  association.  And,  moreover,  it  can  virtually  determine 
what  shall  not  be  regarded  by  the  Mind,  through  its  power  of  keeping  the 
attention  fixed  in  some  other  direction  ;  and  thus  it  can  subdue  the  force  of  vio- 
lent impulse,  and  give  to  the  conflict  of  opposing  motives  an  issue  quite  different 
from  that  which  would  ensue  without  its  interference.  This  exercise  of  the  Will, 
moreover,  if  habitually  exerted  in  certain  directions,  will  tend  to  form  the  'cha- 


574  FUNCTIONS   OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

racter/  by  establishing  a  set  of  acquired  habitudes;  which,  no  less  than  those 
dependent  upon  original  constitution  and  circumstances,  help  to  determine  the 
consequences  of  any  particular  state  of  the  thoughts  and  feelings. 

629.  We  have  seen  that,  in  those  actions  of  the  Nervous  system  (as  of  other 
parts  of  the  body)  in  which  the  Will  is  not  concerned,  we  have  simply  to  con- 
sider the  two  elements  of  which  we  take  account  in  all  scientific  inquiry  ;  namely, 
the/o?re  that  operates,  and   the  organized  structure  on   and   through  which  it 
operates,  —  in  other  words,  the  dynamical  agency,  and  the  material  conditions. 
And  if  we  could  imagine  a  being  to  grow-up  from   infancy  to  maturity,  with  a 
mind  in  the  state  of  that  of  a  *  biologized '  subject  (§  672),  we  should  see  that 
it  would  be  strictly  correct  to  speak  of  his  character  as  formed  for  him  and  not 
by  him  ;  all  his  thoughts,  feelings,  and  actions  being  but  the  reflex  of  his  own 
nature  upon  the  impressions  made  upon  it;  and  that  nature  being  determined  in 
part  by  original  constitution,  and  in  part  by  the  mode  in  which  it  is  habitually 
called  into  action.  —  This  last  condition  is  one   that  is  peculiar  to  a  living  and 
growing  organism  ;  and  it  is  one  which  cannot  be  too  strongly  or  too  constantly 
kept  in  mind.     A  mere  inorganic  substance  reacts  in  precisely  the  same  mode  to 
mechanical,   chemical,  electrical,  or   other  agencies,  however   frequently  these 
are  brought  to  bear  upon  it,  provided  it  has  been   restored  to  its  original  con- 
dition ;  thus  water  may  be  turned  into  steam,  the  steam  condensed  into  water, 
and  the  water  raised  into  steam  again,  any  number  of  times,  without  the  slightest 
variation  in  the  effects  of  the  heat  and  cold  which  are  the  efficient  causes  of  the 
change.     But  every  kind  of  activity  peculiar  to  a  living  body,  involves  (as  has 
been  repeatedly  shown)  a  change  of  structure ;  and  the  formation  of  the  newly- 
generated  tissue  receives  such  an  influence  from  the  conditions  under  which  it 
originates,  that  all  its  subsequent  activity  displays  their  impress.     The  readiness 
with  which  particular  habitudes  of  thought  are  formed,  varies  greatly  in  different 
individuals  and  at  different  periods  of  life.     As  a  general  rule,  it  is  far  greatei 
during  the  period  of  growth  and  development,  than  after  the  system  has  come  to 
its  full  maturity;  and  remembering  that  those  new  functional  relations  between 
other  parts  of  the  Nervous  system,  which  give  rise  to  the  'secondarily-automatic* 
movements  or  acquired  instincts,  are  formed  during  the  same  period,  it  seems 
fair  to  surmise  that  the  substance  of  the  Cerebrum  grows-to  the  conditions  under 
which  it  is  habitually  exercised.     Hence,  as  its  subsequent  nutrition  (according 
to  the  general  laws  of  assimilation,  §  346)  takes-place  on  the  same  plan,  we  can 
understand  the  well-known  force  of  early  associations,  and  the  obstinate  persis- 
tence of  early  habits  of  thought. 

630.  This  view,  indeed,  must  be  extended  to  that  remarkable  hereditary  trans- 
mission of  psychical   character,  which  presents  itself  under  circumstances  that 
entirely  forbid  our  attributing  it  to  any  agency  that  can  operate  subsequently  to 
birth,  and  which  it  would  seem  impossible  to  account-for  on  any  other  hypothesis, 
than  that  the  formative  capacity  of  the  germ  determines  the  subsequent  develop- 
ment of  the  Brain,  as  of  other  parts  of  the  body,  and  (through  this)  its  mode 
of  activity,  in  accordance  with  the  influences  under  which   that  germ  was  first 
impregnated.     And  thus  what  we  speak-of  as  the  '  original  constitution '  of  each 
individual,  is  in   great  part   (if  not   entirely)  determined    by  the  conditions, 
dynamical  and  material,  of  the  parent-organisms; 'a  convincing  proof  of  which 
general  fact,  is  afforded  by  a  careful  examination  of  the  parental  constitution  and 
habits,  in  a  large  proportion  of  cases  of  Idiocy.1     Whatever  may  be  the  conge- 
nital constitution,  however,  there  can  be  no  question  that  this  is  liable  to  great 
modification  from  external  influences,  both  such  as  directly  affect  its  physical  con- 
ditions, and  such  as  operate  through  the  consciousness,  in  determining  the  course 
of  thought  and  feeling,  before  the  individual  has  acquired  any  self-determining 

1  A  most  valuable  collection  of  data  on  this  subject  is  afforded  by  Dr.  Howe's  admirable 
*  Report  on  Idiocy'  made  to  the  Legislature  of  Massachusetts,  of  which  an  abstract  is  con- 
tained in  the  "American  Journal  of  the  Medical  Sciences,"  April,  1849. 


SUCCESSION    OF    PSYCHICAL   STATES: — LAWS    OF   ASSOCIATION.       5<O 

power.  Of  this  influence  of  physical  agencies,  we  have  a  typical  example  in  the 
phenomena  of  Cretinism;  since,  although  the  conditions  under  which  that  state 
is  developed  have  not  yet  been  precisely  determined,  no  one  can  reasonably  doubt 
that  they  are  such  as  act  in  the  first  instance  in  modifying  the  nutrition  and 
activity  of  the  bodily  organism  in  general,  and  of  the  Nervous  system  in  par- 
ticular. 

631.  But,  further,  the  psychical  tendencies  of  every  one  undergo  a  consecu- 
tive change  in  the  progress  of  life.     Infancy,  Childhood,  Youth,  Adolescence, 
Adult  age,  the  period  of  Decline,  and  Senility,  have  all  their  characteristic  phases 
of  psychical  as  of  physical  development  and  decline;    and  this  is  shown,  not 
merely  in  the  general  advance  of  the  Intellectual  powers  up  to  the  period  of 
middle   life,  and  in   their  subsequent  decay;  but  in  a  gradual  change  in  the 
balance  of  the  springs  of  action  which  are  furnished  by  the  Emotional  states,  the 
pleasures  and  pains  of  each  period  being  (to  a  certain  extent)  of  a  different  order 
from  those  of  every  other.     This  diversity  may  be  partly  attributed  to  changes 
in  the  physical  constitution ;  thus,  the  sexual  feeling,  which  has  a  most  powerful 
influence  on  the  direction  of  the  thoughts  in  adolescence,  adult  age,  and  middle 
life,  has  comparatively  little  effect  at  the  earlier  and  later  periods.     So,  again, 
the  thirst  for  novelty,  and  the  pleasure  in  mental  activity,  which  so  remarkably 
characterize  the  young,  when  contrasted  with  the  obtuseness  to  new  impressions 
and  the  pleasure  in  tranquil  occupations,  which  mark  the  decline  of  life,  may 
perhaps  be  attributed,  in   part  at  least,  to  the  greater  activity  of  the  changes, 
both  of  disintegration  and  reparation,  of  which  the  Nervous  system  (in  common 
with  the  rest  of  the  organized  fabric)  is  the  subject  during  the  earlier  part  of 
life,  and  to  its  diminished  activity  as  years  advance.     But  there  are  other  changes 
which  cannot  be  so  distinctly  traced  to  any  physical  source,  but  which  yet  are 
sufficiently  constant  in  their  occurrence  to  justify  their  being  regarded  as  a  part 
of  the  developmental  history  of  the  psychical  nature ;  so  that  each  of  the  '  Seven 
Ages  of  Man '  has  its  own  character,  which  may  be  with  difficulty  defined  in 
\vords,  but  which  is  recognized  by  the  apprehension,  as  it  forces  itself  upon  th« 
experience,  of  every  one. 

632.  Laws  of  Association.  —  The  most  powerful  agency  in  the  Automatic  de- 
termination of  the  succession  of  our  Mental  states,  is  undoubtedly  that  tendency 
which  exists  in  all  Minds  that  have  attained  the  Ideational  stage  of  development, 
to  the  Association  of  Ideas;  that  is,  to  the  formation  of  such  a  connection 
between  two  or  more  ideas,  that  the  presence  of  one  tends  to  bring  the  other  also 
before  the  consciousness;  or,  in   other  words,  each  tends  to  suggest  the  other. 
Certain  Laws  of  Association,  expressive  of  the  conditions  under  which  this  con- 
nection is  formed,  and  the  mode  in  which  it  acts,  have  been  laid  down  by 
Psychologists ;  and  these  may  be  concisely  stated  as  follows  : — 1.  Law  of  Conti- 
guity.    Two  or  more  states  of  consciousness,  habitually  existing  together  or  in 
immediate  succession,  tend  to  cohere,  so  that  the  future  occurrence  of  any  of 
them  is  sufficient  to  restore  or  revive  the  other.     It  is  thus  (to  take  a  simple  il- 
lustration) that  the  impressions  made  upon  our  sensational  consciousness  by  natu- 
ral objects,  which  are  usually  received  through  two  or  more  senses  at  once,  are 
compacted  into  those  aggregate  notions,  which,  however  simple  they  may  appear, 
are  really  the  result  of  the  intimate  combination  of  many  distinct  states  of  idea- 
tion.    Thus  our  notion  of  the/wm  of  an  object  is  made-up  of  separate  notions 
derived  from  the  visual  and  muscular  senses  respectively;  our  notion  of  the  cha- 
racter of  its  surface,  from  the  combination  of  impressions  received  through  the 
visual  and  tactile  senses ;  and  with  both  of  these  our  notion  of  colour,  as  in  the 
case  of  an  orange,  may  be  so  blended,  that  we  do  not  readily  conceive  of  its  cha- 
racteristic form  and  surface,  without  al<o  having  before  our  minds  the  hue  with 
which  these  have  been  always  associated  in  our  experience.     So,  again,  the  ex- 
ternal aspect  of  a  body  suggests   to  our  minds  its  internal  arrangement  and 
qualities,  such  as  we  have  before  found  them  invariably  to  be;  thus,  to  use  the 


576  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

preceding  illustration,  the  shape  and  colour  of  the  orange  bring  before  our  con- 
sciousness  its  fragrant  odour  and  agreeable  taste,  as  well  as  the  internal  structure 
of  the  fruit.     And  our  notion  of  'an  orange'  must  be  considered  as  the  aggre- 
gate of  all  the  preceding  ideas.  —  Not  only  the  different  ideas  excited  by  one 
object,  but  those  called-up  by  objects  entirely  dissimilar,  may  thus  come  to  be 
associated,  provided  that  the  mind  has  been  accustomed  to  the  presentation  of 
them   in  frequent  contiguity  one  with  the  other.     Such  conjunctions  may  be 
natural,  that  is,  they  may  arise  out  of  the  '  order  of  nature ;'  or  they  may  be  ar- 
tificial, being  due  to  human  arrangements ;  all  that  is  requisite  is,  that  they 
should  have  sufficient  permanence  and  constancy  to  habituate  our  minds  to  the 
association.  —  Of  this  law  of  contiguity,  moreover,  we  have  a  most  important 
example  in  the  association  which  the  mind  early  learns  to  form  between  succes- 
sive events,  so  that  when   the  first  has  been  followed  by  the  second  a  sufficient 
number  of  times  to  form  the  association,  the  occurrence  of  the  first  suggests  the 
idea  of  the  second ;  if  that  idea  be  verified  by  its  occurrence,  a  definite  expecta- 
tion is  formed ;  and  if  that  expectation  be  unfailingly  realized,  the  idea  acquires 
the  strength  of  a  belief.     And  thus  it  is  that  we  come  to  acquire  that  part  of 
the  notion  of  l  cause  and  effect/  which  consists  in  invariable  and  necessary  se- 
quence, and  to  form  our  fundamental  conception  of  the  invariability  of  Nature. 
It  is  by  the  same  kind  of  operation  again,  that  we  come  to  employ  words  as  the 
symbols   of  ideas,   for   the   convenience    of  intercommunication   and   reference 
(§  613) ;  a  certain  number  of  repetitions  of  the  sound,  concurrently  with  the 
sight  of  the  object,  or  the  suggestion  of  the  notion  of  that  object,  being  sufficient 
to  establish  the  required  relation  in  our  minds.     Of  the  large  share  which  this 
kind  of  action  takes  in  the  operations  of  Memory  and  Recollection,  evidence  will 
be  presently  given.1 

633.  But  a  not  less  important  ( tendency  to  thought,'  and  one  whose  operation 
is  more  concerned  in  all  the  higher  exercises  of  our  Reasoning  faculties,  is  that 
which  may  be  expressed  under  the  designation  of  the  Law  of  Similarity,  and  which 
consists  in  the  general  fact  that  any  present  state  of  consciousness  tends  to  revive 
previous  states  that  are  similar  to  it.  It  is  thus  that  we  instinctively  invest  a 
new  object  with  the  attributes  we  have  come  to  recognize  in  one  that  we  have 
previously  examined,  to  which  the  new  object  bears  such  a  resemblance,  that  the 
eight  of  the  latter  suggests  those  ideas  which  our  minds  connect  with  the  former. 
Thus,  we  will  suppose  a  man  to  have  once  seen  and  eaten  an  orange ;  when  he 
sees  an  orange  a  second  time,  although  it  may  be  somewhat  larger  or  smaller, 
somewhat  rougher  or  smoother,  somewhat  lighter  or  darker  in  hue,  he  recognizes 

1  It  is  a  curious  example  of  the  automatic  action  of  the  mind,  in  accordance  with  the 
laws  of  Association,  that  a  young  child  who  happens  to  possess  two  modes  of  communica- 
ting its  ideas,  seems  unconsciously  to  select  that  which  is  conformable  to  the  receptivity 
of  the  person  addressed.  —  Thus,  Dr.  C.  B.  Radcliffe  ("Philosophy  of  Vital  Motion,"  p. 
137)  mentions  the  case  of  a  child  belonging  to  an  English  family  resident  in  Germany,  who 
had  acquired  the  power  of  speaking  on  ordinary  matters  either  in  German  or  English, 
without  confusing  the  words  or  idioms :  but  who  yet  seemed  invariably  compelled  to  reply 
in  the  language  of  the  person  he  was  addressing.  Thus,  in  conveying  a  message  to  his 
German  nursery-maid,  he  delivered  it  in  German,  though  it  had  been  received  the  moment 
previously  in  English ;  but  on  returning  to  the  English  family  in  the  parlor,  if  asked  what 
the  maid  had  said,  he  answered  in  English  as  often  as  the  question  was  proposed  in 
English;  and  even  though  pressed  to  give  the  words  he  had  heard  in  the  nursery,  he  still 
continued  to  do  the  same,  without  seeming  to  be  aware  of  the  difference.  But  if  the 
question  was  put  to  him  in  German,  the  answer  was  in  German,  there  being  the  same 
inability  to  reply  in  English,  as  there  had  previously  been  to  give  a  German  answer  to 
the  English  question.  —  So  Dr.  Kitto  ("The  Lost  Senses,"  vol.  i.  p.  97)  tells  us  that  his 
children,  in  their  successive  infancies,  would  begin  to  imitate  the  finger-language  whenever 
they  saw  him,  even  whilst  they  were  yet  in  arms,  and  could  have  no  true  cognizance  of 
his  peculiar  condition. — The  more  carefully,  indeed,  the  actions  of  Childhood  are  observed, 
the  more  obvious  does  it  become  that  they  are  solely  prompted  by  ideas  and  feelings 
which  automatically  succeed  one  another,  in  uncontrolled  accordance  with  the  laws  of 
suggestion. 


SUCCESSION   OF   PSYCHICAL   STATES: — LAWS   OF   ASSOCIATION.      577 

't  as  '  an  orange/  and  mentally  assigns  to  it  the  fragrance  and  sweetish  acidity  of 
the  one  which  he  had  previously  eaten.  But  if,  instead  of  being  yellow,  the 
fruit  were  green,  he  would  doubt  of  its  being  an  orange;  and  if  assured  that  it 
still  was,  but  had  not  come  to  maturity,  he  would  no  longer  expect  to  find  it 
sweet,  the  notion  of  intense  acidity  being  suggested  to  his  mind  by  his  previous 
experience  of  other  green  and  unripe  fruit. — It  is  in  virtue  of  this  kind  of 
action,  that  we  extend  those  elementary  notions  which  are  primarily  excited  by 
sensation,  to  new  objects.  Thus,  the  idea  of  roundness  (like  other  notions  of 
form)  is  originally  based  on  the  combination  of  the  muscular  and  visual  sensa- 
tions, and  must  be  first  acquired  by  a  process  of  considerable  complexity ;  but 
when  once  derived  from  the  examination  of  a  single  object,  it  is  readily  extended 
to  other  objects  of  the  same  character. — So,  again,  it  is  by  the  operation  of  this 
mental  tendency,  that  we  recognize  similarity  where  it  exists  in  the  midst  of  dif- 
ference, and  separate  the  points  of  agreement  from  those  of  discordance;  and 
this,  again,  not  merely  as  regards  objects  which  are  before  our  consciousness  at 
the  same  time  or  in  close  succession,  but  also  with  regard  to  all  past  states  of 
consciousness.  It  is  thus  that  we  identify  and  compare,  that  we  lay  the  foun- 
dations of  classification,  and  that  we  recover  all  past  impressions  which  have  any- 
thing in  common  with  our  present  state  of  consciousness.  The  intensity  of  this 
tendency,  and  the  habitual  direction  which  it  takes,  vary  extremely  in  different 
individuals.  Some  have  so  great  an  incapacity  for  recognizing  similarity,  that 
they  can  only  perceive  it  when  it  is  in  marked  prominence,  their  minds  taking 
much  stronger  note  of  differences;  whilst  others  have  a  strong  bias  for  the  detec- 
tion of  resemblances  and  analogies,  and  discover  them  where  ordinary  minds 
cannot  recognize  them.  Some,  again,  address  themselves  to  the  discovery  of 
similarity  among  objects  of  sense,  whilst  others  study  only  those  ideas  which  are 
the  objects  of  our  internal  consciousness;  and  it  is  in  the  detection  of  what  is 
essentially  similar  among  the  latter,  that  all  the  higher  operations  of  the  intel- 
lect essentially  consist.  Even  here  we  find  that  some  are  contented  with  super- 
ficial analogies,  whilst  others  are  not  satisfied  until  they  have  penetrated  by 
analysis  to  the  depths  of  the  subject,  and  are  able  to  compare  its  fundamental 
idea  with  others  of  like  kind. — It  may  be  remarked  that  this  modo  of  action 
of  the  mind  is  in  some  degree  opposed  to  the  preceding ;  for  whilst  contiguity 
leads  to  the  arranging  of  ideas  as  they  happen  to  present  themselves  in  natural 
juxtaposition,  and  thus  to  induce  a  routine  which  is  often  most  unmeaning 
(§  676),  similarity  breaks  through  juxtaposition,  and  brings  together  like  objects 
from  all  quarters. 

634.  It  is  this  habit  of  mind,  which  is  of  essential  value  in  all  the  sciences  of 
Clarification  and  Induction.  Thus,  in  the  formation  of  generic  definitions  to 
include  the  characters  which  a  number  of  objects  have  in  common,  their  subor- 
dinate differences  being  for  a  time  left  out  of  view,  we  are  entirely  guided  by 
the  recognition  of  similarity  between  the  objects  we  are  arranging ;  and  the  same 
is  the  case  in  the  formation  of  all  the  higher  groups  of  families,  orders,  and 
classes,  the  points  of  similarity  becoming  fewer  and  fewer  as  we  proceed  to  the 
more  comprehensive  groups,  whilst  those  of  difference  increase  in  corresponding 
proportion.  The  sagacity  of  the  Naturalist  is  shown  in  the  selection  of  the  best 
points  of  resemblance,  as  the  foundation  of  this  classification ;  the  value  of  charac- 
ters being  determined,  on  the  one  hand  by  their  constancy,  and  on  the  other  by 
their  degree  of  coincidence  with  important  features  of  general  organization  or  of 
physiological  history.1  In  the  determination  of  Physical  laws,  the  process  is  some 
what  of  the  same  kind;  but  the  similarities  with  which  we  have  here  to  do,  are 
nut,  as  in  the  preceding  case,  objective  resemblances,  but  exist  only  among  our 

1  Thus,  for  example,  it  is  now  generally  admitted  amongst  Zoologists,  that  the  Impla- 
cental  Mammalia  should  constitute  a  separate  sub-class,  in  virtue  of  the  peculiar  confor- 
mation of  their  generative  apparatus,  instead  of  being  distributed  among  other  Orders,  a* 
were  left  by  Cuvier. 

37 


578  FUNCTIONS   OF   THE   CEREBRO- SPINAL   NERVOUS   SYSTEM. 

subjective  ideas  of  the  nature  and  causes  of  the  phenomena  brought  under  our 
consideration.  Thus,  there  is  no  obvious  relation  between  the  fall  of  a  stone  to 
the  Earth,  and  the  motion  of  the  Moon  in  an  elliptical  orbit  around  it;  but  the 
penetrating  mind  of  Newton  detected  a  relation  of  common  causation  between 
these  two  phenomena,  which  enabled  him  to  express  them  both  under  one  law. 
It  was  by  a  like  intellectual  perception  of  similarity,  that  Franklin  was  led  to 
determine  the  identity  of  Lightning  with  the  spark  from  an  Electrical  machine. 
And  it  would  be  easy  to  show  that  it  has  been  in  their  extraordinary  development 
of  this  power  of  recognizing  causative  similarity,  leading  to  a  kind  of  Intuitive 
perception  of  its  existence  where  as  yet  no  adequate  ground  can  be  assigned  by 
the  Reason  for  such  a  relationship,  that  those  men  have  been  eminent,  who  have 
done  the  most  to  advance  science  by  the  process  of  inductive  generalization. 

635.  The  same  kind  of  mental  action  is  also  employed  in  the  contrary  direc- 
tion ;  namely,  in  that  application  of  general  laws  to  particular  instances,  which 
constitutes  Deductive,  Reasoning  ;  and  in  that  extension  of  generic  definitions  to 
new  objects,  which  takes-place  upon  every  discovery  of  new  species.     "We  may 
trace  it  again,  even  in  the  extension  of  the  meaning  of  words  so  as  to  become 
applicable  to  new  orders  of  ideas,  in  consequence  of  the  resemblance  which  the 
latter  are  felt  to  bear  to  those  of  which  the  words  were  previously  the  symbols : 
as  in  the  application  of  the  word  'head/  which  primarily  designated  the  most 
elevated  part  of  the  human  body,  in  such  phrases  as  the  '  head  of  a  house/  the 
'  head  of  a  state/  the  '  head  of  an  army/  the  ( head  of  a  mob/  in  each  of  which 
the  idea  of  superiority  and  command  is  involved ;  or  in  the  phrases  the  '  heads 
of  a  discourse/  or  the  '  heads  of  an  argument/  in  which  we  still  trace  the  idea  of 
authority  or  direction ;  or  in  the   phrases  the  '  head  of  a  table/  the  '  head  of  a 
river,'  in  which  the  idea  of  superiority  or  origin  comes  to  be  locally  applied ;  or 
in  the  '  head  of  a  bed/  or  'head  of  a  coffin/  in  which  we  have  the  more  distinct 
local  association  with  the  position  of  the  head  of  man.     Of  the  foregoing  appli- 
cations, those  first  cited  belong  to  the  nature  of  a  metaphor,  which  has  been 
defined  to  be  "  a  simile  comprised  in  a  word  /'  and  the  judicious  use  of  metaphors, 
which  frequently  adds  force  as  well  as  ornamental  variety  to  the  diction,  is  most 
seen  amongst  men  who  possess  a  great  power  of  bringing-together  the  '  like '  in 
the  midst  of  the  l  unlike/ 

636.  Every  eifort,  in  fact,  to  trace-out  unity,  consistency,  and  harmony,  in  the 
midst  of  the  wonderful  and  (at  first  sight)  perplexing  variety  of  objects  and 
phenomena  amidst  which  we  are  placed,  is  a  manifestation  of  this  tendency  of 
the  Human  Mind ;  and,  when   conducted  in  accordance  with  the  highest  teach- 
ings of  the  Intellect,  or  guided  by  that  Intuition  which  in  some  minds  supersedes 
and  anticipates  all  reasoning,  it  enables  us  to  rise  towards  the  comprehension  of 
that  great  Idea  of  the  Universe,  which  we  believe  to  exist  in  the  Divine  Mind, 
in  a  majestic  simplicity  of  which  we  can  here  but  faintly  conceive,  and  of  which 
all  the  phenomena  of  Nature  are  but  the  manifestations  to  our  consciousness. — 
With  this  purely  intellectual  operation,  there  is  frequently  associated  a  peculiar 
feeling  of  pleasure,  which  constitutes  a  true   Emotional  state.     All  the  disco- 
veries of  Identification,  where  use  and  wont  are  suddenly  broken  through,  and  a 
common  feature  is  made  known  among  objects  previously  looked-on  as  entirely 
different,  produce  a  flash  of  agreeable  surprise,  and  the  kind  of  sparkling  cheer- 
fulness that  arises  from  the  sudden  lightning  of  a  burden.     There  are  few  who 
devote  themselves  to  the  pursuit  of  Science,  who  do  not  experience  this  pleasure, 
either  from  the  detection  of  new  relations  of  similarity  by  their  own  perception 
of  them,  or  in  the  recognition  of  them  as  developed  by  others.     It  is,  however, 
much  more  intense  in  some  minds  than  in  others ;  and  according  to  its  intensity, 
will  it  act  as  a  motive  in  the  prosecution  of  scientific  inquiry  amidst  discourage- 
ments and  difficulties.     It  is  recorded  of  Newton,  that  when  he  was  bringing  his 
great  idea  of  the  causative  relation  between  terrestrial  gravity  and  the  motions 
of  the  heavenly  bodies,  to  the  test  of  calculation,  his  agitation  became  so  great, 


SUCCESSION   OF   PSYCHICAL   STATES  : — LAWS    OF   ASSOCIATION.      579 

that  he  could  not  complete  the  computation,  and  was  obliged  to  request  a  friend 
to  do  so. 

637.  Although  the  single  relations  established  between  Ideas,  either  through 
Contiguity  or  through  Similarity,  may  suffice  for  their  mutual  connection,  yet, 
that  connection  becomes  much  stronger  when  two  or  more  such  relations  exist 
consentaneously.     Thus,  if  there  be  present  to  our  minds  two  states  of  conscious- 
ness, each  of  them  associated,  either  by  contiguity  or  similarity,  with  some  third 
state  that  is  past  and  'out  of  mind'  at  the  time,  the  compound  action  is  more 
effective  than  either  action  would  be  separately  ;  that  is,  although  the  suggestions 
might  be  separately  too  weak  to  revive  the  past  state  of  consciousness,  they  re- 
produce it  by  acting  together.     Of  this,  which  has  been  termed  the  Law  of  Com- 
pound Association,  we  have  examples  continually  occurring  to  us  in  the  pheno- 
mena of  Memory;  but  it  is  especially  brought  into  operation  in  the  voluntary 
act  of  Recollection  (§  644). 

638.  Another  mode  in  which  the  Associative  tendency  operates,  is  in  the  for- 
mation of  aggregate  conceptions  of  things  that  have  never  been  brought  before 
our  consciousness  by  sensory  impressions.     This  faculty,  which  has  been  termed 
that  of  Constructive  Association,  is  the  foundation  of  Imagination ;  and  it  is  ex- 
ercised in  every  other  mental  operation,  in  which  we  pass  from  the  known  to  the 
unknown.     When  we  attempt  to  form  a  conception,  which  shall  differ  from  one 
that  we  have  already  experienced  as  a  matter  of  objective  reality,  by  the  intro- 
duction of  only  a  single  new  element, — as  when  we  imagine  a  brick  building 
replaced  by  one  of  stone,  in  every  respect  similar  as  to  size  and  form, — we  sub- 
stitute in  our  minds  the  idea  of  stone  for  that  of  brick,  and  associate  it  by  the 
principle  of  contiguity  with  those  other  ideas,  of  which  that  of  the  whole  build- 
ing is  an  aggregate.     So,  again,  if  we  conceive  a  known  building  transferred 
from  its  actual  site  to  some  other  already  known  to  us,  we  dissociate  the  existing 
combinations,  and  keep-together  the  ideas  which  were  previously  separated,  until 
their  contiguity  has  so  intimately  united  them,  that  the  picture  of  the  supposed 
combination  may  present  itself  to  the  mind  exactly  as  if  it  had  been  a  real  scene 
which  we  had  long  and  familiarly  known.     By  a  further  extension  of  the  same 
power,  we  may  conceive  the  elements  to  be  varied,  as  well  as  the  mode  of  theh* 
combination ;  and  thus  we  may  bring  before  our  consciousness  a  representation, 
in  which  no  particular  has  ever  been  present  to  our  minds  under  any  similar 
aspect,  and  which  is,  therefore,  as  a  whole  entirely  new  to  us,  notwithstanding 
that,  when  we  decompose  it  into  its  ultimate  elements,  we  shall  find  that  each  of 
these  has  been  previously  before  our  consciousness.     Such  a  representation,  by 
being  continually  d welt-on,  many  come  to  have  all  the  force  and  vividness  of  one 
derived  from   an  actual  sensory  impression ;  and  we  can  scarcely  conceive  but 
that  the  actual  state  of  the  Sensorium  itself  must  be  the  same  in  both  cases, 
though  this  state  is  induced  in  the  one  case  by  an  act  of  Mind,  and  in  the  other 
by  objective  impressions. — A  very  common  modus  operandi  of  this  'constructive 
association/  is  the  realization  of  a  landscape,  a  figure,  or  a  countenance,  from  a 
pictorial  representation  of  it.     Every  picture  must  be   essentially  defective  in 
some  of  the  attributes  of  the  original,  as,  for  example,  in  the  representation  of 
the  projection  of  objects;  and  all,  therefore,  that  the  picture  can  do,  is  to  suy- 
<j<-st  to  the  mind  an  idea,  which  it  completes  for  itself  by  this  constructive  pro- 
cess, so  as  to  form  an  aggregate  which  may  or  may  not  bear  a  resemblance  to  the 
original,  according  to  the  fidelity  of  the  picture,  and  the  mode  in  which  it  acts 
upon  the  mind  of  the  individual.     Thus  to  one  person  a  mere  sketch  shall  con- 
vey a  much  more  accurate  notion  of  the  object  represented,  than  a  more  finished 
picture  shall  give  to  another;  because  from  practice  in  this  kind  of  mental 
reconstruction,  the  former  recognizes  the  true  meaning  of  the  sketch,  and  fills  it 
up  in  his  '  mind's  eye ;'  whilst  the  latter  can  see  little  but  what  is  actually  before 
his  bodily  vision,  and  interprets  as  a  literal  presentation  that  which  was  intended 
merely  as  a  suggestion.     And  it  is  now  generally  admitted,  that  in  all  the  higher 


580  FUNCTIONS    01    THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

forms  of  representative  Art,  the  aim  should  be,  not  to  call  into  exercise  the 
faculty  of  mere  objective  realization,  but  to  address  that  higher  power  of  ideali- 
zation, which  invests  the  conception  suggested  by  the  representation,  with  attri- 
butes more  exalted  than  those  actually  possessed  by  the  original,  yet  not  incon- 
sistent with  them.  It  depends,  however,  as  much  on  the  mind  of  the  individual 
addressed,  as  on  that  of  the  Artist  himself,  whether  such  conceptions  shall  be 
formed  ;  since  by  those  who  do  not  possess  this  power,  the  highest  work  of  Art 
is  only  appreciated,  in  so  far  as  it  enables  them  to  realize  the  object  which  it 
may  represent. 

639.  Intellectual  Faculties. — Having  thus  pointed-out  what  may  be  considered 
the  most  elementary  forms  of  Mental  Action,1  we  shall  briefly  pass  in  review 
those  more  complex  operations,  which  may  be  regarded  as  in  great  part  com- 
pounded of  them.     The  capacity  for  performing  these  is  known  as  the  Intellect 
or  the  Reasoning  Power;  and  the  capacities  for  those  various  forms  of  Intel- 
lectual activity,  which  it  is  convenient  to  distinguish  for  the  sake  of  making  our- 
selves more  fully  acquainted  with  them,  are  termed  'Intellectual  Faculties/     It 
appears  to  the  Author,  however,  to  be  a  fundamental  error  to  suppose,  that  the 
entire   Intellect  can   be   split-up  into  a  certain   number  of  faculties;  for  each 
faculty  that  is  distinguished  by  the  Psychologist,  expresses  nothing  else  than  a 
mode  of  activity,  in  which  the  whole  power  of  the   Mind  may  be  engaged  at 
once, — just  as  the  whole  power  of  the  locomotive  steam-engine  may  be  employed 
in  carrying  it  forwards  or  backwards,  according  to  the  direction  given  to  its 
action.     And  if  this  be  true,  it  must  be  equally  erroneous  to  attempt  to  parcel- 
out  the  Cerebrum  into  distinct  '  organs '  for  these  respective  faculties ;  the  whole 
of  it  (so  far  as  we  can  form  a  judgment)  being  called  into  operation,  in  every 
kind  of  intellectual  process  which  occupies  the  attention  at  the  time. 

640.  We  have  seen  (§  592)  that  the  Consciousness  may  either  be  the  passive 
recipient  of  the  impressions  of  external  objects,  or  may  be  actively  directed 
towards  them  ;   and  that  in  the  latter  state,  it  may  single-out,  from  amongst  a 
iarge  number  of  impressions  that  present  themselves  simultaneously,  some  parti- 
cular group,  whose  force  becomes  extraordinarily  intensified,  whilst  the  remainder 
pass  entirely  unnoticed.     This  state  of  Attention  may  be  either  automatic  or  voli- 
tional; being  the  result,  in  some  instances,  of  the  force  of  the  impression,  or  of 
the  peculiar  attractiveness  which  the  object  may  happen  to  possess  for  us  ;  whilst 
it  may  also  be  induced  by  a  determinate  effort  of  the  Will. — Now  the  very  same 
difference  between  our  states  of  Consciousness  exists  in  relation  to  Mental  opera- 
tions ;  which  may  take  place,  on  the  one  hand,  without  more  than  a  passive  cog- 
nizance of  them  on  our  own  part;  whilst,  on  the  other  hand,  our  Attention  may 
be  actively  directed  to  them.     And  the  same  difference  exists  also  in  regard  to 
the  result  of  this  direction;  for  the  Mental  state,  of  whatever  nature  it  may  be, 
upon  which  the  Attention  is  fixed,  becomes  intensified  to  such  a  degree,  as  to 
exclude  for  the  time  the  cognizance  of  other  operations,  and  to  acquire  a  peculiar 
power  of  suggesting  other  Mental  states  with  which  it  may  have  some  link  of 
Association  (§  644).     This   direction    of  the  Attention    to   states  of  Cerebral 
activity,  may,  like  its  direction  to  impressions  received  through  the  Organs  of 
Sense,  be    either   automatic   or   volitional.     In   the   former  case,  the  mind  is 
engrossed  for  the  time  by  some  idea  or  emotion,  in  virtue  of  the  intensity  with 
which  it  has  been  called-up,  or  of  the  peculiar  hold  which  it  has  upon  our  nature ; 
and  it  may  remain  thus  fixed,  until  this  mental  state  shall  have  given-rise  to  some 
other,  or  shall  have  expended  its  force  in  bodily  action,  or  until  the  attention  has 
been  determinately  detached  from  it  by  an  exertion  of  the  Will.     In  the  latter 

1  In  the  foregoing  brief  exposition  of  the  laws  and  leading  phenomena  of  Mental  As- 
sociation, the  Author  has  derived  great  aid  from  the  excellent  article  on  <  The  Human 
Mind,'  contributed  to  Messrs.  Chambers's  "  Information  for  the  People,"  by  his  friend  Mr. 
Alexander  Bain. — Though  not  agreeing  with  all  the  views  expressed  in  that  article,  the 
Author  can  cordially  recommend  the  perusal  of  it  to  his  readers. 


INTELLECTUAL    FACULTIES  I — M  EMORY.  581 

case,  the  mental  gaze  is  fixed  (so  to  speak)  by  a  purposive  effort,  upon  some  single 
state,  or  on  some  class  of  ideas  or  feelings,  which  the  individual  desires  to  make 
the  special  object  of  contemplation ;  and  it  is  by  means  of  this  selecting  power, 
and  of  the  tendency  of  the  mental  state  thus  intensified,  to  call-forth  other  states 
with  which  it  has  pre-formed  links  of  association,  that  the  Will  possesses  that 
power  of  directing  the  current  of  thought  and  feeling,  which  characterizes  the 
fully-developed  Man  (§§  668,  669). — Thus  it  is  in  the  degree  of  attention  which 
we  bestow,  upon  certain  classes  of  ideas  presented  to  us  by  Suggestion,  that  our 
power  of  using  our  Minds  in  any  particular  mode  consists;  and  hence  we  see  the 
fundamental  importance  of  early  learning  to  fix  our  attention,  and  to  resist  all 
influences  which  would  tend  to  distract  it.  And  this  is  essential,  not  merely  to 
the  advantageous  employment  of  our  Intellectual  powers,  but  also  to  the  due  regu- 
lation of  our  Emotional  nature;  for  it  is  by  fixing  the  attention  upon  those  states 
of  feeling  which  we  desire  to  intensify,  and  conversely,  by  withdrawing  it  from 
those  which  we  desire  to  repress  (which  is  most  easily  effected  by  choosing  some 
other  object  that  exercises  a  healthful  attraction  towards  us),  that  we  can  encou- 
rage the  growth  of  what  we  recognize  as  worthy,  and  can  keep  in  check  what  we 
know  to  be  wrong  or  undesirable. 

641.  The  intentional  direction  of  the  attention  to  external  objects,  is  what  is 
commonly  known   as  Observation;  those  men  being  designated  as  ' observant,' 
who  do  not  allow  their  attention  to  be  so  far  engrossed  by  one  object  or  occur- 
rence, or  (as  very  frequently  happens)  by  their  own   trains  of  thought,   as  to 
exclude  the  cognizance  of  what  may  be  taking  place  around  them ;  whilst  those 
are  spoken-of  as  '  unobservant/  who,  by  allowing  their  consciousness  to  remain 
fixed  upon  some  one  object  or  train  of  thought,  prevent  it  from  receiving  a  legiti- 
mate degree  of  influence  from  other  impressions  received  and  transmitted  to  the 
Sensorium  by  the  organs  of  sense.     That  intentional  direction  of  our  conscious- 
ness to  what  is  passing  within  us,  which  not  merely  intensifies  the  mental  state, 
but  separates  and  brings  it  forwards  as  a  subject  of  observation,  is  sometimes 
designated  as  Reflection,  but  is  more  appropriately  termed  Introspection. 

642.  The  reproduction  of  past  states  of  consciousness  by  either  of  the  forms  of 
suggestive  action  already  described,  constitutes  what  is  known  as  Memory.1 — 
There  seems  much  ground  for  the  belief,  that  every  ideational  state  which  has 

1  It  is  commonly  stated  that  Memory  consists  in  the  renewal  of  past  sensations  and  of 
the  ideas  they  have  excited  ;  but  it  may  be  questioned  whether  we  can  primarily  bring  to 
our  minds  anything  else  than  the  impressions  left  by  ideas,  and  whether  the  recall  of  sensa- 
tions is  not  a  secondary  change,  dependent  upon  the  reaction  of  ideational  (Cerebral) 
changes  upon  the  Sensorium.  For  if  we  wish  to  reproduce  any  sensational  state, — whether 
visual,  auditory,  olfactive,  gustative,  or  tactile, — we  first  recall  the  notion  of  some  object  by 
which  that  state  was  formerly  produced ;  and  it  is  only  by  keeping  that  notion  strongly 
before  our  consciousness,  that  we  can  bring  ourselves  to  see,  hear,  smell,  taste,  or  feel, 
that  which  we  desire  to  experience.  Indeed  it  is  not  every  one  who  can  thus  reproduce 
sensational  states,  the  general  notion  being  most  commonly  all  that  is  arrived-at;  of  this 
we  have  a  good  illustration  in  the  conception  we  form  of  the  face  of  an  absent  friend,  it 
being  only  a  comparatively  small  number  of  persons  who  are  able  to  reproduce  the  visual 
image  with  sufficient  distinctness  to  serve  as  a  model  for  delineation,  although  a  much 
larger  number  would  be  able  to  say  how  far  such  a  delineation  realized  their  own  concep- 
tion of  the  countenance,  and  to  point-out  in  what  it  might  depart  from  this.  It  is  a  fur- 
ther confirmation  of  this  view,  that  the  expression  of  a  countenance,  which  directly  appeals 
to  our  ideational  consciousness,  is  much  more  distinctly  remembered  by  most  persons  than 
the  features,  the  recognition  of  which  is  more  dependent  upon  the  recall  of  antecedent  sen- 
sational states. — What  is  true  of  the  act  of  Recollection  in  this  particular,  is  probably  true 
also  in  great  degree  of  spontaneous  Memory;  but  perhaps  we  should  admit  that  the  renewal 
of  past  states  of  sensational  consciousness  may  be  effected  by  fresh  sensory  impressions 
which  are  closely  allied  to  them ;  as  would  seem  probable  from  the  fact,  that  we  find  our- 
selves comparing  the  new  sensations  with  the  old,  without  having  in  the  mean  time  formed 
any  distinct  conception  of  the  object  by  which  the  old  were  produced.  And  the  fact  has 
been  already  noticed  (g  591),  that  sensorial  impressions  have  been  automatically  repro- 
duced, with  which  it  did  not  seem  likely  that  ideas  had  ever  been  connected 


582  FUNCTIONS    OF   THE   CEREBRO-SP1NAL   NERVOUS    SYSTEM. 

even  transiently  occupied  the  consciousness,  is  registered  (so  to  speak)  in  the 
Cerebrum,  and  may  be  reproduced  at  some  subsequent  time,  although  there  may 
be  no  consciousness  of  its  existence  in  the  mind  during  the  whole  intermediate 
period.  Instances  are  of  very  frequent  occurrence,  in  which  ideas  come-up 
before  the  mind  during  delirium  or  dreaming,  and  are  expressed  at  the  time  or 
are  subsequently  remembered,  although  the  individual  cannot  himself  retrace 
them  as  having  ever  before  been  present  to  his  consciousness ;  they  being  yet 
proved  to  have  been  so  at  some  long  antecedent  period.1  The  instrumentality  of 
the  Cerebrum  in  this  mental  operation  is  strongly  indicated  by  the  fact,  that  dis- 
ease or  injury  of  that  organ  may  destroy  the  Memory  generally,  or  may  affect  it 
in  various  remarkable  modes.  Thus  we  not  unfrequently  meet  with  cases,  in 
which  the  brain  has  been  weakened  by  attacks  of  epilepsy  or  apoplexy,  in  such  a 
manner  as  to  prevent  the  reception  of  any  new  impressions ;  so  that  the  patient 
does  not  remember  anything  that  passes  from  day  to  day ;  whilst  the  impressions 
of  events  which  happened  long  before  the  commencement  of  his  malady,  recur 
with  greater  vividness  than  ever.  On  the  other  hand,  the  memory  of  the  long- 
tdrice-past  is  sometimes  entirely  destroyed;  whilst  that  of  events  which  have  hap- 
pened subsequently  to  the  malady,  is  but  little  weakened.  The  memory  of  parti- 
cular classes  of  ideas  is  frequently  destroyed  ;  that  of  a  certain  language,  or  some 
branch  of  science,  for  example.  The  loss  of  the  memory  of  words  is  another  very 
curious  form  of  this  disorder,  which  not  unfrequently  presents  itself:  the  patient 
understands  perfectly  well  what  is  said,  but  is  not  able  to  reply  in  any  other  terms 
than  yes  or  no — not  from  any  paralysis  of  the  muscles  of  articulation,  but  from 
his  incapability  of  expressing  the  ideas  in  language.  Sometimes  the  memory  of 
a  particular  class  of  words  only,  such  as  nouns  or  verbs,  is  destroyed ;  or  it  may 
be  impaired  merely,  so  that  the  patient  mistakes  the  proper  terms,  and  speaks  a 
most  curious  jargon.  So,  again,  a  person  may  remember  the  letters  of  which  a 
word  is  composed,  and  may  be  able  to  spell  his  wants,  though  he  cannot  speak  the 
word  itself;  asking  for  bread  (for  example)  by  the  separate  letters  b,  r,  e,  a,  d 
A  very  curious  affection  of  the  memory  is  that  in  which  the  sound  of  spoken 
words  does  not  convey  any  idea  to  the  mind;  yet  the  individual  may  recognize  in 
a  written  or  printed  list  of  words,  those  which  have  been  used  by  the  speaker,  the 
sight  of  them  enabling  him  to  understand  their  meaning.  Conversely,  the  sound 
of  the  word  may  be  remembered,  and  the  idea  it  conveys  fully  appreciated;  but 
the  visual  memory  of  its  written  form  may  be  altogether  lost,  although  the  com- 
ponent letters  may  be  recognized. — For  this  class  of  phenomena,  in  which  there 
is  rather  a  severance  of  the  associative  connections  that  have  been  formed  between 
distinct  states  of  consciousness,  than  an  actual  annihilation  of  the  impression  left 
by  any  of  the  latter,  the  term  '  dislocation  of  memory '  has  been  proposed  by  Sir 
H.  Holland;2  but,  as  he  justly  remarks,  "no  single  term  can  express  the  various 
effects  of  accident,  disease,  or  decay,  upon  this  faculty,  so  strangely  partial  in 
their  aspect,  and  so  abrupt  in  the  changes  they  undergo,  that  the  attempt  to  clas- 
sify them  is  almost  as  vain  as  the  research  into  their  cause."  It  is,  perhaps,  in 
the  sudden  changes  produced  by  blows  or  falls,  that  we  have  the  most  extraordi- 
nary examples  of  this  kind  of  disturbance ;  and  it  is  scarcely  less  extraordinary, 
that  there  should  sometimes  be  a  no  less  sudden  recovery  of  the  lost  power,  which 
we  can  scarcely  do  wrong  in  attributing  to  the  return  of  the  Cerebral  organization 
to  that  previous  condition  of  activity  from  which  it  had  been  perverted. 

643.  When  we  take  all  these  phenomena  into  consideration,  we  can  scarcely 

1  A  remarkable  instance  is  mentioned  by  a  writer  (Miss  H.  Martineau?)  in  "  Household 
Words,"  vol.  ix.  p.  200,  of  a  congenital  Idiot  who  had  lost  his  mother  when  under  two 
years  old,  and  who  could  not  have  subsequently  been  made  cognizant  of  anything  relating 
to  her;  and  who  yet,  when  dying  at  the  age  of  thirty,  "  suddenly  turned  his  head,  looked 
bright  and  sensible,  and  exclaimed  in  a  tone  never  heard  from  him  before,  «  Oh  my  mother  1 
bow  beautiful!'  and  sunk  round  again — dead." 

?  See  his  "Chapters  on  Mental  Physiology,"  p.  146. 


INTELLECTUAL   FACULTIES: — REASONING   POWERS.  583 

resist  the  conclusion  that  every  act  of  ideational  consciousness  produces  a  certain 
modification  in  the  nutrition  of  the  Cerebrum  j  that  the  new  mode  of  nutrition 
is  continued  according  to  the  laws  of  Assimilation  already  adverted-to ;  and  that 
thus  the  Cerebrum  forms  itself  in  accordance  with  the  use  that  is  made  of  it. 
And  this  unconscious  storing-up  of  impressions,  which  can  only  be  brought  before 
the  consciousness  (under  ordinary  circumstances  at  least)  by  the  connecting  link 
of  associations,  affords  a  powerful  argument  for  the  doctrine  which  has  already 
oeen  frequently  referred-to  as  probable, — that  the  Cerebrum  is  not  itself  a  centre 
of  consciousness,  but  that  we  only  become  conscious  of  its  states,  in  the  same  man- 
ner as  we  do  of  those  of  the  lietina  and  of  other  surfaces  for  the  reception  of 
external  impressions,  by  means  of  the  communication  of  the  changes  which  take 
place  in  it  to  the  Sensorium. 

644.  Although  the  term  Memory  is  very  commonly  used  to  designate  the 
intentional  recall  of  past  states  of  consciousness,  as  well  as  their  '  spontaneous' 
or  *  automatic'  recurrence,  yet  it  is  properly  restricted  to  the  latter  operation ; 
the  term  Recollection  being  that  which  is  appropriate  to  the  former,  whose  pecu- 
liarity consists  in  the  exertion  of  the  Will  to  bring  that  before  the  consciousness, 
which  does  not  spontaneously  present  itself  to  it.  As  this  process  affords  a  typi- 
cal example  of  the  mode  in  which  the  Will  acts  in  directing  the  current  of  thought, 
we  shall  examine  it  a  little  more  minutely. — In  the  first  place  it  may  be  posi- 
tively affirmed,  that  we  cannot  call-up  any  idea  by  simply  willing  it ;  for  it  is  a 
necessary  condition  of  an  act  of  will,  that  there  should  be  in  the  mind  an  idea 
of  what  is  willed  j  and  if  the  idea  of  the  thing  willed  be  already  in  the  mind,  it 
is  obviously  impossible  to  use  the  will  to  bring  it  there.  But  every  one  is  con- 
scious of  the  state  of  mind,  in  which  he  tries  to  remember  something  which  is 
not  at  the  time  present  to  his  consciousness ;  and  the  question  is,  how  he  pro- 
ceeds to  bring  the  idea  before  it.  The  process  really  consists  in  the  fixation  of 
the  attention  upon  one  or  more  of  the  ideas  already  present  to  the  mind,  which 
may  directly  recall,  by  suggestion,  that  which  is  desiderated ;  the  very  act  of 
thus  attending  to  a  particular  idea,  serving  not  only  to  intensify  the  idea  itself, 
but  also  to  strengthen  the  associations  by  which  it  is  connected  with  others. 
There  are  certain  ideas  so  familiar  to  us,  that  they  seem  necessarily  to  recur  upon 
the  slightest  prompting  of  suggestion ;  yet  even  with  regard  to  these,  the  volun- 
tary recollection  at  any  particular  time  involves  the  process  just  described.  Thus 
if  a  man  be  asked  his  name,  he  usually  finds  no  difficulty  in  giving  the  proper 
answer,  because  it  only  requires  that  his  attention  should  be  directed  to  the  idea 
involved  in  the  words  '  my  name/  to  suggest  the  words  of  which  that  name  niay 
consist.  But  if  the  individual  should  be  in  that  state  of  '  absence  of  mind/  which 
really  consists  in  the  fixation  of  the  attention  upon  some  internal  train  of  thought, 
he  may  not  be  able  on  the  sudden  to  transfer  his  attention  to  the  new  idea  that 
is  forced  upon  his  consciousness  ab  externo  ;  and  may  thus  hesitate  and  bungle, 
before  he  is  able  to  answer  the  question  with  positiveness.  So,  again,  it 
sometimes  happens  in  old  age,  that  men  fail  to  recollect  their  own  names,  or 
the  names  of  persons  most  familiar  to  them,  in  consequence  of  the  weakening  of 
the  bond  of  direct  association ;  and  they  then  only  recall  it  by  the  operation  to 
be  presently  described.  And  there  are  states  of  mind,  in  which  the  power  of 
voluntarily  directing  the  thoughts  is  for  a  time  suspended,  and  in  which  the 
individual  cannot  make  the  slightest  effort  to  recall  the  most  familiar  fact,  espe- 
cially if  possessed  with  the  conviction  that  such  effort  is  impossible  (§  672). 

645.  But  supposing  the  mind  to  be  in  full  possession  of  its  ordinary  powers, 
and  the  desiderated  idea  to  be  one  which  does  not  at  once  recur  on  the  direction 
of  the  attention  to  some  idea  already  in  the  mind ;  we  then  apply  the  same  pro- 
cess to  other  ideas  which  successively  come  before  our  consciousness,  selecting 
those  which  we  recognize  as  most  likely  to  suggest  that  which  we  require,  and 
following-out  one  train  of  thought  after  another,  in  the  directions  which  we  deem 
most  productive,  until  we  either  succeed  in  finding  the  idea  of  which  we  are  in 


584  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

search,  or  give-up  the  pursuit  as  not  worth  further  trouble.  Thus  a  man  who  is 
making-up  his  accounts,  and  finds  that  he  has  expended  a  sum  in  a  mode  which 
he  cannot  recollect,  sets  himself  to  remember  what  business  he  has  done,  where 
he  has  recently  been,  what  shops  he  may  have  entered,  and  so  on.  Or  when  a 
man  meets  another  whom  he  recognizes  as  an  acquaintance  without  remembering 
his  name-,  he  runs-over  a  number  of  names  (one  being  suggested  by  another, 
when  the  attention  is  given  to  them),  in  hopes  that  some  one  of  these  may  prove 
to  be  the  one,  which,  when  brought  to  his  mind,  is  recognized  as  that  of  the 
object  then  before  his  consciousness;  or  he  thinks  of  the  place  in  which  he  may 
have  previously  seen  him,  this  being  recalled  by  fixing  the  attention  on  the  asso- 
ciation suggested  by  the  sight  of  his  face  and  figure,  or  by  the  sound  of  hia 
voice*  or  by  his  personality  altogether;  or  he  endeavours  to  retrace  the  time 
which  has  elapsed  since  he  last  met  with  him,  the  persons  amongst  whom  he 
then  was,  or  the  actions  in  which  he  was  engaged ;  that  some  one  or  other  of 
these  various  associations  may  suggest  the  desiderated  name. 

646.  Upon  the  various  Ideational  states  thus  reproduced  before  the  Mental 
consciousness,  and  sequentially  connected  in  '  trains  of  thought'  by  the  operation 
of  Suggestion,  all  acts  of  Reasoning  are  founded.     These  consist,  for  the  most 
part,  in  the  aggregation  and  collocation  of  ideas,  the  decomposition  of  complex 
ideas  into  more  simple  ones,  and  the  combination  of  simple  ideas  into  general 
expressions;   in  which  processes  are  exercised   the  faculty  of  Comparison,  by 
which  the  relations  and  connections  of  ideas  are  perceived, — that  of  Abstraction, 
by  which  we  mentally  isolate  from  the  rest  any  particular  quality  of  the  object 
of  our  thought, — and  that  of  Generalization,  by  which  we  recognize  the  common 
properties  we  have  abstracted,  as  composing  a  distinct  notion,  that  of  some  genus 
in  which  the  objects  are  comprehended.     These  operations,  when  carefully  an- 
alyzed, seem  capable  of  reduction  to  this  one  expression, — namely,  the  fixation 
of  our  Attention  on  some  particular  classes  of  ideas,  from  among  those  which 
Suggestion  brings  before  our  consciousness  ;    and   this  fixation   may  result,  as 
already  shown,  either  from  the  peculiar  attractiveness  which  these   classes  of 
ideas  have  for  us  (the  constitution  of  individual  minds  varying  greatly  in  this 
respect),  or  on  the  determination  of  our  own  Will. — There  is  strong  reason  to 
believe  that  these  processes  may  be  performed  automatically  to  a  very  consider- 
able extent,  without  any  other  than  a  permissive  act  of  Will.     It  is  clearly  by 
such  automatic  action  that  the  before-mentioned  '  fundamental  axioms'  or  l  second- 
ary intuitions'  (§  614)  are  evolved;  and  there  is  not  one  of  the  operations  above 
described,  which  may  not  be  performed  quite  involuntarily,  especially  by  an  indi- 
vidual who  is  naturally  disposed  to  it.     Thus  to  some  persons,  the  tendency  t<? 
compare  any  new  object  of  consciousness  with  objects  that  have  been  previously 
before  the  mind,  is  so  strong  as  to  be  almost  irresistible ;  and  this,  or  any  other 
original  tendency,  is  strengthened  by  the  habit  of  acting  in  conformity  with  it. 
So,  again,  the  tendency  to  abstract  is  equally  strong  in  the  minds  of  others,  who 
instinctively  seek  to  separate  what  is  fundamental  and  essential  in  the  properties 
of  objects,  from  what  is  superficial  and  accidental ;  and  their  attention  being  most 
attracted  by  the  former,  they  readily  recognize  the  same  characters  elsewhere, 
and  are  thus  as  prone  to  combine  and  generalize,  as  others  are  to  analyse  and 
distinguish. 

647.  It  is  only,  in  fact,  when  we  intentionally  divert  the  current  of  thought 
from  the  direction  in  which  it  was  previously  running, — when  we  determine  to 
put  our  minds  in  operation  in  some  particular  manner, — and  make  a  choice  of 
means  adapted  to  our  end  (as  in  the  act  of  Recollection  already  described)  by 
purposely  fixing  our  attention  upon  one  class  of  objects  and  excluding  others, — 
that  we  can  be  said  to  use  the  Will  in  our  Intellectual  processes ;  and  this  exer- 
cise of  it  is  shown,  by  the  analysis  of  our  own  consciousness,  to  be  much  rarer 
than  is  commonly  supposed.     Thus  we  may  imagine  a  man  sitting-down  at  a  fixed 
hour  every  day;  to  vrrite  a  treatise  upon  a  subject  which  he  has  previously  thought- 


INTELLECTUAL    FACULTIES:  —  IMAGINATION.        585 

out;  after  that  first  effort  of  Will  by  which  his  determination  was  made,  the  daily 
continuance  of  his  task  becomes  so  habitual  to  him,  that  no  fresh  exertion  of  it 
is  required  to  bring  him  to  his  desk;  and  unless  he  feels  unfit  for  his  work,  or 
some  other  object  of  interest  tempt  him  away  from  it,  so  that  he  is  called-upon  to 
decide  between  contending  motives,  his  Will  cannot  be  fairly  said  to  be  brought 
into  exercise.  It  may  need,  perhaps,  some  voluntary  fixation  of  his  attention 
upon  the  topics  upon  which  he  had  been  engaged  when  he  last  dropped  the  thread, 
to  enable  him  to  recover  it,  so  as  to  commence  his  new  labours  in  continuity  with 
the  preceding;  but  when  once  his  mind  is  fairly  engrossed  with  the  subject,  this 
developes  itself  before  his  consciousness  according  to  his  previous  habits  of  mental 
action;  ideas  follow  one  another  in  rapid  and  continuous  succession,  clothe  them- 
selves in  words,  and  prompt  the  movements  by  which  those  words  are  expressed 
in  writing;  and  this  automatic  action  may  continue  uninterruptedly  for  hours, 
without  any  tendency  of  the  mind  to  wander  from  its  subject,  the  Will  being 
only  called  into  play  when  the  feeling  of  fatigue  or  the  distraction  of  other  objects 
renders  it  difficult  to  keep  the  attention  fixed  upon  that  which  has  previously  held 
it  by  its  own  attractive  power. — The  converse  of  this  condition  is  experienced, 
when  some  powerful  interest  tends  to  draw-off  the  attention  elsewhere,  and  the 
thoughts  are  found  to  wander  continually  from  the  subject  in  hand;  or  when, 
from  the  undue  protraction  of  mental  exertion,  the  state  of  the  brain  is  such,  that 
the  thoughts  no  longer  develope  themselves  consecutively  in  the  mind,  nor  shape 
themselves  into  appropriate  forms  of  expression.  In  either  of  these  cases,  the 
intellectual  powers  can  only  be  kept  in  action  upon  the  predetermined  subject, 
by  a  strong  effort  of  the  Will :  of  this  effort  we  are  conscious  at  the  time,  and  feel 
that  we  need  to  put-forth  even  a  greater  power  than  that  which  would  be 
required  to  generate  a  large  amount  of  physical  force  through  the  muscular  sys- 
tem ;  and  we  subsequently  experience  the  results  of  it,  in  the  feeling  of  excessive 
fatigue  which  always  follows  any  such  exertion. 

648.  The  faculty  of  Imagination  is  in  some  respects  opposed  in  its  character 
to  that  of  Reason ;  being  chiefly  concerned  about  fictitious  objects,  instead  of 
real  ones.  Still,  it  is  in  a  great  degree  an  exercise  of  the  same  powers,  though 
in  a  different  manner  (§  638).  Thus  it  is  partly  concerned  in  framing  new  com- 
binations of  ideas  relating  to  external  objects,  and  is  hence  an  extended  exercise 
of  Conception ;  placing  us,  in  idea,  in  scenes,  circumstances,  and  relations,  in 
which  actual  experience  never  found  us;  and  thus  giving  rise  to  a  new  set  of 
objects  of  thought.  In  fact,  every  Conception  of  that  which  has  not  been  itself 
an  object  of  perception,  may,  strictly  speaking,  be  regarded  as  the  result  of  the 
exercise  of  Imagination.  Now  the  new  Conceptions  or  mental  creations  thus 
formed,  take  their  character,  in  great  degree  from  the  .^Esthetic  and  Emotional 
tendencies  of  the  mind  ;  so  that  the  previous  development  of  these  affections  will 
influence,  not  merely  the  selection  of  the  objects,  but  the  mode  in  which  they  are 
thus  idealized.  In  the  higher  efforts  of  the  Imagination,  the  mind  is  not  so  much 
concerned  with  the  class  of  sensational  ideas,  as  with  those  of  the  intellectual 
character ;  and  the  collocation,  analysis,  and  comparison  of  these,  by  which  new 
forms  and  combinations  are  suggested  to  the  mind,  involve  the  exercise  of  the 
same  powers  as  those  concerned  in  acts  of  Reasoning;  but  they  are  exercised 
in  a  different  way.  Whilst  the  Imagination  thus  depends  upon  the  Intellectual 
powers  for  all  its  higher  operations,  the  understanding  may  be  said  to  be  equally  ( 
indebted  to  the  imagination  ;  for  the  ideal  combinations,  which  are  the  results 
of  the  action  of  the  latter,  do  not  merely  engage  the  attention  of  the  Artist, 
who  aims  to  develope  them  in  material  forms,  but  are  the  great  sources  of  the 
improvement  of  the  knowledge  and  happiness  possessed  by  our  race, — operating 
alike  in  the  common  affairs  of  life,  by  suggesting  those  pictures  of  the  future 
which  are  ever  before  our  eyes,  and  are  our  animating  springs  of  action,  with 
their  visions  of  enjoyment,  never  perhaps  to  be  fully  realized,  and  their  prospects 
of  anticipated  evil  that  often  prove  to  be  an  exaggeration  of  the  reality, — prompt- 


586  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

ing  the  investigations  of  Science,  that  are  gradually  unfolding  the  sublime  plan 
on  which  the  Universe  is  governed, — and  leading  to  a  continual  aspiration  after 
those  higher  forms  of  Moral  and  Intellectual  beauty,  which  are  inseparably  con- 
nected with  purity  and  love. 

649.  When    the   limitation  which  attaches   to   the   exercise   of  Volition, — 
namely,  its  incapacity  to  originate  mental  activity  of  any  kind  (§  628), — is  kept 
in  view,  it  becomes  at  once  apparent  that  the  power  of  the  Will  over  the  Imagi- 
nation must  be  greatly  inferior  to  that  which  it  may  exert  over  the  Reasoning 
processes.     For  all  that  it  can  do  is  to  give  the  Imaginative  faculty  fair  play,  by 
withdrawing  all  influences  that  would  tend  to  distract  it,  and  by  bringing-together 
those  external  conditions  which  are  found  (in  the  case  of  each  individual)  to  be 
most  favourable  to  its  exercise ;  it  may  help,  too,  by  selecting  from  among  the 
ideas  or  feelings  already  before  the  consciousness,  those  which  are  felt  to  be  most 
appropriate  in  themselves,  or  most  likely  to  be  fertile  in  serviceable  suggestions ; 
and  thus  the  faculty  may  be  directed  and  invigorated,  cultivated  and  chastened, 
although  its  productiveness  depends  essentially  on  its  own  inherent  fertility  and 
on  the  energy  of  its  automatic  action. 

650.  Two  striking  instances  may  be  adduced,  of  men  distinguished,  the  one 
ibr  Intellectual,  the  other  for  Artistic  ability ;  in  both  of  whom  the  mental  action 
which  evolved  the  result,  seems  to  have  been  almost  entirely  of  an  automatic 
character. — All  accounts  of  Coleridge's  habits  of  thought,  as  manifested  in  his 
conversation  (which  was  a  sort  of  thinking  aloud}  agree  in  showing  that  his  train 
of  mental  operations,  once  started,  went  on  of  itself,  sometimes  for  a  long  dis- 
tance in  the  original  direction,  sometimes  with  a  divergence  into  some  other  track, 
according  to  the  consecutive  suggestions  of  his  own  mind,  or  to  new  suggestions 
introduced  into  it  from  without.     His  whole  course  of  life  was  one  continued 
proof  of  the  weakness  of  his  Will  ;  for,  with  numerous  gigantic  projects  continu- 
ally in  his  mind,  he  could  never  bring  himself  even  seriously  to  attempt  to  exe- 
cute any  one  of  them ;  and  his  utter  deficiency  in  self-control  rendered  it  neces- 
sary for  his  welfare  that  he  should  yield  himself  to  the  control  of  others.     The 
composition  of  the  poetical  fragment  "  Kubla  Khan  "  in  his  sleep,  is  a  typical 
example  of  automatic  mental  action  ;  and  almost  his  whole  life  might  be  regarded, 
in  consequence  of  the  deficiency  of  that  self-determining  power  which  is  the  pre- 
eminent characteristic  of  every  really  great  mind,  as  a  sort  of  waking  dream.1 
One  of  the  most  characteristic  examples  of  his  extraordinary  deficiency  of  Will 
was  displayed  very  early  in  his  career;  for  when  he  had  found  a  bookseller  (Mr. 
Cottle)  generous  enough  to  promise  him  fifty  guineas  for  poems  which  he  recited 
to  him,  and  might  have  received  the  whole  sum  immediately  on  delivering  the 
Manuscript,  he  went-on,  week  after  week,  begging  and  borrowing  for  his  daily 
needs,  in  the  most  humiliating  manner,  until  he  had  drawn  from  his  patron  the 
whole  of  the  promised  purchase-money,  without  supplying  him  with  a  line  of  that 
poetry  which  he  had  only  to  write-down  to  free  himself  from  obligation.     Yet 
there  was  probably  no  man  of  his  day  who  surpassed  Coleridge  in  the  combination 
of  the  Reasoning  powers  of  the  Philosopher  with  the  Imagination  of  the  Poet  and 
the  Inspiration  of  the  Seer;  and  there  was  perhaps  not  one  of  the  last  genera- 
tion, who  has  left  so  strong  an  impress  of  himself  in    the  subsequent  course  of 
thought  of  reflective  minds  engaged  in  the  highest  subjects  of  Human  contem- 
plation.— So,  Again,  the  whole  artistic  life   of  Mozart,  from   his  infancy  to  his 
death,  save  in  so  far  as  the  earlier  part  of  it  was  directed  by  his  father,  may  be 
cited  as  an  example  of  the  spontaneous  or  automatic  development  of  musical 
ideas,  which,  under  the  guidance  of  his  intuitive  sense  of  harmony  (§  607),  ex- 
pressed themselves  in  appropriate  language.    When  only  four  years  old,  he  began 
to  write  music,  which  was  found  to  be  in  strict  accordance  with  the  rules  of 
composition,  although  he  had  received  no  instruction  in  these.     And  when  en- 

•  The  most  striking  portraiture  of  Coleridge's  habits  of  conversation,  is  to  be  found  in 
CarlyJe's  ••  Life  of  John  Sterling." 


INTELLECTUAL   FACULTIES  I— THEIR   AUTOMATIC    ACTION.  587 

prated,  during  his  after-life,  in  the  production  of  those  works  which  have  ren- 
dered his  name  immortal,  it  was  enough  for  him  to  fix  his  thoughts  in  the  first 
instance  upon  the  subject  (the  libretto  of  an  opera,  for  example,  or  the  words  of 
a  religious  service)  so  as  to  give  the  requisite  start  and  direction  to  his  ideas,  which 
then  flowed  onwards  without  any  effort  of  his  own  ;  so  that  the  whole  of  a  Sym- 
phony or  an  Overture  would  develope  itself  in  his  mind,  its  separate  instrumental 
parts  taking  (so  to  speak)  their  respective  shapes,  without  any  intentional  elabo- 
ration. In  fact,  the  only  exercise  of  Will  that  seemed  to  be  required  on  his 
part,  consisted  in  the  noting-down  of  the  composition  when  complete ;  and  this, 
under  the  temptations  of  social  intercourse,  and  a  dislike  to  anything  like  l  work/ 
he  would  sometimes  postpone  until  the  last  moment.  Thus  it  is  well  known 
that  his  overture  to  Don  Giovanni  was  only  written-out  (although  it  must  have 
been  previously  composed,)  during  the  night  previous  to  its  performance, 
which  took  place  without  any  rehearsal.  It  is  recorded  of  him,  that  being 
once  asked  by  an  inferior  musician,  how  he  set  to  work  to  compose  a  symphony, 
he  replied — "  If  you  once  think  of  how  you  are  to  do  it,  you  will  never  write 
anything  worth  hearing,  /write  because  I  cannot  help  it."  Mozart,  like  Cole- 
ridge, was  a  man  of  extremely  weak  will  ;  he  could  neither  keep  firm  to  a  reso- 
lution, nor  resist  temptation  ;  and  when  not  under  the  guidance  of  his  excellent 
wife,  was  the  sport  of  almost  every  kind  of  impulse.  But  there  was  probably 
never  a  more  remarkable  example  than  his  musical  career  presents,  of  the  auto- 
matic operation  of  that  creative  power  which  specially  constitutes  Genius ;  and 
his  life  is  altogether  a  most  interesting  study  to  the  Psychologist,  as  well  as  to 
the  Musician.1 

661.  On  the  other  hand,  in  the  life  and  literary  career  of  Southey,  we  have  a 
striking  example  of  what  a  determined  Will,  acting  under  a  strong  sense  of 
Duty,  may  do  in  utilizing  and  turning  to  the  best  account  endowments  of  a 
comparatively  mediocre  order.  Although  few  of  his  poems  may  retain  a  lasting 
celebrity,  yet  his  prose  writings  will  always  be  models  of  excellence  in  composi- 
tion; and  he  had  his  powers  under  such  complete  command,  that  he  never  failed 
(save  from  physical  incapacity)  to  execute  those  engagements  which  are  too  often 
made  by  men  of  genius  "  only  to  be  broken  "  and  never  shrank  from  what  he 
felt  to  be  a  task  of  disagreeable  drudgery,  when  once  he  had  undertaken  it. 

652.  But  not  only  is  much  of  our  highest  Mental  Activity  thus  to  be  regarded 
as  the  expression  of  the  automatic  action  of  the  Cerebrum : — we  seem  justified 
in  proceeding  further,  and  in  afiirming  that  the  Cerebrum  may  act  upon  impres- 
sions transmitted  to  it,  and  may  elaborate  results  such  as  we  might  have  attained 
by  the  purposive  direction  of  our  minds  to  the  subject,  without  any  consciousness 
on  our  own  parts;  so  that  we  only  become  aware  of  the  operation  which  has 
taken-place,  when  we  compare  the  result,  as  it  presents  itself  to  our  minds  after 
it  has  been  attained,  with  the  materials  submitted  to  the  process.  The  ordinary 
experience  of  most  persons  will  supply  them  with  examples  of  this  form  of 
Cerebral  activity.  One  of  the  simplest  instances  of  it  is  to  be  found  in  a  curious 
phenomenon,  which,  though  most  men  are  occasionally  conscious  of  it,  has  been 
scarcely  recognized  by  Metaphysical  inquirers;  namely,  that  when  we  have  been 
trying  to  recollect  some  name,  phrase,  occurrence,  &c.,  and,  after  vainly  employ- 
ing all  the  expedients  we  can  think-of  for  bringing  the  desiderated  idea  to  our 
minds,  have  abandoned  the  attempt  as  useless,  it  will  often  occur  spontaneously 
a  little  while  afterwards,  suddenly  flashing  (as  it  were)  before  the  consciousness ; 
and  this  although  the  mind  has  been  engrossed  in  the  mean  time  by  some 
entirely-different  subject  of  contemplation,  and  cannot  detect  any  link  of  associa- 
tion whereby  the  result  has  been  obtained,  notwithstanding  that  the  whole  train 
of  thought  which  has  passed  through  the  mind  in  the  interval  may  be  most 
distinctly  remembered.2  Now  it  is  difficult,  if  not  impossible,  to  account  for 

1  See  especially  the  "  Life  of  Mozart,"  by  Edward  Holmes. 

a  So  frequently  has  this  occurred  within  the  Author's  experience,  that  he  is  now  in  the 
habit  of  trusting  to  this  method  of  recollection,  where  he  has  re-ison  to  feel  sure  that  the 


588  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

this  fact  upon  any  other  supposition,  than  that  a  certain  train  of  action  has  been 
set-going  in  the  Cerebrum  by  the  voluntary  exertion  which  we  at  first  made ; 
and  that  this  train  continues  in  movement  after  our  attention  has  been  fixed 
upon  some  other  object  of  thought,  so  that  it  goes-on  to  the  evolution  of  its  result, 
not  only  without  any  continued  exertion  on  our  own  parts,  but  also  without  our 
consciousness  of  any  continued  activity. — Another  familiar  example  of  a  like 
Kind,  is  presented  by  the  process  by  which  we  acquire  a  knowledge  of  the  mean- 
ing of  an  author  whose  writings  we  are  perusing.  For,  if  the  subject  be  one 
into  which  we  readily  enter,  and  if  the  writer's  flow  of  thought  be  one  which  we 
easily  follow,  and  his  language  be  appropriate  to  express  his  ideas,  we  acquire 
the  meaning  of  one  sentence  after  another,  without  any  conscious  recognition  of 
the  meaning  of  each  of  its  component  words  ;  and  yet  it  is  certain  that  a  partic- 
ular impression  must  have  been  made  by  each  of  these  words  upon  the  Cere- 
brum, before  we  can  comprehend  the  notion  which  they  were  collectively  intended 
to  convey.  It  is  only  when  the  language  is  ill-chosen,  or  when  we  do  not  readily 
follow  the  author's  train  of  thought,  that  we  direct  our  attention  to  the  significa- 
tion of  the  individual  words,  and  become  conscious  of  their  separate  meaning. 
In  like  manner  an  expert  calculator  will  cast  his  eye  rapidly  from  the  bottom  to 
the  top  of  a  column  of  figures,  and  will  name  the  total,  without  any  conscious 
appreciation  of  the  value  of  each  individual  figure. 

653.  But  in  these  instances,  no  higher  act  of  mind  is  required,  than  the  pro- 
duction of  one  complex  idea  out  of  an  aggregate  of  simpler  elements ;  there  are 
cases,  however,  in  which  processes  of  a  far  more  elaborate  nature  are  carried-on, 
without  necessarily  affecting  our  consciousness.  Most  persons  who  attend  to 
their  own  mental  operations,  are  aware  that  when  they  have  been  occupied  for 
some  time  about  a  particular  subject,  and  have  then  transferred  their  attention  to 
some  other,  the  first,  when  they  return  to  the  consideration  of  it,  may  be  found 
to  present  an  aspect  very  different  from  that  which  it  possessed  before  it  was  put 
aside ;  notwithstanding  that  the  mind  has  since  been  so  completely  engrossed 
with  the  second  subject,  as  not  to  have  been  consciously  directed  towards  the  first 
in  the  interval.  Now  a  part  of  this  change  may  depend  upon  the  altered  condi- 
tion of  the  mind  itself,  such  as  we  experience  when  we  take-up  a  subject  in  the 
morning  with  all  the  vigour  which  we  derive  from  the  refreshment  of  sleep,  and 
find  no  difficulty  in  overcoming  difficulties  and  in  disentangling  preplexities 
which  checked  our  further  progress  the  night  before,  when  we  were  too  weary 
to  give  more  than  a  languid  attention  to  the  points  to  be  made-out,  and  could  use 
no  exertion  in  the  search  for  their  solutions.  But  this  by  no  means  accounts 
for  the  entirely-new  development  which  the  subject  is  frequently  found  to  have 
undergone,  when  we  return  to  it  after  a  considerable  interval ;  a  development 
which  cannot  be  reasonably  explained  in  any  other  mode,  than  by  attributing  it 
to  the  intermediate  activity  of  the  Cerebrum,  which  has  in  this  instance  autom- 
atically evolved  the  result  without  any  consciousness.  Strange  as  this  phenomenon 
may  at  first  sight  appear,  it  is  found,  when  carefully  considered,  to  be  in  complete 
harmony  with  all  that  has  been  already  affirmed,  respecting  the  relation  of  the 
Cerebrum  to  the  Sensoriuru,  and  the  independent  action  of  the  former;  and 
looking  at  all  those  automatic  operations  by  which  results  are  evolved  without 
any  intentional  direction  of  the  Mind  to  them,  in  the  light  of  'reflex  actions'  of 
the  Cerebrum,  there  is  no  more  difficulty  in  comprehending  that  such  reflex 

desired  idea  is  not  far-off,  if  the  mind  can  crnly  find  its  track — as  when  it  relates  to  some 
occurrence  (such  as  a  payment  of  money)  which  is  known  to  have  taken-place  within  a  few 
days  previously  ;  for  he  has  found  himself  much  more  certain  of  recovering  it,  by  with- 
drawing his  mind  from  the  search  when  it  is  not  speedily  successful,  and  by  giving  himself 
up  to  the  occupation  appropriate  to  the  time,  than  by  inducing  fatigue  by  unsuccessful 
efforts.  And  this  is  not  his  own  experience  only,  but  that  of  many  others.  The  fact  has 
been  noticed  by  Sir  H.  Holland  ("Chapters  on  Mental  Physiology,"  p.  66);  from  whom 
be  has  learned  that  the  above  plan  has  been  put  into  successful  action  by  many  to  whom 
he  has  recommended  it. 


INTELLECTUAL    OPERATIONS: — UNCONSCIOUS   CEREBRATION.         589 

actions  may  proceed  without  our  knowledge,  so  as  to  evolve  intellectual  products 
when  their  results  are  transmitted  to  the  Sensorium  and  are  thus  impressed  on 
our  consciousness,  than  there  is  in  understanding  that  impressions  may  excite 
muscular  movements  through  the  '  reflex'  power  of  the  Spinal  Cord,  without  the 
necessary  intervention  of  Sensation.  In  both  cases,  the  condition  of  this  mode 
of  independent  operation,  is  that  the  receptivity  of  the  Sensorium  shall  be  sus- 
pended quoad  the  changes  in  question,  either  by  its  own  functional  inactivity,  or 
through  its  temporary  engrossment  by  other  processes. — It  is  difficult  to  find  an 
appropriate  term  for  this  class  of  operations.  They  can  scarcely  be  designated  as 
Reasoning  Processes,  since  'unconscious  reasoning '  is  a  contradiction  in  terms. 
The  designation  Unconscious  Cerebration  is  perhaps  less  objectionable  than  any 
other.  (See  §  663.) 

654.  But  it  must  not  be  left  out  of  view,  that  Emotional  states,  or  rather 
states  which  constitute  emotions  when  we  become  conscious  of  them,  may  be 
developed  by  the  same  process;  so  that  our  feelings  towards  persons  and  objects 
may  undergo  most  important  changes,  without  our  being  in  the  least  degree 
aware,  until  we  have  our  attention  directed  to  our  own  mental  state,  of  the  alte- 
ration which  has  taken-place  in  them.  A  very  common  but  very  characteristic 
example  of  this  kind  of  action,  is  afforded  by  the  powerful  attachment  which 
often  grows-up  between  individuals  of  opposite  sexes,  without  either  being  aware 
of  the  fact;  the  full  strength  of  this  attachment  being  only  revealed  to  the  con- 
sciousness of  each,  when  circumstances  threaten  a  separation,  and  when  each 
becomes  cognizant  of  the  feelings  entertained  by  the  other.  The  existence  of  a 
mutual  attachment,  indeed,  is  often  recognized  by  a  by-stander  (especially  if  the 
perceptions  be  sharpened  by  jealousy,  which  leads  to  an  intuitive  interpreta- 
tion of  many  minute  occurrences,  which  would  be  without  signification  to 
an  ordinary  observer),  before  either  of  the  parties  has  made  the  discovery, 
whether  as  regards  the  individual  self,  or  the  beloved  object ;  the  Cerebral  state, 
manifesting  itself  in  action,  although  no  distinct  consciousness  of  that  state  has 
been  attained,  chiefly  because,  the  whole  attention  being  attracted  by  the  present 
enjoyment,  there  is  little  disposition  to  Introspection. — The  fact,  indeed,  is  recog- 
nized in  our  own  ordinary  language;  for  we  continually  speak  of  the  'feelings' 
which  we  unconsciously  entertain  towards  another,  and  of  our  not  becoming  aware 
of  them  until  some  circumstances  call  them  into  activity.  Here  again,  it  would 
seem  as  if  the  material  organ  of  these  feelings  tends  to  form  itself  in  accordance 
with  the  impressions  which  are  habitually  made  upon  it ;  so  that  we  are  as  com- 
pletely unaware  of  the  changes  which  may  have  taken  place  in  it,  as  we  are  of 
those  by  which  passing  events  are  registered  in  our  minds  (§  642),  until  some 
circumstance  calls-forth  the  conscious  manifestation,  which  is  the  'reflex'  of  the 
new  condition  which  the  organ  has  acquired.  And  it  may  be  desirable  to  recall 
the  fact  in  this  connection,  that  the  Emotional  state  seems  often  to  be  determined 
by  circumstances  of  which  the  individual  has  no  distinct  consciousness,  and  es- 
pecially by  the  emotional  states  of  those  by  whom  he  is  surrounded  (§  609) ;  a 
mode  of  influence  which  is  exerted  with  peculiar  potency  on  the  minds  of  chil- 
dren, and  which  is  a  most  important  element  in  their  Moral  education.1 

655.  Ideo-Motor  Actions.  —  Although  it  has  been  usual  to  designate  by  the 
term  Voluntary,  all  those  muscular  movements  which  take-place  as  the  result  of 
mental  operations,  save  when  they  are  the  expression  of  Emotional  states,  yet  a 
careful  analysis  of  the  sources  from  which  many  of  even  our  ordinary  actions 
proceed,  will  show  that  the  Will  has  no  direct  participation  in  producing  them, 
and  that  they  are,  Psychologically  speaking,  the  spontaneous  manifestations  of 
Ideational  states  excited  to  a  certain  measure  of  intensity,  or,  in  Physiological 
language,  the  reflex  actions  of  the  Cerebrum.  This  mode  of  operation  has  been 
already  shown  (§§  469,  470)  not  only  to  be  fully  conformable  to  the  general  plan 

1  See  an  admirable  Discourse  on  *  Unconscious  Influences,'  by  the  Rev.  Horace  Buslmell, 
of  Hartford  (N.  E.),  published  in  the  "Penny  Pulpit,"  No.  1199. 


590  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

of  the  activity  of  the  Nervous  System,  but  even  to  complete  or  fill-up  a  part  of 
it  which  would  otherwise  be  left  void ;  and  we  shall  find  that  it  serves  to  account 
for  a  great  number  of  phenomena  which  had  not  previously  been  included  under 
any  general  category,  and  which,  when  thus  combined  and  generalized,  form  a 
most  interesting  and  remarkable  group,  well  deserving  of  attentive  study. — It  is, 
of  course,  when  the  Intellect  is  in  a  state  of  exalted  (though  it  may  be  aberrant) 
activity,  but  when  the  directing  power  of  the  Will  is  suspended  or  weakened, 
that  we  should  expect  to  see  the  most  remarkable  manifestations  of  the  reflex 
power  of  the  Cerebrum ;  and  such  is  the  condition  of  the  Somnambulist  who 
acts  his  dreams  (§  693),  and  of  the  {  Biologized '  subject  who  acts  his  reverie 
(§  672).  In  each  case,  the  mind  is  possessed  by  a  succession  of  ideas,  which 
may  either  be  spontaneously  evolved  by  its  own  operations,  or  may  be  directly 
suggested  through  the  senses,  or  may  be  the  products  of  the  mental  activity  of 
the  individual,  exercised  upon  the  promptings  which  it  has  received  from  with- 
out. In  whatever  mode  the  ideas  have  been  brought  before  the  consciousness,  it 
is  the  essential  characteristic  of  these  states  that  the  Mind  is  entirely  given-up  to 
that  which  may  happen  to  be  before  it  at  the  time,  which  consequently  exerts  an 
uncontrolled  directing  power  over  the  actions,  there  being  no  antagonistic  agency 
to  keep  it  in  check. 

656.  To  this  category,  too,  belong  a  variety  of  aberrant  actions,  bordering  on 
Insanity,  of  which  the  history  of  mankind  in  all  ages  furnishes  us  with  abundant 
examples ;  that  which  is  common  to  all  of  them,  being  the  entire  possession  of 
the  ideational  consciousness  by  some  strongly-excited  '  dominant  idea/  the  inten- 
sity of  which  blinds  the  common-sense  and  subjugates  the  will,  so  that  it  ex- 
presses itself  in  bodily  action  without  the  least  restraint.  The  notion  may,  or  may 
not,  be  in  itself  an  absurd  one.  It  may  be  confined  to  a  single  individual,  or  it 
may  spread  epidemically  through  a  multitude.  It  may  be  one  that  interests  thfc 
feelings,  or  it  may  be  of  a  nature  purely  intellectual.  The  wild  but  transient 
vagaries  of  religious  enthusiasm  in  all  ages,  as  shown  in  the  Pythonic  inspiration 
of  the  Delphic  priestesses  ;  the  ecstatic  revelations  of  Catholic  and  Protestank 
visionaries;  the  preaching  epidemic  among  the  Huguenots  in  France,  and  more 
recently  in  Lutheran  Sweden ;  the  strange  performances  of  the  i  Convulsion- 
naries '  of  St.  Medard,  which  have  been  since  almost  paralleled  at  Methodist 
'  revivals '  and  '  camp-meetings ;' — the  Dancing  Mania  of  the  Middle  Ages  ;  the 
Tarentism  of  Southern  Italy,  the  Tigretier  of  Abyssinia,  and  the  Leaping-ague 
of  Scotland  in  later  times,1 — together  with  that  most  recent,  but  not  least  remark- 
able specimen  (the  character  of  the  inolividuals  affected  being  taken  into  account), 
the  Table-turning  and  Table-talking  epidemic  which  spread  through  almost  the 
whole  civilized  world  in  1852-3;  —  are  all,  with  many  similar  wonders,  to  be 
ranged  under  the  same  category.  The  '  dominant  idea'  not  unfrequently  declines 
in  intensity,  especially  when  it  expends  its  force  in  action,  and  the  mind  sponta- 
neously returns  to  its  previous  condition ;  and  thus  it  is  that  we  find  these  Epi- 
demic Delusions  passing-away  of  themselves,  without  any  ostensible  cause  for 
their  cessation.  Sometimes,  however,  such  an  idea  may  continue  to  exert  a 
dominant  influence  over  the  whole  of  life ;  and  if  the  conduct  which  it  dictates 
should  pass  the  bounds  of  enthusiasm  or  eccentricity,  we  say  that  the  individual 
is  the  subject  of  Monomania.  The  nature  of  this  state  will  be  more  fully  con- 
sidered hereafter  (§  709). 

657.  The  same  view  may  be  fairly  applied,  also,  to  all  those  actions  performed 
by  us  in  our  ordinary  course  of  life,  which  are  rather  the  automatic  expressions 
of  the  ideas  which  may  be  dominant  in  our  minds  at  the  time,  than  prompted 
by  distinct  volitional  efforts  (§  647).  Of  this  kind,  the  act  of  expressing  the 

1  On  the  greater  number  of  the  foregoing  subjects,  much  curious  information  will  be 
found  in  Dr.  Hecker's  account  of  the  '  Dancing  Mania,'  forming  part  of  his  Treatise 
"On  the  Epidemics  of  the  Middle  Ages,"  translated  for  the  Sydenham  Society  by  Dr. 
Babington 


IDEO- MOTOR   ACTIONS:  —  EPIDEMIC   DELUSIONS.   591 

thoughts  in  language,  whether  by  speech  or  writing,  may  be  considered  as  a  good 
example ;  for  the  attention  may  be  so  completely  given-up  to  the  choice  of  words 
and  to  the  composition  of  the  sentences,  that  the  movements  by  which  these 
words  are  uttered  by  the  voice  or  traced  on  paper,  no  more  partake  of  the  truly 
volitional  character,  than  do  those  of  our  limbs  when  we  walk  through  the  streets 
in  a  state  of  Abstraction.  And  it  is  a  curious  evidence  of  the  influence  of 
Ideas,  rather  than  of  the  agency  of  the  Will,  in  producing  them,  that,  as  our 
conceptions  are  a  little  in  advance  of  our  speech  or  writing,  it  occasionally  hap- 
pens that  we  mis-pronounce  or  mis-spell  a  word,  by  introducing  into  it  a  portion 
of  some  other  whose  turn  is  shortly  to  come,  its  place  in  the  sentence  which  in 
in  process  of  formation  being  a  little  further  on ;  or  it  may  be  that  the  whole  oi 
the  anticipated  word  is  substituted  for  the  one  which  ought  to  have  been  ex 
pressed.  Now  it  is  obvious  that  there  could  be  neither  any  consciously-formed 
intention  of  breaking  the  regular  sequence,  nor  any  volitional  effort  to  do  so; 
and  the  result  is  evidently  due  to  the  superior  vividness  with  which  the  idea  of 
the  anticipated  word  is  present  to  the  mind,  as  compared  with  that  of  the  word 
which  the  course  of  construction  requires.  It  is  the  dominant  idea,  then,  which 
determines  the  movement,  the  Will  simply  permitting  it;  and  the  more  com- 
pletely the  Volitional  power  is  directed  to  other  objects,  the  more  completely 
automatic  are  the  actions  of  this  class.  They  may,  indeed,  come  to  be  performed 
even  without  the  consciousness,  or  at  least  without  the  remembered  consciousness, 
of  the  agent;  as  we  see  in  the  case  of  those  who  have  the  habit  of  'thinking 
aloud/  and  who  are  subsequently  quite  surprised  on  learning  what  they  have 
uttered.  The  one-sided  conversation  of  some  persons,  who  are  far  more  attentive 
to  their  own  trains  of  thought,  than  they  are  to  what  may  be  expressed  by  others, 
and  who  are  allowed  to  proceed  with  little  or  no  interruption,  is  often  a  sort  of 
k  thinking  aloud/  ' 

658.  Much  attention  has  recently  been  given  to  a  set  of  Involuntary  move- 
ments, which,  however  diverse  the   circumstances  under  which  they  occur,  all 
have  their  source  in  the  same  mental  condition,  —  that  of  expectant  attention  ; 
the  whole  Mind  being  possessed  with  the  Idea   that  a  certain  action  will  take 
place,  and  being  eagerly  directed  towards  the  indications  of  its  occurrence.     Such 
movements  are  well  known  to  occur  in  the  involuntary  muscles  connected  with 
the  Organic  functions,  which  receive  their  nervous  supply  from  the  Sympathetic 
system ;  and  they  are  among  the  means  by  which  important  modifications  are 
produced  in  those  functions  through  the  direction  of  the  mind  to  them.     (See 
Chap.  XV.) 

659.  But  it  is  with  the  Involuntary  movements  produced  by  the  same  agency 
through  the  Cerebro-spinal  system,  in  the  muscles  ordinarily  accounted  Volun- 
tary, that  we  are  at  present  specially  concerned.     This  is  a  very  curious  subject 
of  inquiry,  and  one  on  which  adequate  scrutiny  has  scarcely  yet  been  bestowed; 
the  phenomena  which  are  referable  to  the  principle  of  action  here  enunciated, 
having  been  very  commonly  explained  by  the  agency  of  some  other  force.     Thus, 
if  a  button  or  ring  be  suspended  from  the  end  of  the  finger  or  thumb,  in  such  a 
position  that,  when  slightly  oscillating,  it  shall  strike  against  a  glass  tumbler,  it 
has  been  affirmed  by  many  who  have  made  the  experiment,  that  the  button  con- 
tinues to  swim  with  great  regularity,  striking  the  glass  at  tolerably-regular  inter- 
vals, until  it  has  sounded  the  hour  of  the  day,  after  which  it  ceases  for  a  time 
to  swing  far  enough  to  make  another  stroke.     This  certainly  does  come  to  pass, 
in  many  instances,  without  any  intention  on  the  part  of  the  performer ;  who  may 
be  really  doing  all  in  his  power  to  keep  his  hand  perfectly  stationary.     Now  it 
is  impossible,  by  any  voluntary  effort,  to  keep  the  hand  absolutely  still,  for  any 
length  of  time,  in  the  position  required ;  an  involuntary  tremulousness  is  always 

1  This  was  pre-eminently  the  case  with  Coleridge,  whose  whole  life  was  little  else  than 
a  waking  dream,  and  whose  usual  talk  was  the  outpouring  of  his  dominant  ideas.  (Se* 
§  650). 


592  FUNCTIONS  OF   THE  CEREBRO-SPINAL  NERVOUS    SYSTEM. 

observable  in  the  suspended  body ;  and  if  the  attention  be  fixed  upon  the  part, 
with  the  expectation  that  the  vibrations  will  take  a  determinate  direction,  they 
are  very  likely  to  do  so.1  Their  persistence  in  this  direction,  however,  only  takes 
place  so  long  as  they  are  guided  by  tlie  visual  sensations  ;  a  fact  which  at  once 
points  to  the  real  spring  of  their  performance.  When  the  performer  is  impressed 
with  the  conviction  that  the  hour  will  be  thus  indicated,  the  result  is  very  likely 
to  happen ;  and  when  it  has  once  occurred,  his  confidence  is  sufficiently  esta- 
blished to  make  its  recurrence  a  matter  of  tolerable  certainty.  On  the  other 
hand,  the  experiment  seldom  succeeds  with  sceptical  subjects;  the  expectant  idea 
not  having  in  them  the  requisite  potency.  That  it  is  through  the  Mind  that 
these  movements  are  regulated,  however  involuntarily,  appears  evident  from  these 
two  considerations;  first,  that  if  the  performer  be  entirely  ignorant  of  the  hour, 
the  strokes  on  the  glass  do  not  indicate  its  number,  except  by  a  casual  coinci- 
dence ;  and  second,  that  the  division  of  the  entire  period  of  the  earth's  rotation 
into  twenty-four  hours,  and  the  very  nomenclature  of  these  hours,  being  entirely 
arbitrary  and  conventional,  cannot  be  imagined  to  operate  in  any  other  mode.2 
These  phenomena,  in  which  no  hypothetical  '  odylic '  or  other  concealed  agency 
can  be  reasonably  supposed  to  operate,  are  here  alluded-to  only  for  the  sake  of 
illustrating  those  next  to  be  described,  which  have  been  imagined  to  prove  the 
existence  of  a  new  force  in  Nature. 

660.  So,  again,  if  a  u  fragment  of  anything,  of  any  shape,"  be  suspended  from 
the  end  of  the  fore-finger  or  thumb,  and  the  attention  be  intently  fixed  upon  it, 
regular  oscillations  will  be  frequently  seen  to  take-place  in  it ;  and  if  changes  of 
various  kinds  be  made  in  the  conditions  of  the  experiment,  by  placing  bodies  of 
different  sorts  beneath  the  pendulum,  or  by  the  contact  of  different  persons  or 
things  with  the  person  of  the  suspender,  corresponding  changes  in  the  direction 
of  the  movements  will  very  commonly  follow.3  Now  this  will  occur,  notwith- 
standing the  strong  desire  of  the  experimenter  to  maintain  a  complete  immobility 
in  the  suspending  finger;  but  it  is  very  easily  proved  that  the  movements  are 
guided  by  his  visual  sensations,  and  that  the  impulse  to  them  is  entirely  derived 
from  his  expectation  of  a  given  result  For,  if  he  close  bis  eyes,  or  withdraw 
them  from  the  vibrating  body,  its  oscillations  (as  in  the  previous  case),  imme- 
diately lose  their  constancy;  manifestly  proving  that  the  influence  which  directs 
them  acts  through  his  consciousness.  And,  again,  if  he  be  ignorant  of  the 
change  which  is  made  in  the  conditions  of  the  experiment,  and  should  expect  or 
guess  something  different  from  that  which  really  exists,  the  movement  will  be  in 
accordance  with  his  idea,  not  with  the  reality.4 — Thus,  then,  we  have  here  a 

1  This  was  long  since  pointed  out  by  M.  Chevreul,  who  investigated  the  subject  in  a 
truly  philosophic  spirit.  See  his  letter  to  M.  Ampere,  in  the  "  Eevue  des  Deux-Mondes," 
Mai,  1833  ;  and  his  recent  treatise  "  De  la  Baguette  Divinatoire,  du  Pendule  dit  Explora- 
teur,  et  des  Tables  Tournantes,"  Paris,  1854. 

a  For  instance,  the  button  which  strikes  eleven  at  night  in  London,  should  strike  twenty- 
three  in  Rome,  where  the  cycle  of  hours  is  continued  through  the  whole  twenty-four  hours ; 
and  if  an  Act  of  Parliament  were  to  introduce  the  Italian  horary  arrangement  into  this 
country,  all  the  swinging  buttons  in  her  Majesty's  dominion  would  have  to  add  twelve  to 
their  number  of  post-meridiem  strokes ;  all  which  would  doubtless  come  to  pass  if  the 
experimenters'  faith  in  the  result  were  sufficiently  strong. 

3  See  Dr.  H.  Mayo  on  "  The  Truths  contained  in  Popular  Superstitions,"  3rd  edition, 
Letter  xii. 

4  A   most  remarkable  and  convincing  exemplification  of  this  fact,  is  afforded  by  Dr. 
Henry  Madden's  experiments  with  Mr.  Rutter's  "  Magnetometer,"  at  Brighton,  as  detailed 
in  the  "Lancet"  for  Nov.  15,  1851. — Dr.  Madden  had  satisfied  himself,  in  the  first  in- 
stance, that  the  vibrations  of  the  suspended  body  were  affected  by  the  reception,  into  his 
other  hand,  of  homoeopathic  globules,  whose  differences  of  composition  were  indicated  by 
corresponding  changes  in  the  direction  of  the  oscillations.     But  having  been  led  to  re-ex- 
amine the  question,  and  to  apply  that  test  which  he  ought  to  have  applied  from  the  first, — 
namely,  to  have  various  globules  put  into  his  hand,  without  being  himself  made  aware  of 
their  composition, — he  found  that  the  results  entirely  lost  their  previous  constancy,  which 
was  thus  evidently  due  to  his  expectation  of  a  particular  movement  in  each  case.     It  is  a 


IDEO-MOTOR  ACTIONS:  —  EXPECTANT  ATTENTION.     593 

most  distinct  proof  that  a  state  of  mind  exists,  which  is  neither  volitional  nor 
emotional,  but  which  consists  in  the  complete  engrossment  of  the  attention  by  a 
fixed  Idea;  whereby  definite  muscular  movements  are  produced,  in  spite  of  a 
determined  exertion  of  the  Will.  The  Will  is  concerned,  however,  in  the  in- 
duction of  the  mental  state  in  question,  by  the  fixation  of  the  attention  on  the 
oscillating  body;  and  it  is  only  in  those  individuals  who  possess  the  power  of 
voluntary  abstraction  (§  668)  to  a  considerable  extent,  that  the  experiment  is 
likely  to  succeed.  It  is  scarcely  necessary  to  add,  that  as  faith  in  its  results  is 
essential  to  their  production,  those  who  are  acquainted  with  the  mode  in  which 
they  are  really  brought-about,  are  not  likely  to  be  good  subjects  for  it. 

661.  It  is  doubtless  on  the  very  same  physiological  principle,  that  we  are  to 
explain  the  mysterious  phenomena  of  the  '  Divining-Rod/  which  have  been  ac- 
cepted as  true,  or  rejected  as  altogether  fabulous,  according  to  the  previous 
habits  of  thought  of  those  who  have  given  their  attention  to  the  subject.  Now, 
that  the  end  of  a  hazel-fork,  whose  limbs  are  grasped  firmly  in  the  hands  of  a 
person  whose  faith  can  scarcely  be  doubted,  frequently  points  upwards  or  down- 
wards without  any  intentional  direction  on  his  part,  and  often  thus  moves  when 
there  is  metal  or  water  beneath  the  surface  of  the  ground  at  or  near  the  spot,  is 
a  fact,  which  is  vouched-for  by  such  testimony,  that  we  have  scarcely  a  right  to 
reject  it;  and  when  we  come  to  examine  into  the  conditions  of  the  occurrence, 
we  shall  find  that  they  are  such  as  justify  us  in  attributing  it  to  a  state  of  expec- 
tant attention,  which  (as  we  have  seen)  is  fully  competent  to  induce  muscular 
movement.  For  in  the  first  place,  as  not  above  one  individual  in  forty,  even  in 
the  localities  where  the  virtues  of  the  divining-rod  are  still  held  as  an  article  of 
faith,  is  found  to  succeed  in  the  performance  of  this  experiment,  it  is  obvious 
that  the  agency,  whatever  be  its  nature,  which  produces  the  deflection,  must 
operate  by  affecting  the  holder  of  the  rod,  and  not  by  attracting  or  repelling  the 
rod  itself.  And  when  experiments  are  carefully  made  with  the  view  of  d(  ter- 
loining  the  nature  of  this  agency,  they  are  found  to  indicate  most  clearly  that  the 
state  of  l  expectant  attention/  induced  by  the  anticipation  of  certain  results,  is 
fully  competent  to  produce  them.  For  the  mere  act  of  holding  the  rod  for  some 
time  in  the  required  position,  and  of  attending  to  its  indications,  is  sufficient  to 
produce  a  tendency  to  spasmodic  contraction  in  the  grasping  muscles,  notwith- 
standing a  strong  effort  of  the  will  to  the  contrary ;  and  when,  by  such  contrac- 
tions, the  limbs  of  the  fork  are  made  to  approximate-towards  or  to  separate-from 
each  other,  the  point  of  the  fork  will  be  caused  to  move  either  upwards  or  down- 
wards, according  to  the  position  in  which  it  is  held.  If,  when  the  muscles  have 
this  tendency  to  contract,  occasioned  by  their  continued  restraint  in  one  position, 
the  mind  be  possessed  with  the  expectation  that  a  certain  movement  will  ensue, 
that  movement  will  actually  take-place,  even  though  a  strong  effort  may  be  made 
by  the  Will  to  prevent  any  change  in  the  condition  of  the  muscles.  And  a  suf- 
ficient ground  for  such  expectation  exists,  on  the  part  of  those  who  are  possessed 
with  the  idea  of  the  peculiar  powers  of  the  divining-rod,  in  the  belief,  or  even  in 
the  surmise,  that  water  or  metal  may  lie  beneath  particular  points  of  the  surface 
over  which  they  pass.1 — The  same  instrument  appears  to  have  been  used,  even 

manifestation  of  the  very  imperfect  analysis  -which  is  commonly  made  of  such  phenomena, 
that,  from  the  moment  when  they  are  found  referable  to  a  physiological  principle,  instead 
of  demonstrating  (as  they  were  at  first  supposed  to  do)  the  existence  of  a  new  force,  they 
seem  to  lose  all  their  interest  for  those  who  had  previously  watched  them  with  eager- 
ness, and  to  be  set  down  as  illusory,  or  as  the  product  of  the  'imagination  ;'  notwithstand- 
ing that  they  are  as  real  in  the  one  case  as  in  the  other,  and  are  not  in  any  degree  less 
curious  and  interesting  when  considered  under  the  former  aspect,  than  when  viewed  in  the 
latter. 

1  This  was  admitted  even  by  Dr.  H.  Mayo,  notwithstanding  his  belief  in  the  existence  of 
an  '  Od-force,'  governing  the  movements  of  the  divining-rod.  For  he  found  in  the  couree 
of  his  experiments,  that  when  his  '  diviner  '  knew  which  way  he  expected  the  fork  to  m  >ve, 
it  invariably  answered  his  expectations  ;  but  when  he  had  the  man  blindfolded,  the  results 


594  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

from  a  very  early  period,  by  those  who  were  supposed  to  possess  '  a  spirit  of 
divination/  for  the  purpose  of  giving  replies  to  questions  by  its  movements,  pre- 
cisely after  the  fashion  of  the  'talking  tables'  of  our  own  day,  the  hands  of  the 
operators  (where  they  really  believed  in  their  power,  and  were  not  impostors) 
being  automatically  impelled  to  execute  the  appropriate  movements  of  the  rod, 
by  their  idea  of  what  the  answer  should  be.1 

662.  No  difficulty  can  be  felt  by  any  one  who  has  been  led  by  the  preceding 
considerations  to  recognize  the  principle  of  'Ideo-Motor  actions/  in  applying  this 
principle  to  the  phenomena  of  *  Table-turning '  and  'Table-talking/  which, 
when  rightly  analysed,  prove  to  be  among  the  very  best  examples  of  the  reflex 
operations  of  the  Cerebrum,  that  are  exhibited  by  individuals  whose  state  of  mind 
can  scarcely  be  considered  as  abnormal.  The/acte,  when  stripped  of  the  invest- 
ment of  the  marvellous  with  which  they  have  too  commonly  been  clothed,  are 
simply  as  follows : — A  number  of  individuals  seat  themselves  round  a  table  on 
which  they  place  their  hands,  with  the  idea  impressed  on  their  minds  that  the 
table  will  move  in  a  rotatory  direction ;  the  direction  of  the  movement  to  the 
right  or  to  the  left,  being  generally  arranged  at  the  commencement  of  the  experi- 
ment. The  party  sits,  often  for  a  considerable  time,  in  a  state  of  expectation, 

•were  uncertain  and  contradictory.  Hence  he  became  certain  that  several  of  those  in 
•whose  hands  the  divining-rod  moves,  set  it,  in  motion,  and  direct  its  motion  (however  unin- 
tentionally and  unconsciously)  by  the  pressure  of  their  fingers,  and  by  carrying  their 
hands  nearer-to  or  apart-from  each  other.  (See  his  Letters  "  On  the  Truths  contained  in 
Popular  Superstitions,"  Letter  i.) — The  following  statement  of  the  results  obtained  by  a 
very  intelligent  friend  of  the  Author,  who  took-up  the  inquiry  some  years  ago,  with  a  strong 
prepossession  (derived  from  the  assurances  of  men  of  high  scientific  note)  in  favour  of  the 
reality  of  the  supposed  influence,  but  yet  with  a  desire  to  investigate  the  whole  matter 
carefully  and  philosophically  for  himself,  will  serve  as  a  complete  illustration  of  the  doc- 
trine enunciated  above.  Having  duly  provided  himself  with  a  hazel  fork,  he  set-out  upon 
a  survey  of  the  neighbourhood  in  which  he  happened  to  be  staying  on  a  visit ;  this  district 
was  one  known  to  be  traversed  by  mineral  veins,  with  the  direction  of  some  of  which  he 
was  acquainted.  With  his  '  divining-rod'  in  his  hand,  and  with  his  attention  closely  fixed 
upon  his  instrument  of  research,  he  walked-forth  upon  his  experimental  tour ;  and  it  was 
not  long  before,  to  his  great  satisfaction,  he  observed  the  point  of  the  fork  to  be  in  motion, 
at  the  very  spot  where  he  knew  that  he  was  crossing  a  metallic  lode.  For  many  less  cau- 
tious investigators,  this  would  have  been  enough  ;  but  it  served  only  to  satisfy  this  gentle- 
man that  he  was  a  favourable  subject  for  the  trial,  and  to  stimulate  him  to  further  inquiry. 
Proceding  in  his  walk,  and  still  holding  his  fork,  secundum  artem,  he  frequently  noticed  its 
point  in  motion,  and  made  a  record  of  the  localities  in  which  this  occurred.  He  repeated 
these  trials  on  several  consecutive  days,  until  he  had  pretty-thoroughly  examined  the 
neighbourhood,  going  over  some  parts  of  it  several  times.  When  he  came  to  compare  and 
analyse  the  results,  he  found  that  there  was  by  no  means  a  satisfactory  accordance 
amongst  them ;  for  there  were  many  spots  over  which  the  rod  had  moved  on  one  occasion, 
at  which  it  had  been  obstinately  stationary  on  others,  and  vice  versa  ;  so  that  the  constancy 
of  a  physical  agency  seemed  altogether  wanting.  Further,  he  found  that  whilst  some  of 
the  spots  over  which  the  rod  had  moved,  were  those  known  to  be  traversed  by  mineral 
veins,  there  were  many  others  in  which  its  indications  had  been  no  less  positive,  but  in 
which  those  familiar  with  the  mining  geology  of  the  neighbourhood  were  well  assured 
that  no  veins  existed.  On  the  other  hand,  the  rod  had  remained  motionless  at  many 
points  where  it  ought  to  have  moved,  if  its  direction  had  been  affected  by  any  kind  of  ter- 
restrial emanation.  These  facts  led  the  experimenter  to  a  strong  suspicion  that  the  cause 
existed  in  himself  alone ;  and  carrying-out  his  experiments  still  further,  he  ascertained 
that  he  could  not  hold  the  fork  in  his  hand  for  many  minutes  consecutively,  concentrating 
his  attention  fixedly  upon  it,  without  an  alteration  in  the  direction  of  its  point,  in  conse- 
quence of  an  involuntary  though  almost  imperceptible  movement  of  his  hands ;  so  that  in 
the  greater  number  of  instances  in  which  the  rod  exhibited  motion,  the  phenomenon  was 
clearly  attributable  to  this  cause,  and  it  was  a  matter  of  pure  accident  whether  the  move- 
ment took-place  over  a  mineral  vein,  or  over  a  blank  spot.  But  further,  he  ascertained 
on  a  comparison  of  his  results,  that  the  movement  took-place  more  frequently  where  he 
knew  or  suspected  tha  existence  of  mineral  veins,  than  in  other  situations ;  and  thus  h* 
came,  without  any  knowledge  of  the  theory  of  expectant  attention,  to  the  practical  conclu- 
sion Hiat  the  actions  of  his  nerves  and  muscles,  wer<j  iu  great  decree  regulated  by  the 
ideas  which  possessed  his  mind. 

1  See  Chevreul,  Op.  cit.,  premiere  partie. 


IDEO-MOTOR  ACTIONS: — EXPECTANT  ATTENTION.      595 

•with  the  whole  attention  fixed  upon  the  table,  and  looking  eagerly  for  the  first  sign 
of  the  anticipated  motion.     Generally  one  or  two  slight   changes  in  its  place 
herald  the  approaching  revolution  j  these  tend  still  more  to  excite  the  eager  atten- 
tion of  the  performers,  and  then  the  actual  (  turning '  begins.     If  the  parties 
retain  their  seats,  the  revolution  only  continues  as  far  as  the  length  of  their  arms 
will  allow;  but  not  unfrequently  they  all  rise,  feeling  themselves  obliged  (as 
they  assert)  to  follow  the  table ;  and  from  a  walk,  their  pace  may  be  accelerated 
to  a  run,  until  the  table  actually  spins-round  so  fast  that  they  can  no  longer  keep- 
up  with  it.     All  this  is  done,  not  merely  without  the  least  consciousness  on  the 
part  of  the  performers  that  they  are  exercising  any  force  of  their  own,  but  for    < 
the  most  part  under  the  full  conviction  that  they  are  not. — Now  the  rationale  of 
these  and  other  phenomena  of  a  like  kind,  is  simply  as  follows.     The  continued 
concentration  of  the  attention  upon  a  certain  Idea  gives  it  a  l  dominant '  power 
not  only  over  the  mind,  but  over  the  body  \  and  the  muscles  become  the  involun- 
tary instruments  whereby  it  is  carried  into  operation.     In  this  case,  too,  as  in 
that  of  the  divining-rod,  the  movement  is  favoured  by  the  state  of  muscular  ten- 
sion, which  ensues  when  the  hands  have  been  kept  for  some  time  in  a  fixed 
position.     And  it  is  by  the  continued  influence  of  the  'dominant  idea/  that 
the  performers  are  impelled  to  follow  (as  they  believe)  the  revolution  of  the  table, 
which  they  really  sustain  by  their  continued  propulsion.     However  conscienti- 
ously they  may  believe  that  the  attraction  of  the  table  carries  them  along  with 
it,  instead  of  an  impulse  which  originates  in  themselves  pushing  along  the  table, 
yet  no  one  feels  the  least  difficulty  in  withdrawing  his  hand,  if  he  really  wills  to 
do  so.     But  it  is  the  characteristic  of  the  state  of  mind  from  which  ideo-motor 
actions  proceed,  that  the  volitional  power  is  for  the  time  in  abeyance ;  the  whole 
mental  power  being  absorbed  (as  it  were)  in  the  high  state  of  tension  to  which 
the  ideational  consciousness  has  been  wrought-up.     To  this   rationale,  all   the 
results  of  the  variations  that  have  been  from  time  to  time  introduced  into  the 
experiment,  are  perfectly  conformable;  it  having  been  always  found,  that  when 
any  method  was  employed  under  the  conviction  that  the  process  would  be  favoured 
by  it  (as  when,  during  the  reign  of  the  electrical  hypothesis,  the  feet  of  the 
table  were  insulated,  or  a  continuous  circuit  was  made  by  the  hands  of  the  per- 
formers), the  expectation  thus  excited  brought-about  the  result  at  an  earlier 
period  than  usual.1 

663.  The  application  of  the  same  principle  to  the  ordinary  phenomena  of 
'Table-talking'  is  so  obvious  as  to  need  no  lengthened  exposition.  There  can 
be  no  reasonable  doubt  that  these  phenomena  have  been  manifested  in  a  large 
number  of  instances,  through  the  agency  of  individuals  who  would  not  wilfully 
be  parties  to  deception  of  any  kind ;  and  that  the  movements  which  they  invol- 
untarily gave  to  the  tables,  were  the  expressions  of  the  ideas  with  which  their 
own  minds  were  possessed,  as  to  what  the  answers  should  be  to  the  questions 
propounded.2  It  is  asserted,  however,  that  the  c  talking-tables '  often  give  true 

1  The  demonstration  that  the  table  really  is  moved  by  the  hands  placed  upon  it,  not- 
withstanding the  positive  conviction  of  the  performers  to  the  contrary,  was  first  afforded 
by  the  very  ingenious  « indicator '  devised  by  Prof.  Faraday ;  which  showed  that  lateral 
pressure  is  always  exercised,  however,  unconsciously,  before  the  movement  commences ; 
and  that  if  by  keeping  their  eyes  upon  the  index,  the  performers  check  the  first  tendency 
to  exert  such  pressure,  the  table  never  gives  the  least  sign  of  movement. — Prof.  Faraday 
did  not  in  his  well-known  Letter  on  this  subject  ("  Athenaeum,"  July  2,  1853),  offer  any 
physiological  rationale  of  this  unconscious  muscular  action ;  but  referred  for  it  to  "  the 
Discourse  delivered  by  Dr.  Carpenter  at  the  Royal  Institution,  March  12,  1852,  'On 
the  influence  of  Suggestion  in  modifying  and  directing  Muscular  Movement  independently 
of  Volition,"  in  which  the  doctrine  of  Ideo-motor  action  had  been  for  the  first  time  pub- 
licly enunciated. 

*  This  must  be  perfectly  clear  to  those  who  will  read  with  candour  the  various  publica- 
tions of  their  experience  with  '  talking  tables,'  put- forth  by  the  Revds.  N.  S.  Godfrey, 
E.  Gillson,  R.  W.  Dibdin,  and  other  clergymen,  who  had  adopted  the  idea  that  they  com- 
municated through  these  means  with  Evil  Spirits,  or  even  with  Satan  himself.  A  more 
detailed  analysis  of  this  and  other  kindred  subjects  than  the  present  work  affords  space 
for,  will  be  found  in  the  "Quarterly  Review,"  Sept.,  1853. 


506  FUNCTIONS   Of   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

answers  to  questions  proposed  to  them  as  to  matters  of  fact,  though  none  of  the 
parties  present  may  have  any  knowledge  of  what  the  answers  should  be ;  but 
this,  if  it  be  really  so,  is  not  only  far  from  being  opposed  to  the  Physiological 
doctrines  here  advanced,  but  affords  a  curious  illustration  and  extension  of  them. 
For,  as  there  is  no  doubt  that  impressions  once  made  upon  our  consciousness, 
though  subsequently  entirely  lost  to  it,  may  direct  our  trains  of  thought  in 
Delirium  and  Dreaming,  or  may  even,  as  in  Somnambulism,  govern  our  actions, 
so  does  it  seem  quite  reasonable  to  attribute  the  muscular  movements  by  which 
the  table  is  made  to  answer,  to  impressions  left  by  past  ideas  upon  the  Cerebrum, 
on  which  it  reacts,  by  an  operation  analogous  to  the  '  unconscious  cerebration  ' 
already  described  (§  653),  so  as  to  work-out  results  through  the  muscular  system, 
of  whose  source  within  himself  the  operator  is  as  ignorant  as  he  is  of  his  exercise 
of  nerve-force  in  calling  the  muscles  into  contraction.1  The  truth  of  this  view 
has  been  tested  by  experiments  so  varied  as  to  exclude  all  possibility  of  influence 
from  such  '  latent  ideas ;'  and  it  has  been  then  found  that  the  table  could  reveal 
nothing  whatever. 

664.  To  this  same  category  are  doubtless  to  be  referred  a  large  number  of 
those  actions  of  Mesmeric  '  subjects/  which  have  been  considered  by  some  as 
most  unequivocal  indications  of  the  existence  of  an  agency  sui  generis,  whilst  by 
others  they  have  been  regarded  as  the  results  of  intentional  deception.     Many 
of  them  are  of  a  kind  which  the  Will  could  not  feign,  being  violent  convulsive 
movements,  such  as  no  voluntary  effort  could  produce ;  but  the  Mesmeric  '  sub- 
ject' being  previously  possessed  with  the  expectation  that  certain   results  will 
follow  certain  actions  (as,  for  instance,  that  convulsive  movements  will  be  brought- 
on  by  touching  a  piece  of  mesmerised  metal),  and  the  whole  nervous  power  being 
concentrated,  as  it  were,  upon  the  performance,  the  movements  follow  when  the 
subject  believes  the  conditions  to  have  been  fulfilled,  whether  they  have,  been,  or 
not.     These  facts  were  most  completely  established  by  the  Commission  appointed 
to  investigate  the  pretensions  of  Mesmer  himself;  and  whilst  they  demonstrate 
the  unreality  of  the  supposed  mesmeric  influence  (so  far,  at  least,  as  this  class 
of  phenomena  is  concerned),  they  also  prove  the  position  here  contended-for, 
namely,  the  sufficiency  of  the  state  of  expectant  attention,  in  those  whose  minds 
can  be  completely  possessed  by  it,  to  produce  effects  of  the  same  nature  with 
those  which  are  induced  in  Hysterical  subjects  by  emotional  excitement.     (See 
§  696). 

665.  Determining  Power  of  Volition. — We  have  now,  in  the  last  place,  to 
enquire  into  the  mode  in  which  Volition  operates  in  determining  the  course  of 
Thought  and  the  regulation  of  the  Conduct; — a  problem  of  extreme  difficulty, 
the  entire  solution  of  which  may  not  lie  within  the  limited  sphere  of  Man's 
present  capacity.     The  chief  subject  of  embarrassment,  however,  is  rather  the 
nature  and  source  of  the  Will  itself,  than  the  conditions  of  its  operation ;  for 
whilst  a  careful  analysis  of  our  own  consciousness  throws  much  light  on  the  latter, 

1  The  following  is  a  remarkable  example  of  this  kind  of  action,  which  is  detailed  in  the 
Rev.  R.  W.  Dibdin's  Lecture  on  Table-turning. — A  gentleman  who  was  at  the  time  a 
believer  in  the  '  spiritual'  agency  of  his  table,  supposed  himself  to  be  in  communication 
with  Edward  Young,  the  poet.  The  spirit  having  been  desired  to  prove  his  identity  by 
citing  a  line  of  his  poetry,  the  table  rapped-out  "Man  was  not  made  to  question,  but 
adore."  Being  asked  whether  the  line  was  in  the 'Night  Thoughts,'  the  spirit  replied 
(through  the  table)  "No."  "Where  is  it  then?"  The  reply  was  "Job."  Not  being 
familiar  with  Young's  Poems,  the  questioner  did  not  know  what  this  meant ;  but  the  next 
day  he  bought  a  copy  of  the  book  ;  and  at  the  end  of  the  Night  Thoughts  he  found  a 
Paraphrase  on  Job,  the  last  line  of  which  is  that  just  cited.  Of  course  he  was  very  much 
astonished  that  this  should  have  been  enunciated  by  the  table :  but  some  time  afterwards, 
he  found  that  he  had  had  the  book  in  his  house  all  the  time,  and  that  he  had  read  it  be- 
fore ;  so  that  the  remarkable  line  with  which  the  Paraphrase  of  Job  closes,  had  doubtless 
left  behind  it  a  cerebral  impression,  which,  being  called  into  activity  by  an  appropriate 
suggestion,  occasioned  the  same  effect  upon  his  muscular  movements,  as  if  the  remembrance 
of  it  had  been  actually  present  to  his  consciousness. 


DETERMINING    POWER     OF    VOLITION.  597 

the  scientific  investigation  of  the  former  has  seemed  to  lead  to  results  which  aie 
inconsistent  with  our  intuitive  conviction  of  freedom,  as  well  as  with  our  scarcely 
less  intuitive  notion  of  moral  responsibility.  Dismissing  the  former  question, 
therefore,  as  one  which  requires  a  much  more  laboured  discussion  than  could 
here  be  appropriately  bestowed  upon  it,  we  may  apply  ourselves  to  the  considera- 
tion of  the  mode  in  which  Volition  acts  (1)  upon  the  Corporeal  organism,  and 
(2)  upon  our  Psychical  nature. 

666.  It  is  a  fact  of  universal  experience,  that,  although  certain  states  of  Mind 
have  a  remarkable  influence  on  the  Organic  functions,  no  change  in  their  usual 
course  can  be  determined  by  the  direct  influence  of  the  Will.1     The  only  sensi- 
ble effect  which  the  strongest  effort  of  Volition  can  produce  on  the  bodily  frame, 
is  the  excitation  of  muscular  contraction.     Now  if  we  examine  into  the  cause  of 
a  Volition-al2  movement,  we  find  it  to  lie,  as  in  other  instances,  in  a  certain  com- 
bination of  material  conditions  with  dynamical  agency  (§  585).     The  aggregate 
of  the  material  conditions  is  a  state  of  integrity  of  the  Muscular  and  Nervous 
apparatus  through  which  the  Will  operates ;  the  dynamical  agency  is  the  effort 
which  we  are  conscious  of  putting-forth,  and  which  we  feel  to  be  the  power  by 
which  the  work  is  done ;  the  degree  of  volitional  exertion  required  being  strictly 
proportional  to  the  amount  of  resistance  to  be  overcome,  and  being  followed  by  a 
corresponding  sense  of  fatigue,  which  is  the  indication   of  the  expenditure  of 
force.     As  already  pointed-out  (§  625),  it  is  an  essential  condition  of  every  Vo- 
litional action,  that  a  distinct  idea  should  exist  of  the  object  to  be  attained,  and 
that  there  should  be  also  a  belief  in  the  possibility  of  attaining  it  by  the  means 
employed ;  and  further,  that  the  amount  of  power  which  can  be  put-forth  on  any 
occasion,  is  dependent,  cseteris  paribus,  upon  the  degree  in  which  the  attention 
is  concentrated  upon  the  eifort,  and  the  mind  withdrawn  from  the  contemplation 
of  other  objects.     Hence  it  is  (as  was  there  shown),  that  Emotional  excitement 
may  either  intensify  or  may  paralyse  the  Volitional  power,  according  as  it  deter- 
mines or  interferes-with  the  special  direction  of  the  mental  energy  to  the  object 
with  which  it  is  connected.     But  the  same  influence  is  capable  of  being  exerted 
by  the  simple  dominance  of  ideas,  in  certain  states  of  mind  in  which  the  direct- 
ing power  of  the  Will  over  the  current  of  thought  is  altogether  suspended,  with- 
out the  destruction  of  the  capacity  for  voluntary  exertion  of  the  nervo-muscular 
apparatus.     Thus  the  Author  has  seen  a  man  remarkable  for  the  poverty  of  his 
muscular  development,  who  shrank  from  the  least  exertion  in  his  ordinary  state, 
lift  a  28-lb.  weight  upon  his  little  finger  alone,  and  swing  it  round  his  head  with 
the  greatest  facility,  when  in  that  state  of  artificial  somnambulism  termed  Hyp- 
notism by  Mr.  Braid  (§  695) ;  his  extraordinary  command  of  muscular  power  in 
this  condition,  being  simply  due  to  the  complete  concentration  of  his  mental 
energy  upon  the  one  object,  and  to  the  dominance  of  the  idea  (with  which  his 
mind  was  possessed   by  the  confident  assurances  of  Mr.  Braid)  that  he  could 
attain  it  with  the  greatest  facility, — that  idea  not  being  negatived  by  his  ordinary 
experience,  for  reasons  to  be  presently  stated  (§  670).     On  the  other  hand,  the 
same  individual  (whilst  in  the  hypnotic  state)  declared  himself  altogether  unable 
to  raise  a  handkerchief  from  the  table,  after  many  apparently  strenuous  efforts  j 

1  "Which  of  you,  by  taking  thought,  can  add  one  cubit  to  his  stature?"  "Thou  canst 
not  make  one  hair  white  or  black." 

a  The  term  volitional  was  some  years  since  suggested  by  Dr.  Symonds,  in  an  excellent 
essay  on  the  'Connection  between  Mind  and  Muscle,'  published  in  the  "West  of  England 
Journal,"  1835,  as  expressing  more  emphatically  than  voluntary  the  characters  of  an 
action  proceeding  from  a  distinct  choice  of  the  object,  and  from  a  determinate  effort  to 
attain  it.  The  word  voluntary  may  perhaps  be  applied  to  that  wider  class  of  actions,  in 
which  there  is  no  very  distinct  choice  or  conscious  effort,  but  in  which  the  movement  flows 
as  it  were  spontaneously  from  the  antecedent  mental  state ;  the  consciousness,  however, 
being  fully  awake  to  its  performance,  and  the  will  being  brought  to  bear  detcrminately 
upon  it,  whenever  an  opposing  motive  tends  to  check  the  process  or  to  alter  its  direction. 
See  647. 


598  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

bis  mind  having  been  previously  possessed  by  the  assurance,  that  its  weight  wag 
too  great  for  him  to  move.1  In  that  curious  state  of  artificial  Reverie,  which  haa 
recently  attracted  much  attention  under  the  inappropriate  name  of  '  Electro- 
Biology'  (§  672),  precisely  the  same  phenomena  may  be  observed ;  the  subjects 
of  it  being  prevented  from  performing  the  commonest  voluntary  movements,  by 
the  assurance  that  they  cannot  execute  them,  which  assurance  takes  full  possession 
of  their  minds,  in  virtue  of  their  want  of  power  to  bring  their  ordinary  experi- 
ence to  bear  upon  the  idea  thus  introduced;  whilst  they  may  be  compelled,  by 
the  dominance  of  ideas  introduced  in  like  manner  by  external  suggestion,  to 
perform  actions,  which,  if  not  physically  impossible  to  them  in  their  ordinary 
Btate,  they  could  not  be  induced  to  execute  by  any  conceivable  motives. 

667.  These  facts  are  not  so  far  removed  from  our  ordinary  experience  as  might 
at  first  sight  appear.  For  it  must  be  within  the  knowledge  of  every  one,  that, 
when  first  attempting  to  perform  some  new  kind  of  action,  the  power  we  feel 
capable  of  exerting  depends  in  great  measure  upon  the  degree  of  our  assurance 
of  success.  Of  this  we  have  a  good  example  in  the  process  of  learning  to  swim; 
which  is  greatly  facilitated,  as  Dr.  Franklin  pointed-out,  by  our  first  taking 
means  to  satisfy  ourselves  of  the  buoyancy  of  our  bodies  in  the  water,  by  attempt- 
ing to  pick  up  an  object  from  the  bottom.  And  every  one  is  aware  of  the  assist- 
ance derived  from  the  encouragement  of  others,  when  we  are  ourselves  doubtful 
of  our  powers ;  and  of  the  detrimental  influence  of  discouragement  or  suggested 
doubt,  even  when  we  previously  felt  a  considerable  confidence  of  success.2  These 

1  The  Author  has  every  reason  to  believe  that  the  personal  character  of  this  individual 
placed  him  above  the  suspicion  of  deceit;  and  it  is  obvious  that  if  he  had  practised  the 
first  of  the  above  performances  (which  very  few,  even  of  the  strongest  men,  could  accom- 
plish without  practice),  the  effect  would  have  been  visible  in  his  muscular  development. 
Of  course,  there  was  not  an  equal  proof  of  the  absence  of  deception  in  the  second  case  as 
in  the  first:  but  if  the  reality  of  the  first,  and  the  validity  of  the  explanation  above  given, 
be  admitted,  there  need  be  no  difficulty  in  the  reception  of  the  second,  since  it  is  only 
another  manifestation  of  the  same  mental  condition. — Of  the  almost  superhuman  strength 
and  agility  with  which  the  body  seems  endowed,  when  the  whole  energy  is  concentrated 
upon  some  nervo-muscular  effort,  especially  under  the  influence  of  an  overpowering 
emotion,  the  following  remarkable  example  has  been  communicated  to  the  Author  by  a 
gentleman  on  whom  he  can  place  full  reliance,  and  who  was  personally  cognizant  of  the 
fact.  An  old  cook-maid,  tottering  with  age,  having  heard  an  alarm  of  fire,  seized  an 
enormous  box  containing  her  whole  property,  and  ran  down  stairs  with  it,  as  easily  as  she 
would  have  carried  a  dish  of  meat.  After  the  fire  had  been  extinguished,  she  could  not 
lift  the  box  a  hair's  breadth  from  the  ground,  and  it  required  two  men  to  convey  it  up- 
stairs again. 

a  The  Auth6*r  well  remembers,  several  years  ago,  being  among  those  who  tested  the 
validity  of  the  statement  put-forth  in  Sir  D.  Brewster's  "  Natural  Magic,"  that  four  per- 
sons can  lift  a  full-sized  individual  from  the  ground,  high  into  the  air,  with  the  greatest 
facility,  if  they  all  take-in  a  full  breath  previously  to  the  effort,  the  person  lifted  doing  the 
same.  He  could  readily  understand,  upon  physiological  principles,  that  a  full  inspiration 
on  the  part  of  the  lifters  would  have  a  certain  degree  of  efficacy  in  augmenting  their  nervo- 
muscular  power ;  but  he  could  not  perceive  how  the  performance  of  the  same  act  by  the 
person  lifted  could  have  any  appreciable  effect ;  and  while  many  of  his  acquaintances 
assured  him  that,  when  all  the  conditions  were  duly  observed,  the  body  went  up  '  like  a 
feather,'  and  that  they  felt  satisfied  of  being  able  to  support  it  upon  the  points  of  their 
fingers,  he  found  his  own  experience  quite  different ;  and  came  to  the  conclusion,  after 
much  observation,  that  the  facility  afforded  by  this  method  entirely  depended  upon  the 
degree  in  which  it  fulfilled  the  above-mentioned  conditions,  namely,  the  fixation  of  the 
attention  upon  the  effort,  and  the  conviction  of  the  success  of  the  method.  Whenever  the 
attention  was  distracted  and  confidence  weakened  by  scepticism  as  to  the  result,  the  pro- 
mised assistance  was  not  experienced. — The  Author  may  also  mention,  as  a  very  charac- 
teristic illustration  of  the  same  principle,  the  following  little  circumstance  communicated  to 
him  by  a  friend.  This  gentleman  related  that,  having  been  accustomed  in  his  boyhood  to 
play  at  bagatelle  with  other  juniors  of  his  family,  the  party  was  occasionally  joined  by  a 
relative  who  was  noted  for  her  success  at  the  game,  and  who  was  consequently  much 
dreaded  as  an  opponent ;  and  that,  on  one  occasion,  when  she  was  about  to  take  her  turn 
against  him,  he  roguishly  exclaimed,  "Now,  aunty,  you  will  not  be  able  to  make  a  hit;" 
the  effect  of  which  suggestion  was,  that  she  missed  every  stroke, — and  not  only  at  that 
Miru,  but  through  the  remainder  of  the  evening. 


DETERMINING    POWER    OF    VOLITION.  599 

familiar  facts  show  us,  therefore,  that  the  phenomena  just  described  as  occurring 
in  abnormal  states,  are  in  no  respect  contrary  to  our  knowledge  of  the  conditions 
under  which  the  Will  operates  in  producing  muscular  movement ;  but  afford, 
when  rightly  interpreted,  a  strong  confirmation  of  the  statements  already  made 
respecting  the  nature  of  those  conditions. 

668.  The  Will  is  exerted,  however,  not  merely  in  determining  the  actions  of 
the  body,  but  also  in  regulating  the  operations  of  the  Mind ;  and  here,  again,  we 
find  that  its  action  is  limited  by  certain  conditions,  the  knowledge  of  which  is  of 
great  importance.     It  may  be  said,  generally,  that  we  have  no  direct  power  of 
calling  before  our  consciousness,  by  a  volitional  effort,  ideas  which  are  not  already 
present  there  ;  thus,  in  the  act  of  Recollection,  we  can  do  no  more  than  fix  our 
minds  upon  those  ideas  which  seem  most  likely  to  recall,  by  an  act  of  suggestion, 
the  one  which  we  desiderate  (§  644).     But  what  we  do  possess,  is  the  power  of 
excluding  some  ideas,  and  of  bringing  others  prominently  before  our  mental 
vision ;  and  this  by  the  power  of  Voluntary  Attention,  which  is  the  chief,  if  not 
the  sole,  means  through  which   the  sequence  of  our  thoughts  is  directed  by  the 
Will.     It  has  been  already  pointed-out,  that  the  Attention  may  be  involuntarily 
fixed  upon  certain   subjects  of  consciousness,  through  the  attraction   they  exert 
upon  the  individual  mind,  in  virtue  either  of  its  original  constitution  or  of  its 
acquired  habitudes ;  and  that  this  attraction  determines  much  of  the  automatic 
action  of  our  faculties  (§  647).     When  most  strongly  exerted,  it  causes  the  con- 
sciousness to  be  so  completely  engrossed  by  one  train  of  ideas,  that  the  mind  is, 
for  the  time,  incapable  of  any  other  ideational  change :  sensory  impressions,  if 
felt,  not  being  perceived;  and,  where  the  consciousness  is  most  completely  con- 
centrated upon  the  internal  operations,  the  individual  being  as  insensible  to  exter- 
nal impressions  as  if  he  were  in  a  profound  sleep.     But  these  automatic  tenden- 
cies of  the  mind  may  be  to  a  certain  extent  antagonized  by  the  Will,  which  keeps 
them  in  check  (just  as  it  restrains  many  of  the  automatic  impulses  to  bodily 
movement)  by  the  special  power  which  it  exerts  over  the  Attention.     This  it  can 
detach  from  subjects  which  have  at  the  time  the  greatest  attractiveness  for  it,  and 
can  forcibly  direct  it  to  others  from  which  their  attraction  would  otherwise  divert 
it.     And  in  its  most  complete  and  powerful  exercise  (which  is  not  within  the 
capacity  of  every  one),  it  can  so  completely  limit  the  mind  to  one  train  of  thought, 
that  the  state  of  Abstraction  induced  by  the  Will  may  be  as  complete  as  that 
which  in  some  individuals  is  of  spontaneous  occurrence  (§  671). 

669.  In  proportion  as  we  are  able  thus  to  concentrate  our  attention  on  the  sub- 
ject proper  to  the  time,  and  to  exclude  all  distracting  considerations  jphilst  pursu- 
ing the  trains  of  thought  which  the  contemplation  of  it  suggests,  will  oe  our  power 
of  advantageously  employing  our  Intellectual  Faculties  in  the  acquirement  of 
knowledge  and  in  the  pursuit  of  truth;  and  all  men  who  have  been  distinguished 
by  their  intellectual  achievements,  have  possessed  this  faculty  in  a  considerable 
degree.     It  is  one  which  is  "  eminently  capable  of  cultivation  by  steady  intention 
of  mind  and  habitual  exercise ;"  and  the  more  frequently  it  is  put  in  practice,  the 
easier  the  exercise  becomes.     In  fact,  when  a  man  has  once  brought  his  Intellec- 
tual faculties  under  the  mastery  of  his  Will,  to  such  an  extent  as  to  induce  the 
state  of  Abstraction  whenever  he  pleases,  this  state  becomes  (as  it  were)  '  second- 
arily automatic ;'  and  the  fixed  direction  of  the  thoughts,  which  at  first  required 
a  constant  volitional  effort  for  its  maintenance,  comes  to  be  continued  without  any 
consciousness  of  exertion,  so  long  as  the  Will  may  permit. — We  have  in  our  own 
consciousness  of  effort,  and  in  our  experience  of  subsequent  fatigue,  a  very  strong 
indication  that  the  power  which  thus  controls  and  directs  the  current  of  thought, 
is  of  the  same  kind  with  that  which  calls-forth  Volitional  movements  of  the  body, 
though  exerted  in  a  different  mode.     And  just  as  the  strongest  exertion  of  Will 
is  required  to  produce  or  sustain  Muscular  contraction,  when  the  sense  of  muscu- 
lar fatigue  is  already  strongly  experienced,  or  when  we  are  antagonizing  a  power- 
ful automatic  impulse,  so  in  the  determination  of  Mental  effort  in  a  particular 


600  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOUS    SYSTEM. 

direction,  we  find  ourselves  necessitated  to  make  the  greatest  Volitional  effort 
when  we  are  already  labouring  under  the  sense  of  Cerebral  fatigue,  or  when  the 
attention  is  powerfully  solicited  by  some  other  attractive  object.  And  it  is  after 
any  such  contest  with  our  natural  tendencies,  that  we  experience  the  greatest, 
degree  of  exhaustion ;  the  merely  automatic  action  of  the  Mind,  which  is  attended 
with  no  effort,  being  followed  by  comparatively  little  fatigue.1 

670.  But  this  determining  power  of  Volition  is  employed,  in  however  slight  a 
degree,  whenever  the  succession  of  thought  is  not  perfectly  spontaneous;*  when- 
ever, in  fact,  we  wish  our  consciousness  to  take  a  particular  direction,  even  for 
the  apprehension  of  ideas  most  familiar  to  our  minds.  And  it  is  especially  re- 
quisite for  the  exercise  of  the  Judyment,  since  the  comparison  of  ideas  which 
this  involves,  can  only  take  place  when  the  Will  has  the  power  of  selecting  those 
which  are  appropriate,  and  of  bringing  them  into  collocation  with  each  other. 
The  continual  action  of  the  judgment  through  this  medium,  is  in  fact  the  source 
of  that  common-sense,  whereon  we  rely  in  the  ordinary  conduct  of  life.  We 
almost  unconsciously  store-up  a  mass  of  impressions  derived  from  our  habitual 
experience,  by  which  we  are  continually  testing  the  validity  of  new  impressions; 
admitting  them  if  consonant  with  it,  rejecting  them  if  vehemently  discordant, 
and  keeping  them  on  trial  if  we  cannot  dispose  of  them  in  one  or  other  of  these 
modes.  The  simple  credulity  of  the  child,  on  the  other  hand,  depends  upon  his 
having  no  such  stock  of  experience  on  which  to  fall  back,  for  the  correction  of 
any  erroneous  notions  which  he  may  himself  form,  or  which  may  be  imparted  to 
him  by  others.  The  effort  required  for  this  comparison  of  things  present  with 
past  experience,  when  once  it  comes  to  be  habitual,  is  so  slight  as  to  be  scarcely 
perceptible  even  to  one's  self;  yet  slight  as  the  effort  may  be,  it  is  the  one  thing 
needful ;  and  it  may  be  unhesitatingly  laid-down,  that,  if  the  directing  powers  of 

1  The  Author  is  satisfied  from  his  own  experience,  that  a  most  valuable  indication  may  be 
hence  drawn,  in  regard  to  the  regulation  of  the  habits  of  Intellectual  labour.  To  individ- 
uals of  ordinary  mental  activity,  who  have  been  trained  in  the  habit  of  methodical  and  con- 
nected thinking,  a  very  considerable  amount  of  work  is  quite  natural;  and  when  such  per- 
sons are  in  good  bodily  health,  and  the  subject  of  their  labour  is  congenial  to  them, — espe- 
cially if  it  be  one  that  has  been  chosen  by  themselves,  as  furnishing  a  centre  of  attraction 
around  which  their  thoughts  spontaneously  tend  to  range  themselves, — their  intellectual 
operations  require  but  little  of  the  controlling  or  directing  power  of  the  Will,  and  may  be 
continued  for  long  periods  together  without  fatigue.  But  from  the  moment  when  an  indis- 
position is  experienced  to  keep  the  attention  fixed  upon  the  subject,  and  the  thoughts  wan- 
der from  it  unless  coerced  by  the  Will,  the  mental  activity  loses  its  spontaneous  or  automa- 
tic character;  and  more  exertion  is  required  to  maintain  it  volitionally  during  a  brief 
period,  and  nibre  fatigue  is  subsequently  experienced  from  such  an  effort,  than  would  be 
involved  in  the  continuance  of  an  automatic  operation  through  a  period  many  times  as 
long.  Hence  he  has  found  it  practically  the  greatest  economy  of  mental  labour,  to  work 
vigorously  when  he  feels  disposed  to  do  so,  and  to  refrain  from  exertion,  so  far  as  possible, 
when  it  is  felt  to  be  an  exertion. — Of  course  this  rule  is  not  applicable  to  all  individuals,  for 
there  are  some  who  would  pass  their  whole  time  in  listless  inactivity  if  not  actually  spurred- 
on  by  the  feeling  of  necessity;  but  it  holds  good  for  those  who  are  sufficiently  attracted 
by  objects  of  interest  before  them,  or  who  have  in  their  worldty  circumstances  a  suffi- 
ciently strong  motive  to  exertion,  to  make  them  feel  that  they  must  work ;  the  question 
with  them  being,  how  they  can  attain  their  desired  results  with  the  least  expenditure  of 
mental  effort. 

a  It  is  hoped  that  the  reader  will  have  been  made  sufficiently  aware  by  the  preceding 
explanations,  that  by  the  terms  '  spontaneous '  or  '  automatic '  succession  of  thought,  it  is 
intended  to  designate  that  sequence  of  states  of  consciousness,  in  which  every  one  is  the 
immediate  resultant  of  that  which  preceded  it,  whether  that  were  ideational  or  sensational. 
Thus  the  current  of  thought  is  alike  '  spontaneous,'  when  it  flows  onwards  in  one  con- 
tinuous channel  (being  directed  by  a  single  dominant  idea  which  absorbs  the  whole  atten- 
tion), and  when  the  mind  is  freely  accessible  to  external  impressions  and  may  be  entirely 
guided  by  them.  The  phenomena  of  Reverie,  Abstraction,  and  Somnambulism  (as  will  be 
presently  seen)  afford  illustrations  of  both  these  states  ;  which,  though  apparently  opposite 
in  their  nature,  are  really  characterized  by  the  same  essential  feature,  —  namely,  the 
absence  of  the  directing  power  of  the  Will,  —  and  differ  only  as  to  the  subjective  or  the 
objective  characters  of  the  suggestions  which  determine  the  succession  of  thought. 


DETERMINING    POWER    OF    VOLITION.  601 

the  Will  be  suspended,  the  capability  of  correcting  evon  the  most  illusory  ideas 
by  an  appeal  to  'common-sense'  is  for  the  time  annihilated.  Of  this  we  have  a 
typical  example  in  the  state  of  Dreaming  (§  691).  —  Hence  we  see,  that  if  the 
Human  Mind  should  lose  for  a  time  the  power  of  volitional  self-direction,  it  can- 
not shake-off  the  yoke  of  any  'dominant  idea'  however  tyrannical,  but  must 
execute  its  behests; — it  cannot  bring  any  notion  with  which  it  may  be  possessed, 
to  the  test  of  '  common-sense/  but  must  accept  it  as  a  belief,  if  it  be  impressed 
on  the  consciousness  with  adequate  force;  —  it  cannot  recall  any  fact,  even  the 
most  familiar,  that  is  beyond  its  immediate  grasp;  —  upon  any  idea,  therefore, 
with  which  it  may  be  possessed,  the  whole  force  of  its  attention  is  for  the  time 
concentrated,  so  that  the  most  incongruous  conception  presents  itself  with  all  the 
vividness  of  reality;  —  and  finally,  if  the  automatic  activity  of  the  mind,  when 
freed  from  the  controlling  power  of  the  will,  should  depend  more  upon  external 
than  upon  internal  suggestion,  and  hence  should  take  no  determinate  direction  of 
its  own,  one  idea  may  be  readily  substituted  for  another  by  appropriate  means ; 
and  the  whole  state  of  the  convictions,  the  feelings,  and  the  impulses  to  action, 
may  be  thus  altered  from  time  to  time,  without  the  least  perception  of  the  strange- 
ness of  the  transition. 

671.  The  importance  of  this  directing  power  of  the  Will  may  be  best  appre- 
ciated, by  the  examination  of  those  curious  states  in  which  it  is  entirely  sus- 
pended, whilst  the  Intellect  remains  in  full  activity,  and  the  Sensorium  is  freely 
open  to  external  impressions.  Such  conditions  (which  show  us  what  we  should 
be,  if  we  really  were  —  what  some  writers  assure  us  that  we  actually  are  — mere 
thinking  automata,  puppets  moved  in  any  direction  by  the  pulling  of  suggesting- 
strings,  §  580  note)  present  themselves  spontaneously  in  some  individuals,  and 
may  be  induced  in  others;  and  it  is  not  a  little  remarkable  that  they  may  occur 
as  modifications  both  of  the  waking  and  of  the  sleeping  states.  Of  the  former 
we  have  an  example  in  ordinary  Reverie,  a  state  to  which  some  persons  are  pecu- 
liarly prone;  the  characteristic  of  which  is,  that  whilst,  as  in  Dreaming,  the  suc- 
cession of  thought  is  entirely  automatic,  it  is  in  no  small  degree  influenced  by 
external  impressions,  especially  such  as  arise  from  the  various  phenomena  of 
Nature.  It  is  in  minds  in  which  the  emotional  and  imaginative  elements  pre- 
dominate, that  we  usually  find  the  greatest  tendency  to  reverie;  and  the  sequence 
of  thought,  if  subsequently  analysed,  will  be  found  to  have  been  chiefly  deter- 
mined by  these  tendencies.  Now  this  sequence  may  conduct  us  to  notions  alto- 
gether inconsistent  with  our  most  familiar  experience ;  and  yet  we  accept  them  as 
realities,  notwithstanding  this  incongruity,  because  the  ideas  to  which  they  are 
opposed  are  not  present  to  our  minds  at  the  time,  and  the  dormant  state  of  our 
Will  prevents  us  from  making  the  slightest  effort  to  bring  them  before  the  con- 
sciousness. The  state  of  Abstraction,  or  'absence  of  mind/  is  essentially  the 
same  with  that  of  reverie ;  the  chief  difference  being,  that  in  true  Abstraction 
the  mind  is  at  work  ratiocinatively,  a  certain  train  of  thought  being  followed-out 
by  the  intellectual  operations  to  its  logical  conclusion ;  so  that  it  is  the  Philoso- 
pher who  is  most  prone  to  abstraction,  as  the  Poet  is  to  reverie.  Now  it  is  one 
of  the  most  curious  phenomena  of  this  state,  that  external  impressions,  if  re- 
ceived by  the  consciousness  at  all,  are  very  often  wrongly  perceived,  being  inter- 
preted in  accordance  with  the  ideas  which  happen  to  be  dominant  in  the  mind  at 
the  time,  instead  of  giving-rise  to  those  new  ideas  which  ordinarily  connect  them- 
selves with  them,  in  virtue  of  the  individual's  habitual  experience.  The  records1 
of  '  absence  of  mind '  are  full  of  amusing  incidents  of  such  mis-interpretation. 
Nothing  seems  too  strange  for  the  individual  to  believe,  nothing  too  absurd  for 
him  to  do  under  the  influence  of  that  belief.  Thus  of  Dr.  Robert  Hamilton,  a 
well-known  Professor  at  Aberdeen,  who  was  the  author  of  many  productions  dis- 
tinguished for  their  profound  and  accurate  science,  their  beautiful  arrangement, 
and  their  clear  expression,  we  are  informed  that,  "  In  public,  the  man  was  a 
shadow;  pulled-off  his  hat  to  his  own  wife  in  the  streets,  and  apologized  for  not 


602  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

having  the  pleasure  of  her  acquaintance;  went  to  his  classes  in  the  college  on 
the  dark  mornings  with  one  of  her  white  stockings  on  the  one  leg,  and  one  of  his 
own  black  ones  on  the  other;  often  spent  the  whole  time  of  the  meeting  in  moving 
from  the  table  the  hats  of  the  students,  which  they  as  constantly  returned ; 
sometimes  invited  them  to  call  on  him,  and  then  fined  them  for  coming  to  insult 
him.  He  would  run  against  a  cow  in  the  road,  turn  round,  beg  her  pardon, 
call  her  '  Madam/  and  hope  she  was  not  hurt.  At  other  times  he  would  run 
against  posts,  and  chide  them  for  not  getting  out  of  his  way."  ' 

672.  A  state  may  be  artificially  induced  in  many  individuals,  by  a  continued 
fixed  gaze  at  an  object  at  a  moderate  distance,  which  corresponds  with  that  of 
Reverie  and  Abstraction  in  regard  to  the  complete  suspension  of  the  directing 
power  of  the  Will  over  the  current  of  thought,  but  which  differs  from  these  in 
the  readiness  with  which  the  mind  may  be  possessed  with  ideas  suggested  to  it 
through  the  medium  of  language.  This  state  has  been  commonly  known  by  the 
name  Electro- Biological,  from  the  mode  in  which  its  induction  was  originally 
practised  ;2  but  it  is  now  more  frequently  designated  by  the  very  inappropriate 
term  Biological.  The  subject  of  it  may  be  truly  characterized  as  a  thinking 
automaton,  the  whole  course  of  whose  ideas  may  be  determined  by  suggestions 
operating  from  without;  and  his  mind,  having  in  itself  no  power  of  altering  the 
course  of  these  in  even  the  slightest  degree,  is  cut-off  from  all  recourse  to  pre- 
vious experience  for  the  examination  of  their  correctness  or  the  determination 
of  their  fallacy.  The  senses  of  the  biologized  subject  are  freely  accessible  to 
external  impressions;  but,  as  in  the  case  of  the  'absent'  man,  his  perception  of 
these  is  governed  by  the  ideas  which  may  be  dominant  in  his  mind  at  the  time ; 
and  he  may  be  consequently  led  to  any  kind  of  absurd  misinterpretation  of  them. 
Yet  his  state  of  mind  is  not  so  far  removed  from  his  ordinary  condition,  as  to  pre- 
vent his  usual  habits  of  thought  and  feeling  from  displaying  themselves ;  and  he 
has  in  most  cases  a  perfect  recollection  of  what  has  taken  place,  when  he  returns 
to  his  usual  condition  of  mental  activity,  though  sometimes  the  recollection  does 
not  extend  to  particulars.  All  the  phenomena  of  the  '  biologized'  state,  when 
attentively  examined,  will  be  found  to  consist  in  the  occupation  of  the  mind  by 
the  ideas  which  have  been  suggested  to  it,  and  in  the  influence  which  these  ideas 
exert  upon  the  actions  of  the  body.  Thus  the  operator  asserts  that  the  '  subject' 
cannot  rise  from  his  chair,  or  open  his  eyes,  or  continue  to  hold  a  stick  ;  and  the 
1  subject'  thereby  becomes  so  completely  possessed  with  the  fixed  belief  of  the 
impossibility  of  the  act,  that  he  is  incapacitated  from  executing  it,  not  because 
his  will  is  controlled  by  that  of  another,  but  because  his  will  is  in  abeyance,  and 
his  muscles  are  entirely  under  the  guidance  of  the  conviction  which  for  the  time 

1  See  "New  Monthly  Magazine,"  vol.  xxviii.  p.  510. — The  Author  has  heard  from  an 
old  pupil  of  Dr.  Hamilton  an  anecdote  so  singularly  illustrative  of  this  peculiar  condition, 
that  he  cannot  refrain  from  here  introducing  it.  The  Professor,  walking  one  day  along 
the  High  Street  with  the  front  of  his  breeches  open  (no  very  unusual  occurrence  with 
him),  chanced  to  encounter  a  woman  in  a  white  apron ;  and  apparently  mistaking  this 
apron  for  his  own  shirt,  he  laid  hold  of  it,  and  began  to  push  it  into  the  situation  which 
his  shirt  should  occupy ! 

a  The  "Electro-Biologists,"  as  they  termed  themselves,  at  first  maintained  that  a  won- 
derful virtue  resided  in  the  little  disk  of  copper  with  a  zinc  centre,  to  which  they  directed 
the  gaze  of  their  '  subjects.'  It  is  now  universally  admitted,  however,  that  any  object  which 
serves  as  a  point  d'appui  for  the  fixed  gaze,  is  equally  efficacious. — The  Author  has  no 
hesitation  in  avowing  his  belief  in  the  reality  of  the  phenomena,  which  are  described  as 
occurring  in  this  state;  these  having  been  presented  to  himself  and  to  other  scientific 
inquirers,  by  numerous  individuals,  on  whose  honesty  and  freedom  from  all  disposition  to 
deceive  themselves  or  others,  implicit  reliance  could  be  placed.  All  public  exhibitions, 
the  performers  in  which  are  of  questionable  character,  are  of  course  open  to  the  obvious 
fallacy  of  intentional  deceit.  With  regard  to  the  interpretation  of  these  phenomena,  how- 
ever, he  entirely  dissents  from  the  statements  commonly  made,  to  the  effect  that  the  Will 
of  the  'biologized'  subject  is  entirely  under  the  control  of  that  of  the  operator;  since  he 
regards  the  latter  as  having  no  other  influence  over  the  former,  than  through  the  «r/y- 
which  his  language  and  manner  convey. 


DETERMINING    POWER    OF    VOLITION.  603 

possesses  his  mind.  So  again,  when  he  is  made  to  drink  a  glass  of  water,  and  is 
assured  that  it  is  coffee,  or  wine,  or  milk,  that  assurance,  delivered  in  a  decided 
tone,  makes  a  stronger  impression  on  his  mind  than  that  which  he  receives  through 
his  taste,  smell,  or  sight;  and  not  being  able  to  judge  and  compare,  he  yields  him- 
self up  to  the  'dominant  idea.' '  Here,  again,  we  perceive  that  it  is  not  really 
the  will  of  the  operator  which  controls  the  sensations  of  the  subject ;  but  the  sug- 
gestion of  the  operator  which  excites  a  corresponding  idea,  the  falsity  of  which 
is  not  corrected,  simply  because  the  mind  of  the  subject,  being  completely 
engrossed  by  it,  cannot  apprehend  the  truth  less  forcibly  impressed  on  it 
through  his  own  senses. — The  same  general  statement  applies  to  what  has 
been  designated  as  'control  over  the  memory/  The  subject  is  assured  that 
he  cannot  remember  the  most  familiar  thing,  his  own  name  for  example ;  and  he 
is  prevented  from  doing  so,  not  by  the  will  of  the  operator,  but  by  that  con- 
viction of  the  impossibility  of  the  mental  act  which  engrosses  his  own  mind,  and 
by  the  want  of  that  voluntary  control  over  the  direction  of  his  thoughts,  which 
alone  can  enable  him  to  recall  the  desiderated  impression.  And  the  abolition 
of  the  sense  of  personal  identity  (Mr.  A.  believing  himself  to  be  Mrs.  B.,  or 
Mrs.  C.  believing  herself  to  be  Mr.  D.,  and  acting  in  conformity  with  that  belief) 
is  induced  in  the  same  mode;  the  assurance  being  continually  repeated,  until  it 
has  taken  full  possession  of  the  mind  of  the  'subject/  who  cannot  so  direct  his 
thoughts  as  to  bring  his  familiar  experience  to  antagonize  and  dispel  the  illusive 
idea  thus  forced  upon  him.  The  phenomena  presented  by  different  '  biologized 
subjects'  are  by  no  means  the  same ;  for  in  some  individuals  it  is  the  relation  of 
the  mind  to  bodily  action  which  is  most  remarkably  affected,  in  others  it  is  the 
relation  of  the  perceptive  consciousness  to  sensations,  and  in  others  (especially 
those  who  are  naturally  of  an  imaginative  and  excitable  disposition)  it  is  the 
course  of  thought  and  of  emotion  which  is  most  completely  under  external  guid- 
ance. It  is  frequently  to  be  observed,  moreover,  that  some  capability  of  voli- 
tional effort  still  remains,  so  that  the  '  subject'  endeavours  to  resist  the  commands 
of  the  operator ;  but  this  may  usually  be  subdued  by  the  emphatic  reiteration  of 
the  assurance,  "You  must  do  this,"  or  "You  cannot  do  that,"  which,  when  it 
takes  complete  possession  of  the  mind  of  the  subject,  reduces  the  will  to  a  state 
of  entire  powerlessness.2 

673.  It  is  obvious  that  if  the  account  here  given  of  the  condition  of  the  Mind, 
and  of  the  mode  of  its  operation  on  the  Body,  in  the  states  of  natural  and  arti- 
ficial Reverie  and  Abstraction,  be  correct,  all  the  actions  performed  in  these 
states  must  be  regarded  as  essentially  automatic  in  their  nature  ;  the  course  of 
thought  being  entirely  determined  by  the  play  of  Suggestions  upon  the  associa- 

1  It  is  very  curious  to  observe,  in  some  instances,  the  perplexity  arising  from  the  con- 
trariety between  the  opposing  sensory  impressions.  The  mind  seems  unable  to  reconcile 
this  contrariety,  and  yields  itself  up  to  the  impression  which  is  most  strongly  felt.  Some- 
times it  is  convinced  by  the  repeated  assurances  of  the  operator,  so  long  as  the  taste  alone 
is  opposed  to  them,  but  attaches  a  superior  importance  to  the  indications  of  sight;  in 
other  individuals,  again,  the  indications  of  sight  may  be  put  aside,  and  yet  the  '  subject' 
cannot  be  made  to  believe  what  is  in  opposition  to  his  sense  of  taste.  There  are  some 
individuals  who  can  never  be  thus  played-upon,  notwithstanding  that  their  muscular 
movements  and  their  purely  mental  conceptions  are  completely  amenable  to  this  kind  of 
direction. 

a  It  is  worthy  of  particular  notice  in  this  connection,  that  this  want,  not  really  of  power 
to  move,  but  of  belief  in  the  possession  of  the  power,  is  a  frequent  characteristic  of  that 
state  of  the  nervous  system  which  is  commonly  designated  as  'Hysterical;'  and  that 
here,  also,  the  most  efficacious  treatment  consists  in  the  encouragement  of  volitional  efforts 
on  the  part  of  the  patient  to  put  the  paralysed  limbs  in  action,  and  in  the  repetition  of 
assurances  that  she  will  recover  the  use  of  them,  if  she  only  take  the  appropriate  means. 
The  expectation  of  recovery  excited  in  other  ways,  produces  the  same  effect ;  and  thus 
it  has  been,  that  many  pseudo-miracles  have  been  wrought  on  this  class  of  patients  by 
Religious  enthusiasts,  and  that  many  wonderful  cures  have  been  effected  by  the  supposed 
influence  of  Mesmerism.  All  that  is  wanted,  is  that  state  of  confident  anticipation,  which 
is  commonly  designated  as  Faith.  (See  g  837.) 


604  FUNCTIONS   OF   THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

tions  previously  formed,  arid  all  the  bodily  movements  being  the  direct  manifes- 
tations of  the  ideas  which  possess  the  mind  at  the  time,  just  as  the  ordinary 
movements  of  '  expression  '  are  of  its  emotions.  And  it  is,  therefore,  in  these 
remarkable  phases  of  psychical  existence,  that  we  have  the  clearest  manifestation 
of  the  power  which  Cerebral  changes  possess,  to  produce  muscular  movement 
independently  either  of  Volition  or  of  Emotion ;  an  action  which  may  be  distin- 
guished as  ideo-motor,  since  it  only  takes-place  when  these  changes  are  of  a  kind 
to  awaken  the  ideational  consciousness;  and  which  is  a  true  ' reflex '  action  of 
the  Cerebrum. 

674.  Returning  now  from  the  consideration  of  these  Pathological  conditions 
of  Mind  (as  they  may  be  not  unfairly  designated)  to  the  examination  of  the  Psy- 
chical constitution  of  Man  in  the  state  of  normal  activity  of  his  faculties,  we  shall 
find  that  very  important  data  may  be  drawn  from  these  sources,  with  regard  to 
the  modus  operandi  of  the  Will,  and  the  manner  in  which  our  conduct  is  deter- 
mined. For  we  have  seen  that,  in  so  far  as  the  directing  influence  of  the  Will 
over  the  current  of  thought  is  suspended,  the  individual  becomes  a  thinking  auto- 
maton, destitute  of  the  power  to  withdraw  his  attention  from  any  idea  or  feeling 
by  which  his  mind  may  be  possessed,  and  as  irresistibly  impelled,  therefore,  to 
act  in  accordance  with  this,  as  the  low.er  animals  are  to  act  in  obedience  to  their 
instincts.  In  so  far,  therefore,  as  this  directing  influence  is  not  exercised,  the 
succession  of  trains  of  thought  which  occupy  the  consciousness  (associated,  or  not, 
with  feelings  that  give  them  an  emotive  character)  must  be  considered  as  depen- 
dent on  the  '  reflex  action '  of  the  Cerebrum ;  the  nature  of  this  action  being 
determined,  not  merely  by  the  original  constitution  of  the  organ,  but  by  the  mode 
in  which  it  has  been  subsequently  exercised ;  its  nutrition  taking  place  in  such 
conformity  to  the  impressions  made  upon  it,  and  to  the  modes  in  which  it  is 
habitually  directed  by  the  Will,  that  it  grows-to  these,  so  that  a  new  organization 
thus  comes  to  be  established,  by  which  habits  of  thought  are  determined,  such  as 
would  not  have  arisen  from  its  original  constitution.1  The  variety  of  phases 
which  these  different  states  present,  is  chiefly  dependent  upon  the  following  ele- 
ments ;— (1)  the  relative  degree  in  which  the  Mind  is  in  a  state  of  receptivity 
for  external  impressions,  or  is  attending  only  to  what  passes  within  itself;  (2) 
the  degree  in  which  the  coherence  of  the  successive  states  is  maintained  by  the 
continuance  and  right  operation  of  the  preformed  associations,  so  that  trains  of 
thought  are  consistently  carried-out,  and  reasoning  processes  correctly  performed ; 
and  (3)  the  degree  in  which  the  normal  operation  of  the  intellectual  faculties  is 
disturbed  by  emotional  excitement,  either  general,  or  limited  to  one  class  of 
feelings.  The  influence  of  the  first  of  these  elements  is  remarkably  seen  in 
the  contrast  between  natural  and  artificial  Reverie  (§  671,  672);  also  between 
some  forms  of  natural  and  artificial  Somnambulism  (§  693-695);  and  not  less 
between  different  forms  of  insanity,  since  in  this  last  condition  we  find  some 
patients  constantly  brooding  over  particular  trains  of  thought,  and  almost  inca- 
pable of  being  turned  from  the  contemplation  of  these  by  external  suggestions, 
whilst  others  are  no  less  remarkable  for  the  instability  of  their  mental  states,  and 
for  the  readiness  with  which  a  new  direction  may  be  given  to  the  thoughts  by 
sensory  impressions.  The  influence  of  the  second  element  is  strikingly  mani- 
fested in  the  difference  between  the  various  phases  of  the  state  of  Dreaming,  and 
in  the  contrast  between  the  incoherence  of  the  commoner  forms  of  this  (§  691), 
and  that  consistency  in  the  trains  of  thought  which  generally  characterizes  the 
state  of  Somnambulism ;  but  it  is  yet  more  remarkably  displayed  in  those  forms 
of  Delirium  and  Insanity  (§  706),  which  are  especially  characterized  by  the  com- 
plete confusion  of  the  Intellectual  powers,  all  previous  states  of  consciousness 

1  See  Dr.  Laycock's  Essay  <  On  the  Reflex  Function  of  the  Brain,'  in  the  "  Brit,  and  For. 
Med.  Review,"  vol.  xix.  p.  298. — The  Author  would  beg  to  refer-back  to  the  antecedent 
portions  of  this  inquiry,  and  especially  to  \^  587,  588,  as  showing  to  what  extent  he 
regards  the  organization  of  the  Cerebrum  as  determining  its  mode  of  psychical  activity. 


DETERMINING    POWER    OF    VOLITION.  605 

being  (as  it  were)  jumbled-together,  and  the  order  of  their  recurrence  and  the 
nature  of  the  new  combinations  which  may  arise  out  of  them,  being  irreducible 
to  any  principle  of  orderly  sequence.  The  influence  of  the  third  element  is  well 
seen  in  those  forms  of  artificial  Reverie  and  Somnambulism,  in  which  the  feelings 
as  well  as  the  ideas  admit  of  being  played-upon  by  external  influences ;  for  it  is 
easy  to  bring  the  mind  of  the  'subject'  under  the  domination  of  any  particular 
emotion,  by  taking  the  appropriate  means  to  excite  it;  '  and,  so  long  as  this  may 
continue,  the  language  and  actions  most  obviously  display  its  impress.  But  it  is 
in  Insanity  (Sect.  8),  that  we  best  see  the  influence  of  Emotional  states  upon  the 
course  of  thought  and  of  action ;  for  here  we  find  them  supplying  impulses  to 
bodily  action,  which  the  weakened  Will  cannot  resist,  although  the  intellect  dis- 
tinctly apprehends  the  evil  consequences  of  such  actions ;  or,  on  the  other  hand, 
we  find  them  directing  the  whole  course  of  mental  activity,  giving  a  wrong  colour 
to  all  the  ideas  which  are  related  to  them,  and  so  attracting  the  attention  to  the 
trains  of  thought  founded  upon  these,  that  they  come  to  attain  a  complete  domi- 
nation over  the  mind,  and  hence  over  the  conduct,  to  which  they  supply  motives 
of  such  potency  that  the  Will  can  neither  resist  them,  nor  withdraw  the  mind 
from  attending  to  them. 

675.  Thus,  then,  we  see  that  in  all  those  states  in  which  the  directing  power  of  the 
Will  over  the  current  of  thought  is  suspended,  the  course  of  action  is  determined 
by  some  dominant  idea,  which  for  the  time  has  full  possession  of  the  mind,  and 
from  which  the  individual  has  no  power  of  withdrawing  his  consciousness ;  the 
motive  power  of  this  idea,  being  such  as  either  impels  to  action  by  a  feeling  of 
internal  necessity  (analogous  to  that  which  prompts  the  reflex  actions  of  the 
Cranio-Spinal  axis),  or  solicits  it  by  the  anticipation  of  pleasure  in  its  result  or 
of  pain  in  abstinence  from  it.  On  the  other  hand,  the  man  in  full  possession 
of  his  Volitional  faculty,  whilst  equally  amenable  with  those  in  the  foregoing 
ftates  to  the  influence  of  the  motive  power  of  ideas,  differs  from  them  all  in  this 
most  important  particular, — that  he  has  the  power  of  refraining  from  action  under 
the  immediate  pressure  of  motives,  and  of  so  far  modifying  their  relative  force 
by  the  mode  in  which  he  contemplates  them,  that  their  original  balance  may  be 
'.•ompletely  altered,  and  hence  his  ultimate  determination,  whilst  still  governed  by 
the  predominance  of  motives,  may  be  entirely  different  from  that  on  which  he 
would  have  acted,  if  he  had  given  way  to  his  first  impulse.  For  just  as  we  may 
direct  our  Intellectual  operations  by  an  exercise  of  Volition,  so  as  to  fix  upon  cer- 
tain ideas  only,  out  of  the  many  which  present  themselves  to  our  consciousness, 
and  to  limit  our  attention  to  certain  peculiar  aspects  of  these  (§  640),  so  may  we 
fix  our  attention  upon  any  one  or  more  among  the  motives  which  tend  to  deier* 
mine  our  action,  and  keep  these  (as  it  were)  in  a  strong  light  before  the  mind's 
eye,  whilst  by  withdrawing  our  attention  from  others,  we  virtually  throw  them 
into  the  back-ground,  as  we  can  do  with  regard  to  objects  of  Sensation  (§  592). 
And  further,  by  calling  the  Reasoning  powers  into  operation,  and  bringing  them 
to  bear  upon  the  question  at  issue,  so  as  to  follow-out  each  of  the  modes  of  action 
that  are  before  the  mind  to  its  probable  consequences,  the  Will  indirectly  brings 
a  set  of  new  motives,  arising  out  of  these  consequences,  before  the  judgment ; 
and  these,  at  first  overlooked,  may  become  important  elements  in  the  decision. 
On  the  other  hand,  it  may  be  that  in  thus  reasoning-out  the  probable  conse- 
quences of  an  action,  motives  which  at  first  presented  themselves  in  great  strength, 
lose  more  or  less  of  their  force,  and  even  become  altogether  futile. — It  is  in  these 
modes  that  <  second  thoughts '  generally  prove  to  be  the  best,  save  where  selfish 
considerations  are  brought  to  take  the  place  of  primary  generous  impulses ;  whilst 

1  Thus  in  the  'biologized'  state  (g  672),  it  is  often  sufficient  to  ask  the  <  subject '- 
"  Why  are  you  so  angry,"  "  Why  are  you  so  sad,"  &c., — to  induce  these  conditions  respec- 
tively, the  suggestions  being  here  conveyed  verbally ;  whilst  in  the  '  hypnotic  '  state  here- 
after to  be  described,  there  is  a  very  curious  susceptibility  to  the  influence  of  musculai 
associations  on  emotional  states  ($  694). 


606  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

a  hasty  determination  often  leads  to  wrong  action,  because  ail  the  motives  that 
should  be  taken  into  account  have  not  been  duly  weighed.1 

676.  Now  if  we  examine  into  the  different  kinds  of  Motive  Powers,  which, 
under  the  permission 'or  the  intentional  direction  of  the  Will,  are  the  sources  of 
Human  action,  we  shall  find  that  they  maybe  ranged  under  the  following  heads : 
— (1)  Previously-acquired  Habits,  which  automatically  incite  us  to  do  as  we  have 
been  before  accustomed  to  do  under  the  like  circumstances,  without  the  idea  of 
prospective  pleasure  or  pain,  or  of  right  or  wrong,  being  at  all  present  to  our 
minds.  The  formation  of  Habits,  both  of  thought  and  action,  seeins  referable  to 
the  psychical  principle  of  Contiguous  Association  (§  632)  and  to  the  physiological 
principle  of  Nutritive  Assimilation  (§  346),  which,  in  regard  to  the  operations'of 
the  Cerebrum,  seem  to  be  only  different  expressions  of  the  same  fact;  namely, 
that  whatever  mode  of 'activity  has  been  once  strongly  impressed  on  the  organ, 
this  has  a  tendency  to  perpetuate  itself.  In  so  far  as  the  Will  yields  to  this  ten- 
dency, instead  of  controlling  it,  the  individual  becomes  the  slave  of  routine,  and 
this  condition  is  often  very  remarkably  presented  by  persons  who  are  deficient  in 
Volitional  power  (as  it  is  also  among  the  lower  animals),  from  whose  actions  we 
may  derive  our  best  illustrations  of  what  Habit  will  do,  when  it  is  not  under  the 
direction  of  any  higher  principle.2  The  tendency  to  habitual  action  is  so  univer- 

1  It  has  been  held  by  some,  that  when  a  man  is  struggling  with  a  temptation,  and  the 
motives  to  good  and  the  motives  to  evil  are  nearly  in  equilibrium,  like  weights  in  the  two 
scales  of  the  balance,  the  Will  acts  as  an  independent  preponderating  power,  like  a  hand 
pushing-down  the  scale-beam  on  one  side.  It  appears  to  the  Author,  however,  to  be  much 
more  conformable  to  the  results  of  a  careful  examination  of  our  own  conduct,  to  regard 
the  Will  as  imparting  an  augmented  gravity  (as  it  were)  to  the  weights  on  one  side,  by 
directing  attention  to  their  value,  and  by  indirectly  making  additions  to  them,  in  the 
manner  stated  above ;  whilst  it  diminishes  the  force  of  those  on  the  other  side,  by  pre- 
venting the  mind  from  giving  its  attention  to  them,  and  also  (it  may  be)  by  virtually  ab- 
stracting some  of  them  from  the  scale. 

a  It  is  not  uncommon  to  meet  with  Idiots,  in  whom  the  tendency  to  the  automatic  recur- 
rence of  moles  of  action  once  impressed  on  the  consciousness,  is  extremely  remarkable. 
The  following  is  stated  by  Miss  Marti neau,  in  regard  to  a  youth  under  her  own  observa- 
tion, who,  in  consequence  of  early  injury  to  the  brain,  never  acquired  the  power  of  speech, 
or  of  understanding  the  language  of  others,  or  of  in  any  way  recognizing  other  minds ;  but 
was  at  the  same  time  strongly  affected  by  sensory  impressions.  "  He  could  endure  nothing 
out  of  its  position  in  space  or  its  order  in  time.  If  any  new  thing  was  done  to  him  at  any 
minute  of  the  day,  the  same  thing  must  be  done  at  the  same  minute  every  day  thenceforward." 
Thus,  although  he  disliked  personal  interference,  his  hair  and  nails  having  been  one  day 
cut  at  ten  minutes  past  eleven,  the  next  day,  and  every  day  after,  at  ten  minutes  past 
eleven,  he  "as  if  by  a  fate,"  brought  comb,  scissors  and  towel;  and  it  was  necessary  to 
cut  a  snip  of  hair  before  he  would  release  himself.  Yet  he  had  no  knowledge  whatever  of 
the  measurement  of  time  by  clocks  and  watches,  and  was  no  less  minutely  punctual  in  his 
observances  when  placed  beyond  the  reach  of  these  aids.  So  in  regard  to  form,  number, 
and  quantity,  his  actions  were  equally  methodical.  He  occupied  himself  much  in  making 
paper-cuttings,  which  were  remarkable  for  their  symmetry.  If,  when  he  was  out  of  the 
room,  a  brick  were  taken  from  the  heap  with  which  he  amused  himself,  he  would  pass  his 
hand  over  them,  spread  them  a  little,  and  then  lament  and  wander  about  till  the  missing 
one  was  restored.  If  seven  comfits  had  once  been  put  into  his  hand,  he  would  not  rest 
with  six;  and  if  nine  were  given,  he  would  not  touch  any  until  he  had  returned  two. 
("Letters  on  the  Laws  of  Man's  Nature  and  Development,"  p.  71.  See  also  "Household 
Words,"  vol.  ix.  p.  198.) — It  would  be  easy  to  adduce  multitudes  of  analogous  instances 
from  the  actions  of  animals,  especially  such  as  are  purposely  trained-to  particular  habits, 
by  taking  advantage  of  the  principle  of  'contiguous  association,'  which  seems  to  be  pecu- 
liarly strong  in  Dogs,  Horses,  &c.  And  the  recurrence  of  particular  actions  at  particular 
intervals  of  time,  without  any  means  of  consciously  estimating  its  passage,  or  any  incidents 
that  can  suggest  the  return  of  the  period,  is  a  very  curious  indication  of  the  degree  in  which 
organic  changes  in  the  Nervous  System,  once  determined  by  a  certain  number  of  repeti- 
tions, tend  to  perpetuate  themselves.  Thus  a  dog  that  has  been  accustomed  to  receive 
food  at  a  certain  hour  and  place  every  day,  will  come  in  search  of  it  with  extraordinary 
punctuality ;  and  the  horse  of  a  commercial  traveller,  after  going  the  same  journey  a  few 
times,  will  stop  at  the  houses  of  all  his  master's  customers ;  and  when  he  has  been  pulled- 
up  at  a  new  point  on  one  journey,  will  spontaneously  stop  at  the  same  point  on  the  next, 
--a  fact  of  which  the  Author  has  personal  knowledge. 


DETERMINING    POWER    OF    VOLITION.  607 

sally  recognized  as  an  important  part  of  our  psychical  nature,  that  Man  has  been 
said  to  be  '  a  bundle  of  habits/  Where  the  habits  have  been  judiciously  formed 
in  the  first  instance,  the  tendency  is  an  extremely  useful  one,  prompting  us  to  do 
that  spontaneously,  which  might  otherwise  require  a  powerful  effort  of  the  Will;1 
but,  on  the  other  hand,  if  a  bad  set  of  habits  have  grown-up  with  the  growth  of 
the  individual,  or  if  a  single  bad  tendency  be  allowed  to  become  an  habitual  spring 
of  action,  a  far  stronger  effort  of  Volition  will  be  required  to  determine  the  con- 
duct in  opposition  to  them.  This  is  especially  the  case,  when  the  habitual  idea 
possesses  an  Emotional  character,  and  becomes  the  source  of  desires;  for  the  more 
frequently  these  are  yielded-to,  the  more  powerful  is  the  solicitation  they  exert. 
— (2).  Emotional  States,  which  incite  us  to  particular  actions,  by  the  expectation 
of  gratification  either  in  the  act  itself  or  in  some  consequence  which  our  reason 
leads  us  to  anticipate  from  it,  or  by  the  expectation  of  pain  if  the  act  be  not  per- 
formed. All  those  desires  and  aversions  which  have  so  large  a  share  in  deter- 
mining  our  conduct,  come  under  this  category ;  and  to  it  must  likewise  be  referred 
all  those  considerations  which  are  simply  prudential,  these  usually  having  refer- 
ence to  the  remoter  effects  which  our  actions  are  likely  to  have  upon  our  own  wel- 
fare or  upon  that  of  others,  and  thus  bringing  before  the  mind,  as  elements  in  its 
determination,  certain  additional  objects  of  desire  or  aversion. — (3).  Notions  of 
Right  and  of  Duty,  which,  so  far  as  they  attach  themselves  to  our  actions,  give 
them  a  moral  and  religious  character.  These  may  act  simply  as  ideas,  whose 
coercive  power  depends  upon  the  intensity  with  which  they  are  brought  before 
the  mind ;  but  they  obtain  a  much  stronger  influence,  when  they  acquire  an  Emo- 
tional character  from  the  association  of  the  feeling  of  desire  with  the  idea  of  obli- 
gation j  that  is,  when  we  feel  a  wish  to  do  that  which  we  are  conscious  we  ought 
to  do.  This  association  is  one,  which  it  is  peculiarly  within  the  capability  of  the 
Will  to  cherish  and  strengthen.  And  still  more  powerful  is  the  operation  of  these 
combined  motives,  when  a  constant  habit  of  acting  upon  them  has  been  formed ; 
for  the  strongest  desires  are  then  immediately  repressed,  the  strongest  aversions 
cease  to  exert  an  influence,  when  once  the  question  is  looked-at  in  its  Moral 
aspect,  and  a  clear  perception  has  been  attained  of  its  right  and  its  wrong  side.2 

1  This  is  especially  the  case  with  regard  to  habits  of  Intellectual  exertion,  which  are  in 
themselves  peculiarly  free  from  any  emotional  complication.  The  Author  can  speak  from 
long  and  varied  experience,  of  the  immense  saving  of  exertion  which  arises  from  the  for- 
mation of  methodical  habits  of  mental  labour ;  which  cause  the  ordinary  routine  to  be  per- 
formed with  a  far  less  amount  of  fatigue,  than  would  be  required  on  a  more  desultory 
system  (g  647).  Even  here,  however,  care  should  be  taken  to  avoid  allowing  one's-self  to 
be  so  much  the  slave  of  habits,  that  all  mental  labour,  save  that  which  is  undertaken  at  a 
particular  time,  or  in  a  particular  place,  becomes  difficult  and  wearisome. 

a  The  difference  between  the  habitual,  the  prudential,  and  the  moral  aspects  of  the  verv 
same  action,  may  be  made  apparent  by  a  very  simple  illustration. — We  will  suppose  that  a 
man  has  been  accustomed  to  take  a  ride  every  day  at  a  particular  hour ;  his  whole  naturo 
so  accommodates  itself  to  the  habit,  that  he  feels  both  mentally  and  physically  uncomfort- 
able at  any  interruption  to  the  usual  rhythm.  But  suppose  that,  just  as  the  appointed 
hour  comes  round,  the  sky  becomes  overcast,  threatening  the  rider  with  a  drenching  if  he 
perseveres  in  his  intention;  his  decision  will  then  be  founded  on  &  prudential  consideration 
of  the  relative  probabilities  of  his  escaping  or  of  his  being  exposed  to  the  shower,  and  of 
how  far  the  enjoyment  he  may  derive  from  his  ride  is  likely  to  be  replaced  by  the  discom- 
fort of  a  thorough  wetting.  But  suppose,  further,  that  instead  of  taking  a  mere  pleasure- 
ride,  a  Medical  man  is  about  to  set-forth  on  a  professional  visit  to  a  patient  whose  condi 
tion  requires  his  aid;  a  new  motive  is  thus  introduced,  which  alters  the  condition  of  the 
whole  question,  making  it  no  longer  one  of  prudence  only,  but  one  of  morality.  Another 
motive  which  should  give  the  question  a  moral  aspect,  would  be  consideration  for  himself, 
and  the  risk  of  life  or  health  he  might  run ;  this  should  be  decisive,  where  the  motive 
which  impels  him  to  the  act  in  question  is  merely  that  of  self-gratification ;  but  if  it  bring 
into  antagonism  his  duty  to  his  patient  and  his  desire  to  benefit  him,  and  on  the  other 
hand  his  duty  to  himself  and  his  regard  for  the  ulterior  welfare  of  those  who  may  be 
immediately  dependent  upon  him,  the  question  has  its  right  and  its  wrong  aspect  on  both 
sides  ($  617),  and  the  right  may  only  be  determined  after  a  careful  balance  of  probabili- 
ties. Such  moral  conflicts  are  continually  occurring  amongst  Medical  Practitioners,  in 


608  FUNCTIONS   OF  THE   CEREBRO-SPINAL  NERVOUS   SYSTEM. 

677.  From  the  time  when  the  Human  being  first  becomes  conscious  that  he 
has  a  Volitional  power  within  himself  of  determining  the  succession  of  his  mental 
states,  from  that  time  does  he  begin  to  be  responsible  for  it ;  and  in  proportion  as 
he  exerts  that  power,  does  he  emancipate  himself  from  the  domination  of  his  con- 
stitutional or  automatic  tendencies,  and  make  himself  a  free  agent.  It  is  a  prin- 
ciple now  recognized  by  all  the  most  enlightened  Educators,  that  the  development 
of  this  power  of  self-control  ought  to  be  the  object  of  all  nursery  discipline ;  and 
the  process  of  its  acquirement  is  very  gradual.  When  an  infant  is  excited  to  a 
fit  of  passion  by  some  unpleasant  sensation,  its  nurse  attempts  to  restore  its  equa- 
nimity by  presenting  some  new  object  to  its  attention,  so  that  the  more  recent  and 
vivid  pleasurable  impression  may  efface  the  sense  of  past  uneasiness.  As  the 
infant  grows  into  childhood,  the  judicious  parent  no  longer  trusts  to  mere  sensory 
impressions  for  the  diversion  of  the  passionate  excitement,  but  calls-up  in  its  mind 
such  ideas  and  feelings  as  it  is  capable  of  appreciating,  and  endeavours  to  keep 
the  attention  fixed  upon  these,  until  the  violence  of  the  emotion  has  subsided ; 
and  recourse  is  had  to  the  same  process,  whenever  it  is  desired  to  check  any  ten- 
dency to  action  which  depends  upon  the  selfish  propensities, — appeal  being  always 
njade  to  the  highest  motives  which  the  child  is  capable  of  recognizing,  and  pun- 
ishment being  only  had  recourse-to,  for  the  purpose  of  supplying  an  additional  set 
of  motives  when  all  others  fail.  For  a  time,  this  process  of  external  suggestion 
may  need  to  be  continually  repeated,  where  there  are  strong  impulses  whose 
unworthy  character  calls  for  repression ;  but  if  it  be  judiciously  adapted  and  con- 
sistently perse vered-in,  a  very  slight  suggestion  serves  to  recall  the  superior  mo- 
tives to  the  conflict.  And  in  further  space,  the  child  comes  to  feel  that  he  has 
himself  the  power  of  recalling  them,  and  of  controlling  his  urgent  impulses  to  im- 
mediate action.  The  power  of  self-control,  thus  usually  acquired  in  the  first 
instance  in  regard  to  those  impulses  which  directly  determine  the  conduct,  gra- 
dually extends  itself  to  the  habitual  succession  of  the  thoughts;  and  in  proportion 
as  this  is  brought  under  the  direction  of  the  Will,  does  the  individual  become 
capable  of  forming  his  own  character,  and  of  guiding  his  actions  according  to  the 
indications  of  his  Moral  Sense. 

678.  It  must  not  be  forgotten,  however,  that  the  power  of  self-control  may  be 
turned  to  a  bad  as  well  as  to  a  good  account;  and  that  the  value  of  its  results  will 
entirely  depend  upon  the  direction  in  which  it  is  employed.  The  thoughts  may 
be  so  determinately  drawn-away  from  the  higher  class  of  motives,  the  suggestions 
of  conscience  so  habitually  disregarded,  and  the  whole  attention  so  completely 
fixed  upon  the  gratification  of  selfish  or  malevolent  propensities,  that  the  Human 
nature  acquires  far  more  of  the  Satanic  than  of  the  Divine  character;  the  high- 
est development  of  this  type  (if  the  term  may  be  permitted)  being  displayed  by 
those,  who  use  their  power  of  self-control  for  the  purposes  of  hypocrisy  and  dis- 
simulation, and  cover  the  most  malignant  designs  under  the  veil  of  friendship. 
Such  men  (whose  portraiture  is  presented  by  our  great  Dramatist  in  the  character 
of  lago)  show  us  to  what  evil  account  the  highest  Intellect  and  the  most  power- 
ful Will  may  be  turned,  when  directed  by  the  baser  class  of  motives ;  and  we 
cannot  but  feel  that  they  are  far  more  degraded  in  the  moral  scale,  than  those 
who,  having  never  learned  to  control  their  animal  propensities,  and  being  uncon- 
scious of  the  very  existence  of  a  higher  nature  within  themselves,  simply  obey 
the  promptings  of  their  automatic  impulses,  and  are  rather  to  be  considered  as 
ill-conditioned  automata,  than  as  vicious  men. — Of  this  latter  class,  some,  from 
original  constitution  and  early  influences  of  the  most  degrading  kind,  seem  alto- 
gether destitute  of  anything  but  a  brutal  nature ;  these  ought  to  be  treated  as  irre- 
sponsible beings,  and,  as  such,  restrained  by  external  coercion  from  doing  injury 

regard  to  exposure  to  the  severity  of  the  weather,  to  dangerous  infection,  or  to  risks  of 
other  kinds;  and  the  decision  will  mainly  depend  upon  the  previously-formed  habit,  on  the 
one  hand  of  disregarding  all  considerations  connected  with  self,  on  the  other  of  attaching 
special  weight  to  them. 


OF    SLEEP    AND    SOMNAMBULISM.  609 

to  society.  But  this  class  is  small  in  proportion  to  that  of  individuals  who  act 
viciously,  simply  because  they  have  never  been  led  to  know  that  any  other  course 
is  open  to  them,  or  to  feel  any  motives  that  might  give  them  a  different  impulse. 
With  these,  the  object  should  rather  be  to  awaken  the  higher  parts  of  the  moral 
nature,  "  to  find  out  the  holy  spot  in  every  child's  heart,"  and  to  develope  habits 
of  self-control  in  the  manner  just  described,  than  to  subjugate  by  external 
restraint;  and  the  success  which  has  attended  this  method,  in  the  hands  of  those 
who  have  judiciously  applied  it,  is  sufficient  evidence  of  its  superiority ;  many  of 
the  most  apparently-debased  natures  having  been  thus  elevated  to  a  grade,  which 
it  seemed  at  first  impossible  they  could  ever  attain. 

679.  From  the  Satanic,  or  positively-and  wilfully-evil  type  of  Human  nature, 
in  which  the  highest  powers  are  turned  to  the  worst  account,  we  are  thus  con- 
ducted through  the  brutal  or  negatively-evil  type,  towards  the  higher  aspect  of 
Humanity,  which  is  presented  by  those  who  habitually  keep  before  them  the 
Divine  ideal,  and  who  steadily  endeavour  to  bring  their  whole  nature  into  con 
formity  with  it.     This  is  not  to  be  effected  by  dwelling  exclusively  on  any  one 
set  of  the  motives  already  referred-to  (§  618),  as  those  which  the  truly  religious 
man  keeps  before  his  mind.     Even  the  idea  of  Duty,  operating  alone,  tends  to 
reduce  the  individual  to*the  subservience  of  a  slave,  rather  than  to  induce  in  him 
that  true  mastery  over  himself,  which  consists  in  such  a  regulation  of  his  emo- 
tions and  propensities,  that  his  course  of  duty  becomes  the  spontaneous  expression 
of  his  own  higher  nature ;  but  it  is  a  most  powerful  aid  in  the  acquirement  of  that 
regulation,  by  the  fixation  of  the  thoughts  and  affections  on  "  things  on  high," 
which  is  the  best  means  of  detaching  them  from  all  that  is  earthly  and  debasing. 
It  is  by  the  assimilation,  rather  than  by  the  subjugation,  of  the  Human  Will 
to  the  Divine,  that  Man  is  really  lifted  towards  God  ;  and  in  proportion  as  this 
assimilation  has  been  effected,  does  it  manifest  itself  in  the  life  and  conduct;  so 
that  even  the  lowliest  actions  become  holy  ministrations  in  a  temple  consecrated 
by  the  felt  presence  of  the  Divinity.     Such  was  the  life  of  the  Saviour;  towards 
that  standard  it  is  for  the  Christian  disciple  to  aspire.1 

7. — Of  Sleep  and  Somnambulism. 

680.  It  is  a  peculiar  feature  in  the  physiology  of  the  Cerebral  and  Sensorial 
Ganglia,  that  their  activity  undergoes  a  periodical  suspension,  more  or  less  com- 
plete ;  the  necessity  for  this  suspension  arising  out  of  the  fact  that  the  exercise 
of  their  functions  is  in  itself  destructive  to  their  substance,  so  that,  if  this  be 
not  replaced  by  nutritive  regeneration,  they  speedily  become  incapacitated  for 
further  use.     In  ordinary  profound  Sleep,  there  is  a  state  of  complete  uncon- 
sciousness, so  far  as  external  phenomena  are  concerned;  no  ordinary  impressions 
upon  the  organs  of  sense  being  either  felt  or  perceived ;  although  an  extraordi- 
nary impression,  or  even  an  habitual  one  upon  which  the  attention  has  been  pre- 
viously fixed,  as  that  at  which  the  slumberer  is  to  awake  himself  (§  687),  occa- 
sions a  renewal  of  sensorial  activity.     It  is  in  this  capability  of  being  aroused  by 
external   impressions,  that   the   chief  difference   lies   between    Sleep   and   the 
abnormal  condition  of  Coma,  whether  this  arise  from  the  influence  of  pressure 
or  effusion  within  the  cranium,  or  be  consequent  upon   the  poisoning  of  the 
blood  by  narcotic  substances,  or  follow  a  previous  state  of  abnormal  activity  of 
the  brain,  such  as  Delirium  (§  715).     Between  these  two  conditions,  however, 
every  gradation  may  be  seen;  as  in  the  gradually-increasing  torpor  which  results 
from  slow  effusion  within   the   cranium,  the   gradual    loss  of  susceptibility  to 

1  The  careful  study  of  the  Epistles  of  St.  Paul  will  show  this  to  be  the  dominant  idnt 
of  this  Apostle's  teachings.  Under  the  name  of  "  the  Law,"  he  continually  refers  to  the 
spirit  of  bondage  or  external  coercion,  which  "was  the  schoolmaster  to  bring  us  to 
Christ;"  whilst  under  the  desigation  of  "  the  Gospel"  he  obviously  desires  to  express  that 
spirit  of  internal  freedom  or  self-direction,  which  is  the  source  of  all  that  is  truly  noble 
in  the  Christian  character. 

39 


FUNCTIONS    OF   THE   CEKEBRO-SPINAL   NERVOUS   SYSTEM. 

external  impressions  which  is  observed  after  an  over-dose  of  a  narcotic,  and  the 
intensification  of  ordinary  sleep  which  is  consequent  upon  extreme  previous 
fatigue.  It  is  a  matter  of  doubt,  however,  whether  the  suspension  of  sensorial 
consciousness  is  equally  complete  as  regards  internal  or  Cerebral  changes;  for 
some  are  of  opinion  that,  even  in  the  most  profound  sleep,  we  still  dream,  although 
we  may  not  remember  our  dreams  ;  whilst  others  (and  among  these  the  Author 
would  rank  himself)  consider  that  dreaming  is  a  mark  of  imperfect  sleep,  and 
that,  in  profound  ordinary  sleep,  the  Cerebrum,  in  common  with  the  Sensory 
Ganglia,  is  in  a  state  of  complete  functional  inactivity.  When  Dreaming  takes 
place,  there  is  usually  a  less  complete  exclusion  of  sensory  impressions,  although 
the  perceptive  consciousness  may  be  entirely  suspended ;  so  that  the  course  of 
the  dream  may  be  influenced  by  them,  although  the  mind  is  not  conscious  of 
them  as  such  (§  692).  If  this  be  the  true  account  of  the  case,  we  may  consider 
that,  in  profound  Sleep,  the  functional  activity  of  the  Cerebrum  and  of  the 
Sensory  Ganglia  is  alike  suspended;  but  that  in  Dreaming,  the  Cerebrum  is 
partially  active,  whilst  the  Sensorium  is  in  such  a  condition  of  receptivity  for 
Cerebral  (subjective)  impressions  that  the  mind  becomes  directly  conscious  of 
them,  though  it  only  becomes  conscious  of  (objective)  impressions  made  upon 
the  Organs  of  Sense,  after  their  influence  has  been  transmitted  through  it  to  the 
Cerebrum,  and  has  been,  as  it  were,  reflected-back  by  that  organ.  It  is  in  fact, 
by  their  influence  upon  the  current  of  ideas,  and  not  by  their  power  of  exciting 
sensations,  that  we  recognize  their  operation  under  such  circumstances. 

681.  The  state  of  Sleep  is  one  to  which  there  is  beyond  doubt  a  periodical 
tendency;  for,  when  the  waking  activity  has  continued  during  a  considerable 
proportion  of  the  twenty-four  hours,  a  sense  of  fatigue  is  usually  experienced, 
which  indicates  that  the  brain  requires  repose ;  and  it  is  only  under  some  very 
strong  physical  or  moral  stimulus,  that  the  mental  energy  can  be  sustained 
through  the  whole  cycle.  In  fact,  unless  some  decidedly  abnormal  condition  of 
the  Cerebrum  be  induced  by  the  protraction  of  its  functional  activity,  Sleep  will 
at  last  supervene,  from  the  absolute  inability  of  the  organ  to  sustain  any  further 
demands  upon  its  energy,  even  in  the  midst  of  opposing  influences  of  the  most 
powerful  nature.1  That  the  strongest  Volitional  determination  to  remain  awake, 
is  forced  to  give-way  to  Sleep,  when  this  is  required  by  the  exhaustion  of  nervous 
power,  must  be  within  the  experience  of  every  one  ;  and  the  only  way  in  which 
the  Will  can  even  retard  its  access,  is  by  determinately  fixing  the  consciousness 
upon  some  definite  object,  and  resisting  every  tendency  in  the  thoughts  to  wander 
from  this.  It  does  not  appear  to  be  of  any  consequence,  whether  this  exhaus- 
tion be  produced  by  the  active  exercise  of  volition,  reflection,  emotion,  or  simple 
sensation  ;  still  we  find  that  the  volitional  direction  of  the  thoughts,  in  a  course 
different  from  that  in  which  they  tend  spontaneously  to  flow,  is  productive  of  far 
more  exhaustion  than  the  automatic  activity  of  the  mind  (§  647) ;  whilst,  on  the 
other  hand,  the  excess  of  automatic  activity,  whether  as  regards  the  intellectual 

1  Thus  it  is  on  record,  that,  during  the  heat  of  the  battle  of  the  Nile,  some  of  the 
over-fatigued  boys  fell  asleep  upon  the  deck :  and  during  the  recent  attack  upon  Rangoon, 
the  Captain  of  one  of  the  war-steamers  most  actively  engaged,  worn-out  by  the  excess  of 
continued  mental  tension,  fell  asleep,  and  remained  perfectly  unconscious  for  two  hours, 
within  a  yard  of  one  of  his  largest  guns,  which  was  being  worked  energetically  during  the 
whole  period. — So  even  the  severest  bodily  pain  yields  before  the  imperative  demand  occa- 
sioned by  the  continued  exhaustion  of  the  powers  of  the  sensorial  centres;  thus  Damiens 
slept  upon  the  rack,  during  the  intervals  of  his  cruel  sufferings ;  the  North  American 
Indian  at  the  stake  of  torture  will  go  to  sleep  on  the  least  remission  of  agony,  and  will 
slumber  until  the  fire  is  applied  to  awaken  him ;  and  the  Medical  Practitioner  has  fre- 
quent illustrations  of  the  same  fact. — That  the  continued  demand  for  muscular  activity 
is  not  incompatible  with  the  access  of  sleep,  is  obvious  from  what  has  been  already  said 
of  the  persistence  of  the  automatic  movements  in  that  condition  ($  514) ;  it  is  well  known 
that  previously  to  the  shortening  of  the  hours  of  work,  factory  children  frequently  fell 
asleep  whilst  attending  to  their  machines,  although  well  aware  that  they  should  incur 
•evere  punishment  by  doing  so. 


OF    SLEEP    AND    SOMNAMBULISM.  611 

operations  or  emotional  excitement,  tends  to  prevent  sleep.  This  is  particularly 
the  case  when  the  feelings  are  strongly  interested  ;  thus  the  strong  desire  to 
work-out  a  result,  or  to  complete  the  survey  of  a  subject,  is  often  sufficient  to 
keep-up  the  intellectual  activity  as  long  as  may  be  requisite,  (a  state  of  restless- 
ness, however,  being  often  induced,  which  prevents  the  access  of  sleep  for  some 
time  longer) ;  so,  again,  anxiety  or  distress  is  a  most  frequent  cause  of  wakeful- 
ness  ]  and  it  is  generally  to  be  observed  that  the  state  of  suspense  is  more  opposed 
to  the  access  of  sleep,  than  the  greatest  joy  or  the  direst  calamity  when  certainty 
has  been  attained.1  But  although  an  excess  of  automatic  activity  is  opposed,  so 
long  as  it  continues,  to  the  access  of  sleep,  yet  it  cannot  be  long  protracted  without 
occasioning  an  extreme  exhaustion  of  nervous  power,  which  necessitates  a  long 
period  of  tranquillity  fur  its  complete  restoration. 

682.  Whilst,  however,  the  necessity  for  Sleep  arises  out  of  the  state  of  the 
nervous  system  itself,  there  are  certain    external    conditions  which  favour  its 
access;    and  these,   in  common  parlance,   are   termed   its  predisposing  causes. 
Among  the  most  powerful  of  these,  is  the  absence  of  sensorial  impressions ;  thus, 
darkness  and  silence  usually  promote  repose ;  and  the  cessation  of  the  sense  of 
muscular  effort,  which  takes-place  when  we  assume  a  position  that  is  sustained 
without  it,  is  no  less  conducive  to  slumber.     There  are  cases,  however,  in  which 
the  continuance  of  an  accustomed  sound  is  necessary,  instead  of  positive  silence, 
the  cessation  of  the  sound  being  a  complete  preventive  of  sleep ;  thus  it  happens 
that  persons  living  in  the  neighbourhood  of  the  noisiest  mills  or  forges,  cannot 
readily  sleep  elsewhere.     Such  cases  are  referable,  either  to  the  influence  of 
habit,  which  causes  the  attention  of  the  individual  to  be  more  attracted  by  the 
suspension  of  the  sound  than  by  its  continuance ;  or  to  the  fact  that  the  mono- 
tonous repetition  of  sensorial  impressions  is  often  more  favourable  to  sleep  than 
their  complete  absence.     Thus  it  is  within  the  experience  of  every  one,  that  the 
droning  voice  of  a  heavy  reader  on  a  dull  subject,  is  often  a  most  effectual  hypno- 
tic; in  like  manner,  the  ripple  of  the  calm  ocean  on  the  shore,  the  sound  of  a 
distant  waterfall,  the  rustling  of  foliage,  the  hum  of  bees,  and  similar  impres- 
sions upon  the  auditory  sense,  are  usually  favourable  to  sleep ;  and  the  muscular 
and  tactile  senses  may  be  in  like  manner  affected  by  an  uniform  succession  of 
gentle  movements,  as  we  see  in  the  mode  in  which  nurses  'hush-off'  infants,  or 
in  the  practice  of  gently  rubbing  some  part  of  the  body,  which  has  been  success- 
fully employed  by  many  who  could  not  otherwise  compose  themselves  to  sleep. 
The  reading  of  a  dull  book  acts  in  the  same  mode  through  the  visual  sense ;  for 
the  eyes  wander-on  from  line  to  line,  and  from  page  to  page,  receiving  a  series 
of  sensorial  impressions  which  are  themselves  of  a  very  monotonous  kind,  and 
which  only  tend  to  keep  the  attention  alive,  in  proportion  as  they  excite  inte- 
resting ideas. 

683.  In  these  and  similar  cases,  the  influence  of  external  impressions  would 
seem  to  be  exerted  in  withdrawing  the  mind  from  the  distinct  consciousness  of 
its  own  operations  (the  loss  of  which  is  the  transition-state  towards  that  of  com- 
plete unconsciousness),  and  in  suspending  the  directing  power  of  the  Will.     And 
this  is  the  case,  even  where  the  attention  is  in  the  first  instance  voluntarily 
directed  to  them ;  as  in  some  of  the  plans  which  have  been  recommended  for  the 
induction  of  sleep,  when  there  exists  no  spontaneous  disposition  to  it.     In  other 
methods,  the  attention  is  fixed  upon  some  internal  train  of  thought,  which,  when 
once  set-going,  may  be  carried-on  automatically ;  such  as  counting  numbers,  or 
repeating  a  French,  Latin,  or  Greek  verb.     In  either  case,  when  the  sensorial 
consciousness  has  been  once  steadily  fixed,   the  monotomy  of  the  impression 
(whether  received  from  the  Organs  of  Sense,  or  from  the  Cerebrum)  tends  to 

1  Thus  it  is  a  common  observation,  that  criminals  under  sentence  of  death,  sleep  badly, 
so  long  as  they  entertain  any  hopes  of  a  reprieve  ;  but  when  once  they  are  satisfied  that 
their  death  is  inevitable,  they  usually  sleep  more  soundly,  and  this  even  on  the  very  last 
night  of  their  lives. 


612  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

retain  it  there ;  so  that  the  Will  abandons,  as  it  were,  all  control  over  tho  ope- 
rations of  the  mind,  and  allows  it  to  yield  itself  up  to  the  soporific  influence. 
This  last  method  is  peculiarly  effectual,  when  the  restlessness  is  dependent  upon 
some  mental  agitation,  provided  that  the  Will  has  power  to  withdraw  the  thoughts 
from  the  exciting  subject,  and  to  reduce  them  to  the  tranquillizing  state  of  a 
mere  mechanical  repetition. 

684.  The  access  of  Sleep  is  sometimes  quite  sudden;  the  individual  passing 
at  once  from  a  state  of  complete  mental  activity  to  one  of  entire  torpor.  More 
generally,  however,  it  is  gradual ;  and  various  intermediate  phases  may  be 
detected,  some  of  which  bear  a  close  resemblance  t€  the  state  of  Reverie,  whose 
peculiar  nature  has  been  already  described  (§  671).  The  same  may  be  said  with 
regard  to  the  transition  from  the  state  of  Sleep  to  that  of  wakeful  activity ;  and 
this  also  may  be  sudden  and  complete,  although  it  usually  consists  of  a  succes- 
sion of  stages,  —  the  complete  consciousness  of  the  individual's  relation  to  the 
external  world,  and  the  power  of  directing  his  thoughts  and  actions  to  any  sub- 
ject about  which  he  may  be  required  to  exert  himself,  being  the  last  to  return  to 
him.  There  may  be  a  rapid  alternation  of  these  different  states ;  the  loss  and 
recovery  of  the  waking  consciousness  being  many  times  repeated  in  the  course 
of  a  few  minutes,  when  the  circumstances  are  such  as  to  prevent  the  access  of 
profound  sleep  by  the  recurrence  of  sensory  impressions ;  as  when  a  man  on 
horseback,  wearied  from  want  of  rest,  lapses  at  every  moment  into  a  dozing  state, 
from  which  the  loss  of  the  balance  of  his  body  as  frequently  and  suddenly 
arouses  him;  or  when  a  man  going  to  sleep  in  a  sitting  posture,  gradually  loses 
the  support  of  the  muscles  which  keep  his  head  erect,  his  head  droops  by  degrees 
and  at  last  falls  forwards  on  his  chest,  and  the  slight  shock  thence  ensuing  par- 
tially arouses  and  restores  his  voluntary  power,  which  again  raises  the  head. 
Similar  fluctuations  occur  in  the  sensory  perceptions ;  and  these  may  be  often 
artificially  induced  by  very  simple  means.  "  We  find,  for  example,  one  con- 
dition of  sleep  so  light,  that  a  question  asked  restores  consciousness  enough  for 
momentary  understanding  and  reply;  and  it  is  an  old  trick  to  bring  sleepers  into 
this  state,  by  putting  the  hand  into  cold  water,  or  producing  some  other  sensa- 
sation,  not  so  active  as  to  awaken,  but  sufficient  to  draw  the  mind  from  a  more 
profound  to  a  lighter  slumber.  This  may  be  often  repeated,  sleep  still  going  on ; 
but  make  the  sound  louder  and  more  sudden,  and  complete  waking  at  once 
ensues.  The  same  with  other  sensations.  Let  the  sleeper  be  gently  touched, 
and  he  shows  sensibility,  if  at  all,  by  some  slight  muscular  movement.  A  ruder 
touch  excites  more  disturbance  and  motion,  and  probably  changes  the  current  of 
dreaming;  yet  sleep  will  go  on,  and  it  often  requires  a  rough  shaking,  particu- 
larly in  young  persons,  before  full  wakefulness  can  be  obtained."  *  *  *  "  It  is 
certain  that  the  faculties  of  sensibility  and  volition  are  often  unequally  awakened 
from  sleep.  The  case  may  be  stated,  familiar  to  many,  of  a  person  sleeping  in 
an  upright  posture,  with  the  head  falling  over  the  breast;  in  whom  sensibility  is 
suddenly  aroused  by  some  external  impression,  but  who  is  unable,  for  a  certain 
time,  to  raise  his  head,  though  the  sensation  produced  by  this  delay  of  voluntary 
action  is  singularly  distressing."  These  various  cases,  it  is  justly  remarked  by 
Sir  H.  Holland,1  depending  severally  on  the  intensity  of  sleep,  and  on  the  kind 
and  degree  of  the  external  exciting  causes,  will  be  found  to  explain  many  of 
those  so-called  Mesmeric  phenomena,  which  are  offered  to  us  under  a  widely  dif- 
ferent interpretation.  And  it  may  be  here  remarked,  that  among  those  inter- 
mediate states  between  sleep  and  waking,  which  either  occur  spontaneously,  or 
can  be  induced  in  numerous  individuals  by  very  simple  processes  (§§  672,  693), 
there  are  several  which  exhibit  peculiarities  that  are  not  in  themselves  in  the 
least  degree  less  remarkable,  than  are  those  which  are  regarded  with  so  much 
wonder  by  the  uninformed  observer,  when  induced  by  the  asserted  Mesmeric  in- 
fluence, and  paraded  as  specimens  of  its  power.  (See  §  696,  note.} 

'  See  his  excellent  Chapter  on  '  Sleep,'  from  which  the  above  extracts  are  taken,  in 
Ms  "  Medical  Notes  and  Reflections,"  and  his  "Chapters  on  Mental  Physiology." 


OF    SLEEP    AND     SOMNAMBULISM.  613 

685.  It  is  unquestionable  that  the  supervention  of  Sleep  may  be  promoted  by 
the  strong  previous  expectation  of  it;  and  this  is  true,  not  merely  of  ordinary 
sleep,  but  of  the  states  of  artificial  Reverie  and  Somnambulism  formerly  described. 
Every  one  knows  the  influence  of  habit,  not  only  in  regard  to  l  time/  but  also  as 
to   *  place  and  circumstance/  in  predisposing  to  Sleep.     Thus,  the  celebrated 
pedestrian  Capt.  Barclay,  when  accomplishing  his  extraordinary  feat  of  walking 
1000  miles  in  as  many  successive  hours,  obtained  at  last  such  a  mastery  over 
himself,  that  he  fell  asleep  the  instant  he  lay  down.     And  the  sleep  of  soldiers, 
sailors,  and  others,  who  are  prevented  by  '  duty '  from  obtaining  regular  periods 
of  repose,  but  are  obliged  to  take  their  rest  at  short  intervals,  may  be  almost  said 
to  come   to  command;    nothing   more   being  necessary  to  induce  it,  than  the 
placing:  the  body  in  an  easy  position,  and  the  closure  of  the  eyes.     It  is  related 
that  the  Abbe"  Farie,  who  acquired  notoriety  through  his  power  of  inducing  som- 
nambulism, was  accustomed  merely  to  place  his  patient  in  an  arm-chair,  and 
then,  after  telling  him  to  shut  his  eyes  and  collect  himself,  to  pronounce  in  a 
strong  voice  and  imperative  tone  the  word  "  dormez,"  which  was  usually  success- 
ful.    The  Author  has  had  frequent'opportunities  of  satisfying  himself,  that  the 
greater  success  which  attends  the  *  hypnotic '  mode  of  inducing  somnambulism 
(§  695),  in  the  hands  of  Mr.  Braid,  its  discoverer,  than  in  that  of  others,  partly 
lies  in  the  mental  condition  of  his  subjects,  who  come  to  him  for  the  most  part 
under  the  confident  expectation  of  its  production,  and  are  further  assured  by  a 
man  of  very  determined  will,  that  it  cannot  be  resisted.1     And  it  is  one  of  the 
most  curious  phenomena  of  the  '  biological '  state  (§  672),  that,  in  many  subjects 
at  least,  sleep  may  be  induced  in  a  minute  or  less,  by  the  positive  assurance, 
with  which  the  mind  of  the  individual  becomes  possessed,  that  it  will  and  must 
supervene. 

686.  The  influence  of  previous  mental  states  is  yet  more  remarkable,  in  deter- 
mining the  effects  produced  upon  the  sleeper  by  different  sensory  impressions. 
The  general  rule  is,  that  habitual  impressions  of  any  kind  have  much  less  effect 
in  arousing  the  slurnberer,  than  those  of  a  new  or  unaccustomed  character.     An 
amusing  instance  of  this  kind  has  been  related  to  the  Author,  which,  even  if  not 
literally  true,  serves  extremely  well  as  an  illustration  of  what  is  unquestionably 
the  ordinary  fact.     A  gentleman  who  had  taken  his  passage  on  board  a  ship  of 
war,  was  aroused  on  the  first  morning  by  the  report  of  the  morning  gun,  which 
chanced  to  be  fired  just  above  his  berth ;  the  shock  was  so  violent  as  to  cause  him 
to  jump  out  of  bed.     On  the  second  morning,  he  was  again  awoke,  but  this  time 
he  merely  started  and  sat-up  in  bed  ;  on  the  third  morning,  the  report  had  simply 
the  effect  of  causing  him  to  open  his  eyes  for  a  moment,  and  turn  in  his  bed : 
on  the  fourth  morning,  it  ceased  to  affect  him  at  all;  and  his  slumbers  continued 
to  be  undisturbed  by  the  report,  so  long  as  he  remained  on  board.     It  often 
happens  that  sleep  is   terminated   by  the  cessation   of  an    accustomed  sound, 
especially  if  this  be  one  whose  monotony  or  continuous  repetition  has  been  the 
original  inducement  to  repose.     Thus,  a  person  who  has  been  read  or  preached  to 
sleep,  will  awake,  if  his  slumber  be  not  very  profound,  on  the  cessation  of  the 
voice ;  and  a  naval  officer,  sleeping  beneath  the  measured  tread  of  the  watch  on 
deck,  will  awake  if  that  tread  be  suspended.  — In  this  latter  case,  the  influence 
of  the  simple  cessation  of  the  impression  will  be  augmented  by  the  circumstance 
next  to  be  alluded-to,  which  has  received  too  little  attention  from  writers  on  this 
subject,  but  which  is  of  peculiar  interest  both  in  a  physiological  and  psychologi- 
cal point  of  view,  and  is  practically  familiar  to  almost  every  one. 

687.  The  awakening  power  of  sensory  impressions  is  greatly  modified  by  our 
habitual  state  of  mind  in  regard  to  them.     Thus,  if  we  are  accustomed  to  attend 

1  A  very  amusing  instance  in  which  Sleep,  having  been  previously  induced  by  the  ordi- 
nary 'mesmeric'  and  then  by  the  'hypnotic'  processes,  was  brought-on  by  the  simple 
belief  that  a  new  process  was  being  put  in  practice,  will  be  found  in  the  "  Brit,  and  For 
Med.  Rev.,"  vol.  six,  p.  477. 


614  FUNCTIONS   OF   THE   CEREERO-SPINAL   NERVOUS    SYSTEM. 

to  these  impressions,  and  our  perception  of  them  is  thus  increased  in  acuteness, 
we  are  much  more  easily  aroused  by  them,  than  we  are  by  others  which  are  in 
themselves  much  stronger,  but  which  we  have  been  accustomed  to  disregard. 
Thus,  most  sleepers  are  aroused  by  the  sound  of  their  own  names  uttered  in  a 
low  tone,  when  it  requires  a  much  louder  sound  of  a  different  description  to  pro- 
duce any  manifestation  of  consciousness.  The  same  thing  is  seen  in  comatose 
states;  a  patient  being  often  found  Capable  of  being  momentarily  aroused  by 
shouting  his  name  into  his  ear,  when  no  other  sound  produces  the  least  effect. — 
The  following  circumstance,  communicated  to  the  Author  by  the  late  Sir  Edward 
Codrington,  is  a  most  apposite  illustration  of  this  principle.  When  a  young 
man,  he  was  serving  as  signal-lieutenant  under  Lord  Hood,  at  the  time  when  the 
French  fleet  was  confined  in  Toulon  harbour;  and  being  desirous  of  obtaining 
the  favourable  notice  of  his  commander,  he  devoted  himself  to  his  duty  (that  of 
watching  for  signals  made  by  the  look-out  frigates)  with  the  greatest  energy  and 
perseverance,  often  remaining  on  deck  nineteen  hours  out  of  the  twenty-four, 
with  his  attention  constantly  directed  towards  this  one  object.  During  the  few 
hours  which  he  spent  in  repose,  his  sleep  was  so  profund,  that  no  noise  of  an 
ordinary  kind,  however  loud,  would  awake  him ;  and  it  used  to  be  a  favourite 
amusement  with  his  comrades,  to  try  various  experiments  devised  to  test  the 
soundness  of  his  sleep.  But  if  the  word  l  signal '  was  even  whispered  in  his 
ear,  he  was  instantly  aroused,  and  fit  for  immediate  duty. — The  influence  of 
habitual  attention  is  shown  as  much  in  the  effect  produced  by  the  cessation,  as 
in  that  of  the  occurrence,  of  sensory  impressions.  Thus  in  the  case  of  the  naval 
officer  aroused  by  the  suspension  of  the  measured  tread  of  the  watch  over  his 
head,  the  knowledge  possessed  during  the  waking  state,  that  this  suspension  is 
either  an  act  of  negligence  which  requires  notice,  or  indicates  some  unusual 
occurrence,  doubtless  augments  the  effect  which  the  discontinuance  of  the  sound 
would  of  itself  produce.  \ 

688.  It  is  not  requisite,  however,  that  the  sound  should  be  one  habitually 
attended-to  during  the  hours  of  watchfulness  ]  for  it  is  sufficient  if  it  be  one  on 
which  the  attention  has  been  fixed  as  that  at  which  the  slumberer  is  to  arouse 
himself.  Thus  the  medical  man,  even  in  his  first  profound  sleep  after  a  fatiguing 
day's  work,  is  aroused  by  the  first  stroke  of  the  clapper  of  his  night-bell ;  and 
to  those  who  are  accustomed  to  rise  every  morning  at  the  sound  of  an  alarum- 
clock,  the  frequency  and  regularity  of  the  occurrence  do  not  diminish,  but  rather 
increase,  the  readiness  with  which  it  produces  its  effect,  provided  that  the  warn- 
ing be  promptly  obeyed.  On  this  usually  depends  the  efficiency  of  the  awakening 
sound;  if  it  be  disregarded,  as  a  thing  to  which  there  is  no  occasion  to  give  heed, 
it  very  soon  ceases  to  produce  any  effect,  the  entire  peal  not  being  sufficient  to 
awake  the  sleeper ;  whilst,  on  the  other  hand,  the  first  stroke  is  enough  to  break 
the  repose  of  him  who  is  impressed  with  the  effectual  desire  of  profiting  by  the 
warning.  And  thus  it  may  happen  that,  of  two  persons  in  the  same  room,  either 
shall  be  at  once  aroused  by  a  sound  which  produces  no  disturbance  in  the  slum- 
bers of  the  other.  To  this  influence  of  previous  impressions,  whether  habitual, 
or  but  once  forcibly  made,  we  are  also  to  refer  the  spontaneous  termination  of 
the  state  of  sleep  at  particular  times,  without  any  sensorial  excitement  from  ex- 
ternal impressions.  Thus,  many  persons  who  are  accustomed  to  rise  at  a  parti- 
cular hour,  wake  regularly  at  that  hour,  whether  they  have  gone  to  rest  early  or 
late;  so  that  the  act  of  spontaneously  awakening  is  no  proof  that  the  desirable 
amount  of  repose  has  been  obtained.  But  what  is  more  remarkable  is,  that  many 
individuals  have  the  power  of  determining,  at  the  time  of  going  to  rest,  the  hour 
at  which  they  shall  rise,  so  as  to  awake  from  a  profound  sleep  at  the  precise  time 
fixed-upon.  In  others,  however,  the  desire  to  rise  at  a  particular  hour  only  in- 
duces a  state  of  restlessness  throughout  the  night,  destroying  the  soundness  of 
the  slumbers :  the  individual  awakes  many  times  in  the  night,  with  the  belief 
that  the  hour  is  past,  and  very  possibly  oversleeps  it  after  all,  the  system  being 
wuru-out  by  the  need  of  repose. 


OF    SLEEP    AND    SOMNAMBULISM.  615 

689.  The  Amount  of  Sleep  required  by  Man  is  affected  by  so  many  conditions, 
especially  age,  temperament,  habit,  and  previous  exhaustion,  that  no  general  rule 
can  be  laid-down  on  the  subject. — The  condition  of  the  foetus  in  utero  may  be 
regarded  as  one  of  continual  slumber;  the  apparatus  of  animal  life  being  com- 
pletely secluded  from  all  stimuli  which  could  arouse  it  into  activity,  whilst  the 
energy  of  the  organic  functions  is  entirely  directed  to  the  building-up  of  the 
fabric.  On  its  first  entrance  into  the  world,  the  infant  continues  to  pass  the 
greater  part  of  its  time  in  slumber;  and  this  is  particularly  to  be  noticed  in 
cases  of  premature  birth,  the  seven  months'  child  seeming  to  awake  only  for  the 
purpose  of  receiving  food,  and  giving  but  little  heed  to  external  objects,  whilst 
even  the  eight  months'  child  is  considerably  less  alive  to  sensory  impressions 
than  one  born  at  the  full  time.  The  excess  of  activity  of  the  constructive  over 
the  destructive  operations,  which  characterizes  the  whole  period  of  infancy,  child- 
hood, and  adolescence  (CHAP,  xvm.),  requires  that  a  larger  proportion  of  the 
diurnal  cycle  shall  be  passed  in  sleep  (during  which  the  former  may  be  carried- 
on  without  hindrance),  than  is  requisite  when  adult  age  has  been  attained,  the 
two  sets  of  changes  being  then  balanced ;  and  the  amount  of  sleep  to  which  the 
system  shows  itself  disposed,  gradually  diminishes  from  three-fourths  to  one- 
half,  and  from  one-half  to  one-third,  or  even  to  one-quarter,  of  the  twenty-four 
hours.  It  is  to  be  noticed  that  the  sleep  of  children  or  young  persons  is  not 
only  longer  than  that  of  adults,  but  is  also  more  profound.  On  the  other  hand, 
as  age  advances,  and  the  bodily  and  mental  activity  of  the  waking  state  decreases, 
a  smaller  amount  of  sleep  suffices;  or,  if  the  slumber  be  protracted,  it  is  usually 
less  deep  and  refreshing.  It  may  be  noticed,  however,  that  very  old  persons 
usually  pass  a  large  proportion  of  their  time  in  sleep,  or  rather  in  a  sort  of  heavy 
doze,  especially  after  meals ;  as  if,  in  consequence  of  the  want  of  energy  of  their 
nutritive  operations,  a  very  long  period  of  repose  is  necessary  to  repair  the  waste 
which  takes  place  during  their  short  period  of  activity. — In  regard  to  the  influ- 
ence of  temperament,  it  may  be  remarked  that  a  plethoric  habit  of  body,  sus- 
tained by  full  diet,  usually  predisposes  to  sleep,  provided  that  the  digestive  powers 
be  in  a  vigorous  condition ;  persons  of  this  constitution  frequently  pass  nine  or 
ten  hours  in  slumber,  and  maintain  that  they  cannot  be  adequately  refreshed  by 
less.  On  the  other  hand,  thin,  wiry  people,  in  whom  the  '  nervous'  temperament 
predominates,  usually  take  comparatively  little  sleep,  notwithstanding  the  greater 
activity  of  their  nervous  system  when  they  are  awake ;  but  their  slumber,  while 
it  lasts,  is  generally  very  deep.  Persons  of  '  lymphatic'  temperament,  heavy, 
passionless  people,  who  may  be  said  to  live  very  slowly,  are  usually  great  sleepers  ; 
but  this  is  rather  because,  through  the  dulness  of  their  perceptions,  they  are  less 
easily  kept  awake  by  sensorial  or  mental  excitement,  than  because  they  really 
require  a  prolonged  cessation  of  activity.  As  they  are  half  asleep  during  the 
waking  state,  so  would  it  appear  that  the  constructive  operations  must  be  far 
from  active  while  they  are  asleep,  so  little  do  they  seem  restored  by  the  repose. — 
Tbe  amount  of  sleep,  cseteris  paribus,  required  by  individuals,  is  very  greatly 
influenced  by  habit;  and,  contrary  to  what  we  might  anticipate,  we  find  that  the 
briefest  sleepers  have  usually  been  men  of  the  greatest  mental  activity.  Thus 
Frederick  the  Great  and  John  Hunter  are  said  to  have  only  required  five  hours' 
sleep  out  of  the  twenty-four ;  and  General  Elliot,  celebrated  for  his  defence  of 
Gibraltar,  is  recorded  not  to  have  slept  more  than  four  hours  out  of  the  twenty- 
four.  It  may  be  doubted  whether  it  would  be  possible  for  any  one  to  sustain  a 
life  of  vigorous  exertion  upon  a  smaller  allowance  than  this;  and  the  general 
fact  is,  that  from  six  to  eight  hours  of  repose,  out  of  every  twenty-four,  are  re- 
quired to  keep  the  system  of  an  adult  in  a  state  of  healthful  activity.  Thu 
influence  of  habit  may  be  brought  to  bear  on  the  protraction,  as  well  as  on  tho 
abbreviation,  of  the  usual  period.  Thus  Quin,  the  celebrated  actor,  could  slum- 
ber for  twenty-four  hours  successively;  and  Dr.  Reid,  the  metaphysician,  coul  1 
jake  as  much  food,  and  afterwards  as  much  sleep,  as  were  sufficient  £«•  two 


016  FUNCTIONS    OF    THE    CEREBRO-SPIXAL   NERVOUS    SYSTEM. 

days. — It  is  needless  to  dwell  upon  the  obvious  fact,  that,  other  things  being 
equal,  the  amount  of  sleep  required  by  man  is  proportional  to  the  amount  oj  men- 
tal exertion  put-forth  during  the  waking  hours ;  since  this  is  an  obvious  result 
of  what  has  been  laid-down  as  the  cause  of  the  demand  for  sleep.  It  may  be 
remarked,  however,  that  we  must  not  measure  the  amount  of  sleep  by  its  ihira- 
tian  alone  :  since  its  intensity  is  a  matter  of  equal  importance.  The  light  slum- 
ber which  is  disturbed  by  the  slightest  sounds,  cannot  be  as  renovating  as  the 
profound  sopor  of  those  whom  no  ordinary  noise  will  awake. 

690.  There  are  certain  states  of  the  Encephalic  centres,  in  which  there  is  an 
entire  absence  of  Sleep;  and  this  may  continue  for  many  days,  or  even  for  weeks 
or  months.     Insomnia  is,  for  instance,  one  of  the  characteristics  of  acute  Mania, 
and  may  also  exist  in  various  forms  of  Monomania  ;  it  is  usually,  also,  one  of  the 
symptoms  of  incipient  meningeal  inflammation ;  and  it  may  constitute  a  specific 
disease  in  itself.     In  all  these  cases,  however,  the  preponderance  of  the  destructive 
processes  over  the  constructive  manifests  itself,  sooner  or  later,  in  the  exhaustion 
of  the  mental  and  bodily  powers.     Thus  Mania,  when  prolonged  or  frequently 
recurring,  subsides  into  Dementia;  and,  if  it  continue  for  any  length  of  time,  is 
sure  to  be  followed  by  a  great  sense  of  wretchedness  and  prostration,  frequently 
accompanied  by  continual  restlessness.     Such  effects,  too,  in  a  less  aggravated 
degree,  result  from  habitual  deficiency  of  sleep;   whether  this  be  due  to  emo- 
tional excitement,  which  keeps  repose  at  bay,  or  to  a  voluntary  determination  to 
keep  the  intellect  in  activity.     This  is  a  very  common  occurrence  among  indus- 
trious students,  who,  with  a  laudable  desire  for  distinction,  allow  themselves  less 
than  the  needed  quantum  of  repose.     Headache,  tension,  heat,  throbbing,  and 
various  other  unpleasant  sensations  in  the  head,  give  warning  that  the  brain  is 
being  overtasked;  and  if  this  warning  be  not  taken,  sleep,  which  it  was  at  first 
difficult  to  resist,  becomes  even  more  difficult  to  obtain ;  a  state  of  general  rest- 
lessness and  feverish  excitement  are  induced ;  and  if,  in  spite  of  this,  the  effort 
be  continued,  serious  consequences,  in  the  form  of  cerebral  inflammation,  apo- 
plexy, paralysis,  fever,  insanity,  or  loss  of  mental  power,  more  or  less  complete, 
are  nearly  certain  to  be  induced.     Some  individuals  can  sustain  such  an  effort 
much  longer  than  others,  but  it  is  a  great  mistake  to  suppose  that  they  are  not 
equally  injured  by  it;  in  fact,  being  possessed  with  the  belief  that  they  are  not 
suffering  from  the  exertion,  they  frequently  protract  it,  until  a  sudden  and  com- 
plete prostration  gives  a  fearful  demonstration  of  the  cumulative  effects  of  the 
injurious  course  in  which  they  have  been  persevering.      Those,  consequently, 
who  are  earlier  forced  to  give-way,  are  frequently  capable  of  accomplishing  more 
in  the  end. — In  regard  to  the  degree  of  protraction  of  sleep  which  is  consistent 
with  a  healthy  state  of  the  system  in  other  respects,  it  is  difficult  to  speak  with 
certainty.     Of  the  numerous  well-authenticated  instances  on  record,1  in  which 
sleep  has  been  continuously  prolonged  for  many  days  or  even  weeks,  it  is  enough 
here  to  state  that  they  cannot  be  regarded  as  examples  of  natural  sleep;  the  state 
of  such  persons  being  more  closely  allied  to  hysteric  coma.     An  unusual  ten- 
dency to  ordinary  sleep  generally  indicates  a  congested  state  of  the  brain,  tending 
to  apoplexy;  and  it  has  been  stated  that  apoplexy  has  been  actually  induced  by 
the  experimental  attempt  to  ascertain  how  large  a  proportion  of  the  diurnal  cycle 
might  be  spent  in  sleep. — Thus,  on  either  side,  inattention  to  the  dictates  of 
Nature,  in  respect  to  the  amount  of  sleep  required  for  the  renovation  of  the  sys- 
tem, becomes  a  source  of  disease,  and  should  therefore  be  carefully  avoided. 

691.  Dreaming. — We  have  hitherto  spoken  of  sleep  in  its  most  complete  or 
profound  form;  that  is,  the  state  of  complete  unconsciousness.     But  with  the 
absence  of  consciousness  of  external  things,  there   may  be  a  state  of  mental 
activity,  of  which  we  are  more  or  less  distinctly  cognizant  at  the  time,  and  of 
which  our  subsequent  remembrance  in  the  waking  state  varies  greatly  in  com- 

1  Such,  for  example,  as  that  of  Samuel  Chilton  ("  Phil.  Trans.,"  1694),  and  that  of  Mary 
Lyall  ("Trans,  of  Roy.  Soc.  ofEdinb.,"  1818). 


OF     SLEEP    AND     SOMNAMBULISM.  617 

pleteness.     The  chief  peculiarity  of  this  state  of  dreaming  appears  to  be,  that 
there  is  an  entire  suspension  of  Volitional  control  over  the  current  of  thought, 
which  flows-on  automatically,  sometimes  in  a  uniform,  coherent  order,  but  more 
commonly  in  a  strangely-incongruous  sequence.     The  former  is  most  likely  to 
occur,  when  the  mind  simply  takes-up  the  train  of  thought  on  which  it  had 
been  engaged  during  the  waking-hours,  not  long  previously  ;   and  it  may  even 
happen  that,  in  consequence  of  the  freedom  from  distraction  resulting  from  the 
suspension  of  external  influences,  the  Reasoning  processes  may  thus  be  carried-on 
during  sleep  with  unusual  vigour  and  success,  and  the  Imagination  may  develope 
new  and  harmonious  forms  of  beauty.1     The  more  general  fact  is,  however,  that 
there  is  an  entire  want  of  any  ostensible  coherence  between  the  ideas  which  suc- 
cessively present  themselves  to  the  consciousness;   and  yet  we  are  completely 
unaware  of  the  incongruousness  of  the  combinations  which  are  thus  formed.     It 
has  been  well  remarked  that  "  nothing  surprises  us  in  dreams/'     All  probabili- 
ties of  *  time,  place,  and  circumstance'  are  violated ;  the  dead  pass  before  us  as 
if  alive  and  well ;  even  the  sages  of  antiquity  hold  personal  converse  with  us;  our 
friends  upon  the  antipodes  are  brought  upon  the  scene,  or  we  ourselves  are  con- 
veyed  thither,  without  the  least  perception  of  the  intervening  distance;    and 
occurrences,  such  as  in  our  waking  state  would  excite  the  strongest  emotions,  may 
be  contemplated  without  the  slightest  feeling  of  a  painful  or  pleasurable  nature. 
Facts  and  events  long  since  forgotten  in  the  waking  state,  and  remaining  only  as 
latent  impressions  on  the  Cerebrum  (§  642),  present  themselves  to  the  mind  of 
the  dreamer;  and  many  instances  have  occurred,  in  which  the  subsequent  reten- 
tion of  the  knowledge  thus  re-acquired  has  led  to  most  important  results.2     But 
one  of  the  most  remarkable  of  all  the  peculiarities  in  the  state  of  dreaming,  is 
the  rapidity  with  which  trains  of  thought  pass  through  the  mind ;  for  a  dream 
in  which  a  long  series  of  events  has  seemed  to  occur,  and  a  multitude  of  images 
has  been  successively  raised-up,  has  been  often  certainly  known  to  have  occupied 
only  a  few  minutes,  or  even  seconds,  although  whole  years  may  seem  to  the 
dreamer  to  have  elapsed.     There  would  not  appear,  in  truth,  to  be  any  limit  to 
the  amount  of  thought  which  may  thus  pass  through  the  mind  of  the  dreamer, 
in  an  interval  so  brief  as  to  be  scarcely  capable  of  measurement;  as  is  obvious 
from  the  fact,  that  a  dream  involving  a  long  succession  of  supposed  events,  has 
often  distinctly  originated  in  a  sound  which  has  also  awoke  the  sleeper,  so  that 
the  whole  must  have  passed  during  the  almost  inappreciable  period  of  transition 
between  the  previous  state  of  sleep  and  the  full  waking  consciousness.3     Hence 
it  has  been  argued  by  some,  that  all  our  dreams  really  take  place  in  the  momentary 
passage  between  the  states  of  sleeping  and  waking ;  but  such  an  idea  is  not  con- 
sistent with  the  fact,  that  the  course  of  a  dream  may  often  be  traced,  by  observ- 
ing the  successive  changes  of  expression  in  the  countenance  of  the  dreamer.     It 
seems,  however,  that  those  dreams  are  most  distinctly  remembered  in  the  waking 

1  Thus,  Condorcet  saw  in  his  dreams  the  final  steps  of  a  difficult  calculation  which  had 
puzzled  him  during  the  day :  and  Condillac  tells  us  that,  when  engaged  in  his  "  Cours 
d'Etude,  '  he  frequently  developed  and  finished  a  subject  in  his  dreams,  which  he  had 
broken-off  before  retiring  to  rest.  Coleridge  relates  of  himself,  that  his  fragment  "  Kubla 
Khan"  was  composed  during  sleep,  which  had  come  upon  him  whilst  reading  the  passage 
in  "  Purchas's  Pilgrimage"  on  which  the  poetical  description  was  founded,  and  was 
written-down  immediately  on  awaking,  "  the  images  rising  up  before  him  as  things,  with 
a  parallel  production  of  the  correspondent  expressions,  without  any  sensation  or  conscious- 
ness of  effort." 

a  See  a  number  of  such  cases  in  Dr.  Abercrombie's  "  Inquiries  concerning  the  Intellectual 
Powers." 

3  The  only  phase  of  the  waking  state,  in  which  any  such  intensely-rapid  succession  of 
thoughts  presents  itself,  is  that  which  is  now  well  attested  as  a  frequent  occurrence,  under 
circumstances  in  which  there  is  imminent  danger  of  death,  especially  by  drowning ;  the 
whole  previous  life  of  the  individual  seeming  to  be  presented  instantaneously  to  his  v'<>.w, 
with  its  every  important  incident  vividly  impressed  on  his  consciousness,  just  as  if  iU 
were  combined  in  a  picture,  the  whole  of  which  could  be  taken-in  at  a  glance. 


618  FUNCTIONS    OF   THE   CEKEBRO-SPINAL   NERVOUS   SYSTEM. 

state,  which  have  passed  through  the  mind  during  the  transitional  phase  just 
alluded-to;  whilst  those  which  occur  in  a  state  more  allied  to  Somnambulism, 
are  more  completely  isolated  from  the  ordinary  consciousness. — There  is  a  phase 
of  the  dreaming  state,  which  is  worthy  of  notice  as  marking  another  gradation 
between  this  and  the  vigilant  state;  that,  namely,  in  which  the  dreamer  has  a 
consciousness  that  he  is  dreaming,  being  aware  of  the  unreality  of  the  images 
which  present  themselves  before  his  mind.  He  may  even  make  a  voluntary  and 
successful  effort  to  prolong  them  if  agreeable,  or  to  dissipate  them  if  unpleaeing; 
thus  evincing  the  possession  of  a  certain  degree  of  that  directing  power,  the  entire 
want  of  which  is  the  characteristic  of  the  true  state  of  Dreaming. 

692.  But  the  sensibility  to  external  impressions  may  not  be  entirely  suspended 
in  Dreaming ;  and  it  is  curious  that  even  where  sensations  are  not  recognized  by 
the  mind  of  the  dreamer  as  proceeding  from  external  objects,  they  may  affect  the 
course  of  its  own  thoughts;  so  that  the  character  of  the  dreams  may  be  in  some 
degree  predetermined  by  such  an  arrangement  of  sensory  impressions  as  is  likely 
to  modify  them.  This  is  especially  the  case  in  regard  to  the  dreamy  state  in- 
duced by  certain  narcotics,  such  as  the  Hachisch  (a  preparation  of  Cannabis  In- 
died]  employed  for  this  purpose  in  the  East  (§  702)  ;  for  the  emotional  condition 
of  the  individual  under  its  influence,  is  entirely  under  the  control  of  external 
impressions;  so  that  those  who  give  themselves  up  to  the  intoxication  of  the 
fantasia,  take  care  to  withdraw  themselves  from  everything  which  could  give 
their  delirium  a  tendency  to  melancholy,  or  excite  in  them  anything  else  than 
feelings  of  pleasurable  enjoyment.1  Moreover,  there  are  certain  forms  of  ordi- 
nary Dreaming,  in  which  the  whole  succession  of  thought  and  feeling  (which  is 
made  manifest  by  the  words  occasionally  uttered,  or  by  the  play  of  countenance, 
or  by  the  more  active  movements  of  the  dreamer)  may  be  governed  by  external 
suggestion  ;  as,  for  example,  in  the  well-known  case  of  the  officer  who  amused 
his  friends  by  acting  his  dreams,  during  the  expedition  to  Louisburg,  the  course 
of  these  dreams  being  capable  of  direction  by  whispering  into  the  sleeper's  ear, 
especially  if  this  was  done  by  a  friend  with  whose  voice  he  was  familiar.2  Such 
forms  of  Dreaming  constitute  a  transition  to  the  state  of  Somnambulism. 

698.  Somnambulism. — The  phenomena  of  Somnambulism  are  so  various,  that 
it  is  difficult  to  give  any  general  definition  that  shall  include  the  whole ;  but  it 
is  a  condition  which  is  common  to  all  forms  of  this  state,  that  the  controlling 
power  of  the  Will  over  the  current  of  thought  is  entirely  suspended,  and.  that  all 
the  actions  are  directly  prompted  by  the  ideas  which  possess  the  mind ;  and  the 
differences  chiefly  arise  out  of  the  mode  in  which  the  succession  of  ideas  is 
directed,  this  being  in  some  cases  a  coherent  sequence  through  the  whole  of 
which  some  one  dominant  impression  may  be  traced,  whilst  in  other  instances  it 
is  more  or  less  completely  determinable  by  external  suggestions.  These  two 
forms  are  thus  parallel  to  the  states  of  spontaneous  Abstraction  and  artificial 
Reverie  (Electro-Biology)  respectively  (§§  671,  672);  but  differ  from  them  both 
in  this  essential  feature, — that  they  occur  in  a  state  of  consciousness  so  far  dis- 
tinct from  the  ordinary  waking  condition,  as  not  to  be  connected  with  it  by  the 
ordinary  link  of  Memory ;  and  that  although  the  course  of  thought  in  Somnam- 
bulism usually  manifests  the  directing  influence  of  previous  habits,  and  the  know- 
ledge of  persons  and  things  possessed  during  the  waking  state  may  be  readily 
brought  before  the  mind,  yet  nothing  which  occurs  during  the  state  of  Somnam- 
bulism is  ever  retraced  spontaneously,  or  can  be  brought-back  by  an  act  of  recol- 
lection. Impressions  upon  the  nervous  system,  however,  are  sometimes  left  by 

1  See  the  Author's  article,  'Sleep,'  in  the  "Cyclop,  of  Anat.  and  Phys.,"  vol.  iv. 
pp.  688-690;  and  Moreau  "Du  Hachisch  et  de  1' Alienation  Mentale,  Etudes  Psycholo- 
giques,"  p.  67. 

3  This  case  is  detailed  by  Dr.  Abercrombie  ("  Inquiries  concerning  the  Intellectual 
Towers,"  5th  Ed.,  p.  277,)  on  the  authority  of  Dr.  Gregory,  to  whom  it  was  related  by  a 
gentleman  who  witnessed  it.  A  case  of  a  very  similar  nature,  the  subject  of  which  was  a 
medical  student  at  Edinburgh,  is  related  iu  Suiellie's  "  Philosophy  of  Natural  History." 


OF    SLEEP    AND    SOMNAMBULISM.  619 

strong  emotional  excitement,  which  give-rise  to  subsequent  feelings  of  discom- 
fort, of  whose  origin  the  individual  is  entirely  unconscious.1 — In  the  first  of  the 
phases  just  referred-to,  a  train  of  reasoning  is  often  carried-out  with  remarkable 
clearness  and  correctness,  and  its  results  expressed  in  appropriate  language,  or 
otherwise  acted-on.  Thus,  a  mathematician  may  work-out  a  difficult  problem,  an 
orator  may  make  a  speech  appropriate  to  the  occasion  on  which  he  supposes  him- 
self to  be  called-up,  or  an  author  may  compose  and  commit  to  writing  poetry  or 
prose,  upon  the  subject  which  occupies  his  thoughts.  But  it  is  a  frequent  defect 
of  the  intellectual  operations  carried-on  in  this  condition,  that,  through  the  com- 
plete absorption  of  the  attention  by  one  set  of  considerations,  no  account  is  taken 
of  others  which  ought  to  modify  the  conclusion  ;  and  this,  although  it  may  be  pal- 
pably inconsistent  with  the  teachings  of  ordinary  experience,  is  not  felt  to  be  so, 
unless  the  latter  should  happen  to  present  themselves  unbidden  to  the  thoughts. 
694.  The  second  of  the  phases  above  mentioned,  which  is  especially  seen  in 
the  artificial  Somnambulism  induced  by  the  (so-called)  Mesmeric  process  (§  696), 
or  by  the  fixed  gaze  at  a  near  object  (as  practised  by  Mr.  Braid  under  the  name 
of  Hypnotism*),  is  essentially  the  same  as  that  of  the  '  biological '  condition,  save 
in  the  different  relation  which  they  respectively  bear  to  the  waking  state ;  for 
there  is  the  same  readiness  to  receive  new  impressions  through  the  senses  (the 
visual  sense,  however,  being  generally  in  abeyance),  and  the  same  want  of  persist- 
ence in  any  one  train  of  ideas,  the  direction  of  the  thoughts  being  entirely  deter- 
mined by  the  suggestions  which  are  introduced  from  without.  In  either  of  these 
extreme  forms  of  Somnambulism,  and  in  the  numerous  intermediate  places  which 
connect  the  two,  the  consciousness  seems  entirely  given-up  to  the  one  impression 
which  is  operating  upon  it  at  the  time;  so  that  whilst  the  attention  is  exclusively 
directed  upon  any  object,  whether  actually  perceived  through  the  senses,  or 
brought  suggestively  before  the  mind  by  previous  ideas,  nothing  else  is  felt. 
Thus  there  may  be  complete  insensibility  to  bodily  pain,  the  somnambulist's 
whole  attention  being  given  to  what  is  passing  in  his  mind  ;  yet  in  an  instant, 
by  directing  the  attention  to  the  organs  of  sense,  the  anaethesia  may  be  replaced 
by  ordinary  sensibility;  or,  by  the  fixation  of  the  attention  on  any  one  class  of 
hensations,  these -shall  be  perceived  with  most  extraordinary  acuteness,  whilst 
there  may  be  a  state  of  complete  insensibility  as  regards  the  rest. — Thus,  the 
Author  has  witnessed  a  case  in  which  such  an  exaltation  of  the  sense  of  Smell  was 
manifested,  that  the  subject  of  it  discovered  without  difficulty  the  owner  of  a  glove 
placed  in  his  hand,  in  an  assembly  of  fifty  or  sixty  persons ;  and  in  the  same 
case,  as  in  many  others,  there  was  a  similar  exaltation  of  the  sense  of  Tem- 
perature. The  exaltation  of  the  Muscular  Sense,  by  which  various  actions  that 
ordinarily  require  the  guidance  of  vision,  are  directed  independently  of  it,  is  a 
phenomenon  common  to  the  'mesmeric'  with  various  other  forms  of  artificial  as 
well  as  of  natural  Somnambulism.  The  Author  has  repeatedly  seen  Mr.  Braid's 
*  hypnotized '  subjects  write  with  the  most  perfect  regularity,  when  an  opaque 
screen  was  interposed  between  their  eyes  and  the  paper,  the  lines  being  equidis- 
tant and  parallel ;  and  it  is  not  uncommon  for  the  writer  to  carry  back  his  pen  or 
pencil  to  dot  an  i  or  cross  a  t,  or  make  some  other  correction  in  a  letter  or  word. 
>ir.  B.  had  one  patient  who  would  thus  go  back  and  correct  with  accuracy  the 
w.iting  on  a  whole  page  of  note-paper;  but  if  the  paper  was  moved  from  the 
position  it  had  previously  occupied  on  the  table,  all  the  corrections  were  on 
the  wrong  points  of  the  paper  as  regarded  the  actual  place  of  the  writing,  though 
on  the  riyht  points  as  regarded  its  previous  place ;  sometimes,  however,  ho  would 
take  a  fresh  departure,  by  feeling  for  the  upper  left-hand  corner  of  the  paper, 
and  all  his  corrections  were  then  made  in  their  right  positions,  notwithstanding 
the  displacement  of  the  paper. — So,  again,  when  the  attention  of  the  somnambu- 
list is  fixed  upon  a  certain  train  of  thought,  whatever  may  be  spoken  in  harmony 

1  See  a  very  curious  example  of  this  kind,  which  fell  under  the  Author's  own  observa- 
tion, narrated  in  the  Article  *  Sleep,'  in  the  "  Cyclop,  of  Anat.  and  Phys.,  vol.  iv.  p.  693 


620  FUNCTIONS   OF    THE  CEREBRO-SPINAL   NERVOUS    SYSTEM. 

with  this  is  heard  and  appreciated  ;  but  what  has  no  relation  to  it,  or  is  in  dis- 
cordance with  it,  is  entirely  disregarded. 

695.  It  is  among  the  most  curious  of  the  numerous  facts  which  Mr.  Braid's 
investigations  upon  artificial  Somnambulism  have  brought  to  light,  that  the  sug- 
gestions derived  from  the  '  muscular  sense '  have  a  peculiar  potency  in  determin- 
ing the  current  of  thought.     For  if  the  face,  body,  or  limbs  be  brought  into  an 
attitude  that  is  expressive  of  any  particular  emotion,  or  that  corresponds  with 
that  in  which  it  would  be  placed  for  the  performance  of  any  voluntary  action, 
the  corresponding  mental  state, — that  is,  either  an  Emotional  condition  affecting 
the  general  direction  of  the  thoughts,  or  the  Idea  of  a  particular  action, — is 
called-up  in  respondence  to  it.     Thus,  if  the  hand  be  placed  upon  the  vertex, 
the  Somnambulist  will  frequently,  of  his  own  accord,  draw  his  body  up  to  its 
fullest  height,  and  throw  his  head  slightly  back ;  his  countenance  then  assumes 
an  expression  of  the  most  lofty  pride,  and  the  whole  train  of  thought  is  obviously 
under  the  domination  of  this  feeling;  as  is  manifested  by  the  replies  which  the 
individual  makes  to  interrogatories,  and  by  the  tone  and  manner  in  which  these 
are  delivered.     Where  the  first  action  does  not  of  itself  call-forth  the  rest,  it  is 
sufficient  to  straighten  the  legs  and  spine,  and  to  throw  the  head  somewhat  back, 
to  arouse  the  emotion,  with  its  corresponding  manifestation,  in  its  full  intensity. 
If,  during  the  most  complete  domination  of  this  emotion,  the  head  be  bent  for- 
wards and  the  body  and  limbs  be  gently  flexed,  the  most  profound  humility  then 
takes  its  place.     So,  again,  if  the  angles  of  the  mouth  be  gently  separated  from 
one  another,  as  in  laughter,  a  hilarious  disposition  is  immediately  generated  ;  and 
this  may  be  made  to  give  place  to  moroseness,  by  drawing  the  eyebrows  towards 
each  other  and  downwards  upon  the  nose,  as  in  frowning.1     So,  again,  if  the  hand 
be  raised  above  the  head,  and  the  fingers  be  fixed  upon  the  palm,  the  idea  of 
climbing,  swinging,  or  pulling  at  a  rope  is  called-up  in  such  as  have  been  used 
to  such  kinds  of  exertion ;  if,  on  the  other  hand,  the  fingers  be  flexed  when  the 
arm  is  hanging-down  at  the  side,  the  idea  suggested  is  that  of  lifting  a  weight; 
and  if  the  same  flexure  be  made  when  the  arm  is  advanced  forwards  in  the  posi- 
tion of  striking  a  blow,  the  idea  of  fighting  is  at  once  aroused,  and  the  Somnam- 
bulist is  very  apt  to  put  it  into  immediate  execution.2 

696.  Mesmerism.  —  It  appears  to  the  Author  that  the  time  has  now  come, 
when  a  tolerably  definite  opinion  may  be  formed   regarding  a  large   number  of 
the  phenomena  commonly  included  under  the   term    'Mesmerism.'     Notwith- 
standing the  exposures  of  various  pretenders,  which  have  taken-place  from  time 
to  time,  there  remains  a  considerable  mass  of  phenomena  which  cannot  be  so 
readily  disposed-of,  and  which  can  put-forward  as  just,  a  title  to  the  attention  of 
the  scientific  Physiologist,  as  that  which  is  possessed  by  any  other  class  of  well- 
ascertained  facts.     Passing-over,  for  the  present,  the  inquiry  into  the  manner  in 
which  these  effects  may  be  induced,  the  Author  may  briefly  enumerate  the  prin- 
cipal phenomena  which  he  regards  as  having  been  veritably  presented  in  a  suffi- 
cient number  of  instances,  to  entitle  them  to  be  considered  as  genuine  and  regular 

1  The  Author  has  not  only  repeatedly  witnessed  all  these  effects,  as  produced  by  Mr. 
Braid  upon  '  hypnotized  '  subjects,  of  whom  several  had  never  been  previously  in  that  con- 
dition, and  had  no  idea  whatever  of  what  was  expected  from  them  ;  but  he  has  been  assured, 
by  a  most  intelligent  medical  friend,  who  has  paid  special  attention  to  the  psychologic*! 
part  of  this  inquiry,  that  having  subjected  himself  to  Mr.  Braid's  practice,  and  having 
been  only  partially  thrown  into  the  'hypnotic'  state  (in  fact,  'biologized')  he  distinctly 
remembers  everything  that  was  done,  and  can  retrace  the  uncontrollable  effect  upon  his 
emotional  state,  which  was  produced  by  this  management  of  his  muscular  apparatus. 

3  On  one  occasion  on  which  the  Author  witnessed  this  result,  a  violent  blow  was  struck, 
which  chanced  to  alight  upon  a  second  somnambulist  within  reach  ;  his  conobativeness 
being  thereby  excited,  the  two  closed,  and  began  to  belabour  one  another  with  such 
energy,  that  they  were  with  difficulty  separated.  Although  their  passions  were  at  this 
moment  so  strongly  excited,  that  even  when  separated  they  continued  to  utter  furious  de- 
nunciations against  each  other,  yet  a  little  discreet  manipulation  of  their  muscles  soon 
calmed  them  and  restored  them  to  perfect  good-humour. 


MESMERISM.  621 

manifestations  of  the  peculiar  bodily  and  mental  condition  under  discussion  :  — 
1.   A  state  of  complete  Coma  or  perfect  insensibility,  analogous  in  its  mode  of 
access  and  departure  to  that  which  is  known  as  the  l  Hysteric  Coma/  and  (like 
it)  usually  distinguishable  from  the  coma  of  Cerebral  oppression  by  a  constant 
twinkling  movement  of  the  eyelids.     In  this  condition,  severe  surgical  opera- 
tions may  be  performed,  without  any  consciousness  on  the  part  of  the  patient; 
and  it  is  not  unfrequently  found  that  the  state  of  torpor  extends  from  the  Cere- 
brum and  Sensory  Ganglia  to  the  Medulla  Oblongata,  so  that  the  respiratory 
movements  become  seriously  interfered-with,  and  a  state  of  partial  asphyxia  su- 
pervenes.—  2.  A  state  of  Somnambulism  or  Sleep-waking,  which  may  present 
all  the  varieties  of  the  natural  Somnambulism,  from  a  very  limited  awakening  of 
the  mental  powers,  to  the  state  of  complete  Double  Consciousness,  in  which  the 
individual  manifests  all  the  ordinary  powers  of  his  mind,  but  remembers  nothing 
of  what  has  passed  when  restored  to  his  natural  waking  state.     This  state  of 
Somnambulism,  in  the  form  which  it  commonly  takes,  is  characterized  by  the 
facility  with  which  the  thoughts  are  directed  into  any  channel  which  the  observer 
may  desire,  by  the  principle  of  (  suggestion  /  and  by  the  want  of  power  on  the 
part  of  the  Somnambulist,  to  apply  the  teachings  of  ordinary  experience  to  the  cor- 
rection of  the  erroneous  ideas  which  are  thus  made  to  occupy  the  mind.     In  these 
particulars,  this  condition  closely  corresponds  with  that  of  the  artificial  Somnam- 
bulism or  '  hypnotism '  of  Mr.  Braid  (§  694) ;  and   the  only  peculiarity  in  its 
phenomena  which  can  be  regarded  as  at  all  essential,  consists  in  the  special  rela- 
tion which  is  affirmed  to  exist  between  the  mesmerizer  and  his  '  subject.'     Now 
in  regard  to  the  existence  of  this  rapport,  it  is  specially  note-worthy,  that  it  was 
not  discovered  until  long  after  the  practice  of  Mesmerism  had  come  into  vogue, 
having  been  unknown  to  Mesmer  himself  and  his  immediate  disciples ;  and  that 
its  phenomena  have  only  acquired  constancy  and  fixity,  in  proportion  as  its  (sup- 
posed) laws  have  been  announced  and  received  as  established.     The  history  of 
Mesmerism,  candidly  and  philosophically  analysed,  affords  abundant  evidence  in 
proof  of  this  position  \  but  the  best  guarantee  of  its  truth  is  drawn  from  the 
results  obtained  from  the  numerous  Mesmerizers,  who  have  begun  to  experiment 
for  themselves  without  any  knowledge  of  what  they  were  to  expect,  and  who 
have  produced  a  great  variety  of  remarkable  phenomena,  without  having  ever 
discovered  this  rapport ;  and  yet  have  obtained  immediate  evidence  of  it,  when 
once  the  idea  has  been  put  into  their  own  minds,  and  thence  into  those  of  their 
'subjects.'     It  is  quite  easy  to  understand,  that  if  the  mind  of  the  ' subject'  be 
so  yielded-up  to  that  of  the  mesmerizer,  as  to  receive  and  act-upon  any  impres- 
sion which  the  latter  forces-upon  or  even  suggests-to  it,  the  notion  of  this  pecu- 
liar relation  is  as  easily  communicable  as  any  other,  and  may  exert  a  complete 
domination  over  the  '  subject/   through  the  whole  of  the  sleep-waking  state. 
Thus  the  commands  or  suggestions  of  the  mesmerizer  meet  with  a  response  which 
those  of  no  other  individual  may  produce ;  in  fact,  the  latter  usually  seem  to  be 
unheard  by  the  somnambule,  simply  because  they  are  not  related  to  the  dominant 
impression,  —  a  phenomenon  of  which  the  experience  of  natural  somnambulism 
is  continually  presenting  examples  (§  694).     Further,  it  being  a  fact  that  indi- 
viduals of  what  may  be  termed  the  susceptible  constitution,  have  brought  them- 
selves, by  the  habit  of  obedience,  into  complete  subjection  to  the  expressed  or 
understood  will  of  some  other  parry,  even  in  the  waking  state,  without  any  mes- 
meric influence  whatever,  it  is  not  at  all  difficult  to  understand  how  such  a  habit 
of  attending  to  the  operator,  and  to  him  alone,  should  be  peculiarly  developed  in 
the  state  of  Somnambulism,  in  which  the  mind  seems  to  have  lost  its  self-acting 
power,  and  to  be  the  passive  recipient  of  external  impressions.     And  the  same 
explanation  applies  to  the  other  phenomena  of  this  rapport ;  such  as  its  establish- 
ment with  any  bystander,  by  his  joining  hands  with  the  mesmerizer  and  the  som- 
nambulej  for,  as  already  shown  (§  694),  it  is  quite  sufficient  that  the  sornnambule 
should  be  previously  possessed  with  the   idea  that  this  new  voice  will  thus  be 


622  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

audible  to  her,  and  that  she  must  obey  its  behests,  for  it  to  produce  all  the  same 
effects  upon  her  as  that  of  the  mesmerizer  had  previously  done.  In  all  the  suc- 
cessful experiments  of  this  kind  which  the  Author  has  seen,  this  previous  idea 
was  entertained,  both  by  mesmerizer  and  somnambule  ;  but  in  by  far  the  larger 
proportion  of  cases  which  have  fallen  under  his  notice,  and  especially  when  the 
subjects  of  them  were  not  habitudes  of  the  mesmeric  stances,  the  phenomena  of 
this  class  could  not  be  made  to  show  themselves,  the  consciousness  of  the  som- 
nambule not  being  limited  to  the  mesmerizer  or  to  those  en  rapport  with  him, 
but  being  equally  extended  to  all  around  her.  —  3.  A  frequent  phenomenon  of 
this  condition,  and  one  which  has  its  parallel  in  natural  Somnambulism  (§  694), 
is  a  remarkable  Exaltation  of  one  or  more  of  the  Senses,  so  that  the  individual 
becomes  susceptible  of  influences  which,  in  his  natural  condition,  would  not  be 
in  the  least  perceived.  To  this  exaltation  may  fairly  be  attributed  a  great 
number  of  the  phenomena,  which  have  been  supposed  to  indicate  a  peculiar  and 
mysterious  influence  exerted  by  the  Mesmerizer  over  his  'subject;'  since  the 
latter  will  be  far  more  receptive  of  'suggesting'  impressions,  than  a.n  ordinary 
bystander  would  suppose  possible.  And  it  is  to  be  borne  in  mind  that  the  con- 
centration of  the  attention  upon  these  may  often  give  them  a  far  greater  signi- 
ficance to  the  individual,  than  they  possess  for  others;  this,  it  seems  likely,  is 
especially  the  case  in  regard  to  tones  of  voice,  emphasis  of  manner,  &c.,  when 
questions  are  propounded.  — 4.  The  Muscular  apparatus  may  also  be  excited  to 
action  in  unusual  modes,  and  with  unusual  energy.  Notwithstanding  the  fallacy 
of  many  of  the  cases  of  Cataleptic  rigidity  which  have  been  publicly  exhibited, 
the  Author  is  satisfied,  from  investigations  privately  made,  of  the  possibility  of 
artificially  inducing  this  condition.  A  slight  irritation  of  the  muscles  themselves, 
or  of  the  skin  which  covers  them,  as  by  drawing  the  points  of  the  fingers  over 
them,  or  even  wafting  currents  of  air  over  the  surface,  —  is  sufficient  to  excite 
the  tonic  muscular  contraction,  which  may  continue  in  sufficient  force  to  suspend 
a  considerable  weight,  for  a  longer  period  than  could  be  kept  up  by  any  conceiv- 
able effort  of  voluntary  power.  But  these  are  phenomena  which  are  quite  as 
well  displayed  in  artificial  Somnambulism  induced  in  other  ways,  as  they  are  in 
the  '  mesmeric '  state  :  and  do  not  afford,  therefore,  any  more  than  the  preceding, 
the  slightest  indication  of  the  speciality  of  the  latter,  or  the  least  proof  of  any 
extraneous  influence  exerted  over  the  '  subject/ — 5.  A^arious  effects,  it  is  asserted, 
may  be  produced  upon  the  Organic  Functions  by  'Mesmeric'  influence;  and  it 
is  on  account  of  this  agency,  that  it  claims  to  be  admitted  as  a  directly-curative 
agent.  It  will  be  hereafter  shown,  however,  that  effects  of  a  precisely  similar 
kind  may  be  produced  in  other  forms  of  Artificial  Somnambulism,  by  simply 
fixing  the  attention  on  the  part ;  and  that  the  same  may  be  done,  even  in  the 
ordinary  waking  state,  in  certain  subjects  who  can  be  worked-up  to  the  requisite 
pitch  of  confident  expectation.  (See  §  837.) ! 

1  The  above  are  the  principal  phenomena  of  the  *  Mesmeric '  state,  in  regard  to  which 
the  Author  feels  his  mind  made-up,  He  does  not  see  why  any  discredit  should  be 
attached  to  them,  since  they  correspond  in  all  essential  particulars  with  those  of  states, 
which  naturally  or  spontaneously  occur  in  many  individuals,  and  which  he  has  had  oppor- 
tunities of  personally  observing,  in  cases  in  which  the  well-known  characters  of  the  parties 
placed  them  above  suspicion.  When  the  facility  with  which  the  mind  of  the  Somnambulist 
is  played-on  by  suggestions  (conveyed  either  in  language,  or  through  other  sensations 
which  excite  associated  ideas),  and  the  absence  of  the  corrective  power  ordinarily  supplied 
by  past  experience,  are  duly  kept  in  view,  many  of  the  supposed  '  higher  phenomena '  of 
Mesmerism  may  be  accounted-for,  without  regarding  the  patient  on  the  one  hand  as  pos- 
sessed of  extraordinary  powers  of  divination,  or  on  the  other  as  practising  a  deception. 
Thus,  bearing  in  mind  that  Somnambulism  is  an  acted  dream,  the  course  of  which  is 
governed  by  external  impressions,  it  is  easy  to  understand  how  the  subject  of  it  may  be 
directed  by  '  leading  questions '  to  enter  buildings  which  he  has  never  seen,  and  to  describe 
scenes  which  he  has  never  witnessed,  without  any  intentional  deceit.  The  love  of  the 
marvellous  so  strongly  possessed  by  many  of  the  witnesses  of  such  exhibitions,  prompts 
them  to  grasp-at  and  to  exaggerate  the  coincidences  in  all  such  performances,  and  to 
neglect  the  failures:  and  hence  reports  are  given  to  the  public,  which,  when  the  real  J>*uth 


GENERAL    RECAPITULATION.  623 

8.  General  Recapitulation,  and  Pathological  Applications. 

In  summing-up  the  views  which  have  been  propounded  in  this  Chapter  with 
regard  to  the  normal  functions  of  the  Nervous  System,  and  in  applying  these  to 
the  elucidation  of  its  principal  modes  of  abnormal  activity,  it  will  be  advan- 
tageous to  follow  the  reverse  order  to  that  which  has  been  previously  adopted, 
and  to  proceed  from  above  downwards,  instead  of  from  below  upwards. 

697.  The  entire  Nervous  System,  like  other  organs  of  the  body,  possesses 
vital  endowments  peculiar  to  itself,  in  virtue  of  which  it  tends  to  respond  in  a 

of  them  is  known,  prove  to  have  been  the  results  of  a  series  of  guesses,  the  correctness  of 
•which  is  in  direct  relation  to  the  amount  of  guidance  afforded  by  the  questions  themselves. 
In  like  manner,  the  manifestations  of  the  excitement  of  the  '  phrenological  organs '  seem 
to  depend  upon  the  conveyance  of  a  suggestion  to  the  patient,  either  through  his  know- 
ledge of  their  supposed  seat,  or  through  the  anticipations  expressed  by  the  by-standers. 
Many  instances  are  recorded,  in  which  the  intention  has  been  stated  of  exciting  one  organ, 
whilst  the  finger  has  been  placed-upon  or  pointed-at  another ;  and  the  resulting  manifesta- 
tion has  always  been  that  which  would  flow  from  the  former.  It  does  not  hence  follow 
that  intentional  deception  is  being  practised  by  the  Somnambulist ;  since  the  condition  of 
mind  already  referred-to,  causes  it  to  respond  to  the  suggestion  which  is  most  strongly 
conveyed  to  it. 

In  regard  to  the  alleged  powers  which  are  said  to  be  possessed  by  many  Somnambulists, 
of  reading  with  the  eyes  completely  covered,  or  of  discerning  words  enclosed  in  opaque 
boxes,  or  of  giving  an  account  of  what  is  taking-place  at  a  distance,  all  coming  under  the 
general  term  Clairvoyance,  the  Author  need  only  here  express  his  conviction  that  no  case 
of  this  description  has  ever  stood  the  test  of  a  searching  investigation. 

With  respect  to  the  modes  in  which  the  '  Mesmeric '  Somnambulism  is  induced,  it 
appears  to  him  that  they  are  all  referable  to  those  states  of  monotony  of  sensory  impres- 
sions, and  of  expectation,  to  which  reference  has  been  already  made,  as  among  the  most 
potent  of  the  predisposing  causes  of  conditions  allied  to  Sleep  ($$  682,  685).  It  is  asserted 
by  Mesmerizers,  that  they  can  induce  the  '  Mesmeric '  state  from  a  distance,  without  the 
least  consciousness  on  the  part  of  their  '  subjects '  that  any  influence  is  being  exerted  on 
them, — an  assertion,  which,  if  true,  would  go-far  to  establish  the  existence  of  a  force 
altogether  sui  generis,  capable  of  being  transmitted  from  one  individual  to  another.  Here, 
however,  as  in  regard  to  the  'higher  phenomena'  last  adverted-to,  the  Author  feels  com- 
pelled to  state  that  no  evidence  of  an  affirmative  kind  has  yet  been  adduced,  which  can  be 
in  the  least  degree  satisfactory  to  a  scientific  enquirer,  who  duly  appreciates  all  the  sources 
of  fallacy  to  which  these  occurrences  are  open.  Among  these,  the  state  of  expectation  on 
the  part  of  the  '  subject '  is  the  most  important ;  since  this  has  been  shown,  by  repeated 
experiments,  to  be  of  itself  quite  sufficient  to  induce  the  state,  when  the  '  subject '  hag 
been  led  to  entertain  it ;  whilst,  if  it  be  altogether  wanting,  the  most  powerful  Mesmeric 
influence,  so  far  as  the  Author's  personal  knowledge  extends  (and  on  this  subject,  he  must 
be  excused  for  trusting  rather  to  the  results  of  his  own  investigations,  than  to  the  state- 
ments of  other  individuals,  however  trustworthy  on  ordinary  matters),  has  always  failed. 
A  very  striking  instance  of  this  kind  is  contained  in  the  "Brit,  and  For.  Med.  Rev.," 
vol.  xix.  p.  478,  in  an  Article  to  which  the  Author  may  refer  as  on  the  whole  expressing 
(although  not  written  by  himself)  his  own  opinions  on  this  curious  and  interesting  subject, 
strengthened  as  these  are  by  much  subsequent  inquiry  into  the  phenomena  of  '  Hypnotism ' 
and  '  Electro-Biology,'  the  attentive  and  scientific  study  of  which  will  tend,  he  feels 
assured,  to  eliminate  the  true  from  the  false  in  Mesmerism,  more  effectually  than  any 
other  method  of  procedure.  Much  has  been  done  by  the  enquiries  of  Mr.  Braid  of  Man- 
chester, who  discovered  the  'hypnotic'  mode  of  inducing  artificial  Somnambulism,  and 
who  has  carefully  studied  the  phenomena  of  the  hypnotic  state ;  and  the  Author  feels  it 
due  to  that  gentleman  further  to  mention,  that  very  soon  after  the  publication  of  the  first 
edition  of  Baron  Reichenbach's  researches  on  Odyle,  Mr.  Braid  discovered  their  true 
explanation,  and  exhibited  to  the  Author  many  of  the  'odylic'  phenomena,  as  the  results 
of  suggestion  in  certain  individuals,  whom  he  had  discovered  to  have  the  power  of  volun- 
tarily inducing  a  state  of  Abstraction  or  artificial  reverie,  closely  corresponding  to  what  is 
QOW  termed  the  Electro-Biological  condition. 

On  the  whole  subject  of  Sleep  and  its  allied  states,  as  well  as  on  that  of  Cerebral 
Physiology  generally,  the  Author  would  strongly  recommend  his  readers  to  study  Sir  H. 
Holland's  "  Chapters  on  Mental  Physiology;"  in  which  they  will  find  a  most  valuable  and 
suggestive  collection  of  facts  and  doctrines,  based  upon  an  extended  practical  experience, 
and  brought  to  bear  particularly  upon  the  more  difficult  and  recondite  portions  of  the 
inquiry.  A  fuller  analysis  of  the  phenomena  of  Somnambulism  (natural  and  artificial  (, 
Mesmerism,  and  other  allied  states,  will  be  found  in  the  "Quarterly  Review,"  Sept.,  185>> 


624  FUNCTIONS   OF  THE    CEREBRO-SPINAL  NERVOUS   SYSTEM. 

determinate  manner  to  impressions  made  upon  it ;  the  properties  of  its  several 
parts  being  distinguished  by  the  modus  operandi  of  impressions  upon  each  re- 
spectively. In  so  far,  then,  as  any  part  of  the  Nervous  System  merely  reacts 
upon  impressions  which  are  made  upon  it,  we  must  regard  its  operations  as 
automatic  ;  and  this  as  much  when  they  give  rise  to  Psychical  changes,  as  when 
they  manifest  themselves  in  evoking  Muscular  movements,  or  in  modifying  the 
processes  of  Nutrition  and  Secretion. — But  the  automatic  actions  of  most  parts 
'vf  the  Nervous  System  are  subject,  more  or  less  completely,  to  the  domination 
*>f  the  Will,  a  power  which  is  purely  Psychical,  and  of  which  we  know  nothing 
*mt  what  we  learn  from  our  own  direct  consciousness  of  its  exercise.  The  power 
of  the  Will  is  the  greatest  over  the  automatic  actions  of  the  highest  portions  of 
<he  Nervous  Centres,  which  are  concerned  in  psychical  changes ;  whilst  it  has 
the  least  influence  over  the  automatic  actions  of  those  lower  centres,  which  min- 
ister solely  to  the  functions  of  the  bodily  organism. 

698.  Normal  Modes  of  Cerebral  Activity. — The  Cerebrum  is  the  material 
organ,  through  whose  instrumentality  of  all  the  processes  of  Thought  are  car- 
ried-on.  These  processes  are  first  called  into  activity  by  impressions  conveyed  to 
the  vesicular  matter  of  the  Cerebral  surface,  by  ascending  nerve-fibres  which 
proceed  to  it  from  the  Sensory  Ganglia ;  and  the  influence  of  that  activity  is  re- 
transmitted to  the  Sensory  Ganglia,  by  a  converse  set  of  descending  fibres.1  There 
is  much  reason  to  consider  that,  until  such  re-transmission  has  taken  place,  the 
consciousness  is  not  so  affected  by  Cerebral  changes,  as  to  give  to  the  results  of 
these  changes  a  psychical  character ;  for  the  central  Sensorium  appears  to  stand 
in  precisely  the  same  anatomical  and  physiological  relation  to  the  vesicular  mat- 
ter of  the  Cerebral  surface,  that  it  does  to  the  vesicular  matter  of  the  Retina  or 
other  peripheral  expansions  of  the  Sensory  nerves ;  and  there  is  strong  analogical 
ground  for  the  belief,  that  the  process  by  which  the  Mind  is  rendered  cognizant 
of  changes  in  the  Cerebrum,  is  performed  by  the  same  instrumentality  as  that 
by  which  it  is  made  acquainted  with  impressions  on  the  Organs  of  Sense.  And 
this  view  is  confirmed  by  the  fact,  that  automatic  changes  may  take  place  in  the 
Cerebrum  without  any  consciousness  on  our  own  parts ;  the  results  of  which 
changes,  when  we  at  last  become  conscious  of  them,  correspond  with  those  that 
we  ordinarily  attain  by  processes  whose  successive  steps  excite  as  many  successive 
states  of  consciousness. — These  Cerebral  changes,  then,  acting  downwards  upon 
the  Sensorium,  give  rise  to  those  affections  of  our  consciousness,  which  we  desig- 
nate as  Mental  Processes.  These  processes, — called  into  activity  by  Sensorial 
impressions, — ranging  from  the  simplest  act  of  Ideation  to  the  highest  operations 
of  Intellectual  power, — consisting  also  in  the  play  of  Fancy  and  Imagination, 
and  including  an  essential  part  of  those  active  states  known  as  Passions,  Emo- 
tions, Moral  Feelings,  Sentiments,  &c., — must  be  regarded  as  essentially  auto- 
matic in  their  nature,  and  as  the  manifestations  of  the  '  reflex '  activity  of  the 
Cerebrum ;  since  we  have  abundant  evidence  that  they  can  take-place  without 
any  self-direction  on  the  part  of  the  individual,  who,  whilst  his  Will  is  in  abey- 
ance, is  in  the  condition  of  an  animal  entirely  governed  by  Instinct.  There  is, 
however,  far  less  of  uniformity  in  these  '  reflex  actions '  of  the  Cerebrum,  than 
we  observe  in  those  reflex  actions  of  other  parts  of  the  Nervous  System,  which 
give-rise  to  the  movements  ordinarily  designated  as  '  instinctive ;'  this  diversity 
seems  partly  attributable  to  differences  in  the  original  constitution  of  different 
individuals;  but  it  is  certainly  due  in  great  part  to  differences  in  the  acquired 
constitution  of  the  organ,  arising  out  of  the  mode  in  which  it  has  been  habitually 

1  The  structural  distinctness  of  these  two  sets  of  fibres  must  be  admitted  to  be  hypo- 
thetical ;  and  it  is  improbable  that  any  anatomical  evidence  can  ever  be  attained,  by  which 
the  hypothesis  may  be  established.  But  all  the  analogy  of  the  afferent  and  efferent  fibres 
throughout  the  body,  is  opposed  to  the  idea  that  the  same  fibres  can  serve  both  purposes. 
Whatever  may  be  thought  of  their  structural  distinctness,  however,  there  can  be  no  reason- 
able doubt  of  the  transmission  of  nerve-force  in  the  two  directions  above  indicated. 


ABNORMAL    MODES     OF    CEREBRAL    ACTIVITY.         625 

exercised, — this  being  dependent,  on  the  one  hand,  on  the  circumstances  in 
which  the  individual  has  been  placed,  and,  on  the  other,  on  the  use  he  has  made 
of  his  Will. 

699.  When  the  power  of  the  Will  has  been  duly  cultivated,  it  acquires  so 
complete  a  domination  over  the   'automatic'  actions  of  the  Cerebrum,  that  it 
can  regulate  the  course  of  Thought  and  the  degree   of  Emotional  excitement ; 
intensifying  some  of  these  actions,  and  repressing  others,  by  determinate  efforts 
directed  with  that  special  purpose.     Its  power  is  so  far  limited,  however, — that 
it  can  only  select  from  the  objects  which  spontaneously  present  themselves  to  the 
consciousness,  those  which  it  desires  to  retain  and  employ;  and  has  no   direct 
power  of  bringing  before  the  mind  any  object  not  actually  present  to  it.      Hence 
it  is,  that,  whilst  we  have  an  almost  unlimited  power  of  turning  to  the  best 
account  the  endowments  we  possess,  by  strengthening  our  Intellectual  powers, 
expanding  our  higher  Emotional  tendencies,  and  bringing  the  lower  Propensities 
under  wholesome  restraint,  we  cannot,  by  any  effort  of  the  Will,  introduce  new 
elements  into  our  psychical  nature. 

700.  The  power  of  the  Cerebrum  to  call-forth  Muscular  movements,  is  entirely 
exerted  through  the  intermediation  of  the  Cranio-Spinal  Axis  upon  which  it  is 
superimposed  ;  no  motor  fibres  directly  issuing  from  the  Cerebrum  itself.     These 
movements,  when  directly  determined  by  the  Will,  may  be  designated  as  Voli- 
tional; when  they  are  involuntarily  excited  by  states  of  passion,  feeling,  &c.,  of 
which  they  are  the  external  expressions,  they  are  distinguished  as  Emotional; 
and  when  they  are  prompted,  in  the  absence  of  any  volitional  exertion,  by  the 
Idea  which  may  for  the  time  engross  the  consciousness,  they  may  be  termed 
Ideational.     In  each  case,  the  nerve-force  transmitted  downwards  from  the  Cere- 
brum appears  to  produce  the  very  same  state  of  activity  in  the  Sensori-motor 
apparatus,  as  that  which  may  be  directly  excited  in  it  by  impressions  transmitted 
from   the  Organs  of  Sense ;  and  thus  the  same  instrumentality  serves  for  all 
classes  of  movements,  Voluntary  and  Involuntary,  the  difference  in  their  cha- 
racter being  solely  referable  to  the  diversity  of  their  primal  source. 

701.  Abnormal  Modes  of  Cerebral  Activity. — The  Cerebrum  being  the  instru- 
ment of  all  psychical  activity,  we  must  regard  its  action  as  disordered  in  every 
state  in  which  that  activity  is  perverted.     The  first  degree  of  departure  from  the 
normal  state,  is  usually  shown  in  the  want  of  Volitional  control  over  the  sequence 
of  thought;  and  this  may  exist  merely  to  the  extent  of  giving  the  reflex  power  of 
the  organ  too  great  a  predominance,  so  that  trains  of  ideas  and  states  of  feeling 
succeed  each  other  automatically,  and  all  the  actions  of  the  individual  are  simply 
the  expressions  of  these.     Such  is  the  mental  state  which  exists  in  Reverie  and 
in   Somnambulism,  natural  or  induced;   the  principal  varieties  in  these  states 
being  traceable  to  the  relative  degree  of  influence  of  ideas  already  fixed  in  the 
mind,  and  of  external  suggestions,  in  determining  the  course  of  thought.     It  is 
to  be  remarked,  however,  in  regard  to  these  conditions,  that  they  are  generally 
characterized  by  a  somewhat  inactive  state  of  the  Cerebrum,  so  that  the  changes 
in  the  state  of  consciousness  are  not  rapid,  though  such  as  do  occur  are  coherent.1 
In  Dreaming,  Delirium,  and  the  artificial  delirium  of  Intoxication,  on  the  other 
hand,  with  a  like  absence  of  the  directing  and  restraining  power  of  the  Will, 
there  is  a  greater  and  more  irregular  activity  in  the  Cerebral  operations;  the  ideas 
presenting  themselves  in  far  more  rapid  succession,  and  possessing  a  less  perfect 
mutual  coherence. 

1  In  most  forms  of  induced  Somnambulism,  it  appears  as  if  the  mental  activity  is  omj 
sustained  by  external  prompting,  all  spontaneous  activity  being  suspended ;  for  tbe  '  sub- 
ject' continually  relapses  into  a  state  of  unconsciousness,  and  does  not  pass  from  one  topic 
to  another,  unless  induced  to  do  so  by  'leading  questions.'  In  some  cases  of  this  kind, 
however,  as  well  as  in  all  those  forms  of  natural  Somnambulism  in  which  the  individual 
acts  on  the  spontaneous  promptings  of  his  own  thoughts,  the  mental  state  is  one  of  conti- 
nuous activity;  but  it  is  obvious  that  its  operations  are  slow,  and  are  very  limited  in  their 
nature. 

40 


626  FUNCTIONS    OF   THE   CEREBRO-SPINAL   NERVOT7S    SYSTEM. 

702.  Very  nearly  allied  to  Dreaming  and   Somnambulism,  are  the  states  of 
Delirium  and  of  Mania,  which  graduate  almost  imperceptibly  one  into  the  oth  jr  ; 
being  chiefly  distinguished  by  the  degree  and  kind  of  excitement  which  they 
respectively  exhibit,  and  by  the  nature  of  the  bodily  states  with  which  they  are 
connected.     The  loss  of  Voluntary  control  over  the  current  of  thought,  is   the 
primary  element  of  both  these  conditions;  and  the  gradual  weakening  of  this 
may  be   frequently  traced,  when  the  transition  from  the  normal  state  is  not  so 
rapid  as  to  prevent  its  various  steps  from  being  watched.     The  artificial  delirium 
produced  by  Intoxicating  agents,  affords  peculiar  facilities  for  this  kind  of  obser- 
vation; and  among  these  agents,  there  is  none  whose  operation  is  so  interesting 
in    this  respect  as  Hachisch.     The  first  effect  of  a  dose   of  this  substance,  as 
described  by  M.  Moreau  (Op.  cit.),  is  commonly  to  produce  a  moderate  exhilara- 
tion of  the  feelings,  and  an  unusual  activity  of  the  intellectual  powers ;  but  this 
activity  gradually  frees  itself  from  the  control  of  the  Will.     The  individual  feels 
himself  incapable  of  fixing  his  attention  upon  any  subject;  his  thoughts  being 
continually  drawn-off  by  a  succession  of  ideas  which  force  themselves  (as  it  were) 
into  his  mind,  without  his  being  in  the  least  able  to  trace  their  origin.     These 
speedily  occupy  his  attention,  and  present  themselves  in  strange  combinations,  so 
as  to  produce  the  most  fantastic  and  impossible  creations.     By  a  strong  effort  of 
volition,  however,  the  original  thread  of  the  ideas  may  be   recovered,  and  the 
interlopers  driven  away.     These  *  lucid  intervals  '  successively  become  of  shorter 
and  shorter  duration,  and  can  be  less  frequently  procured  by  a  voluntary  effort; 
for  the  internal  tempest  becomes  more  and  more  violent,  the  torrent  of  (apparently) 
disconnected  ideas  increases  in  vehemence,  so  as  completely  to  arrest  the  atten- 
tion, and  the  mind  is  at  last  entirely  given-up  to  it,  and  is  at  the  same  time  with- 
drawn from  the  perceptive  consciousness  of  external  things,  although  as  already 
pointed-out '(§  692),  it  is  by  no  means  removed  from  the  influence  of  sensory 
impressions.     The  succession  of  ideas  has  at  first  less  of  incoherence  than  in  ordi- 
nary dreaming,  the  ideal  events  not  departing  so  widely  from  possible  realities; 
and  the  disorder  of  the  mind  is  primarily  manifested  in  errors  of  perception,  in 
false  convictions,  or  in  the  predominance  of  one  or  more  extravagant  notions. 
These  false  ideas  are  generally  not  altogether  of  an  imaginary  character,  but  are 
originally  called  into  existence  by  external  impressions,  these  being  erroneously 
interpreted  through  the  disordered  action   of  the  perceptive  faculty ;   thus,  for 
example,  among  the  most  common  perversions  are  those  relating  to  time  and 
space,  minutes  seeming  hours,  hours  being  prolonged  into  years,  and  all  idea  of 
time  being  at  last  obliterated,  so  that  past  and  present  are  confounded  together  as 
in  ordinary  dreaming;  whilst  in  like  manner,  streets  may  appear  of  an  intermi- 
nable length,  the  people  at  the  other  end  seeming  to  be  at  a  vast  distance;  for 
the  mind  has  a  tendency  to  exaggerate  every  impression  made  upon  the  conscious- 
ness, especially  those  which  affect  the  emotional  state.     The  effect  of  a  full  dose, 
however,  is  at  last  to  produce  the  complete  withdrawal  of  the  mind  from  the  con- 
templation of  external  things,  and  entirely  to  suspend  the  action  of  the  Will  over 
the  current  of  thought ;  and  the  condition  then  comes  to  be  nearly  the  same  as 
that  of  ordinary  Dreaming,  the  chief  difference  consisting  in  the  readiness  with 
which  the  emotions  may  be  excited  in  those  who  are  under  the  influence  of  the 
Hachisch,  and  in  the  degree  in  which   their  course  of  thought  is  amenable  to 
external  influences. 

703.  The  following  concise  and  faithful  description  of  the  ordinary  Delirium 
of  disease,  will  show  how  completely  it  corresponds  in  all  its  essential  characters 
with  that  which  is  induced  by  the  introduction  of  intoxicating  agents  into  the 
blood.     "  In  its  highest  degree  it  is  a  complete  disturbance  of  the  intellectual 
actions;  the  thoughts  are  not  inactive,  but  rather  far  more  active  than  in  health; 
they  are  uncontrolled,  and  wander  from  one  subject  to  another  with  extraordinary 
rapidity;  or,  taking  up  one  single  subject,  they  twist  and  turn  it  in  every  way 
and  shape,  with  endless  and  innumerable  repetitions.     The  thinking  faculty  seems 


ABNORMAL    MODES    OF    CEREBRAL    ACTIVITY.         627 

to  have  escaped  from  all  control  and  restraint,  and  thought  after  thought  is 
engendered  without  any  power  of  the  patient  to  direct  and  regulate  them.  Some- 
times they  succeed  each  other  with  such  velocity,  that  all  power  of  perception  is 
destroyed,  and  the  mind,  wholly  engrossed  with  this  rapid  development  of 
thoughts,  is  unable  to  perceive  impressions  made  upon  the  senses;  the  patient 
goes-on  unceasingly  raving,  apparently  unconscious  of  what  is  taking  place  around 
him;  or  it  may  be,  that  his  senses  have  become  more  acute,  and  that  every  word 
from  a  bystander,  or  every  object  presented  to  his  vision,  will  become  the  nucleus 
of  a  new  train  of  thought;  and,  moreover,  such  may  be  the  exaltation  of  his  sen- 
sual perception,  that  subjective  phenomena  will  arise  in  connection  with  each 
sense,  and  the  patient  fancies  he  hears  voices  or  other  sounds,  whilst  ocular  spec- 
tra in  various  forms  and  shapes  appear  before  his  eyes  and  excite  further  rhapso- 
dies of  thought."1  It  must  be  remarked  that  there  is  usually  a  greater  disorder 
of  the  perceptive  faculty  in  Delirium,  than  in  ordinary  Dreaming;  for  in  the  for- 
mer condition,  the  erroneous  images  are  more  vividly  conceived-of  as  having  an 
existence  external  to  the  mind,  than  they  are  in  the  latter;  the  illusory  visual  and 
auditory  perceptions  having  all  the  force  of  reality,  and  often  appearing  to  be  the 
original  sources  of  ideas,  instead  of  (as  seems  to  be  rather  the  case  in  dreaming) 
their  products.2  This  peculiarity  probably  depends  upon  a  primary  affection  of 
the  Sensorial  centres  by  the  morbid  agent  (§  716). 

704.  The  more  active  forms  of  Delirium  pass  by  almost  imperceptible  grada- 
tions into  the  state  of  Mania,  which  is  usually  characterized  by  the  combination, 
of  complete  derangement  of  the  intellectual  powers,  with  passionate  excitement 
upon  every  point  which  in  the  least  degree  affects  the  feelings.  There  is,  how- 
ever, a  considerable  amount  of  variety  in  the  phases  of  Mania,  depending  upon 
differences  in  the  relative  degree  of  intellectual  and  of  emotional  disturbance. 
For  there  may  be  such  a  derangement  of  the  former,  as  gives-rise  to  complete 
incoherence  in  the  succession  of  ideas,  so  that  the  reasoning  power  is  altogether 
suspended ;  and  yet  there  may  be  at  the  same  time  an  entire  absence  of  emotional 
excitement,  so  that  the  condition  of  the  mind  is  closely  allied  to  that  of  dream- 
ing or  of  rambling  delirium.  On  the  other  hand,  the  intellectual  powers  may 
be  themselves  but  little  disturbed,  the  trains  of  thought  being  coherent,  and  the 
reasoning  processes  correctly  performed;  but  there  may  be  such  a  state  of 

1  See  Dr.  Todd's  '  Lumleian  Lectures,  on  the  Pathology  and  Treatment  of  Delirium  and 
Coma,'  in  the. "  Medical  Gazette,"  1850,  vol.  xlv.  p.  703. — A  circumstance  was  mentioned 
to  the  Author,  whilst  he  was  a  student  at  Edinburgh,  which  remarkably  illustrates  the 
influence  of  suggestions  derived  from  external  sources,  in  determining  the  current  of 
thought.     During  an  epidemic  of  Fever  which  had,  occurred  some  time  previously,  and  in 
which  an  active  delirium  had  been  a  common  symptom,  it  was  observed  that  many  of  the 
patients  of  one  particular  physician  were  possessed  by  a  strong  tendency  to  throw  them- 
selves out  of  the  window,  whilst  no  such  tendency  presented  itself  in  unusual  frequency 
in  the  practice  of  others.     The  Author's  informant,  himself  a  distinguished  Professor  in 
the  University,  explained  this  tendency  by  what  had  occurred  within  his  own  knowledge, 
as  follows: — His  friend  and  colleague,  Dr.  A.,  was  attending  a  patient,  Mr.  B.,  who  seems 
to  have  been  the  first  to  make  the  attempt  in  question ;  impressed  with  the  necessity  of 
taking  due  precautions,  Dr.  A.  then  visited  Dr.  C.,  in  whose  hearing  he  gave  directions  to 
have  the  windows  properly  secured,  as  Mr.  B.  had  attempted  to  throw  himself  out.     Now 
Dr.  C.  distinctly  remembers,  that  although  he  had  not  previously  experienced  any  such 
desire,  it  came  upon  him  with  great  urgency  as  soon  as  ever  the  idea  was  thus  suggested 
to  him ;  his  mind  being  just  in  that  state  of  incipient  delirium,  which  is  marked  by  the 
temporary  dominance  of  some  one  idea,  and  by  the  want  of  voluntary  power  to  withdraw 
the  attention  from  it.     And  he  deemed  it  probable  that,  as  Dr.  A.  went  on  to  Mr.  D.,  Dr. 
E.,  &c.,  and  gave  similar  directions,  alike  desire  would  be  excited  in  the  minds  of  all 
those  who  might  happen  to  be  in  the  same  impressible  condition. 

2  In  true  Dreaming,  the  sensational  consciousness  is  entirely  closed  to  the  outward  world; 
and  all  the  images  which  we  may  believe  we  see,  or  the  sounds  that  we  fancy  ourselves  to 
hear,  seem  to  result  from  changes  in  the  Sensorium  excited  by  Cerebral  influence ;  but  in 
Delirium  there  is  an  evidently  disordered  action  of  the  Sensorium  itself,  of  which  spectral 
illusions  and  other   'subjective  sensations'  are  the  manifestation.     This  is  particularly 
obvious  in  that  form  of  Delirium  which  is  known  as  delirium  tremens. 


628  FUNCTIONS    OF   THE   CEItEimO-SPINAL   NERVOUS    SYSTEM. 

general  emotional  excitability,  that  nothing  is  felt  as  it  should  be,  and  the  most 
violent  passion  may  be  aroused  and  sustained  by  the  most  trivial  incidents,  or  by 
the  wrong  ideas  which  are  formed  by  the  mind  as  a  consequence  of  their  misin- 
terpretation (§  623).  Between  these  two  opposite  states,  and  that  in  which  the 
disturbance  affects  at  the  same  time  the  intellectual  and  the  emotional  part  of  the 
Mental  nature,  there  is  a  complete  succession  of  transitional  links;  but  under  all 
phases  of  this  condition  (these  often  passing  into  each  other  in  the  same  individ- 
ual), there  is  one  constant  element,  namely,  the  deficiency  of  Volitional  control 
over  the  succession  of  thought.  This  deficiency  appears  to  be  a  primary  element 
in  those  forms  which  essentially  consist  in  Intellectual  disturbance;  whilst  in 
those  of  which  Emotional  excitement  is  the  prominent  feature,  it  seems  rather  to 
result  from  the  overpowering  mastery  that  is  exercised  over  the  Will  by  the 
states  of  uncontrollable  passion  which  succeed  each  other  with  little  or  no 
interval.  It  sseems  probable,  however,  from  the  phenomena  of  Intoxication 
(§  702),  that  the  very  same  agency  which  is  the  cause  of  the  undue  Emotional 
excitability,  also  tends  to  produce  an  absolute  diminution  in  the  power  of  Voli- 
tional control. 

705.  From  the  state  of  Mania,  we  naturally  pass  to  those  more  persistent 
forms  of  Insanity,  in  which  there  is  some  settled  disorder  in  the  action  of  the 
Mind.  Although  this  may  arise  from  the  perversion  of  any  part  of  the  psychical 
nature,  yet  a  partial  or  complete  deficiency  in  the  Volitional  control  over  the  cur- 
rent of  thought,  and  consequently  over  the  actions  which  are  the  expressions  of 
it,  seems  to  be  a  characteristic  feature  of  every  form  of  Insanity,  and  is  frequently 
its  first  manifestation  ;  and  it  is  this,  which,  in  so  far  as  it  exists,  ought  to  be 
considered  as  rendering  the  individual  irresponsible  for  his  conduct.  But  with 
this  is  associated  an  excessive,  deficient,  or  perverted  activity  of  some  one  or 
more  of  the  automatic  tendencies ;  and  hence  Insanity  must  be  regarded  to  that 
extent  as  consisting  in  a  disordered  action  of  the  Cerebrum.  This  may  be  traced 
to  a  great  variety  of  causes,  which  may  be  classified  in  different  ways,  according 
as  we  take  their  own  nature  or  their  modus  operandi  as  the  basis  of  our  arrange- 
ment. Thus  it  is  unquestionable  that  in  a  large  proportion  of  cases  of  settled 
Insanity,  there  is  an  impairment  of  the  due  Nutrition  of  the  Cerebrum ;  and 
this,  which  is  often  an  hereditary  defect,  may  arise  de  novo,  like  abnormal 
changes  in  the  nutrition  of  other  parts  (CHAP.  Vin.),  from  deficiency  or  perver- 
sion in  the  formative  power  of  the  tissue,  or  from  an  imperfect  supply,  or  from 
an  altered  character  of  its  pabulum.  Of  the  influence  of  deficient  or  perverted 
formative  power  in  the  tissue,  we  have  examples  in  the  insanity  resulting  from 
mechanical  injuries  of  the  brain,  and  from  excessive  'wear'  of  the  organ  by 
forced  activity.  Of  the  effects  of  deterioration  in  the  character  of  the  blood,  we 
have  illustrations  in  the  Insanity  that  is  often  linked-on  with  constitutional 
diseases  of  which  such  deterioration  is  a  marked  feature,  and  in  that  which  is  so 
frequent  a  consequence  of  habitual  excess  in  the  use  of  Alcoholic  liquors. 
These  conditions  may  exist  in  combination  ;!  and  it  is,  probably,  by  such  a  com- 
bination, that  many  of  the  'moral  causes'  of  Insanity  operate.  For  there  can 
be  little  doubt  that  Emotional  excitement,  from  its  immediate  relation  to  Nerve- 
force  (§  624),  has  a  direct  influence  on  the  formative  capacity  of  the  Cerebrum ; 

1  Thus  Delirium  tremens,  which  may  be  regarded  as  a  form  of  temporary  Insanity, 
essentially  consisting  in  perverted  and  imperfect  nutrition  of  the  Cerebrum,  seems  ordi- 
narily to  depend  conjointly  upon  the  excessive  and  irregular  activity  to  which  the  organ 
has  been  previously  forced,  and  on  the  alteration  of  the  normal  character  of  the  Blood 
produced  by  the  habitual  presence  of  Alcohol  in  its  current ;  but  it  is  well  known  that 
Delirium  Tremens  may  occur  as  the  result  of  other  agencies  that  primarily  depress  the 
nutritive  powers  without  perverting  the  blood  ;  such  as  excessive  depletion,  the  shock  of 
severe  injuries,  or  extreme  cold.  In  either  case,  however,  the  indications  of  treatment 
are  the  same ;  namely,  to  induce  sleep,  whereby  the  irregular  activity  of  the  organ  may 
be  completely  suspended,  and  its  due  nutrition  restored ;  and  to  correct  what  may  be 
faulty  in  the  condition  of  the  Blood. 


ABNORMAL   MODES    OF    CEREBRAL   ACTIVITY  : — INSANITY.  629 

whilst,  on  the  other  hand,  we  know  that  it  has  so  great  an  influence  over  the 
Organic  functions,  that  it  can  produce  very  decided  alterations  in  the  condition 
of  the  Blood  (CHAP.  xv).  But  without  any  serious  perversion  of  the  nutrition 
of  the  Cerebrum,  its  action  may  be  disturbed,  either  by  the  presence  of  some 
toxic  agent  in  the  Blood,  or  by  functional  disturbance  in  other  parts  of  the 
Nervous  system.  The  delirium  of  Intoxication  is,  whilst  it  lasts,  a  true  Insanity; 
and  it  ceases  because  the  poison  is  eliminated  from  the  circulation.  But  there 
are  many  cases  in  which  there  is  a  continual  production  of  a  poison  within  the 
system,  which  deranges  the  normal  train  of  mental  action  so  long  as  the  blood  is 
tainted  by  it;  the  indication  of  treatment  is  here  obviously  to  check  this  pro- 
duction, and  to  depurate  the  blood ;  and  when  this  has  been  effectually  accom- 
plished, the  healthy  action  of  the  Brain  is  immediately  restored,  which  would 
not  have  been  the  case  if  its  nutrition  had  been  seriously  impaired.  Most  per- 
sons have  experienced  the  extreme  depression  of  spirits  and  incapacity  for  mental 
exertion,  which  are  consequent  upon  certain  derangements  of  the  digestive 
function,  and  especially  upon  disorder  of  the  biliary  apparatus ;  and  it  is 
unquestionable  that  many  forms  of  Insanity,  in  which  extreme  dejection  is  a 
prominent  symptom,  but  which  may  also  include  intellectual  delusions,  are  solely 
dependent  upon  this  cause.  The  functional  disturbance  of  the  Cerebrum  induced 
by  the  irregular  action  of  other  parts  of  the  Nervous  System,  is  a  part  of  the 
Etiology  of  Insanity  which  has  been  as  yet  but  very  little  attended-to,  but  which 
deserves  a  careful  study.  Numerous  examples  of  it  are  furnished  by  certain 
peculiar  forms  of  disordered  Mental  action,  which  are  connected  with  *  hysterical' 
states  of  the  female  system,  especially  mutability  and  irritability  of  temper  and 
disposition  to  deceit ;'  but  we  are  probably  also  to  refer  to  this  cause,  in  part  at 
least,  those  very  distressing  states  of  mind,  which  arise  out  of  disorders  in  the 
sexual  apparatus  of  the  male,  or  even  from  irritation  of  neighbouring  parts.2 — It 
frequently  happens  that  agencies  of  both  classes  contribute  to  the  result;  some 
long-continued  defect  of  nutrition  (very  often  arising  from  hereditary  constitu- 
tion) serving  as  the  '  predisposing  cause,'  whilst  violent  mental  emotion,  or  de- 
pravation of  the  blood  by  noxious  matter  of  some  kind,  acts  as  the  *  exciting 
cause ;'  the  two  conjointly  producing  that  effect,  which  neither  would  singly  have 
brought-about. 

706.  It  is  chiefly  (but  not  solely)  in  those  cases  in  which  the  Cerebral  powei 
has  been  weakened  by  a  succession  of  attacks  of  Mania,  Epilepsy,  or  some  other 
disorder  which  consists  in  a  perverted  action  of  the  whole  organ,  that  we  find  the 
Intellectual  powers  specially  and  permanently  disordered ;  the  succession  of  thought 
becoming  incoherent,  and  the  perception  of  those  relations  of  ideas  on  which  all 
reasoning  processes  depend,  being  more  or  less  completely  obscured.  The  failure 
usually  shows  itself  first  in  the  power  of  Volitional  direction,  and  especially  in  the 
faculty  of  Recollection ;  in  proportion  as  the  mind  is  unable  to  bring  the  results 
of  past  experience  to  bear  on  its  present  operations,  do  these  lose  their  connected- 
ness and  consistency;  and  at  last  all  the  ordinary  links  of  association  appear  to  be 
severed,  and  (as  in  the  most  incoherent  kinds  of  Dreaming)  the  succession  of 
thoughts  cannot  be  accounted-for  on  any  known  principles  of  psychical  action. 
All  this  may  occur  with  or  without  Emotional  excitement;  not  unfrequently  the 
latter  occurs  in  paroxysms,  which  interrupt  the  otherwise  tranquil  life  of  the  sub- 
jects of  this  form  of  Insanity ;  and  it  is  not  at  all  incompatible  with  this  condition, 
that  there  should  be  a  special  excitability  upon  some  one  point,  which,  owing  to 
the  annihilation  of  the  Volitional  controlling  power,  acquires  a  temporary  pre- 
dominance whenever  it  is  called  into  play.  It  is  the  general  characteristic,  how- 

1  See  Dr.  Laycock's  "  Treatise  on  the  Nervous  Diseases  of  Women,"  in  which  these  sym- 
pathies are  fully  dwelt  on.  , 

-  See  M.  Lallemand's  "  Treatise  on  Spermatorrhoea,"  translated  by  Mr.  McDougal. — ID 
some  of  the  cases  recorded  by  M.  Lallemand,  the  most  extreme  mental  depression  was 
engendered  by  the  presence  of  ascarides  in  the  rectum  ! 


630  FUNCTIONS    OF    THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

ever,  of  this  form  of  Insanity,  that  there  are  no  settled  delusions ;  the  mind  not 
being  disposed  to  dwell  long  upon  any  one  topic,  but  wandering-off  in  a  rambling 
manner,  so  as  speedily  to  lose  all  trace  of  the  starting-point.  Such  patients  are 
unable  to  recollect  what  passed  through  their  thoughts  but  a  few  minutes  pre- 
viously j  if  any  object  of  desire  be  placed  before  them,  which  it  requires  a  con- 
sistent reasoning  process  to  attain,  they  are  utterly  unable  to  carry  this  through ; 
and  the  direction  of  their  desires  is  perpetually  varying,  and  may  be  readily 
altered  by  external  suggestion.  Cases  of  Intellectual  Insanity,  depending  (as 
this  form  of  the  disease  usually  does)  upon  structural  disorder  of  the  Cerebrum, 
are  less  amenable  to  treatment  than  are  those  of  the  other  forms  presently  to  be 
described ;  and  their  tendency  is  usually  towards  complete  fatuity. 

707.  There  may,  however,  be  no  primary  disorder  of  the  Intellectual  faculties ; 
and  the  Insanity  may  essentially  consist  in  a  tendency  to  disordered  Emotional 
excitement;   which  affects  the  course  of  thought,  and  consequently  of  action, 
without  disturbing  the  reasoning  processes  in  any  other  way  than  by  supplying 
wrong  materials  to  them.     Now  the  emotional  disturbance  may  be  either  general 
or  special;  that  is,  there  may  be  a  derangement  of  feeling  upon  almost  every 
subject,  matters  previously  indifferent  becoming  invested  with  strong  pleasurable 
or  painful  interest,  things  which  were  previously  repulsive  being  greedily  sought, 
and  those  which  were  previously  the  most  attractive  being  in  like  manner  repelled  ; 
or,  on  the  other  hand,  there  may  be  a  peculiar  intensification  of  some  one  class 
of  feelings  or  impulses,  which  thus  acquire  a  settled  domination  over  the  whole 
character,  and  cause  every  idea  with  which  they  connect  themselves  to  be  pre- 
sented to  the  mind  under  an  erroneous  aspect.     The  first  of  these  forms,  now 
generally  termed  Moral  Insanity,  may  and  frequently  does  exist  without  any 
disorder  of  the  Intellectual  powers,  or  any  delusion  whatever;  it  being  (as  we 
shall  presently  see)  a  result  of  the  generality  of  the  affection  of  the  Emotional 
tendencies,  that  no  one  of  them  maintains  any  constant  hold  upon  the  mind,  one 
excitement  being  (as  it  were)  driven-out  by  another.     Such  patients  are  among 
those  whose  treatment  requires  the  nicest  care,  but  who  may  be  most  benefitted 
by  judicious  influences.     Nothing  else  is  requisite,  than  that  they  should  exercise 
an  adequate  amount  of  self-control ;  but  the  best-directed  moral  treatment  cannot 
enforce  this,  if  the  patient  do  not  himself  (or  herself)  co-operate.     Mufch  may 
be  effected,  however,  as  in  the  education  of  children,  by  presenting  adequate 
motives  to  self-control ;   and  the  more  frequently  this  is  exerted,  the  more  easy 
does  the  exertion  become. 

708.  The  more  limited  and  settled  disorder  of  any  one  portion  of  the  Emotional 
nature,  however,  gives  an  entirely  different  aspect  to  the  character,  and  produces 
an  altogether  dissimilar  effect  upon  the  conduct.     It  is  the  essential  feature  of 
this  state,  that  some  one  particular  tendency  acquires  a  dominance  over  the  rest; 
and  this  may  happen,  it  would  seem,  either  from  an  extraordinary  exaggeration 
of  the  tendency,  whereby  it  comes  to  overmaster  even  a  strongly-exercised  Voli- 
tional control ;  or,  on  the  other  hand,  from  a  primary  weakening  of  the  Volitional 
control,  which  leaves  the  predominant  bias  of  the  individual  free  to  exercise  itself. 
Again,  the  exaggerated  tendency  may  operate  (like  an  ordinary  Emotion),  either 
in  directly  prompting  to  some  kind  of  action  which  is  the  expression  of  it,  or  in 
modifying  the   course  of  thought,  by  habitually  presenting  erroneous  notions 
upon  the  subjects  to  which  the  disordered  feeling  relates,  as  the  basis  of  Intel- 
lectual operations. — The  first  of  these  forms  of  Monomania  is  that  which  is 
known  as  impulsive  Insanity;  and  the  recognition  of  its  existence  is  of  peculiar 
importance  in  a  juridical  point  of  view.     For  whilst  the  Law  of  England  only 
recognizes  as  irresponsible,  on   the  ground  of  Insanity,  those  who  are  incapable 
of  distinguishing  right  from  wrong,  or  of  recognizing  the  consequences  of  their 

a  This  form  of  Insanity  is  particularly  common  among  females  of  naturally  '  quick  tem- 
Der,'  who,  by  not  placing  an  habitual  restraint  upon  themselves,  gradually  cease  to  retain 
auy  command  over  it. 


ABNORMAL    MODES    OF   CEREBRAL   ACTIVITY: — INSANITY. 

acts,  it  is  unquestionable  that  many  criminal  actions  are  committed  under  the 
irresistible  dominance  of  some  insane  impulse,  the  individual  being  at  the  time 
perfectly  aware  of  their  evil  nature  and  of  his  amenableness  to  punishment.1 
Such  an  impulse  may  lead  the  subject  of  it  to  kill,  to  commit  a  rape,  to  steal,  to 
burn,  and  so  on,  and  this  without  the  least  intention  of  doing  injury  to  another; 
and  many  instances  have  occurred,  in  which  the  individuals  thus  affected  have 
voluntarily  withdrawn  themselves  from  the  circumstances  of  whose  exciting 
influence  they  were  conscious,  and  have  even  begged  to  be  put  under  restraint. 
— It  is  a  remarkable  fact,  moreover,  and  one  that  strikingly  confirms  the  view 
of  the  nature  of  Emotional  states  which  has  been  here  advocated,  that  the  insane 
impulse  appears  to  be  not  unfrequefltly  the  expression  of  a  dominant  idea,  with 
which  there  is  no  such  association  of  pleasurable  feeling  as  makes  the  action 
prompted  by  it  an  object  of  desire,  but  which  operates  by  taking  full  possession 
of  the  mind,  and  by  forcing  (so  to  speak)  the  body  into  the  movements  which 
express  it.  The  individual  thus  affected  regards  himself  as  the  victim  of  a 
necessity  which  he  cannot  resist,  and  may  be  perfectly  conscious  (as  when  the 
impulse  proceeds  from  a  strong  desire)  that  what  he  is  doing  will  be  injurious  to 
others  or  to  himself.  This  state  bears  a  close  resemblance  to  that  of  the  f  biolo- 
gized' subject,  who  is  peremptorily  told,  "  You  must  do  this,"  and  does  it  accord- 
ingly (§  672) ;  and  it  is  one  that  is  particularly  liable  to  be  induced  in  persons 
who  habitually  exercise  but  little  Volitional  control  over  the  direction  of  their 
thoughts,  by  the  influence  of  suggestions  from  without,  and  especially  by  occur- 
rences which  fix  themselves  strongly  upon  their  attention.2 

1  The  following  very  characteristic  example  of  the  Homicidal  form  of  impulsive  Insanity, 
is  given  in  the  Report  of  the  Morningside  (Edinburgh)  Lunatic  Asylum  for  the  year  1850. 
— The  case  was  that  of  a  female,  who  was  not  aifected  with  any  disorder  of  her  intellectual 
powers,  and  who  laboured  under  no  delusions  or  hallucinations,  but  who  was  tormented 
by  "  a  simple  abstract  desire  to  kill,  or  rather,  for  it  took  a  specific  form,  to  strangle.     She 
made  repeated  attempts  to  effect  her  purpose,  attacking  all  and  sundry,  even  her  own  nieces 
and  other  relatives ;   indeed,  it  seemed  to  be  a  matter  of  indifference  to  her  whom  she 
strangled,  so  that  she  succeeded  in  killing  some  one.     She  recovered,  under  strict  discipline, 
BO  much  self-control  as  to  be  permitted  to  work  in  the  washing-house  and  laundry :  but 
she  still  continued  to  assert  that  she  'must  do  it,'  that  she  was  'certain  she  would  do  it 
some  day,'  that  she  could  not  help  it,  that  'surely  no  one  had  ever  suffered  as  she  had 
done,' — was  not  hers  '  an  awful  case;'  and,  approaching  any  one,  she  would  gently  bring 
her  hand  near  their  throat,  and  say  mildly  and  persuasively,  '  I  would  just  like  to  do  it.' 
She  frequently  expressed  a  wish  that  all  the  men  and  women  in  the  world  had  only  one 
neck,  that  she  might  strangle  it.     Yet  this  female  had  kind  and  amiable  dispositions,  was 
beloved  by  her  fellow-patients,  so  much  so  that  one  of  them  insisted  on  sleeping  with  her, 
although  she  herself  declared  that  she  was  afraid  she  would  not  be  able  to  resist  the 
impulse  to  get  up  during  the  night  and  strangle  her.     She  had  been  a  very  pious  woman, 
exemplary  in  her  conduct,  very  fond  of  attending  prayer-meetings,  and  of  visiting  the 
sick,  praying  with  them,  and  reading  the  Scriptures,  or  repeating  to  them  the  sermons 
she  had  heard.     It  was  the  second  attack  of  insanity.    During  the  former,  she  had  attempted 
Buicide.     The  disease  was  hereditary,  and  it  may  be  believed  that  she  was  strongly  pre- 
disposed to  morbid  impulses  of  this  character,  when  it  is  stated  that  her  sister  and  mother 
ooth  committed  suicide.     There  could  be  no  doubt  as  to  the  sincerity  of  her  morbid  desires. 
She  was  brought  to  the  Institution  under  very  severe  restraint,  and  the  parties  who  brought 
her  were  under  great  alarm  upon  the  restraint  being  removed.     After  its  removal,  she 
made  repeated  and  very  determined  attacks  upon  the  other  patients,  the  attendants,  and 
the  officers  of  the  Asylum,  and  was  only  brought  to  exercise  sufficient  self-control  by  a 
system  of  rigid  discipline.      This  female  was   perfectly  aware  that  her  impulses  were 
wrong,  and  that  if  she  had  committed  any  act  of  violence  under  their  influence,  she  would 
have  been  exposed  to  punishment.     She  deplored,  in  piteous  terms,  the  horrible  propensity 
under  which  she  laboured." — In  the  Report  of  the  same  Institution  for  1853,  it  is  men- 
tioned that  this  female  had  been  re-admitted,  after  nearly  succeeding  in  strangling  her 
Bister's  child  under  the  prompting  of  her  homicidal  impulse.     "She  displays  no  delusion 
or  perversion  of  ideas,  but  is  urged-on  by  an  abstract  and  uncontrollable  impulse  to  dc 
idm-t  she  knows  to  be  wrong,  and  deeply  deplores." 

2  To  this  condition  are  to  be  referred  many  of  the  insane  actions  which  are  commonly 
Set-down  to  the  account  of  Imitation.     This  term  would  be  best  restricted  to  that  state  of 
mind,  in  which  there  is  an  intention  to  imitate;  for  what  is  called  'involuntary  imitation 


632  FUNCTIONS    OF   THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

709.  In  most  forms  of  Monomania,  however,  there  is  more  or  less  of  disorder 
in  the  Ideational  process,  leading  to  the  formation  of  positive  delusions  or  hallu- 
cinations, that  is  to  say,  of  fixed  beliefs  or  '  dominant  ideas/  which  are  palpably 
inconsistent  with  reality.  These  delusions  are  not  attributable  to  original  per- 
versions of  the  reasoning  process,  but  arise  out  o/the  perverted  Emotional  state. 
This  gives-rise,  in  the  first  place,  to  a  mis-interpretation  of  actual  occurrences  in 
accordance  with  the  prevalent  state  of  the  feelings  (§  623) ;  but  when  the  dis- 
order has  lasted  some  time,  ideas  which  have  had  their  origin  in  the  Imagination 
alone,  and  which  it  has  at  first  presented  under  a  very  transient  aspect,  are  habitu- 
ally dwelt-upon  in  consequence  of  the  interest  with  which  they  are  invested,  and 
at  last  become  realities  to  the  consciousness  t)f  the  individual,  simply  because  he 
has  not  brought  them  to  the  test  of  actual  experience.1  When  the  mind  has 

is  merely  the  expression  of  the  fact,  that  the  consciousness  of  the  performance  of  a  certain 
act  by  one  individual,  gives-rise  to  a  tendency  to  its  performance  by  the  other.  Thus  the 
excitement  of  the  act  of  yawning  by  the  sight  or  sound  of  it  in  another,  is  a  simple  phe- 
nomenon of  consensual  movement  proceeding  from  an  exciting  sensation.  And  in  like  man- 
ner, the  commission  of  suicide  or  homicide,  after  an  occurrence  of  the  same  kind  which 
has  previously  fixed  itself  strongly  upon  the  attention,  is  an  ideo-motor  action,  prompted 
by  a  suggesting  idea.  Thus,  it  is  well  known  that  after  the  suicide  of  Lord  Castlereagh,  a 
large  number  of  persons  destroyed  themselves  in  a  similar  mode.  Within  a  week  after 
the  "  Pentonville  Tragedy,"  in  which  a  man  cut  the  throats  of  his  four  children  and  then 
his  own,  there  were  two  similar  occurrences  elsewhere.  After  the  trial  of  Henriet.te  Cor- 
nier for  child-murder,  which  excited  a  considerable  amount  of  public  discussion  on  the 
question  of  homicidal  insanity,  Esquirol  was  consulted  by  numerous  mothers,  who  were 
haunted  by  a  propensity  to  destroy  their  offspring. — The  following  is  a  remarkable  example 
of  the  sudden  domination  of  a  morbid  impulse,  to  which  no  tendency  seems  to  have  been 
previously  experienced,  and  which  appears  to  have  been  altogether  devoid  of  any  emotional 
character.  Dr.  Oppenheim,  of  Hamburgh,  having  received  for  dissection  the  body  of  a 
man  who  bad  committed  suicide  by  cutting  his  throat,  but  who  had  done  this  in  such  a 
manner  that  his  death  did  not  take  place  until  after  an  interval  of  great  suffering,  jokingly 
remarked  to  his  attendant, — "  If  you  have  any  fancy  to  cut  your  throat,  don't  do  it  in 
such  a  bungling  way  as  this ;  a  little  more  to  the  left  here,  and  you  will  cut  the  carotid 
artery."  The  individual  to  whom  this  dangerous  advice  was  addressed,  was  a  sober,  steady 
man,  with  a  family  and  a  comfortable  subsistence:  he  had  never  manifested  the  slightest 
tendency  to  suicide,  and  had  no  motive  to  commit  it.  Yet,  strange  to  say,  the  sight  of  the 
corpse,  and  the  observation  made  by  Dr.  0.,  suggested  to  his  mind  the  idea  of  self-destruc- 
tion ;  and  this  took  such  firm  hold  of  him  that  he  carried  it  into  execution,  fortunately, 
however,  without  duly  profiting  by  the  anatomical  instructions  he  had  received  ;  for  he  did 
not  cut  the  carotid,  and  recovered. 

1  The  Author  was  led,  several  years  since,  to  the  formation  of  the  view  above  enunciated 
with  regard  to  the  Emotional  source  of  most  if  not  all  the  delusions  of  the  Insane,  by  the 
careful  observation  of  a  case  in  which  the  gradual  formation  of  such  delusions  could  be 
traced,  and  in  which  the  varying  tenacity  of  their  hold  over  the  belief  (which  sometimes 
appeared  disposed  to  get  rid  of  them)  corresponded  exactly  with  varying  degrees  of  inten- 
sity of  the  dominant  emotion.  Having  been  led,  by  his  interest  in  this  case,  to  make  par- 
ticular inquiries  as  to  the  point  in  question,  among  those  whose  experience  of  Insanity  has 
been  far  more  extensive  than  his  own,  he  has  obtained  from  them  full  confirmation  of  the 
view  above  expressed.  Thus  Dr.  Skae  remarks  in  the  "  Morningside  Report"  for  1853, 
that  "  nothing  can  be  further  from  the  truth  than  to  believe  that  in  every  case  of  Insanity 
there  must  be  some  delusion,  or  some  perturbation  of  the  intellect.  Of  all  the  features  of 
Insanity,  morbid  impulses,  emotions,  and  feelings,  and  the  loss  of  control  over  them,  are  the 
most  essential  and  constant.  Delusions,  illusions,  and  hallucinations  are,  comparatively 
speaking,  the  accidental  concomitants  of  the  disease.  The  former,  perhaps,  invariably 
nccompany  the  invasion  of  the  disease ;  the  latter  are  frequently  only  developed  during  its 
progress,  and  are  sometimes  never  present  at  all."— It  is  not  a  little  interesting,  in  this 
connexion,  as  well  as  in  the  additional  relation  which  it  indicates  between  Insanity  and  the 
various  phases  of  Delirium,  Dreaming,  &c.,  that  the  particular  delusion  seems  often  to  be 
suggested  by  accidental  circumstances,  the  mind  being  previously  under  the  influence  of 
some  morbid  tendency  which  gave  the  general  direction  to  the  thoughts.  Thus  we  find  it 
mentioned  in  the  "  Morningside  Report,"  for  1850,  that  the  Queen's  public  visit  to  Scot- 
land seemed  to  give  a  special  direction  to  the  ideas  of  several  individuals  who  became 
insane  at  that  period,  the  attack  of  insanity  being  itself  in  some  instances  traceable  to  the 
excitement  induced  by  that  event.  One  of  the  patients,  who  was  affected  with  puerperal 
mania,  believed  that,  in  consequence  of  her  confinement  having  taken  place  on  fuch  a 


DISORDERED    EMOTIONAL     STATE: — HYSTERIA  633 

once  yielded  itself  up  to  the  dominance  of  these  erroneous  ideas,  they  c;in  seldom 
bj  dispelled  by  any  process  of  reasoning;  for  it  results  from  the  very  nature  of 
the  previous  habits  of  thought,  that  the  reasoning  powers  are  weakened,  and  that 
the  volitional  control,  through  want  of  exercise,  can  no  longer  be  exerted.1  And, 
consequently,  although  a  vigorous  determination  to  get-rid  of  the  ideas  which 
are  felt  to  be  erroneous,  and  to  keep-down  the  emotional  tendency  whose  exagge- 
ration is  the  essence  of  the  disorder, — in  other  words,  a  strong  effort  of  self-con- 
trol,— may  be  effective  in  an  early  stage  of  this  condition,  yet,  when  the  wrong 
hn bits  of  thought  have  become  settled,  little  can  usually  be  done  by  way  of  direct 
attack  upon  them ;  and  the  most  efficacious  treatment  consists  in  the  encourage- 
ment of  the  general  habit  of  self-control,  and  in  the  withdrawal  of  the  mind,  so 
far  as  may  be  possible,  from  the  morbid  state  of  action,  by  presenting  to  it  other 
sources  of  interesting  occupation.2 

710.  A  disordered  state  of  the  Emotional  nature  seems  to  be  an  essential  cha- 
racter of  that  condition  which  is  usually  designated  as  Hysteria.  There  are  cer- 
tain forms  of  this  disorder,  which  graduate  insensibly  into  Moral  Insanity  or 
Monomania;  but  it  more  commonly  manifests  itself,  in  the  first  instance  at  least, 
in  an  exaggeration  of  ordinary  emotional  excitement  and  of  its  external  manifes- 
tations, such  as  smiles  and  tears,  laughter  and  crying,  which  are  strangely  inter- 
mingled, and  are  brought-on  by  the  slightest  disturbance  of  the  feelings.  That 
the  deficiency  lies  rather  in  the  power  of  controlling  the  thoughts  and  feelings, 
than  in  that  of  directing  the  actions  of  the  muscles,  appears  from  the  fact  that 
Hysterical  patients  can  often  be  caused  to  restrain  themselves,  either  by  the  pre- 
sentation of  some  powerful  motive  (as  the  threat  of  severe  discipline  in  the  event 
of  the  return  of  the  paroxysm),  or  through  the  more  gradual  cultivation  of  the 
power  of  Will  in  repressing  the  first  access  of  emotional  excitement,  by  the  with- 
drawal of  the  mind  from  the  contemplation  of  all  that  induces  it.  For  in  such 
individuals,  the  involuntary  movements  are  but  the  expression  of  an  unhealthy 
state  of  mind;  in  which,  either  from  an  injudicious  system  of  education,  or  from 
habitual  want  of  self-control  on  the  part  of  the  individual,  the  Emotions  are 
allowed  to  exercise  unchecked  domination ;  and  in  which  the  Will  is  at  last  so 
weakened,  that  the  subject  of  the  disorder  can  scarcely  be  considered  as  a  respon- 
sible being.  There  are  other  Hysterical  cases,  again,  in  which  there  is  less  of 
mental  disorder,  but  a  greater  physical  excitability  of  the  nervous  system  (§  723)  ; 
so  that  most  violent  paroxysms  of  a  tetanic  or  epileptic  character  are  induced  by 
very  slight  stimuli;  and  any  emotional  excitement  may  act  as  one  among  these 
stimuli,  without,  however,  being  at  all  excessive  in  its  amount.  Here,  too,  the 

remarkable  occasion,  she  must  have  given  birth  to  a  person  of  royal  or  divine  dignity. 
During  the  religious  excitement  which  prevailed  at  the  time  of  the  '  disruption '  of  the 
Scottish  Church,  an  unusually-large  number  of  patients  were  admitted  into  the  various 
asylums  of  Scotland,  labouring  under  delusions  connected  with  religion  ;  the  disorder 
having  here  also  doubtless  commenced  in  an  exaggeration  of  this  class  of  feelings,  and  the 
erroneous  beliefs  having  been  formed  under  their  influence.  Again,  in  the  Report  of  the 
same  Institution  for  1851,  it  is  stated  that,  as  in  former  instances,  "the  current  topics  of 
the  day  gave  colouring  and  form  to  the  delusions  of  the  disordered  fancy.  We  have  thus 
had  no  less  than  five  individuals  admitted  during  the  year,  who  believe  themselves  the  vic- 
tims of  "  Mesmeric  agency," — a  sort  of  '  Mesmeric  mania  '  having  been  prevalent  in  Edin- 
burgh during  that  period, — "  three  of  the  inmates  talked  much  of  California,  and  of  the 
bags  full  of  gold  which  they  had  obtained  from  the  diggings  :  and  one  of  them  arrived  at 
the  persuasion  that  his  body  was  transmuted  into  gold."  —  That  Insanity  commences  in  a 
disordered  Emotional  state,  is  a  doctrine  long  since  advocated  by  M.  Guislain  ("Traite'1 
des  Phrenopathies,"  and  "  Le9ons  Orales  sur  les  Maladies  Mentales  ") ;  but  he  only  recog 
nizes  one  form  of  this  disorder,  that  of  painful  sensibility  of  mind. 

1  If  an  attempt  be  made  to  reason  a  patient  out  of  a  delusion,  by  demonstrating  its  com 
jit  etc  inconsistency  with  the  most  obvious  facts,  the  reply  will  be  usually  something  to  this 
effect, — "  I  have  stronger  evidence  than  anything  which  you  can  urge — the  evidence  of  my 
own  feelings." 

•  See  an  excellent  little  essay  by  the  Rev.  J.  Barlow,  on  "  Man's  Power  over  himself  to 
prevent  or  control  Insanity." 


§34  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

Will  may  have  a  perfect  control  over  the  muscles,  at  all  other  times  th;m  wlion 
they  are  thrown  into  violent  action  by  the  reflex  excitability  of  the  Automatic 
centres;  and  the  treatment  of  such  cases  must  be  in  great  degree  directed  to 
the  removal  of  this  excitability,  which  frequently  depends  upon  some  morbid 
condition  of  the  uterus  or  ovaries.  At  the  same  time,  there  is  no  doubt  that  an 
habitually  perturbed  state  of  the  Emotions,  and  especially  in  those  relating  to 
sexual  love  (§  723,  note),  has  a  most  decided  influence  both  in  first  inducing  and 
in  subsequently  maintaining  this  automatic  excitability ;  and  that  whilst  mental 
tranquillity  and  self-regulation  are  almost  essential  to  recovery,  nothing  promotes 
it  so  much  as  the  supervention  of  a  more  favourable  state  of  feeling,  arising  out 
of  the  prospective  realization  of  desires  repressed  or  of  hopes  deferred.  Although 
Hysteria  is  so  much  more  common  in  the  female  than  in  the  male  sex,  that  it  has 
been  often  supposed  to  be  peculiar  to  the  former,  and  to  be  essentially  connected 
with  some  disordered  state  of  the  generative  function,  yet  there  is  no  doubt  of  its 
occasional  occurrence  in  the  latter  also;  and  its  greater  frequency  in  Woman  may 
be  fairly  attributed  to  the  greater  predominance  of  the  Emotional  element  in  her 
mental  constitution ;  as  well  as  to  the  circumstance,  that  in  all  that  relates  to 
sexual  love,  she  is  frequently  restrained  by  a  sense  of  decorum  from  giving  out- 
ward expression  to  feelings  which  she  is  secretly  brooding-over,  and  whose  injurious 
influence  she  is  exaggerating  by  the  attention  she  gives  to  them.  Where  the 
natural  vent  is  not  found  for  these  emotions  in  a  reciprocated  attachment,  the 
principle  formerly  laid-down  (§  640)  would  indicate,  that  the  mind  should  be  led 
to  seek-out  for  itself  other  objects  of  interest  sufficiently  attractive  to  solicit  its 
attention,  and  that  the  pent-up  excitement  should  be  encouraged  to  discharge 
itself  on  these;  and  experience  shows  that  such  is  a  most  important  part  of  the 
cure  for  these  states,  provided  that  motives  can  be  found  of  sufficient  strength 
to  influence  the  Will  to  exert  its  self-directing  power.1 

711.  The  disorder  of  the  Ideational  process  which  is  induced  by  Emotional 
perversion,  frequently  leads  to  the  formation  of  those  erroneous  notions  of  the 
nature  of  the  external  objects  whereby  the  subject  of  it  is  environed,  which  are 
commonly  termed  false  perceptions.  It  is  not  clear,  however,  how  far  the  act  of 
Perception  (using  this  term  in  the  sense  to  which  it  is  properly  restricted,  §  603) 
is  itself  perverted  in  such  cases;  and  it  is  certain  that  the  source  of  the  distor- 
tion frequently  lies,  chiefly  or  even  solely,  in  the  Emotional  medium  through 
which  the  perceptions  are  interpreted  (§  623).  Thus,  a  Lunatic  who  is  possessed 
with  an  exaggerated  feeling  of  his  own  importance,  may  suppose  himself  to  be  a 
sovereign  prince ;  and  under  the  influence  of  this  '  dominant  idea/  looks  upon 
the  place  of  his  confinement  as  his  palace,  believes  his  keepers  to  be  his  obse- 
quious officers,  and  his  fellow-patients  to  be  his  obedient  subjects;  the  plainest 
fare  is  converted  into  a  banquet  of  the  choicest  dainties,  and  the  most  homely 
dress  into  royal  apparel  His  condition,  therefore,  closely  corresponds  with  that 
of  a  'biologized'  subject,  whose  mind  may  become  ' possessed'  for  a  time  by 
similar  ideas,  through  the  influence  of  external  suggestion  (§  672),  and  who  is 
not  undeceived  by  their  discordance  with  objective  realities,  because  the  force 
with  which  the  consciousness  is  impressed  by  the  latter,  is  less  than  that  with 
which  it  is  acted-on  by  the  former.  Now  and  then,  perhaps,  the  lunatic,  like 
the  biologized  subject,  is  visited  by  a  gleam  of  common-sense,  which  enables  him 
to  view  certain  objects  in  their  true  light,  so  that  he  becomes  sensible  of  some 
inconsistency  between  his  real  and  his  imaginary  condition ;  thus,  a  patient  in  a 
Scotch  pauper-lunatic  asylum,  after  dilating  upon  the  imaginary  splendours  of 
his  regal  state,  confessed  that  there  was  one  thing  which  he  could  not  quite  com- 
prehend, namely,  that  all  his  food  tasted  of  oatmeal ! — It  is  not  only  in  Insanity, 
however,  that  we  witness  the  influence  of  dominant  ideas  or  feelings  in  producing 
a  misinterpretation  of  Sensational  states;  for  we  have  already  noticed  instances, 

1  For  a  sagacious  analysis  of  this  condition,  and  of  the  remedies  for  it,  see  a  small 
treatise  by  Mr.  R.  B.  Carter,  "  On  the  Pathology  aud  Treatment  of  Hysteria." 


DISORDER    OF    VOLITIONAL   POWER    OVER    MUSCLES: — CHOREA.        685 

LD  which  the  same  influence  was  apparent  in  the  ordinary  working  of  the  same 
mind  (§§  600,  601).  The  following  example  of  such  an  influence,  aifeeting 
several  individuals  simultaneously  in  a  similar  manner,  is  mentioned  by  Dr.  Hib- 
bert  in  his  well-kuown  Treatise  on  Apparitions.  A  whole  ship's  company  was 
thrown  into  the  utmost  consternation,  by  the  apparition  of  a  cook  who  had  died 
a  few  days  before.  He  was  distinctly  seen  walking  a-head  of  the  ship,  with  a 
peculiar  gait  by  which  he  was  distinguished  when  alive,  through  having  one  of 
his  legs  shorter  than  the  other.  On  steering  the  ship  towards  the  object,  it  was 
found  to  be  a  piece  of  floating  wreck. — Many  similar  cases  might  be  referred-to, 
in  which  the  imagination  has  worked-up  into  'apparitions'  some  common-placo 
objects,  which  it  has  invested  with  attributes  derived  from  the  previous  mental 
state  of  the  observer ;  and  the  belief  in  such  an  apparition  as  a  reality,  which 
usually  exists  in  such  cases,  unless  antagonized  by  an  eifort  of  the  reason,  con- 
stitutes a  delusion.  The  origin  of  such  delusions  is  thus  essentially  Cerebral  j 
whilst  that  of  pure  illusions  is  probably  Sensorial  (§  716).  In  many  cases,  how- 
ever, there  is  probably  a  disordered  action  of  both  centres  from  the  same  cause,  as 
is  obviously  the  case  in  those  forms  of  Delirium  which  have  a  toxic  origin  (§  702). ' 
712.  Without  any  Mental  perversion  indicative  of  either  structural  or  func- 
tional disorder  of  the  Cerebrum,  there  may  exist  a  partial  severance  of  its  con- 
nection with  the  motor  apparatus ;  so  that  there  is  a  weakening  of  Volitional 
power  over  the  muscles,  whilst  they  still  remain  amenable  to  the  stimulus  of 
Emotion,  which  seems  to  proceed  immediately  from  the  Sensory  Ganglia;  and 
in  such  cases,  as  might  be  expected,  the  influence  of  sensory  impressions  in 
directly  exciting  muscular  movements,  is  very  strongly  maiked.2  Of  the  precise 
alterations  which  give  rise  to  these  peculiar  conditions,  nothing  whatever  is 
known. — Nearly  allied  to  this  state  is  that  which  gives  rise  to  the  '  jactitating 
convulsion/  interfering  with  volitional  movement,  which  is  known  as  Chorea. 
On  the  physiological  views  here  advocated,  this  disease  must  be  regarded  as  con- 
sisting essentially  in  the  diminution  of  the  power  of  the  Will  (exerted  through 
the  Cerebrum)  over  the  muscular  apparatus,  concurrently  with  an  augmented 
and  perverted  activity  of  the  Sensori-motor  centres.  That  its  special  seat  is  at 
the  summit  of  the  Cranio-Spinal  axis,  where  it  comes  into  connection  with  the 

1  Two  interesting  Essays  on  '  Hallucinations,'  by  M.  Miche"a  and  Baillaiger,  will  be 
found  in  "Mem.  de  1'Acad.  Roy.  de  Medecine,"  torn.  xii. 

a  Of  this  curious  state,  the  following  example  was  communicated  to  the  Author,  some 
years  since,  by  his  friend  Dr.  Noble. — "  Mr.  R.  set.  41,  of  a  sanguine  nervous  tempera- 
ment, a  married  man,  and  father  of  several  children,  the  youngest  being  but  two  months 
old,  exhibited  the  following  symptoms,  first  experienced  in  a  slight  degree  about  five  years 
ago,  and  since  then  having  become  much  aggravated,  the  climax  having  apparently  been 
attained  about  two  years  ago. — There  was  partial  paralysis  of  voluntary  motion  upon  the 
left  side,  exhibiting  under  ordinary  circumstances  the  customary  phenomena  ;  but  with 
this  peculiarity, — that  although  Volition  was  comparatively  powerless,  any  incident  ex- 
citor  impression  of  an  unusual  character,  by  exciting,  as  it  were,  Consensual  action,  would 
give  eifect  to  the  voluntary  intention ;  thus,  "when  the  affected  arm  was  raised  by  another 
to  a  certain  height,  the  patient  was  unable  by  mere  volition  to  elevate  it  still  more ;  but 
if  the  hand  were  smartly  struck  or  blown-upon  either  by  himself  or  by  another,  move- 
ment of  a  rapid  character  would  at  once  ensue,  and  that  too  in  conformity  with  the 
volitional  effort.  Upon  inquiry,  moreover,  it  appeared  that  any  unwonted  impression 
upon  the  internal  as  well  as  the  external  senses  was  capable  of  leading  to  a  realization 
of  the  effort  vainly  attempted  by  the  mere  Will ;  hence  by  accomplishing  the  commence- 
ment of  a  run  or  trot  by  aid  of  some  undue  impression,  he  could  go  on;  he  stated,  on  the 
case  being  proposed,  that  if,  in  utter  paralysis  of  voluntary  power  over  the  muscles,  a 
hundred-pound  note  were  suddenly  placed  before  his  vision,  and  he  were  told  that  on 
seizing  it  the  same  should  be  his,  he  should  at  once  be  equal  to  the  requisite  effort — When 
in  health,  Mr.  R.  stated  that  he  had  excellent  controlling  power  over  the  Emotions,  but 
that  now  the  pleasure  and  the  pain  attendant  upon  their  excitation  were  exalted,  and  the 
consensual  phenomena  quite  irresistible ;  and  on  further  inquiry  it  appeared  that,  in  th<» 
matter  of  laughing  and  crying,  he  exhibited  very  much  of  the  hysterical  condition.  In 
early  life,  Mr.  R.  had  been  what  is  called  a  free  liver ;  both  in  regard  to  women,  and  to 
alcoholic  stimulants  " 


G36  FUNCTIONS    OF    THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

Cerebrum,  would  appear  from  several  considerations.,  particularly  from  the  inter- 
ruption of  voluntary  power,  the  aggravation  of  the  movements  by  emotion,  and 
their  cessation  during  sleep  ;  the  two  latter  facts  being  inconsistent  with  the  idea 
that  the  proper  Spinal  centres  are  essentially  involved,  although  they  are  fre- 
quently affected  coincidently  or  subsequently.  The  Choreic  convulsion  is  occa- 
sionally hemiplegic ;  and  it  sometimes  gives  place  to  paralysis,  which  is  seldom 
complete,  however,  and  may  usually  be  cured  by  appropriate  treatment.  This 
disorder  appears  generally  traceable  to  a  state  of  imperfect  nutrition,  dependent 
upon  a  depraved  and  perhaps  a  poisoned  state  of  the  blood,  rather  than  to  any 
organic  lesion.1  Not  unfrequently,  the  defect  of  nutrition  seems  to  act  as  the 
4 predisposing  cause'  of  the  disease;  the  attack  being  immediately  traceable  to 
mental  emotion.2 — But  there  are  other  states  of  less  intensity,  in  which  Emo- 
tional excitement  has  a  morbid  power  of  inducing  muscular  movements;  and 
this  not  through  any  deficiency  of  due  control  over  the  feelings,  but  often  con- 
currently with  a  want  of  power  to  bring  the  Will  to  bear  upon  the  muscles. 
Thus,  there  are  individuals  not  at  all  remarkable  for  their  emotional  excitability, 
who  cannot  avoid  making  the  most  extraordinary  grimaces  whenever  anything 
happens  which  in  the  least  disturbs  their  usual  equanimity,  notwithstanding  that 
they  may  put-forth  all  the  efforts  in  their  power  to  prevent  these.3  The  general 
muscular  agitation  of  the  confirmed  Stammerer  (§  821)  is  another  case  in  point; 
here  we  have  a  deficiency  in  the  power  of  the  Will  over  the  Muscles,  at  first 
displayed  only  in  regard  to  those  of  Voice ;  but  when  feelings  of  discomfort  have 
been  aroused  by  the  failure  of  attempts  to  articulate,  this  want  of  voluntary  con- 
trol extends  itself  to  the  muscular  system  in  general,  which  is  thrown  into  a  sort 
of  paroxysmal  effort,  that  usually  subsides  only  with  the  explosion  of  the  desi- 
derated sound. 

713.  The  Sensory  Ganglia,  collectively  constituting  the  Sensurivm,  may  be 
regarded  as  the  most  essential  part  of  the  Encephalon  ;  since  we  find  them  fully 
developed  in  animals  which  scarcely  possess  a  rudiment  of  a  Cerebrum,  and  pre- 
senring  the  same  relative  condition  to  the  latter  in  the  early  embryo  of  Man. 
They  directly  receive  the  nerves  proceeding  from  the  organs  of  Special  Sense, 
each  pair  of  which  has  its  own  distinct  ganglionic  centre ;  and  they  receive  also, 
through  the  (so-called)  Crura  Cerebri,  the  nerves  of  '  common  sensation/  whose 
ganglionic  centre  appears  to  lie  in  the  Thalami  Optici.  They  give-off  a  large 
number  of  motor  fibres,  which,  descending  through  the  Crura  Cerebri,  are 
distributed,  with  the  fibres  proceeding  from  the  Spinal  Ganglia,  through  the 
various  motor  trunks,  to  the  muscular  system  generally.  On  the  other  hand, 
by  one  set  of  the  radiating  fibres  of  the  Cerebral  substance,  they  transmit  senso- 
rial  impressions  upwards  to  the  vesicular  surface  of  the  Hemispheres ;  whilst 
conversely,  by  its  descending  fibres,  they  receive  the  impressions  transmitted 
downwards  from  the  Cerebral  ganglia ;  and  they  thus  constitute  the  medium  by 
which  alone  the  Cerebrum  communicates  with  the  Organs  of  Sense  on  the  one 
hand,  and  with  the  Muscular  apparatus  on  the  other. — The  Sensory  Ganglia 

1  See  Dr.  Todd's  Lumleian  Lectures  « On  the  Pathology  and  Treatment  of  Convulsive 
Diseases'  in  the  "  Medical  Gazette,"  April  20  and  27,  1849. 

a  A  remarkable  number  of  cases  of  Chorea  were  admitted  into  the  Bristol  Infirmary 
within  a  few  weeks  after  the  memorable  Riots  of  1833. 

3  The  Author  has  at  present  a  case  under  his  observation,  in  which  not  merely  the 
face,  but  the  body  and  limbs,  are  thrown  into  the  most  extraordinary  contortions,  upon 
any  agitation  of  the  feelings,  however  trifling.  This  gentleman,  a  man  of  education  and 
intelligence,  of  extreme  benevolence  of  character,  end  a  mind  habitually  well-regulated, 
can  scarcely  walk  the  streets  without  being  liable  to  the  induction  of  paroxysms  of  this 
kind,  by  causes  that  could  scarcely  have  been  supposed  capable  of  thus  operating.  For 
example,  he  was  one  day  seized  by  one  of  these  attacks,  in  consequence  of  seeing  a 
man  miss  his  footing  (as  he  thought)  in  descending  from  the  top  of  an  omnibus ;  and 
the  pleasurable  excitement  of  meeting  a  friend  usually  induces  the  same  result.  The 
tendency  varies  very  considerably  in  its  degree,  according  to  the  general  condition  of  his 
health. 


INDEPENDENT   ACTIVITY   OF   SENSORI-MOTOR    CENTRES.  637 

must  be  regarded  as  collectively  forming  the  Sensorium,  through  whose  instru- 
mentality the  Mind  is  rendered  conscious  of  impressions  made  on  the  Organs  of 
Sense ;  and  reasons  have  been  advanced  for  the  belief,  that  it  also  serves  as  the 
instrument  whereby  the  Consciousness  is  affected  by  Cerebral  changes,  which,  in 
so  far  as  they  take  place  independently  of  the  Will,  are  the  cause  and  not  the 
consequence  of  Mental  activity.  This  impression  on  the  consciousness,  when 
made  by  an  external  agency  operating  through  the  sensory  nerves,  is  that  which 
is  known  as  Sensation :  but,  when  produced  by  Cerebral  changes,  it  constitutes 
Ideation.  With  these  states  of  consciousness  are  directly  associated  the  simple 
feelings  of  pleasure  and  pain,  together  with  other  modes  of  sensibility,  which 
are  designated  as  ^Esthetic,  Moral,  Emotional,  &c. ;  together  with  that  direct 
perception  of  reality,  whether  in  the  external  universe  (objective),  or  in  the 
world  of  ideas  (subjective),  which  is  termed  Intuition.  The  seat  of  affections 
of  the  consciousness  which  are  so  directly  linked-on  to  Sensations  as  with  diffi- 
culty to  be  separated  from  them,  can  scarcely  be  other  than  Sensorial. — The 
'  reflex  action '  of  the  Sensory  Ganglia,  which  proceeds  from  their  own  inde- 
pendent activity,  is  manifested  in  all  those  automatic  movements,  which  are 
excited  through  sensations,  and  which  may  hence  be  designated  as  consensual  or 
sensori-motor.  These  actions  are  but  little  noticed,  in  Man,  in  the  active  state 
of  his  Cerebrum;  for  the  automatic  movements  on  which  the  maintenance  of 
his  organic  functions  is  immediately  dependent,  are  provided-for  by  the  Spinal 
centres ;  and  the  purposes  which  are  answered  in  the  lower  animals  by  the  higher 
order  of  Instinctive  actions,  are  worked-out  in  him  by  the  Intelligence.  There 
is,  however,  a  large  group  of  secondarily-automatic  movements,  which  though 
originally  determined  by  the  Will,  are  brought  by  habit  so  far  under  the  direct 
influence  of  sensations,  that  they  continue,  whilst  prompted  and  guided  by  the 
latter,  after  the  Will  has  ceased  to  act. — The  operation  of  the  Sensory  Ganglia 
in  Man  is  usually  subservient  to  that  of  the  Cerebrum ;  for  the  influence  of  Sen- 
sational changes,  being  propagated  upwards  to  that  organ,  excites  further  changes 
in  it;  these,  reflected  downwards  to  the  Seusori-motor  centres,  become  the  sources 
of  ideational  or  of  emotional  movements;  and  the  determining  power  of  the 
Will,  in  producing  volitional  movements,  is  exercised  through  the  same  channel. 
It  is  a  remarkable  indication  of  the  participation  of  the  Sensorial  centres  even 
in  volitional  movement,  that  these  cannot  be  executed  save  with  the  concurrence 
of  guiding  sensations. 

714.  The  extent  to  which  the  Sensory  Ganglia  may  act  as  independent  centres 
of  action,  is  best  seen  in  cases  in  which  the  functions  of  the  Cerebrum  are  en- 
tirely in  abeyance.  This  may  happen  through  congenital  defect,  as  in  some 
cases  of  complete  Idiocy,  especially  among  the  Cretins  of  the  l  first  degree/  who 
spend  their  whole  time  in  basking  in  the  sun  or  sitting  by  the  fire  (experiencing 
merely  sensorial  pleasure),  and  who  show  no  higher  traces  of  intelligence,  than 
is  evinced  by  their  going,  when  excited  by  hunger,  to  the  places  where  they  have 
been  accustomed  to  receive  food.  It  may  occur,  too,  as  a  consequence  of  disease 
or  injury.  Of  this  we  have  an  example  in  a  case  mentioned  by  Dr.  Rush,  of  a 
man  who  was  so  violently  affected  by  some  losses  in  trade,  that  he  was  deprived 
almost  instantly  of  his  mental  faculties;  he  did  not  take  the  slightest  notice  of 
anything,  not  even  expressing  a  desire  for  food,  but  merely  receiving  it  when  it 
was  put  into  his  mouth ;  a  servant  dressed  him  in  the  morning,  and  conducted 
him  to  a  seat  in  his  parlour,  where  he  remained  the  whole  day,  with  his  body 
bent  forwards,  and  his  eyes  fixed  on  the  floor ;  in  this  state  he  continued  for  five 
years,  and  then  recovered  completely  and  rather  suddenly.  The  well-known  case 
of  a  sailor  who  suffered  for  more  than  a  year  from  depressed  fracture  of  the 
skull,  and  was  at  last  restored  to  his  normal  condition  by  the  elevation  of  the 
depressed  bone  (which  was  effected  by  Mr.  Cline),  affords  another  illustration  of 
the  same  suspension  of  cerebral  activity,  without  the  loss  of  sensorial  power; 
this  man  passed  the  period  between  the  accident  and  the  operation  in  a  condition 


638  FUNCTIONS   OF   THE   CEREBRO-SPINAL  NERVOUS   SYSTEM. 

very  similar  to  that  of  the  subject  of  the  preceding  case ;  and  after  hte  recovery, 
the  whole  intervening  space  was  a  perfect  blank  to  his  recollection.  The  most  re- 
markable example  of  this  condition,  however,  yet  put  on  record,  is  a  case  which 
occurred  a  few  years  ago  under  the  observation  of  Mr.  Dunn,1  of  whose  excellent 
account  an  abridgment  is  here  given,  for  the  sake  of  illustrating  the  nature  of  a 
purely  sensorial  and  instinctive,  as  distinguished  from  an  intelligent  existence, 
and  the  gradual  nature  of  the  transition  from  the  one  to  the  other.2  A  very 

1  «  Lancet,"  Nov.  15  and  29,  1845. 

3  The  subject  of  this  case  was  a  young  woman  of  robust  constitution  and  good  health, 
who  accidentally  fell  into  a  river  and  was  nearly  drowned.  She  remained  insensible  for 
six  hours  after  the  immersion ;  but  recovered  so  far  as  to  be  able  to  give  some  account  of 
the  accident  and  of  her  subsequent  feelings,  though  she  continued  far  from  well.  Ten 
days  subsequently,  however,  she  was  seized  with  a  fit  of  complete  stupor,  which  lasted  for 
four  hours ;  at  the  end  of  which  time  she  opened  her  eyes,  but  did  not  seem  to  recognize 
any  of  her  friends  around  her:  and  she  appeared  to  be  utterly  deprived  of  the  senses  of 
hearing,  taste,  and  smell,  as  well  as  of  the  power  of  speech.  Her  mental  faculties  seemed 
to  be  entirely  suspended  ;  her  only  medium  of  communication  with  the  external  world 
being  through  the  senses  of  sight  and  touch,  neither  of  which  appeared  to  arouse  ideas  in 
her  mind,  though  respondent  movements  of  various  kinds  were  excited  through  them. 
Her  vision  at  short  distances  was  quick ;  and  so  great  was  the  exaltation  of  the  general 
sensibility  upon  the  surface  of  the  body,  that  the  slightest  touch  would  startle  her;  still, 
unless  she  was  touched,  or  an  object  or  a  person  was  so  placed  that  she  could  not  help 
seeing  the  one  or  the  other,  she  appeared  to  be  quite  lost  to  everything  that  was  passing 
around  her.  She  had  no  notion  that  she  was  at  home,  not  the  least  knowledge  of  anything 
about  her ;  she  did  not  even  know  her  own  mother,  who  attended  upon  her  with  the  most 
unwearied  assiduity  and  kindness.  Wherever  she  was  placed,  there  she  remained  during 

the  day Her  appetite  was  good,  but  having  neither  taste  nor  smell,  she  ate 

alike  indifferently  whatever  she  was  fed  with,  and  took  nauseous  medicines  as  readily  as 
delicious  viands.  All  the  automatic  movements  unconnected  with  sensation,  of  which  the 
spinal  cord  is  the  instrument,  seemed  to  go-on  without  interference ;  as  did  also  those 
dependent  upon  the  sensations  of  sight  and  touch ;  whilst  the  functions  of  the  other 
ganglia,  together  with  those  of  the  cerebral  hemispheres,  appeared  to  be  in  complete 
abeyance.  The  analysis  of  the  facts  stated  regarding  her  ingestion  of  food  seems  to  make 
this  clear.  She  swallowed  food  when  it  was  put  into  her  mouth;  this  was  a  purely  auto- 
matic action,  the  reception  by  the  lips  being  probably  excited  by  sensation,  whilst  the  act 
of  deglutition,  when  the  food  is  carried  within  reach  of  the  pharyngeal  muscles,  is  excited 
without  the  necessary  concurrence  of  sensation.  She  made  no  spontaneous  effort,  however, 
to  feed  herself  with  the  spoon ;  showing  that  she  had  not  even  that  simple  idea  of  helping 
herself,  which  infants  so  early  acquire.  But  after  the  mother  had  conveyed  the  spoon  a 
few  times  to  her  mouth,  and  had  thus  caused  the  muscular  action  to  become  associated 
with  the  sensorial  stimulus,  the  patient  continued  the  operation.  It  appears,  however,  to 
have  been  necessary  to  repeat  this  lesson  on  every  occasion ;  showing  the  complete  absence 
of  memory  for  any  idea,  even  one  so  simple  and  so  immediately  connected  with  the  supply 
of  the  bodily  wants.  The  difference  between  an  instinct  and  a  desire  or  propensity,  hereto- 
fore dwelt-on  ($§  561,  619),  is  here  most  strikingly  manifested.  This  patient  had  an  instinc- 
tive tendency  to  ingest  food  ;  as  is  shown  by  her  performance  of  the  action  already  alluded- 
to ;  but  these  actions  required  the  stimulus  of  the  present  sensation,  and  do  not  seem  to 
have  been  connected  with  any  notion  of  the  character  of  the  object  as  food;  at  any  rate, 
there  was  no  manifestation  of  the  existence  of  any  such  notion  or  idea,  for  she  displayed  no 
lesire  for  food  or  d.rink  in  the  absence  of  the  objects,  even  when  she  must  have  been  con- 
jcious  of  the  uneasy  sensations  of  hunger  and  thirst.  The  very  limited  nature  of  her 
faculties,  and  the  automatic  life  she  was  leading,  appear  further  evident  from  the  follow- 
ing particulars.  One  of  her  first  acts  on  recovering  from  the  fit,  had  been  to  busy  herself 
in  picking  the  bed-clothes ;  and  as  soon  as  she  was  able  to  sit-up  and  be  dressed,  she  con- 
tinued the  habit  by  incessantly  picking  some  portion  of  her  dress.  She  seemed  to  want 
an  occupation  for  her  fingers,  and  accordingly  part  of  an  old  straw  bonnet  was  given  to 
her,  which  she  pulled  into  pieces  of  great  minuteness  ;  she  was  afterwards  bountifully 
supplied  with  roses ;  she  picked-off  the  leaves,  and  then  tore  them  into  the  smallest 
particles  imaginable.  A  few  days  subsequently,  she  began  forming  upon  the  table,  out  of 
these  minute  particles,  rude  figures  of  roses  and  other  common  garden-flowers;  she  had 
never  received  any  instructions  in  drawing. — Roses  not  being  so  plentiful  in  London,  waste 
Daper  and  a  pair  of  scissors  were  put  into  her  hands ;  and  for  some  days  she  found  an 
occupation  in  cutting  the  paper  into  shreds;  after  a  time  these  cuttings  assumed  rude 
figures  and  shapes,  and  more  particularly  the  shapes  used  in  patchwork.  At  length  she 
was  supplied  with  proper  materials  for  patchwork  ;  and  after  some  initiatory  instruction, 


STATES    OF   EXCLUSIVE    SENSORI-MOTOR   ACTIVITY.  639 

similar  condition  presents  itself  as  the  result  of  the  complete  exhaustion  of  Cere- 
bral power,  in  those  extreme  forms  of  Dementia,  or  rather  Amentia,  which  are 
frequently  consequent  upon  repeated  attacks  of  Mania,  or  a  long  succession  of 
Epileptic  seizures.  And  it  is  also  worth  notice,  that  the  "  picking  at  the  bed- 
clothes," which  is  so  frequently  seen  towards  the  close  of  life,  is  a  purely  con- 
sensual movement,  the  performance  of  which  is  an  indication  of  the  torpor  that 

she  took  to  her  needle  and.  to  this  employment  in  good  earnest.     She  now  laboured  inces- 
santly at  patchwork  from  morning  till  night,  and  on  Sundays  and  week-days,  for  she 
knew  no  difference  of  days  ;  nor  could  she  be  made  to  comprehend  the  difference.     She 
had  no  remembrance  from  day  to  day  of  what  she  had  been  doing  on  the  previous  day, 
and  so  every  morning  commenced  de  novo.     Whatever  she  began,  that  she  continued  to 
work-at  while  daylight  lasted ;    manifesting  no  uneasiness  for  anything  to  eat  or  drink, 
taking  not  the  slightest  heed  of  anything  which  was  going-on  around  her,  but  intent  only 
on    Ler   patchwork.     She  gradually    began,    like  a  child,  to  register   ideas  and  acquire 
experience.     This   was  first   shown   in   connexion  with  her   manual   occupation.     From 
patchwork,  after  having  exhausted  all  the  materials  within  her  reach,  she  was  led  to  the 
higher  art  of  worsted-work,  by  which  her  attention  was  soon  engrossed  as  constantly  as  it 
had  before  been  by  her  humbler  employment.     She  was  delighted  with  the  colours  and  the 
flowers  upon  the  patterns  that  were  brought  to  her,  and  seemed  to  derive  special  enjoyment 
from  the  harmony  of  colours :  nor  did  she  conceal  her  want  of  respect  towards  any  speci- 
men of  work  that  was  placed  before  her,  but  immediately  threw  it  aside  if  the  arrangement 
displeased  her.     She  still  had  no  recollection  from  day  to  day  of  what  she  had  done,  and 
every  morning  began  something  new,  unless  her  unfinished  work  was  placed  before  her ; 
and  after  imitating  the  patterns  of  others,  she  began  devising  some  of  her  own.     The  first 
ideas  derived  from  her  former  experience,  that  seemed  to  be  awakened  within  her,  were 
connected  with  two  subjects  which  had  naturally  made  a  strong  impression  upon  her ; 
namely,  her  fall  into  the  river,  and  a  love-affair.     It  will  be  obvious  that  her  pleasure  in 
the  symmetrical  arrangement  of  patterns,  the  harmony  of  colours,  &c.,  was  at  first  simply 
tensorial ;  but  she  gradually  took  an  interest  in  looking  at  pictures  or  prints,  more  espe- 
cially of  flowers,  trees,  and  animals.     When,  however,  she  was  shown  a  landscape  in  which 
there  was  a  river,  or  the  view  of  a  troubled  sea,  she  became  intensely  excited  and  violently 
agitated,  and  one  of  her  fits  of  spasmodic  rigidity  and  insensibility  immediately  followed. 
If  the  picture  were  removed  before  the  paroxysm  had  subsided,  she  manifested  no  recollec- 
tion of  what  had  taken  place ;  but  so  great  was  the  feeling  of  dread  or  fright  associated 
with  water,  that  the  mere  sight  of  it  in  motion,  its  mere  running  from  one  vessel  to  another, 
made  her  shudder  and  tremble ;   and  in  the  act  of  washing  her  hands  they  were  merely 
placed  in  water.     From  this  it  may  be  inferred  that  simple  ideas  were  now  being  formed ; 
for  whilst  the  actual  sight  or  contact  of  moving  water  excited  them  by  the  direct  sensorial 
channel,  the  sight  of  a  picture  containing  a  river  or  water  in  movement  could  only  do  so 
by  giving  rise  to  the  notion  of  water.     From  an  early  stage  of  her  illness  she  had  derived 
evident  pleasure  from  the  proximity  of  a  young  man,  to  whom  she  had  been  attached ;  he 
was  evidently  an  object  of  interest  when  nothing  else  would  rouse  her ;  and  nothing  seemed 
to  give  her  so  much  pleasure  as  his  presence.     Became  regularly  every  evening  to  see  her, 
and  she  as  regularly  looked  for  his  coming.     At  a  time  when  she  did  not  remember  from 
one  hour  to  another  what  she  was  doing,  she  would  look  anxiously  for  the  opening  of  the 
door  about  the  time  he  was  accustomed  to  pay  her  a  visit ;  and  if  he  came  not,  she  was  fid- 
getty  and  fretful  throughout  the  evening.     When  by  her  removal  into  the  country  she  lost 
sight  of  him  for  some  time,  she  became  unhappy  and  irritable,  manifested  no  pleasure  in 
anything,  and  suffered  very  frequently  from  fits  of  spasmodic  rigidity  and  insensibility. 
When,  on  the  other  hand,  he  remained  constantly  near  her,  she  improved  in  bodily  health, 
early  associations  were  gradually  awakened,  and  her  intellectual  pow'ers  and  memory  of 
words  progressively  returned.     We  here  see  very  clearly  the  composite  nature  of  the  emo- 
tion of  affection.     At  first,  there  was  simple  pleasure  in  the  presence  of  her  lover,  excited 
by  the  gratification  which  the  impress  of  former  associations  had  connected  with  the  sensa- 
tion.    Afterwards,  however,  it  was  evident  that  the  pleasure  became  connected  with  the 
idea  ;  she  thought  of  him  when  absent,  expected  his  return  (even  showing  a  power  of  mea- 
suring time,  when  she  had  no  memory  for  anything  else),  and  manifested  discomfort  if  he 
did  not  make  his  appearance.     Here  we  see  the  true  emotion,  namely,  the  association  of 
pleasure  with  the  idea ;  and  the  manner  in  which  the  desire  would  spring  out  of  it.     The 
desire  in  her  then  condition,  would  be  inoperative  in  causing  voluntary  movement  for  its 
gratification ;  simply  because  there  was  no  intellect  for  it  to  act  upon.     Her  mental  powers, 
however,  were  gradually  returning.     She  took  greater  heed  of  the  objects  by  which  she  was 
surrounded  :  and  on  one  occasion,  seeing  her  mother  in  a  state  of  excessive  agitation  and 
grief,  she  became  excited  herself,  and  in  the  emotional  excitement  of  the  moment  suddenly 
ejaculated,  with  some  hesitation,  "What's  the  matter?"     From  this  time  she  begun  toarti 


640  FUNCTIONS   OF  THE   CEREBRO-SPINAL   NERVOUS   SYSTEM. 

has  supervened  upon  the  functional  activity  of  the  Cerebrum,  and  is,  therefore, 
a  most  unfavourable  symptom. 

715.  Abnormal  Modes  of  Sensori- Motor  Activity. — It  is  the  Sensorium  tha* 
is  primarily,  and  (it  may  be)  solely  affected,  in  the  state  of  Coma  ;  which  only 
differs  from  ordinary  Sleep  in  the  completeness  of  the  suspension  of  the  func- 
tional activity  of  the  Sensory  Ganglia.  This  suspension  not  merely  prevents 
impressions  transmitted  from  the  organs  of  sense,  from  affecting  the  conscious- 
ness as  Sensations;  but  it  also  interposes  the  same  obstacle  to  that  mental  recog- 
nition of  Cerebral  changes,  which,  when  the  Sensorium  is  closed  to  the  outer 
world,  constitutes  the  state  of  Dreaming;  and  thus  the  comatose  subject  is  not 
merely  insensible  to  external  impressions,  but  is  cut-off  from  all  perception  of 
self-existence.  There  seems  reason  to  believe,  that,  in  the  simpler  forms  of  coma, 
such  as  we  frequently  meet-with  in  Hysterical  subjects,  there  is  no  perversion  of 
the  functions  of  the  Cerebrum ;  for  we  observe  that,  if  the  insensibility  sud- 
denly supervene  in  the  midst  of  a  sentence  which  is  being  uttered  by  the  patient 
(a  circumstance  of  no  uncommon  occurrence),  the  series  of  words  is  taken-up  and 
completed  the  moment  that  the  coma  passes-off,  the  patient  being  unconscious  of 
the  interruption ;  showing  that  there  is  none  of  that  confusion  of  the  Intellect, 
which  marks  Cerebral  disorder.  In  a  large  proportion  of  cases,  however,  it  is 
obvious,  from  the  order  in  which  the  symptoms  manifest  themselves,  that  the 
Cerebrum  is  affected,  as  well  as.  the  Sensorial  centres ;  of  this  the  best  evidence 
is  afforded  by  the  phenomena  of  alcoholic  Intoxication,  and  the  agency  of  nar- 
cotic poisons  ]  and  where  Coma  results  from  pressure  within  the  cranium,  this 
must  act  alike  upon  the  Cerebrum  and  the  Sensorium.  Of  the  causes  which 
induce  the  state  of  Coma,  there  are  many  which,  when  operating  in  smaller 

culate  a  few  words  ;  but  she  neither  called  persons  nor  things  by  their  right  names.  The 
pronoun  "this"  was  her  favourite  word;  and  it  was  applied  alike  to  every  individual 
object,  animate  and  inanimate.  The  first  objects  which  she  called  by  their  right  names 
were  wild  flowers,  for  which  she  had  shown  quite  a  passion  when  a  child  ;  and  it  is  remark- 
able, that  her  interest  in  these  and  her  recollection  of  their  names  should  have  manifested 
itself  at  a  time  when  she  exhibited  not  the  least  recollection  of  the  "old  familiar  friends 
and  places"  of  her  childhood.  As  her  intellect  gradually  expanded,  and  her  ideas  became 
more  numerous  and  definite,  they  manifested  themselves  chiefly  in  the  form  of  emotions : 
that  is,  the  chief  indications  of  them  were  through  the  signs  of  emotional  excitement. 
These  last  were  frequently  exhibited,  in  the  attacks  of  insensibility  and  spasmodic  rigidity, 
which  came-on  at  the  slightest  alarm.  It  is  worth  remarking  that  these  attacks,  through- 
out this  remarkable  period,  were  apt  to  recur  three  or  four  times  a  day,  when  her  eyes  had 
Veen  long  directed  intently  upon  her  work;  which  affords  another  proof  how  closely  the 
emotional  cause  of  them  must  have  been  akin  to  the  influence  of  sensory  impressions,  the 
effects  of  the  two  being  precisely  the  same. — The  mode  of  recovery  of  this  patient  was 
quite  as  remarkable  as  anything  in  her  history.  Her  health  and  bodily  strength  seemed 
completely  re-established,  her  vocabulary  was  being  extended,  and  her  mental  capacity 
was  improving;  when  she  became  aware  that  her  lover  was  paying  attention  to  another 
woman.  This  idea  immediately  and  very  naturally  excited  the  emotion  of  jealousy ;  which, 
if  we  analyse  it,  will  appear  to  be  nothing  else  than  a  painful  feeling  connected  with  the 
idea  of  the  faithlessness  of  the  object  beloved.  On  one  occasion  this  feeling  was  so  strongly 
excited,  that  she  fell  down  in  a  fit  of  insensibility,  which  resembled  her  first  attack  in  dura- 
tion and  severity.  This,  however,  proved  sanatory.  When  the  insensibility  passed-off,  she 
was  no  longer  spell-bound.  The  veil  of  oblivion  was  withdrawn ;  and,  as  if  awakening 
from  a  sleep  of  twelve  months'  duration,  she  found  herself  surrounded  by  her  grandfather, 
grandmother,  and  their  familiar  friends  and  acquaintances,  in  the  old  house  at  Shoreham. 
She  awoke  in  the  possession  of  her  natural  faculties  and  former  knowledge ;  but  without 
the  slightest  remembrance  of  anything  which  had  taken  place  in  the  interval,  from  the 
invasion  of  the  first  fit,  up  to  the  present  time.  She  spoke,  but  she  heard  not ;  she  was 
still  deaf,  but  as  she  could  read  and  write  as  formerly,  she  was  no  longer  cut  off  from  com- 
munication with  others.  From  this  time  she  rapidly  improved,  but  for  some  time  conti- 
nued deaf.  She  soon  perfectly  understood  by  the  motion  of  the  lips  what  her  mother  said  ; 
they  conversed  with  facility  and  quickness  together,  but  she  did  not  understand  the  lan- 
guage of  the  lips  of  a  stranger.  She  was  completely  unaware  of  the  change  in  her  lover's 
affections,  which  had  taken  place  in  her  state  of  'second  consciousness;'  and  a  painful 
explanation  was  necessary.  This,  however,  she  bore  very  well,  and  has  since  recovered 
her  previous  bodily  and  mental  health. 


ABNORMAL   MODES    OF   SENSORI-MOTOR    ACTIVITY.  641 

amount,  or  in  less  intensity,  produce  delirium.  This  is  particularly  the  case  with 
the  whole  group  of  truly  narcotic  poisons ;  and  is  true  not  merely  of  those  which 
are  introduced  as  such  from  external  sources,  but  also  with  regard  to  those  which 
are  generated  within  the  body.  We  have  another  illustration  of  it  in  the  Coma 
of  mere  exhaustion,  which  is  frequently  preceded  by  delirium  that  is  clearly  at- 
tributable to  nothing  else  than  a  deficient  supply  of  blood.  Still,  we  must  not 
regard  Coma  as  always  indicating  a  more  advanced  state  of  morbid  change,  than 
that  which  occasions  Delirium  ;  for  it  stands  to  some  forms  of  delirium,  in  the 
same  light  in  which  ordinary  sleep  stands  to  the  waking  state,  being  the  repose 
which  is  required  for  reparation  after  a  state  of  excessive  mental  activity.  In  fact, 
the  profound  sleep  which  succeeds  a  protracted  period-  of  severe  bodily  or  mental 
exertion,  is  often  almost  comatose,  as  regards  the.  degree  in  which  the  subject  of 
it  is  insensible  to  external  stimuli.  The  same  may  be  stated  with  great  probability 
of  the  coma  which  is  consequent  upon  l  concussion '  of  the  brain ;  for  this  may 
be  regarded  as  a  period  of  slow  regeneration,  during  which  the  effects  of  the 
injury  are  being  repaired  by  the  nutritive  processes ;  and  any  attempt  to  arouse  the 
patient  prematurely  is  far  more  likely  to  be  injurious  than  beneficial,  tending  espe- 
cially to  increase  the  violence  of  the  subsequent  reaction.  This  state,  in  fact,  is 
essentially  one  of  Syncope;  the  suspension  or  reduction  of  the  functional  power 
of  the  Encephalic  centres  being  mainly  due  to  deficiency  in  the  supply  of  blood 
which  they  receive,  through  the  depression  produced  by  the  '  shock'  in  the  action 
of  the  Heart  (§  238). 

716.  A  state  of  disordered  activity  of  the  Sensorial  centres  appears  to  be  the 
essential  cause  of  the  production  of  those  illusions  (most  commonly  visual,  but 
not  unfrequently  belonging  to  some  other  sense),  the  origin  of  which  is  entirely 
independent  of  any  ideational  or  emotional  state,  and  in  the  reality  of  which  the 
mind  has  no  predisposition  to  believe  (§  711).     The  disordered  action  of  the 
Sensational  apparatus  seems  to  be  of  the  same  kind  with  that  which  produces 
*  subjective  sensations '  (§  597),  extending  only  to  the  affection  of  the  Percep- 
tional consciousness;  for  it  is,  in  fact,  nothing  else  than  the  recognition  of  the 
apparent  externality  of  the  objects  which  thus  affect  the  consciousness, — generally 
arising  from  their  resemblance  to  well-known  forms,  voices,  articulate  sounds, 
&c., — that  distinguishes  i  phantasms  ;  or  (  airy  voices  '  from  the  subjective  sensa- 
tions on  which  they  depend     These  may  deceive  the  mind,  from  their  close 
resemblance  to  realities ;   thus  Dr.  Abercrombie  mentions  a  case  of  a  gentleman 
who  had  all  his  life  been  affected  by  the  appearance  of  spectral  figures,  which  so 
closely  resembled  the  impressions  produced  by  the  real  objects,  that,  on  meeting 
a  friend  in  the  street,  he  could  not  satisfy  himself  whether  he  saw  the  real  indi- 
vidual or  the  spectral  figure,  save  by  touching  his  body,  or  by  hearing  the  sound 
of  his  footsteps.     But  in  most  instances  in  which  they  have  not  been  suggested 
by  antecedent  mental  states  their  appearance  takes  place  under  such  circum- 
stances, that  even  though  they  may  produce  reflex  muscular  actions  (§  599),  the 
Intelligence  is  readily  enabled  to  discriminate  the  false  from  the  true.     This  was 
the   case,  for  example,  with  Nicolai;  who,  when    suffering  from  intermittent 
fever,  saw  coloured  pictures  of  landscapes,  trees,  and  rocks,  resembling  framed 
paintings,  but  of  half  the  natural  size;  so  long  as  he  kept  his  eyes  closed,  they 
underwent  constant  changes,  some  figures  disappeared  while  new  ones  showed 
themselves  ;  but  as  soon  as  he  opened  his  eyes,  the  whole  vanished.    In  the  case 
previously  adverted-to,  the  subject  of  these  illusions  could  call-up  spectral  figures 
at  his  will,  by  directing  his  attention  steadily  to  some  conception  of  his  own 
mind,  which  might  either  consist  of  a  figure  or  a  scene  that  he  had  seen,  or 
might  be  a  composition  of  his  own  imagination  :  but  although  possessing  the 
faculty  of  producing  the  illusion,  he  had  no  power  of  banishing  it;  so  that  when 
he  had  called-up  any  particular  figure  or  scene,  he  could  n^t  say  how  long  it 
might  continue  to  haunt  him.     This  influence  of  the  attention  was  noticed  by 
Sir  Isaac  Newton  in  his  investigation  of  ocular  spectra ;  fur  he  found  that  ho 
41 


642  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

could  recall  the  spectrum  of  the  sun  after  it  had  vanished,  by  going  into  the 
dark,  and  directing  his  mind  intensely  "  as  when  a  man  looks  earnestly  to  see  a 
thing  which  is  difficult  to  be  seen."  By  repeating  these  experiments  frequently, 
such  an  effect  was  produced  upon  his  Sensorium,  that  for  some  months,  he 
says,  "  the  spectrum  of  the  sun  began  to  return,  as  often  as  I  began  to  meditate 
on  the  phenomena,  even  though  I  lay  in  bed  at  midnight  with  my  curtains 
drawn/"  The  essentially-automatic  character  of  these  false  preceptions,  however, 
is  evident  from  the  influence  of  toxic  agents,  such  as  opium,  hachisch,  or  alcohol, 
fever-poison,  &c.,  in  producing  them.  That  the  mind  of  the  individual  thus 
affected  should  believe  in  them  as  realities,  simply  results  from  the  circumstance, 
that,  concurrently  with  the  disorder  of  the  Sensorium,  the  Cerebrum  is  also 
affected,  so  that  its  Intelligence  is  not  in  a  fit  state  to  correct  the  erroneous  sug- 
gestions of  the  Senses. 

717.  It  is,  as  we  have  seen,  in  the  Sensorial  centres,  that  those  lesions  are 
most  commonly  found,  which  give  rise  to  Hemiplegic  Paralysis.     There  can  be 
little  doubt  that  this  form  of  paralysis  is  usually  attributable  to  some  structural 
disorganization  of  the  nervous  substance,  produced  by  haemorrhage,  softening,  &c. 
Still,  this,  like  other  forms  of  partial  paralysis,  may  be  toxic,  depending  rather 
upon  the  condition  of  the  blood,  than  upon  that  of  the  nervous  tissue.     Of  such 
toxic  influence,  we  have  a  remarkable  example  in  the  peculiar  local  paralysis 
induced  by  the  presence  of  Lead  in  the  system ;  and  there  seems  much  reason 
to  believe  that  some  of  the  Hysterical  forms  of  paralysis  (as  well  as  of  convul- 
sive disorders)  are  of  toxic  origin  (§723).     There  are  many  instances,  too,  in 
which  paralysis,  like  convulsion,  seems  to  depend  upon  some  injurious  influence 
propagated  from  the  nerves  of  some  other  part.     Although  it  is  in   Plemiplegia 
that  we  have  the  most  distinct  evidence  of  disorder  of  the  Encephalic  centres, 
yet  paralysis  of  any  one  part  of  the  body  may  proceed  from  Encephalic  lesion ;  and 
even  some  forms  of  Paraplegia  seem  traceable  to  disorders  of  the  Cerebrum  and 
Sensory  Ganglia.2 — It  is  to  a  disturbance  in  the  equilibrium  of  the   Sensori- 
Motor   apparatus,  consequent   in   some   instances   upon    abnormal   impressions 
received  through  the  nerves  of  sense,  and  in  others  upon  interruption  to  some  of 
the  ordinary  channels  of  motor  influence,  that  Vertiyo  is  due  ;3  which  may  either 
consist  in  abnormal  subjective  sensations  only,  or  may  exhibit  disordered  move- 
ments prompted  by  those  sensations.     This  condition  may  be  induced  by  certain 
lesions  of  the  Sensori-Motor  centres  or  of  the  Sensory  Nerves  (§§  530-534);  or 
it  may  depend  upon  the  presence  of  certain  toxic  agents  in  the  blood  (as  in 
Alcholic  intoxication),  or  it  may  proceed  from  a  mere  deficiency  in  the  supply  of 
blood  to  the  Sensori-motor  apparatus. 

718.  We  seem  entitled  to  consider  the  Sensory  Ganglia  as  the  primary  seat  of 
that  combination  of  loss  of  sensibility  with  convulsive  movements,  which  essen- 
tially constitutes  Epilepsy.  This  is  marked  by  the  peculiar  sensorial  phenomena 
which  usually  precede  the  paroxysm ;  by  the  obliteration  of  consciousness,  which 
is  its  prominent  symptom ;  and  by  the  peculiarity  of  the  spasmodic  contractions, 
which  are  clonic  (or  alternating  with  relaxation)  instead  of  being  tonic  (or  persis- 
tent), and  which  correspond  with  those  that  may  be  induced  by  artificial  stimu- 
lation of  this  portion  of  the  Encephalic  centres  (§  535).  The  disordered  action, 
however,  manifestly  extends  itself  to  the  Cerebrum  ;  for  a  maniacal  paroxysm 
frequently  occurs  in  connection  with  the  epileptic  attacks;  the  attacks  them- 

1  A  large  number  of  interesting  cases  of  Spectral  Illusions  will  be  found  in  Dr.  Aber- 
oombie's  "Inquiry  concerning  the  Intellectual  Powers,"  under  the  head  of  'Perception' 
i»nd  'Spectral   Illusions.'     See  also  Sir  B.  Brodie's  "Psychological  Enquiries,"  and  the 
Essay  of  M.  Baillarger  already  referred-to. 

2  For  much  valuable  information  on  the  different   forms  of  Paralysis,  see  Dr.  Gull's 
Gulstonian  Lectures  'On  the  Nervous  System'  in  the  "Medical  Times,"  1849. 

3  For  a  summary  of  what  is  known  as  to  the  nature  of  this  affection,  with  valuable  sug- 
gestions for  further  enquiry,  See  Dr.  J.  Russell  Reynold's  "Essay  on  Vertigo,"  read  to  the 
North  London  Medical  Society,  1854. 


ABNORMAL   MODES    OF    SENSORI-MOTOR   ACTIVITY. — EPILEPSY.      643 

selves  are  sometimes  preceded,   and  very  commonly  followed,  by  considerable 
confusion  of  the  intellect;  the  disease  is  seldom  long  persistent  without  impair- 
ing the  memory  and  the  control  of  the  will  over  the  mental  operations;  and  in 
cases  of  long  standing,  the  power  of  the  Cerebrum  appears  to  be  almost  entirely 
destroyed.     There  is  very  considerable  diversity,  on  the  other  hand,  in  regard  toj 
the  nature  and  intensity  of  the  muscular  convulsion  ;  and  there  seems  reason  to 
think  that  when  the  morbid  influence  is  determined  downwards  into  the  Motor 
apparatus,  the  Cerebrum  escapes  with  a  less  serious  impairment  of  its  powers, 
since  the  destruction  of  the  intellectual  power  occurs  more  surely  where  the  fits 
are  accompanied  by  much  mental  disturbance  or  stupor,  than  where  the  convul- 
sive   character   predominates. — One   of   the    most    remarkable    phenomena   of 
Epilepsy  is  its  tendency  to  periodic  recurrence,  with  a  more  or  less  complete 
return  to  the  normal  state  in  the  interval.     This  fact  of  itself  seems  to  indicate 
that  the  disease  cannot  be  fairly  attributed  to  those  obvious  lesions  of  structure, 
which   are  sometimes  coincident  with  it,   and   which,  as  Dr.  Todd  has   justly 
remarked,  are  rather  the  signs  of  the  altered  nutrition  brought-on  by  any  cause 
which  creates  frequent  disturbance  of  the  actions  of  the  brain,  than  the  causes  of 
that  disturbance ;  for  the  influence  of  such  lesions,  if  manifested  at  all  (and  it  is 
remarkable  what  an  extent  of  disorganization  may  take  place  without  any  obvi- 
ous indication),  would  be  rather  continuous  than  intermitting.     It  is  quite  cer- 
tain, on  the  other  hand,  that  death  may  occur  from  Epilepsy,  without  any  appre- 
ciable lesion.     It  may  be  considered,  also,  as  a  well-established  fact,  that  the 
epileptic  paroxysm  may  be  induced  either  by  an  insufficient  supply,  or  by  depra- 
vation of  blood  ;  of  this  we  have  examples  in  the  epileptiform  convulsions  brought- 
on  by  excessive  haemorrhage  in  parturient  women,  in  the  epileptiform  paroxysm 
induced  by  asphyxia  (especially  by  strangulation),  and  in  poisoning  by  hydrocy- 
anic acid,  the  phenomena  of  which,  in  the  lower  animals  especially,  so  closely 
simulate  those  of  the  genuine  disease,  that  they  may  be  designated  as  an  artificial 
epilepsy.     These  and  many  other  facts  in  the   etiology  of  the    disease,  very 
strongly  point  to  a  disordered  condition  of  the  blood  as  its  primal  source ;  this 
acting  either  by  altering  the  nutrition  of  the  Encephalic  centres,  or  by  pervert- 
ing their  action,  or  in  both  modes  conjointly,  as  in  the  case  of  Insanity  (§  705). 
According  to  the  theory  advocated  by  Dr.  Todd,  a  continual  mal-nutrition  of 
certain  parts  of  the  Encephalon  occasions  a  gradually-increasing  disturbance  of 
their  polar  state ;  and  this,  when  it  has  attained  a  certain  measure  of  intensity, 
manifests  itself  in  the  epileptic  paroxysm,  just  as  a  Leyden  jar,  when  charged 
with  electricity  to  a  certain  state  of  tension,  gets  rid  of  the  disturbance  of  equi- 
librium by  the  "  disruptive  discharge."1     The  fact  must  not  be  disregarded,  how- 
ever, that  when  a  state  of  mal-nutrition  of  the  Nervous  System  has  been  estab- 
lished by  causes  which  affect  the  condition  of  the  Blood,  the  epileptic  paroxysm 
may  be  induced  by  some  eccentric  or  peripheral  irritation,  such  as  worms  in  the 
intestinal  canal,  the  pressure  of  teeth  in  the  eruptive  stage  of  development  against 
the  capsule  or  the  gum,  &c. ;  neither  cause  being  sufficient  when  acting  alone 
Hence,  although  the  paroxysms  may  be  suspended,  and  the  disease  apparently 
cured,  by  the  removal  of  the  peripheral  source  of  irritation,  (as  by  the  expulsion 
of  the  worms  or  the  complete  eruption  of  the  teeth),  the  liability  to  it  still 
remains,  as  is  shown  by  the  renewal  of  the  paroxysms  whenever  any  fresh  irrita- 
tion may  arise.     It  is  very  important,  therefore,  not  to  rest  satisfied  with  local 
treatment  in  such  cases ;  but  to  have  recourse  to  measures  adapted  to  produce  a 
general  invigoration  of  the  system.2 

1  See  Dr.  Todd's  'Lumleian  Lectures'  in  the  "Medical  Gazette,"  May  18,  1849;  and 
the  "Brit,  and  For.  Med.-Chir.  Rev.,"  Jan.,  1850,  pp.  24-33. 

3  The  Author  does  not  think  it  necessary  here  to  devote  any  space  to  the  examination 
of  Dr.  M.  Hall's  pathological  theory  of  Epilepsy,  which  makes  it  depend  upon  spasmodic 
compression  of  certain  muscles  of  the  neck,  producing  compression  of  the  veins  and  con- 
gestion of  the  cerebrum ;  since  he  considers  that  the  fallacies  of  this  theory  have  been 
already  sufficiently  pointed-out  by  Dr.  Todd  (loc.  cit.J 


644  FUNCTIONS    OF   THE    CEREBRO-SPINAL   NERVOUS    SYSTEM. 

710.  The  Spinal  Axis  (including  the  Medulla  OUcmgata}  forms  a  continuous 
series  of  ganglionic  centres,  which  are  connected  by  afferent  and  efferent  nerve- 
trunks  with  the  several  segments  of  the  body;  but  these  centres  are  enveloped 
in  white  or  fibrous  strands,  which  not  only  connect  the  various  segmental  divi- 
sions with  each  other,  but  also,  there  seems  good  reason  to  believe,  establish  a 
continuous  connection  between  the  Nerve-roots  and  the  Sensorial  centres.     The 
independent  activity  of  the  Spinal  centres  is  seen  in  the  various  reflex  movements 
which  are  performed  after  they  have  been  cut-off  from  all  connection  with  the 
Kncephalon;  and  of  these  reflex  movements  there  are   certain   definite   groups, v 
which  are  subservient  to  the  functions  of  Respiration,  Deglutition,  Defecation, 
£c.     In  so  far  as  these  are  performed  by  the  Spinal  Cord  alone,  without  the  par- 
ticipation of  the  Sensorium,  they  do  not  involve  any  affection  of  the  conscious- 
ness ;  and  as  the  separation  of  the  Spinal  Cord  from  the  Sensorium  effectually 
prevents  the  impression  which  excites  the  reflex  movement  from  exciting  sensa- 
tion at  the  same  time,  we  know  that  sensation  cannot  be  necessary  to  the  move- 
ment }  hence  this  class  of  actions  is  best  distinguished  as  excito-motor,  in  contra- 
distinction   to    the    sensori-motor   in  which    Sensation    necessarily  participates. 
Putting  aside,  however,  those  actions  which  are  subservient  to  the  Organic  func- 
tions, and  which  are  performed  in  the  state  of  full  integrity  and  activity  of  the 
nervous  system,  we  find  that  the  reflex  power  of  the  Spinal  Cord  is  only  distinctly 
manifested  when  that  organ  is  detached  from  the  Encephalon ;  for  in  its  normal 
state  it  serves  as  little  else  than  the  channel  through  which  impressions  are  trans- 
mitted upwards  to  the  Sensorium,  and  thence  to  the  Cerebrum,  and  through 
which  motor  impulses  are  propagated  downwards  from  these  centres  to  the  mus- 
cles.    For  the  actions  of  the  Spinal  Cord  are  placed  in  subordination  to  the 
control  of  the  Cerebrum,  in  every  particular  as  to  which  they  can  be,  without 
detriment  to  the  welfare  of  the  system  generally ;  so  that  we  find  excitor  impres- 
sions, which  are  quite  competent  to  evoke  reflex  actions  if  they  are  prevented 
from  travelling  beyond  the  Cord,  losing  their  power  to  do  so  when  they  are  dis- 
charged (so  to  speak)  into  the  Sensorium ;  whilst  even  the  movements  of  Respi- 
ration, Defecation,  &c.,  which  do  not  require  the  participation  of  the  Cerebrum  in 
their  ordinary  performance,  can  be  to  a  certain  extent  controlled  by  the  Will. 

720.  Abnormal  Actions  of  the  Spinal  Oord. — The  functional  activity  of  the 
Spinal  Cord  is  capable  of  being  morbidly  diminished  or  augmented.  It  may 
even  be  for  a  time  almost  completely  suspended,  as  in  Syncope  (§  715) :  but  it 
would  seem  as  if  a  supply  of  blood  which  is  insufficient  to  support  the  activity 
of  the  Encephalic  centres,  might  still  sustain  (to  a  certain  extent)  the  functional 
power  of  the  Spinal  system  j  for  we  find  the  respiratory  movements  and  the  power 
of  swallowing  to  be  the  last  to  cease  when  the  Heart's  action  is  failing,  and  the 
first  to  return  when  it  is  becoming  more  vigorous.  A  corresponding  state  may 
be  induced  in  particular  portions  of  the  system,  by  Concussion ;  as  is  seen  in 
severe  shocks  to  the  Spinal  Cord,  which  are  almost  invariably  followed  for  a  time 
by  the  suspension  of  its  functions.  Again  the  power  of  the  whole  Spinal  Cord 
may  be  diminished  by  various  causes,  such  as  enfeebled  circulation,  pressure,  &c.; 
and  then  we  have  torpidity  and  imperfect  nutrition  of  the  whole  muscular  sys- 
tem (§  358  note).  If  oppression  exist  in  the  Brain,  the  functions  of  the  Medulla 
Oblongata  will  be  especially  affected  ;  and  if  it  be  prolonged  and  sufficiently  severe, 
Asphyxia  will  result  from  the  interruption  of  the  respiratory  movements  which  it 
occasions  (§  326) ;  this,  in  fact,  being  the  mode  in  which  death  is  immediately 
produced  in  Narcotic  Poisoning  and  other  analogous  states  (Chap.  xix).  In  the 
Convulsive  diseases  to  be  presently  noticed,  the  fatal  result  is  usually  consequent 
upon  a  state  of  Asphyxia  produced  by  the  spasmodic  fixation  of  the  respiratory 
muscles. 

721.  On  the  other  hand,. the  excitability  of  the  whole  Cord,  or  of  particular 
parts  of  it,  may  be  morbidly  increased ;  as  is  the  case  in  the  various  classes  of 
Convulsive  diseases  in  which  the  consciousness  is  not  affected.  Of  the  distinct 


ABNORMAL   ACTIONS    OF   SPINAL    CORD: — HYSTERIA.  645 

forms  or  combinations  of  which  this  class  of  disorders  is  composed,  Tetanus  is 
one  of  the  most  interesting  and  instructive.  This  disease  essentially  consists  in 
an  undue  excitability  of  the  whole^series  of  Spinal  Ganglia;  so  that  very  slight 
impressions  produce  violent  and  extensive  reflex  actions,  the  disturbance  of 
nervous  polarity  induced  by  the  impression,  radiating  (as  it  were)  through  the 
whole  Cord,  and  affecting  nerve-fibres  that  proceed  from  each  of  its  different 
segments;  and  when  this  state  is  fully  established,  convulsive  actions  may  pro- 
ceed from  purely  centric  irritation,  no  excitor  impression  being  required  to 
originate  them.  Such  a  state  may  be  induced  by  various  causes,  among  the 
most  prominent  of  which  are,  on  the  one  hand,  those  which  affect  the  nutrition 
of  the  Cord,  and,  on  the  other,  those  which  call  it  into  disordered  action,  by 
altering  the  relations  which  the  blood  bears  to  it  as  the  exciting  fluid  of  the 
nervous  battery.  That  which  is  termed  the  idiopathic  form  of  the  disease  seems 
traceable  to  mal-nutrition  of  the  Cord,  consequent  upon  impoverishment  or 
depravation  of  the  blood;  that,  on  the  other  hand,  which  is  produced  by  the 
introduction  of  Strychnia  into  the  blood,  is  dependent  upon  the  peculiar  potency 
of  this  substance  in  determining  a  wrong  action  of  the  Spinal  centres,  for  which 
it  seems  to  have  an  elective  affinity,  in  the  same  way  that  alcohol  and  opium  have 
for  the  encephalic.  With  regard  to  the  traumatic  form  of  Tetanus,  it  is  impos- 
sible to  say  with  certainty  whether  the  peculiar  condition  of  the  Spinal  Cord  be 
determined,  as  in  the  preceding  case,  by  the  introduction  of  a  poison  into  the 
blood,  through  some  morbid  action  taking  place  in  the  wound ,  or  whether  the 
disturbance  of  the  usual  equilibrium  be  consequent  upon  the  propagation  of  a 
morbid  influence  directly  from  the  injured  nerve-trunk  to  the  Spinal  centres, 
without  any  participation  of  the  circulating  System  in  this  extension  of  the  mis- 
chief. Whichever  be  the  true  account  of  it,  this  much  is  certain,  that  when  the 
Tetanic  state  of  the  Spinal  Cord  is  once  fully  established,  nothing  is  gained  by 
removal  of  the  injured  part ;  and  powerful  sedative  remedies  alone  possess  any 
influence  in  restraining  the  paroxysms.  The  Cerebral  apparatus  is  entirely 
unaffected  in  this  disorder;  but  the  nerves  of  deglutition  are  usually  those  first 
influenced  by  it ;  those  of  respiration,  however,  being  soon  affected,  as  also  those 
of  the  trunk  in  general. 

722.  The  condition  termed  Hydrophobia  is  nearly  allied  to  that  of  traumatic 
Tetanus,  differing  chiefly  in  the  mode  in  which  the  Cranio-spinal  axis  is  affected. 
The  irritable  state  of  the  nervous  centres  obviously  results  from  the  introduction 
of  a  poison  into  the  blood;   and  here  the  early  removal  of  the  wounded  part  is 
very  desirable  as  a  means  of  prevention ;   although,  when  the  poison  has  once 
begun  to  operate  on  the  centres,  it  is  of  no  use.     The  muscles  of  respiration  and 
deglutition  are,  as  in  Tetanus,  those  spasmodically  affected  in  the  first  instance  j 
but  there  is  this  curious  difference  in  the  mode  in  which  they  are  excited  to 
action, — that,  whilst  in  Tetanus  the  stimulus  operates  through  the  Spinal  Cord 
(either  centrally,  or  by  being  conveyed  from  the  periphery),  in  Hydrophobia  it 
is  often  transmitted  from  the  ganglia  of  Special  Sense,  or  even  from  the  Cere- 
brum ;  so  that  the  sight  or  sound  of  fluids,  or  even  the  idea  of  them,  occasions — 
equally  with  their  contact,  or  with  that  of  a  current  of  air — the  most  distressing 
convulsions. 

723.  Many  forms  of  that  protean  malady,  Hysteria,  are  attended  with  a  similar 
irritability  of  the  Nervous  Centres;  but  there  is  this  remarkable  difference  in  the 
two  cases,  that  the  morbid  phenomena  of  Hysteria,  whilst  they  often  simulate 
those  of  Chorea,  Tetanus,  Hydrophobia,  Epilepsy,  &c.,  are  evidently  dependent 
upon  a  state  of  the  system  of  a  much  less  abnormal  character.     The  absence  of 
any  structural  lesion,  and  even  of  any  serious  impairment  of  the  nutrition,  of  the 
parts  of  the  Nervous  System  which  are  the  sources  of  the  actions  in  question,  is 
proved  by  the  length  of  time  during  which  the  severest  forms  of  them  may  exist 
without  permanently-serious  consequences,  and  by  the  suddenness  with  which  the 
several  forms  of  them  give  place  one  to  another,  or  pass-off  altogether.     Th* 


646  FUNCTIONS   OF   THE    CEREBRO-SPINAL   NERVOUS   SYSTEM. 

strange  combinations,  moreover,  which  they  occasionally  present,  remarkably 
distinguish  them  from  the  more  settled  forms  of  the  diseases  which  they  simu- 
late.1 The  clinical  history  of  Hysteria,  then,  would  lead  us  to  suppose  that  the 
convulsive  action  depends  rather  upon  some*  state  of  the  blood  which  alters  its 
relation  to  the  nervous  tissue  as  its  exciting  fluid,  than  upon  any  such  change  in 
the  nutritive  supply  which  it  affords,  as  would  induce  a  more  permanent  disorder 
in  the  system.  Taking  all  the  phenomena,  however,  into  account,  there  seems 
much  reason  to  think  that  a  general  excitability  of  the  nervous  system,  such  as 
is  only  an  exaggeration  of  that  which  is  characteristic  of  the  female  sex,  is  induced 
by  some  defect  of  Nutrition,  comparatively  permanent  in  its  nature ;  whilst  the 
particular  forms  of  perverted  action  are  determined  either  by  some  toxic  agent  in 
the  blood,  slight  variations  in  which  may  give  it  a  selective  power  for  one  part  or 
another  of  the  Nervous  Centres,  or  by  irritation  of  the  peripheral  nerves.  Among 
the  sources  of  imperfect  nutrition,  leading  to  undue  excitability  of  the  nervous 
system,  and  thus  acting  as  a  '  predisposing  cause/  it  seems  probable  that  a  gouty 
diathesis  is  one  of  the  most  frequent;2  whilst  among  the  'exciting  causes/  some 
irregular  action  of  the  sexual  apparatus  is  among  the  most  common,  though  it 
would  not  be  correct  to  affirm,  that  disorder  of  the  nutritive  or  secretory  functions 
of  the  sexual  system  is  essential  to  the  production  of  the  hysteric  condition.  The 
influence  of  Emotional  states  upon  this  condition  (§  710),  is  among  the  most 
remarkable  features  in  the  history  of  the  disorder.  There  can  be  little  doubt 
that  habitual  indulgence  of  the  feelings,  especially  when  these  are  of  a  painful 
kind,  has  a  direct  tendency  to  affect  the  nutrition  of  the  nervous  system ;  but 

1  Thus,  the  Author  has  known  an  obstinate  case  of  Hysteric  disorder,  in  which  at  one 
period  attacks  of  the  most  complete  Opisthotonos  coexisted  with  perfect  Coma ;  at  another 
period,  the  Coma  recurred  alone;  then,  again,  there  was  Trismus,  lasting  for  five  consecu- 
tive days,  without  any  other  spasmodic  action  or  loss  of  sensibility  ;  this  sometimes  alter- 
nated with  fits  of  Yawning,  in  which  the  jaw  was  held  open  for  half  an  hour  together  ;  at 
another  period,  the  convulsions  had  more  of  the  Epileptic  character,  the  face  being  dis- 
torted, and  the  limbs  agitated,  concurrently  with  a  state  of  Coma,  but  without  laryngismus; 
with  this  alternated  fits  of  Laryngismus,  without  insensibility,  and  occurring  during  the 
expiratory  movement;  whilst  during  the  whole  of  this  succession,  there  was  Paralysis  of 
the  extensor  muscles  of  both  lower  extremities,  with  paroxysms  of  the  most  violent  and 
prolonged  Cramp  in  one  of  them.  The  mental  phenomena  of  this  case  were  almost  equally 
strange ;  for  a  state  of  almost  Maniacal  excitement  often  catne-on  suddenly,  and  ceased  no 
less  abruptly ;  and  every  form  of  Double  Consciousness,  from  simple  sleep-waking  to  an 
alternation  of  two  very  similar  states  of  mental  existence,  presented  itself  during  one  long 
period  of  the  disorder. — It  is  worth  noting  that  in  this  case  the  exciting  cause  of  the  dis- 
order lay  in  the  disappointment  of  affections  long  cherished  in  secret;  but  the  nutrition 
of  the  nervous  system  had  been  previously  impaired  by  anxiety  and  excessive  mental 
exertion.  The  first  access  of  the  disorder  was  kept-off  by  the  influence  of  a  very  deter- 
mined will ;  but  when  the  malady  had  fully  developed  itself,  it  resisted  every  kind  of 
treatment  for  four  years.  The  catamenial  discharge  remained  very  scanty  during  the 
whole  of  that  time,  and  was  sometimes  absent  altogether ;  and  the  recurrence  of  the  period 
was  almost  invariably  marked  by  an  aggravation  of  the  spasmodic  attacks,  and  frequently 
by  pains  resembling  those  of  the  first  stage  of  labour.  A  slow  and  almost  imperceptible 
improvement  was  taking-place,  when  circumstances  occurred  which  gave  a  new  turn  to  the 
feelings ;  a  fresh  attachment  was  formed,  which  was  happily  reciprocated ;  and  from  that 
time  the  cure  rapidly  advanced,  the  convulsive  and  paraplegic  affections  being  speedily 
recovered-from,  and  nothing  being  left  but  dysmenorrhcea,  which  still  continued  to  be 
occasionally  accompanied  by  severe  cramps,  and  sometimes  by  general  convulsion,  coma, 
&c.  This  was  not  altogether  corrected,  though  improved,  by  marriage ;  and  any  emo- 
tional excitement  of  an  unpleasant  kind  was  sure  to  produce  an  additional  aggravation. 
The  state  of  the  os  uteri  was  then  examined;  and  as  it  was  found  to  be  unduly  contracted, 
cautious  dilatation  by  sponge-tents  was  practised.  This  had  the  best  results ;  the  dysme- 
norrhoea  soon  abated ;  pregnancy  supervened,  and  after  a  miscarriage  (which  seemed 
traceable  to  emotional  excitement,  coinciding  with  the  monthly  nisus)  a  second  pregnancy 
followed,  which  went-on  to  the  full  term ;  and  no  return  of  the  spasmodic  attacks  has 
since  occurred. — It  is  worthy  of  note  that  in  this  case  there  was  an  hereditary  predispo- 
sition to  Gout,  which  seemed  once  to  manifest  itself  in  a  peculiar  affection  of  the  tissues 
*bout  the  wrist-joint,  of  a  character  rather  gouty  than  rheumatic. 

'  See  Dr.  Laycock  "On  the  Nervous  Diseases  of  Women,"  pp.  161,  et  seq. 


ABNORMAL    ACTIONS    OF    SPINAL    CORD.  647 

when  these  feelings  have  special  reference  to  sexual  subjects,  they  will  exert  a 
powerful  indirect  influence,  by  fixing  the  mind  on  the  genital  system,  and  thereby 
modifying  its  condition  (CHAP.  xv.). — Hence  the  treatment  of  Hysteria  may  be 
considered  as  requiring  three  classes  of  remedial  means ; — those,  namely,  which 
operate  by  improving  the  general  state  of  nutrition  of  the  Nervous  System,  and 
by  diminishing  its  excitability,  these  for  the  most  part  acting  through  the  blood, 
and  being  directed  to  the  increase  of  its  nutritive  components  and  to  the  elimi- 
nation of  any  morbid  matter  which  it  may  be  suspected  to  contain  ;  those,  secondly, 
which  operate  by  removing  the  exciting  causes  of  the  paroxysm,  among  which  may 
be  specially  reckoned  all  such  as  promote  the  healthful  performance  of  the  men- 
strual function  ;  and  lastly,  all  those  which  act  beneficially  on  the  Mind,  divert- 
ing or  repressing  painful  emotions,  or  substituting  pleasurable  feelings  in  their 
place,  and  strengthening  the  general  control  of  the  Will. 

724.  The  foregoing  are  the  chief  Convulsive  diseases,  in  which  the  Spinal 
centres  generally  are  involved;  but  there  are  many  spasmodic  affections  of  a 
more  limited  character,  which  are  traceable  to  a  morbid  affection  of  some  parti- 
cular division  of  the  Spinal  Axis.  Thus  in  the  various  forms  of  Spasmodic 
Asthma,  the  Medulla  Oblongata  would  seem  to  be  alone  involved ;  the  attacks 
of  this  disorder  usually  resulting  from  some  internal  irritation,  either  in  the  air- 
passages  themselves,  or  in  the  digestive  system,  producing  a  reflex  contraction 
of  the  muscular  fibres  of  the  bronchial  tubes  (§  291).  In  the  purely  spasmodic 
stage  of  Hooping -Cough,  again,  which  frequently  persists  long  after  all  inflam- 
matory symptoms  have  subsided,  we  have  another  example  of  spasmodic  action 
limited  to  the  respiratory  centres;  and  here  we  find  distinct  evidence  that  the 
morbid  condition  originates  in  the  introduction  of  a  poison  into  the  blood.  The 
same  may  be  said  of  the  Croup-like  Convulsion  or  Crowing  Inspiration  of 
Infants,  which  is  an  obstruction  to  the  passage  of  air  through  the  Glottis,  pro- 
duced by  a  spasmodic  contraction  of  the  constrictors  of  the  larynx;  for  although 
the  spasmodic  action  may  be  immediately  brought-on  by  various  kinds  of  local 
irritation,  such  as  that  occasioned  by  teething,  by  the  presence  of  undigested  food, 
or  by  intestinal  disorder,  yet  there  is  no  doubt  that  the  excitable  condition  of  the 
Nervous  Centres,  without  which  these  influences  would  be  inoperative,  is  depend- 
ent upon  a  defect  of  nutrition  arising  from  unwholesome  food,  bad  air,  or  some 
other  cause  affecting  the  system  generally.1 — Spasmodic  closure  of  the  Larynx 
may  occur  from  other  causes.  When  the  rima  glottidis  is  narrowed,  by  effusion 
of  fluid  into  the  substance  of  its  walls,  it  is  very  liable  to  be  completely  closed  by 
spasmodic  action,  to  which  the  unduly-irritable  condition  of  the  mucous  mem- 
brane will  furnish  many  sources  of  excitement.  Choking,  again,  does  not  result 
so  much  from  the  pressure  of  the  food  on  the  air-passages  themselves,  as  from 
the  spasmodic  action  of  the  larynx  excited  by  this ;  and  the  dislodgment  of  the 
morsel  by  an  act  of  vomiting,  is  the  most  effectual  means  of  obtaining  relief. — 
Tenesmus  and  Strangury  are  well-known  forms  of  spasmodic  muscular  con- 
traction, excited  by  local  irritation  acting  through  the  Spinal  centres.  The 
abnormal  action  which  leads  to  Abortion  (CHAP.  XVI.)  is  frequently  excited  in 
the  same  manner. — There  is  a  form  of  Incontinence  of  Urine,  which  is  very 
analogous  to  the  morbid  action  just  described;  the  sphincter  has  its  due  power; 
but  the  stimulus  to  the  evacuation  of  the  bladder  is  excessive  in  strength  and 
degree,  owing  to  the  acridity  of  the  urine  or  other  causes.  The  part  of  the  blad 
der  upon  which  this  appears  chiefly  to  act,  is  the  trigonum  (which  is  well  known 
to  be  more  sensitive  to  the  irritation  of  calculi,  than  the  rest  of  the  internal  sur- 
face); and  Sir  C  Bell  advises  young  persons  who  suffer  during  the  night  from 
this  very  disagreeable  complaint,  to  lie  upon  the  belly  instead  of  the  back,  so  that 
the  contact  of  the  urine  with  the  trigonum  may  be  delayed  as  long  as  possible. — 

1  The  influence  of  "change  of  nir"  is  often  as  marked  in  this  disease,  as  it  is  in  the 
chronic  stage  of  hooping-cough.  That  an  impure  atmosphere  is  of  itself  sufficient  to 
induce  fatal  convulsive  disorders  in  infants,  has  been  proved  on  a  former  occasion 


648  FUNCTIONS    OF    THE    CEREBRO-SPINAL    NERVOUS    SYSTEM. 

Various  remedial  agents  will  probably  be  found  to  operate,  by  occasioning  increased 
excitability  in  some  particular  segments  of  the  Cord ;  so  that  the  usual  stimuli 
applied  to  the  parts  connected  with  these,  will  occasion  increased  muscular  tension. 
This  seems  to  be  the  case,  for  example,  in  regard  to  the  influence  of  aloes  on  the 
rectum  and  uterus,  cantharides  on  the  neck  of  the  bladder  and  adjoining  parts, 
and  secale  cornutum  on  the  uterus.  The  mode  of  influence  of  cantharides  is 
illustrated  by  a  curious  case,  related  by  Dr.  M.  Hull,  of  a  young  lady  who  lost 
the  power  of  retention  of  urine,  in  consequence  of  a  fatty  tumour  in  the  spinal 
canal,  which  gradually  severed  the  Spinal  Cord,  and  induced  paraplegia.  The 
power  of  retaining  the  urine  was  always  restored  for  a  time  by  a  dose  of  tincture 
of  Cantharides,  which  seems  to  have  acted  by  augmenting  the  activity  of  that 
segment  of  the  Cord  with  which  the  sphincter  vesicae  is  connected. 

725.  As  Convulsive  diseases  are  dependent  upon   excessive   activity  of  the 
Spinal  centres,  so  do  various  forms  of  Paralysis  arise  from  disease  of  the  Cord, 
affecting  its  proper  ganglionic  substance,  or  the  connections  of  its  nerve-roots 
with  the  Encephalon.     If  the  latter  only  be  impaired,  we  have  an  interruption 
of  sensibility  and  voluntary  motion,  the  reflex  actions  of  the  Spinal  ganglia  being 
still  manifested  ;  but  if  the  former  be  involved,  these  reflex  actions  are  suspended 
no  less  completely  than  are  the  sensori-volitional.     There  are  many  peculiar  phe- 
nomena of  Paralysis  depending  on  Spinal  lesion,  however,  which  have  not  yet 
been  explained  on  any  physiological  basis.     Among  these  is  the  fact,  to  which 
Dr.  Gull  has  prominently  directed  attention,1  that  in  Paraplegia  dependent  upon 
lesion  of  the  Cord,  there  is  usually  greater  loss  of  motion   than   of  sensation ; 
whilst  in  Paraplegia  dependent  upon  Encephalic  disorder,  or  upon  toxic  agencies 
rather  affecting  the  peripheral  than  the  central  portions  of  the  nervous  system 
(as  seems  to  be  generally  the  case,  for  example,  in  poisoning  by  lead),  affections 
of  the  sensibility,  sometimes  beginning  with  hypersesthesia,  and  then  proceeding 
to  more  or  less  complete  anaesthesia,  usually  constitute  the  prominent  symptoms. 

726.  Our  present  knowledge  of  the  Physiology  and  Pathology  of  the  Cerebel- 
lum seems  to  justify  the  inference,  that  its  special  function  consists  in  the  co- 
ordination of  voluntary  movements;  and  the  effects  of  lesions  whose  influence  is 
limited  to  this  organ,  display  themselves  most  constantly  in  the  impairment  of 
this  power. — But  there  are  pathological  phenomena  which  seem  to  indicate,  that 
a  centre  of  sexual  sensation  has  its  place  in  or  near  the  central  lobe  of  the  Cere- 
bellum, and  that,  according  to  the  degree  of  excitement  or  of  depression  of  its 
functional  activity,  will  be  the  strength  or  weakness  of  the  sexual  desire  prompted 
by  the  sensation. 

[In  the  foregoing  view  of  the  Functions  of  the  Nervous  System,  the  Author  has  endea- 
voured to  exhibit  this  most  difficult  and  in  many  parts  obscure  subject,  under  the  aspect 
in  which  it  now  presents  itself  to  his  own  mind  ;  believing  that  he  could  thus  best  explain 
it  to  his  readers.  As  his  views  have  been  arrived-at  by  his  own  careful  study  of  the  sub- 
ject, he  has  not  thought  it  necessary  to  be  continually  referring  to  other  Physiologists, 
with  whose  doctrines  his  own  may  Jjave  more  or  less  of  coincidence.  He  would  here  state, 
once  for  all,  that  of  the  older  writers  on  this  branch  of  Physiology,  he  regards  Unzer  and 
Prochaska  (whose  treatises  have  been  lately  re-published  by  the  Sydenham  Society)  as 
having  displayed  the  deepest  insight  into  the  truth ;  their  doctrines  requiring  little  more 
than  the  correction  and  extension  which  subsequent  anatomical  discoveries  have  afforded, 
to  form  part  of  the  present  fabric  of  the  science.  And  he  considers  it  as  no  unimportant 
confirmation  of  his  own  views,  that  although  arrived-at  in  complete  ignorance  of  what  Un- 
zer had  long  previously  put-forth,  they  have  proved  to  be  in  harmony,  on  all  essential 
points,  with  those  of  so  philosophic  and  penetrating  a  thinker. — Of  modern  Neurologists, 
the  foremost  rank  is  justly  to  be  assigned  to  Sir  C.  Bell,  for  his  discovery  of  the  anatomi- 
cal distinctness  of  the  sensory  and  motor  nerves,  and  for  the  inferences  to  which  this  dis- 
covery led.  And  the  Author  is  quite  of  opinion  that  the  re-discovery  of  the  Reflex  Func- 
tion of  the  Spinal  Cord  by  Dr.  M.  Hall  (which  he  believes  to  have  been  entirely  original 
on  that  gentleman's  part)  has  constituted  an  era  of  no  less  importance:  although  Dr.  H.'a 
limitation  of  the  doctrine  of  reflex  action  to  the  Spinal  centres,  has  subsequently  tended, 


Gulstonian  Lectures  on  the  Nervous  System,'  in  "Medical  Times,"  1849,  No.  495. 


OF     SENSIBILITY    IN     GENERAL.  649 

in  the  Author's  opinion,  rather  to  retard  than  to  promote  the  progress  of  Neurology.  In 
extending  this  view  to  the  Sensory  Ganglia,  and  in  showing  that  they  minister  to  a  class 
of  reflex  actions  peculiarly  their  own,  the  Author  believes  that  he  may  claim  to  have  made 
the  first  definite  attempt  to  free  it  from  this  limitation;  and  for  its  further  extension  to 
the  Cerebrum,  Science  is  indebted  to  Dr.  Laycock,  to  whose  Essay  on  the  Reflex  Action  of 
the  Brain,  the  Author  has  already  expressed  his  obligations.  To  these  he  would  add  the 
names  of  Sir  H.  Holland  and  Dr.  Todd,  as  those  of  writers  from  whom  he  has  derived 
many  valuable  suggestions,  which  have  not,  he  trusts,  been  without  fruit  in  his  own  mind. 
— It  is  a  circumstance  not  devoid  of  interest,  that,  during  the  present  century,  notwith- 
standing the  large  amount  of  anatomical  and  experimental  inquiry  which  has  been  directed 
to  the  Nervous  System  both  in  France  and  in  Germany,  and  the  vast  addition  to  our  know- 
ledge of  details  which  has  hence  arisen,  the  great  advances  in  the  general  doctrines  of  this 
department  of  the  science  should  have  been  made  by  British  Physiologists.] 


CHAPTER  XIT. 

OF   THE    ORGANS   OF   THE    SENSES,    AND    THEIR   FUNCTIONS. 

1.- — Of  Sensibility  in  General. 

727.  We  have  seen  that  the  conscious  Mind  is  affected  by  impressions  made 
upon  the  corporeal  organism, — or,  in  other  words,  that  Sensation  is  produced, — 
through  the  instrumentality  of  a  certain  part  of  the  Encephalon  termed  the 
Sensor  item,  which  is  the  general  centre  of  the  nerves  both  of  'special'  and  of 
'  common'  sensibility;  the  former  connect  it  with  the  special  Organs  of  Sense, 
the  latter  with  the  body  generally,  to  the  several  parts  of  which  they  are  by  no 
means  uniformly  distributed,  some  tissues  being  altogether  destitute  of  them. 
Those  parts  of  the  body  which  are  endowed  with  sensory  fibres,  and  impressions 
on  which,  therefore,  give  rise  to  sensation,  are  ordinarily  spoken-of  as  sensible; 
and  different  parts  are  said  to  be  sensible  in  different  degrees,  according  to  the 
strength  of  the  sensation  produced  by  a  corresponding  impression  on  each.  In 
accordance  with  the  general  fact  of  the  dependence  of  all  Nervous  action  on  the 
continuance  of  the  Circulation  of  the  blood  (see  PRINC.  OF  GEN.  PHYS.,  Am.  Ed.), 
.t  is  found  that  the  sensory  nerves  are  distributed  pretty  much  in  the  same  propor- 
tion as  the  blood-vessels;  that  is  to  say,  in  the  non-vascular  tissues,— such  as  the 
epidermis,  hair,  nails,  cartilage,  and  bony  substance  of  the  teeth, — no  nerves 
exist,  and  there  is  an  entire  absence  of  sensibility;  and  in  those  whose  vascu- 
larity  is  trifling,  as  is  the  case  with  bones,  tendons,  ligaments,  fibrous  membranes, 
and  other  parts  whose  functions  are  simply  mechanical,  and  even  with  serous  and 
areolur  membranes,  there  are  few  nerves,  and  the  sensibility  is  dull.  Many  of 
these  textures  are  acutely  sensible,  however,  under  certain  circumstances ;  thus, 
although  tendons  and  ligaments  may  be  wounded,  burned,  &c.,  without  giving 
rise  to  much  consciousness  of  the  injury,  they  cannot  be  stretched  without  the 
production  of  considerable  pain ;  and  the  fibrous,  serous,  and  areolar  tissues, 
when  their  vascularity  is  increased  by  inflammation,  also  become  extremely  sus- 
ceptible of  painful  impressions.  All  very  vascular  parts,  however,  do  not  possess 
acute  sensibility;  the  muscles,  for  instance,^are  furnished  with  a  large  supply  of 
blood,  to  enable  them  to  perform  their  peculiar  function  ;  but  they  are  not  sensi- 
ble in  by  any  means  the  same  proportion.  Even  the  substance  of  the  brain,  and 
of  the  nerves  of  special  sensation,  appears  to  be  destitute  of  this  endowment; 
and  the  same  may  be  said  of  the  mucous  membranes  lining  the  interior  of  the 
several  viscera,  which,  in  the  ordinary  condition,  are  much  less  sensible  than  the 
membranes  that  cover  those  viscera,  although  so  plentifully  supplied  with  blood 
for  their  especial  purposes.  The  most  sensible  of  all  parts  of  the  body,  is  the 
Skin,  in  which  the  sensory  nerves  spread  themselves  out  into  a  minute  network  ; 
and  even  of  this  tissue,  the  sensibility  differs  greatly  in  different  parts  (§  733). — 


650         OF   THE    ORGANS    OF   THE    SENSES,    AND    THEIR    FUNCTIONS. 

The  organs  of  Special  Sensation  become,  by  the  peculiar  character  of  the  nerves 
with  which  they  are  supplied,  the  recipients  of  impressions  of  a  particular  kind; 
thus,  the  Eye  is  sensible  to  light,  the  Ear  to  sound,  &c. ;  and  whatever  amount 
of  ordinary  sensibility  they  possess,  is  dependent  upon  other  sensory  nerves. 
The  eye,  for  example,  contrary  to  the  usual  notions,  is  a  very  insensible  part  of 
the  body,  unless  affected  with  inflammation ;  for  though  the  mucous  membrane 
which  covers  its  surface,  and  which  is  prolonged  from  the  skin,  is  acutely  sensible 
to  tactile  impressions,  the  interior  is  by  no  means  so,  as  is  well  known  to  those 
who  have  operated  much  on  this  organ.  And  the  common  sensory  nerves,  which 
supply  certain  parts  of  the  body,  are  adapted  to  receive  and  convey  to  the  mind 
impressions  of  particular  kinds,  with  much  greater  readiness  than  they  commu- 
nicate those  of  a  different  description  ;  thus  the  sensibility  to  tickling  is  much 
/ greater  on  some  parts  of  the  surface  than  on  others;  and  this  kind  of  excite- 
ment, applied  to  the  genitals  or  to  the  nipple,  produces  sensations  of  a  most 
peculiar  order. 

728.  An  active  Capillary  Circulation  being  essential  to  the  sensibility  of  every 
part  supplied  with  nerves,  any  cause  which  retards  this  deadens  the  sensibility, 
as  is  well  seen  with  regard  to  Cold ;  and,  on  the  other  hand,  an  increase  in  its 
energy  produces  a  corresponding  increase  in  the  sensibility,  as  is  peculiarly  evi- 
dent in  the  'active  congestion'  which  usually  precedes  and  accompanies  Inflam- 
mation.    A  diminution  or  increase  of  sensibility  to  external  impressions  may 
arise,  however,  not  only  from  an  abnormal  state  of  the  circulation  in  the  organ 
or  part  itself,  but  from  the  similar  conditions  affecting  that  part  of  the  Senso- 
rium  in  which  the  impressions  are  received.     Thus  in  those  various  conditions 
of  the  Encephalon,  in  which  either  a  stagnation  of  the  circulation,  or  an  abnor- 
mal state  of  the  blood  (such  as  that  produced  by  anaesthetic  agents),  occasions  a 
diminished  functional  activity  in  the  Sensorial  centres,  this  is  marked  by  obtuse- 
ness  to  sensory  impressions;  on  the  other  hand,  in  active  congestion  of  the  brain, 
the  most  ordinary  external  impressions  produce  sensations  of  an  unbearable  vio- 
lence; and  in  that  peculiar  condition  of  the  nervous  system  known  under  the 
name  of  Hysterical  (§  723),  the  patients  often  manifest  the  same  hyperaesthesia 
even  when  the  circulation  is  in  a  feeble,  rather  than  in  an  excited  state.1     It  is 
remarkable  that  the  sensibility  of  the  mucuous  membranes  lining  the  internal 
organs,  is  less  exalted  by  the  state  of  inflammation,  than  is  that  of  most  other 
parts;  and  in  this  arrangement  we  may  trace  a  wise   and  beneficent  provision; 
since,  were  it  otherwise,  the  functions  necessary  to  life  could  not  be  performed 
without  extreme  distress,  whenever  a  very  moderate  amount  of  disorder  might 
exist  in  the  viscera.     If  a  joint  is  inflamed,  we  can  give  it  rest ;  but  to  the  actions 
of  the  alimentary  canal  we  can  give  little  voluntary  respite. 

729.  It  is  through  the  medium  of  Sensation,  that  we  acquire  a  knowledge  of 
the  material  Universe  around  us,  by  the  psychical  operations  which  its  changes 
excite  in   ourselves.     The  various  kinds   or  modes   of  Sensation  suggest  to  us 
various  ideas  regarding  the  properties  of  matter;  and  these  properties  are  known 
to  us,  only  through  the  changes  which  they  produce  in  the  several  organs  (§  591). 
It  is  well  known  that  instances  exist,  in  which,  from  some  imperfection  of  the 
organization,  there  is  an  incapacity  for  distinguishing  colours  or  musical  tones, 
whilst  there  is  no  want  of  sensibility  to  light  or  sound ;  and  that  some  persons 
are  naturally  endowed  with  a  much  greater  range  of  the  sensory  faculties,  than 
others  possess.     Hence  it  does  not  seem,  at  all  improbable,  that  there  are  pro- 
perties of  matter,  of  which  none  of  our  senses  can  take  immediate  cognizance ; 
and  which  other  beings  might  be  formed  to  perceive,  in  the  same  manner  as  we 
are  sensible  to  light,  sound,  &c.     Thus  many  animals  are  affected  by  atmospheric 

1  The  influence  of  toxic  agents  introduced  into  the  blood,  in  producing  Anaesthesia  and 
Hypernesthesia,  constitutes  a  very  wide  field  of  inquiry,  which  is  well  deserving  of  careful 
cultivation.  It  is  remarkable  that  Lead  and  Alcohol  should  be  capable  of  inducing  either 
of  these  states. 


OF    SENSIBILITY    IN    GENERAL.  651 

changes,  in  such  a  manner  that  their  actions  are  regarded  by  Man  as  indications 
of  the  probable  state  of  the  weather;  and  the  same  is  the  case  in  a  less  degree 
with  some  of  our  own  species,  who  are  peculiarly  susceptible  of  the  like  influ- 
ences— j\jow  the  most  universal  of  all  the  qualities  or  properties  of  Matter,  on 
which,  in  fact,  our  notion  of  it  is  chiefly  founded  (§  584),  is  its  occupation  of 
space,  producing  a  more  or  less  complete  resistance  to  displacement;  and  this 
quality  is  that  through  which  alone  any  knowledge  of  the  external  world  can  be 
obtained  by  a  large  proportion  of  the  lower  Animals;  contact  between  their  own 
surface  and  some  material  body,  being  required  to  produce  sensation.  We  shall 
presently  see,  however,  that  the  idea  of  the  shape  of  a  body  which  we  form  from  the 
touch,  results  from  a  very  complex  process,  such  as  animals  of  the  lower  grades 
can  scarcely  be  supposed  to  exercise.  There  can  be  little  doubt  that,  next  to  the 
mere  sense  of  resistance,  sensibility  to  temperature  is  the  most  universally  dif- 
fused through  the  Animal  kingdom ;  and  probably  the  consciousness  of  lumi- 
nosity is  the  next  in  the  extent  of  its  diffusion.1  It  is  probable  that  the  sense 
of  taste  (which  has  a  close  affinity  to  that  of  touch)  exists  very  low  down  in  the 
animal  scale,  being  obviously  of  great  importance  in  the  selection  of  food;  but 
the  Anatomist  has  no  means  of  ascertaining  where  this  refinement  exists,  and 
where  it  does  not ;  since  the  organs  of  taste  and  touch  are  very  similar.  The 
sense  of  hearing  does  not  seem  to  be  distinctly  present  among  the  Invertebrate 
animals,'  except  in  such  as  approach  most  nearly  to  the  Vertebrata ;  it  is  not  im- 
probable, however,  that  sonorous  vibrations  may  produce  an  effect  upon  the 
system  of  those  animals  which  do  not  receive  them  as  sound.  The  sense  of 
smell,  which  is  concerned  with  one  of  the  least  general  properties  of  matter, 
appears  to  be  the  least-widely  diffused  among  the  whole ;  being  only  possessed 
in  any  high  degree  by  Vertebrated  animals,  and  being  but  feebly  present  in  a 
large  proportion  of  these. 

730.  Besides  the  various  kinds  of  sensibility  which  have  been  just  enume- 
rated, there  are  others  which  are  ordinarily  associated  together,  along  with  the 
sense  of  material  resistance  (and  its  several  modifications),  and  the  sense  of 
temperature,  under  the  head  of  Common  Sensation ;  but  several  of  them,  espe- 
cially those  which  originate  in  the  body  itself,  can  scarcely  be  regarded  in  this 
light.  Such  are  the  feelings  of  hunger  and  thirst ;  that  of  nausea ;  that  of  dis- 
tress resulting  from  suspended  aeration  of  the  blood ;  that  of  '  sinking  at  the 
stomach/  as  it  is  vulgarly  but  expressively  described,  which  results  from  strong 
mental  emotion ;  the  sexual  sense,  and  perhaps  some  others.  — Now  in  regard  to 
all  these,  it  is  impossible  in  the  present  state  of  our  knowledge  to  say,  whether 
their  peculiarity  results  from  the  particular  constitution  of  the  nerves  that  receive 
and  convey  them,  or  only  from  a  modification  of  the  impressing  causes,  from  the 
particular  endowments  of  their  ganglionic  centres,  and  from  the  mode  in  which 
they  operate.  Thus  we  have  no  evidence  whether  the  nervous  fibrils,  which 
convey -from  the  lungs  the  sense  of  distress  resulting  from  deficient  aeration,  are 
of  the  same  or  of  a  different  character  from  those  which  convey  from  the  surface 
of  the  air-passages  the  sense  of  the  contact  of  a  foreign  body.  But  as  we  know 
that  all  the  trunks  along  which  these  peculiar  impressions  travel,  do  minister  to 
ordinary  sensation,  whilst  the  nerves  of  truly  <  special '  sensation  are  not  sensible 
to  tactile  impressions,  it  is  evident  that  the  probability  seems  in  favour  of  the 
identity  of  the  fibres  which  minister  to  these  sensations,  with  those  of  the  usual 
sensory  character.  We  shall  see  that  with  regard  to  the  sense  of  temperature,  there 

1  There  is  good  reason  to  believe,  from  observation  of  their  habits,  that  many  animals 
are  susceptible  of  the  influence,  and  are  directed  by  the  guidance,  of  light,  whose  organs 
are  not  adapted  to  receive  true  visual  impressions,  or  to  form  optical  images ;  and  such 
would  seem  to  be  the  function  of  the  red  spots,  frequently  seen  on  prominent  parts  of  the 
lower  Articulata  and  Mollusca,  and  even  of  some  Radiata.  Wherever  these  are  of  suf- 
ficient size  to  allow  their  structure  to  be  examined,  they  are  found  to  be  largely  supplied 
with  nerves,  but  to  be  destitute  of  the  peculiar  organization  which  alone  constitutes  a 
true  eye 


652         OF    THE    ORGANS    OF   THE    SENSES,    AND   THEIR   FUNCTIONS. 

is  strong  evidence  that  its  peculiarity  depends  on  the  speciality  of  the  apparatus 
by  which  impressions  are  received  at  the  peripheral  extremities  of  the  tactile 
nerves,  rather  than  upon  any  peculiarity  in  the  transmitting  fibres  (§  736). 

731.  There  are  certain  external  agencies,  which  can  excite  changes  in  the 
Sensorium  through  several  different  channels ;  the  sensation  being  in  each  case 
characteristic  of  the  particular  nerve  on  which  the  impression  is  made.  Thus 
pressure,  which  produces  through  the  nerves  of  common  sensation  the  feeling  of 
resistance,  is  well  known  to  occasion,  when  exerted  on  the  eye,  the  sensation  of 
light  and  colours;  and,  when  made  with  some  violence  on  the  ear,  to  produce 
'  tinnitus  aurium/  It  is  not  so  easy  to  excite  sensations  of  taste  and  smell,  by 
mechanical  irritation  ;  and  yet,  as  Dr.  Baly '  has  shown,  this  may  readily  be  ac- 
complished in  regard  to  the  former.  [A  singular  instance  of  deprivation  of  the 
senses  of  taste  and  smell,  and  of  the  existence  of  subjective  sensations,  is  related 
by  Mr.  Justice,  in  the  Transactions  of  the  American  Philosophical  Society,  Phila- 
delphia, 1854.  About  nine  months  since,  a  person  of  his  acquaintance  was 
thrown  from  his  carriage  while  riding.  In  his  fall,  his  head  first  came  in  contact 
with  the  ground,  producing  a  concussion  of  the  brain.  The  injury  appeared  to 
have  been  received  behind,  but  above  the  ear.  He  was  laid  on  his  bed  in  a  state 
of  total  insensibility,  and  so  remained  for  nearly  a  month,  about  which  time  he 
revived,  and  to  his  surprise  found  that  he  had  entirely  lost  both  the  senses  of 
taste  and  smell.  In  this  situation  he  still  remains,  and  it  is  now  equally  indif- 
ferent to  him  what  he  partakes  of  as  food,  as  far  as  regards  all  taste ;  —  Cayenne 
pepper  or  saw-dust,  as  he  expressed  it,  being  alike  tasteless.  But,  as  a  compen- 
sation for  this  loss,  he  enjoys  a  constant  sensation  of  a  most  delightful  character, 
which  he  can  only  compare  to  the  most  delicious  cordial  flowing  through  his 
inouth.  This  continues  night  and  day,  and  is  particularly  perceptible  when  his 
lips  are  apart  and  he  inhales  the  air  through  his  mouth.  The  only  intermission 
to  this  pleasurable  sensation  is  while  he  is  partaking  of  his  food. — ED.]  The 
sense  of  nausea  maybe  easily  produced,  as  is  familiarly  known,  by  mechanical  ir- 
ritation of  the  fauces.  Electricity  still  more  completely  possesses  the  power  of 
affecting  all  the  sensory  nerves  with  the  changes  which  are  peculiar  to  them ; 
for,  by  proper  management,  an  individual  may  be  made  conscious  at  the  same 
time  of  flashes  of  light,  of  distinct  sounds,  of  a  phosphoric  odour,  of  a  peculiar 
taste,  and  of  pricking  sensations,  all  excited  by  the  same  cause,  the  effects  of 
which  are  modified  by  the  respective  peculiarities  of  the  instruments  through 
which  it  operates.  — But  although  there  are  some  stimuli  which  can  produce  sen- 
sory impressions  on  all  the  nerves  of  sensation,  it  will  be  found  that  those  to 
which  any  one  organ  is  peculiarly  fitted  to  respond,  produce  little  or  no  effect 
upon  the  rest.  Thus  the  ear  cannot  distinguish  the  slightest  difference  between  a 
luminous  and  a  4ark  object.  A  tuning-fork,  which,  when  laid  upon  the  ear  whilst 
vibrating,  produces  a  distinct  musical  tone,  excites  no  other  sensation  when  placed 
upon  the  eye,  than  a  slight  jarring  feeling.  The  most  delicate  touch  cannot  dis- 
tinguish a  substance  which  is  sweet  to  the  taste,  from  one  which  is  bitter;  nor 
can  the  taste  (if  the  communication  between  the  mouth  and  the  nose  be  cut-off) 
perceive  anything  peculiar  in  the  most  strongly-odoriferous  bodies.  —  It  may 
hence  be  inferred  that  no  nerve  of  special  sensation  can,  by  any  possibility,  take- 
on  the  function  of  another. 

2. — Sense  of  Touch. 

732.  By  the  sense  of  Touch,  as  commonly  understood,  is  meant  that  modifica- 
tion of  the  common  sensibility  of  the  body,  of  which  the  cutaneous  surface  is 
the  especia1  seat.  The  Skin  is  peculiarly  adapted  for  this  purpose,  not 
merely  by  the  large  amount  of  sensory  nervous  fibres  which  are  distributed  in 
its  substance,  but  also  by  its  possession  of  a  papillary  apparatus  in  which  these 
nerves  terminate,  or  rather  commence.  The  papillae  are  little  elevations  of  th<* 
1  Translation  of  Miiller's  "  Elements  of  Physiology,"  p.  1062  note. 


SENSE     OF    TOUCH. 


653 


FIG.  154. 


surface  of  the  cutis,  usually  simply- 
conical  or  clavate  in  form  (Fig.  153), 
but  sometimes  presenting  numerous 
summits.  On  the  palmar  surface  of 
the  hand,  they  are  arranged  in  rows; 
and  they  are  there  so  numerous,  that 
(according  to  E.  H.  Weber)  as  many 
as  81  compound,  or  from  150  to  200 
simple  papillae,  are  contained  within 
the  area  of  a  square  (Paris)  line.  The 
papillae  are  also  very  numerous,  though 
without  any  definite  arrangement,  on 
the  red  surface  of  the  lips,  on  the 
penis  of  the  male,  on  the  labia  minora 

and  clitoris  of  the  female,  and  on  the  Vertical  Section  of  the  Skin  of  the  palmar  sur- 
nipples  of  both  sexes }  but  elsewhere  face  of  the  fore-finger  (treated  with  a  solution  cf 
they  are  scattered  more  widely  apart.  caustic  soda)'  showing  the  branches  of  cutaneous 
Each  sensory  papilla  receives  one  or  "f™"'  "'  b>  inoscula«nS  to  fo™  a  terminal 

plexus,  of  which  the  ultimate  ramifications  pass 

more    nerve-fibres    from    the    plexus  fnto  the  cutaneous  papmjB  c>  c>  c, 
which  is  formed  by  the    inosculation 

of  the  ramifications  of  the  cutaneous  nerves  (Fig.  153);  and  these  nerve-fibres 
seem  to  terminate  (at  least  in  the  papillae  01  the  palm  of  the  hand,  and  of  the 
lips,  and  in  the  simple  papillae 
of  the  tongue,  §  741)  in  a  pecu- 
liar l  axile  body/  which  occupies 
the  principal  part  of  the  interior 
of  the  papilla  (Fig.  154).  With 
regard  to  the  nature  of  this  body, 
there  has  been  considerable  dis- 
cussion between  Prof.  Wagner, 
its  discoverer,  and  Prof.  Kolli- 
ker : '  the  former  regarding  it  as 
an  organ  altogether  sui  generis ; 
whilst  the  latter  maintains  that  it 
is  nothing  else  than  a  mass  of 
homogeneous  connective  tissue, 
with  an  external  layer  of  imper- 
fectly-developed elastic  tissue,  and 
that  it  is  essentially  similar  to  the 
bundles  of  fibrous  tissue  encircled 
by  elastic  fibres,  which  are  to  be 
found  in  the  substance  of  the 
cutis.  This  last  view  is  in  the 

main   sunnorted  bv  Mr    Huxlev        Tactlle  impulse  irom  tne  Skin  or  tbe  palmar  suriace 
,     ,    ?»  of  the  fore-finger,  showing  the  tactile  corpuscles  or  'axile 
who  regards  the     axile   body     as  bodies>5_A,  in  the  natural  state;  B,  treated  with  acetic 
formed  by  the  continuation  and  acid, 
increased     development    of    the 

neurilemma  of  the  nerve-tubes  which  enter  the  papilla,  and  as  bearing  a  clost, 
relation  to  the  '  Pacinian  bodies/2  It  was  maintained  by  Wagner,  that  the 
papillae  which  contain  these  bodies,  and  to  which  nerve-fibres  proceed,  contain 

'See  Prof.  Wagner  in  the  Gottingen  "  Gelerhte  Nachrichten "  for  Feb.,  1852,  and 
"Muller's  Archiv.,"  1852,  Heft  4;  and  Prof.  Kolliker  in  "Zeitschrift  fur  Wissenschaft- 
liche  Zoologie,"  June,  1852,  and  in  his  "  Mikroskopische  Anatomic,"  band.  n.  p.  24.  See 
also  Dalzell,  in  "Edinb.  Monthly  Journ.,"  March,  1853. 

*  See  his  Memoir  '  On  the  Structure  and  Relation  of  the  Corpuscula  Tictus,'  in  the 
"  Quarterly  Journal  of  Microscopical  Science,"  vol.  ii.  p.  1. 


Tactile  Papillae  from  the  Skin  of  the  palmar  surface 


FIG.  155. 


654         OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

no  blood-vossels  save  by  coalescence  with  a  vascular  papilla;  whilst  the  vas- 
cular papillae  which  contain  capillary  loops  (Fig.  155),  constitute  a  distinct  order, 
containing  no  nerve-fibres.  This,  however,  is  denied  by  Prof.  Kolliker;  who 

asserts  that  the  corpusculated  papillae  of  the  palm 
of  the  hand  often  contain  vessels,  whilst  the  vas- 
cular papillae  of  the  lip  contain  nerves.  Mr. 
Huxley  states  (loc.  cit.)  that  in  the  human  finger 
he  has  met  with  corpusculated  papillae  containing 
vascular  loops,  though  rarely.  —  The  question  must 
be  regarded  as  still  open  to  investigation;  the  un- 
doubted association  of  capillary  loops  and  nerve- 
tubes  in  the  fungiform  papillae  of  the  Tongue 
(§  741)  rendering  it  improbable  that  there  should 
be  a  complete  dissociation  of  them  in  the  tactile 
papillae  of  the  Skin ;  whilst,  on  the  other  hand,  the 
presence  of  a  true  (vascular)  papillary  structure  where 
a  thick  epidermis  has  to  be  formed,  as  on  the  sole  of  the  foot '  or  the  matrix  of 
the  nail,  seems  to  indicate  that  the  vascular  papillae  of  the  palm  of  the  hand  may 
probably  be  destined  rather  to  this  office,  than  to  participate  in  sensibility.  As 
the  i  axile  bodies'  are  only  to  be  found  in  the  papillae  of  those  parts  which  are  dis- 
tinguished for  acuteness  of  tactile  sensibility,  we  cannot  regard  them  as  essential 
to  the  exercise  of  the  sense  of  touch ;  their  function  probably  being  to  intensify 
tactile  impressions,  where  delicacy"  of  touch  is  particularly  required. 

733.  The  relative  sensibility  of  different  parts  of  the  Skin  maybe  in  some 
degree  judged-of  by  the  results  of  the  observations  of  Prof.  E.  H.  Weber;  whose 
mode  of  ascertaining  it  was  to  touch  the  surface  with  the  legs  of  a  pair  of  com- 
passes, the  points  of  which  were  guarded  with  pieces  of  cork,  and  then  (the  eyes 
being  closed)  the  legs  were  approximated,  until  they  were  brought  within  the 
smallest  distance  at  which  they  could  be  felt  to  be  distinct  from  one  another, 
which  has  been  termed  by  Dr.  Graves  '  the  limit  of  confusion.' — The  following 
are  some  of  the  measurements  thus  taken  : — 


Capillary  loops  in   Cutaneous  pa- 
at  margin  of  lips. 


Point  of  tongue £  of  a  line. 

Palmar  surface  of  third  phalanx  1  line. 

Red  surface  of  lips 2  lines. 

Palmar  surface  of  second  phalanx  2 
Dorsal  surface  of  third  phaJanx  3 
Palmar  surface  of  metacarpus  3 

Tip  of  the  nose 3 

Dorsum  and  edge  of  tongue 4 

Part  of  lips  covered  by  skin  ....    4 

Palm  of  hand 5 

Skin  of  cheek 5 

Extremity  of  great  toe 5 

Hard  palate 6 

Dorsal  surface  of  first  phalanx..  7 
Dorsum  of  hand 8 


Mucous  membrane  of  gums 9  lines. 

Lower  part  of  forehead 10 

Lower  part  of  occiput 12 

Ba.ck  of  hand 14 

Neck,  under  lower  jaw 15 

Vertex 15 

Skin  over  patella 16 

sacrum 18 

acromion 18 

Dorsum  of  foot 18 

Skin  over  sternum 20 

Skin  beneath  occiput 24 

Skin  over  spine,  in  back 30 

Middle  of  the  arm 30 

thigh 30 


It  is  curious  that  the  distance  between  the  legs  of  the  compasses  seemed  to  be 
greater  (although  really  so  much  less),  when  it  was  felt  by  the  more  sensitive 
parts,  than  when  it  was  estimated  by  parts  of  less  distinct  sensibility.  With  the 
extremities  of  the  fingers  and  the  point  of  the  tongue,  the  distance  could  be  dis- 
tinguished most  easily  in  the  longitudinal  direction;  on  the  dorsum  of  the 
tongue,  the  face,  neck,  and  extremities,  the  distance  could  be  recognized  best 
when  the  points  were  placed  transversely.  As  a  general  fact,  it  seems  that  the 
sensibility  of  the  trunk  is  greater  on  the  median  line,  both  before  and  behind, 

1  The  sole  of  the  Dog's  foot  is  furnished  with  vascular  papillae,  the  arrangement  of 
whose  capillaries  very  strongly  resembles  that  of  the  fungiform  papillae  of  the  tongue  ;  and 
fhese  seem  to  be  specially  subservient  to  the  formation  of  its  thick  cuticular  covering. 


SENSE    OF    TOUCH.  655 

and  less  at  the  sides.  Differences  in  the  temperature  and  weight  of  bodies,  were, 
according  to  Prof.  Weber's  observations,  most  accurately  recognized  at  the  parts 
which  were  determined  to  be  most  sensible  by  the  foregoing  method  of  inquiry.1 
— It  has  been  since  found,  however,  by  Prof.  Valentin,  who  has  followed-up  and 
extended  Prof.  Weber's  observations,  that  a  considerable  amount  of  individual 
variation  exists  in  regard  to  the  t  limit  of  confusion ;'  some  persons  being  able  to 
distinguish  the  points  at  one-half  or  even  one-third  of  the  distance  required  by 
others. 

734.  As  already  stated  (§  729),  the  only  idea  communicated  to  our  minds  by 
the  sense  of  Touch,  when  exercised  in  its  simplest  form,  is  that  of  Resistance; 
and  it  is  by  the  various  degrees  of  resistance  which  the  sensory  surface  encounters, 
of  which  we  partly  judge  by  the  muscular  sense  (§  541),  that  we  estimate  the 
hardness  or  softness  of  the  body  against  which  we  press.     It  is  only  when  either 
the  sensory  surface  or  the  substance  touched  is  made  to  change  its  place  in  regard 
to  the  other,  that  we  obtain  the  additional  notion  of  extension  or  space;  this  also 
being  derived  from  the  combination  of  the  muscular  with  the  tactile  sense.     By 
the  impressions  made  upon  the  papillae,  during  the  movement  of  the  tactile  organ 
over  the  body  which  is  being  examined,  the    roughness,  smoothness,  or  other 
peculiar  characters  of  the  surface  of  the  latter  are  estimated.     Our  knowledge  of 
form,  however,  is  a  very  complex  process,  requiring  not  merely  the  exercise  of 
the  sense  of  touch,  but  also  great  attention  to  the  muscular  sensations. — It  is 
chiefly,  as  formerly  remarked,  in  the  variety  of  movements  of  which  the  hand 
of  Man  is  capable,  that  it  is  superior  to  that  of  any  other  animal ;  and  it  cannot 
be  doubted  that  the  sense  of  Touch  thus  employed,  affords  us  a  very  important 
means  of  acquiring  information  in  regard  to  the  external  world,  and  especially  of 
correcting;  many  vague  and  fallacious  notions  which  we  should  derive  from  the 
sense  of  Sight,  if  used  alone.     On  the  other  hand,  it  must  be  confessed  that  our 
knowledge  would  have  a  very  limited  range,  if  this  sense  were  the  only  medium 
through  which  we  could  acquire  ideas.     It  is  probably  on  the  sensations  communi- 
cated through  the  Touch,  that  the  idea  of  the  material  world,  as  something  external 
to  ourselves  chiefly  rests ;  but  this  idea  is  by  no  means  a  logical  deduction  from 
our  experience  of  these  sensations,  being  rather  an  instinctive  or  intuitive  percep- 
tion directly  excited  by  them  (§  604). 

735.  That  the  conditions  under  which  certain  of  the  modifications  of  common 
sensation  operate,  are  in  some  respects  different  from  those  of  ordinary  Touch,  is 
very  easily  shown.    Thus,  the  feeling  of  tickling  is  excited  most  readily  in  parts 
which  have  but  a  low  tactile  sensibility,  namely,  the  armpits,  flanks,  and  soles 
of  the  feet ;  whilst  in  the  points  of  the  fingers,  whose  tactile  sensibility  is  most 
acute,  it  cannot  be  excited.     Moreover,  the  nipple  is  very  moderately  endowed 
with  ordinary  sensibility;  yet  by  a  particular  kind  of  irritation,  a  very  strong 
feeling  may  be  excited  through  it. — Again,  in  regard  to  Temperature,  it  is  re- 
marked by  Weber,  that  the  left  hand  is  more  sensitive  than  the  right;  although 
the  sense  of  touch  is  undoubtedly  the  most  acute  in  the  latter.     He  states  that 
if  the  two  hands,  previously  of  the  same  temperature,  be  plunged  into  separate 
basins  of  warm  water,  that  in  which  the  left  hand  is  immersed  will  be  felt  as  the 
warmer,  even  though  its  temperature  is  somewhat  lower  than  that  of  the  other. 
In  regard  to  the  sensations  of  heat  and  cold,  he  points-out  another  curious  fact, 
that  a  weaker  impression  made  on  a  large  surface,  seems  more  powerful  than  a 
stronger  impression  made  on  a  small  surface ;  thus,  if  the  forefinger  of  one  hand 
be  immersed  in  water  at  104°,  and  the  whole  of  the  other  hand  be  plunged  in 

1  See  his  Memoir  "De  Pulsu,  Respiratione,  Auditu,  et  Tactu,"  Lipsise,  1834.  See  also 
"Recherches  sur  la  Nature,  la  Distribution,  et  1'Organ  du  Sens  Tactile,"  by  M.  H.  Bel- 
field-Lefevre,  Paris,  1837  ;  and  Prof.  Valentin's  "  Lehrbuch  der  Physiologic  des  Meus- 
chen,"  band.  ii.  \  566. — In  the  Author's  article  '  Touch  '  in  the  "  Cyclopaedia  of  Anatomy 
and  Physiology,"  vol.  iv.  p.  1169,  will  be  found  a  Table,  including  the  whole  series  of  ob- 
servations made  by  Profs.  Weber  and  Valentin,  the  maxima  and  minima  of  the  latter  being 
stated  as  well  as  the  means. 


656         OF   THE   ORGANS    OF   THE   SENSES,    AND   THEIR   FUNCTIONS. 

water  at  102°,  the  cooler  water  will  be  thought  the  warmer;  whence  the  well- 
known  fact,  that  water  in  which  a  finger  can  be  held,  will  scald  the  whole  hand. 
Hence  it  also  follows,  that  minute  differences  in  temperature,  which  are  imper- 
ceptible to  a  single  finger,  are  appreciated  by  plunging  the  whole  hand  into  the 
water;  in  this  manner  a  difference  of  one-third  of  a  degree  may  readily  be  de- 
tected, when  the  same  hand  is  placed  successively  in  two  vessels.  The  judgment 
is  more  accurate,  when  the  temperature  is  not  much  above  or  much  below  the 
heat  of  the  body;  just  as  sounds  are  best  discriminated,  when  neither  very  acute 
por  very  grave. 

736.   Some  further  experiments    have    more    recently  been    made   by  Prof. 
Weber,1  to  determine  whether  the  sense  of  Temperature  is  received  through  any 
other  channel  than  the  sensory  apparatus  contained  in  the  integuments.  —  The 
first  means  of  which   he  availed  himself  for  deciding  this  question,  was  that 
afforded  by  the  results  of  accident  or  surgical  operations,  in  which  a  portion  of 
skin  had  been  left  deficient.     Thus,  in  three  cases  in  which  a  large  portion  of 
the  skin  had  been  destroyed  by  a  burn,  and  in  which  healing  had  not  advanced 
so  far  as  to  renew  the  organ  of  touch,  it  was  found  that  no  correct  discrimina- 
tion could  be  made  between  two  spatulas,  one  of  them  at  a  temperature  of  from 
48°  to  54°,  the  other  of  from  113°  to  122°,  which  were  brought  into  contact 
with  the  denuded  surface ;  so  that  one  of  these  patients  thrice  affirmed  that  he 
was  being  touched  with  the  cold  body,  when  it  was  warm,  and  the  reverse.     But 
when  the  spatula  was  in  one  instance  made  somewhat  warmer,  and  was  brought 
into  contact  with  the  unskinned  surface,  the  patient  felt  not  Jieat  but  pain. — 
Another  means  of  gaining  information  on  this  point,  is  afforded  by  the  ingestion 
or  injection  of  a  large  quantity  of  warm  or  cold  fluid  into  the  stomach  or  intes- 
tinal canal.     Thus  Professor  Weber  states,  that  after  drinking  a  tumbler  of  water 
at  32°,  he  felt  the  cold  water  in  the  mouth,  in  the  palate,  and  in  the  pharynx, 
as  far  as  the  limits  of  the  sense  of  touch  ;  but  the  gradual  passage  of  the  cold 
•water  into  the  stomach  could  not  be  perceived.     There  was,  it  is  true,  a  slight 
sensation  of  cold  in  the  gastric  region ;  but  as  it  only  occupied  the  situation  of 
the  anterior  wall  of  the  stomach,  it  was  attributable  to  the  abstraction  of  heat 
horn  the  abdominal  integuments  in  contact  with  this.     In  an  opposite  experi- 
ment, the  author  drank   quickly  three  glasses  of  milk,  the  temperature  of  the 
first  of  which  was  158°,  that  of  the  second  145°,  whilst  that  of  the  third  was  in- 
termediate between  the  two.     The  sensation  of  heat  could  not  be  traced  lower- 
down  than  that  of  the  cold  in  the  previous  experiment.     At  the  moment  when 
the  fluid  entered  the  stomach,  there  was  a  feeling  which  remained  for  some  time, 
but  which  could  not  be  distinguished  as  heat,  being  mistakeable  for  cold.     In 
order  to  ascertain  the  sensation  produced  in  the  large  intestine  by  cold  water,  an 
injection  of  14  ounces  of  water  of  the  temperature  of  65°  was   thrown  up  the 
rectum ;  but  scarcely  any  sensation  of  cold  could  be  perceived  from  it.     In  an- 
other instance,  21  ounces  of  water  at  the  same  temperature  were  thus  injected, 
without  any  resulting  sensation  of  cold.     In  both  these  cases,  on  the  return  of 
tfie  enema  a  few  minutes  afterwards,  a  distinct  feeling  of  cold  was  experienced 
nt  the  anus.     When  water  of  so  low  a  temperature  as  45£°  was  injected,  the  first 
feeling  excited  was  a  sensation  of  cold  in  the  immediate  neighbourhood  of  the 
*,nus,  and  then  a  feeble  movement  in  the  bowels ;  but  a  little  time  afterwards, 
here  was  a  faint  sensation  of  cold,  especially  in  the  anterior  wall  of  the  abdomen. 
This  sensation,  however,  remained  after  the  return  of  the  water;  and  may  hence 
•?e  attributed  to  the  abstraction  of  warmth  from  the  abdominal  integuments, 
which  was   proved  to  have   taken   place,  the   temperature  of  the  surface  being 
lowered  3°.     So,  again,  if  the  cavity  of  the  nose  be  filled  with  cold  water,  the 
coldness  is  only  perceived  in  the  parts  of  the  cavity  which  are  most  endowed  with 
the  proper  tactile  sense,  namely,  the  neighbourhood  of  the   nostrils  and  of  the 
pharynx;  and  it  is  not  at  all  discernible  in  the  higher  part  of  the  cavity,  which 
1  "Miiller's  Archiv.,"  1849,  heft  iv.:.  s.  73—283. 


SENSE    OP    TOUCH.  C57 

is  especially  subservient  to  the  olfactory  sense.  But  when  the  water  injected  is 
very  cold  (e.  y.  41°),  a  peculiar  pain  is  felt  in  the  upper  part  of  the  nasal  fossae, 
extending  to  the  regions  of  the  forehead  and  the  lachrymal  canals;  this  pain, 
however,  is  altogether  different  from  the  sense  of  coldness. 

737.  From  the  foregoing  experiments  it  appears  fair  to  conclude,  that  the 
sensory  nerves  have  no  power  of  receiving  impressions  indicative  of  difference  of  \ 
Temperature,  unless  those  impressions  are  communicated  through  a  special 
organ  ;  but  they  afford  no  adequate  ground  for  the  supposition,  that  a  set  of  nerve- 
fibres  is  provided  for  their  transmission  distinct  from  those  which  minister  to 
common  sensation.  This  condition  is  confirmed  by  the  fact,  that  we  cannot 
excite  impressions  of  heat  or  cold  by  direct  application  to  the  trunks  of  nerves 
which  we  know  must  conduct  such  impressions :  for  the  parts  of  the  skin,  imme- 
diately beneath  which  lie  large  nerve-trunks,  are  not  more  sensitive  to  moderate 
heat  or  cold  than  are  any  others;  whilst  a  greater  degree  of  either  is  felt  as  pain, 
not  as  a  change  of  temperature.  Thus,  a  mixture  of  ice  and  water,  applied  over 
the  ulnar  nerve,  affects  it  in  fifteen  seconds,  and  produces  severe  pain,  having  no 
resemblance  to  cold,  and  such  as  cannot  be  excited  by  the  same  degree  of  cold 
applied  to  any  other  region.  So  the  nerve  of  the  tooth-pulp  is  equally  and  simi- 
larly affected  by  water  of  43°  and  of  112°  j  either  application  causing  a  pain 
exactly  similar  to  that  excited  by  the  other,  or  to  that  produced  by  pressure. 
The  same  is  true  of  the  impressions  received  through  the  skin  itself,  when  they 
pass  beyond  certain  limits  of  intensity;  thus,  the  sensation  produced  by  touching 
frozen  mercury  is  said  to  be  not  distinguishable  from  that  which  results  from 
touching  a  red-hot  iron. 

73&.  The  improvement  in  the  sense  of  Touch,  in  those  persons  whose  depend- 
ence upon  it  is  increased  by  the  loss  of  other  senses,  is  well  known ;  this  ia 
doubtless  to  be  in  part  attributed  (as  already  remarked)  to  the  increased  attention 
which  is  given  to  the  sensations,  and  in  part,  it  may  be  surmised,  to  an  increased 
development  of  the  tactile  organs  themselves,  resulting  from  the  frequent  use  of 
them.  The  process  of  the  acquirement  of  the  power  of  recognized  elevated  cha- 
racters by  the  touch,  is  a  remarkable  example  of  this  improveability.  When  a 
blind  person  first  commences  learning  to  read  in  this  manner,  it  is  necessary  to 
use  a  large  type ;  and  every  individual  letter  must  be  felt  for  some  time,  before 
a  distinct  idea  of  its  form  is  acquired.  After  a  short  period  of  diligent  applica- 
tion, the  individual  becomes  able  to  recognize  the  combination  of  letters  in 
words,  without  forming  a  separate  conception  of  each  letter ;  and  can  read  line 
after  line,  by  passing  the  finger  over  each,. with  considerable  rapidity.  When 
this  power  is  once  thoroughly  acquired,  the  size  of  the  type  may  be  gradually 
diminished ;  and  thus  blind  persons  may  bring  themselves,  by  sufficient  practice, 
to  read  a  type  not  much  larger  than  that  of  an  ordinary  large-print  Bible.  The 
case  of  Saunderson,  who,  although  he  lost  his  sight  at  two  years  old,  became 
Professor  of  Mathematics  at  Cambridge,  is  well  known  j  amongst  his  most  re- 
markable faculties,  was  that  of  distinguishing  genuine  medals  from  imitations, 
which  he  could  do  more  accurately  than  many  connoisseurs  in  full  possession  of 
their  senses.  Several  instances  are  recorded,  of  men  who  became  eminent  as 
Sculptors  after  the  loss  of  their  sight,  and  who  were  particularly  successful  in 
modelling  portrait-busts :  here,  it  is  obvious,  not  merely  the  tactile  but  the  mus- 
cular sensibility  must  be  greatly  augmented  in  acuteness  by  the  habit  of  attend- 
ing to  it.  The  power  of  immediate  recognition  of  individuals  by  the  slightest 
contact  of  the  hands,  even  after  long  periods  of  time,  which  most  blind  and  deaf 
persons  have  displayed,  is  one  of  the  most  curious  examples  of  the  mode  in 
which  tactual  perceptions  will  impress  themselves  on  the  memory,  when  they  are 
habitually  attended-to.  As  an  example  of  the  correct  notions  which  may  be  con- 
veyed to  the  mind,  of  the  forms  and  surfaces  of  a  great  variety  of  objects,  and 
of  the  sufficiency  of  these  notions  for  accurate  comparison,  the  Author  may  men- 
tion the  case  of  a  blind  friend  of  his  own,  who  has  acquired  a  very  complete 
42 


658      OF    THE    OKGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

knowledge  of  Conchology,  both  recent  and  fossil ;  and  who  is  not  only  able  to 
recognize  every  one  of  the  numerous  specimens  in  his  own  cabinet,  but  to  men- 
tion the  nearest  alliances  of  a  shell  previously  unknown  to  him,  when  he  has 
thoroughly  examined  it  by  his  touch.  Many  similar  instances  might  be  cited, 
one  of  the  most  remarkable  being  that  of  John  Gough,  who,  though  blind,  was 
a  noted  botanical  collector,  and  earned  his  livelihood  as  a  land-surveyor.  Several 
cases  are  on  record,1  of  the  acquirement,  by  the  blind,  of  the  power  of  distin- 
guishing the  colours  of  surfaces  which  were  similar  in  other  respects;  and,  how- 
ever wonderful  this  may  seem,  it  is  by  no  means  incredible.  For  it  is  to  be  re- 
membered, that  the  difference  of  colour  depends  upon  the  position  and  arrange- 
ment of  the  particles  composing  the  surface,  which  render  it  capable  of  reflecting 
one  ray  whilst  it  absorbs  all  the  rest;  and  it  is  quite  consistent  with  what  we 
know  from  other  sources,  to  believe  that  the  sense  of  Touch  may  become  so 
refined,  as  to  communicate  a  perception  of  such  differences.2 

3.   Sense  of  Taste. 

739.  The  sense  of  Taste  is  that  by  which  we  distinguish  the  sapid  properties 
of  bodies.  The  term,  as  commonly  understood,  includes  much  more  than  this ; 
being  usually  employed  to  designate  the  whole  of  that  knowledge  of  the  qualities 
of  a  body  (except  such  as  is  purely  tactile),  which  we  derive  through  the  sensory 
apparatus  situated  within  the  mouth.  But  it  will  be  hereafter  shown  that  a  con- 
siderable part  of  this  is  dependent  upon  the  assistance  of  the  olf active  sense 
(§  743) ;  which  is  affected,  through  the  posterior  nares,  by  the  odorous  emana- 
tions of  all  such  bodies  as  are  capable  of  giving  them  off:  and  the  indications  o? 
which  are  so  combined  with  those  of  the  true  gustative  sense,  as  to  make  an  appa 
rently-single  impression  upon  the  Sensorium.  Moreover,  there  are  certain  senso- 
rial  impressions  received  through  the  organ  of  taste,  which  are  so  nearly  allied  in 
their  character  to  those  of  touch,  as  to  render  it  difficult  to  specify  any  fundamen- 
tal difference  between  them :  such  are  the  pungent  sensations  produced  by  mus- 
tard, pepper,  the  essential  oils,  &c. ;  all  of  which  substances,  when  app-lie'd  for  a 
sufficient  length  of  time  to  any  part  of  the  cutaneous  surface,  produce  a  sensation 
which  can  scarcely  be  distinguished  from  that  excited  through  the  organ  of  taste, 
m  any  other  way  than  by  its  inferior  intensity,  and  by  the  absence  of  the  concur- 
rent odorous  emanations.  The  taste  of  such  substances  might  therefore,  perhaps, 
be  considered  as  the  composite  result  of  the  impressions  made  upon  the  sensorium 
through  a  refined  and  acute  touch,  and  by  the  effect  of  their  odorous  emanations 
upon  the  organ  of  smell.  After  making  full  allowance,  however,  for  all  such  as 
can  be  thus  accounted-for,  there  remains  a  large  class  of  pure  sopors,  of  which 
we  take  cognizance  without  the  assistance  of  smell,  and  which  are  altogether  dis- 
similar to  any  tactile  impressions :  such  are  the  bitter  of  quinine,  the  sour  of  tar- 
taric  acid,  the  sweet  of  sugar,  the  saline  of  common  salt,  &c.  The  smell  can  give 
us  no  assistance  in  distinguishing  small  particles  of  these  bodies,  since  they  are 
either  entirely  inodorous,  or  so  nearly  so  as  only  to  be  recognizable  through  its 
moans  when  in  large  masses;  and  the  most  refined  touch  cannot  afford  any  indi- 
cation of  that  kind  of  difference  among  them,  of  which  we  are  at  once  rendered 
cognizant  by  taste. — Of  all  the  <  special '  senses,  however,  that  of  Taste  is  most 
nearly  allied  to  that  of  touch,  as  appears  from  several  considerations.  In  the 
first  place,  the  actual  contact  of  the  object  of  sense  with  the  organ  through  which 
the  impression  is  received,  is  necessary  in  the  present  case,  as  in  the  preceding. 

1  Among  the  best-authenticated  of  these,  is  that  of  a  lady  who  became  blind,  and 
afterwards  deaf,  in  consequence  of  an  attack  of  confluent  small-pox ;  cited  in  Dr.  Kitto'a 
"Lost  Senses,"  vol.  ii.  p.  79,  from  the  "Annual  Register"  for  1758. — Dr.  Kitto's  trea- 
tise may  be  referred-to,  as  containing  a  large  collection  of  interesting  cases  of  a  similar 
description. 

3  For  some  additional  details  in  regard  to  the  sense  of  Touch,  see  the  Author's  article 
•Touch'  in  the  "Cyclopaedia  of  Anatomy  and  Physiology,  vol.  iv. 


SENSE    OF    TASTE.  659 

Again,  it  appears  from  the  considerations  formerly  adduced  (§  495),  that  there  is 
no  special  nerve  of  Taste;  for  the  gustative  impressions  upon  the  front  of  the 
tongue  are  conveyed  by  the  Lingual  branch  of  the  Fifth  pair,  whilst  those  made 
upon  the  back  of  the  organ  are  conveyed  by  the  Glosso-pharyngeal,  both  of  which 
nerves  also  minister  to  common  sensibility;  and  pressure  on  the  trunk  of  either 
of  these  nerves  gives-rise  to  pain,  which  is  not  the  case  with  either  the  olfactory, 
the  optic,  or  the  auditory  nerves.  Moreover,  the  papillary  apparatus,  through 
•which  the  gustative  impressions  are  made  upon  the  extremities  of  these  nerves,  is 
essentially  the  same  in  structure  with  that  of  the  skin. 

740.  For  the  Gustative  nerve-fibres  to  be  impressed  by  the  distinctive  proper- 
ties of  sapid  substances,  it  appears  requisite  that  these  substances  should  be 
brought  into  immediate  relation  with  them,  and  that  they  should  penetrate,  in 
the  state  of  solution,  through  the  investments  of  the  papillae,  into  their  substance. 
This  would  seem  to  be  proved  by  the  two  following  facts :  first,  that  every  sub- 
stance which  possesses  a  distinct  taste  is  more  or  less  soluble  in  the  fluids  of  the 
mouth,  whilst  substances  which  are  perfectly  insoluble  do  not  make  their  presence 
known  in  any  other  way  than  through  the  sense  of  touch;  and,  second,  that  if 
the  most  sapid  substance  be  applied  in  a  dry  state  to  the  papillary  surface,  and 
this  be  also  dry,  no  sensation  of  taste  is  excited.  Hence  it  may  be  inferred  that, 
in  the  reception  of  gustative  impressions,  a  change  is  produced  in  the  molecular 
condition  of  the  nerve-fibres,  or,  to  use  the  language  of  Messrs.  Todd  and  Bow- 
man, their  polarity  is  excited,  by  the  direct  agency  of  the  sapid  matter  itself. 
This  change  may  be  induced,  however,  both  by  electrical  and  by  mechanical  sti- 
mulation. If  we  make  the  tongue  form  part  of  a  galvanic  circuit,  a  peculiar  sen- 
sation is  excited,  which  is  certainly  allied  rather  to  the  gustative  than  to  the  tac- 
tile, and  which  does  not  seem  to  be  due  (as  was  at  one  time  supposed)  to  the 
decomposition  of  the  salts  of  the  saliva.  And,  as  Dr.  Baly  has  pointed-oUt,1  "if 
the  end  of  the  finger  be  made  to  strike  quickly,  but  lightly,  the  surface  of  the 
tongue  at  its  tip,  or  its  edge  near  the  tip,  so  as  to  aifect  not  the  substance  of  the 
organ,  but  merely  the  papillae,  a  taste  sometimes  acid,  sometimes  saline,  like  the 
taste  produced  by  electricity,  will  be  distinctly  perceived.  The  sensation  of  taste 
thus  induced,  will  sometimes  continue  several  seconds  after  the  application  of  the 
mechanical  stimulus/'  On  the  other  hand,  as  Wagner  has  truly  remarked,  if  the 
surface  of  the  tongue  near  the  root  be  touched  with  a  clean  dry  glass  rod,  or  a 
drop  of  distilled  water  be  placed  upon  it,  a  slightly  bitterish  sensation  is  pro- 
duced; and  this,  if  the  pressure  be  continued,  passes  into  that  of  nausea,  and  if 
the  pressure  be  increased,  even  excites  vomiting.  The  feeling  of  nausea  may  be 
excited  by  mechanical  irritation  of  any  part  of  the  surface  of  the  fauces  or  soft 
palate;  and  this  feeling  is  certainly  much  more  allied  to  that  of  taste,  than  to  that 
of  touch.  Further,  it  has  been  observed  by  Henle,  that  if  a  small  current  of  air 
be  directed  upon  the  tongue,  it  gives  rise  to  a  cool  saline  taste  like  that  of  salt- 
petre. Thus  we  find  that  the  peculiar  efiects  of  sapid  substances  upon  the  nerves 
of  taste  may  be  imitated  to  a  certain  extent  by  other  agencies  :  and  it  also  appears 
that  the  sensations  excited  by  these  vary  according  to  the  part  of  the  gustative 
surface  on  which  they  operate;  mechanical  or  electrical  stimulation  of  the  front 
of  the  tongue  giving  rise  to  a  kind  of  saline  taste,  whilst  mechanical  stimulation 
applied  to  the  back  of  the  tongue  and  fauces  excites  the  feelings  of  bitterness  and 
nausea. — One  of  the  conditions  requisite  for  the  due  exercise  of  the  gustative 
sense,  is  a  temperature  not  departing  far  on  either  side  from  that  which  is  natu- 
ral to  the  body.  It  appears  from  the  experiments  of  Prof.  E.  H.  Weber,2  that 
if  the  tongue  be  kept  immersed  for  nearly  a  minute  in  water  of  about  125°,  the 
taste  of  sugar  brought  in  contact  with  it,  either  in  powder  or  solution,  is  no  longer 
perceived ;  the  sense  of  touch,  usually  so  delicate  at  the  tip  of  the  tongue,  being 
also  rendered  imperfect.  A  similar  imperfection  of  taste  and  touch  was  produced 

1  Translation  of  "Miiller's  Physiology,"  p.  1062,  note. 

3  "Miiller's  Archiv.,"  1847,  s.  342. 


060         OF    THE    ORGANS    OF  THE    SENSES,    AND   THEIR   FUNCTIONS. 

by  immersing  the  tongue  for  the  same  length  of  time  in  a  mixture  of  water  and 
broken  ice. 

741.  The  surface  of  the  Tongue  is  undoubtedly  the  special  seat  of  gustative 
sensibility  in  Man ;  though  the  sense  of  Taste  is  not  by  any  means  restricted 
to  that  organ,  being  diffused  in  a  less  degree  over  the  soft  palate,  the  arches  of 
the  palate,  and  the  fauces.  It  is  on  the  tongue  alone,  however,  that  the  papil- 
lary apparatus  is  fully  developed ;  and  its  structure  has  been  so  carefully  exam- 
ined and  described  by  Messrs.  Todd  and  Bowman,1  that  little  remains  to  be  added 
to  their  account  of  it.  The  lingual  papillae  may  be  divided,  in  the  first  place,  into 
the  Simple  and  the  Compound /  the  former  of  which  had  previously  escaped  ob- 
servation, through  not  forming  any  apparent  projection.  The  Simple  papillae 
(Fig.  157)  are  scattered  in  the  intervals  of  the  compound,  over  the  general  surface 


[Fio.  156. 


[Fio.  157. 


Simple  papillae  near  the  base  of  the  tongue:  A,  a,  con- 
cealed under  the  epithelium  ;  6,  uncovered  by  it. — Magni- 
fied 10  diameters.  B.  a.  Arterial  twig,  supplying  their 
capillary  loops,  v.  Vein.  The  vessels  are  all  contained 
Tongue  seen  on  its  upper  surface :  a.  One  within  the  line  b,  b,  of  basement-membrane,  c,  c.  Deeper 
of  the  circarnvallate  papillae,  b.  One  of  the  epithelial  particles  resting  on  the  basement-membrane, 
fungiform  papillae.  Numbers  of  the  conical  d.  Scaly  epithelium  on  the  surface.  The  granular  interior 
papillae  are  seen  about  d,  and  elsewhere,  of  the  papillae  is  represented  at  e.  c.  Papillae  in  which 
e.  Glottis,  epiglottis,  and  glosso-epiglotti-  the  basement-membrane  is  not  visible;  and  the  deep  layer 
dean  folds  of  mucous  membrane.  From  of  epithelium  seems  to  rest  on  the  capillary  loop. — Magni 
Sceinmering  ]  fied  200  diameters.] 

of  the  tongue ;  and  they  occupy  much  of  the  surface  behind  the  circumvallate 
variety,  where  no  compound  papillae  exist.  They  are  completely  buried  and  concealed 
beneath  the  continuous  sheet  of  epithelium,  and  can  only  be  detected  when  this 
membrane  has  been  removed  by  maceration  ;  they  are  then  found  to  have  the  gene- 
ral characters  of  the  cutaneous  papillae.  The  Compound  papillae  (Fig.  158)  are 
visible  to  the  naked  eye;  and  have  been  classified,  according  to  their  shape,  into  the 
circumvallate,  tbefunyiform,  and  the  filiform.  The  circumvaUote  or  calyciform 
•'Physiological  Anatomy  and  Physiology  of  Man,"  p.  380,  Am.  Ed. 


SENSE    OF    TASTE. 
[Fro.  158. 


661 


A.  Compound  papillae  on  the  side  of  the  foramen  caecum,  injected :  a,  a.  Arterial  twigs. 
9,  v.  Veins.     The  capillary  loops  indicate  the  simple  papilla? ;  in  one  of  which,  6,  the  injected 
matter  has  been  extravasated  within  the  basement-membrane  of  the  papillae,  the  outline  of 
which  is  thus  distinguished,     c.  Capillary  plexus,  where  no  papillae  exist,     e,  e.  External  sur- 
face of  the  epithelium  of  the  papillae. — Magnified  15  diameters. 

B.  One  of  the  simple  papillae  of  A :  a,  v,  v.  Arterial  and  venous  sides  of  the  capillary  loops. 
b,  b.  Basement-membrane,     d.  Deeper  epithelial  particles  resting  on  the  basement-membrane. 
«.  Scaly  epithelium  on  the  surface.     Magnified  300  diameters.] 

Vertical  section  of  one  of  the  circumvallate  papillae  : 
o.  Central  part,  b,  b.  Border,  c,  c.  Fissure  between 
centre  and  border.  The  secondary  papillae  are  seen 
covered  by  the  epithelium.  Similar  papillee  are  seen, 
d,  d,  on  the  membrane  beyond.  —  Magnified  8 
diameters.] 

papillae  (Fig.  159)  are  eight  or  ten  in  number,  and  are  situated  in  a  V-shaped  line 
at  the  base  of  the  tongue  (Fig.  156).  Each  consists  of  a  central  flattened  circular 
projection  of  the  mucous  membrane,  surrounded  by  a  tumid  ring  of  about  the  same 
elevation,  from  which  it  is  separated  by  a  narrow  circular  fissure  (Fig.  159).  The 
surface  of  both  centre  and  border  is  smooth,  and  is  invested  by  scaly  epithelium, 
which  conceals  a  multitude  of  simple  papillae.  The  fungiform  papillae  (Fig.  160) 

[Fie.  160. 


A.  Fungiform  papilla,  showing  the  secondary  papillae  on  its  surface,  and  at  a  its  epithelium 
covering  them  over. — Magnified  35  diameters. 

B.  Another,  with  the  capillary  loops  of  its  simple  papillae  injected,     a.  Artery,     v.  Vein. 
The  groove  around  the  base  of  some  of  the  fungiform  papillae  is  here  represented  as  well  M 
the  capillary  loops,  c,  c,  of  some  neighbouring  simple  papillae. — Magnified  18  diameters.] 


0»"'«2         OF    THE    ORGANS    OF    THE    SENSE?,    AND    THEIR    FUNCTIONS. 

are  scattered  singly  over  the  tongue,  chiefly  upon  its  sides  and  tip.     They  pro- 
ject considerably  from  the  surface,  and  are  usually  narrower  at  their  base  than 
at  their  summit.     They  contain  a  complex  capillary 
FIG.  161.  plexus  (Fig.  161),  the  terminal  loops  of  which  enter 

the  numerous  simple  papillse  that  clothe  the  surface 
of  the  fungiform  body.  Amidst  those  lie  nerve- 
tubes,  which  probably  have  a  looped  arrangement;1 
and  the  epithelium  which  covers  them  is  so  thin,  as 
to  allow  the  red  colour  of  the  blood  to  be  seen 
through  it.  In  this  manner  they  are  readily  distin- 
guished from  the  filiform  papillse,  among  which  they 
lie.  The  filiform  papillse,  like  the  preceding,  contain 
Capillary  plexus  of/wn^/orw  a  plexus  of  capillaries,  and  a  bundle  of  nerve-fibres, 
**#*'*  both  terminating  in  loops,  which  euter  the  simple 

[FiG.  162. 


(I 


a  l    A 

A.  Vertical  section  near  the  middle  of  the  dorsal  surface  of  the  tongue;  a,  a.  Fungiform 
papillae,     fc.  Filiform  papillae,  with  their  hair-like  processes,     c.  Similar  ones  deprived  of  their 
epithelium.— Magnified  2  diameters. 

B.  Filiform  compound  papillae :  a.  Artery,     v.  Vein.     c.  Capillary  loops  of  the  secondary 
papillae,     b.  Line  of  basement-membrane,     d.  Secondary  papillae,  deprived  of  e,  e,  the  epithe- 
lium,   f.  Hair-like  processes  of  epithelium  capping  the  simple  papillae. — Magnified  25  diame- 
ters,    g.  Separated  nucleated  particles  of  epithelium  magnified  300  diameters. 

1,  2.  Hairs  found  on  the  surface  of  the  tongue.  3,  4,  5.  Ends  of  hair-like  epithelial  pro- 
cesses, showing  varieties  in  the  imbricated  arrangement  of  the  particles,  but  in  all  a  coales- 
cence of  the  particles  towards  the  point.  5  incloses  a  soft  hair. — Magnified  160  diameters,  j 

1  The  Author,  in  conjunction  with  Messrs.  Bowman,  T.  Wharton  Jones,  and  Kiernao, 
has  most  carefully  examined  the  mode  of  termination  of  the  nerves  in  the  fungiform  pa- 
pilla?, with  the  view  of  testing  the  validity  of  the  assertion  of  Dr.  Waller  ("Phil.  Trans?..  ' 
1*49)  that  they  have  free  truncated  extremities.  No  such  terminations,  however  could 
ho  exhibited  to  them  by  Dr.  Waller. 


SENSE    OF    TASTE.  663 

papillae  that  clothe  the  surface  of  the  compound  body;  but  instead  of  being 
covered  with  a  thin  scaly  epithelium,  they  are  furnished  with  bundles  of  long 
pointed  processes,  some  of  which  approach  hairs  in  their  stiffness  and  structure. 
(Fig.  162.)  These  are  immersed  in  the  mucus  of  the  mouth,  and  may  be  moved 
in  any  direction,  though  they  are  generally  inclined  backwards. — The  simple 
papillae  which  occur  in  an  isolated  manner,  may  not  improbably  be  tactile ;  whilst 
those  which  are  aggregated  in  the  circumvallate  and  fungiform  bodies,  doubtless 
minister  to  the  sense  of  Taste,  this  being  most  acute  in  the  situations  wherein  they 
most  abound.  With  regard,  however,  to  the  office  of  the  filiform  papillae,  there 
seems  much  reason  to  coincide  in  the  opinion  of  Messrs.  Todd  and  Bowman  : — 
"The  comparative  thickness  of  their  protective  covering,  the  stiffness  and  brush- 
like  arrangement  of  their  filamentary  productions,  their  greater  development  in 
that  portion  of  the  dorsum  of  the  tongue  which  is  chiefly  employed  in  the  move- 
ments of  mastication,  all  evince  the  subservience  of  these  papillae  to  the  latter 
function,  rather  than  to  that  of  taste ;  and  it  is  evident  that  their  isolation  and 
partial  mobility  on  one  another,  must  render  the  delicate  touch  with  which  they 
are  endowed,  more  available  in  directing  the  muscular  actions  of  the  organ.  The 
almost  manual  dexterity  of  the  organ,  in  dealing  with  minute  particles  of  food, 
is  probably  provided-for,  as  far  as  sensibility  conduces  to  it,  in  the  structure  and 
arrangement  of  these  papillae.  It  may  be  added,  that  the  filiform  papillae  of  Man 
seem  to  be  the  rudimentary  forms  of  those  horny  epithelial  processes,  which  ac- 
quire so  great  a  development  in  the  tongues  of  the  Carnivora,  and  which  are  of 
such  importance  in  the  abrasion  of  their  food. 

742.  The  simple  application  of  a  sapid  substance  to  the  gustative  surface,  is 
usually  sufficient  to  excite  the  sensation ;  and  if  this  application  be  restricted  to 
one  particular  spot,  we  are  able  to  recognize  its  place  more  or  less  distinctly.  In 
this  respect,  then,  the  gustative  impression  resembles  the  tactile ;  for  whilst  we 
cannot,  by  our  own  consciousness,  distinguish  the  parts  of  the  retina  or  of  the 
auditory  apparatus  on  which  visual  or  auditory  impressions  are  made,  we  can 
make  this  distinction  in  regard  to  the  surface  which  is  supplied  by  the  nerves 
of  general  sense.  This  determination  is  most  precise,  when  the  impression  is 
made  on  the  parts  of  the  tongue  of  which  the  gustative  sensibility  is  most  acute, 
namely,  the  apex,  sides,  and  posterior  part  of  the  dorsum ;  being  probably  aided, 
however,  near  the  tip,  by  the  acuteness  of  its  tactile  sensibility.  The  impressi- 
bility of  the  middle  portion  of  the  dorsum  is  greatly  inferior ;  but  still,  when 
the  gustative  sensation  has  been  excited  there,  it  is  referred  to  the  spot  on  which 
the  sapid  substance  was  laid.  The  contact  of  sapid  substances  much  more 
readily  excites  a  gustative  sensation,  when  it  is  made  to  press  upon  the  papillae, 
or  is  moved  over  them.  Thus  there  are  some  substances,  whose  taste  is  not  per- 
ceived when  they  are  simply  applied  to  the  central  part  of  the  dorsum  of  the 
tongue,  but  of  whose  presence  we  are  at  once  rendered  cognizant  by  pressing  the 
tongue  against  the  roof  of  the  mouth.  The  full  flavour  of  a  sapid  substance, 
again,  is  more  readily  perceived  when  it  is  rubbed  on  any  part  of  the  tongue, 
than  when  it  is  simply  brought  in  contact  with  it,  or  pressed  against  it.  Even 
when  liquids  are  received  into  the  mouth,  their  taste  is  most  completely  discrim- 
inated by  causing  them  to  move  over  the  gustative  surface :  thus  the  '  wine- 
taster  '  takes  a  small  quantity  of  the  liquor  into  his  mouth,  carries  it  rapidly  over 
every  part  of  its  lining  membrane,  and  then  ejects  it.  It  is  not  improbable  that 
this  exaltation  of  the  usual  effects  is  simply  due  to  mechanical  causes ;  the  sapid 
particles  being  brought  by  the  pressure  or  movement  into  more  rapid  and  com- 
plete operation  on  the  nerve-fibres,  than  they  would  be  if  simply  placed  in  con- 
tact with  the  papillae. 

743.  The  impressions  made  upon  our  consciousness  by  a  large  proportion  of 
sapid  substances,  are  of  a  complex  kind ;  being  in  part  derived  from  their  odor- 
ous emanations,  of  which  we  take  cognizance  through  the  organ  of  Smell.  Of 
this  any  one  may  convince  himself,  by  closing  the  nostrils,  and  inspiring  and  ex- 


66-1         OF   THE   ORGANS    OF   THE    SENSES,    AND   THEIR   FUNCTIONS. 

piring  through  the  mouth  only,  whilst  holding  in  the  mouth,  or  even  rubbing 
between  the  tongue  and  the  palate,  some  aromatic  substance;  for  its  taste  is  then 
scarcely  recognized,  although  it  is  immediately  perceived  when  its  effluvia  are 
drawn  into  the  nose.  It  is  well  known,  too,  that  when  the  sensibility  of  the 
Schneiderian  membrane  is  blunted  by  inflammation  (as  in  an  ordinary  f  cold  in 
the  head'),  the  power  of  distinguishing  flavours  is  very  much  diminished.  In 
fact,  some  Physiologists  are  of  opinion  that  all  our  knowledge  of  the  flavour  of 
sapid  substances  is  received  through  the  Smell;  but  this,  as  already  shown, 
would  not  be  a  correct  statement;  and  there  are  cases  on  record  which  the  sense 
of  Smell  has  been  entirely  lost,  without  any  impairment  of  the  true  sense  of 
Taste.1 

744.  Taken  in  its  ordinary  composite  acceptation,  the  sense  of  Taste  has  for 
its  object  to  direct  us  in  the  choice  of  food,  and  to  excite  the  flow  of  mucus  and 
saliva,  which  are  destined  to  aid  in  the  preparation  of  the  food  for  Digestion. 
Among  the  lower  Animals,  the  instinctive  perceptions  connected  with  this  sense 
are  much  more  remarkable  than  our  own ;  thus  an  omnivorous  Monkey  will  sel- 
dom touch  fruits  of  a  poisonous  character,  although  their  taste  may  be  agreeable; 
and  animals  whose  diet  is  restricted  to  some  one  kind  of  food,  will  decidedly 
reject  all  others.  As  a  general  rule  it  may  be  stated,  that  substances  of  which 
the  taste  is  agreeable  to  us,  are  useful  in  our  nutrition,  and  vice  versd,;2  but  there 
are  many  signal  exceptions  to  this. — Like  other  senses,  that  of  Taste  is  capable 
of  being  rendered  more  acute  by  education;  and  this  on  the  principles  already 
laid  down  in  regard  to  Touch.  The  experienced  wine-taster  can  distinguish  dif- 
ferences in  age,  purity,  place  of  growth,  &c.,  between  liquors  that  to  ordinary 

1  An  interesting  case  of  this  kind,  occurring  in  a  Negro  who  had  gradually  lost  the  cha- 
racteristic hue  of  his  skin,  and  had  acquired  the  fair  complexion  of  a  European  ($  934), 
has  been  put  on  record  by  Dr.  J.  C.  Hutchinson. — The  Olfactory  nerve  seemed  to  be  en- 
tirely paralysed,  whilst  the  branches  of  the  5th  Pair  retained  their  integrity ;  so  that, 
•whilst  the  proper  sense  of  Smell  was  entirely  lost,  a  pungent  burning  sensation  was  excited 
by  irritating  vapours,  and  the  application  of  snuff  induced  sneezing.     Notwithstanding 
this  deficiency,  the  sense  of  Taste,  properly  so  called,  did  not  seem  to  be  impaired  ;  for 
substances  which  possessed  neither  odour  nor  pungency  could  readily  be  discriminated, 
even  though  their  tastes  were  not  widely  different.     (See  "  Amer.  Journ.  of  Med.  Sci.," 
Jan.  1852.) 

2  It  is  justly  remarked  by  Sir  H.  Holland  ("  Medical  Notes  and  Reflections,"  p.  85), 
that, — "  In  the  majority  of  instances  of  actual  illness,  provided  the  real  feelings  of  the 
patient  can  be  safely  ascertained,  his  desires  as  to  food  and  drink  may  be  safely  complied- 
with.     But  undoubtedly  much  care  is  needful  that  we  be  not  deceived  as  to  the  state  ol 
the  appetites,  by  what  is  merely  habit  or  wrong  impression  on  the  part  of  the  patient,  or 
the  effect  of  the  solicitation  of  others.     This  class  of  sensations  is  more  nurtured  out  of 
the  course  of  nature,  than  are  those  which  relate  to  the  temperature  of  the  body.     The 
mind  becomes  much  more  deeply  engaged  with  them  ;  and  though  in  acute  illness  they  are 
generally  submitted  again  to  the  natural  law,  there  are  many  lesser  cases  where  enough 
remains  of  the  leaven  of  habit  to  render  every  precaution  needful.    With  such  precautions, 
however,  which  every  physician  who  can  take  schooling  from  experience  will  employ,  the 
stomach  of  the  patient  becomes  a  valuable  guide :  whether  it  dictates  abstinence  from  a 
recurrence  of  food ;  whether  much  or  little  in  quantity ;  whether  what  is  solid  or  liquid  ; 
whether  much  drink  or  little ;  whether  things  warm  or  cold ;  whether  sweet,  acid,  or 
Baline ;  whether  bland  or  stimulating  to  the  taste."     Further,  Sir  H.  Holland  remarks: 
"It  is  not  wholly  paradoxical  to  say  that  we  are  authorized  to  give  greatest  heed  to  the 
Btomach,  when  it  suggests  some  seeming  extravagance  of  diet.     It  may  be  that  this  is  a 
mere  depravation  of  the  sense  of  taste ;  but  frequently  it  expresses  an  actual  need  of  the 
Btomach,  either  in  aid  of  its  own  functions,  or  indirectly  (under  the  mysterious  law  just 
referred-to)  for  the  effecting  of  changes  in  the  whole  mass  of  blood.     It  is  a  good  practical 
rule  in   such  cases  to  withhold  assent,  till  we  find  after  a  certain  lapse  of  time  that  the 
same  desire  continues  or  strongly  recurs ;  in  which  case  it  may  generally  be  taken  as  the 
index  of  the  fitness  of  the  thing  desired  for  the  actual  state  of  the  organs.     In  the  early 
stage  of  recovery  from  long  gastric  fevers,  I  recollect  many  curious  instances  of  such  con- 
trariety to  all  rule  being  acquiesced-in,  with  manifest  good  to  the  patient.     Dietetics  must 
become  a  much  more  exact  branch  of  knowledge,  before  we  can  be  justified  in  opposing  its 
maxims  to  the  natural  and  repeated  suggestions  of  the  stomach,  in  the  state  either  of 
health  or  disease." 


SENSE    OF    SMELL.  665 

judgments  are  alike ;  and  the  epicure  can  give  an  exact  determination  of  the 
spices  that  are  combined  in  a  particular  sauce,  or  of  the  manner  in  which  the 
animal,  on  whose  flesh  he  is  feeding,  was  killed.  As  in  the  case  of  other  senses; 
moreover,  impressions  made  upon  the  sensory  surface  remain  there  for  a  certain 
period ;  and  this  period  is  for  the  most  part  longer  than  that  which  is  required 
for  the  departure  of  the  impressions  made  upon  the  eye,  the  ear,  or  the  organ  of 
smell.  Every  one  knows  how  long  the  taste  of  some  powerful  substances  remains 
in  the  mouth ;  and  even  of  those  which  make  less  decided  impressions,  the  sen- 
sations remain  to  such  a  degree  that  it  is  difficult  to  compare  them  at  short  inter- 
vals. Hence  if  a  person  be  blindfolded,  and  be  made  to  taste  substances  of 
distinct,  but  not  widely-different  flavours  (such  as  various  kinds  of  wine  or  of 
spirituous  liquors),  one  after  another  in  rapid  succession,  he  soon  loses  the  power 
of  discriminating  between  them.  In  the  same  manner,  the  difficulty  of  admin- 
istering very  disagreeable  medicines  may  be  sometimes  got-over,  by  either  pre- 
viously giving  a  powerful  aromatic,  or  by  combining  the  aromatic  with  the 
medicine ;  its  strong  impression  in  both  cases  preventing  the  unpleasant  taste 
from  exciting  nausea. 

4.— Sense  of  Smell 

745.  The  Nasal  passages  may  be  considered  as  having,  in  air-breathing  Verte- 
brata,  two  distinct  offices ;  for  they  constitute  the  portal  of  the  Respiratory  organs, 
and  have  for  their  office  to  take  cognizance  of  the  aeriform  matter  as  it  enters 
them,  and  to  give  warning  of  that  which  would  be  injurious  (this  being  effected 
by  the  instrumentality  of  the  Fifth  pair,  which  receives  the  impressions  of  gaseous 
irritants,  and  excites  the  act  of  sneezing  to  expel  them,  (§  520)  ;  whilst  they  also 
contain  the  organ  of  Smell,  which  is  formed  by  the  distribution,  over  a  certain 
part  of  their  membranous  wall,  of  the  Olfactory  nerve,  which  is  susceptible  of 
being  impressed  by  Odorous  emanations.     Of  the  nature  of  these  emanations,  the 
Natural  Philosopher  is  so  completely  ignorant,  that  the  Physiologist  cannot  be 
expected  to  give  a  definite  account  of  the  mode  in  which  they  produce  sensory 
impressions.     Although  it  may  be  surmised  that  they  consist  of  particles  of  ex- 
treme minuteness,  dissolved  as  it  were  in  the  air,  and  although  this  idea  seems  to 
derive  confirmation  from  the  fact  that  most  odorous  substances  are  volatile,  and 
vice  versa, — yet  the  most  delicate  experiments  have  failed  to 

discover  any  diminution  in  weight,  in  certain  substances  (as          Fio.  163. 
musk)  that  have  been  impregnating  a  large  quantity  of  air 
with  their  effluvia  for  several  years;  whilst  there  are  some  vola- 
tile fluids,  such  as  water,  which  are  entirely  inodorous. 

746.  The   Olfactory  nerves  pass-down  from  the  Olfactory 
Ganglion  (§  517)  in  the  form  of  very  numerous  minute  threads, 
which  form  a  plexus  upon  the  surface  of  the  Schneiderian  or 
pituitary  membrane  (Fig.  164).     The  filaments  composing  this 
plexus  are  described  by  Messrs.  Todd  and  Bowman1  as  differ- 
ing widely  in  structure  from   those  of  the  ordinary  cephalic 
nerves ;  they  contain  no  white  substance  of  Schwann,  are  nu- 
cleated and  finely-granular  in  texture,  and  altogether  bear  a 
close  resemblance  to  the  gelatinous  form  of  nerve-fibres  (Fig. 
163).     It  has  been  hitherto  found  impossible  to  trace  the  ul- 
timate distribution  of  these  fibres  in  the  olfactory  membrane, 

owing  to  their  want  of  the  characteristic  white  substance,  and      Fibres  of  ultimate 
the  absence  of  distinction  between  the  nuclei  of  the  minuter  ramifications  of  01- 
fibres  and  those  of  the  nucleated  tissues  through  which  they  factory  Nerve  of  Dog. 
pass;  but  it  seems  limited    to   the   membrane  covering  the 
superior  three-fourths  of  the  septum  of  the  nose,  the  superior  turbinated  bon« 

1  "  Physiological  Anatomy,"  p.  397,  Am.  Ed. 


66'j      OF    THE    ORGANS     OF    THU    SENSES,     AND    THEIR    FUNCTIONS. 


Distribution  of  the  Olfactory  Nerve  on  the  Septum  Nasi.  The  nares  have  been  divided  by 
a  longitudinal  section  made  immediately  to  the  left  of  the  septum,  the  right  nares  being  pre- 
served entire. — 1.  The  frontal  sinus.  2.  The  nasal  bone.  3.  The  crista  galli  process  of  the 
ethmoid  bone.  4.  The  sphenoidal  sinus  of  the  left  side.  5.  The  sella  turcica.  6.  The  basi- 
lar  process  of  the  sphenoidal  and  occipital  bones.  7.  The  posterior  opening  of  the  right 
nares.  8.  The  opening  of  the  Eustachian  tube  in  the  upper  part  of  the  pharynx.  9.  The 
soft  palate,  divided  through  its  middle.  10.  Cut  surface  of  the  hard  palate,  a.  The  olfac- 
tory peduncle,  b.  Its  three  roots  of  origin,  c.  Olfactory  ganglion,  from  which  the  filaments 
proceed  that  spread-out  in  the  substance  of  the  pituitary  membrane,  d.  The  nasal  nerve,  a 
branch  of  the  ophthalmic  nerve,  descending  into  the  left  nares  from  the  anterior  foramen  of 
the  cribriform  plate,  and  dividing  into  its  external  and  internal  branch,  e.  The  naso-pala- 
tine  nerve,  a  branch  of  the  spheno-palatine  ganglion,  distributing  twigs  to  the  mucous  mem- 
brane of  the  septum  nasi  in  its  course  to  (/)  the  anterior  palatine  foramen,  where  it  forms  a 
small  gangliform  swelling  (Cloquet's  ganglion)  by  its  union  with  its  fellow  of  the  opposite 
side.  g.  Branches  of  the  naso-palatine  nerve  to  the  palate,  h.  Posterior  palatine  nerves. 
i,  i.  The  septum  nasi. 

and  the  upper  half  of  the  middle  turbinated  bone,  and  the  upper  wall  of  the  nasal 
cavities  beneath  the  cribriform  plate  of  the  ethmoid  bone ;  all  which  surface  is 
covered  (as  Messrs.  Todd  and  Bowman  have  pointed-out)  with  a  tesselated  epi- 
thelium of  a  rich  sepia-brown  hue.  The  remainder  of  the  nasal  surface  is  sup- 
plied by  the  Fifth  pair  only,  and  is  not  endowed  with  sensibility  to  odours, 
although  it  is  susceptible  of  irritation  from  such  as  are  of  a  pungent  nature ;  and 
hence  it  is  that  we  cannot  distinguish  faint  odours,  unless,  by  a  peculiar  inspi- 
ratory  effort,  we  draw  the  air  charged  with  them  to  the  upper  part  of  the  nose. 
In  animals  living  in  the  air,  it  is  a  necessary  condition  of  the  exercise  of  the  sense 
of  Smell,  that  the  odorous  matter  should  be  transmitted  by  a  respiratory  current 
through  the  nostrils,  and  that  the  membrane  lining  these  should  be  in  a  moib-t 
state.  Hence,  by  breathing  through  the  mouth,  we  may  avoid  being  affected  by 
odours  even  of  the  strongest  and  most  disagreeable  kind ;  and  in  the  first  state  of 
a  catarrh,  when  the  ordinary  mucous  secretion  is  suspended,  the  sense  of  Smell 
is  blunted  from  this  cause,  as  it  afterwards  is  from  the  excess  in  the  quantity  of 
the  fluid,  which  prevents  the  odoriferous  effluvia  from  coming  into  immediate  re- 
lation with  the  sensory  extremities  of  the  nerves.  Hence  we  may  easily  compre- 
hend how  section  of  the  Fifth  Pair,  which  exerts  a  considerable  influence  over  the 
secretions,  will  greatly  diminish  the  acuteness  of  this  sense,  and  will  have  the  fur- 
ther effect  of  preventing  the  reception  of  any  impressions  of  irritation  from  acrid 
vapours,  which  are  entirely  different  in  their  character  from  true  odorous  impres- 
sions, and  are  not  transmitted  through  the  Olfactory  nerve  (§  520). 


SENSE     OF    VISION.  607 

747.  The  importance  of  the  sense  of  Smell  among  many  of  the  lower  Animals, 
in  guiding  them  to  their  food,  or  in  giving  them  warning  of  danger,  and  also  in 
exciting  the  sexual  feelings,  is  well  known.     To  Man  its  utility  is  comparatively 
small  under  ordinary  circumstances;  but  it  may  be  greatly  increased  when  other 
senses  are  deficient.     Thus,  in  the  well-known  case  of  James  Mitchell,  who  was 
blind,  deaf,  and  dumb,  from  his  birth,  it  was  the  principal  means  of  distinguish- 
ing persons,  and  enabled  him  at  once  to  perceive  the  entrance  of  a  stranger.     It 
is  recorded  that  a  blind  gentleman,  who  had  an  antipathy  to  cats,  was  possessed  of 
a  sensibility  so  acute  in  this  respect,  that  he  perceived  the  proximity  of  one  that 
had  been  accidentally  shut-up  in  a  closet  adjoining  his  room.     Among  Savage 
tribes,  whose  senses  are  more  cultivated  than  those  of  civilized  nations,  more 
direct  use  being  made  of  the  powers  of  observation,  the  scent  is  almost  as  acute 
as  in  the  lower  Mammalia :  thus  it  is  asserted  by  Humboldt,  that  the  Peruvian 
Indians  in  the  middle  of  the  night  can  distinguish  the*  different  races,  whether 
European,  American-Indian,  or  Negro;  and  the  Arabs  of  the  Great  Desert  are 
said  to  be  able  to  distinguish  the  smell  of  a  fire  thirty  miles  ofT. — The  agreeable 
or  disagreeable  character  assigned  to  particular  odours,  is  by  no  means  constant 
amongst  different  individuals.     Just  as  many  of  the  lower  Animals  pass  their 
whole  lives  in  the  midst  of  odours  that  are  to  Man  (in  his  civilized  condition  at 
least)  in  the  highest  degree  revolting,  and  will  even  refuse  to  touch  food  until  it 
is  far  advanced  in  putridity,  so  do  we  find  that  men  who  are  compelled  by  cir- 
cumstances to  live  upon  putrescent  food,  come  at  last  to  relish  it  most  when  it  is 
furthest  advanced  in  decomposition  (§  62);  and  the  most  refined  epicures  among 
highly-civilized  communities  seem  to  find  pleasure  in  similar  odours  and  savours, 
which,  to  ordinary  tastes,  are  anything  but  agreeable. — As  to  the  length  of  time 
during  which  impressions  made  upon  the  organ  of  Smell  remain  upon  it,  no  cer- 
tain knowledge  can  be  obtained.     It  is  difficult  to  say  when  the  effluvia  them 
selves  have  been  completely  removed  from  the  nasal  passages,  since  it  is  not 
unlikely  that  the  odorous  particles  (supposing  such  to  exist)  are  absorbed  or  dis- 
solved  by  the  mucous  secretion ;   it  is  probably  in  this  manner  that  we  may 
account  for  the  fact,  well  known  to  every  medical  man,  that  the  cadaverous  odour 
is  frequently  experienced  for  many  days  after  a  post-mortem  examination.1 

5. — Sense  of  Vision. 

748.  The  objects  of  this  sense  are  bodies  from  which  Light  proceeds,  either 
because  they  are  luminous  in  themselves,  or  because  they  reflect  the  light  that 
proceeds  from  other  bodies.     Whether  their  light  is  transmitted  by  the  actual 
emission  of  luminous  particles,  or  by  the  propagation  of  undulations  analogous 
to  those  of  sound,  is  a  question   that  has  been  long  keenly  debated  amongst 
Natural  Philosophers  ;    but  it  is  of  little  consequence*  to  the  Physiologist  which 
is  the  true  solution,  since  he  is  only  concerned  with  the  laws  according  to  which 
the  transmission  takes  place,  which  are  the  same  on  both  theories.     These  laws 
it  may  be  desirable  here  briefly  to  recapitulate. 

749.  Every  point  of  a  luminous  body  sends-off  a  number  of  rays,  which  diverge 
in  every  direction,  so  as  to  form  (as  it  were)  a  cone,  of  which  the  luminous  point 
is  the  apex.     So  long  as  these  rays  pass  through  a  medium  of  the  same  density, 
they  proceed  in  straight  lines;  but  if  they  enter  a  medium  of  different  density, 
they  are  refracted  or  bent, — towards  the  perpendicular  to  the  surface  at  the 
point  at  which  they  enter,  if  they  pass  from  a  rarer  into  a  denser  medium, — and 
from  the  perpendicular,  when  they  pass  from  a  denser  medium  into  a  rarer.     It 
is  easily  shown  to  be  a  result  of  this  law,  that,  when  parallel  rays  passing  through 
air  fall  upon  a  convex  surface  of  glass,  they  will  be  made  to  converge ;  so  as  to 
meet  at  the  opposite  extremity  of  the  diameter  of  the  circle,  of  which  the  curve 

1  This  may  partly  be  attributed  also  to  the  effluvia  adhering  to  the  dress.     It  has  been 
remarked  that  dark  cloths  retain  these  more  strongly  than  light. 


668          OF   THE    ORGANS    OF   THE    SENSES    AND    THEIR    FUNCTIONS. 

forms  part.  If,  instead  of  continuing:  in  the  glass,  they  pass-out  again,  through 
a  second  convex  surface,  of  which  the  direction  is  the  reverse  of  the  first,  they 
will  be  made  to  converge  still  more,  so  as  to  meet  in  the  centre  of  curvature. 
Rays  which  are  not  parallel,  but  which  are  diverging  from  a  focus,  are  likewise 
made  to  converge  to  a  point  or  focus;  but  this  point  will  be  more  distant  from 
the  lens,  in  proportion  as  the  object  is  nearer  to  it,  and  the  angle  of  divergence 
consequently  greater.  The  rays  diverging  from  the  several  points  of  a  luminous 
object,  are  thus  brought  to  corresponding  foci ;  and  the  places  of  all  these  foci 
hold  exactly  the  same  relation  to  each  other,  with  that  of  the  points  from  which 
the  rays  diverged  ;  so  that  a  perfect  image  of  the  object  is  formed  upon  a  screen 
held  in  the  focus  of  the  lens.  This  image,  however,  will  be  inverted;  and  its 
size,  in  proportion  to  that  of  the  object,  will  depend  upon  their  respective  dis- 
tances from  the  lens.  If  their  distances  be  the  same,  their  size  will  also  be  the 
same ;  if  the  object  be  Distant,  and  the  image  near,  the  latter  will  be  much  the 
smaller  :  and  vice  versd. 

750.  There  are  two  circumstances,  however,  which   interfere  with  the  per- 
fection of  an  image  thus  formed  by  a  convex  lens.     The  one  is,  that,  if  the  lens 
constitute  a  large  part  of  the  sphere  from  which  it  is  taken,  the  rays  which  fall 
near  its  margin  are  not  brought  to  a  focus  at  the  same  point  with  those  which 
pass  through  its  centre,  but  at  a  point  nearer  the  lens.     This  difference,  which 
must  obviously  interfere  greatly  with  the  distinctness  of  the  image,  is  termed 
Spherical  Aberration ;  it  may  be  corrected  b}'  the  combination  of  two  or  more 
lenses,  of  which  the  curvatures  are  calculated  to  balance  one  another,  in  such  a 
manner  that  all  the  rays  shall  be  brought  to  the  same  focus ;  or  by  diminishing 
the  aperture  of  the  lens  by  means  of  a  stop  or  diaphragm,  in  such  a  manner  that 
only  the  central  part  of  it  shall  be  used.     The  latter  of  these  methods  is  the  one 
employed,  where  the  diminution  in  the  amount  of  light  transmitted  is  not  attended 
with  inconvenience.     The  nearer  the  object  is  to  the  lens  (and  the  greater,  there- 
fore, the  angle  of  divergence  of  its  rays),  the  greater  will  be  the  spherical  aberra- 
tion, and  the  more  must  the  aperture  of  the  diaphragm  be  reduced  in  order  to 
counteract  it. — The  other  circumstance  that  interferes  with  the  distinctness  of 
the  image,  is  the  unequal  refrangibility  of  the  differently-coloured  rays,  which 
together  make-up  white  or  colourless  light;  the  violet  being  more  bent  from  their 
course  than  the  blue,  the  blue  more  than  the  yellow,  and  the  yellow  more  than 
the  red  ;  the  consequence  of  which  will  be,  that  the  violet  rays  are  brought  to  a 
focus  much  nearer  to  the  lens  than  the  blue,  and  the  blue  nearer  than  the  red. 
If  a  screen  be  held  to  receive  the  image  in  the  focus  of  any  of  the  rays,  the  others 
will  make  themselves  apparent  as  fringes  round  its  margin.     This  difference  is 
termed  Chromatic  Aberration.     It  is  corrected  in  practice,  by  combining  together 
lenses  of  different  substances,  of  which  the  dispersive  power  (that  is,  the  power 
of  separating  the  coloured  rays)  differs  considerably.     This  is  the  case  with  flint 
and  crown-glass,  for  instance, — the  dispersive  power  of  the  former  being  much 
greater  than  that  of  the  latter,  whilst  its  refractive  power  is  nearly  the  same  :  so 
that,  if  a  convex  lens  of  crown-glass  be  united  with  a  concave  of  flint  whose  curva- 
ture is  much  less,  the  dispersion  of  the  rays  effected  by  the  former  will  be  entirely 
counteracted  by  the  latter,  which  diminishes  in  part  only  its  refractive  power. 

751.  The  Eye  may  be  regarded  as  an  optical  instrument  of  great  perfection, 
adapted  to  produce,  on  the  surface  of  the  Retina,  a  complete  image  or  picture  of 
luminous  objects  brought  before  it;  in  which  the   forms,  colours,  lights   and 
shades,  &c.  of  the  object  are  all  accurately  represented.     By  the  different  refrac- 
tive powers  of  the  transparent  media  through  which  the  rays  of  light  pass,  and 
by  the   curvatures  given  to  their  respective  surfaces,  both  the  Spherical  and 
Chromatic  aberrations  are  corrected  in  a  degree  sufficient  for  all  practical  pur- 
poses ;  so  that  in  a  well-formed  eye,  the  picture  is  quite  free  from  haziness  and 
from  false  colours.     The  power  by  which  it  adapts  itself  to  variations  in  .the  dis- 
tance of  the  object, — so  as  to  form  a  distinct  image,  of  it,  whether  it  be  six 


SENSE    OF    VISION!  —  OPTICAL    PRINCIPLES.  6C9 

inches,  six  yards,  or  six  miles  off, — is  extremely  remarkable,  and  cannot  be  re- 
garded as  hitherto  completely  explained.  It  is  obvious  that,  if  we  fix  upon  any 
distance  as  that  for  which  the  eye  is  naturally  adjusted  (say  12  or  14  inches,  the 
distance  at  which  we  ordinarily  read),  the  rays  proceeding  from  an  object  placed 
nearer  to  the  eye  than  this,  would  not  be  brought  to  a  focus  upon  the  retina,  but 
would  converge  towards  a  point  behind  it ;  whilst,  on  the  contrary,  the  rays  from 
an  object  at  a  greater  distance  would  meet  before  they  reach  the  retina,  and 
would  have  again  diverged  from  each  other  when  they  impinge  upon  it;  so  that, 
in  either  case,  vision  would  be  indistinct.  Now  two  methods  of  adaptation  sug- 
gest themselves  to  the  Optician.  Either  he  may  vary  the  distance  between  the 
refracting  surface  and  the  screen  on  which  the  image  is  formed,  in  such  a  man- 
ner that  the  latter  shall  always  be  in  the  focus  of  the  converging  rays ;  or,  the 
distance  of  the  screen  remaining  the  same,  he  may  vary  the  convexity  of  his  lens, 
in  such  a  manner  as  to  adapt  it  to  the  distance  of  the  object. — The  mode  in  which 
this  adaptation  is  effected  in  the  Human  Eye  has  not  yet  been  clearly  made-out ; 
and  many  hypotheses  have  been  put  forward  respecting  it.  According  to  the 
calculations  of  Gibers,  based  on  the  ascertained  refractive  powers  of  the  media  of 
the  eye,  the  difference  between  the  focal  distances  of  the  images  of  two  objects5 
the  one  so  far  off  that  its  rays  are  parallel,  and  the  other  at  the  distance  of  only 
four  inches  from  the  .eye,  is  about  0-143  or  one-seventh  of  an  inch  ;  but  as  th« 
usual  range  of  distinct  vision  does  not  extend  to  objects  brought  within  six  or 
seven  inches,  the  amount  of  change  required  in  the  relative  places  of  the  refract- 
ing bodies  and  the  retina,  would  not  ordinarily  exceed  a  line.  It  has  been 
thought  that  this  change  might  be  produced  by  an  alteration  in  the  convexity  of 
the  cornea,  or  by  an  elongation  of  the  globe  of  the  eye  generally,  or  by  both 
methods  in  combination ;  which  alterations,  it  was  supposed,  might  be  effected 
by  the  action  of  the  muscles  of  the  eye-ball.  But  no  such  changes  have  been 
detected  by  the  most  careful  measurement ;  and  it  can- 
not be  shown  how  any  contractile  action  of  the  muscles  EFlG- 165< 
of  the  eye-ball  could  produce  an  elongation  of  the  eye, 
since  their  tendency  would  be  (when  acting  altogether) 
to  draw  it  backwards  into  its  socket,  or,  this  being 
prevented  by  the  fascia  and  cushion  of  fat  against 
which  its  posterior  side  rests,  to  flatten  the  globe 
against  this,  rather  than  to  increase  its  projection. 
There  is  much  more  ground  for  the  belief,  however, 
that  a  change  of  place  is  effected  in  the  crystalline  lens, 
by  the  action  of  the  ciliary  muscle  (Fig.  165)  and  the  erec- 
tile tissue  of  the  ciliary  processes ;  for,  although  no 
such  change  can  be  demonstrated  by  observation,  yet  it 
can  be  shown  that  the  contraction  of  the  ciliary  muscle 
would  tend  to  draw  the  lens  forwards ;  and  the  fact  that  Muscle :  a.  Sclerotic.  &.  Cor- 
this  muscle  is  peculiarly  powerful  in  the  predaceous  nea.  c.  Choroid,  separated 
Birds,  which  are  distinguished  for  their  great  range  of  a  little  from  the  sclerotic,  d. 
vision,  and  which  have  in  their  circle  of  osseous  scle-  Situation  of  the  ciliary  liga- 
rotic  plates,  an  unusually  firm  point  of  attachment  for  r^±^t^ 
it,  is  a  strong  argument  in  favour  of  this  doctrine,  b  ur-  iris.  „.  Lens,  connected  with 
ther,  the  almost  entire  loss  of  the  power  of  adapting  the  the  ciliary  processes  by  the 
eye  to  distances,  which  is  experienced  after  the  removal  anterior  wall  of  the  canal  of 
of  the  Crystalline  lens  in  the  operation  for  Cataract,  is  a 
marked  indication  that  some  change  in  the  place  or 
figure  of  this  body  is  the  principal  means  whereby  the 
ordinary  adaptation  is  effected ;  and  although  it  has  been  suggested  that  an  al- 

1  See  on  this  subject,  Messrs.  Todd  and  Bowman's  "Physiological  Anatomy,"  p.  412 
Am.  Ed. ;  and  Dr.  Clay  Wallace  on  "The  Adjustment  of  the  Eye  to  distances,"  'New  YorK, 
1851. 


670         OF   THE   ORGANS    OF   THE    SENSES    AND    THEIR    FUNCTIONS. 

(ft 

teration  in  the  figure  of  the  lens  might  participate  in  the  result,  yet  no  means  can 
be  pointed-out  as  competent  to  produce  it ;  so  that,  as  far  as  we  can  at  present 
judge,  a  change  in  the  place  of  the  lens  is  the  sole  means  of  adapting  the  eye 
to  the  distinct  vision  at  varying  distances. — It  is  certain  that  the  condition  of 
repose  is  that  of  vision  for  distant  objects,  no  fatigue  being  experienced  from  the 
prolonged  direction  of  the  eye  to  these ;  whilst  the  employment  of  the  visual 
power  upon  near  objects  for  some  time,  is  accompanied  with  a  sense  of  effort, 
and  is  followed  by  fatigue.  The  movement  which  effects  the  change  of 
place  of  the  crystalline  lens,  is  performed  in  obedience  to  Volition  and  is  guided 
by  sensation ;  yet  we  are  not  conscious  of  performing  it,  all  that  we  will  being 
the  result ;  and  thus  we  have  another  apposite  illustration  of  the  really  automatic 
nature  of  what  are  termed  l  voluntary  movements'  generally  (§  548). 

752.  When  both  eyes  are  fixed  upon  an  object,  their  axes  converge  so  as  to 
meet  in  it;  and  the  degree  of  convergence  is  of  course  altered  by  variations  in 
the  distance  of  the  object ;  since,  when  the  object  is  very  remote,  the  optic  axes 
are  virtually  parallel,  whilst  its  approach  causes  them  to  incline  towards  each 
other,  and  this  the  more  rapidly  as  the  object  is  brought  nearer,  the  increase  being 
the  greatest  when  it  has  arrived  within  the  ordinary  distance  of  distinct  vision. 
Here,  again,  we  have  an  example  of  the  automatic  nature  of  voluntary  actions  ; 
for  the  convergence  of  the  eyes  that  may  be  produced  by  this  gradual  approxi- 
mation of  an  object  on  which  the  eyes  are  kept-fixed  by  an  exercise  of  the  Will, 
far  exceeds  that  which  most  individuals  can  induce  by  an  effort  made  directly  for 
the  purpose ;  and  if,  when  an  object  has  thus  been  gradually  approximated  to 
within  a  few  inches  of  the  nose,  the  voluntary  fixation  be  intermitted  an.d  the 
optic  axes  be  allowed  to  regain  their  parallelism,  they  can  seldom  be  brought  to 
converge  again    upon  it,  without   repeating   the  whole   process. — It  has  been 
thought,  from  the  close  accordance  between  the  changes  required  for  the  adapta- 
tion of  the  eyes  to  distinct  vision  at  different  distances,  and  the  alterations  in  the 
direction  of  the  optic  axes  which  are  required  to  bring  the  two  eyes  to  bear  upon 
objects  at  varying  degrees  of  proximity  or  remoteness,  that  the  former  of  these 
movements  is  in  some  degree  dependent  upon  the  latter,  or,  at  any  rate,  that  the 
two  proceed  from  a  common  motor  impulse.     But  that  the  convergence  of  the 
axes  is  not  itself  in  any  way  the  occasion  of  the  alteration  of  the  focus  of  the 
eye,  is  shown  by  these  two  facts;  first,  that  the  adaptation  is  as  perfect  in  a 
person  who  only  possesses  or  uses  one  eye,  as  it  is  when  both  are  employed ; 
and  second,  that  some  persons  possess  the  power  of  altering  the  focus  of  the 
eyes  by  an  effort  of  the  will,  whilst  the  convergence  remains  the  same. — In 
regard  to  the  adaptation  of  the  eyes  to  varying  distances,  it  is  further  to  be 
remarked,  that,  when  an  object  is  being  viewed  as  near  to  the  eye  as  it  can  be 
distinctly  seen,  the  pupil  contracts  in  a  considerable  degree.     The  purpose  of  this 
change,  is  evidently  to  exclude  the  outer  rays  of  the  cone  or  pencil,  which,  from 
the  large  angle  of  their  divergence,  would  fall  so  obliquely  on  the  convex  sur- 
face of  the  eye  as  to  be  much  affected  by  the  spherical  aberration,  and  thus  to 
allow  the  central  rays  only  to  enter  the  eye,  so  as  to  preserve  the  clearness  of  the 
image;    the  principle  being  exactly  the   same  as  that  on  which    the   optician 
applies  a  stop  behind  his  lenses,  which  reduces  their  aperture  in  proportion  to 
the  shortness  of  their  focal  distance.     The  channel  through  which  this  action  is 
effected,  is  evidently  the  same  as  that  through  which  the  convergence  of  the  eyes 
is  produced, — namely,  the  inferior  branch  of  the  Third  pair  of  nerves;  to  the 
action  of  which,  the  sensations  received  through  the  retina  seem  to  afford  the 
immediate  stimulus,  hi  the  same  manner  as  they  do  to  the  ordinary  variation 
in  the  diameter  of  the  pupil  under  the  influence  of  light;  but  the  voluntary 
determination  to  fix  the  vision  upon  the  object,  is  the  original  source  of  the 
action. 

753.  The  ordinary  forms  of  defective  vision,  which  are  known  under  the 
names  of  Myopia  and  Presbyopia,  or  'short-sightedness'  and  'long-sightedness/ 


SENSE    OF    VISION!  —  STRUCTURE    OF    RETINA.        671 

are  entirely  attributable  to  defects  in  the  optical  adaptation  of  the  eye.  In  the 
former,  its  refractive  power  is  too  great;  the  rays  from  objects  at  the  usual  dis- 
tance are  consequently  brought  too  soon  to  a  focus,  so  as  to  cross  one  another 
and  diverge  before  they  fall  upon  the  retina;  whilst  the  eye  is  adapted  to  bring 
to  their  proper  focus  on  the  retina,  only  those  rays  which  were  previously  diverg- 
ing at  a  large  angle,  from  an  object  in  its  near  proximity.  Hence  a  ( short- 
sighted' person,  whose  nearest  limit  of  distinct  vision  is  not  above  half  that  of 
a  person  of  ordinary  sight,  can  see  minute  objects  more  clearly ;  his  eyes  having 
in  fact  the  same  magnifying  power  which  those  of  the  other  would  possess,  if 
aided  by  a  convex  glass  that  would  enable  him  to  see  the  object  distinctly  at  the 
shortest  distance.  But  as  the  myopic  structure  of  the  eye  incapacitates  its 
possessor  from  seeing  objects  clearly  at  even  a  moderate  distance,  it  is  desirable 
to  apply  a  correction ;  and  this  is  done,  by  simply  interposing  between  the  object 
and  the  eye  a  concave  lens,  of  which  the  curvature  is  properly  adapted  to  compen- 
sate for  the  excess  of  that  of  the  organ  itself. — On  the  other  hand,  in  the 
presbyopic  eye,  the  curvature  and  refractive  power  are  not  sufficient  to  bring  to 
a,  focus,  on  the  retina,  rays  which  were  previously  divergent  in  a  considerable  or 
even  in  a  moderate  degree;  and  indistinct  vision  in  regard  to  all  near  objects  is, 
therefore,  a  necessary  consequence,  whilst  distant  objects  are  well  seen.  This 
defect  is  remedied  by  the  use  of  convex  lenses  which  make-up  for  the  deficiency  of 
the  curvature. — We  commonly  meet  with  myopia  in  young  persons,  and  with 
presbyopia  in  old ;  but  this  is  by  no  means  the  invariable  rule  ;  for  even  aged  per- 
sons are  sometimes  '  short-sighted/  and  <  long-sightedness'  is  occasionally  met-with 
amongst  the  young.  In  choosing  spectacles  for  the  purpose  of  correcting  the 
errors  of  the  eye,  it  is  of  great  consequence  not  to  make  an  over-compensation ; 
fur  this  has  a  tendency  to  increase  the  defect,  besides  occasioning  great  fatigue 
in  the  employment  of  the  sight.  It  may  be  easily  found  when  a  glass  of  the 
right  power  has  been  selected,  by  inquiring  of  the  individual  whether  it  alters 
the  apparent  size  of  the  objects,  or  only  renders  them  distinct.  If  it  alter  the 
size  (increasing  it,  if  it  be  a  convex  lens,  and  diminishing  it,  if  it  be  a  concave),  its 
curvature  is  too  great;  whilst  if  it  do  not  disperse  the  haze,  it  is  not  sufficiently 
powerful.  In  general  it  is  better  to  employ  a  glass  which  somewhat  under-com- 
pensates  the  eye,  than  one  whose  curvature  is  at  all  too  high;  since,  with  the 
advance  of  years  in  elderly  persons,  a  progressive  increase  in  power  is  required ; 
whilst,  as  young  persons  grow-up  to  adult  age,  they  should  endeavour  to  dispense 
with  the  aid  of  spectacles. — Many  other  interesting  inquiries,  respecting  the 
action  of  the  Eye  as  an  optical  instrument,  suggest  themselves  to  the  Physical 
philosopher;  but  the  foregoing  are  the  chief  in  which  the  Physiologist  is  con- 
cerned; and  we  shall  now  proceed,  therefore,  to  consider  the  share  which  the 
Nervous  apparatus  performs  in  the  phenomena  of  vision. 

754.  The  Optic  Nerve,  at  its  entrance  into  the  eye,  divides  itself  into  numerous 
small  fasciculi  of  ultimate  fibrils ;  and  these  appear  to  spread  themselves  out, 
and  to  inosculate  with  each  other  by  an  exchange  of  fibrils,  so  as  to  form  a  net- 
like  plexus,  which  constitutes  the  inner  layer  of  the  Retina  (Fig.  164,  7)  in  im- 
mediate contact  with  the  *  limitary  membrane/  (8).  There  is  considerable 
difficulty,  however,  in  the  precise  determination  of  the  course  of  the  nerve-fibres 
in  the  lletina,  on  account  of  their  minute  size  and  the  alteration  in  their  char- 
acters. Although  uniformly  much  smaller  than  ordinary  nerve-fibres,  they 
present  considerable  diversities  in  size  (Fig.  167,  1,  2);  the  largest  of  them 
being  only  about  1-QOOOth  of  an  inch  in  diameter,  whilst  the  smallest  are  no 
more  than  from  l-30,000th  to  l-50,000th  of  an  inch.  Notwithstanding  the 
statement  of  Prof.  Kolliker,  that  they  closely  resemble  the  finest  nerve-tubes  in 
the  central  organs,  he  has  not  been  able  to  demonstrate  their  tubular  character; 
and  it  is  considered  by  Mr.  Bowman  that,  like  the  fibres  of  the  Olfactive  tract 
(§  746),  they  consist  of  axis-cylinders  without  sheaths.  Perhaps  the  fact  may 
rtither  be,  that  they  are  in  that  early  stage  of  development,  in  which  the  com- 


672         OF  THE   ORGANS   OF  THE   SENSES,    AND   THEIR   FUNCTIONS. 

ponents  of  a  complete  tubular  fibre  have  not  yet  been  differentiated. — Exter- 
nally to  the  stratum  of  nerve-fibres,  which  may  be  called  the  Optic  layer,  is  a 
vesicular  stratum  (Fig.  166,  6),  which  consists  of  a  finely-granular  matrix, 
wherein  are  imbedded  nerve-cells  exactly  resembling  those  of  the  Encephalon, 
and  having,  like  them,  a  variable  number  of  processes,  some  of  which  appear  to 
become  continuous  with  the  fibres  about  to  be  described.  It  is  to  these  fibrous 
and  vesicular  layers  of  the  Retina,  which  together  make-up  the  analogue  of  the 
cortical  substance  of  the  Cerebrum,  that  the  principal  supply  of  blood  is  distrib- 
uted, by  the  minute  capillary  net-work  (168)  which  is  spread-out  through  their 
substance. — The  principal  part  of  the  thickness  of  the  Retina,  however,  is  made- 
up  of  a  series  of  layers  whose  structure  has  until  lately  been  completely  misunder- 
stood ;  and  though  their  real  character  cannot  be  regarded  as  yet  fully  elucidated, 
yet  a  great  step  has  been  made  in  advance  by  the  researches  of  H.  Miiller  and 
Kolliker.1  These  layers  as  seen  in  a  vertical  section  (Fig.  166),.  succeed  each 


FIG.  166. 


FIG.  167. 


( 


Vertical  Section  of  Retina  of  the 
Human  Eye  : — 1,  bacillar  layer ;  2, 
outer  layer  granular;  3,  intermediate, 
fibrous  layer;  4,  inner  granular 
layer ;  5,  finely  granular  grey  layer; 
6,  layer  of  nerve-cells;  7,  layer  of 
fibres  of  optic  nerve ;  8,  limitary 
membrane. 


Elements  of  Human  Retina:— I,  large  fibre  of  optic 
nerve ;  2  very  fine  fibre  of  the  same ;  3,  rod  with  a  gran- 
ule /  attached ;  4,  a  similar  rod  with  a  fine  fibrous  pro- 
longation, connecting  it  with  the  granule ;  5,  portions 
of  rods  altered  by  the  action  of  water ;  6,  7,  two  cones 
b  b,  with  their  nuclei  c  c,  their  bacillar  portions  d  d,  and 
their  fine  fibrous  prolongations  e  e  ;  8,  radiating  fibre 
e  e,  with  granule  of  outer  layer  g,  and  subdividing  in 
the  bacillar  layer,  as  well  as  in  the  optic  layer  h  ;  9,  con- 
nection of  rods  a,  with  granules  of  inner  layer  /,  gran- 
ule of  outer  layer  g,  and  expansion  of  the  fibre  pro- 
ceeding from  the  latter  in  the  optic  layer  at  h;  10,  simi- 
lar connection  of  cone  b,  c,  with  granule  g,  and  with 
nerve-cell  I,  which  has  another  fibrous  prolongation  m. 

See  the  memoir  of  the  former,  '  Zur  Histologie  der  Netzhaut,'  in  "  Kolliker  and 
Zeitschrift,"  1851 ;  and  the  "  Mikroskopische  Anatomic,"  band  ii.  §  274,  and  the 
"Manual  of  Human  Histology,"  (Sydenham  Society's  Ed.),  vol.  ii.  pp.  368-382,  of  the 
latter.  See  also  Mr.  Bowman's  "  Lectures  on  the  Parts  concerned  in  the  Operation 
on  the  Eye,"  p.  81,  and  Todd  and  Bowman's  "Physiological  Anatomy." 


SENSE    OF    VISION:  —  STRUCTURE    OF    RETINA.        673 

other  from  within  outwards  as  follows  : — In  contact  with  the  vesicular  layer  (6) 
is  a  layer  of  finely-granular  matter  of  a  greyish  hue,  in  which  an  indistinct, 
radiating  fibrous  appearance  is  seen ;  next  is  a  layer  of  definite  granules  (4), 
which  seem  like  minute  cells  closely  investing  nuclei ;  outside  this  is  another 
layer  (3),  in  which  the  appearance  of  radiating  fibres  is  more  distinct ;  this, 
again,  is  succeeded  by  another  granular  layer  (2)  resembling  the  preceding ;  and  out- 
side all  these  is  the  layer  (i)  of  '  cones'  and  l  rod-like'  bodies,  which  has  long  been 
known  as  l  Jacob's  membrane/  This  last  has  been  supposed  to  be  entirely  discon- 
nected, both  structurally  and  functionally  from  the  proper  nervous  apparatus  of 
the  Retina ;  but  recent  investigations  have  made  it  probable  that  it  really  forms 
part  of  it.  For  the  '  rods'  or  '  staff-like'  bodies  (Fig.  167,  a  a),  may  be  traced  into 
continuity  with  the  granules  (/,  /)  of  the  outer  granular  layer,  sometimes  imme- 
diately by  the  intervention  of  a  fine  fibrous  prolongation ;  and  from  the  granules  of 
the  outer  layer,  fine  fibres  (e,  e)  may  be  traced  towards  those  of  the  inner  layer  (*?,  <?). 
So,  again,  the  '  cones '  (b,  I),  whose  outer  extremities  (W,  d]  are  often  seen  on  the 
external  surface  as  '  rods,'  may  be  traced  into  continuity  with  the  granular  layers 
(/>  9i)  by  the  intermediation  of  fine  fibres  (e,  e).  And  from  the  outer  granular 
layer,  similar  very  delicate  fibres  are  found  to  pass  towards  the  vesicular  layer, 
where  some  of  them  appear  to  come  into  absolute  continuity  with  the  radiating 
prolongations  of  the  nerve-cells  (10,  0>  whilst  others  pass  through  the  vesicular 
layer,  and  expand  into  trumpet-shaped  terminations  (9,  A),  in  the  stratum  of 
optic  fibres.  The  effects  of  reagents,  moreover,  on  these  elements,  are.  such  as 
to  increase  this  probability.  It  is  to  be  remarked  especially  of  the  rod-like 
bodies,  that  they  are  very  speedily  and  remarkably  altered  by  the  contact  of 
water,  which  causes  them  to  undergo  contortions  and  irregular  bulgings  and  con- 
tractions (5). — Although  the  general  direction  of  the  fibrous  elements  of  the 
Retina  itself  (as  distinguished  from  those  of  the  expansion  of  the  Optic  Nerve) 
is  radial  as  regards  the  globe  of  the  eye,  or  vertical  as  regards  any  part  of  the 
surface  of  the  membrane,  yet  there  are  situations  in  which  the  rod-like  bodies  are 
directed  so  obliquely,  as  to  present  quite  an  imbricated  arrangement  upon  the 
external  surface  (Fig.  169). 

FIG.  168.  FIG.  169. 


Distribution  of  Capillaries  in  the  Vascular         Part  of  external  surface  of  Retina  of  Frog 

layer  of  the  Itetina.  showing  the   imbricated  arrangement  of  the 

extremites  of  the  rods  of  'Jacob's  Membrane. 

755.  There  are  two  spots  in  the  Retina,  in  which  the  arrangement  of  the 
foregoing  components  is  essentially  different ;  and  from  these  differences,  im- 
portant physiological  conclusions  may  be  drawn.  One  of  these  is  the  slight  emi- 
nence at  which  the  Optic  nerve  enters,  which  is  a  little  below  and  internal-to  the 
posterior  extremity  of  the  axis  of  the  eye ;  here  all  the  other  elements  than  the 
nerve-fibres  are  entirely  wanting.  The  other  is  the  'yellow  spot  of  Soemmerins:,' 
which  is  situated  in  the  exact  centre  of  the  retina ;  here  the  stratum  of  optic 
fibres  is  wanting,  the  nerve-cells  being  in  immediate  contact  with  the  limitary 
43 


674        OF   THE   ORGANS   OF  THE   SENSES,   AND   THEIR   FUNCTIONS. 

membrane;  the  granular  layer  is  deficient  in  the  centre,  so  that  the  pigment  of 
the  choroid  is  visible  through  it ',  but  the  bacillar  layer  is  everywhere  continu* 
ous,  the  ordinary  '  rods/  however,  having  their  places  entirely  occupied  by  the 
1  cones/  whose  extremities  abut  upon  the  external  surface,  instead  of  being  re- 
moved from  it  as  elsewhere. — Now  it  is  not  a  little  remarkable,  that  the  point  of  the 
entrance  of  the  Optic  nerve  should  be  deficient  in  the  power  of  receiving  distinct 
visual  impressions  (§  772) ;  whilst  the  <  yellow-spot '  is  the  most  sensitive  portion 
of  the  entire  Retina.  And  hence  it  seems  unequivocally  to  follow,  that  these 
impressions  cannot  act  primarily  upon  the  nerve-fibres; — a  conclusion  which  har- 
monizes with  the  fact,  that  the  fibres  of  the  optic  nerves  are  superimposed  upon 
each  other  in  the  stratum  which  they  form,  in  such  numbers  that  it  is  not  con- 
ceivable that  they  should  be  the  primary  recipients  of  luminous  impressions, 
since  their  transparency  must  allow  rays  of  light  to  penetrate  from  one  portion 
of  the  layer  to  another.  The  bacillary  layer  was  formerly  regarded  as  a  reflect- 
ing apparatus,  having  for  its  purpose  to  stop  the  further  passage  of  light,  and  to 
intensify  its  influence  on  the  true  retina ;  but  since  its  connection  with  the  proper 
nervous  elements  of  the  retina  has  been  established,  there  seems  much  ground 
for  believing  (with  Prof.  Kb'lliker)  that  its  rods  and  cones  are  the  primary  reci- 
pients of  luminous  impressions,  and  that  they  communicate  their  condition  to  the 
fibres  of  the  optic  nerve,  by  means  of  their  own  delicate  fibrous  prolongations, 
which  seem  to  come  into  more  or  less  direct  connection  with  its  ultimate  ramifi- 
cations., This  supposition  derives  confirmation  from  the  remarkable  fact,  that  the 
diameter  of  the  rods  bears  a  very  close  correspondence  with  the  dimensions  of  the 
retinal  images  of  the  smallest  objects  of  which  we  can  take  cognizance  (§  756) 
And  it  harmonizes  well,  also,  with  the  idea  recently  put-forth,  that  the  obliquity 
of  the  rods  is  such  as  to  make  them  all  point  towards  'the  centre  of  direction'  of 
the  visual  rays  (§  759) ;  and  that  it  is  through  this  instrumentality,  that  we  are 
guided  in  our  appreciation  of  the  relative  directions  of  different  objects,  as  Articu- 
lated animals  probably  are  by  the  impressions  made  on  the  individual  ocelli  of 
their  coa  pound  eyes  (PRINC.  OF  COMP.  PHYS.,  §  718,  Am.  Ed.),  since  the  object 
whose  rays  pass-down  any  one  of  these,  must  always  be  in  the  direction  of  its  axis. 

756.  The  limits  of  Human  Vision,  as  regards  the  minuteness  of  the  objects 
of  which  it  can  take  cognizance,  have  been  investigated  by  Prof.  Ehrenberg, 
with  the  view  of  calculating  the  ultimate  power  of  the  Microscope.2  In  opposi- 
tion to  the  generally-received  opinion,  Ehrenberg  arrived  at  the  conclusion  that, 
in  regard  to  the  extreme  limits  of  vision,  there  is  little  difference  amongst  per- 
sons of  ordinarily-good  sight,  whatever  may  be  the  focal  distance  of  their  eyes. 
The  smallest  square  magnitude  usually  visible  to  the  naked  eye,  either  of  white 
particles  on  a  black  ground,  or  of  black  upon  a  white  or  light-coloured  ground,  is 
about  the  l-405th  of  an  inch.  It  is  possible,  by  the  greatest  condensation  of 
light,  and  excitement  of  the  attention,  to  recognize  magnitudes  between  the 
l-405th  and  l-540th  of  an  inch ;  but  without  sharpness  or  certainty.  Bodies 
which  are  smaller  than  these,  cannot  be  discerned  with  the  naked  eye  when  sin- 
gle ;  but  may  be  seen  when  placed  in  a  row.  Particles  which  powerfully  reflect 
light,  however,  may  be  distinctly  seen,  when  not  half  the  size  of  the  least  of  the 
foregoing;  thus,  gold-dust3  of  the  fineness  of  l-1125th  of  an  inch,  may  be  dis- 
cerned with  the  naked  eye  in  common  daylight.  The  delicacy  of  vision  is  far 
greater  for  lines  than  for  mere  points ;  since  opaque  threads  of  l-4900th  of  an 
inch  in  diameter  (about  half  the  diameter  of  the  Silk-worm's  fibre)  may  be  dis- 
cerned with  the  naked  eye,  when  held  towards  the  light. — The  degree  in  which 
the  attention  is  directed  to  them,  has  a  great  influence  on  the  readiness  with 
which  very  minute  objects  can  be  perceived ;  and  Ehrenberg  remarks  that  there 

1  See  the  very  ingenious  "Essai  sur  les  Phosphenes,"  by  Dr.  Serre,  Paris,  1853. 

J ««  Taylor's  Scientific  Memoirs,"  vol.  i.  p.  676. 

*  Ehrenberg  mentions  that  he  obtained  the  finest  particles  of  gold,  by  scraping  gilt 
orass :  by  filing  pure  gold,  he  always  obtained  much  coarser  particles. 


SENSE    OF   VISION  I — STRUCTURE   AND   ACTIONS    OF   IRIS.  675 

is  a  much  greater  difference  amongst  individuals  in  this  respect,  than  there  is  in 
regard  to  the  absolute  limits  of  vision.  Many  persons  can  distinctly  see  such 
objects,  when  their  situation  is  exactly  pointed-out  to  them,  who  cannot  other- 
wise distinguish  them  ;  and  the  same  is  the  case  with  persons  of  acuter  percep- 
tion, with  respect  to  objects  at  distances  greater  than  those  at  which  they  can  see 
most  clearly.  "I  myself,"  says  Ehrenberg,  "cannot  see  l-2700th  of  an  inch,' 
black  or  white,  at  twelve  inches'  distance ;  but  having  found  it  at  from  four  or 
five  inches'  distance,  I  can  remove  it  to  twelve  inches,  and  still  see  the  object 
plainly."  Similar  phenomena  are  well  known  in  regard  to  a  balloon  or  a  faint 
star  in  a  clear  sky,  or  a  ship  in  the  horizon  :  we  easily  see  them  after  they  have 
been  pointed-out  to  us;  but  the  faculty  of  readily  descrying  objects  depends  on 
the  habit  of  using  the  eyes  in  search  of  them,  and  of  attending  to  the  sensory 
impressions  thus  received  (§  775). 

757.  The  amount  of  light  admitted  to  the  Eye  is  regulated  by  the  contraction 
and  dilatation  of  the  Pupil,  the  smallest  diameter  of  which  is  about  l-20th,  and 
its  largest  about  l-3rd  of  an  inch. 

The  muscular  structure  of  the  Hu-  FIG.  170. 

man  Iris  is  entirely  of  the  non-stri- 
ated kind,  being  composed  of  the 
elongated  fibre-cells  with  staff-shaped 
nuclei  which  are  characteristic  of  that 
variety.  Part  of  these  are  so  dis- 
posed as  to  form  a  circular  sphincter 
(Fig.  170,  a),  which  can  be  readily 
seen  in  the  iris  of  the  white  rabbit 
or  in  the  blue  iris  of  man  from  which 
the  uvea  has  been  removed,  immedi- 
ately surrounding  the  pupillary  mar- 
gin to  the  breadth  of  about  one  third 
of  a  line.  The  fibres  of  this  sphinc- 
ter are  not  absolutely  parallel,  espe- 
cially at  the  outer  margin,  where 
they  seem  to  become  continuous  with 
those  of  the  radiating  fasciculi  (&,£>), 
which  may  be  traced  from  this  sphinc- 
ter (though  usually  with  difficulty)  to  ***»?*  structure  of  the  Iris  of  a  White  Rabbit : 
.  J  «  , ,  ••  *'  —a,  sphincter  of  the  pupil :  6,  6,  radiating  fasciculi 

the  outer  margin  of  the  ins    some-  of  dilator  muscle.  Cf  c>  connective  tissue  wi<h  its 
times  anastomosing  with  each  other  corpuscles, 
in  their  course.1     The  contraction  of 

the  annular  fibres,  whereby  the  diameter  of  the  pupil  is  diminished,  is  effected, 
as  already  explained  (§  512),  through  the  instrumentality  of  the  Third  pair  of 
nerves }  the  contraction  of  the  radiating  fibres,  on  the  other  hand,  whereby  the 
pupil  is  dilated,  is  under  the  government  of  the  cervical  portion  of  the  Sympathetic, 
being  called-forth  (as  MM.  Budge  and  Waller  have  shown2)  by  irritation  of  the 
trunk  of  the  Sympathetic  in  the  neck  by  the  magneto-electric  apparatus,  whilst  a 
section  of  this  nerve  produces  a  permanent  contraction  of  the  pupil,  the  action  of 
the  Third  pair  being  then  no  longer  antagonized.  It  appears  from  other  experi- 
ments, that  the  fibres  through  which  this  movement  is  effected,  pass  through  the 
Grasserian  ganglion,  and  are  distributed  to  the  eye  by  the  ophthalmic  branch  of 
the  Fifth  pair  (§  492).  The  contraction  of  the  Pupil  answers  the  purpose,  as  we 
have  seen,  not  merely  of  excluding  superfluous  light  from  the  eye,  but  also  of 
cutting-off  the  most  divergent  rays,  when  the  object  is  brought  near  the  refracting 
surface  (§  752). 

1  See  Prof.  Kolliker's  "  Mikroskopische  Anatomic,"  band  ii.  \  272 ;  and  Jos.  J.  Lister's 
'Observations  on  the  Contractile  Tissue  of  the  Iris,' in  "Quart.  Journ.  of  Microscop. 
Science,"  vol.  i.  p.  8. 

a  "  Gazette  Me'dicale,"  1851,  Nos.  41,  44. 


676         OF  THE   ORGANS   OF  THE   SENSES,   AND   THEIR   FUNCTIONS. 

758.  The  sense  of  Vision  depends,  in  the  first  place,  on  the  excitement  of 
our  sensational  consciousness  by  the  ocular  picture  impressed  upon  the  retina, 
which  represents  the  outlines,  lights  and  shades,  colours,  and  relative  positions, 
of  the  objects  before  us ;  and  all  the  ideas  respecting  the  real  forms,  distances, 
&c.,  of  bodies,  which  we  found  upon  these  data,  are  derived  through  the  percep- 
tions, either  instinctively  or  experientially  suggested  by  sensations.  Many  of 
these  ideas  are  derived  through  the  combination,  in  our  minds,  of  the  Visual 
perceptions,  with  those  derived  from  the  sense  of  Touch.  Thus,  to  take  a  most 
simple  illustration,  the  idea  of  smoothness  is  one  essentially  tactile;  and  yet  it 
constantly  occurs  to  us,  on  looking  at  a  surface  which  reflects  light  in  a  particular 
manner.  But,  if  it  were  not  for  the  association  which  experience  leads  us  to 
form,  of  the  connection  between  polish  as  seen  by  the  eye,  and  smoothness  as  felt 
by  the  touch,  we  should  not  be  able  to  determine,  as  we  now  can  do,  the  exist- 
ence of  both  these  qualities,  from  an  impression  communicated  to  us  through 
either  sense  singly. — The  general  fact  that,  in  Man,  the  greater  part  of  those 
notions  of  the  external  world,  by  which  his  actions  in  the  adult  state  are  guided, 
are  acquired  by  the  gradual  association  of  the  two  sets  of  perceptions  derived 
through  the  Sight  and  through  the  Touch,  is  substantiated  by  amply-sufficient 
evidence ;  this  being  chiefly  derived  from  observations  made  upon  persons  born 
blind,  to  whom  sight  has  been  communicated  by  an  operation,  at  a  period  of  life 
which  enabled  them  to  give  an  accurate  description  of  their  sensations.  The 
case  recorded  by  Cheselden  is  one  of  the  most  interesting  of  these.  The  youth 
(about  twelve  years  of  age),  for  some  time  after  tolerably-distinct  vision  had  been 
obtained,  saw  everything  flat  as  in  a  picture,  simply  receiving  the  consciousness 
of  the  impression  made  upon  his  retina;  and  it  was  some  time  before  he  acquired 
the  power  of  judging,  by  his  sight,  of  the  real  forms  and  distances  of  the  ob- 
jects around  him.  An  amusing  anecdote,  recorded  of  him,  shows  the  complete 
want  which  there  is  in  Man,  of  any  natural  or  intuitive  connection  between  the 
ideas  formed  through  visual  and  through  tactile  sensations.  He  was  well  ac- 
quainted with  a  Dog  and  a  Cat  by  feeling,  but  could  not  remember  their  respec- 
tive characters  when  he  saw  them ;  and  one  day,  when  thus  puzzled,  he  took-up 
the  Cat  in  his  arms,  and  felt  her  attentively,  so  as  to  associate  the  two  sets  of 
ideas,  and  then,  setting  her  down,  said  "  So  puss,  I  shall  know  you  another 
time." — A  similar  instance  has  come  under  the  Author's  own  knowledge;  but 
the  subject  of  it  was  scarcely  old  enough  to  present  phenomena  so  striking. 
One  curious  circumstance  was  remarked  of  him,  which  fully  confirms  (if  confir- 
mation were  wanting)  the  view  here  given.  For  some  time  after  his  sight  was 
tolerably  clear,  the  lad  preferred  finding  his  way  through  his  father's  house  (to 
which  he  had  been  quite  accustomed  when  blind)  by  touch  rather  than  by  sight, 
the  use  of  the  latter  sense  appearing  to  perplex  instead  of  assisting  him ;  but, 
when  learning  a  new  locality,  he  employed  his  sight,  and  evidently  perceived  the 
increase  of  facility  which  he  derived  from  it.1 — The  actions  performed  by  many 
new-born  animals  (§  604)  do  not  constitute  any  valid  objection  to  the  view  that 
such  visual  perceptions  are  for  the  most  part  acquired  by  Man ;  for  all  that  is 
indicated  by  them  is,  that  certain  sensations  give-rise  to  movements  adapted  to 
supply  the  wants  to  which  they  relate ;  and  they  do  not  afford  any  proof  that 
definite  notions,  such  as  we  entertain,  of  the  forms  and  properties  of  external 
objects,  are  possessed  by  the  animals  which  exhibit  them. — We  shall  now  ex- 
amine, a  little  more  in  detail,  into  the  means  by  which  we  gain  such  notions,  and 
the  data  on  which  they  are  founded. 

759.  The  first  point  to  be  determined,  is  one  which  has  been  a  fruitful  source 
of  discussion, — the  cause  of  erect  vision,  the  picture  upon  the  retina  being  in- 

1  The  question  has  been  proposed,  whether  a  person  born  blind,  who  was  able  by  the 
sense  of  Touch  to  distinguish  a  cube  from  a  sphere,  would,  on  suddenly  obtaining  his 
Bight,  be  able  to  distinguish  them  by  the  latter  sense.  This  question  was  answered  by 
Locke  in  the  negative ;  and,  as  appears  from  the  facts  above  stated,  with  justice. 


SENSE    OF   VISION: — PERCEPTION   OF   DIRECTION.  677 

verto.d ;  and  with  this  is  connected  the  general  question  of  the  origin  of  our 
Sense  of  Direction. — The  difficulty  which  has  been  raised  in  regard  to  the  former 
subject,  is  rather  apparent  than  real  ;  being  founded  on  an  erroneous  notion  of 
the  nature  of  the  Visual  sense.  For  it  seems  to  have  been  supposed  that  we 
look  at  the  retinal  picture  with  the  f  mind's  eye/  just  as  we  look  at  the  picture 
formed  by  a  Camera  with  the  bodily  eye ;  and  that  our  consciousness  must  be 
therefore  impressed  by  its  discordance  with  the  information  which  we  receive 
through  our  sense  of  Touch.  Some  philosophers,  indeed,  have  actually  gone  so 
far  as  to  assert,  that  the  Infant  must  at  first  see  everything  inverted,  and  that 
the  erectness  of  visual  objects  is  only  learned  by  the  corrective  experience  gained 
by  touching  and  handling  them.  But  such  is  clearly  not  the  case  ;  for  the  visual 
perception  is  obviously  not  a  mere  transfer  of  the  sensorial  impression,  but  is  a 
mental  state  excited  by  it,  and  therefore  related  to  it  as  an  effect  to  its  cause; 
and  we  know  no  reason  why  it  should  be  less  natural  for  the  retinal  picture  to 
suggest  to  the  mind  the  notion  of  erect  position,  than  for  it  to  have  the  contrary 
effect.  Moreover,  it  will  appear  from  recent  investigations  to  be  hereafter  de- 
tailed (§  773),  that  there  is  in  the  eye  a  common  '  centre  of  direction/  through 
which  all  lines  must  pass,  that  are  drawn  from  any  points  of  an  external  object 
to  the  corresponding  points  of  its  retinal  image ;'  and  that  we  intuitively  refer 
the  cause  of  the  excitation  of  any  spot  of  the  retina  by  a  luminous  impression, 
to  an  objective  source  in  the  Mine  of  direction'  which  passes  from  that  spot 
through  the  centre  of  direction ;  so  that,  in  virtue  of  this  *  law  of  visible  direc- 
tion/ as  all  the  lines  of  direction  cross  each  other  both  vertically  and  laterally, 
the  formation  of  an  inverted  image  upon  our  retina  suggests  to  our  minds  the 
representation  of  the  object  in  its  erect  position,  and  the  same  reversal  takes- 
place  also  in  regard  to  its  two  sides,  which  are  transposed  in  the  retinal  picture. 
A  peculiar  arrangement  of  the  receptive  apparatus,  which  seems  to  be  subser- 
vient to  this  mental  appreciation  of  direction,  has  been  already  noticed  (§  755). 
760.  The  cause  of  Single  Vision  with  the  two  Eyes  has,  in  like  manner,  been 
the  subject  of  much  discussion  ;  and  here,  too,  the  difficulty  is  rather  apparent 
than  real,  having  for  its  foundation  the  idea  that  the  mind  looks  at  the  two  re- 
tinal pictures  as  at  two  separate  objects,  instead  of  being  impressed  by  a  certain 
state  of  the  Sensorium,  which  may  be  excited  through  the  instrumentality  of 
either  eye,  or  through  that  of  both  in  combination.  Some  have  even  asserted, 
under  the  influence  of  this  idea,  that  we  do  not  really  employ  both  eyes  simul- 
taneously, but  that  the  mind  is  affected  by  the  image  communicated  by  one  only; 
which  might  seem  to  be  confirmed  by  the  fact  heretofore  mentioned  (§  592), 
respecting  the  alternate  use  of  the  two  eyes,  when  they  are  looking  through  two 
differently-coloured  media.  But  of  this  assertion  a  complete  disproof  is  afforded 
by  the  knowledge  we  now  possess  (§  761),  that  our  appreciation  of  the  solid 
forms  of  bodies  depends  on  the  combination,  by  the  Mind,  of  the  images  simul- 
taneously suggested  by  the  two  pictures ;  and  that  our  knowledge  of  distances  i8 
in  great  part  obtained  in  like  manner. — Attempts  have  been  made  to  explain  the 
phenomena  of  Single  Vision  by  the  peculiar  decussation  of  the  Optic  Nerves 
formerly  described  (§  523);  it  being  supposed  that  only  one  Optic  Ganglion  would 
be  affected  by  an  impression  made  upon  both  Retinae.  This  explanation,  how- 
ever, even  supposing  the  fact  to  be  as  stated,  would  be  far  from  affording  the 

1  With  regard  to  the  precise  situation  of  this  '  centre  of  direction,'  there  is  a  want  of 
accordance  among  those  who  have  attempted  to  determine  it ;  some  having  placed  it  in  the 
centre  of  the  pupil,  others  in  the  centre  of  the  crystalline  lens,  others  at  various  distances 
between  this  and  the  centre  of  the  globe,  and  others  (among  them  Sir  D.  Brewster)  in  the 
centre  of  the  globe.  This  last  notion,  and  the  'law  of  visible  direction'  founded  upon 
it, — which  affirms  that  every  object  is  seen  in  the  direction  of  the  perpendicular  (or  radius) 
to  every  point  of  the  retina  which  is  impressed, — is  so  manifestly  wrong,  that  it  is  difficult 
to  conceive  how  it  could  ever  have  been  entertained  by  men  of  science.  The  experimental 
investigations  of  Dr.  Serre  ($  773)  lead  him  to  regard  the  centre  of  the  crystalline  as  the 
'centre  of  direction.' 


678      OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

eolation  of  the  problem ;  and  it  would  be  entirely  inapplicable  to  that  very  im- 
portant series  of  phenomena  to  be  next  described,  which  show  how  large  an 
amount  of  information  we  derive,  not  from  the  repetition,  but  from  the  difference, 
of  the  sensory  impressions  made  by  the  same  object  upon  our  two  retinae;  and 
which  indicate  that  here,  as  in  the  case  of  erect  vision,  the  mental  interpretation 
of  the  sensory  impressions  is  a  process  altogether  removed  from  the  simple  affec- 
tion of  the  consciousness  by  those  impressions,  and  is  not  to  be  accounted-for  by 
any  structural  arrangements  of  the  Sensorial  apparatus.  One  condition  of  Single 
Vision,  however,  seems  to  be  this,  that  the  two  images  of  the  object  should  be 
formed  on  parts  of  the  two  retinae  which  are  accustomed  to  act  in  concert ;  and 
habit  appears  to  be  the  chief  means  by  which  this  conformity  is  produced  (§  800). 
There  can  be  no  doubt,  however,  that  double  images  are  continually  being  con- 
veyed to  the  Sensorium ;  but  that,  from  their  want  of  force  and  distinctness, 
and  from  the  attention  being  fixed  on  something  else,  we  do  not  take  cognizance 
of  them.  This  may  be  shown  by  a  very  simple  experiment.  If  two  fingers  be 
held-up  before  the  eyes,  one  in  front  of  the  other,  and  vision  be  directed  to  the 
more  distant,  so  that  it  is  seen  singly,  the  nearer  will  appear  double ;  while,  if  the 
nearer  one  be  regarded  more  particularly,  so  as  to  appear  single,  the  more  distant 
will  be  seen  double.  A  little  consideration  will  show,  therefore,  that  our  minds 
must  be  thus  continually  affected  with  sensations,  which  cannot  be  united  into 
the  idea  of  a  single  image ;  since,  whenever  we  direct  the  axes  of  our  eyes  to- 
wards any  object,  everything  else  will  be  represented  to  us  as  double ;  but  we 
do  not  ordinarily  perceive  this,  from  our  minds  being  fixed  upon  a  clear  and 
distinct  image,  and  disregarding,  therefore,  the  vague  undefined  images  formed 
by  objects  not  in  the  visual  focus.  Of  this  it  is  very  easy  to  satisfy  one's-self. — 
This  experiment,  moreover,  makes  it  evident  that  double  vision  cannot  result 
from  want  of  symmetry  in  the  position  of  the  images  upon  the  retina,  to  which 
some  have  attributed  it;  for  it  answers  equally  well,  if  the  line  of  the  two  fingers  be 
precisely  in  front  of  the  nose,  so  that  the  inclination  of  both  eyes  towards  either 
object  is  equal;  the  position  of  the  images  of  the  second  object  must  then  be  at 
the  same  distance  on  either  side  from  the  central  line  of  the  retina,  and  yet  they 
are  represented  to  the  mind  as  double.  Hence,  too,  it  seems  clear  that  single- 
ness of  vision  in  an  object  that  is  looked-at,  is  also  dependent  in  part  upon  the 
convergence  of  the  optic  axes  in  that  object  (§752);  and  that  this  is  the  case 
appears  further  from  a  curious  experiment  devised  by  Prof.  Wheatstone,  in  which 
two  similar  objects  are  made  to  seem  as  one,  when  they  are  placed  in  the  line 
of  convergence.  This  is  accomplished  by  looking  through  two  tubes,  placed 
before  the  right  and  left  eyes  respectively,  at  two  similar  objects  of  any  descrip- 
tion, placed  near  the  farther  extremities  of  the  tubes ;  if,  now,  these  objects  be 
slightly  approximated,  so  that  the  axes  of  the  tubes  (still  directed  towards  them) 
meet  in  a  point  beyond,  the  mind  is  impressed  with  the  image  of  only  a  single 
object,  and  this  appears  to  be  removed-back  to  the  point  of  convergence. 

761.  On  the  mode  in  which  our  notion  of  the  solid  forms  and  relative  projec- 
tion of  objects  is  required,  great  light  has  been  thrown  by  the  interesting  experi- 
ments of  Prof.  Wheatstone.1  It  seems  perfectly  evident,  both  from  reason  and 
experience,  that  the  flat  picture  upon  the  retina,  which  is  the  immediate  source 
of  our  sensation,  could  not  itself  convey  to  our  minds  any  notion,  but  that  of  a 
corresponding  plane  surface.  In  fact,  any  notion  of  solidity,  which  might  be 
formed  by  a  person  who  had  never  had  the  use  of  more  than  one  eye,  would 
entirely  depend  upon  the  combination  of  his  visual  and  tactile  sensations.  This 
view  is  fully  confirmed  by  the  case  already  referred-to  (§  758),  as  recorded  by 
Cheselden.  The  first  visual  idea  entertained  by  the  youth  was,  that  the  objects 
around  him  formed  a  flat  surface,  which  touched  his  eyes,  as  they  had  previously 
been  in  contact  with  his  hands ;  and  after  this  notion  had  been  corrected,  through 
ihe  education  of  his  sight  by  his  touch,  he  fell  into  the  converse  error  of  sup- 

1  "Philosophical  Transactions,"  1838  and  1852. 


SENSE   OF   VISION: — PERCEPTION   OP   SOLIDITY.  679 

posing  that  a  picture,  which  was  shown  to  him,  was  the  object  itself  represented 
in  relief  on  a  small  scale. — But  where  both  eyes  are  employed,  it  has  been  ascer- 
tained by  Prof.  Wheatstone,  that  they  concur  in  exciting  the  perception  of  solidity 
or  projection,  which  arises  from  the  mental  combination  of  the  two  dissimilar 
pictures  formed  upon  the  two  retinae.  It  is  easily  shown,  that  any  near  object 
is  seen  in  two  different  modes  by  the  two  eyes.  Thus  let  the  reader  hold-up  a 
thin  book,  in  such  a  manner  that  its  back  shall  be  exactly  in  front  of  his  nose, 
and  at  a  moderate  distance  from  it;  he  will  observe,  by  closing  first  one  eye  and 
then  the  other,  that  his  perspective  view  of  it  (or  the  manner  in  which  he  wouul 
represent  it  on  a  plane  surface)  is  very  different,  according  to  the  eye  with  which 
he  sees  it.  With  the  right  eye  he  will  see  its  right  side,  very  much  fore- 
shortened ;  with  the  left,  he  will  gain  a  corresponding  view  of  the  left  side ;  and 
the  apparent  angles,  and  the  lengths  of  the  different  lines,  will  be  found  to  be 
very  different  in  the  two  views.  On  looking  at  either  of  these  views  singly,  no 
other  notion  of  solidity  can  be  acquired  from  it,  than  that  to  which  the  mind  is 
conducted,  by  the  association  of  such  a  view  with  the  touch  of  the  object  which 
it  represents.  But  it  is  capable  of  proof,  that  the  mental  association  of  the  dif- 
ferent pictures  upon  the  two  retinae,  does  of  itself  give  rise  to  the  idea  of  solidity. 
This  proof  is  afforded  by  Prof.  Wheatstone's  ingenious  instrument,  the  Stereo- 
scope first  described  by  him  in  1838. ' 

762.  The  Stereoscope  in  its  original  form  essentially  consists  of  two  plane 
mirrors,  inclined  with  their  backs  to  one  another  at  an  angle  of  90°.  If  two  per- 
spective drawings  of  any  solid  object,  as  seen  at  a  given  distance  with  the  two 

Fio.  171. 


eyes  respectively,  such  as  those  at  A  and  B,  Fig.  171,  be  so  placed  before  these 
mirrors,  one  before  each,  that  their  two  images  shall  be  made  to  fall  upon  the 

1  Var^us  modifications  of  this  instrument  have  been  subsequently  introduced ;  and  there 
is  one  which  has  recently  (1852)  come  into  very  extensive  use,  in  which  the  two  monocular 
pictures  placed  side  by  side,  as  in  Figs.  171,  172,  are  viewed  by  the  two  eyes  respectively 
through  two  halves  of  a  convex  lens.  The  great  advantage  of  this  instrument  is  its 
portability,  and  its  enlargement  of  the  pictures  by  the  magnifying  power  of  the  lenses; 
but  it  is  limited  to  pictures  of  small  size,  since  the  distance  between  corresponding  points 
of  the  two  pictures  must  not  exceed  the  distance  between  the  centres  of  the  two  eyes ;  and1 
it  is  incapable  of  many  adaptations  which  can  be  made  with  the  mirror-stereoscope. — As 
Sir  D.  Brewster  has  recently  put-forth  his  claim  as  an  original  discoverer,  in  regard  to  th* 
truths  of  binocular  vision  which  have  been  established  by  the  Stereoscope,  on  the  strength 
of  some  comparatively  trivial  improvements  in  the  construction  of  the  instrument,  th«> 


680         OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

corresponding  parts  of  the  two  retinae,  in  the  same  manner  as  the  two  images 
formed  by  the  solid  object  itself  would  have  done,  the  mind  will  perceive,  not  a 
single  representation  of  the  object,  nor  a  confused  blending  of  the  two,  but  a 
projecting  or  receding  surface,  the  exact  counterpart  of  that  from  which  the  draw- 
ings were  made.1  The  solid  form  is  forcibly  impressed  on  the  mind,  even  when 
outlines  only  are  given,  especially  if  these  be  delineations  of  simple  geometrical 
figures,  easily  suggested  to  the  mind ;  and  it  may  be  readily  shown  that  the  very 
same  outlines  will  suggest  different  conceptions,  according  to  the  mode  in  which 
they  are  placed.  Thus  in  Fig.  172,  the  upper  pair  of  figures  A,  B,  when  com- 

FIG.  172. 


bined  in  the  Stereoscope,  excite  the  idea  of  a  projecting  truncated  pyramid,  nitl 
the  small  square  in  the  centre,  and  the  four  sides  sloping  equally  away  from,  it; 
whilst  the  lower  pair  of  figures,  c,  D,  which  are  the  same  as  the  upper,  but  trans- 
ferred to  the  opposite  sides,  no  less  vividly  bring  before  the  mind  the  visual  con- 
ception of  a  receding  pyramid,  still  with  the  small  square  in  the  centre,  and  the 
four  sides  sloping  equally  towards  it.  —  Prof.  Wheatstone  has  further  shown,  by 
means  of  the  Stereoscope,  that  similar  images,  differing  to  a  certain  extent  in 
magnitude,  when  presented  to  the  corresponding  parts  of  the  two  retinae,  give- 
rise  to  the  perception  of  a  single  object,  intermediate  in  size  between  the  two 
monocular  pictures.  Were  it  not  for  this,  objects  would  appear  single,  only  when 
at  an  equal  distance  from  both  eyes,  so  that  their  pictures  upon  the  retina  are  of 
the  same  size ;  which  will  only  happen,  when  they  are  directly  in  front  of  the 
median  line  of  the  face.  Again,  if  pictures  of  dissimilar  objects  be  simulta- 
neously presented  to  the  two  eyes,  the  consequence  will  be  similar  to  that  which 
is  experienced,  when  the  rays  come  to  the  eye  through  two  differently-coloured 
media ;  the  two  images  do  not  coalesce,  nor  do  they  appear  permanently  super- 
posed one  upon  the  other;  but  at  one  time  one  image  predominates  to  the  exclu- 
sion of  the  other,  and  then  the  other  is  seen  alone;  and  it  is  only  at  the  moment 
of  change,  that  the  two  seem  to  be  intermingled.  It  does  not  appear  to  be  in 

Author  feels  it  due  to  Prof.  Wheatstone  to  state  his  own  conviction,  founded  upon  a 
careful  examination  of  the  whole  history  of  the  invention,  that  the  entire  merit  of  the  idea, 
—  that  all  our  perception  of  solidity  derived  through  the  visual  sense  is  consequent  upon 
the  mental  combination  of  the  two  dissimilar  pictures  upon  the  two  retinae, — and  further, 
that  the  whole  merit  of  the  realization  of  that  idea  by  means  of  the  mirror-stereoscope, 
long  before  Sir  D.  Brewster's  attention  had  been  given  to  the  subject  at  all, — belongs  to 
Prof.  Wheatstone. 

1  The  most  striking  effect  is  produced  by  two  Photographic  pictures,  taken  at  the  same 
time  by  two  cameras,  so  placed  that  their  axes  shall  form  the  same  angle  with  each  other 
as  that  which  the  axes  of  the  two  eyes  would  form  when  looking  at  the  same  object.  This 
adaptation,  though  the  credit  has  been  assumed  by  others,  was  originally  devised  bvProf. 
V\  heatstoue. 


SENSE   OF   VISION:  —  ESTIMATION   OF   DISTANCE.         681 

the  power  of  the  Will,  Prof  Wheatstone  remarks,  to  determine  the  appearance 
of  either ;  but  if  one  picture  be  more  illuminated  than  the  other,  it  will  be  seen 
during  a  larger  portion  of  the  time.  If,  however,  the  differences  in  the  two  pic- 
tures be  such  that  the  Mind  can  reconcile  them,  an  intermediate  conception  is 
formed ;  thus  if  two  photographic  portraits  be  taken  at  the  proper  angle  for  the 
Stereoscope,  not  simultaneously  but  consecutively,  and  the  'sitter'  alter  his  ex- 
pression in  the  interval,  so  that  one  of  the  portraits  represents  him  with  a  smile, 
and  the  other  with  a  frown,  the  Stereoscopic  image  will  present  an  intermediate 
expression  of  placidity.  —  Many  other  curious  experiments  with  this  simple  in- 
strument are  related  by  Prof.  Wheatstone ;  and  they  all  go  to  confirm  the  gene- 
ral conclusion,  that  the  combination  of  the  dissimilar  images  furnished  by  the 
two  eyes  is  a  mental  act,  the  resultant  of  which,  in  the  case  of  all  objects  that 
are  near  enough  to  be  seen  in  different  perspective  with  the  two  eyes,  is  a  mental 
image  (referred  to  the  visual  sense)  possessing  the  attributes  of  solidity  and  pro- 
jection. In  regard  to  distant  objects,  however,  the  difference  in  the  images  formed 
by  the  two  eyes  is  so  slight,  that  it  cannot  aid  in  the  determination ;  and  hence  it  is, 
that  whilst  we  have  no  difficulty  in  distinguishing  a  picture,  however  well  painted, 
from  a  solid  object,  when  placed  near  our  eyes,  (since  the  idea  which  might  be 
suggested  by  the  image  formed  on  one  eye,  will  then  be  corrected  by  the  other),1 
we  are  very  liable  to  be  misled  by  a  delineation,  in  which  the  perspective,  light  and 
shade,  &c.,  are  faithfully  depicted,  if  we  are  placed  at  a  distance  from  it,  and  are 
prevented  from  perceiving  that  it  is  but  a  picture.2  In  this'  case,  however,  a 
slight  movement  of  the  head  is  sufficient  to  undeceive  us ;  since  by  this  move- 
ment a  great  change  would  be  occasioned  in  the  perspective  view  of  the  object, 
supposing  it  to  possess  an  uneven  surface;  whilst  it  scarcely  affects  the  image 
formed  by  a  picture.  In  the  same  manner,  a  person  who  only  possesses  one  eye, 
may  obtain,  by  a  slight  motion  of  his  head,  the  same  idea  of  the  form  of  a  body, 
which  another  would  acquire  by  the  simultaneous  use  of  his  two  eyes. 

763.  Our  appreciation  of  the  relative  Distances  of  near  objects,  stems  to  be 
derived  in  like  manner  from  the  mental  combination  of  the  perceptions  derived 
from  the  dissimilar  pictures  upon  the  two  retinae,  assisted  by  the  sensations 
derived  from  the  muscles  of  the  eyeballs,  which  are  put  in  action  to  bring  the 
optic  axes  into  the  requisite  convergence.  How  much  our  right  estimation  of  the 
relative  distances  of  objects  not  too  far  removed  from  the  eye,  depends  upon  the 
joint  use  of  both  eyes,  is  made  evident  by  the  fact,  that,  if  we  close  one  eye,  we 
rind  ourselves  unable  to  execute  with  certainty  many  actions  (such  as  threading  a 
needle,  or  snuffing  a  candle)  which  require  its  guidance.  In  proportion  as  the  object 
is  approximated  to  the  eyes,  slight  differences  of  distance  produce  marked  differ- 
ences in  the  degree  of  convergence,  and  these  are  readily  appreciated  so  as  to 
afford  the  means  of  very  nice  discrimination  :  whilst,  on  the  other  hand,  in  pro- 
portion as  they  are  removed  further  and  further,  do  the  optic  axes  approach 
parallelism,  and  the  power  of  appreciating  differences  of  distance  is  lost.  It  is 
the  usual  opinion  that  the  muscular  sensation  which  accompanies  the  inclination 
of  the  optic  axes,  immediately  suggests  the  notion  of  the  distance  of  an  object; 
and  that  our  appreciation  of  its  size  depends  upon  a  secondary  interpretation  of 
the  magnitude  of  its  picture  on  the  retina,  on  the  basis  of.  this  notion.  But  it 
would  appear  from  the  experiments  of  Prof.  Wheatstone,  that  the  reverse  is  the 

1  It  is  a  remarkable  illustration  of  this  principle,  that  a  photographic  representation  of 
a  landscape,  building,  &c.,  when  viewed  with  one  eye  at  a  moderate  distance,  frequently 
brings  the  real  scene  far  more  forcibly  before  the  mental  vision  than  when  it  is  looked  at 
with  both  eyes ;  since,  in  the  latter  case,  the  mind  cannot  avoid  perceiving  the  flatness  of 
its  surface ;  whilst,  in  the  former,  the  perspective,  and  the  distribution  of  the  lights  and 
shadows,  are  free  to  suggest  to  the  mind  the  relative  distances  and  projections  of  the 
several  parts. 

a  This  delusion  has  been  extremely  complete,  in  some  of  those  who  have  seen  the  pano- 
ramic view  of  London  in  the  Colosseum.  A  lively  and  interesting  account  of  it  is  given  in 
the  Journal  of  the  Parsee  Shipbuilders,  who  visited  England  some  years  ago. 


682        OF  THE   OKGANS   OF  THE   SENSES,   AND   THEIR   FUNCTIONS. 

case ;  the  sensation  of  convergence  assisting  in  the  first  instance  to  determine  the 
size,  and  the  appreciation  of  distance  being  a  secondary  judgment  based  on  this 
foundation  (§  766). — -The  power  of  estimating  distance  from  the  foregoing  data, 
however,  is  obviously,  in  Man,  not  an  intuitive  but  an  acquired  endowment ;  for 
it  is  evident  to  any  observer,  that  infants,  or  older  persons  who  have  but  recently 
acquired  sight,  form  very  imperfect  ideas  respecting  the  distance  of  objects ; 
their  attempts  to  grasp  bodies  which  attract  their  attention,  being  for  a  long  time 
unsuccessful,  so  that  they  only  gradually  learn  to  measure  distances  by  the  sight, 
through  the  medium  of  the  touch.  And  it  seems  to  follow  from  this,  that  even 
the  notion  of  '  projection,  which  we  seem  necessarily  to  form  when  looking  at  a 
solid  object  within  a  moderate  distance,  or  a  properly-adjusted  pair  of  Stereoscopic 
pictures,  is  not  derived  from  an  original  intuition,  but  is  the  result  of  the  associa- 
tion of  our  visual  with  our  tactile  experience,  very  early  in  life,  so  as  to  constitute 
a  '  secondary  intuition '  on  which  all  our  subsequent  appreciation  of  projection  is 


764.  In  regard  to  remote  objects,  our  judgment  of  Distance  is  chiefly  founded 
upon  their  apparent  size,  if  their  actual  size  be  known  to  us ;  but,  if  this  be  not 
the  case,  and  if  we  are  so  situated  that  we  cannot  judge  of  the  intervening  space, 
we  principally  form  our  estimate  from  that  effect  of  different  degrees  of  remote- 
ness upon  the  distinctness  of  their  colour  and  outline,  which  is  known  to  Artists 
as  '  aerial  perspective/     Hence  this  estimate  is  liable  to  be  greatly  affected  by 
varying  states  of  the  atmosphere,  as  is  particularly  known  to  every  one  who  has 
visited  warmer  climates ;  where  the  extreme  clearness  of  the  air  sometimes  brings 
into  apparently-near  proximity  a  hill  that  rises  some  miles  beyond  a  neighbouring 
ridge  (the  intervening  space  being  hidden,  so  as  not  to  afford  any  datum  for  the 
estimate  of  the  distance  of  the  remote  hill,  whilst  a  slight  haziness  carries  its 
apparent  distance  to  three  or  four  times  the  reality. 

765.  Our  estimate  of  the  Size  of  a  remote  object  is  partly  dependent  upon  the 
visual  angle  under  which  we  see  it,  and  partly  upon  our  estimate  of  its  distance.1 
The  '  visual  angle/  formed  by  imaginary  lines  drawn  from  the  eye  (Fig.  173,  A) 


!  "When  objects  are  so  remote  that  we  have  no  means  of  even  approximately  estimating 
their  distance,  we  have  no  measure  whatever  of  their  size.  Thus,  the  Sun  and  the  Moon 
are  of  nearly  the  same  apparent  size  to  us,  though  one  is  about  four  hundred  times  the 
distance  of  the  other ;  and  we  may  cover  either  disc  with  a  sixpence  held  near  the  eye,  so 
as  to  be  seen  under  the  same  visual  angle  ;  but  we  do  not  possess  the  least  power  of  esti- 
mating the  actual  sizes  of  these  objects,  save  by  a  calculation  based  on  a  knowledge  of 
their  relative  distances. 


SENSE    OF    VISION: — ESTIMATION    OF    SIZE.  683 

to  the  extreme  points  B,  c,  of  the  object,  is  the  measure  of  the  dimension  of  its 
image  upon  the  retina;  and  it  is  obvious  that,  if  two  objects,  B  c,  D  E,  the  former 
being  twice  the  length  of  the  latter,  be  placed  at  the  same  distance,  the  visaul 
angle  BAG  being  twice  as  great  as  the  angle  D  A  E,  the  image  of  B  C  upon  the 
retina  will  be  twice  as  long  as  that  of  D  E,  and  the  mind  will  estimate  their  rela- 
tive sizes  accordingly.  But  if  the  distance  of  the  object  D  E  from  the  eye  be 
diminished  to  one-half,  so  that  it  is  brought  into  the  position  p  G,  its  visual 
angle,  and  consequently  the  size  of  its  image  on  the  retina,  will  now  be  equal  to 
that  of  B  c;  and  the  estimate  we  form  of  the  relative  sizes  of  the  two,  will  en- 
tirely depend  upon  the  idea  we  entertain  of  their  relative  distances.  Hence  any 
circumstance  which  modifies  that  idea,  produces  a  corresponding  difference  in  our 
estimate  of  their  size;  so  that  the  apparent  size  of  an  object,  seen  under  the 
same  visual  angle,  may  be  estimated  as  larger  or  smaller  than  the  reality,  accord- 
ing as  we  suppose  it  to  be  more  or  less  distant  than  it  really  is.  Of  this  we  have 
a  familiar  instance  in  the  fact,  that  if  we  meet  a  child  whilst  we  are  walking 
across  a  common  in  a  fog  (the  flatness  of  the  ground  not  giving  as  much  power 
of  estimating  the  intervening  space),  it  appears  to  have  the  stature  of  a  man, 
and  a  man  seems  like  a  giant;  for  the  indistinctness  of  outline  causes  the  mind 
to  conceive  of  the  figures  as  at  a  greater  distance  than  they  really  are,  and  their 
apparent  dimensions  are  augmented  in  like  proportion.  For  if  the  object  F  G 
(Fig.  173)  be  mentally  carried-back  to  the  distance  of  D  E,  being  still  seen  under 
the  visual  angle  F  A  G  (or  B  A  c),  it  will  appear  to  possess  the  length  B  c  instead 
of  D  E.  On  the  other  hand,  if  the  object  B  c  were  to  be  mentally  brought  for- 
wards into  the  position  K  L,  its  apparent  size  being  still  determined  by  its  visual 
angle,  it  will  seem  to  be  reduced  to  the  length  F  G. 

766.  That  our  estimate  of  the  Size  of  near  objects,  however,  depends  upon  a 
more  direct  process,  seems  to  be  a  necessary  inference  from  the  following  very 
ingenious  experiments,  made  by  Prof.  Wheatstone  with  a  modification  of  his  Mir- 
ror-Stereoscope, devised  for  separately  testing  the  influence  of  the  two  conditions, 
— namely,  the  magnitude  of  the  retinal  picture,  and  the  degree  of  convergence 
of  the  optic  axes, — which  are  ordinarily  in  action  together.  When  an  object  is 
moved  nearer-to  or  farther-from  the  eye,  its  perceived  or  estimated  magnitude 
undergoes  no  change.  But  if  two  pictures,  placed  in  the  mirror-stereoscope,  be 
made  to  move  to  and  from  the  mirrors,  in  such  a  manner  as  to  vary  their  dis- 
tances from  these  (and  therefore  from  the  eyes),  without  altering  the  angle  of 
convergence,  their  perceived  magnitudes  are  augmented  and  reduced,  in  precise 
proportion  to  the  increased  and  diminished  sizes  of  the  retinal  pictures.  Con- 
versely, if  the  two  pictures  be  made  so  to  change  their  places  in  regard  to  the 
mirrors  (by  moving  in  a  horizontal  circle,  of  which  the  middle-point  between  the 
mirrors  is  the  centre),  that  the  angle  of  convergence  is  increased  or  diminished, 
as  it  would  be  if  the  object  were  brought  nearer  to  the  eyes  or  removed  farther 
from  them,  the  perceived  magnitude  of  the  pictures  is  altered  in  an  inverse  man- 
ner; being  reduced  when  the  angle  of  convergence  is  increased,  and  increased 
when  the  inclination  of  the  optic  axes  is  lessened  so  as  to  approach  parallelism. 
Thus  it  appears  that  the  absence  of  alteration  in  the  perceived  magnitude  of  an 
object  as  ordinarily  seen  at  varying  distances,  is  the  result  of  the  inverse  action 
of  these  two  kinds  of  suggestion ;  for  the  enlargement  of  the  retinal  picture,  when 
acting  alone,  occasions  an  increase  in  the  perceived  magnitude,  whilst  an  increase 
of  convergence,  taking-place  by  itself,  diminishes  the  perceived  magnitude ;  and 
thus,  as  these  alterations  occur  simultaneously  when  an  object  is  approximated 
to  the  eye,  its  dimensions  seem  to  undergo  no  change ;  as  will  also  be  the  case, 
when,  by  the  removal  of  the  object  to  a  greater  distance,  these  conditions  are 
again  made  to  vary  simultaneously,  though  in  a  contrary  direction. — It  may  fur 
tber  be  remarked,  that  in  the  first  of  the  foregoing  experiments,  the  picture  whose 
perceived  magnitude  is  undergoing  enlargement  or  diminution  in  consequence  of 
the  alteration  of  its  retinal  magnitude,  seems  evidently  to  be  approaching  and 


fi8i         OF    THE    ORGANS    OF   THE    SENSES,    AND   THEIR   FUNCTIONS. 

receding;  yet  if  we  fix  our  attention  on  it  when  it  is  stationary,  at  any  instant,  it 
appears  to  be  at  the  same  distance  at  one  time  as  at  another,  the  effect  being  very 
much  like  that  of  the  Phantasmagoria,  in  which  the  alteration  in  the  size  of  tho 
images  on  the  screen  suggests  the  notion  of  their  approach  or  recession,  although 
we  are  quite  sensible  that  the  distance  of  the  screen  from  our  eyes  remains  con- 
stantly the  same.  In  the  second  experiment,  on  the  other  hand,  the  picture 
whose  perceived  magnitude  is  undergoing  diminution  or  enlargement  in  conse- 
quence of  increase  or  lessening  of  the  angle  of  convergence,  does  not  appear  either 
to  approach  or  recede,  and  yet,  when  attentively  regarded  in  different  fixed  posi- 
tions, it  is  felt  to  be  at  different  distances.  Hence,  as  Prof.  Wheatstone  observes, 
convergence  of  the  optic  axes  suggests  fixed  distance  to  the  mind,  whilst  varia- 
tions of  retinal  magnitude  suggest  change  of  distance;  and,  however  paradoxical 
it  may  seem,  awe  may  perceive  an  object  approach  or  recede,  without  appearing 
to  change  its  distance,  and  an  object  to  be  at  a  different  distance  without  appear- 
ing to  approach  or  recede."1 — A  like  alteration  in  apparent  size  is  produced, 
when  two  pairs  of  figures  (such  as  those  given  in  Fig.  172),  the  effect  of  one  of 
which  is  to  suggest  a  projecting,  and  that  of  the  other  a  receding  form,  are  viewed 
at  the  same  time  in  the  ordinary  Stereoscope.  For  it  will  be  observed  that  the 
relative  size  of  the  parts  which  appear  to  project  is  reduced,  whilst  that  of  the 
apparently-receding  parts  is  augmented ;  as  is  particularly  the  case  with  the  square 
truncated  end  of  the  pyramid,  which  is  estimated  by  most  persons  as  from  one- 
third  to  one-half  larger  in  each  of  its  dimensions  in  the  receding,  than  it  is  in  the 
projecting  pyramid,  notwithstanding  that  the  actual  sizes  of  the  squares  in  the 
two  sets  of  figures  are  precisely  the  same.  For  supposing  H  I  (Fig.  173)  to  rep- 
resent the  real  side  of  one  of  the  small  squares,  which  becomes  the  truncated  end 
of  the  pyramid ;  when  this  is  brought-forward  by  the  mind  into  the  position  K  L, 
as  the  truncated  top  of  a  projecting  pyramid,  being  seen  under  the  visual  angle 
H  A  i,  its  apparent  size  is  reduced  to  r  G;  whilst,  on  the  other  hand,  the  very 
same  square,  carried-back  by  the  mind  to  the  distance  D  E,  as  when  it  forms  the 
truncated  end  of  the  receding  pyramid,  is  mentally  enlarged  to  the  dimensions  B 
C,  the  visual  angle  B  A  C  being  the  same  as  H  A  I. 

767.  The  large  share  which  the  Mind  has,  in  the  interpretation  of  even  such 
visual  impressions  as  seem  to  us  necessarily  to  induce  particular  perceptions,  ia 
further  shown  by  a  very  remarkable  class  of  phenomena,  termed  by  Prof.  Wheat- 
stone  (their  discoverer)  Conversions  of  Relief.  The  simplest  example  of  this 
class  is  presented  by  the  alteration  in  the  visual  product  of  the  same  Stereoscopic 
pictures,  when  their  positions  are  transposed.  Thus  the  very  same  diagrams, 
which,  as  placed  in  the  upper  part  of  Fig.  172,  bring  before  the  mind's  eye  the 
conception  of  a  projecting  pyramid,  when  changed  to  the  position  which  they  oc- 
cupy in  the  lower  part  of  that  figure,  call-up  the  image  of  a  receding  pyramid. 
And  a  corresponding  effect  is  produced  by  the  reversal  of  any  other  pair  of  Ste- 
reoscopic pictures;  all  that  should  project  being  made  to  recede,  all  that  should 
recede  being  made  to  project,  provided  the  converse  has  any  meaning  which  the 
Mind  can  readily  appreciate. — But  the  same  effects  may  be  produced,  if  the  ob- 
jects themselves  are  looked-at  by  an  instrument  devised  by  Prof.  Wheatstone, 
and' termed  by  him  the  Pseudoscope  ;  the  optical  effect  of  which  is,  to  reverse  the 
ordinary  visual  relations  between  the  near  and  distant  parts  of  an  object;  the  two 
conditions  described  in  the  preceding  paragraph  being  combined  inversely,  so 
that,  as  an  object  or  part  of  an  object  is  nearer  the  eye,  its  larger  picture  on  the 
retina  is  accompanied  by  a  diminished  convergence  of  the  optic  axes.  When  the 
impression  of  a  seal  is  looked-at  with  this  instrument,  it  is  converted  into  the  re- 
presentation of  the  seal  itself;  or,  if  the  seal  be  looked-at,  it  presents  the  figure 

*  See  "  Philos.  Transact.,"  1852,  pp.  2-5.  The  Author  thinks  it  well  to  add,  that  he 
has  himself  verified  the  above  very  curious  results;  which  are  scarcely  less  valuable  con- 
tributions to  the  Physiology  of  Binocular  vision,  than  those  earlier  attained  by  the  same 
eminent  experimentalist. 


SENSE    OF    VISION. — PERSISTENCE    OF    IMPRESSIONS.  685 

raised  in  relief,  as  in  its  ordinary  impression.     So,  the  inside  of  a  cup  or  basin 
appears  as  a  solid  convex  body  ;  whilst  the  outside  appears  depressed  and  concave. 
A  bust  regarded  in  front  becomes  a  deep  hollow  mask ;  whilst  the  interior  of  the 
cast  of  a  face  presents  the  appearance  of  the  face  in  its  ordinary  relief.     A  china 
vase,  ornamented  with  coloured  flowers  in  relief,  seems  like  a  vertical  section  of 
the  interior  of  such  a  vase,  with  hollow  impressions  of  the  flowers.     The  base  of 
a  brain  seems  concave,  like  the  interior  of  the  base  of  the  skull  which  is  its 
reflex;  and  the  latter  seems  convex  and  projecting,  like  the  base  of  the  brain. — 
These  and  similar  appearances  are  not  always  immediately  perceived ;  and  some 
present  themselves  much  more  readily  than  others.     Those  converse  forms  which 
we  are  accustomed  actually  to  see,  or  which  have  a  meaning  that  the  mind  can 
easily  apprehend,  are  those  which  are  most  readily  perceived.     Thus,  the  illusion 
which  may  be  produced  with  a  bust  or  with  the  cast  of  a  face,  is  not  easily  obtain- 
able even  by  a  lengthened  pseudoscopic  contemplation  of  the  real  face,  which  we 
can  scarcely  couceive-of  as  thus  '  turned  inside-out/     Another  very  interesting 
fact  is,  that  those  to  whom  the  illusion  does  not  at  first  present  itself,  usually  find 
it  suddenly  come  upon  them  after  a  little  time,  especially  if  they  should  havo 
directed  their  minds  to  the  imaginary  conception  of  the  object  under  its  changed 
aspect.     And,  further,  when  the  conversion  has  taken  place,  the  natural  aspect 
of  the  object  continues  to  intrude  itself,  sometimes  suddenly,  sometimes  gradu- 
ally, and  for  a  longer  or  shorter  interval,  when  the  converse  will  again  succeed 
it.     This  is  due  to  the  involuntary  alternation  of  the  attention,  between  the  con- 
ception suggested  to  the  mind  by  the  visual  impressions  derived  from  both  eyes, 
and  that  which  is  derived  from  either  eye  singly  (§  592),  the  latter,  moreover, 
harmonising-with  and  being  strengthened-by  our  recollection  of  the  object  as  we 
have  seen  it  before,  or  (if  it  be  new  to  us)  by  our  notion  of  its  natural  appearance. 
768.  The  persistence,  during  a  certain  interval,  of  impressions  made  upon  the 
retina,  gives-rise  to  a  number  of  curious  visual  phenomena,  which  can  be  here 
only  briefly  adverted-to.     The  prolongation  of  the  impression  will  be  governed, 
in  part,  by  its  previous  duration :  thus,  when  we  rapidly  move  an  ignited  point 
through  a  circle,  the  impression  itself  is  momentary,  and  remains  but  fora  short 
period ;  whilst,  if  we  have  been  for  some  time  looking  at  a  window,  and  then 
close  our  eyes,  the  impression  of  the  dark  bars  traversing  the  illuminated  space 
is  preserved  for  several  seconds.     One  of  the  results  of  this  persistence  is  the 
combination,  into  a  single  image,  of  two  or  more  objects  presented  to  the  eye  in 
successive  movements;  but  these  must  be  of  a  kind  which  can  be  united,  other- 
wise a  confused  picture  is  produced.     Thus  in  a  little  toy,  called  the  Thaumatrope, 
which  was  introduced  some  years  ago,  the  two  objects  were  painted  on  the  oppo- 
site sides  of  a  card, — a  bird,  for  instance,  on  one,  and  a  cage  on  the  other ;  and, 
when  the  card  was  made  (by  twisting  a  pair  of  strings)  to  revolve  about  one  of 
its  diameters,  in  such  a  manner  as  to  be  alternately  presenting  the  two  sides  to 
the  eye  at  minute  intervals,  the  two  pictures  were  blended,  the  bird  being  seen 
in  the  cage.     A  far  more  curious  illusion,  however,  was  that  first  brought  into 
notice  by  Prof.  Faraday;  who  showed  that,  if  two  toothed  wheels,  placed  one 
behind  the  other,  be  made  to  revolve  with  equal  velocity,  a  stationary  spectrum 
will  be  seen ;  whilst  if  one  be  made  to  revolve  more  rapidly  than  the  other,'  or 
the  number  .of  teeth  be  different,  the  spectrum  also  will  revolve.     The  same 
takes-place  when  a  single  wheel  is  made  to  revolve  before  a  mirror,  the  wheel 
and  its  image  answering  the  purpose  of  the  two  wheels  in  the  former  case.     On 
this  principle,  a  number  of  very  ingenious  toys  have  been  constructed ;  in  some 
of  these,  the  same  figure  or  object  is  seen  in  a  variety  of  positions;  and  the 
successive  impressions,  passing  rapidly  before  the  eye,  give-rise  by  their  combi- 
nation to  the  idea,  that  the  object  is  itself  moving  through  these  positions.1 — It 

1  A  very  beautiful  'philosophical  toy'  was  shown  to  the  Author  some  years  since,  by  its 
inventor,  Mr.  Roberts,  the  celebrated  machinest  of  Manchester ;  consisting  in  an  apparatus 
by  which  it  was  made  possible  to  read  words  printed  on  a  card,  although  the  card  itself 


686     OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

is  interesting  to  remark,  moreover,  that  when  the  eye  has  been  for  some  time 
contemplating  an  object  in  motion,  and  is  then  directed  towards  stationary  ob- 
jects, these  appear  for  a  short  time  to  have  a  like  movement.  Any  rail-road 
traveller  may  try  this  simple  experiment,  by  first  looking  at  the  hedges,  &c., 
which  he  is  rapidly  passing,  and  then  at  some  part  of  the  interior  of  the  carriage 
itself,  especially  one  which  presents  a  series  of  parallel  lines.  But  when  the 
impression  of  movement  has  been  of  longer  duration,  its  effects  are  less  transient; 
thus,  a  person  who  has  been  for  some  time  on  board  ship,  sees  the  floors,  walls, 
and  ceilings  of  his  apartments  on  shore  in  a  state  of  continual  up-and-down 
motion,  even  for  some  days  after  he  has  landed.  This  would  seem  to  be  rather  a 
sensorial  than  a  retinal  phenomenon. 

769.  When  the  Retina  has  been  exposed  for  some  time  to  a  strong  impression 
of  some  particular  kind,  it  seems  less  susceptible  of  feebler  impressions  of  the 
same  kind.  Thus,  if  we  look  at  any  brightly  luminous  object,  and  then  turn  our 
eyes  on  a  sheet  of  white  paper,  we  shall  perceive  a  dark  spot  upon  it ;  the  por- 
tion of  the  retina  which  had  been  affected  by  the  bright  image,  not  being  able 
to  receive  an  impression  from  the  fainter  rays  reflected  by  the  paper.  The  dark 
spectrum  does  not  at  once  disappear,  but  assumes  different  colours  in  succession, 
— these  being  expressions  of  the  states  through  which  the  retina  is  passing,  in 
its  transition  to  the  natural  condition.  If  the  eye  has  received  a  strong  impres- 
sion from  a  coloured  object,  the  spectrum  exhibits  the  complementary  colour;* 
thus,  if  the  eye  be  fixed  for  any  length  of  time  upon  a  bright  red  spot  on  a  white 
ground,  and  be  then  suddenly  turned  so  as  to  rest  upon  the  white  surface,  we 
see  a  spectrum  of  a  green  colour. — The  same  explanation  applies  to  the  curious 
phenomenon  of  '  coloured  shadows/  It  may  not  unfrequently  be  observed  at 
sunset,  that,  when  the  light  of  the  sun  acquires  a  bright  orange  colour  from  the 
clouds  through  which  it  passes,  the  shadows  cast  by  it  have  a  blue  tint.  Again, 
in  a  room  with  red  curtains,  the  light  which  passes  through  these  produces  green, 
shadows.  In  both  instances,  a  strong  impression  of  one  colour  is^  made  on  the 
general  surface  of  the  retina ;  and  at  any  particular  spots,  therefore,  at  which, 
the  light  is  colourless  but  very  faint,  that  colour  is  not  perceived,  its  complement 
only  being  visible.  The  correctness  of  this  explanation  is  proved  by  the  fact, 
that,  if  the  shadow  be  viewed  through  a  tube,  in  such  a  manner  that  the  coloured 
ground  is  excluded,  it  seems  like  an  ordinary  shadow.  It  is  not  unlikely  that, 
as  Miiller  suggests,  the  predominant  action  of  one  colour  on  the  retina  disturbs 
(as  it  were)  the  equilibrium  of  its  condition,  and  excites  in  it  a  tendency  to  the 
development  of  a  state  corresponding  to  that  which  is  produced  by  the  impression 
of  the  complementary  colour ;  for  the  latter  is  perceived,  as  he  remarks,  even 
where  it  does  not  exist ;  as  when  the  eye,  after  receiving  a  strong  impression 
from  a  coloured  spot,  and  being  directed  upon  a  completely  dark  surface  or  into 
a  dark  cavity,  still  perceives  the  spectrum.  This  change,  indeed,  extends  beyond 
the  spot  on  which  the  impression  is  made  (§  771);  for,  as  is  well  known  to 
Artists,  the  sensory  impression  produced  by  any  colour  is  greatly  affected  by 
neighbouring  hues.  Thus,  if  four  strips  of  coloured  paper,  or  any  other  fabric, 
A,  B,  c,  D, — two  of  them,  A,  B,  of  one  colour  (e.  y.  red),  and  the  other  two,  c,  D, 

was  made  to  revolve  on  its  axis  even  40,000  times  in  a  minute.  The  principle  of  its  con- 
struction was  simply  this, — that  the  eye  caught  a  succession  of  glimpses  of  the  card, 
through  a  narrow  slit  before  which  a  disk  with  a  single  corresponding  perforation  was 
made  to  revolve ;  the  rate  of  movement  of  this  disk  being  so  adjusted  to  that  of  the  card, 
that  whenever  the  eye  caught  sight  of  the  latter,  it  was  momentarily  in  the  same  position, 
so  that,  by  the  succession  of  transient  impressions  thus  made  upon  the  retina,  the  words 
printed  on  the  card  could  be  distinctly  read. 

1  By  the  '  complementary'  colour  is  meant  that  which  would  be  required  to  make  white 
or  colourless  light,  when  mixed  with  the  original.  As  red,  blue,  and  yellow  are  the 
primary  or  elementary  colours,  red  is  the  complement  of  green  (which  is  composed  of  yel- 
low and  blue) ;  blue  is  the  complement  of  orange  (red  and  yellow)  ;  and  yellow  of  purple 
''red  and  blue)  :  and  vice  versd,  in  all  instances. 


SENSE  OP  VISION:  —  COMPLEMENTARY  COLOURS.     687 

of  some  different  colour  (e.  g.  blue), — be  laid  side-by-side  at  intervals  of  aboui 
half  an  inch,  the  hues  of  the  two  central  strips  B,  c,  will  be  decidedly  modified 
by  each  other's  proximity,  each  approximating  to  the  hue  of  the  complementary 
colour  of  the  other ;  so  that  instead  of 

A  B  CD 

red  red  blue  blue 

we  shall  see 

A  B  CD 

red  orange-red        greenish-blue        blue. 

770.  Upon  the  properties  of  the  Eye  in  regard  to  Colour,  are  founded  the 
laws  of  harmonious  colouring,  which  have  an  obvious  analogy  with  those  of 
musical  harmony.     All  complementary  colours  have  an  agreeable  effect,  when 
judiciously  disposed  in  combination ;  and  all  bright  colours,  which  are  not  com- 
plementary, have  a  disagreeable  effect,  if  they  are  predominant :  this  is  especially 
ihe  case  in  regard  to  the  simple  colours,  strong  combinations  of  any  two  of  which, 
without  any  colour  that  is  complementary  to  either  of  them,  are  extremely  offen- 
sive.    Painters  who  are  ignorant  of  these  laws,  introduce  a  large  quantity  of  dull 
grey  into  their  pictures,  in  order  to  diminish  the  glaring  effects  which  they  would 
otherwise  produce  j  but  this  benefit  is  obtained  by  a  sacrifice  of  the  vividness 
and  force,  which  may  be  secured  in  combination  with  the  richest  harmony,  by  a 
proper  attention  to  physiological  principles.1 — Some  persons  whose  visual  powers 
are  excellent  in  every  other  respect,  are  more  or  less  deficient  in  the  power  of 
discriminating  colours.     This  defect  (which  is  now  commonly  known  as   t  Dal- 
tonism/ from  the  name  of  the  distinguished  philosopher  who  was  himself  the 
subject  of  it)  may  be  so  complete,  that  nothing  can  be  perceived  save  different 
degrees  of  light  and  shadow ;  more  commonly,  however,  it  exists  only  with  re- 
gard to  particular  colours,  especially  such  as  have  a  complementary  relation  to 
one  another,  so  that  persons  thus  affected  are  unable  (e.  g.)  to  distinguish  ripe 
cherries  among  the  leaves  of  the  tree,  save  by  their  form  j  whilst  in  some  indi- 
viduals it  does  no  more  than  confuse  colours  that  are  nearly  related,  such  as  green 
and  blue,  especially  when  they  are  seen  by  artificial  light.     Whether  its  seat  be 
in  the  nervous  apparatus  of  the  Eye,  or  in  the  Sensorium,  cannot  be  positively 
determined ;  but  the  latter  seems  the  most  probable  supposition.2 

771.  The  impressions  made  by  luminous  objects-  upon  the  Retina,  are  not  pre- 
cisely confined  to  the  spots  upon  which  their  rays  impinge,  but  extend  themselves  to 
a  greater  or  less  distance  around \  which  phenomenon  has  been  termed  irradiation. 
Thus  if  we  make  a  circular  white  spot  upon  a  black  ground,  and  a  black  spot  of 
precisely  the  same  dimensions  upon  a  white  ground,  the  former  will  seem  to  be 
considerably  larger  than  the  latter;    apparently  because  the  excitation  of  the 
retina  by  the  luminous  impression  tends  to  spread  itself  in  each  case  over  the 
adjacent  non-excited  space.     Hence  it  is  that  we   are  able  to  distinguish  any 
small  magnitudes,  such  as  letters  or  the  lines  of  a  diagram,  at  a  much  greater 
distance,  when  they  are  marked  in  white  on  a  black  ground,  than  when  inscribed 
in  black  upon  a  white  ground.     Another  curious  case  of  the  same  kind  has  been 
noticed  by  Sir  D.  Brewster.3     "If  we  shut  one  eye,  and  direct  the  other  to  any 
fixed  point,  such  as  the  head  of  a  pin,  we  shall  see  indistinctly  all  other  objects 
within  the  sphere  of  vision.     Let  one  of  these  objects  thus  indistinctly  seen,  be 
a  strip  of  white  paper  or  a  pen  lying  on  a  green  cloth.     Then,  after  a  short  time, 
the  strip  of  paper,  or  the  pen,  will  disappear  altogether,  as  if  it  were  entirely 

1  This  subject  has  been  most  carefully  and  elaborately  investigated  by  M.  Chevreul ; 
whose  recent  Treatise  on  Colours  has  almost  exhausted  the  enquiry  into  the  mode  in  which 
the  Visual  sense  of  Man  is  affected  by  them. 

8  See  especially  the  Memoir  of  Prof.  Seebeck,  in  "  Poggendorf  s  Annalen,"  band  xlii. 
(1837) ;  and  that  of  Prof.  Wartmann  in  "  Taylor's  Scientific  Memoirs,"  vol.  iv.  p.  156. 

1  "  Treatise  on  Optics,"  in  Lardner's  Cyclopaedia,  p.  296. 


688    OF  THE  ORGANS  OF  THE  SENSES,  AND  THEIR  FUNCTIONS. 

removed ;  the  impression  of  the  green  cloth  upon  the  surrounding  parts  of  the 
retina,  extending  over  that  part  of  it  which  the  image  of  the  pen  occupied.  In 
a  short  time  the  vanished  image  will  re-appear,  and  again  vanish  :  when  both 
eyes  are  open,  the  very  same  effect  takes  place,  but  not  so  readily  as  with  one 
eye.  If  the  object  seen  indistinctly  is  a  black  stripe  on  a  white  ground,  it  will 
vanish  in  a  similar  manner.  When  the  object  seen  obliquely  is  luminous,  such 
as  a  candle,  it  will  never  vanish  entirely,  unless  its  light  is  much  weakened  by 
being  placed  at  a  great  distance ;  but  it  swells  and  contracts,  and  is  encircled  by 
a  nebulous  halo." 

772.  The  power  of  receiving  and  transmitting  visual  impressions  is  by  no 
means  uniformly  diffused  over  the  entire  Retina.  In  the  whole  field  of  vision 
which  at  any  time  lies  before  us,  we  only  see  with  perfect  distinctness  that  part 
to  which  the  axes  of  our  eyes  are  directed,  and  of  which  the  image,  therefore, 
is  formed  upon  the  ( yellow  spot '  (§  755).  Nevertheless  we  have  a  sufficiently 
distinct  perception  of  the  remainder  of  the  field,  to  enable  us  to  judge  of  the 
relations  of  the  objects  which  are  distinctly  seen,  to  those  which  surround  them; 
and  the  mobility  of  our  eyes  enables  us,  under  the  guidance  of  our  visual  sense 
(§  546),  to  direct  the  most  sensitive  spot  of  the  retina  to  every  part  of  the  field 
in  succession,  not  only  without  effort,  but  even  almost  without  the  consciousness 
that  we  are  doing  so. — Generally  speaking,  the  indistinctness  of  vision  for  objects 
seen  out  of  the  axis  of  the  eye,  increases-with  the  distance  of  their  images  from 
the  central  point;  or,  in  other  words,  the  impressibility  of  the  several  parts  of 
the  retina  diminishes,  according  to  their  distance  from  the  '  yellow  spot/  But 
there  is  one  part  of  the  retinal  surface,  namely,  the  seat  of  entrance  of  the  Optic 
Nerve,  which  is  remarkable  for  its  imperfect  receptivity;  as  is  shown  by  the  fol- 
lowing experiment.  Let  two  black  spots  be  made  upon  a  piece  of  paper,  about 
four  or  five -inches  apart;  then  let  the  left  eye  be  closed,  and  the  right  eye  be 
strongly  fixed  upon  the  left-hand  spot;  if  the  paper  be  then  moved  backwards 
and  forwards,  so  as  to  change  its  distance  from  the  eye,  a  point  will  be  found  at 
which  the  right-hand  spot  is  no  longer  visible,  though  it  is  clearly  seen  when  the 
paper  is  brought  nearer  or  removed  further.  In  this  position  of  the  eye  and 
the  object,  the  rays  from  the  right-hand  spot  cross  to  the  nasal  side  of  the  globe, 
and  fall  upon  the  point  of  the  retina  which  has  just  been  mentioned.  If  the 
same  experiment  be  tried  with  candles,  the  image  will  not  entirely  disappear,  but 
will  become  a  cloudy  mass  of  light.  It  is  not  correct  to  say,  as  is  sometimes 
done,  that  the  retina  is  not  impressible  by  light  at  this  point ;  since,  if  such 
were  the  case,  we  should  see  a  dark  spot  in  our  field  of  view  whenever  we  use 
only  one  eye,  which  is  not  the  case.  The  fact  seems  rather  to  be,  that  this  por- 
tion of  the  retina  is  very  inferior  to  the  surrounding  parts  in  its  receptivity  for 
luminous  impressions ;  whilst,  on  the  other  hand,  there  is  an  unusual  tendency 
to  the  extension  of  their  condition  to  it  by  '  irradiation '  (§  771);  so  that,  in  the 
experiment  just  described,  if  the  black  spots  be  made  upon  a  coloured  ground, 
this  colour  will  take  the  place  of  the  spot  which  disappears. 

773.  The  impression  made  by  rays  of  light  upon  the  Retina,  may  be  to  a  cer- 
tain extent  imitated  by  other  physical  agencies  (§  731),  which  thus  give  rise  to 
various  subjective  visual  phenomena.  Advantage  has  recently  been  taken  by  Dr. 
Serre,1  of  the  power  of  mechanical  pressure  to  produce  luminous  spectra,  for  the 
investigation  of  the  *  law  of  visual  direction '  (§  759) ;  and  the  results  which  he 
has  obtained  are  of  very  great  interest.  When  any  part  of  the  globe  of  the  eye 
is  compressed  (the  experimenter  being  in  a  completely-darkened  room),  a  lumi- 
nous figure  is  seen  to  be  projected  in  the  direction  opposite  to  the  spot  pressed- 
upon.  Its  form  varies  according  to  that  of  the  compressing  body,  and  to  the  de- 
gree in  which  the  retina  is  affected  by  it.  Thus  if  the  pressure  be  made  by  the 
point  of  the  finger,  or  by  any  other  circular  surface,  upon  a  part  of  the  globe  over 
the  interior  of  which  the  retina  is  continuous,  the  spectrum,  or  phosphene  (as  it  is 
1  See  his  "  Essai  sur  les  Phosphenes,"  Paris,  ]853. 


SENSE    OF    VISION  : — SUBJECTIVE    PHENOMENA.  689 

termed  by  Dr.  Serre),  is  also  circular  j  if  the  compressing  body,  on  the  other 
hand,  be  square  at  its  extremity,  the  f  phosphene '  is  also  square ;  and  if  it  be  tri- 
angular, the  ' phosphene7  is  triangular  too.  But  if  the  pressure  be  made  near 
the  anterior  edge  of  the  retina  (which  is  what  most  commonly  happens,  unless  the 
most  favourable  situation  be  designedly  chosen),  the  figure  of  the  '  phosphene  '  is 
incomplete;  and  the  degree  of  its  deficiency  corresponds  with  the  proportion  of 
the  area  of  compression  that  does  not  lie-over  the  retinal  expansion.  Hence  there 
can  be  no  hesitation  in  regarding  the  production  of  this  spectrum  as  the  imme- 
diate result  of  the  affection  of  the  sensoriuin  by  the  pressure  on  the  retina;  and  as 
it  seems  to  our  perceptive  consciousness  to  have  a  distinct  objective  existence, 
and  as  its  position  bears  a  constant  and  definite  relation  to  that  of  the  portion  of 
the  retina  on  which  the  impression  is  made,  it  seems  %obvious  that  any  such  affec- 
tion of  the  retina  not  only  intuitively  suggests  to  our  minds  the  notion  of  an  ex- 
ternal objective  cause  of  the  impression,  but  also  indicates  to  our  consciousness 
the  direction  of  the  object. — But  further,  besides  the  principal  'phosphene/  an- 
other, of  smaller  dimensions,  is  usually  to  be  seen,  in  a  direction  nearly  the  same 
as  that  on  which  the  pressure  is  made;  this  is  the  result  of  the  transmission  of 
the  pressure  to  the  opposite  side  of  the  globe,  by  an  alteration  of  its  figure  and  of 
the  position  of  its  contents,  which  corresponds  to  the  fracture  of  the  skull  by 
contre-coup.  The  form  of  this  smaller  or  secondary  c  phosphene '  is  not  affected 
by  the  cause  which  sometimes  renders  the  larger  or  primary  spectrum  incomplete; 
since,  as  we  cannot  anywhere  apply  pressure  to  the  living  Human  eye,  save  on 
some  part  of  its  anterior  hemisphere,  the  '  contre-coup '  will  always  take-place  at 
the  opposite  spot  in  the  posterior  hemisphere,  over  which  the  retina  is  continuous, 
save  at  the  entrance  of  the  optic  nerve.  By  an  extensive  series  of  observations 
upon  the  relation  of  the  positions  of  the  primary  and  secondary  f  phosphenes/  both 
to  each  other  and  to  the  seat  of  compression,  Dr.  Serre  has  deduced  the  important 
conclusion,  that  the  lines  joining  the  imaginary  spectra  and  the  spots  of  the  re- 
tina from  whose  affection  they  respectively  proceed,  pass  through  a  common 
4  centre  of  direction/  whose  position  is  in  the  middle  of  the  crystalline  lens. 
And  hence  it  seems  to  be  a  legitimate  conclusion,  that  our  sense  of  the  relative 
directions  of  external  objects  is  derived  from  a  kind  of  mental  projection  of  each 
point  of  the  retinal  image,  in  the  line  which  joins  it  to  this  '  centre  of  direction/ 
774.  Another  very  curious  subjective  phenomenon  of  Vision,  id  the  representa- 
tion which,  under  particular  circumstances,  we  may  mentally  obtain  of  the  retina 
itself;  as  in  the  following  experiment,  first  devised  by  Purkinje,  and  known  by 
his  name.  u  If  in  a  room  otherwise  dark,  a  lighted  candle  be  moved  to  and  fro, 
or  in  a  circle,  at  a  distance  of  six  inches  before  the  eyes,  we  perceive,  after  a 
short  time,  a  dark  arborescent  figure  ramifying  over  the  whole  field  of  vision ;  this 
appearance  is  produced  by  the  vasa  centralia  distributed  over  the  retina,  or  by  the 
parts  of  the  retina  covered  by  those  vessels.  There  are,  properly  speaking,  two 
arborescent  figures,  the  trunks  of  which  are  not  coincident,  but  on  the  contrary 
arise  in  the  right  and  left  divisions  of  the  field,  and  immediately  take  opposite 
directions.  One  trunk  belongs  to  each  eye,  but  their  branches  intersect  each 
other  in  the  common  field  of  vision.  The  explanation  of  this  phenomenon  is  as 
follows : — By  the  movement  of  the  candle  to  and  fro,  the  light  is  made  to  act  on 
the  whole  extent  of  the  retina,  and  all  the  parts  of  the  membrane  which  are  not 
immediately  covered  by  the  vasa  centralia  are  feebly  illuminated ;  those  parts,  on 
the  contrary,  which  are  covered  with  those  vessels,  cannot  be  acted-on  by  the 
light,  and  are  perceived,  therefore,  as  dark  arborescent  figures.  These  figures 
appear  to  lie  before  the  eye,  and  to  be  suspended  in  the  field  of  vision."1  We 
have  thus  another  demonstration  of  the  fact,  that,  in  ordinary  Vision,  the  imme- 
diate object  of- our  sensation  is  a  certain  condition  of  the  retina,  which  is  excited 
by  the  formation  of  a  luminous  image. 

1  Muller's  "Elements  of  Physiology"  (Baly's  Translation),  p.  1163. 

44 


690         OF   THE   ORGANS    OF   THE   SENSES   AND    THEIR   FUNCTIONS. 

775.  The  Visual  power  is  susceptible  of  extraordinary  improvement,  through 
the  habitual  direction  of  our  attention  to  the  effects  produced  upon  our  conscious- 
ness by  the  impressions  transmitted  to  the  Sensorium  from  the  Eye ;  and  this 
improvement  may  take  place  either  in  regard  to  the  quickness  and  readiness  with 
which  objects  generally  are  perceived,  or  in  the  faculty  of  discriminating  the 
slightest  differences  in  form,  shade,  colour,  &c.,  or  of  discerning  bodies  of  extreme 
minuteness.  In  regard  to  all  these  points  it  may  be  noticed,  that  the  habit  of 
attention  to  any  particular  class  of  objects,  sharpens  the  discriminating  power  for 
that  class  alone;  and  that  it  is  usually  rather  the  mental  than  the  corporeal 
vision  which  undergoes  improvement.  Thus  the  Seaman  who  makes-out  the 
'  loom  of  the  land '  where  the  landsman  can  discern  nothing  but  an  indefinite 
haze  above  the  horizon,  or  who  can  distinguish  the  size,  rig,  and  course  of  a 
vessel,  which  the  landsman  can  but  see  as  a  formless  speck,  does  so  in  virtue  of 
the  aptitude  of  his  mind  for  receiving  suggestions  from  minute  indications,  such 
as  pass  unnoticed  by  those  who  have  not  been  accustomed  to  form  their  ideas 
upon  the  same  kind  of  experiences.  And  the  Microscopist  who  is  constantly  on 
the  outlook  for  the  various  forms  of  organic  structure  with  which  his  mind  is 
familiar,  discerns  these  without  difficulty  or  hesitation,  where  an  ordinary  observer 
sees  nothing  but  a  confused  jumble  of  tissue. — It  is  interesting  to  observe  that 
the  power  of  descrying  objects  at  vast  distances,  appears  to  be  hereditarily  pos- 
sessed by  two  races  of  men,  the  Mongols  of  Northern  Asia,  and  the  Hottentots 
of  Southern  Africa,  both  of  which  habitually  dwell  on  vast  plains,  that  seem  to 
stretch  without  limit  in  every  direction.  It  seems  probable  that  this  power  was 
in  the  first  instance  acquired  by  habit  in  each  case ;  and  that,  as  frequently  hap- 
pens with  acquired  peculiarities,  which  are  kept-up  by  constant  use  in  successive 
generations,1  it  has  become  fixedly  hereditary. 

6. — Sense  of  Hearing. 

776.  In  the  Ear,  as  in  the  Eye,  the  impressions  made  upon  the  sensory  nerve 
are  not  at  once  produced  by  the  body  which  originates  the  sensation ;  but  they 
are  propagated  to  it,  through  a  medium  capable  of  transmitting  them.  We  ob- 
viously take  cognisance  by  the  mind,  therefore,  not  of  the  sonorous  object,  but 
of  the  condition  of  the  auditory  nerve  ;  and  all  the  ideas  we  form  of  sounds,  as  to 
their  nature,  intensity,  direction,  &c.,  must  be  based  upon  the  changes  which  they 
produce  in  it.  The  complex  contrivances  which  we  meet- with  in  the  organ  of 
Hearing  among  higher  animals,  are  evidently  intended  to  give  them  greater  power 
of  discriminating  sounds,  than  is  possessed  by  the  lower  tribes ;  in  which  last  it 
is  reduced  to  a  form  so  simple,  that  it  may  be  questioned  whether  they  can  be 
said  to  possess  an  organ  of  hearing,  if  by  this  term  we  imply  anything  more  than 
the  mere  consciousness  of  sonorous  vibrations. — There  is  a  considerable  differ- 
ence, however,  between  the  Eye  and  the  Ear,  in  regard  to  the  special  purposes 
for  which  they  are  respectively  adapted.  In  the  former,  we  have  seen  that  the 
whole  object  of  the  instrument  is  to  direct  the  rays  of  light  received  by  it,  in  such 
a  manner,  as  to  occasion  them  to  fall  upon  the  expansion  of  the  optic  nerve  in 
similar  relative  positions,  and  with  corresponding  proportional  intensities,  to  those 
which  they  possessed  when  issuing  from  the  object.  We  have  no  reason  to  believe 
anything  of  this  kind  to  be  the  purpose  of  the  Ear;  indeed  it  would  be  inconsistent 
with  the  laws  of  the  propagation  of  sound.  Sonorous  vibrations  having  the  most 
various  directions,  and  the  most  unequal  rates  of  succession,  are  transmitted  by 
all  media  without  modification,  however  numerous  their  lines  of  intersection ; 
and  wherever  these  undulations  fall  upon  the  auditory  nerve,  they  must  cause 
the  sensation  of  corresponding  sounds.  Still  it  is  probable  that  some  portions  of 
the  complex  organ  of  hearing,  in  Man  and  in  the  higher  animals,  are  more 
adapted  than  others  to  receive  impressions  of  a  particular  character ;  and  that 
1  See  "  Princ.  of  Comp.  Physiol.,"  Am.  Ed.,  g  620. 


SENSE    OF    HEARING.  691 

thus  we  may  be  especially  informed  of  the  direction  of  a  sound  by  one  part  of 
the  organ,  of  its  musical  tone  by  another,  and  of  some  other  of  its  qualities  by  a 
third. 

777.  The  essential  part  of  an  Organ  of  Hearing  is  obviously  a  nerve,  endowed 
with  the  peculiar  property  of  receiving  sonorous  undulations,  and  of  transmitting 
their  effects  to  the  Sensorium.  This  nerve  is  spread-out  over  the  surface  of  a' 
delicate  membrane  which  lines  the  Vestibule  and  its  prolongations ;  and  this 
membrane  encloses  a  fluid,  which  is  the  medium  whereby  the  sonorous  vibrations 
received  through  the  external  ear,  are  communicated  to  the  nerve.  We  learn 
from  an  examination  of  the  comparative  structure  of  the  auditory  apparatus  in  the 
lower  animals,  and  from  the  study  of  its  development  in  the  higher,  that  the  part 
which,  being  most  constantly  present  and  being  also  the  earliest  in  its  develop- 
ment, may  be  considered  as  the  most  essential,  is  the  simple  Vestibular  cavity; 
which  exists  where  there  are  no  vestiges  either  of  Semicircular  Canals,  of  Coch- 
lea, or  of  Tympanic  apparatus.  Such  a  condition  presents  itself  in  some  of  the 
higher  Invertebrata  and  in  the  lowest  Fishes;  but  as  we  ascend  the  Vertebrated 
series,  we  find  the  semicircular  canals  growing  out  (as  it  were)  of  the  Vestibule 
in  Fishes,  a  tympanic  apparatus  superadded  in  Reptiles,  and  a  Cochlea  first  ac- 
quiring a  more  than  rudimentary  development  in  the  class  of  Birds,  although 
only  presenting  in  Mammalia  that  characteristic  form  from  which  it  derives  its 
name.1  Of  the  mode  in  which  the  ultimate  subdivisions  of  the  Auditory  nerve 
are  distributed  upon  the  lining  membrane  of  the  labyrinth,  it  does  not  yet  seem 

[Fi<j.  174. 


General  view  of  the  external,  middle,  and  internal  Ear,  as  seen  in  a  prepared  section  through 
a,  the  auditory  canal,  b.  The  tympanum  or  middle  ear.  c.  Eustachian  tube,  leading  to  the 
pharynx,  d.  Cochlea;  and  e.  Semicircular  canals  and  vestibule,  seen  on  their  exterior,  as 
brought  into  view  by  dissecting  away  the  surrounding  petrous  bone.  The  styloid  process 
projects  below;  and  the  inner  surface  of  the  carotid  canal  is  seen  above  the  Eustachian  tube. 
From  Scarpa.] 

possible  to  give  a  certain  account;  for  although  Wagner  and  others  have  repre- 
sented them  as  terminating  in  free  loops,  yet  more  careful  observation  has  ren- 
dered this  doubtful ;  and  the  general  analogy  between  the  simpler  forms  of  the 
auditory  and  of  the  visual  apparatus,  as  well  as  the  close  correspondence  which 

1  For  a  more  detailed  sketch  of  the  Comparative  Anatomy  of  the  Organ  of  Hearing,  see 
the  Author's  "Principles  of  Comparative  Physiology,"  Am.  Ed.,  \\  711-714 


692     OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS, 

[FlG.  179. 


A  highly  magnified  view  of  a  small  piece  of  the  Lamina  Spiralis,  showing  the  manner  in 
which  the  nerves  leave  their  Neurilemma  as  they  anastomose;  the  natural  size  of  the  piece  is 
seen  on  the  side  of  the  figure  :  1,  portion  of  the  auditory  nerve;  2,  2,  osseous  canals  in  the 
zona  ossea  of  the  lamina  spiralis ;  3,  3,  anastomoses  in  the  zona  mollis ;  4,  4,  the  neurilemma 
leaving  the  nervous  loops,- and  interlocking  to  form  the  layer  of  the  zona  membranacea.] 

exists  between  them  in  the  history  of  their  development  (the  organ  of  hearing, 
like  the  eye,  being  budded-off  from  its  sensory  ganglion,  §  911),  seem  to  indicate 

that  the  peripheral  expansion  of  the  audi- 
tory nerve  might  be  expected  to  have  a 
structure  analogous  to  that  of  the  retina. 
The  most  exact  observations  yet  made  on 
this  point,  seem  to  be  those  of  the  Mar- 
quis Corti l  on  the  Cochlear  nerve ;  but 
the  nature  of  the  different  parts  which  he 
,  describes,  is  far  from  being  clearly  appa- 
rent. This  nerve  passes-out  from  the 
modiolus  into  a  series  of  anastomosing 
canals  excavated  in  the  osseous  lamina 
spiralis ;  and  it  there  comes  into  relation 
with  a  band  of  vesicular  substance,  which 
lies  near  the  edge  of  the  lamina  along  its 
whole  length.  The  component  vesicles 
n  arc  elongated,  having  a  central  and  a 
peripheral  extremity;  by  the  former  they 
are  connected  with  the  fibres  of  the  coch- 
lear  nerve,  the  connecting  filaments  being 
destitute  (as  elsewhere)  of  the  double  con- 
tour, and  being  very  fragile ;  and  by  the 
latter  they  are  similarly  connected  with 
the  fibres  which  issue-forth  from  the  os- 
n.  oAr-;  seous  lamina,  to  be  distributed  upon  its 

Tympanic  surface  of  a,  portion  of  the  lamina  .          .  mu  .cu 

epiralisofthecat.  a.  Termination  of  the  coch-  membranous    continuation, 
lear  nerves  at  the  border  of  the  osseous  zone,  form    fasciculi,    which   traverse    the    mem- 
with  capillaries  ramifyrag  over  them.  6.  inner  branous    lamina    nearly    parallel    to    each 
clear  belt  or  the  membranous  zone.     c.  Mar-       v  j  n  •  r 

ginal  capillary  on  the  tympanic  surface,  d.  Other,  and  anastomose  Continually  With 
Pectinate  portion  of  the  membranous  zone,  one  another,  in  such  a  manner  as  to  pre- 
The  half-detached  fragment  on  the  opposite  sent  the  appearance  of  looped  termma- 

cdge  shows  its  mode  of  tearing,    e.  Outer  clear  ,-  A      *T  /-,     ,-     V 

belt  of  membranous  zone,  torn  from  the  coch-  tlons'  According  to  Cortl,  however,  the 
learis  muscle.  Magnified  300  diameters.]  fibres  really  pass-on  further,  losing  their 
'  See  his  Memoir  in  Kolliker  and  Siebold's  "Zeitschrift  fur  wissenschaftljche  Zoologie," 
1851,  band  iii.  heft  1 ;  also  Prof.  Kolliker's  "  Mikroskopische  Anatomie,"  band  ii.  \  289, 
an}  his  "  Handbook  of  Human  Histology"  (Syden.  Soc.  Edit,),  vol.  ii.  p.  407-413. 


SENSE  OF  HEARING  I — LAWS  OF  PROPAGATION  OF  SOUND.    693 

double  contour,  and  becoming  gradually  incorporated,  as  it  were,  with  the  sur- 
rounding tissue.1 

778.  In  order  to  gain  any  definite  idea  of  the  uses  of  different  parts  of  the 
Ear,  it  is  necessary  to  bear  in  mind  that  sounds  may  be  propagated  amongst  solid 
or  fluid  bodies  in  three  ways;  by  reciprocation,  by  resonance,  and  by  conduction. 
— 1.  Vibrations  of  reciprocation  are  excited  in  a  sounding  body,  when  it  is  capa- 
ble of  yielding  a  musical  tone  of  definite  pitch,  and  another  body  of  the  same 
pitch  is  made  to  sound  near  it.  Thus  if  two  strings  of  the  same  length  and  ten- 
sion be  placed  alongside  of  each  other,  and  one  of  them  be  sounded  with  a  violin- 
bow,  the  other  will  be  thrown  into  reciprocal  vibration ;  or  if  the  same  tone  be 
produced  near  the  string  in  any  other  manner,  as  by  a  flute  or  a  tuning-fork,  the 
same  effect  will  result. — 2.  Vibrations  of  resonance  are  of  somewhat  the  same 
character;  but  they  occur  when  a  sounding  body  is  placed  in  connection  with  any 
other,  of  which  one  or  more  parts  may  be  thrown  into  reciprocal  vibration,  even 
though  the  tone  of  the  whole  be  different,  or  it  be  not  capable  of  producing  a  defi- 
nite tone  at  all.  This  is  the  case,  for  example,  when  a  tuning-fork  in  vibration 
is  placed  upon  a  sound-board;  for  even  though  the  whole  board  have  no  definite 
fundamental  note,2  it  will  divide  itself  into  a  number  of  parts,  which  will  recipro- 
cate the  original  sound,  so  as  greatly  to  increase  its  intensity ;  and  the  same 
sound-board  will  act  equally  well  for  tuning-forks  of  several  different  degrees  of 
pitch.  When  a  smaller  body  is  used  for  resonance,  however,  it  is  essential  that 
there  should  be  a  relation  between  its  fundamental  note  and  that  of  the  sonorous 
body;  otherwise  no  distinct  resonance  is  produced.  Thus,  if  a  tuning-fork  in 
vibration  be  held  over  a  column  of  air  in  a  tube,  of  such  a  length  that  the  same 
note  would  be  given  by  its  vibration,  its  sound  will  be  reciprocated.  And  if  it 
be  held  over  a  pipe,  the  column  of  air  in  which  is  a  multiple  of  this,  the  column 
will  divide  itself  into  that  number  of  shorter  parts,  each  of  which  will  reciprocate 
the  original  sound,  and  the  total  action  will  be  one  of  resonance.  But  if  the 
length  of  the  pipe  bear  no  such  correspondence  with  the  note  sounded  by  the 
tuning-fork,  no  resonance  is  given  by  the  column  of  air  it  contains. — 3.  Vibra- 
tions of  conduction  are  the  only  ones,  by  which  sounds  can  strictly  be  said  to  be 
propagated.  These  are  distinguishable  into  various  kinds,  into  which  it  is  not 
requisite  here  to  inquire.  It  should  be  remarked,  however,  that  all  media,  fluid, 
liquid,  or  solid,  are  capable  of  transmitting  sound  in  this  manner;  a  vacuum 
being  the  only  space  through  which  it  cannot  pass.  The  transmission  is  usually 
much  more  rapid  through  solid  bodies,  than  through  liquid;  and  through  liquid, 
than  through  gaseous.  The  greatest  diminution  in  the  intensity  of  sound  is  usu- 
ally perceived,  when  a  change  takes-place  in  the  medium  through  which  it  is  pro 
pagated,  especially  from  the  aeriform  to  the  liquid. 

779.  The  detailed  application  of  these  principles  has  been  most  elaborately 
worked-out  by  Prof.  Miiller;  and  the  following  statement  of  what  may  be  regarded 
as  the  present  condition  of  our  knowledge  of  the  subject,  is  little  more  than  an 
abstract  of  the  results  of  his  experimental  investigations;  of  which  the  first  series 

1  Such,  also,  is  the  account  of  their  termination  given  by  Messrs.  Todd  and  Bowman, 
"  Physiological  Anatomy,"  p.  457,  Am.  Ed. 

2  The  fundamental  note  of  a  sonorous  body  is  the  lowest  tone  which  it  yields,  when  the 
whole  of  it  is  in  vibration  together.     By  dividing  the  body  into  two  or  more  distinct  parts, 
it  may  be  made  to  give  a  great  variety  of  sounds.     Thus,  if  a  stretched  string  be  divided 
by  a  bridge  into  two  equal  parts,  each  will  sound  the  8th  note  or  octave  above  the  funda- 
mental note.     If  it  be  divided  into  three  parts,  each  will  give  the  12th  above  the  funda- 
mental note;  if  into  four,  the  15th  or  double  octave  will  be  heard:  if  into  five,  the  17th  ; 
if  into  six,  the  19th;  if  into  seven,  the  20|th  (flat  seventh  above  the  second  octave);  if 
into  eight,  the  22nd  or  triple  octave.     A  string  forcibly  set  in  vibration  has  a  tendency  to 
sound  these  harmonies  with  the  fundamental  note,  by  spontaneous  division  into  several 
distinct  segments  of  vibration  :  as  may  be  easily  made  evident,  by  striking  one  of  the  lower 
keys  of  the  piano,  and  listening  to  the  sounds  heard  whilst  the  fundamental  note  is  lying 
away. 


694         OF    THE    ORGANS    OF   THE    SENSES,    AND   THEIR   FUNCTIONS. 

bears  specially  on  the  case  of  those  animals,  which,  living  immersed  in  water, 
receive  the  sonorous  undulations  through  that  medium.  The  labyrinth  of  such 
as  possess  a  distinct  organ  of  hearing,  is  either  entirely  enclosed  within  the  bones 
of  the  head,  as  in  the  Cephalopoda,  and  in  the  Cyclostome  and  Osseous  Fishes  ; 
or,  its  cavity  being  prolonged  to  the  surface  of  the  body,  it  is  there  brought  into 
communication  with  the  conducting  medium  by  means  of  a  membrane,  besides 
receiving  the  vibrations  through  the  medium  of  the  solids  of  the  body,  as  is  the 
case  in  Cartilaginous  Fishes  and  Crustacea : — I.  Sonorous  vibrations,  excited  in 
water,  are  imparted  with  considerable  intensity  to  solid  bodies. — u.  Sonorous 
vibrations  of  solid  bodies  are  communicated  with  greater  intensity  to  other  solid 
bodies  brought  in  contact  with  them,  than  to  water;  but  with  much  greater  inten- 
sity to  water,  than  to  atmospheric  air.— ill.  Sonorous  vibrations  are  communi- 
cated from  air  to  water  with  great  difficulty,  this  difficulty  very  much  exceeding 
that  with  which  they  are  propagated  from  one  part  of  the  air  to  another;  but 
their  transition  from  air  to  water  is  much  facilitated  by  the  intervention  of  a 
membrane  extended  between  them. — iv.  Sonorous  vibrations  are  not  only  im- 
parted from  water  to  solid  bodies  with  definite  surfaces  which  are  in  contact  with 
the  water,  but  are  also  returned  with  increased  intensity  by  these  bodies  to  the 
water;  so  that  the  sound  is  heard  loudly  in  the  vicinity  of  those  bodies,  in  situ- 
ations where,  if  it  had  its  origin  in  the  conducting  power  of  the  water  alone,  it 
would  be  faint. — v.  Sonorous  undulations,  propagated  through  water,  are  partially 
reflected  by  the  surfaces  of  solid  bodies. — vi.  Thin  membranes  conduct  sound  in 
water  without  any  loss  of  its  intensity,  whether  they  be  tense  or  lax. — VII.  When 
sonorous  vibrations  are  communicated  from  water,  to  air  inclosed  in  membranes 
or  solid  bodies,  a  considerable  increase  in  the  intensity  of  the  sound  is  produced, 
by  the  resonance  of  the  air  tfms  circumscribed. — vm.  A  body  of  air  inclosed  in 
a  membrane,  and  surrounded  by  water,  also  increases  the  intensity  of  the  sound 
by  resonance,  when  the  sonorous  undulations  are  communicated  to  it  by  a  solid 
body. 

780.  Animals  living  in  air  are  nearly  always  provided  with  an  opening  into  the 
Vestibule,  the  fenestra  ovalis,  covered  by  a  thin  membrane  ;  and  generally  with  a 
Tympanic  apparatus  also.  The  following  experimental  results  bear  upon  the 
manner  in  which  the  Ear  of  such  animals  is  affected  by  sound : — IX.  Sonorous 
undulations,  in  passing  from  air  directly  into  water,  suffer  a  considerable  diminu- 
tion in  their  strength ;  while,  on  the  contrary,  if  a  tense  membrane  exist  between 
the  air  and  the  water,  the  sonorous  undulations  are  communicated  from  the  for- 
mer to  the  latter  medium  with  great  intensity. — x.  The  sonorous  vibrations  are 
also  communicated,  without  any  perceptible  loss  of  intensity,  from  the  air  to  the 
water;  when,  to  the  membrane  forming  the  medium  of  communication,  there  is 
attached  a  short  solid  body,  which  occupies  the  greater  part  of  its  surface,  and  is 
alone  in  contact  with  the  water. — XI.  A  small  solid  body,  fixed  in  an  opening 
by  means  of  a  border  of  membrane,  so  as  to  be  moveable,  communicates  sonorous 
vibrations,  from  air  on  one  side,  to  water  or  the  fluid  of  the  labyrinth  on  the 
other,  much  better  than  solid  media  not  so  constructed.  But  the  propagation  of 
sound  to  the  fluid  is  rendered  much  more  perfect,  if  the  solid  conductor,  thus 
occupying  the  opening,  is  by  its  other  end  fixed  to  the  middle  jof  the  tense  mem- 
brane, which  has  atmospheric  air  on  both  sides. — The  fact  stated  in  ix.  is  evi- 
dently one  of  great  importance  in  the  physiology  of  hearing;  and  fully  explains 
the  nature  of  the  process  in  those  animals,  which  receive  the  sonorous  vibrations 
through  air,  but  which  have  no  tympanic  apparatus.  In  x.  we  have  the  eluci- 
dation of  the  action  of  the  fenestra  ovalis,  and  of  the  moveable  plate  of  the  stapes 
which  occupies  it,  in  animals  living  in  air  but  destitute  of  tympanic  apparatus ; 
this  is  naturally  the  case  in  many  Amphibia;  and  it  may  happen  as  the  result  of 
disease  in  the  Human  subject.  In  xi.  we  have  a  very  interesting  demonstration 
of  the  purpose  and  action  of  the  tympanum,  in  the  more  perfect  forms  of  the 
auditory  apparatus. — We  are  now  prepared  to  inquire,  in  somewhat  more  of  de- 


SENSE  OF  HEARING: — USES  OF  TYMPANIC  APPARATUS.        695 

tail,  into  the  actions  of  the  different  parts  of  this  apparatus ;  and  it  will  be  better 
to  commence  with  those  of  the  Middle  and  Internal  Ear,  the  accessory  organs 
being  afterwards  considered. 

781.  The  Membrana  Tympani  consists  of  three  layers;  an  external  one  con- 
tinuous with  the  cutis  of  the  external  meatus,  and  consisting  of  dermoid  tissue 
with  a  covering  of  epidermic  cells;  an  internal,  which  is  extremely  thin,  continu- 
ous in  like  manner  with  the  mucous  membrane  lining  the  tympanic  cavity,  and 
also  composed  of  dermoid  tissue  and  epithelium ;  and  a  middle  layer,  which,  ac- 
cording to  Mr.  Toynbee,1  may  be  separated  into  two  distinct  laminae,  whose  fibres 
run  in  contrary  directions,  those  of  the  external  layer  (which  is  the  stronger  of 
the  two)  radiating  from  the  malleus  towards  the  peripheral  ring  to  which  they 
are  attached,  whilst  those  of  the  internal 

are  annular.     The  fibres  of  which  these  [FIG.  177. 

laminae  are  composed,  do  not  appear  to 
be  muscular;  nor  do  they  present  the  lon- 
gitudinal parallel  wavy  lines  characteris- 
tic of  ordinary  fibrous  membranes;  and 
they  are  rendered  opaque  by  acetic  acid. 
Hence,  although  those  laminae  appear  to 
be  derived,  the  external  from  the  perios- 
teum of  the  meatus,  and  the  internal 
from  that  of  the  tympanic  cavity,  they  Membrana  tympani  from  the  outer  (A)  and 
differ  from  it  m  elementary  Structure,  from  the  inner  (B)  sides :  1.  Membrana  tyin. 

and  seem  to  have  more  in  common  with    pani.    2.  Malleus.    3.  Stapes.    4  Incus.] 
the  elastic  tissue.     Mr.  Toynbee  points 

out  the  existence  of  a  tubular  ligament,  enclosing  the  tendon  of  the  tensor  tym- 
pani muscle ;  and  considers  that  the  membrane  is  maintained  by  this  ligament  in 
a  state  of  moderate  tension,  the  assistance  of  the  muscle  being  only  required  to 
augment  this. — The  function  of  the  Membrana  Tympani  seems  obviously  to  be 
the  reception  of  sonorous  undulations  from  the  air,  in  such  a  manner  that  it  may 
be  thrown  by  them  into  a  reciprocal  vibration,  which  is  communicated  to  the 
chain  of  bones.  In  its  usual  state,  this  membrane  is  scarcely  on  the  stretch ;  and 
this  is  found  by  experiment  to  be,  for  a  small  membrane,  the  best  condition  for 
the  propagation  of  ordinary  undulations.  This  is  easily  rendered  sensible  in 
one's  own  person ;  for  an  increased  tension  may  be  given  to  the  membrana  tym- 
pani, either  by  holding  the  breath  and  forcing  air  into  the  Eustachian  tube,  so 
as  to  distend  it  from  within,  or  by  exhausting  the  cavity,  so  as  to  cause  the  ex- 
ternal air  to  make  increased  pressure  upon  it ;  and  in  either  case,  the  hearing  is 
immediately  found  to  become  indistinct.  It  is  observed,  however,  that  grave  and 
acute  sounds  are  not  equally  affected  by  this  action ;  for  the  experimenter  renders 
himself  deaf  to  grave  sounds,  whilst  acute  sounds  are  heard  even  more  distinctly 
than  before.  This  fact  is  readily  understood,  by  referring  to  the  laws  of  Acous- 
tics already  mentioned.  The  greater  the  tension  to  which  the  membrana  tym- 
pani is  subjected,  the  more  acute  will  be  its  fundamental  tone;  and  as  no  proper 
reciprocation  can  take-place  in  it,  to  any  sound  lower  than  its  fundamental  tone, 
its  power  of  repeating  perfectly  the  vibrations  proper  to  the  deeper  notes  will 
diminish.  The  nearer  a  sound  approaches  to  the  fundamental  note  proper  to  the 
tense  membrane,  the  more  distinctly  will  it  be  heard.  On  the  other  hand,  when 
the  membrane  is  in  its  naturally-relaxed  condition,  its  fundamental  note  is  very 
low,  and  it  is  capable  of  repeating  a  much  greater  variety  of  sounds ;  for,  when  it 
receives  undulations  of  a  higher  tone  than  those  to  which  the  whole  membrane 
would  reciprocate,  it  divides  itself  into  distinct  segments  of  vibration,  which  are 
separated  by  lines  of  rest;  and  every  one  of  these  reciprocates  the  sound,2  at  the 

1  "  Philosophical  Transactions,"  1851. 

a  This  is  very  easily  proved  by  experiment  on  a  membrane  stretched  over  a  resonant 
cavity ;  for  if  light  sand  be  strewed  upon  it,  and  a  strong  musical  tone  be  produced  in  its 


[Fio.  178. 

771 


6 06         OF   THE    ORGANS    OF   THE    SENSES,    AND    THEIR    FUNCTIONS. 

same  time  rendering  it  more  intense  by  multiplication  (§  778).  These  facts  en- 
able us  to  understand  the  influence  of  the  tensor  tympani  muscle,  in  augmenting 
the  tension  of  the  membrane,  and  thus  enabling  it  to  vibrate  in  reciprocation  to 
sounds  having  a  great  variety  of  fundamental  notes.  It  appears  to  be  antagonized 
by  the  stapedius,  the  contraction  of  which  seems  to  diminish  the  tension  of  the 
membrana  tympani,  and  to  take-off  pressure  from  the  fluid  of  the  labyrinth. 
These  two  muscles  conjointly  may  be  considered  to  regulate  the  transmission  of 
sonorous  undulations  to  the  fluid  of  the  internal  sac,  preventing  it  from  being  too 
violently  affected  by  loud  sounds,  in  the  same  manner  that  the  iris  regulates  the 
admission  of  light  to  the  eye  (§  757) ;  and  the  analogy  extends  also  to  their  ner- 
vous supply,  the  stapedius  being  excited  to  action  by  a  branch  of  the  Facial, 
whilst  the  tensor  tympani  receives  its  nerves  from  the  Otic  ganglion  (§  825). * 
They  are  probably  put  into  conjoint  action  when  we  are  listening  for  faint  sounds, 
so  as  to  bring  the  tympanum  into  the  state  of  tension  best  adapted  to  reciprocate 
them  ;  whilst  by  a  like  preparation,  the  concussive  effects  of  a  loud  sound  that  is 
anticipated,  are  more  effectually  moderated  than  when  it  strikes  the  ear  without 
warning.  It  is  probably  owing  to  an  imperfect  action  of  these  muscles,  that  some 
persons  are  deaf  to  grave  sounds,  whilst  they  readily  hear  the  more  acute. 

782.  The  uses  of  the  Tympanic  Cavity  are  very  obvious.     One  of  its  purposes 

is  to  render  the  vibrations  of  the  membrane  quite 
free ;  and  the  other,  to  isolate  the  chain  of  bones, 
in  such  a  manner  as  to  prevent  their  vibrations 
from  being  weakened  by  diffusion  through  the  sur- 
rounding solid  parts.  As  to  the  objects  of  the 
Eustachian  Tube,,  opinions  have  been  much  divided. 
Many  of  these  opinions,  however, — such  as  the  one 
most  commonly  entertained,  that  it  serves  the  same 
purpose  as  the  hole  in  an  ordinary  drum,  removing 
an  impediment  to  the  free  vibration  of  the  mem- 
brane, that  would  be  offered  by  the  complete  in- 
closure  of  the  air  within, — are  at  once  negatived  by 
the  fact,  which  seems  to  have  been  demonstrated 
by  Mr.  Toynbee,  that  the  guttural  orifice  of  the  tube 
is  usually  closed,  being  only  opened  during  the  act 
of  swallowing.2  The  principal  object  of  the  Eusta- 
chian tube  (which  is  always  found  where  there  is  a 
tympanic  cavity)  seems  to  be,  the  maintenance  of 
equilibrium  between  the  air  within  the  tympanum 
and  the  external  air;  so  as  to  prevent  inordinate 
tension  of  the  membrana  tympani,  which  would  be 
produced  by  too  great  or  too  little  pressure  on  either 
side,  and  the  effect  of  which  would  be  imperfection 
of  hearing.  It  also  has  the  office  of  convey  in  g-away 
mucus  secreted  in  the  cavity  of  the  tympanum,  by 
means  of  the  vibratile  cilia  which  clothe  its  lining 
membrane ;  and  the  deafness  consequent  on  occlu- 
sion of  this  tube,  is  in  part  explicable  by  the  ac- 
cumulation  which  then  takes-place  in  the  cavity. 

783.  From  what  has  been  stated,  it  is  evident  that  sonorous  undulations  in  the 
vicinity,  the  membrane  will  immediately  be  set  in  vibration,  not  as  a  whole  (unless  its  fun- 
damental note  be  in  unison  with  that  sounded),  but  in  different  segments,  of  which  every 
one  reciprocates  the  sound ;  from  the  vibrating  parts,  the  sand  will  be  violently  thrown, 
off ;  but  it  will  settle  on  the  intermediate  lines  of  rest,  which  are  known  as  the  nodal  lines, 
forming  a  variety  of  curious  figures. 

1  See  Mr.  C.  Brooke  in  "Lancet."  1843,  p.  380;  and  Mr.  Toynbee  in  "Brit,  and  For. 
Med.-Chir.  Rev.,"  vol.  xi.  p.  235. 

a  Loc.  cit.,  and  "  Proceedings  of  Royal  Society,"  1852. 


Ossicles  of  the  left  ear  articu- 
lated, and  seen  from  the  outside 
and  below,  m.  Head  of  the  mal- 
leus, below  which  is  the  constric- 
tion, or  neck.  g.  Processus  gra- 
cilis,  or  long  process,  at  the  root 
of  which  is  the  short  process,  h. 
Manubrium,  or  handle,  ec.  Short 
crus ;  and  Ic,  long  crus  of  the 
incus.  The  body  of  this  bone  is 
seen  articulating  with  the  malleus, 
and  its  long  crus,  through  the 
medium  of  the  orbicular  process, 
here  partly  concealed,  a,  with  the 
stapes,  s.  Base  of  the  stapes. 
Magnified  three  diameters.  From 
Arnold.] 


SENSE   OF   HEARING:  — •  j  s  E  s  OF   LABYRINTH.       ^;)7 

air  will  be  propagated  to  the  fluid  contained  in  the  labyrinth, — through  ihe 
tympanum,  the  chain  of  bones,  and  the  membrane  of  the  fencstra  ovalis  to 
which  the  stapes  is  attached — without  any  loss,  but  rather  an  increase  of  intensity. 
Why  water  should  be  chosen,  as  the  medium  through  which  the  impression  is  to 
be  made  upon  the  nerve,  it  is  impossible  for  us  to  say  with  anything  like  certainty, 
in  our  present  state  of  ignorance  as  to  the  physical  character  of  that  impres- 
sion. But  the  problem  being  to  communicate  to  water  the  sonorous  undulations 
of  air,  the  experimental  results  already  detailed  satisfactorily  prove  that — whilst 
this  may  be  accomplished;  in  a  degree  sufficient  for  the  wants  of  the  inferior 


[FIG.  179. 


Diagram  of  the  inner  wall  of  the  tympanum  after  maceration,  the  outer  wall  and  issicles 
being  removed,  a.  Fenestra  ovalis.  b.  Fenestra  rotunda,  c.  Promontory,  d.  Pyramid  with 
the  orifice  at  its  apex.  e.  Projection  of  the  aqueductus  Fallopii.  f.  Some  of  the  mastoid  cells 
communicating  with  the  tympanum,  g.  Processus  cochleariformis,  bounding  i,  the  canal  for 
the  tensor  tympani  muscle  :  the  anterior  pyramid  is  broken  off,  if  it  existed,  h.  Commence- 
ment of  the  Eustachian  tube.  j.  Jugular  fossa,  immediately  below  the  tympanum.  &>  k. 
Carotid  canal,  with  the  artery  in  outline,  to  show  its  course  in  relation  to  the  tympanum  and 
Eustachian  tube.  L  Portio  dura  of  the  seventh  pair  of  nerves,  as  it  would  be  seen  in  the 
terminal  part  of  the  aqueduct  of  Fallopius.  m.  Chorda  tympani,  leaving  the  portio  dura  and 
entering  a  short  canal,  which  opens  in  the  tympanum,  at  the  base  of  the  pyramid,  n.  Grooves 
for  the  tympanic  plexus.] 

animals,  by  the  simple  interposition  of  a  tense  membrane  between  the  air  and  tLa 
fluid, — the  tympanic  apparatus  of  the  higher  classes  is  most  admirably  adapted 
for  this  purpose. — The  fenestra  ovalis  is  not,  however,  the  only  channel  of  com- 
munication between  the  tympanum  and  the  labyrinth;  for  there  is  in  most 
animals,  a  second  aperture,  the  fenestra  rotunda,  leading  into  the  cochlea,  and 
simply  covered  with  a  membrane.  It  is  generally  supposed  that,  the  labyrinth 
being  filled  with  a  nearly  incompressible  fluid,  this  second  aperture  is  necessary 
to  allow  the  free  vibration  of  that  fluid ;  the  membrane  of  the  fenestra  rotunda 
being  made  to  bulge-out,  as  that  of  the  fenestra  ovalis  is  pushed-in.  It  may  be1 
easily  shown  by  experiment,  however,  as  well  as  by  reference  to  comparative 
anatomy,  that  no  such  contrivance  is  necessary;  for  sonorous  undulations  may  be 
excited  in  a  non-elastic  fluid,  completely  inclosed  within  solid  walls  at  every  part 
except  where  these  are  replaced  by  the  membrane  through  which  the  vibrations 
are  propagated;  and  this  is  precisely  the  condition  not  only  of  Invertebrated 
animals,  but  even  of  Frogs;  in  which  last  a  tympanic  apparatus  exists,  without 
a  second  orifice  into  the  labyrinth  Moreover  it  is  certain,  that  the  vibrations  of 


698         OF   THE   ORGANS   OF   THE    SENSES,    AND   THEIR   FUNCTIONS. 

the  air  in  the  cavity  of  the  tympanum,  must  of  themselves  act  upon  the  mem- 
brane of  the  fenestra  rotunda;  and  this  is  perhaps  the  most  direct  manner  in 
which  the  fluid  in  the  cochlea  will  be  affected,  although  it  will  ultimately  be 
thrown  into  much  more  powerful  action,  by  the  transmission  of  vibrations  from 
the  vestibule.  For  it  has  been  satisfactorily  determined  by  experiment  (xil.), 
that  vibrations  are  transmitted  with  very  much  greater  intensity  to  water,  when 
a  tense  membrane,  and  a  chain  of  insulated  solid  bodies  capable  of  free  movement, 
are  successively  the  conducting  media,  than  when  the  media  of  communication 
between  the  vibrating  air  and  the  water  are  the  same  tense  membrane,  air,  and  a 
second  membrane : — or,  to  apply  this  fact  to  the  organ  of  hearing,  the  same 
vibrations  of  the  air  act  upon  the  fluid  of  the  labyrinth  with  much  greater  inten- 
sity, through  the  medium  of  the  chain  of  auditory  bones  and  the  fenestra  ovalis, 
than  through  the  medium  of  the  air  of  the  tympanum  and  the  membrane  closing 
the  fenestra  rotunda.  The  fenestra  rotunda  is  not  to  be  considered  as  having  any 
peculiar  relation  with  the  cochlea;  since,  in  the  Turtle  tribe,  the  former  exists 
without  the  latter. 

784.  It  is  obviously  in  the  Labyrinth  as  a  whole,  that  the  sonorous  vibrations 
are  brought  to  bear  upon  the  Auditory  nerve  spread-out  to  receive,  them.  In 
regard  to  the  special  functions  of  particular  parts  of  the  labyrinth,  however, 
no  certainty  can  be  said  to  exist.  The  membrane  which  lines  its  cavities  not 
only  contains  a  liquid  (the  endo-lympTi),  but  is  also  separated  from  the  osseous 
wall  by  another  collection  of  liquid,  the  peri-lymph  ;  so  that  it  is  suspended,  as 
it  were,  in  a  liquid  which  bathes  both  its  surfaces.  In  the  cavity  of  the  Vestibule, 


[FIG.  180.  [FIG.  181. 


Fig.  180.— Interior  of  the  osseous  labyrinth.  V.  Vestibule,  a,  v.  Aqueduct  of  the  ves- 
tibule, o.  Fovea  semi-elliptica.  r.  Fovea  hemispherica.  S.  Semi  circularcanals.  «.  Superior. 
p.  Posterior,  i.  Inferior,  a  a  a,  The  ampullar  extremity  of  each.  C.  Cochlea,  a  c.  Aqueduct  of 
the  cochlea,  sv.  Osseous  zone  of  the  lamina  spiralis,  above  which  is  the  scala  vestibuli,  commu- 
nicating with  the  vestibule,  st.  Scala  tympani  below  the  spiral  lamina.  From  Soemmerring.] 

Fig.  181.— Membranous  labyrinth  of  the  left  side,  with  its  nerves  and  otoliths  :— su.  Superior 
Semicircular  canal,  with  the  ampulla  and  its  nerve  at  one  end,  and  the  other  end  joined  by 
p,  the  posterior  canal,  to  form  the  tabulua  communis.  i.  Inferior,  or  horizontal  canal,  with  the 
ampulla  and  its  nerve  at  one  end,  and  the  other  entering  the  utriculus  separately,  c. 
Powdery  otolith  seen  through  the  translucent  wall  of  the  common  sinus  or  utriculus,  with 
the  nerves  distributed  to  it.  «.  Powdery  otolith  of  the  sacculus  seen  with  its  nerve,  in  a 
similar  way.  n.  Cochlear  division  of  the  auditory  nerve  cut  off  where  it  enters  the  cochlea. 
d.  Portio  dura  of  the  seventh  pair  leaving  the  auditory  nerve,  or  portio  moUie,  to  enter  the 
aqueduct  of  Fallopius.  Magnified.  From  Brescbet.l 


SENSE   OF  HEARING:  —  USES  or  LABYRINTH.        699 

which  is  subdivided  by  a  membranous  partition  into  two,  are  found  small  masses 
of  concretionary  particles,  collectively  named  otoconia  or  ear-powder ;  these  are 
obviously  the  rudiments  of  the  otoliths,  or  ear-stones,  whose  presence,  in  animals 
with  a  less  perfect  auditory  apparatus,  seems  needful  to  intensify  the  undulations. 
It  is  commonly  supposed  that  the  Semicircular  Canals  have  for  their  peculiar 
function,  to  receive  the  impressions  by  which  we  distinguish  the  direction  of 
sounds  ;  and  it  is  certainly  a  powerful  argument  in  support  of  this  view,  that, 
in  almost  every  instance  in  which  these  parts  exist  at  all,  they  hold  the  same 
relative  positions  as  in  Man,  their  three  planes  being  nearly  at  right  angles  to 
one  another.  The  idea,  however,  must  be  regarded  as  a  mere  speculation,  the 
value  of  which  cannot  be  decided  without  an  increased  knowledge  of  the  laws 
according  to  which  sonorous  vibrations  are  transmitted ;  but  it  receives  a  certain 
degree  of  confirmation  from  the  curious  movements  witnessed  by  M.  Flourens 
after  section  of  one  or  other  of  these  canals  .(§  531). — Regarding  the  special 
function  of  the  Cochlea,  there  is  precisely  the  same  uncertainty.  This  part  of 
the  organ  is  peculiar  in  one  respect,  that  the  expansion  of  the  auditory  nerve  is 
here  spread-out  (within  the  lamina  spiralis)  in  closer  proximity  with  the  bone 
itself,  than  it  is  in  any  other  part  of  the  labyrinth ;  and  moreover  the  peri-lymph 
is  here  deficient,  so  that  the  membranous  lining  of  the  cochlea  is  in  absolute  con- 
tact with  its  osseous  wall.  It  is  not  easy  to  see,  however,  what  can  be  the  pecu- 
liar object  of  this  disposition  in  regard  to  the  function  of  hearing.  It  has  been 

[FiG.  182. 


Cochlea  of  a  new-born  infant,  opened  on  the  side  towards  the  apex  of  the  petrous  bone. 
It  shows  the  general  arrangement  of  the  two  scalae,  the  lamina  spiralis,  and  the  distribution 
of  the  cochlear  nerve.  At  the  apex  is  seen  the  modiolus  expanding  into  the  cupola,  where 
the  spiral  canal  terminates  in  a  cul-de-sac.  The  helicotrema  is  not  visible  in  this  view. 
From  Arnold.] 

surmised  by  M.  Duges,  that  by  the  Cochlea  we  are  especially  enabled  to  estimate 
the  pitch  of  sounds,  particularly  of  the  voice ;  and  he  adduces  in  support  of  this 
idea,  the  fact,  that  the  development  of  the  cochlea  follows  a  very  similar  propor- 
tion with  the  compass  of  the  voice.  This  is  much  the  greatest  in  the  Mammalia ; 
less  in  Birds ;  and  in  Reptiles  which  have  little  true  vocal  power,  the  cochlea  is 
reduced  to  its  lowest  form,  disappearing  entirely  in  the  Amphibia.  That  there 
should  be  an  acoustic  relation  between  the  voice  and  ear  of  each  species  of  ani 
mal,  cannot  be  regarded  as  improbable  ;  but  the  speculation  of  M.  Duges  can 
at  present  only  be  received  as  a  stimulus  to  further  inquiry.1 

1  [Prof.  Jackson,  of  the  University  of  Pennsylvania,  in  his  public  lectures  for  the  las* 
three  years,  has  assigned  a  different  function  to  the  semi-circular  canals  and  cochlea,  which 
appears  to  be  more  in  accordance  with  facts  than  any  that  has  hitherto  been  produced.  Ac- 
cording to  him  "  the  semi-circular  canals  have  no  direct  agency  in  the  production  of  sound  or 
hearing.  They  contain  no  nervous  structure :  no  portion  of  the  acoustic  nerve  reaches 
them.  They  are  small  appendages  to  the  vestibule,  opening  into  it  and  the  ampullae.  The 
membranous  canals,  like  the  membranous  vestibule,  are  floated  in  a  fluid,  the  peri-lymph, 
and  are  filled  with  a  similar  fluid,  the  endo-lymph.  The  membranous  structure  consti 
tutes  the  essential  solid  portion  of  the  organ  of  hearing.  It  is  nowhere  in  direct  contact 


700         OF   THE    ORGANS    OF   THE    SENSES    AND    THEIR    FUNCTIONS. 

785.  We  have  now  to  consider  the  functions  of  the  accessory  parts, — the  Ex- 
ternal Ear,  and  the  Meatus.  The  Cartilage  of  the  external  ear  may  propagate 
sonorous  vibration  in  two  ways;  by  reflection,  and  by  conduction.  In  reflection, 

with  the  osseous  walls  of  the  corresponding  cavities  excavated  in  the  temporal  bone.  The 
peri-lymph  is  interposed  between  the  membranous  vestibule,  the  semi-circular  canals,  and 
the  surrounding  osseous  walls.  In  the  Petromyzon,  this  membranous  structure  (vestibule 
and  semi-circular  canals)  is  contained  in  a  common  cavity,  unenclosed  in  corresponding 
excavations  in  bone  substance.1  As  Miiller  observes,  this  is  "a  fact  of  great  physiological 
importance."  It  proves  the  membranous  portion  of  the  apparatus  of  hearing  and  its  fluid 
to  be  independent  of  the  bony  structure  in  the  excitation  of  the  sense  of  sound  or  hearing. 

**  The  semi-circular  canals  are  evidently  intended  to  perfect  the  sense  of  hearing  or  sound, 
as  executed  in  its  most  complete  manifestations,  in  the  higher  development  of  this  appa- 
ratus of  sense  in  man  and  the  superior  animals. 

"  The  hypothesis  of  Scarpa  has  been  adopted  as  the  most  plausible  in  this  point  of  view. 
He  supposed  the  semi-circular  canals  to  be  intended  to  increase  the  intensity  of  the  sonorous 
impressions  on  the  acoustic  nerve,  and  thus  to  make  hearing  more  distinct.  They  effect 
this  operation  bv  receiving  and  collecting  the  vibrations  of  the  solid  parietes  of  the  cra- 
nium transmitted  to  the  lymph-fluid,  and  through  it  to  the  nervous  expansion  of  the  acous- 
tic nerve. 

"  This  hypothesis  cannot  be  entertained.  In  the  first  place,  it  is  very  doubtful  whether 
the  aerial  vibrations,  in  ordinary  hearing,  can  or  do  communicate  vibrations  to  the  hnrd 
parts  of  the  cranium.  When  a  light  carriage  passes  rapidly  over  the  rough  pavement 
with  sharp,  rattling  noise,  if  the  ears  be  completely  closed,  not  a  sound  is  heard ;  nor  is  a 
single  note  of  a  large  orchestra  to  be  distinguished  when  the  ears  are  pressed  with  the 
fingers.  When  sound  is  attended  with  concussion,  a  noise  may  then  be  distinguished,  but 
this  differs  from  the  ordinary  sense  of  hearing.  If  vibrations  are  excited  in  the  solid 
parts  of  the  cranium  by  sonorous  vibrations  of  the  air.  they  are  obviously  too  feeble  to 
make  an  impression  on  the  nerves  of  sense,  and  incapable  of  reinforcing  the  vibrations 
transmitted  through  the  stapes. 

"  In  the  second  place,  vibrations,  if  excited  in  the  lymph-fluid  of  the  semi-circular  canals, 
would  move  in  a  direction  the  reverse  of  the  molecular  vibrations  of  the  lymph-fluid  of  the 
vestibule  and  ampullae,  the  real  excitors  of  the  sense  of  hearing  or  sound.  These  vibra- 
tions are  transmitted  through  the  fenestra  ovalis  by  the  stapes,  and  radiate  from  that 
point  in  expanding  waves  through  the  vestibular  lymph-fluid  into  the  ampullae  and  semi- 
circular canals.  Vibrations  proceeding  from  the  solid  walls  of  the  semi-circular  canals, 
to  reach  the  nerve-expansions,  would  come  in  conflict  with  those  proceeding  from  the 
stapes,  and  either  interference,  and  consequent  suppression  and  silence  would  'ensue,  or 
the  effect  of  an  echo,  or  noise,  or  simple  sound  be  the  result.  The  hypothesis  of  Scarpa, 
it  appears  to  me,  cannot  be  sustained,  though  ably  advocated  by  Miiller. 

"  The  hypothesis  that  assigns  to  the  semi-circular  canals  the  perception  of  the  direction 
of  sound  does  not  merit  an  investigation.  The  notion  of  the  direction  of  sound,  like  that 
of  distance,  is  a  mental  action ;  a  conclusion  to  which  the  mind  arrives,  from  certain  phe- 
nomena or  facts  acquired  by  experience. 

"As  to  the  manner  in  which  the  semi-circular  canals  perfect  the  sense  of  hearing,  my 
conclusion  is  the  opposite  to  that  of  Scarpa.  Instead  of  increasing  the  sonorous  un- 
dulations or  vibrations  of  the  lymph  of  the  vestibule,  the  immediate  excitants  of  the  sense 
of  hearing,  they  serve  to  suppress  them.  They  arrest  the  waves  of  reflexion  which 
would  necessarily  occur  in  a  simple  cavity,  wholly  limited  by  plane  surfaces,  as  the  vesti- 
bule would  be  without  these  appendages.  Such  is  the  rudimentary  vestibule  or  internal  ear  of 
the  invertebrata.  The  consequence  of  reflected  undulating  vibrations,  maintained  in  the 
labyrinthic  fluid,  would  be  the  production  of  mere  sound  or  noise  of  different  intensities. 
The  perception  of  the  immense  number  of  fine  and  delicate  tones,  and  other  qualities  of 
sound  of  which  the  ear  has  cognizance,  would  be  utterly  impossible  in  the  confusion  of 
sonorous  vibrations  in  the  fluid  of  the  labyrinth  continuously  reflected  to  and  fro,  unless 
some  provision  is  made  for  their  suppression.  The  molecules  of  a  fluid  contained  in  a  closed 
vessel  continue  in  undulatory  vibration  until  the  impetus  exciting  their  motion  is  expended 
or  suppressed.  The  semi-circular  canals  accomplish  this  purpose.  They  are,  in  the  appa- 
ratus of  hearing,  what  the  pigmentum  nigrum  of  the  choroid  coat  is  in  that  of  vision. 

"  The  two  senses  and  their  apparatus  are  homologous.  The  essential  phenomena  and  laws 
of  each  are  identical.  The  knowledge  of  those  of  the  one  sense  demonstrates  those  of  the 
other.  The  conditions  of  perfect  vision  and  perfect  hearing  are  the  same.  They  are,  1st, 
The  existence  of  separate,  independent,  sensitive  spaces  or  sections  of  the  retina  for  dis- 
tinct images  and  perceptions  of  visual  impressions.  Volkmann  estimates  these  to  be 


MuJler's  Physiology,"  Baly's  translation,  vol  ii.  p.  1288. 


SENSE   OF  HEARING:  —  USE  OF  LABYRINTH.         701 

the  concha  is  the  most  important  part,  since  it  directs  the  reflected  undulations 
towards  the  tragus,  whence  they  are  thrown  into  the  auditory  passage.  The 
other  inequalities  of  the  external  ear  cannot  promote  hearing  by  reflection  •  and 

0«-n>.0005  ;i  and  others  at  -gws^os  °f  an  inch.3  2d,  A  single  distinct  impression  made  by 
the  molecular  vibration  of  the  Ether — the  excitor  of  the  sense  of  sight. 

"  The  above  conditions  are  obtained,  a,  by  the  special  anatomical  arrangement  of  the  re- 
tina :  b,  by  the  refracting  apparatus  of  the  globe  of  the  eye  that  concentrates  the  undula- 
tory  rays  of  the  Ether  proceeding  from  every  point  of  a  visual  object  on  the  distinct  sensi- 
tive points  or  spaces  of  the  retina:  c,  by  the  suppression  of  the  undulatory  vibrations  im- 
mediately they  have  excited  an  impression  in  the  retina,  by  the  black  pigment  of  the  cho- 
roid  coat.  Their  reflection  from  the  exterior  surface  of  the  sclerotic  coat,  and  reiterated 
excitement  of  the  retinal  surface,  is  in  this  way  prevented.  In  Albinos  the  pigment  of  the 
choroid  is  either  deficient  or  absent,  and  the  consequence  is  indistinct  vision  in  day-light, 
from  the  general  excitement  of  the  retina  by  the  reflected  undulations  of  the  Ether  occu- 
pying the  globe  of  the  eye. 

"  The  same  conditions  are  obtained  in  hearing,  1st.  by  the  auditive  nerve  being  decom- 
posed into  its  separate  filaments  and  ganglionic  vesicles,  amounting  to  some  thousands, 
and  spread  out  in  a  manner  to  receive  single,  individual  impressions,  in  the  membranous 
vestibule,  ampulla?,  and  on  the  lamina  spiralis  of  the  cochlea.  2nd,  By  the  molecular  un- 
dulations or  vibrations  excited  in  the  fluids — peri-  and  endo-lymph — by  the  sonorous  undu- 
lations communicated  by  the  stapes,  occupying  the  fenestra  ovalis.  From  this  point  they 
radiate  in  expanding  waves  of  undulations,  strike  on  and  pass  through  the  membranous 
vestibule  and  ampullae,  on  which  the  filaments  of  the  vestibular  branch  of  the  auditive 
nerve  are  arranged,  producing  a  single,  distinct  impression,  reinforced  by  the  resonance 
of  the  superimposed  otoconige,  and  exciting  a  single  and  distinct  impulse,  and  perception 
of  sound.  These  bodies  act  like  the  sounding-board  of  the  piano.  The  sonorous  vibra- 
tion having  thus  completed  its  office,  the  specific  excitation  of  the  sense  of  hearing,  must, 
like  that  of  the  visual  vibration,  cease  or  be  suppressed.  This  occurs  in  part  in  the  am- 
pulloe,  but  mostly  in  the  semi-circular  canals. 

"  The  vibrations  of  the  endo-lymph  reaching  the  ampullae  are  partially  broken  and  weak- 
ened at  their  openings ;  those  entering  the  ampullae  again  expand,  losing  thereby  their 
impetus,  and  either  die  away  against  the  membranous  walls,  or  come  in  conflict  with  the  vi- 
brations of  the  peri-lyrnph  on  their  exterior.  The  two  can  scarcely  be  in  perfect  consonance 
of  expansion  or  condensation,  and  interference  ensues  by  which  they  are  suppressed.  In  this 
mode  all  the  feebler  vibrations  are  terminated.  Those  of  greater  force  enter  simultaneously 
the  two  opposite  openings  of  the  semi-circular  canals.  The  orifices  and  the  commencement 
of  each  canal  differ  as  to  size  and  form,  and  consequently  each  entering  wave  of  undula- 
latory  vibrations  is  modified,  thus  losing  their  consonance  of  expansion,  and  when  they 
meet  interference  and  suppression  result.  Reflexion  of  sonorous  vibrations  is  completely 
provided  against. 

"  Parallel  conditions  exist  in  the  cochlea.  Its  two  canals — the  superior-scala  vestibuli, 
— and  the  inferior-scala  tympani, — are  filled  with  lymph-fluid  continuous  and  identical 
with  that  of  the  vestibule.  The  first,  the  scala  vestibuli,  according  to  the  latest  investiga- 
tions of  Kolliker3,  is  the  principal  seat  of  hearing.  On  its  lamina  spiralis  is  expanded  a  sen- 
tient, nervous  structure,  the  recipient  of  the  sonorous  vibrations  excitative  of  the  sense  of 
hearing.  It  is  the  homotype  of  the  retina  of  the  eye.  The  scala  tympani  furnishes  space 
for  spreading  out  the  filaments  of  the  nerve,  but  the  terminal  extremities  pass  through  the 
membranous  spiral  lamina,  to  be  incorporated  with  the  sentient  organ  of  hearing  in  the 
superior  canal  or  scala  vestibuli.  The  filaments  of  the  inferior  canal  or  scala  tympani  are 
mere  conductors  of  the  nervous  excitement  of  the  auditive  sentient  membrane.  The  scala 
tympani,  similar  to  the  semi-circular  canals,  has  no  direct  connexion  with  the  production 
of  hearing.  It  is  the  homotype  of  the  semi-circular  canals  and  performs  the  same  office. 

"  The  sonorous  vibrations  starting  from  the  stapes  and  fenestra  ovalis,  rushing  into  the  ad- 
jacent-opening of  the  scala  vestibuli,  excite,  by  their  impulse,  the  auditory  membrane  or 
retina,  spread  over  its  lamina  spiralis,  and  reach  its  termination  where  it  opens  into  the  scala 
tympani.  Feeble  vibrations  may  subside  spontaneously  by  exhaustion  from  their  extension 
The  stronger  pass  on  into  the  scala  tympani,  where  they  fade  away,  or  are  suppressed  by 
the  interference  of  vibrations  entering  the  inferior  canal  by  the  fenestra  rotunda  from  th'e 
tympanum.  The  condition  for  perfect  hearing,  for  the  distinct  perception  and  appreciation 
of  the  finest  tones  and  notes,  so  that  each  vibration  shall  make  but  une,  single,  distinct  im- 
pression, and  then  be  suppressed,  is  thus  amply  fulfilled. 

"  Analogous  provisions  are  perceived  to  exist  in  the  tympanum,  to  preserve  in  that  cavity 

1  "Annual  Report  of  the  Progress  of  Chemistry  and  Allied  Sciences,"  by  Liebig  anri 
Kopp,  vol.  iii.  p.  98. 

a  "Lardner's  Handbook  of  Optics,"  p.  155. 
8  "  Human  Microscopical  Anatomy."     Da-Costa  translation.     Note,  p.  175. 


702      OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

the  purpose  of  the  extension  of  its  cartilage  is  evidently  to  receive  the  sonorous 
vibrations  from  the  air,  and  to  conduct  them  to  its  source  of  attachment.  In 
this  point  of  view,  the  inequalities  become  of  importance  ;  for  those  elevations 
and  depressions  upon  which  the  undulations  fall  perpendicularly,  will  be  affected 
by  them  in  the  most  intense  degree;  and  in  consequence  of  the  varied  form  and 
position  of  these  inequalities,  sonorous  undulations  in  whatever  direction  they 
may  come,  must  fall  advantageously  upon  some  of  them. — The  functions  of  thfi 
Meatus  appear  to  be  threefold.  The  sonorous  undulations  entering  from  the 
atmosphere  are  propagated  directly,  without  dispersion,  to  the  mernbrana  tym- 
pani  :  the  sonorous  undulations  received  on  the  external  ear,  are  conveyed  along 
the  walls  of  the  meatus  to  the  membrana  tympani;  whilst  the  air  which  it  con- 
tains, like  all  insulated  masses  of  air,  increases  the  intensity  of  sounds  by  reson- 
ance. That,  in  ordinary  hearing,  the  direct  transmission  of  atmospheric  vibra- 
tions to  the  membrana  tympani,  is  the  principal  means  of  exciting  the  reciprocal 
vibrations  of  the  latter,  is  sufficiently  evident;  the  undulations  which  directly 
enter  the  passage,  will  pass  straight-on  to  the  membrane  ;  while  those  that  enter 
obliquely  will  be  reflected  from  side  to  side,  and  at  last  will  fall  obliquely  on  the 
membrane,  thus  perhaps  contributing  to  the  notion  of  direction.  The  power  of 
the  lining  of  the  meatus  to  conduct  sound  from  the  external  ear,  is  made  evident 
by  the  fact,  that,  when  both  cars  are  closely  stopped,  the  sound  of  a  pipe  having 
its  lower  extremity  covered  by  a  membrane,  is  heard  more  distinctly  when  it  is 
applied  to  the  cartilage  of  the  external  ear  itself,  than  when  it  is  placed  in  con- 
tact with  the  surface  of  the  head.  The  resonant  action  of  the  air  in  the  tube  is 
easily  demonstrated,  by  lengthening  the  passage  by  the  introduction  of  another 

perfect  wave-systems  of  undulations,  indispensable  to  the  perfection  of  the  sense  of  hear- 
ing. Vibrations  existing  in  air  contained  in  a  cavity  with  plane  walls,  would  continue  to 
be  reflected  from  side  to  side,  producing  confused  sounds  or  noise.  The  air  in  the  tym- 
panum is  thrown  into  vibrations  by  impulses  of  the  membrana  tympani.  They  are  com- 
municated pure  and  in  perfect  accord  to  the  membrane  of  the  fenestra  rotunda.  This 
curious  and  beautiful  result  is  effected  in  the  following  manner:  on  one  side  the  tympanum 
communicates  by  numerous  openings  with  the  mastoid  cells  communicating  with  one  an- 
other. All  the  vibrations  impinging  on  this  side  are  suppressed  in  the  mastoid  cells.  Those 
that  reach  the  opposite  side  are  swallowed  up  and  lost  in  the  Eustachian  tube.  All  resonance 
and  reflexion  of  vibrations  are  suppressed,  and  the  wave-systems  of  sonorous  vibrations 
traverse  the  tympanum  undisturbed,  enter  with  augmented  force  the  lymph-fluid  of  the 
scala  tympani,  and  meet  the  corresponding  undulations  coming  from  the  scala  vestibuli, 
from  which  both  systems  are  suppressed  by  interference. 

"In  the  'Annual  Report'  by  Justus  Liebig  and  H.  Kopp,  vol.  iii.  p.  53,  is  the  follow- 
ing observation.  '  It  is  certain  that  the  ear  is  capable  of  receiving  and  distinguishing 
many  notes,  the  vibrations  of  which  reach  it  simultaneously.  As  the  atmospheric  parti- 
cles which  convey  the  various  wave-systems  to  the  ear  can  never  receive  from  them  more 
than  one  resulting  motion,  it  follows  necessarily  that  the  ear  possesses  the  power  of  dis- 
tinguishing in  this  resulting  motion,  the  periods  of  the  component  wave-trains.  For  the 
present  we  are,  however,  unable  to  explain  upon  what  this  power  depends.' 

"  The  preceding  theory  furnishes  an  explanation  of  the  above  problem  considered  as  inex- 
plicable by  Liebig  and  Kopp,  in  1852.  It  demonstrates  the  manner  in  which  the  wave- 
systems  of  sonorous  vibrations  pass  through  the  fluid  of  the  labyrinth  undisturbed,  pre- 
serving their  relations  to  each  other  and  their  special  qualities  of  sound.  Each  separate 
vibration  of  the  molecules  of  the  lymph-fluid  are  shown  to  produce  a  special,  distinct  im- 
pression on  the  nerve  structure,  and  excite  a  corresponding  perception  of  sound. 

"  The  small  space  through  which  the  vibrations  pass,  and  the  rapidity  of  their  movements 
in  fluids  cause  the  impressions  they  make  on  the  nervous  sentient  organ,  and  the  percep- 
tions they  excite,  to  appear  as  an  instantaneous  act.  The  mind  has  cognizance  of  them, 
however  diversified  they  may  be,  as  a  unity  of  sounds  simultaneously  instant  in  action: 
whence  it  forms  the  compound  idea  of  a  perfect  harmony. 

"  An  analagous  phenomenon  occurs  in  vision.  When  a  body  composed  of  different  forms 
and  colours  is  presented  to  the  eye,  as  a  bouquet  of  flowers,  a  landscape,  or  picture,  each 
different  form,  colour,  tint  and  shading,  are  perceived  blended,  but  perfect  and  distinct, 
forming  the  image  of  a  single  object.  Yet  thousands  of  Ether  vibrations  are  traversing 
the  eye,  and  are  exciting  each  a  separate,  distinct  impression,  without  confusion,  on  the 
retina,  and  as  many  distinct  and  separate  perceptions,  from  which  a  corresponding  com- 
pound idea  of  a  single  object  is  formed  by  the  mind." — Unpublished  Lecture. ED.] 


SENSE   OF  HEARING:  —  MUSICAL  TONES.  703 

tube  ;  the  intensity  of  external  sounds,  and  also  that  of  the  individual's  own 
voice,  as  heard  by  himself,  is  then  much  increased. 


.  183.  [Fio.  184. 


A  view  of  the  Left  Ear  in  its  natural  state :        An  anterior  view  of  the  External  Ear,  as  well 

1,  2,  the  origin  and  termination  of  the  helix;  as  of  the  Meatus  Auditorius,  Labyrinth,  <fcc.: 

3,  the  anti-helix;  4,  the  anti-tragus ;   5,  the  1,  the  opening  into  the  ear  at  the  bottom  of 

tragus;  6,  the  lobus  of  the  external  ear;  7,  the  concha;  2,  the  meatus  auditorius  externus 

points  to  the  scapha,  and  is  on  the  front  and  or  cartilaginous  canal ;  3,  the  membrana  tym- 

top  of  the  pinna;  8,  the  concha;  9,  the  meatus  pani  stretching  upon  its  ring;  4,  the  malleus  ; 

auditorius  externus.]  5,  the  stapes ;  6,  the  labyrinth.] 

786.  Many  facts  prove,   however,  that  the  fluid  of  the  Labyrinth  may  be 
thrown  into  vibration  in  other  ways  than  by  the  Tympanic  apparatus.     Thus  in 
Osseous  Fishes,  it  is  only  by  the  vibrations  transmitted  through  the  bones  of  the 
head,  that  hearing  can  take  place.     There  are  many  persons,  again,  who  can  dis- 
tinctly hear  sounds  which  are  thus  transmitted  to  them  ;  although,  through  some 
imperfection  of  the  tympanic  apparatus,  they  are  almost  insensible  to  those  which 
they  receive  in  the  ordinary  way.     It  is  evident,  where  this  is  the  case,  that  the 
nerve  must  be  in  a  state  fully  capable  of  functional  activity ;  and,  on  the  other 
hand,  where  sounds  cannot  thus  be  perceived,  there  will  be  good  reason  to  believe 
that  the  nerve  is  diseased. 

787.  A  single  impulse  communicated  to  the  Auditory  nerve,  in  any  of  the 
foregoing  modes,  seems  to  be  sufficient  to  excite  the  momentary  sensation  of 
sound  ;  but  most  frequently  a  series  of  such  impulses  is  concerned,  there  being 
but  few  sounds  which  do  not  partake,  in  a  greater  or  less  degree,  of  the  character 
of  a  tone.     Any  continuous  sound  or  tone  is  dependent  upon  a  succession  of 
impulses  j  and  its  acuteness  or  depth  is  governed   by  the  rapidity  with  which 
these  succeed  one  another.     It  is  not  difficult  to  ascertain  by  experiment,  what 
number  of  such  impulses  or  undulations  are  required,  to  give  every  tone  which 
the  ear  can  appreciate.     Thus,  if  a  circular  plate,  with  a  number  of  apertures  at 
regular  intervals,  be  made  to  revolve  over  the  top  of  a  pipe  through  which  air 
is  propelled,  a  succession  of  short  puffs  will  be  allowed  to  issue  from  this ;  and, 
if  the  revolution  be  sufficiently  rapid,  these  impulses  will  unite  into  a  definite 
tone.     In  the  same  manner,  if  a  spring  be  fixed  near  the  edge  of  a  revolving 
toothed  wheel,  in  such  a  manner  as  to  be  caught  by  every  tooth  as  it  passes,  a 
succession  of  clicks  will  be  heard;  and  these  too,  if  the  revolution  of  the  wheel 
be  sufficiently  rapid,  will  produce  a  tone.     The  number  of  apertures  in  the  plate 
which  pass  the  orifice  of  the  pipe  in  a  given  time,  or  the  number  of  teeth  which 
pass  the  spring,  being  known,  it  is  easy  to  see  that  this  must  be  the  number  of 
impulses  required  to  produce  the  given  tone.     Each  impulse  produces  a  double 


704      OF    THE    ORGANS    OF    THE    SENSES,    AND    THEIR    FUNCTIONS. 

vibration,  forwards  and  backwards  (as  seen  when  a  string  is  put  in  vibration,  by 
pulling  it  out  of  the  straight  line) ;  hence  the  number  of  single  vibrations  is 
always  double  that  of  the  impulses. — The  maximum  and  minimum  of  the  inter- 
vals of  successive  pulses,  still  appreciable  by  the  ear  as  determinate  sounds,  have 
also  been  determined  by  M.  Savart,  more  satisfactorily  and  more  accurately  than 
had  previously  been  done.  If  their  intensity  be  great,  sounds  are  still  audible 
which  result  from  the  succession  of  24,000  impulses  in  a  second ;  and  this,  pro- 
bably, is  not  the  extreme  limit  to  the  acuteness  of  sounds  perceptible  by  the  ear. 
From  some  observations  of  Dr.  Wollaston's,  it  seems  probable  that  the  ears  of 
different  individuals  are  differently  constituted  in  this  respect;  some  not  being 
able  to  hear  very  acute  tones  produced  by  Insects,  or  even  Birds,  which  are  dis- 
tinctly audible  to  others.  Again,  the  sound  resulting  from  16  impulses  per 
second,  is  not,  as  has  been  usually  supposed,  the  lowest  appreciable  note ;  on  the 
contrary,  M.  Savart  has  succeeded  in  rendering  tones  distinguishable,  which  are 
produced  by  only  7  or  8  impulses  in  a  second ;  and  continuous  sounds  of  a  still 
deeper  tone  could  be  heard,  if  the  individual  pulses  were  sufficiently  prolonged. 
In  regard,  however,  to  the  precise  time  during  which  a  sonorous  impression  re- 
mains upon  the  ear,  it  is  difficult  to  procure  exact  information,  since  it  departs 
more  gradually  than  do  visual  impressions  from  the  eye.  This  is  certain,  how- 
ever,— that  it  is  much  longer  than  the  interval  between  the  successive  pulses  in 
the  production  of  tones;  since  it  was  found  by  M.  Savart,  that  one  or  even 
several  teeth  might  be  removed  from  the  toothed  wheel,  without  a  perceptible 
break  in  its  sound, — showing  that,  when  the  tone  was  once  established,  the  im- 
pression of  it  remained  during  an  intermission  of  some  length. 

788.  The  power  of  distinguishing  the  direction  of  sounds  appears  to  be,  in 
Man  at  least,  for  the  most  part  acquired  by  habit ;  for  it  is  some  time  before  the 
infant  seems  to  know  anything  of  the  direction  of  noises  which  attract  his  atten- 
tion. Our  judgment  as  to  this  point  is  probably  assisted,  in  most  cases,  by  a 
difference  in  the  intensity  of  the  sensations  received  through  the  two  ears  re- 
spectively; but  since  we  have  a  certain  power  of  appreciating  direction  when  one 
ear  alone  is  used,  this  power  must  depend  upon  an  exercise  of  perceptive  dis- 
crimination (which  is  probably  acquired,  rather  than  intuitive),  in  regard  to  the 
impressions  which  we  receive  through  its  means;  and  it  has  been  already  men- 
tioned, that  the  Semicircular  canals  (§  784)  appear  to  furnish  the  instrumentality 
by  which  our  minds  are  enabled  to  take  cognizance  of  such  differences. — The 
idea  of  the  distance  of  the  sonorous  body  is  another  acquired  perception,  depend- 
ing principally  upon  the  loudness  or  faintness  of  the  sound,  when  we  have  no 
other  indications  to  guide  us.  In  this  respect  there  is  a  great  similarity  between 
the  perception  of  the  distance  of  an  object,  through  the  Eye  by  its  size,  and 
through  the  Ear  by  the  intensity  of  its  sound.  When  we  are  acquainted  with 
the  usual  intensity  of  its  sound,  we  can  judge  of  its  distance ;  and  vice  versa, 
when  we  know  its  distance,  we  can  at  once  form  an  idea  of  its  real  strength  of 
tone  from  that  with  which  our  ears  are  impressed.  In  this  manner,  the  mind 
may  be  affected  with  corresponding  deceptions  through  both  senses  :  for  as,  in 
the  Phantasmagoria,  the  figure  being  gradually  diminished  whilst  its  distance 
remains  the  same,  it  appears  to  the  spectators  to  recede  (the  illusion  being  more 
complete  if  its  brightness  be  at  the  sa-me  time  diminished) ;  so  the  effect  of  a  distant 
full  military  band  gradually  approaching,  may  be  alike  given  by  a  corresponding 
crescendo  of  concealed  instruments.  It  is  upon  the  complete  imitation  of  the 
conditions  which  govern  our  ideas  of  the  intensity  and  direction,  as  well  as  of 
the  character,  of  sounds,  that  the  deceptions  of  the  Ventriloquist  are  founded. 

789.  The  Auditory  sense,  like  the  visual,  may  vary  considerably  among  dif- 
ferent individuals,  both  as  regards  its  general  acuteness,  and  as  respects  its  dis- 
criminative power  for  particular  classes  of  impressions.  Much  depends  upon 
the  habit  of  attention  to  its  indications;  and  thus  it  comes  to  pass,  that  the  power 
of  hearing  very  faint  sounds  and  of  recognizing  their  source,  becomes  augmented 


SENSE    OF    HEARING.  705 

to  a  wonderful  degree  in  those  individuals  who  are  obliged  to  trust  to  the  know- 
ledge thus  acquired  for  the  direction  of  their  own  actions ;  whilst,  in  like  man- 
lier, the  power  of  distinguishing  slight  differences  in  the  pitch  of  sounds,  may 
be  so  cultivated  (where  it  is  not  congenitally  deficient)  as  to  attain  an  intensity 
that  seems  very  extraordinary  to  those  who  have  not  accustomed  themselves  to 
listen  for  them.  The  general  cultivation  of  this  sense  is  perhaps  most  remark- 
able in  blind  persons,  who  have  enabled  themselves,  by  reliance  upon  it,  to  walk- 
about freely,  even  in  the  crowded  thoroughfares  of  the  Metropolis ;  and  who  are 
not  only  able  to  judge  of  the  habits  of  individuals  whom  they  meet,  by  the 
sound  of  their  footsteps  (at  once  recognizing,  for  instance,  the  footstep  of  a 
policeman  on  duty),  but  can  even  tell  when  they  are  passing  a  stationary  object 
(such  as  a  lamp-pest),  provided  it  be  as  high  as  the  ear  or  nearly  so,  by  the  re- 
verberation of  the  sound  of  their  own  footsteps,  and  can  discriminate  between  a 
lamp-post  and  a  man  standing-still  in  the  position  of  one,  by  the  same  means.1 
The  effect  of  habitual  attention  in  increasing  the  discriminative  power  for  im- 
pressions of  one  particular  kind,  is  perhaps  best  seen  in  the  ability  which  is  pos- 
sessed by  certain  Conductors  of  orchestral  performances,  to  detect  the  slightest 
departure  from  time  or  tune  in  the  sound  of^any  one  of  (perhaps)  a  hundred 
instruments  that  are  simultaneously  sounding,  and  to  fix  without  hesitation  upon 
the  faulty  instrumentalist. —  There  seems  to  be  a  great  analogy  between  the 
power  of  distinguishing  colours,  and  that  of  discriminating  musical  tones;  and 
whilst  we  find  that  some  persons  are  endowed  with  the  latter,  which  is  commonly 
known  as  a  '  musical  ear/  in  a  degree,  that  renders  it  a  source  of  great  discom- 
fort to  them  (since  every  discordant  sound  is  a  positive  torment),  others  are  alto- 
gether destitute  of  it, — the  deficiency  being  very  analogous  to  the  l  colour-blind- 
ness' formerly  described  (§  770).  It  is  not  a  little  curious,  that  the  two  defects 
are  occasionally  co-existent  in  the  same  individuals.2 

790.  Some  facts  of  much  interest  have  lately  been  ascertained,  in  regard  to 
an  occasional  difference  in  the  rapidity  of  the  perception  of  sensory  impressions, 
received  through  the  Eye  and  through  the  Ear  respectively.     These  facts  are  the 
result  of  comparisons  made  amongst  different  Astronomical  observers,  who  may 
be  watching  the  same  visual  phenomenon,  and   'timing'  their  observations  by 
the  same  clock ;  for  it  has  been  remarked,  that  some  persons  see  the  same  occur- 
rence, a  third  or  even  a  half  of  a  second  earlier  than  others.     There  is  no  reason 
to  suppose  from  this,  however,  that  there  is  any  difference  in  the  rate  of  trans- 
mission of  the  sensory  impressions  in  the  two  nerves.     The  fact  seems  rather  to 
be,  that  the  Sensorium  does  not  readily  perceive  two  impressions  of  different  kinds 
with  equal  distinctness ;  and  that,  when    several  such  impressions  are  made  on 
the  senses  at  the  same  time,  the  mind  takes  cognizance  of  one  only,  or  perceives 
them  in  succession.     When,  therefore,  both  sight  and  hearing  are  directed  sim- 
ultaneously to  two  objects,  the  communication   of  the  impression  through  one 
sense  will  necessarily  precede  that  made  by  the  other.     The  interval  between  the 
two  sensations  is  greater  in  some  persons  than  in  others ;  for  some  can  receive 
and  be  conscious  of  many  impressions,  seemingly  at  the  sfime  moment;  whilst 
in  others  a  perceptible  space  must  elapse.     The  '  personal  equation '  of  each  ob- 
server in  an  Observatory,  has,  therefore,  to  be  determined  and  allowed-for. 

791.  Amongst  other  important  offices  of  the  sense  of  Hearing,  is  that  of  sup- 
plying the  sensations  by  which  the  Voice  is  regulated.     It  is  well  known  that 
those  who  are  born  entirely  deaf,  are  also  dumb;  that  is,  they  do  not  spontane- 
ously or  imitatively  form  articulate  sounds,  though  not  the  least  defect  may  exi.-t 
in  their  organs  of  voice.     Hence  it  appears  that  the  vocal  muscles  are  usually 
guided  in  their  action  by  the  sensations  received  through  the  Ears,  in  the  same 

1  See  the  account  of  a  blind  boot-lace  seller  given  by  Mr.  H.  Mayhew,  in  his  "  Londoii 
Labour  and  the  London  Poor,"  vol.  i.  p.  402. 

9  See  a  collection  of  such  cases  by  Dr.  Pliny  Earle,  in  "Amer.  Journ.  of  Med.  Sci.," 
rol.  xxxv. 

45 


706  OF    MUSCULAR    MOVEMENTS. 

manner  as  other  muscles  are  guided  by  the  sensations  received  through  them 
selves ;  but  when  the  former  are  deficient,  the  action  of  the  vocal  muscles  may  be 
guided  by  the  latter  (§  542). 


CHAPTER  XIII. 

OF     MUSCULAR     MOVEMENTS. 

1.  Voluntary  and  Involuntary  Movements. 

792.  By  far  the  larger  proportion  of  the  Muscular  apparatus  of  the  Human 
Body,  may  be  considered  in  the  light  of  an  instrument  whereby  the  Nervous 
System  is  enabled  to  give  motion  to  its  parts,  and  thus  to  effect  those  changes  in 
its  relation  to  the  external  world,  which  are  requisite  for  its  physical  well-being, 
or  which  are  the  expressions  of  its  psychical  powers.  There  is  probably  no  part 
of  the  Muscular  system,  which  is  altogether  beyond  the  pale  of  Nervous  agency; 
but  a  tolerably-definite  line  of  demarcation  may  be  drawn,  both  structurally  and 
functionally,  between  the  two  primary  subdivisions  of  this  system  :  in  the  first 
of  which,  the  Muscular  apparatus  of  Organic  Life,  the  actions  are  but  little 
dependent  upon  nervous  agency;  whilst  in  the  second,  the  Muscular  apparatus 
of  Animal  Life,  scarcely  any  action  takes-place,  but  what  is  called-forth  by 
nerve-force. — The  First  group  consists  of  the  Muscular  envelopes  which  sur- 
round the  various  open  cavities  of  the  body,  and  which  form  part  of  its  general 
investment;  its  office  being  to  aid  in  the  performance  of  the  Organic  functions, 
by  giving  motion  to  the  contents  of  the  cavities,  or  by  maintaining  a  proper  state 
of  tension  around  them  :  and  it  is  composed  almost  entirely  of  the  non-striated 
or  smooth  form  of  muscular  fibre  (PRINC.  OF  GEN.  PHYS.,  Am.  Ed.),  the  only 
marked  exception  being  in  the  case  of  the  Heart.  Under  this  category  rank  the 
proper  muscular  coat  of  the  alimentary  canal,  from  its  commencement  in  the  oeso- 
phagus to  its  termination  at  the  anus;  the  muscular  coats  of  the  gland-ducts  which 
discharge  themselves  into  this ;  the  muscular  fibres  of  the  trachea  and  bronchial 
tubes;  the  muscular  substance  of  the  heart,  and  the  muscular  coats  of  the 
blood-vessels  and  absorbents  generally ;  the  muscular  walls  of  the  ureters,  blad- 
der, urethra,  and  vasa  deferentia  in  the  male,  and  of  the  ureters,  bladder,  urethra, 
fallopian  tubes,  uterus,  and  vagina  of  the  female;  and  finally,  the  muscular  sub- 
stance of  the  skin.  With  regard  to  nearly  all  these  parts,  which  are  supplied 
with  nerves  (for  the  most  part)  by  the  Sympathetic  (Chap,  xv.)  rather  than  by 
the  Cerebro-spinal  system,  it  is  difficult  to  obtain  evidence  that  Nervous  agency 
has  any  participation  in  their  usual  operations ;  and  all  the  evidence  yet  adduced 
tends  only  to  show,  that  contractions  may  be  excited  through  this  instrumen- 
tality, wo*  that  they  habitually  are  so  ;  their  ordinary  contractions  being  produced 
either  by  their  own  motility  (§  242),  or  by  stimuli  directly  applied  to  them- 
selves.— The  Second  of  the  above-named  divisions  consists  of  all  those  Muscles 
which  are  usually  styled  '  voluntary/  since  they  can  be  put  or  retained  in  action 
by  the  mandates  of  the  Will,  through  the  instrumentality  of  the  Cerebro-spinal 
system  of  nerves ;  but  besides  these,  it  includes  a  large  group  of  muscles  (those, 
namely,  that  are  concerned  in  the  acts  of  Deglutition,  Respiration,  Vomiting, 
Parturition,  Defecation,  and  Urination),  over  which  the  Will  exerts  only  a  par- 
tial control,  their  activity  being  usually  called  forth  automatically.  It  would 
seem  as  if  this  group  were  placed  under  the  same  conditions,  as  regards  their 
dependence  on  Nervous  agency,  with  those  more  properly  termed  voluntary,  in 
order  that  the  Will,  which  is  altogether  powerless  over  the  Muscular  apparatus 
of  Organic  Life,  may  bring  their  operations  into  harmony  with  the  general  re- 
quirements of  the  system ;  the  functions  in  question  being  thosf  Trhich  constitute 


VOLUNTARY  AND  INVOLUNTARY  MOVEMENTS.   707 

(so  to  speak)  the  meeting-points  between  the  Organic  and  the  Animal  life.  For 
as  we  descend  through  the  Zoological  scale,  we  find  that  they  lose  more  and  more 
of  the  character  they  possess  in  Man,  becoming  more  and  more  exclusively  auto- 
matic, and  at  last  being  even  transferred  from  the  more  elaborate  mechanism  of 
muscular  contraction,  to  the  simple  operation  of  ciliary  vibration.1  Nearly  all 
those  muscles  in  the  Human  body,  which  are  ordinarily  called  into  action  by  the 
Cranio-Spinal  nerves,  are  composed  of  striated  fibre ;  the  most  remarkable  ex- 
ception being  the  muscular  structure  of  the  Iris.  And  it  is  peculiarly  charac- 
teristic of  them,  that  whilst  forcible  and  united  contractions  of  all  the  fasciculi 
at  once,  are  called-forth  by  irritating  their  nerves,  the  effect  of  direct  stimulation 
is  limited  to  the  fasciculus  irritated. 

793.  It  is  obvious  from  what  has  preceded,  that  the  system  of  classifying  the 
Muscles  under  the  categories  of  voluntary  and  involuntary,  cannot  be  consis- 
tently maintained.     It  is  quite  true  that  all  the  Muscles  of  Organic  Life  may  be 
truly  styled  'involuntary;'  for  although  they  are  capable  of  being  influenced  by 
emotional  and  ideational  states  of  mind  (§  829),  yet  the  Will  cannot  exert  any 
direct  influence  upon  them,  only  affecting  them  indirectly  by  its  power  of  deter- 
mining these  states.     But  over  those  Muscles,  also  ministering  to  the  Organic 
functions,  and  doing  so  in  obedience  to  impulses  purely  automatic,  which  are 
called  into  action  by  the  Cranio-Spinal  nerves,  the  Will,  as  we  have  seen,  exerts 
some  power ;  and  such,  therefore,  cannot  be  properly  regarded  as  involuntary, 
since  the  Will  can  influence  their  state ;  whilst  they  are  far  from  being  truly  vol- 
untary, since  the  Will  cannot  control  their  tendency  to  automatic  action  beyond 
a  certain  limited  amount  (§  802).     On  the  other  hand,  every  one  of  the  Muscles 
usually  styled  voluntary,  because  ordinarily  called  into  action  by  the  Will,  is 
liable  to  be  thrown  into  action  involuntarily  ;  either  by  an  Excito-motor  stimulus, 
as  in  tetanic  convulsions,  or  by  Consensual  action,  as  in  tickling,  or  Emotionally, 
as  in  laughter  or  rage,  or  simply  Ideationally,  as  in  somnambulism  and  analogous 
states.     Hence  although  there  are  certain  groups  of  muscles  which  are  more 
frequently  acted-on  by  the  Will  than  by  any  other  impulse,  and  certain  others 
which  are  more  frequently  played-on  by  the  Emotions,  and  so-on,  it  becomes 
obvious  that  every  muscle  called  into  contraction  by  the  Cranio-Spinal  nervous 
system  is  capable  of  receiving  its  stimulus  to  movement  from   any  of  these 
sources ;  the  nerve-force  transmitted  along  the  motor-fibres,  being  issued  either 
from  the  Spinal  Cord,  from  the  Sensory  Ganglia,  or  from  the  Cerebrum,  as  the 
case  may  be,  but  being  in  its  nature  and  effects  the  same  in  every  instance. 

794.  The  grouping  or  combination  of  Muscular  actions,  which  takes  place  in 
almost  every  movement  of  one  part  of  the  body  upon  another,  must  be  attributed, 
not  to  any  peculiar  sympathy  among  the  Muscles  themselves,  but  to  the  mode  in 
which  they  are  acted-on  by  the  Nervous  Centres.     This  is  most  obviously  the 
case  with  regard  to  those  of  the  primarily-automatic  class ;  but  it  can  scarcely  be 
doubtful  as  to  those  of  the  secondarily-automatic  kind  (§  514),  such  as  walking, 
which,  though  at  first  directed  by  the  Will,  come  by  habit  to  be  performed  under 
conditions  essentially  the  same  with  the  preceding ;    and  when  it  is  borne  in 
mind  that  even  in  voluntary  movements    the  Will  cannot   single-out  any   one 
muscle  from  the  group  with  which  it  usually  co-operates,  so  as  to  throw  this  into 
separate  contraction,  but  is  limited  to  determining  the  result  (§  545),  it  seems 
pretty  obvious  that  even  here  the  grouping  is  effected  by  the  endowments  of 
those  Automatic  centres  from  which  all  the  motor  impulses  immediately  proceed 
to  the  muscles,  and  not  by  Cerebral  agency.     In  fact  the  whole  process  by  which 
we  acquire  the  power  of  adapting  our  muscular  actions  to  the  performance  of 
some  new  kind  of  movement, — as  in  the  case  of  an  infant  learning  to  walk,  a 

1  Thus  in  the  Oyster  and  other  Bivalve  Mollusks,  which  have  a  complicated  digestive 
circulating,  and  respiratory  apparatus,  food  is  brought  to  the  mouth,  faecal  matters  are 
expelled  from  the  anus,  and  a  constant  current  of  water  is  made  to  sweep  over  the  respira- 
tory surface,  entirely  by  ciliary  motion. 

J 


708  OF    MUSCULAR   MOVEMENTS. 

child  learning  to  write,  an  artizan  learning  some  occupation  which  requires  nice 
manipulation,  a  musical  performer  learning  a  new  instrument,  and  so  on, — is 
found,  when  attentively  studied,  to  indicate  that  the  Will  is  far  from  having  that 
direct  and  immediate  control  over  the  contractions  of  the  Muscles,  which  it  is 
commonly  reputed  to  possess;  and  that  the  operation  really  consists  in  the  grad- 
ual establishment  of  a  new  grouping  of  the  separate  actions,  in  virtue  of  which, 
the  stimulus  of  a  Volitional  determination,  acting  under  the  guidance  of  the 
muscular  sensations  (§  541),  henceforth  calls  into  contraction  the  group  of  mus- 
cles whose  agency  is  competent  to  carry  that  determination  into  effect.  For  how-  - 
ever  amenable  any  set  of  muscles  (as  those  of  the  arm  and  hand)  may  have 
become  to  the  direction  of  the  Will,  in  any  operations  which  they  have  been 
previously  accustomed  to  perform,  it  is  only  after  considerable  practice  that  they 
can  be  trained  to  any  method  of  combined  action  which  is  entirely  new  to  them; 
and  even  if  we  attempt  to  bring  our  anatomical  knowledge  into  use  for  such  a 
purpose,  by  mentally  fixing  upon  certain  muscles  whose  action  we  wish  to  inten- 
sify and  to  associate  with  those  of  others,  we  find  that  such  a  method  of  proceed- 
ing affords  no  assistance  whatever,  but  rather  tends  to  impede  our  progress,  by 
drawing-off  the  attention  from  the  'guiding  sensations '  (visual,  muscular,  &c.,) 
which  are  the  only  regulators  that  can  be  depended-upon  for  determining  the 
due  performance  of  the  volitional  mandate. — Hence  we  are  led  by  these  consid- 
erations, as  by  those  stated  in  the  preceding  paragraph,  to  the  conclusion,  that 
the  agency  which  directly  affects  the  muscles  is  of  the  same  kind,  and  that  it 
operates  under  the  same  instrumental  conditions,  whatever  be  the  primal  source 
of  the  motor  power.  And  in  watching  the  gradual  acquirement  of  the  capacity 
for  different  kinds  of  movement,  during  the  periods  of  Infancy  and  Childhood  in 
the  Human  subject,  we  find  everything  to  confirm  this  conclusion.  For  it 
becomes  obvious  that  the  acquirement  of  Voluntary  power  over  the  movements 
of  the  limbs,  is  just  as  gradual  as  it  is  over  the  direction  of  the  thoughts  (§  677)  ; 
all  the  activity  of  the  body,  as  well  as  of  the  mind,  being  in  the  first  instance 
automatic ;  and  the  Will  progressively  extending  its  domination  over  the  former, 
as  over  the  latter,  until  it  brings  under  its  control  all  those  muscular  movements 
which  are  not  immediately  required  for  the  conservation  of  the  body,  and  turns 
them  to  its  own  uses.1 

2.    Of  the  Symmetry  and  Harmony  of  Muscular  Movements. 

795.  It  might  have  been  not  unreasonably  supposed,  d  priori,  that  those 
muscles  would  have  been  most  readily  put  into  simultaneous  contraction,  which 
correspond  to  each  other  on  the  two  sides  of  the  body;  in  other  words,  that 
symmetrical  movements  would  be  those  most  readily  performed.  Such,  however, 
is  by  no  means  the  case ;  for  in  many  of  our  most  familiar  actions,  we  consenta- 
neously exert  different  muscles  on  the  two  sides  of  the  body.  Thus,  in  ordinary 
walking,  we  advance  one  leg  whilst  we  push-backwards  (so  as  to  urge  the  body 

1  The  aptitude  which  is  acquired  by  practice,  for  the  performance  of  certain  actions  that 
were  at  first  accomplished  with  difficulty,  seems  to  result  as  much  from  a  structural  change 
which  the  continual  repetition  of  them  occasions  in  the  Muscle,  as  in  the  habit  which  the 
Nervous  system  acquires  of  exciting  the  movement.  Thus  almost  every  person  learning  to 
play  on  a  musical  instrument,  finds  a  difficulty  in  causing  the  two  shorter  fingers  to  move 
independently  of  each  other  and  of  the  rest ;  this  is  particularly  the  case  in  regard  to  the 
ring-finger.  Any  one  may  satisfy  himself  of  the  difficulty,  by  laying  the  palm  of  the  hand 
flat  on  a  table,  and  raising  one  finger  after  the  other,  when  it  will  be  found,  that  the  ring- 
finger  can  scarcely  be  lifted  without  disturbing  the  rest, — evidently  from  the  difficulty  of 
detaching  the  action  of  the  portion  of  the  extensor  communis  digitorum,  by  which  the 
movement  is  produced,  from  that  of  the  remainder  of  the  muscle.  Yet  to  the  practised 
musician,  the  command  of  the  Will  over  all  the  fingers  becomes  nearly  alike ;  and  it 
can  scarcely  be  doubted  that  some  change  in  the  structure  of  the  muscle,  or  a  new  devel- 
opment of  its  nerve-fibres,  takes  place,  which  favours  the  isolated  operation  of  its  several 
Jivisions. 


OF    THE    SYMMETRY    AND    HARMONY    OF    MUSCULAR    MOVEMENTS.     709 

forwards)  with  the  other ;  and  in  the  swinging  of  the  arms,  which  is  in  most 
persons  a  natural  part  of  this  mode  of  locomotion,  the  arms  of  the  two  sides  move 
forwards  and  backwards  alternately,  and  the  arm  of  either  side  is  advanced,  not 
with  the  leg  of  its  own  side,  but  with  that  of  the  opposite  side, — any  other  com- 
bination being  felt  as  unnatural,  and  being  only  performed  by  a  conscious  effort. 
Now  it  is  plain  that  this  grouping  of  the  muscular  movement,  arises  out  of  its 
felt  conformity  to  the  end  in  view,  and  that  it  is  regulated  by  the  guiding  sensa- 
tions which  indicate  to  us  the  progression  and  balance  of  the  body.  The  infant, 
in  learning  to  walk,  is  prompted  by  an  instinctive  tendency  to  put  one  foot  be- 
fore the  other,  as  may  be  noticed  at  a  very  early  period,  when  it  is  first  held  so 
as  to  feel  the  ground  with  its  feet;  and  in  attempting  to  balance  itself  when  first 
left  to  stand  alone,  it  moves  its  arms  with  a  like  intuitive  impulse,  not  based 
upon  experience.  All  that  experience  does,  in  either  case,  is  to  give  that  pre- 
cise adjustment  to  the  muscular  action,  which  makes  it  perfectly  conformable  to 
the  indications  afforded  by  the  muscular  sensations.  Thus,  if  we  advance  each 
arm  with  its  corresponding  leg,  we  feel  that  the  balance  of  the  body  is  not  nearly 
as  readily  maintained,  as  it  is  when  we  advance  the  arm  with  the  leg  of  the 
opposite  side  ;  and  thus,  without  any  design  or  voluntary  determination  on  our 
own  parts,  the  former  comes  to  be  our  settled  habit  of  action.  This  kind  of 
adjustment,  in  the  case  before  us,  is  by  no  means  limited  to  the  muscles  of  the 
limbs ;  for  there  is  scarcely  any  muscle  of  the  trunk  or  head,  that  is  not  exerted 
with  some  degree  of  consentaneous  energy,  however  unconsciously  to  ourselves, 
in  the  act  of  walking.  The  difficulty  which  would  attend  the  voluntary  harmoni- 
zation of  all  these  separate  actions  is  remarkably  evinced  by  the  fact,  that  no 
mechanist,  however  ingenious,  has  ever  succeeded  in  constructing  an  automaton 
that  could  walk  like  Man;  the  alternate  shifting  of  the  centre  of  gravity  from 
one  side  to  the  other,  upon  so  small  a  base  as  the  human  foot  affords  simultane- 
ously with  the  movement  in  advance,  constituting  the  great  difficulty  of  biped 
progression.  But  all  this  adjustment  is  effected  in  our  own  organisms,  for  us, 
rather  than  by  us;  the  act  of  harmonization,  when  once  fully  mastered,  being 
attended  with  no  effort  to  ourselves ;  but  the  whole  series  of  complex  movements 
being  performed  in  obedience  to  the  simple  determination  to  walk,  under  the 
automatic  guidance  of  the  senses,  which  instantly  reveal  to  us  any  imperfection 
in  the  performance. — The  same  view  extends  itself  readily  to  other  combinations 
of  dissimilar  and  non-symmetrical  movements  which  are  less  natural  to  Man,  but 
which  may  be  readily  acquired  artificially  if  they  all  harmonize  in  a  common  pur- 
pose, and  are  under  the  guidance  of  the  same  set  of  sensations.  Thus,  the  per- 
former on  the  Organ  uses  the  several. fingers  of  his  two  hands  to  execute  as  many 
different  movements  (in  very  different  positions,  it  may  be)  on  the  l  manual'  keys, 
one  of  his  feet  may  be  on  the  'swell'  pedal,  and  the  other  may  be  engaged  in 
playing  on  the  *  pedal '  keys ;  but  all  these  diverse  actions  are  harmonized  by 
their  relation  to  the  same  set  of  auditory  sensations ;  and  if  the  result  be  not 
that  which  the  performer  anticipated,  an  immediate  correction  is  made. 

796.  It  would  be  easy  to  multiply  instances  of  the  same  kind,  all  illustrative 
of  the  general  principle,  that  the  facility  with  which  we  voluntarily  combine 
different  movements  is  chiefly  determined,  not  by  their  symmetrical  character, 
but  by  their  conformableness  to  a  common  end,  and  by  the  harmony  of  their 
guiding  sensations  with  reference  to  that  end;1  but  it  will  be  desirable  to  dwell 

*  Two  simple  examples,  however,  may  be  cited,  of  the  difficulty  whiou  attends  the 
simultaneous  performance  of  movements  that  are  not  harmonious.  If  we  attempt  to  elevate 
one  eyelid  whilst  we  are  depressing  the  other,  we  find  that  a  considerable  effort  is  required 
to  accomplish  the  action,  although  the  elevation  or  depression  of  both  eyelids  together  is 
performed  with  so  little  effort  that  we  are  scarcely  conscious  of  it;  and  the  difficulty  is 
increased,  if  we  half-shut  both  eyes,  and  then  try  to  close  one  and  to  open  the  other.  So 
if  we  try  to  move  our  two  hands,  as  if  they  were  simultaneously  winding  cord  in  opposite 
directions  upon  two  reels  placed  in  front  of  us,  we  shall  find  ourselves  unable  to  do  so 
without  a  constant  exercise  of  the  attention,  and  even  then  but  slowly  and  with  difficulty  ; 


710 


OF    MUSCULAR    MOVEMENTS. 


[Fio.  185. 


particularly  on  the  Movements  of  the  JEye,  as  presenting  certain  points  of  peculiar 
interest,  some  of  which  have  an  important  bearing  on  Surgical  practice. — It  will 
be  recollected  that,  in  the  Human  Orbit,  six  muscles  for  the  movements  of  the 
eyeball  are  found;  the  four  Recti,  and  the  two  Oblique  muscles.  The  precise 
actions  of  these  are  not  easily  established  by  experiment  on  the  lower  animals ; 
for  in  all  those  which  ordinarily  maintain  the  horizontal  position,  there  is  an 
additional  muscle,  termed  the  retractor,  which  embraces  the  whole  posterior  por- 
tion of  the  globe,  and  passes-backwards  to  be  attached  to  the  bottom  of  the  orbit.1 
If  the  origin  and  insertion  of  the  four  Recti  muscles  be  examined,  however,  no 

doubt  can  remain  that  each  of  them,  act- 
ing singly,  is  capable  of  causing  the  globe 
to  revolve  in  its  own  direction, — the  supe- 
rior rectus  causing  the  pupil  to  turn  up- 
wards,— the  internal  rectus  causing  it  to 
roll  towards  the  nose,  —  and  so  on.  A 
very  easy  and  direct  application  of  the  laws 
of  mechanics  will  further  make  it  evident 
to  us,  that  the  combined  action  of  any  two 
of  the  Recti  muscles  must  cause  the  pupil 
to  turn  in  a  direction  intermediate  be- 
tween the  lines  of  their  single  action  ;  and 
that  any  intermediate  position  may  thus 
be  given  to  the  eyeball  by  these  muscles 
alone.  This  fact,  which  has  not  received 
the  attention  it  deserves,  leads  us  to  per- 
ceive that  the  Oblique  muscles  must  have 
some  supplementary  function.  It  may  be 
objected  that  this  is  a  theoretical  state- 
ment only;  and  that  there  may  be  some 
practical  obstacle  to  the  performance  of 
diagonal  movements  by  the  Recti  mus- 
cles, which  renders  the  assistance  of  the 
Obliques  essential  for  this  purpose.  But 
to  this  it  may  be  replied,  that  no  sinyle 
muscle  can  direct  the  ball  either  downwards 
and  inwards,  or  upwards  and  outwards : 
and  that,  as  we  have  good  reason  to  believe 

these  movements  to  be  effected  by  the  combination  of  the  Recti  muscles,  there  is  no 
reason  why  the  other  diagonal  movements  should  not  also  be  due  to  them. — The 
most  probable  account  of  the  functions  of  the  Oblique  muscles  of  the  eye,  seems 
to  be  that  which  was  long  ago  suggested  by  John  Hunter,  and  which  has  received 
confirmation  from  the  experiments  of  Dr.  G.  Johnson.2  It  has  been  just  shown 
that  the  action  of  the  Recti  muscles  upon  the  pupil,  is  such  as  to  cause  it  to 

although  the  very  same  movements  may  be  separately  performed,  or  both  hands  may  be 
made  thus  to  move  in  the  same  direction,  with  the  greatest  facility. 

1  This  muscle  is  most  developed  in  Ruminating  animals,  which,  during  their  whole 
time  of  feeding,  carry  their  heads  in  a  dependent  position.  In  most  Carnivorous  animals 
instead  of  the  complete  hollow  muscular  cone  (the  base  inclosing  the  eyeball,  whilst  the 
apex  surrounds  the  optic  nerve),  which  we  find  in  the  Ruminants,  there  are  four  distinct 
strips,  almost  resembling  a  second  set  of  recti  muscles,  but  deep-seated,  and  inserted  into 
the  posterior  instead  of  the  anterior  portion  of  the  globe.  It  is  obvious  that  the  actions  of 
these  must  greatly  affect  the  results  of  any  operations  which  we  may  perform  upon  the 
other  muscles  of  the  Orbit;  and,  as  it  is  impossible  to  divide  the  former,  without  com- 
pletely separating  the  eye  from  its  attachments,  we  have  no  means  of  correcting  such 
results  but  by  reasoning  alone.  Experiments  upon  animals  of  the  order  Quadrumana, 
most  nearly  allied  to  Man,  would  be  more  satisfactory ;  as  in  them,  the  retractor  muscle 
is  almost  or  entirely  absent. 

3  "  Cyclopaedia  of  Anatomy  and  Physiology,"  vol.  iii.  p.  790. 


The  muscles  of  the  eyeball ;  the  view  is 
taken  from  the  outer  side  of  the  right  orbit. 
1.  A  small  fragment  of  the  sphenoid  bone 
around  the  entrance  of  the  optic  nerve  into 
the  orbit.  2.  The  optic  nerve.  3.  The 
globe  of  the  eye.  4.  The  levator  palpebras 
muscle.  5.  The  superior  oblique  muscle. 
6.  Its  cartilaginous  pulley.  7.  Its  reflected 
tendon.  8.  The  inferior  oblique  muscle  ;  the 
small  square  knob  at  its  commencement  is  a 
piece  of  its  bony  origin  broken  off.  9.  The 
superior  rectus.  10.  The  internal  rectus  al- 
most concealed  by  the  optic  nerve.  11.  Part 
of  the  external  rectus,  showing  its  two  heads 
of  origin.  12.  The  extremity  of  the  external 
rectus  at  its  insertion  ;  the  intermediate  por- 
tion of  the  muscle  having  been  removed. 
13.  The  inferior  rectus.  14.  The  tunica  al- 
buginea,  formed  by  the  expansion  of  the  ten- 
dons of  the  four  recti.] 


MOVEMENTS    OF    THE    EYEBALL.  711 

revolve  in  any  given  direction  :  and  this  is  put  in  force,  not  merely  to  alter  the 
range  of  vision,  the  head  remaining  stationary ;  but  also  to  keep  the  range  of  vision' 
the  same,  and  to  cause  the  images  of  the  objects  upon  which  our  gaze  is  fixed,  still 
to  fall  upon  the  same  parts  of  the  retinae,  by  maintaining  the  position  of  the  eyes 
when  the  head  is  moved  upwards,  downwards,  from  side  to  side,  or  in  any  inter- 
mediate direction  (§  546).  But  these  muscles  are  not  able  to  rotate  the  eyeball 
upon  its  antero-posterior  axis;  and  such  rotation  is  manifestedly  necessary  to 
preserve  the  fixed  position  of  the  eyeball,  and  consequently  to  keep  the  image  of 
the  object  under  survey  upon  the  same  part  of  the  retina,  when  the  head  is 
inclined  sideways,  or  is  bowed  towards  one  shoulder  and  then  towards  the  other. 
It  appears  from  the  experiments  of  Dr.  Gr.  Johnson,  that  the  action  of  the 
Oblique  muscles  is  exactly  adapted  to  produce  such  a  rotation  :  the  Inferior  oblique 
in  its  contraction,  causing  the  eyeball  to  move  upon  its  antero-posterior  axis,  in  such 
a  manner  that  a  piece  of  paper,  placed  at  the  outer  margin  of  the  cornea,  passes 
downwards  and  then  inwards  towards  the  nose ;  and  the  Superior  oblique  effecting 
precisely  the  reverse  action,  the  paper  at  the  outer  margin  of  the  cornea  passing 
first  upwards  and  then  inwards.  There  was  not  the  slightest  appearance  in  these 
experiments,  of  elevation,  depression,  or  adduction,  of  the  cornea,  as  a  result  of  the 
action  of  the  Oblique  muscles ;  all  these  movements  being  attributable  to  the 
Recti  alone.1 

797.  On  studying  the  Voluntary  movements  of  the  Eyeballs,  we  are  led  to 
perceive  that  they  are  not  so  much  symmetrical  as  harmonious  ;  that  is  to  say, 
the  corresponding  muscles  on  the  two  sides  are  rarely  in  action  at  once ;  whilst 
such  a  harmony  or  consent  exists  between  the  actions  of  the  muscles  of  the  two 
orbits,  that  they  work  to  one  common  purpose,  namely,  the  direction  of  both  eyes 
towards  the  required  object.  They  may  be  arranged  under  two  groups ;  the  first 
comprising  those  which  are  alike  harmonious  and  symmetrical ;  the  second  in- 
cluding those  which  are  harmonious  but  not  symmetrical.  To  the  first  group 
belong  the  following. — 1.  Both  eyeballs  are  elevated,  by  the  contraction  of  the 
two  Superior  liecti. — 2.  Both  eyeballs  are  depressed,  by  the  conjoint  action  of  the 
Inferior  Recti  muscles. — 3.  Both  are  drawn  directly  inwards,  or  inwards  and 
downwards,  as  when  we  look  at  an  object  placed  on  or  near  the  nose;  this  move- 
ment is  effected  by  the  action  of  the  Internal  Recti  of  the  two  sides,  with  or  with- 
out the  Inferior  Recti.  It  is  evidently  symmetrical,  but  might  seem  at  first  sight 
not  to  be  harmonious,  because  the  eyes  do  not  move  together  towards  one  side  or 
the  other;  it  is,  however,  really  harmonious,  since  it  directs  their  axes  towards 
the  same  point.2 — Now  it  is  to  be  observed,  with  regard  to  these  movements,  that 
we  can  never  effect  them  in  antagonism  with  each  other,  or  with  those  of  other 
muscles.  We  cannot,  for  example,  raise  one  eye  and  depress  the  other;  nor  can 
we  raise  or  depress  one  eye,  when  we  adduct  or  abduct  the  other.  The  explana- 
tion of  this  will  be  found  in  the  fact,  that  we  can  never,  by  so  doing,  direct  the 
eyes  to  the  same  point. — The  harmonious  but  unsymmetrical  movements,  form- 
ing the  second  class,  are  those  in  which  the  Internal  and  External  Recti  of  the 

1  The  Author  has  been  informed  by  his  friend  Mr.  Bowman,  that  he  has  met  with  two 
cases  of  double  vision,  in  which  the  defect  was  not  experienced  when  the  head  was  held 
erect  or  turned  upon  its  vertical  axis,  but  only  when  it  was  inclined  to  the  one  shoulder  or 
the  other.  Such  a  peculiarity  is  readily  explained  on  the  above  hypothesis,  or  by  the  sup- 
position that  one  or  both  of  the  Oblique  muscles  of  one  eye  was  paralysed,  so  that  the 
normal  rotation  was  not  performed  on  that  side. 

a  Some  persons  can  effect  this  voluntarily  to  a  greater  extent  than  others ;  but  even  then, 
they  can  only  accomplish  it  by  fixing  the  gaze  upon  some  object  situated  between  the  eyes ; 
and  cannot  call  the  adductor  muscles  into  combined  action  in  perfect  darkness,  or  if  the 
lids  be  closed.  Even  those  who  have  the  least  power  of  effecting  this  extreme  convergence 
by  at  once  directing  the  eyes  towards  a  very  near  object,  can  accomplish  it  by  looking  at 
an  object  placed  at  a  moderate  distance,  and  gradually  bringing  this  nearer  to  the  nose, 
keeping  the  eyes  steadily  fixed  upon  it.  The  unwonted  character  of  the  movement  is 
shown  in  this, — that  it  can  only  be  maintained,  even  for  a  short  time,  by  a  strong  effort, 
producing  a  sense  of  fatigue. 


712  OF    MUSCULAR    MOVEMENTS. 

two  sides  are  made  to  act  together,  either  alone,  or  in  conjunction  with  the  Su- 
perior and  Inferior  Recti.  They  are  as  follows. — 4.  One  eye  is  made  to  revolve 
directly  inwards,  by  the  action  of  its  Internal  Rectus,  whilst  the  other  is  turned 
outwards  by  the  action  of  its  External  Rectus. — 5.  One  eye  is  made  to  revolve 
upwards  and  inwards,  by  the  conjoint  action  of  the  Superior  and  Internal  Recti; 
the  other,  upwards  and  outwards,  by  the  conjoint  action  of  the  Superior  and  Ex- 
ternal Recti. — 6.  One  eye  is  made  to  revolve  downwards  and  inwards,  by  the 
conjoint  action  of  the  Inferior  and  Internal  Recti ;  the  other  downwards  and  out- 
wards, by  the  conjoint  action  of  the  Inferior  and  External  Recti. — In  these 
movements,  two  different  muscles,  the  External  and  Internal  Recti,  are  called 
into  action  on  the  two  sides,  with  or  without  the  superior  and  inferior  Recti  ;  but 
they  are  so  employed  for  the  purpose  of  directing  the  axes  of  the  eyes  towards 
the  same  point;  and  although,  as  just  noticed,  we  can  put  the  two  Internal  Recti 
in  action  together,  we  cannot  voluntarily  cause  the  two  External  Recti  to  contract 
together,  it  not  being  possible  that  any  object  should  be  in  such  a  position  as  to 
require  this  action  for  the  direction  of  the  axes  of  the  eyes  towards  it. 

798.  The  greater  number  of  the  foregoing  movements  may  be  performed  un- 
consciously to  ourselves,  in  obedience  to  a  Voluntary  determination  to  keep  the 
direction  of  the  eyes  fixed,  instead  of  to  give  motion  to  the  eyeballs.     Thus,  if 
we  gaze  steadily  at  an  object  in  front  of  us,  and  then  depress  the  head  forwards 
on  its  transverse  axis,  the  eyeballs  roll  upwards  upon  their  transverse  axes  (1)  by 
the  action  of  the  Superior  Recti,  without  our  being  aware  of  it ;  so  if,  whilst  still 
maintaining  the  same  fixed  gaze,  we  raise  the  head  into  the  vertical  position  and 
then  depress  it  backwards,  the  eyeballs  are  rolled  downwards  (2)* by  the  action  of 
the  Inferior  Recti ;  if,  under  the  same  conditions,  the  bead  be  made  to  rotate  on 
its  vertical  axis  from  side  to  side,  the  eyeballs  will  be  made  to  roll  on  their  ver- 
tical axes  in  the  contrary  direction,  by  the  External  and  Internal  Recti  (4)  of  the 
two  sides  respectively ;  so,  by  causing  the  head  to  move  obliquely  in  the  opposite 
directions,  the  reverse  oblique  movements  (5  and  6)  of  the  eyeballs  are  made  to 
take-place  by  the  continued  fixation  of  the  vision  upon  the  same  object.     To  these 
we  have  to  add  one  more  action,  which  cannot  be  called-forth  in  any  other  mode; 
namely,  that  rotation  of  the  two  eyes  upon   their  antero-posterior  axes,  which 
takes-place  probably  by  the  instrumentality  of  the  Oblique  muscles,  when  we  in- 
cline the  head  to  one  side  or  the  other  by  rotating  it  upon  its  antero-posterior 
axis  (§  796).     In  all  these  movements,  as  in  the  preceding,  the  Will  directs  the 
result;  and  there  is  no  other  difference  between  them,  than  that  which  arises  out 
of  our  consciousness  of  a  change  in  the  one  case,  and  our  unconsciousness  in  the 
other. — The  truly  Involuntary  movements  of  the  eyeballs,  however,  are  performed 
under  very  different  conditions ;  there  being  here  no  purposive  direction  or  fixa- 
tion of  the  gaze;  and  the  muscular  contractions  not  being  determined  by  visual 
sensations,  but  being  called-forth  by  nerve-force  excited  in  some  remote  part.     Of 
this  we  have  an  example  in  the  normal  revolution  of  both  eyes  upwards  and  in- 
wards, which  takes-place  in  the  acts  of  coughing,  sneezing,  winking,  &c. ;  but  far 
more  remarkable  illustrations  are  presented  in  those  abnormal  movements  of  the 
eyeballs,  occurring  in  Convulsive  diseases,  in  which  there  is  neither  harmony  nor 
symmetry. 

799.  It  has  been  stated  to  be  a  condition  of  single  and  distinct  vision,  that  the 
usual  axes  of  the  eyes  should  be  directed  towards  the  object,  in  order  that  its 
picture  should  be  thrown  upon  the  parts  of  the  two  retinas  which  are  accustomed 
to  act  together  (§  760) ;  but  as  this  cannot  take-place  without  the  guidance  of 
visual  sensations,  the  movements  of  the  eyeballs  are  wanting  in  harmony,  when- 
ever the  visual  power  has  been  deficient  from  birth.     This  is  most  remarkably 
the  case,  where  the  deficiency  has  been  so  complete  that  not  even  light  can  be 
distinguished ;  but  the  movements  are  frequently  very  far  from   being  harmo- 
nious, m  cases  of  congenital  cataract,  where  a  considerable  amount  of  light  is  evi- 
dently admitted,  but  where  no  distinct  image  can  be  formed ;  and  in  such  cases, 


MOVEMENTS    OF    THE    EYEBALL: — STRABISMUS.       713 

the  movements  are  most  harmonious  where  the  object  is  bright  or  luminous,  and 
more  vivid  impressions  are  therefore  made  upon  the  retinae.  It  is  no  objection 
to  this  doctrine  to  say,  that  persons  who  have  become  blind  may  still  move  their 
eyes  in  a  harmonious  manner;  since,  the  habit  of  the  association  of  particular 
movements  having  been  once  acquired,  the  guidance  of  the  muscles  may  be 
effected  by  sensations  derived  from  themselves,  in  the  manner  in  which  it  takes- 
place  in  the  laryngeal  movements  of  the  deaf  and  dumb  (§  542);  and,  as  a  mat- 
ter of  fact,  a  want  of  consent  may  often  be  observed  where  the  blindness  is  total. 
The  peculiar  'vacant'  appearance,  which  may  be  noticed  in  the  countenances  of 
persons  completely  deprived  of  sight  by  amaurotic  or  other  affections,  which  do 
not  alter  the  external  aspect  of  the  eyes,  seems  to  result  from  this, — that  theii 
axes  we  parallel,  as  if  the  individual  were  looking  into  distant  space,  instead  of 
presenting  that  slight  convergence  which  must  always  exist  between  them,  when 
the  eyes  are  fixed  upon  a  definite  object.  This  convergence,  which  is  of  course 
regulated  by  the  Internal  Recti,  varies  in  degree  according  to  the  distance  of  the 
object;  and  it  is  astonishing  how  minute  an  alteration  in  the  axes  of  the  eyes  be- 
comes perceptible  to  a  person  observing  them.  For  instance,  A  sees  the  eyes  of 
B  directed  towards  his  face,  but  he  perceives  that  B  is  not  looking  at  him ;  he 
knows  this  by  a  sort  of  intuitive  interpretation  of  the  fact,  that  his  face  is  not  the 
point  of  convergence  of  B's  eyes.  But  if  B,  who  might  have  been  previously 
looking  at  something  nearer  or  more  remote  than  A's  face,  fix  his  gaze  upon  the 
latter,  so  that  the  degree  of  the  convergence  of  the  axes  is  altered,  without  the 
general  direction  of  the  eyes  being  in  the  least  affected,  the  change  is  at  once  per- 
ceived by  the  person  so  regarded;  and  the  eyes  of  the  two  then  meet. — It  is  an 
interesting  confirmation  of  the  principles  here  advocated,  that  when  binocular 
vision  cannot  bo  obtained  by  directing  the  true  axes  of  the  eyes  towards  the  ob- 
ject, as  happens  when  an  opaque  spot  exists  upon  the -centre  of  the  cornea,  or  an 
artificial  pupil  has  been  formed  at  the  margin  of  the  iris,  there  is  an  automatic 
tendency  to  the  neutralization  of  the  mischief,  by  such  an  action  of  the  muscles 
as  shall  turn  the  virtual  axis  of  the  affected  eye  (that  is,  the  axis  in  which  the 
rays  most  directly  enter  the  globe)  towards  the  object,  thus  producing  Strabis- 
mus, but  not  Double  Vision. 

800.  The  physiological  principles  which  have  now  been  stated,  have  an  im- 
portant application  in  the  treatment  of  Strabismus  by  operation;  a  practice  whose 
frequent  want  of  success  is  due  in  great  part  to  the  injudicious  selection  of  cases, 
and  to  the  wrong  measures  pursued. — The  degree  in  which  habit  accustoms  parts 
of  the  retinas  that  did  not  originally  correspond,  to  work-together  harmoniously, 
is  remarkably  shown  by  the  fact,  that  patients  who  have  been  long  affected  with 
Convergent  Strabismus,  and  who  see  equally  well  with  both  eyes  (as  many  do), 
are  not  troubled  with  double  vision.  On  the  other  hand,  when  a  person  whose 
eyes  look  straight  before  him,  is  the  subject  of  a  disorder  which  renders  their  mo- 
tions in  any  degree  irregular,  he  is  at  once  affected  with  double  vision.  The  same 
has  been  frequently  noticed  as  an  immediate  result  of  the  successful  operation  for 
the  cure  of  Strabismus,  where  vision  is  good  in  both  eyes;  for  although  the 
images  were  previously  formed  on  parts  of  the  retinas  which  were  very  far  from 
corresponding  with  each  other,  yet  no  sooner  is  the  position  of  the  eyes  rectified 
(so  that  the  relation  between  the  situation  of  the  images  is  the  same  as  it  would 
be  in  a  sound  eye),  than  the  patient  sees  double.  Now  in  these  cases  the  diffi- 
culty very  speedily  diminishes,  and  the  patient  soon  learns  to  see  single.  That 
there  is  a  greater  tendency  to  consent  between  the  images,  however,  when  they 
are  formed  upon  the  parts  of  the  two  retinas  which  normally  correspond,  may  be 
freely  admitted :  and  this  seems  to  be  a  principle  of  some  importance  in  deter- 
mining the  re-adjustment  of  the  eyes,  after  the  operation  for  Strabismus.  This 
re-adjustment  is  not  always  immediate;  for  after  the  muscle  has  been  freely 
divided,  the  eye  often  remains  somewhat  inverted  for  a  few  days,  gradually  ac 
quiring  its  straight  position.  The  Author  has  known  one  case,  in  which,  aftei 


714  OF    MUSCULAR    MOVEMENTS. 

such  a  degree  of  temporary  inversion  as  seemed  to  render  the  success  of  the  ope- 
ration very  doubtful,  eversion  actually  took-place  for  a  short  time  to  a  consider- 
able extent;  after  which  the  axes  became  parallel,  and  have  remained  soever 
since. — Another  argument  derivable  from  the  results  of  this  operation,  in  favour 
of  the  consensual  movement  being  chiefly  regulated  by  the  correspondence  in  the 
seats  of  the  impressions  on  the  two  retinae,  is,  that  it  is  much  more  successful  in 
those  cases  in  which  the  sight  of  the  most  displaced  eye  is  good,  than  in  those  in 
which  (as  not  unfrequently  happens  from  long  disuse)  it  is  much  impaired.  In 
cases  of  the  latter  class,  the  cure  is  seldom  complete.1 

3.  Energy  and  Rapidity  of  Muscular  Contraction. 

801.  The  energy  of  Muscular  contraction  is  of  course  to  be  most  remarkably 
observed,  in  those  instances  in  which  the  continual  exercise  of  particular  parts 
has  occasioned  an  increased  determination  of  blood  towards  them,  and  in  conse- 
quence a  permanent  increase  of  their  bulk  (§  344  in).  This  has  been  the  case 

1  In  reference  to  this  subject,  the  Author  would  add  that  he  is  well  convinced,  from 
repeated  observation,  that  those  Surgeons  are  in  the  right,  who  have  maintained  that,  in  a 
large  proportion  of  cases,  Strabismus  is  caused  by  an  affection  of  both  sets  of  muscles  or 
nerves,  and  not  of  one  only ;  and  that  it  then  requires,  for  its  perfect  cure,  the  division  of 
the  corresponding  muscles  on  both  sides.     Cases  will  be  frequently  met-with,  in  which  this 
is  evident ;  the  two  eyes  being  employed  to  nearly  the  same  extent,  and  the  patient  giving 
to  both  a  slight  inward  direction,  when  desired  to  look  straight-forwards.     In  general, 
however,  one  eye  usually  looks  straight-forwards,  whilst  the  other  is  greatly  inverted ;  and 
the  sight  of  the  inverted  eye  is  frequently  affected  to  a  considerable  degree  by  disuse ;  so 
that,  when  the  patient  voluntarily  rotates  it  upon  its  proper  axis,  his  vision  with  it  is  far 
from  being  distinct.     Some  Surgeons  have  maintained,  that  the  inverted  eye  is  usually  the 
only  one  in  fault,  and  consider  that  the  division  of  the  tendon  of  its  Internal  Rectus  is  suf- 
ficient for  the  cure.     They  would  even  divide  its  other  tendons,  if  the  parallelism  be  not 
restored,  rather  than  touch  the  other  eye.     The  Author  is  himself  satisfied,  however,  that 
the  restriction  of  the  abnormal  state  to  a  single  eye,  is  the  exception,  and  not  the  rule,  in 
all  but  very  slight  cases  of  Strabismus ;  and  to  this  opinion  he  is  led,  both  by  the  conside- 
ration of  the  mode  in  which  strabismus  first  takes-place,  and  by  the  results  of  the  opera- 
tions which  have  come  under  his  notice.     If  the  eyes  of  an  infant  affected  with  cerebral 
disease  be  watched,  there  will  frequently  be  observed  in  them  very  irregular  movements ; 
the  axes  of  the  two  being  sometimes  extremely  convergent,  and  then  very  divergent. 
This  irregularity  is  rarely  or  never  seen  to  be  confined  to  one  eye.     Now,  in  a  large  pro- 
portion of  cases  of  Strabismus,  the  malady  is  a  consequence  of  some  cerebral   affection 
during  infancy  or  childhood,  which  we  can  scarcely  suppose  to  have  affected  one  eye  only. 
Again,  in  other  instances  we  find  the  Strabismus  to  have  resulted  from  the  constant  direc- 
tion of  the  eyes  to  very  near  objects,  as  in  short-sighted  persons;  and  here,  too,  the  cause 
manifestly  affects  both. — Now  it  is  easy  to  understand  why  one  eye  of  the  patient  should 
appear  to  be  in  its  natural  position,  whilst  the  other  is  greatly  inverted.     The  cause  of 
Strabismus  usually  affects  the  two  eyes  somewhat  unequally,  so  that  one  is  much  more 
inverted  than  the  other.     We  will  call  the  least  inverted  eye  A,  and  the  other  B.     In  the 
ordinary  acts  of  vision,  the  patient  will  make  most  use  of  the  least  inverted  eye,  A,  be- 
cause he  can  most  readily  look  straight-forwards  or  outwards  with  it ;  but  to  bring  it  into 
the  axis,  or  to  rotate  it  outwards,  necessitates  a  still  more  decided  inversion  of  B.     This 
remains  the  position  of  things, — the  patient  usually  looking  straight  forwards  with  A, 
which  is  the  eye  constantly  employed  for  the  purposes  of  vision, — and  frequently  almost 
burying  the  other  eye  B,  the  vision  in  which  is  of  very  little  use  to  him,  under  the  inner 
canthus.     When,  therefore,  the  tendon  of  the  internal  rectus  of  B  is  divided,  the  relative 
position  of  the  two  is  not  entirely  rectified.     Sometimes  it  appears  to  be  so  for  a  time ;  but 
the  strabismus  then  begins  to  return,  and  it  can  only  be  checked  by  division  of  the  tendon 
of  the  other  eye,  A  ;  after  which,  the  cure  is  generally  complete  and  permanent.     That  it 
has  not  been  so  in  many  of  the  patients  on  whom  operations  have  been  performed,  the 
Author  attributes,  without   the  slightest  doubt  in  his  own   mind,  to  the  neglect  of  the 
second  operation.     As  just  now  stated,  the  sight  of  the  most  inverted  eye  is  frequently 
very  imperfect ;  indeed  it  is  sometimes  impaired  to  such  an  extent,  that  the  patients  speak 
of  it  as  entirely  useless.     That  this  impairment  results  in  part  from  disuse  merely,  seems 
very  evident,  from  the  great  improvement  which  often  succeeds  the  rectification  of  the 
axes. — A  valuable  memoir  by  Prof.  Pancoast,  on  the  'Operation  for  Strabismus,'  founded 
on  the  results  of  about  1000  cases,  will  be  found  in  the  "  Philadelphia  Medical  Examiner," 
vol.  vii  ,  and  an  abstract  of  it  in  the  "Brit,  and  For.  Med.-Chir.  Review,"  July,  1852, 
p.  262. 


ENERGY   AND    RAPIDITY    OF    MUSCULAR    CONTRACTION.  715 

for  example,  with  persons  who  have  gained  their  livelihood  by  exhibiting  feats 
of  strength.  Much  will,  of  course,  depend  on  the  mechanically-advantageous 
application  of  muscular  power;  and  in  this  manner,  effects  may  be  produced, 
even  by  persons  of  ordinary  strength,  which  would  not  have  been  thought  credi- 
ble. In  lifting  a  heavy  weight  in  each  hand,  for  example,  a  person  who  keeps 
his  back  perfectly  rigid,  so  as  to  throw  the  pressure  vertically  upon  the  pelvis, 
and  only  uses  the  powerful  extensors  of  the  thigh  and  calf,  by  straightening  the 
knees  (previously  somewhat  flexed),  and  bringing  the  leg  to  a  right  angle  with 
the  foot,  will  have  a  great  advantage  over  one  who  uses  his  lumbar  muscles  for 
the  purpose.  A  still  greater  advantage  will  be  gained  by  throwing  the  weight 
more  directly  upon  the?  loins,  by  means  of  a  sort  of  girdle,  shaped  so  as  to  rest 
upon  the  top  of  the  sacrum  and  the  ridges  of  the  ilia ;  and  by  pressing  with  the 
hand  upon  a  frame,  so  arranged  as  to  bring  the  muscles  of  the  arms  to  the  assist- 
ance of  those  of  the  legs  :  in  this  manner,  a  single  Man  of  ordinary  strength  may 
raise  a  weight  of  2000  Ibs. ;  whilst  few  who  are  unaccustomed  to  such  exertions, 
can  lift  more  than  300  Ibs.  in  the  ordinary  mode.  A  man  of  great  natura. 
strength,  however,  has  been  known  to  lift  800  Ibs.  with  his  hands ;  and  the  same 
individual  performed  several  other  curious  feats  of  strength,  which  seem  deserv- 
ing of  being  here  noticed.  "  1.  By  the  strength  of  his  fingers,  he  rolled-up  a 
very  large  and  strong  pewter  dish.  2.  He  broke  several  short  and  strong  pieces 
of  tobacco-pipe,  with  the  force  of  his  middle-finger,  having  laid  them  on  the  first 
and  third  finger.  3.  Having  thrust-in  under  his  garter  the  bowl  of  a  strong 
tobacco-pipe,  his  legs  being  bent,  he  broke  it  to  pieces  by  the  tendons  of  his  hams, 
without  altering  the  bending  of  the  knee.  4.  He  broke  such  another  bowl  be- 
tween his  first  and  second  fingers,  by  pressing  them  together  sideways.  5.  He 
lifted  a  table  six  feet  long,  which  had  half  a  hundred-weight  hanging  at  the  end 
of  it,  with  his  teeth,  and  held  it  in  that  position  for  a  considerable  time.  It  is 
true,  the  feet  of  the  table  rested  against  his  knees  ;  but  as  the  length  of  the  table 
was  much  greater  than  its  height,  that  performance  required  a  great  strength  to 
be  exerted  by  the  muscles  of  his  loins,  neck,  and  jaws.  6.  He  took  an  iron 
kitchen  poker,  about  a  yard  long,  and  three  inches  in  circumference,  and  holding 
it  in  his  right  hand,  he  struck  it  on  his  bare  left  arm,  between  the  elbow  and  the 
wrist,  till  he  bent  the  poker  nearly  to  a  right  angle.  7.  He  took  such  another 
poker,  and,  holding  the  ends  of  it  in  his  hands,  and  the  middle  of  it  against  the 
back  of  his  neck,  he  brought  both  ends  of  it  together  before  him  ;  and,  what  was 
yet  more  difficult,  he  pulled  it  straight  again."1  Haller  mentions  an  instance  of 
a  man,  who  could  raise  a  weight  of  300  Ibs.,  by  the  action  of  the  elevator  mus- 
cles of  his  jaw  ;  and  that  of  a  slender  girl,  affected  with  tetanic  spasm,  in  whom 
the  extensor  muscles  of  the  back,  in  the  state  of  tonic  contraction  or  opisthotonos, 
resisted  a  weight  of  800  Ibs.,  laid  on  the  abdomen,  with  the  absurd  intention  of 
straightening  the  body. — It  is  to  be  recollected,  that  the  mechanical  application 
of  the  power  developed  by  muscular  contraction,  to  the  movement  of  the  body,  is 
very  commonly  disadvantageous  as  regards /orce;  being  designed  to  cause  the 
part  moved  to  pass  over  a  much  greater  space  than  that  through  which  the  muscle 
contracts.  Thus  the  temporal  muscle  is  attached  to  the  lower  jaw;  at  about 
one-third  of  the  distance  between  the  condyle  and  the  incisors;  so  that  a  shorten- 
ing of  the  muscle  to  the  amount  of  half  an  inch,  will  draw-up  the  front  of  the 
jaw  through  an  inch  and  a  half;  but  a  power  of  900  Ibs.,  applied  by  the  muscle, 
would  be  required  to  raise  300  Ibs.  bearing  on  the  incisors.  In  the  case  of  the 
fore-arm  and  leg,  the  disproportion  is  much  greater;  the  points  of  attachment 
of  the  muscles,  by  which  the  knee  and  elbow-joints  are  flexed  and  extended, 
being  much  closer  to  the  fulcrum,  in  comparison  with  the  distance  of  the  points 
on  which  the  resistance  bears. 

b02.  The  rapidity  of  the  changes  of  position  of  the  component  particles  of 
muscular  fibres  may,  as  Dr.  Alison  justly  remarks,2  be  estimated,  though  it  can 

*  "  Desaguliers'  Philosophy,"  vol.  ii. 

a  "  Cyclopaedia  of  Anatomy  and  Physiology,"  Art.  "  Contractility.' 


716  OF    MUSCULAR    MOVEMENTS. 

hardly  be  conceived,  from  various  well-known  facts.  The  pulsations  of  the  heart 
can  sometimes  be  distinctly  numbered  in  children,  at  more  than  200  in  the 
minute  ;  and  as  such  contraction  of  the  ventricles  occupies  only  half  the  time  of 
the  whole  pulsation,  it  must  be  accomplished  in  l-400th  of  a  minute,  or  3-20ths 
of  a  second.  Again,  it  is  certain  that,  by  the  movements  of  the  tongue  and 
other  organs  of  speech,  1500  letters  can  be  distinctly  pronounced  by  some  persons 
in  a  minute :  every  one  of  these  must  require  a  separate  contraction  of  muscular 
fibres;  and  the  production  and  cessation  of  each  of  the  sounds,  implies  that  each 
separate  contraction  must  be  followed  by  a  relaxation  of  equal  length ;  each  con- 
traction, therefore,  must  have  been  effected  in  l-3000th  part  of  a  minute,  or  in 
l-50th  of  a  second.  Haller  calculated  that,  in  the  limbs  of  a  dog  at  full  speed, 
muscular  contractions  must  take  place  in  less  than  the  l-200th  of  a  second,  for 
many  minutes  at  least  in  succession. — All  these  instances,  however,  are  thrown 
into  the  shade  by  those  which  may  be  drawn  from  the  class  of  Insects.  The 
rapidity  of  the  vibrations  of  the  wings  may  be  estimated  from  the  musical  tone 
which  they  produce;  it  being  easily  ascertained  by  experiments,  what  number 
of  vibrations  are  required  to  produce  any  note  in  the  scale  (§  787).  From  these 
data,  it  appears  to  be  the  necessary  result,  that  the  wings  of  many  Insects  strike 
the  air  many  hundred  or  even  many  thousand  times  in  every  second. — The 
minute  precision  with  which  the  degree  of  muscular  contraction  can  be  adapted 
to  the  designed  effect,  is  in  no  instance  more  remarkable  than  in  the  Glottis. 
The  musical  pitch  of  the  tones  produced  by  it,  is  regulated  by  the  degree  of 
tension  of  the  chordae  vocales,  which  are  possessed  of  a  very  considerable  degree 
of  elasticity  (§  805).  According  to  the  observations  of  Miiller,1  the  average 
length  of  these,  in  the  male,  in  a  state  of  repose,  is  about  73-100ths  of  an  inch; 
whilst,  in  the  state  of  greatest  tension  it  is  about  93-100ths;  the  difference  being 
therefore  20-100ths,  or  one-fifth  of  an  inch;  in  the  female  glottis,  the  average 
dimensions  are  about  51-100ths,  and  63-100ths  respectively;  the  difference  being 
thus  about  one-eighth  of  an  inch.  Now  the  natural  compass  of  the  voice,  in  most 
persons  who  have  cultivated  the  vocal  organs,  may  be  stated  at  about  two  octaves, 
or  24  semitones.  Within  each  semitone,  a  singer  of  ordinary  capability  could 
produce  at  least  ten  distinct  intervals;  so  that  of  the  total  number,  240  is  a  very 
moderate  estimate.  There  must,  therefore,  be  at  least  240  different  states  of  ten- 
sion of  the  Vocal  Cords,  every  one  of  which  is  producible  by  the  will,  without  any 
previous  trial;  and  the  whole  variation  in  the  length  of  the  cords  being  not  more 
than  one-fifth  of  an  inch,  even  in  man,  the  variation  required  to  pass  from  one 
interval  to  another,  will  not  be  more  than  l-1200th  of  an  inch.  And  yet  this 
estimate  is  much  below  that,  which  might  be  truly  made  from  the  performances 
of  a  practised  vocalist.2 

[It  has  been  thought  by  the  Author,  that  it  would  be  scarcely  accordant  with  the  plan 
of  this  work,  and  that  it  would  add  needlessly  to  its  bulk,  if  he  were  to  enter  into  that 
minute  analysis  of  the  various  groups  of  Muscular  actions  concerned  in  standing,  sitting, 
walking,  running,  swimming,  &c.,  which  some  writers  have  thought  to  form  an  essential 
part  of  a  Physiological  Treatise.  Such  an  analysis  as  it  appears  to  him,  leads  to  no  prac- 
tically-important result ;  and  the  actions  of  individual  muscles,  into  which  these  composite 
groups  are  thus  resolved,  must  after  all,  be  separately  studied  in  connection  with  their 
respective  attachments  and  directions  of  traction.  The  subject  of  the  locomotion  of  Man 
has  been  particularly  investigated  by  the  Profrs.  Weber,  whose  work  entitled  "  Mechanik 
dor  menslich  Gehewerzenge,"  (Gottingen,  1836)  has  been  translated  in  Jourdain's  "Ency- 
clopedic Anatomique,"  torn.  ii.  See  also  the  Art.  'Motion'  by  Mr.  J.  Bishop,  in  "Cy- 
clop, of  Anat.  and  Physiol.,"  vol.  iii.] 


1  "  Elements  of  Physiology,"  Baly's  translation,  p.  1018. 

•  It  is  said  that  the  celebrated  Madame  Mara  was  able  to  sound  100  different  intervals 
between  each  tone.  The  compass  of  her  voice  was  at  least  three  octaves,  or  21  tones ;  sc 
that  the  total  number  of  intervals  was  2100,  all  comprised  within  an  extreme  variation  of 
one-eighth  of  an  inch  ;  so  that  it  might  be  said  that  she  was  able  to  determine  the  contrac- 
tions of  her  vocal  muscles  to  nearly  the  seventeen-thousandth  of  an  inch. 


OF    THE    LARYNX,    AND    ITS    ACTIONS.  717 

CHAPTER  XIV. 

OF    THE    VOICE    AND    SPEECH. 
1. —  Of  the  Larynx,  and  its  Actions. 

803.  THE  sounds  produced  by  the  organ  of  Voice  constitute  the  most  important 
means  of  communication  between  Man  and  his  fellows  (§  613) ;  and  the  power 
of  Speech  has,  therefore,  a  primary  influence,  as  well  on  his  physical  condition, 
as  on  the  development  of  his  mental  faculties.     It  is  necessary  to  bear  in  mind, 
that  Vocal  sounds,  and  Speech  or  articulate  Language,  are  two  things  entirely 
different;  and  that  the  former  may  be  produced  in  great  perfection,  where  there 
is  no  capability  for  the  latter.     Hence  we  might  at  once  infer,  that  the  instru- 
ment for  the  production  of  vocal  sounds  is  distinct  from  that  by  which  these 
sounds  are  modified  into  articulate  speech;  and  this  we  easily  discover  to  be  the 
case,  the  voice  being  unquestionably  produced  in  the  larynx,  whilst  the  modifica- 
tions of  it  by  which  language  is  formed,  are  effected  for  the  most  part  in  the  oral 
cavity. — The  structure  and  functions  of  the  former,  then,  first  claim  our  attention. 

804.  It  will  be  remembered  that  the  Trachea  is  surmounted  by  a  stout  carti- 
laginous annulus,  termed  the  Oricoid  cartilage  (Figs.  187,  188,  A  B,  and  Fig.  189, 
r  u  x  w}',  which  serves  as  a  foundation  for  the  superjacent  mechanism.     This  is 
embraced  (as  it  were)  by  the   Thyroid  (Fig.   187,  E  c  G,  Fig.   188,  G  E  H), 
which  is  articulated  to  its  sides  by  the  lower  horns  (Figs.  187,  188,  c),  round  the 


Median  Section  of  Mouth,  Nose,  Pharynx,  and  Larynx : — a,  septum  of  nose ;  below  it,  sec- 
tion of  hard  palate;  6,  tongue;  c,  section  of  velum  pendulum  palati;  d,  d,  lips;  «,  uvula;  r, 
anterior  arch  or  pillar  of  fauces;  t,  posterior  arch;  t,  tonsil;  p,  pharynx;  h,  hyoid  bone: 
k,  thyroid  cartilage ;  n,  crycoid  cartilage ;  *.  epiglottis ;  v,  glottis ;  1,  posterior  opening  of 
nares ;  3,  isthmus  faucium ;  4,  superior  opening  of  larynx ;  5,  passage  into  (Esophagus ;  6, 
mouth  of  right  Eustachian  tube. 


718 


OF    THE    VOICE    AND    SPEECH. 
FIG.  187.  FIG.  188. 


FIG.  189. 


External  and  Sectional  views  of  the  Larynx; — A  n  B,  the  cricoid  cartilage;  E  c  G,  the  thy- 
roid cartilage;  G,  its  upper  horn;  c,  its  lower  horn,  where  it  is  articulated  with  the  cricoid; 
r,  the  arytenoid  cartilage;  E  p,  the  vocal  ligament;  A  K,  crico-thyroideus  muscle;  pent, 
thyro-arytenoideus  muscle;  x  e,  crico-arytenoideus  lateralis ;  *,  transverse  section  of  aryte- 
noideus  transversus  ;  m  n,  space  between  thyroid  and  cricoid;  B  L,  projection  of  axis  of  arti- 
culation of  arytenoid  with  thyroid. 

extremities  of  which  it  may  be  regarded  as 
turning,  as  on  a  pivot.  In  this  manner,  the 
lower  front  border  of  the  Thyroid  cartilage, 
which  is  ordinarily  separated  by  a  small  in- 
terval (Figs.  187,  188,  m  n)  from  the  up- 
per margin  of  the  Cricoid,  may  be  made  to 
approach  it  or  to  recede  from  it  ]  as  any  one 
may  easily  ascertain,  by  placing  his  finger 
against  the  little  depression  which  may  be 
readily  felt  externally,  and  observing  its 
changes  of  size,  whilst  a  range  of  different 
tones  is  sounded ;  for  it  will  then  be  noticed 
that,  the  higher  the  note,  the  more  the  two 
cartilages  are  made  to  approximate,  whilst 
they  separate  in  proportion  to  the  depth  of 
the  tones.1  Upon  the  upper  surface  of  the 
back  of  the  Cricoid,  are  seated  the  two  small 
Arytenoid  cartilages  (Figs.  186,  188,  r  F); 
these  are  fixed  in  one  direction  by  a  bundle 
of  strong  ligaments,  which  tie  them  to  the 
back  of  the  cricoid;  but  they  have  some 
power  of  moving  in  other  directions,  upon  a 
kind  of  articulating  surface.  The  direction 
of  the  surface,  and  the  mode  in  which  these 
cartilages  are  otherwise  attached,  cause  their 
movement  to  be  a  sort  of  rotation  in  a  plane, 
which  is  nearly  horizontal  but  partly  down- 
wards ]  so  that  their  vertical  planes  may  be 
made  to  separate  from  each  other,  and  at 
the  same  time  to  assume  a  slanting  position. 

'  In  making  this  observation,  it  is  necessary  to  put  out  of  view  the  general  movement 
of  the  Larynx  itself,  which  the  finger  must  be  made  to  follow  up  and  down- 


Bird's-eye  view  of  Larynx  from  above : 
— G  E  H,  the  thyroid  cartilage,  embracing 
the  ring  of  the  cricoid  r  u  x  w,  and  turning 
upon  the  axis  x  z,  which  passes  through 
the  lower  horns,  c,  Fig.  186 ;  N  p,  N  F,  the 
arytenoid  cartilages,  connected  by  the  ary- 
tenoideus  transversus ;  T  v,  T  v,  the  vocal 
ligaments;  N  x,  the  right  crico-arytenoi- 
deus lateralis  (the  left  being  removed ;  v  k 
f,  the  left  thyro-arytenoideus  (the  right 
being  removed) ;  N  I,  N  I,  the  crico-aryte- 
noidei  postici;  B  B,  the  crico-arytenoid  lig- 
aments. 


OF    THE    LARYNX,    AND    ITS    ACTIONS.  719 

This  change  of  place  will  be  better  understood,  when  the  action  of  the  muscles 
is  described.  To  the  summit  of  the  Arytenoid  cartilages  are  attached  the  chordae 
vocales  or  Vocal  Ligaments  (Fig.  186,  E  F,  Fig.  188,  T  v),  which  stretch -across 
to  the  front  of  the  Thyroid  cartilage;  and  it  is  upon  the  condition  and  relative 
situation  of  these  ligaments,  that  their  action  depends.  It  is  evident  that  they 
may  be  rendered  more  or  less  tense,  by  the  movement  of  the  Thyroid  cartilage 
just  described;  being  tightened  by  the  depression  of  its  front  upon  the  Cricoid 
cartilage,  and  slackened  by  its  elevation.  On  the  other  hand,  they  may  be 
brought  into  more  or  less  close  apposition,  by  the  movement  of  the  Arytenoid 
cartilages ;  being  made  to  approximate  nearly,  or  to  recede  in  such  a  manner  as 
to  cause  the  rima  glottidis  to  assume  the  form  of  a  narrow  V,  by  the  revolution 
of  these  cartilages. — We  shall  now  inquire  into  the  actions  of  the  muscles  upon 
the  several  parts  of  this  apparatus;  and  first  into  those  of  the  larynx  alone. 

805.  The  depression  of  the  front  of  the  Thyroid  cartilage,  and  the  consequent 
tension  of  the  Vocal  Ligaments,  is  occasioned  by  the  conjoint  action  of  the  Crico- 
thyroidei  (Fig.  188,  A  K)  on  both  sides;  and  the  chief  antagonists  to  these  are 
the  Thyro-arytenoidei  (Fin:.  187,  F  m,  Fig.  189,  V  &/),  which  draw  the  front 
of  the  thyroid  back  towards  the  arytenoid  cartilages,  and  thus  relax  the  vocal 
ligaments.  These  two  pairs  of  muscles  may  be  regarded  as  the  principal  governors 
of  the  pitch  of  the  notes,  which,  as  we  shall  hereafter  see,  is  almost  entirely  regu- 
lated by  the  tension  of  the  ligaments ;  their  action  is  assisted,  however,  by  that 
of  other  muscles  presently  to  be  mentioned. — The  arytenoid  cartilages  are  made 
to  diverge  from  each  other,  by  means  of  the  Crico-arytenoidei  postici  (Fig.  189, 

FIG.  190. 


YJ 

Part  of  Fig.  188  enlarged,  to  show  the  Direction  of  the  Muscular  Forces  which  act  on  the 
Arytenoid  cartilage: — N  v  s,  the  right  Arytenoid  cartilage;  T  v,  its  vocal  ligament;  B  R  s, 
bundle  of  ligaments  uniting  it  to  Cricoid ;  o  P,  projection  of  its  axis  of  articulation;  h  g,  direc- 
tion of  the  action  of  the  Thyro-arytenoideus ;  N  x,  direction  of  Crico-arytenoideus  lateralis ; 
N  w,  direction  of  Crico-arytenoideus  posticus;  N  Y,  direction  of  Arytenoideus  transversus. 

N  Z)  of  the  two  sides,  which  proceed  from  their  outer  corners,  and  turn  somewhai 
round  the  edge  of  the  Cricoid,  to  be  attached  to  the  lower  part  of  its  back ;  their 
action  is  to  draw  the  outer  corners  backwards  and  downwards,  so  that  the  points 
to  which  the  vocal  ligaments  are  attached  are  separated  from  one  another,  and  the 
rima  glottidis  is  thrown  open.  This  will  be  at  once  seen  from  the  preceding  dia- 
gram, in  which  the  direction  of  traction  of  the  several  muscles  is  laid-down. — The 
action  of  these  muscles  is  partly  antagonised  by  that  of  the  Crico-arytenoidei  late- 
rales  (Fig.  189,  N  x),  which  run  forwards  and  downwards  from  the  outer  corners 
of  the  Arytenoid  cartilages,  and  whose  contraction  tends  to  bring  their  auterioi 


720  OF    THE    VOICE    AND     SPEECH. 

points  into  the  same  straight  line,  depressing  them  at  the  same  time,  so  as  thus 
to  close,  the  glottis.  These  muscles  are  assisted  by  the  Arytenoideus  transversus 
('Fig.  189),  which  connects  the  posterior  faces  of  the  Arytenoid  cartilages,  and 
which,  by  its  contraction,  draws  them  together.  By  the  conjoint  action,  there- 
fore, of  the  Crico-arytenoidei  laterales  and  of  the  Arytenoideus  transversus,  the 
whole  of  the  adjacent  faces  of  the  Arytenoid  cartilages  will  be  approximated,  and 
the  points  to  which  the  vocal  ligaments  are  attached  will  be  depressed. — But  if 
the  Arytenoideus  be  put  in  action  in  conjunction  with  the  Crico-arytenoidei  pos- 
tici,  the  tendency  of  the  latter  to  separate  the  Arytenoid  cartilages  being  antago- 
nised by  the  former,  its  backward  action  only  will  be  exerted  ;  and  thus  it  may  be 
caused  to  aid  the  Crieo-thyroidei  in  rendering  tense  the  vocal  ligaments.  This 
action  will  be  further  assisted  by  the  Stcrno-thyroidei,  which  tend  to  depress  the 
Thyroid  cartilage,  by  pulling  from  a  fixed  point  below;1  and  the  Thyro-hyoidei 
will  be  the  antagonist  of  these,  when  they  act  from  a  fixed  point  above,  the  Os 
Hyoidvs  being  secured  by  the  opposing  contraction  of  several  other  muscles. — The 
respective  actions  of  these  muscles  will  be  best  comprehended  by  the  following 
Table. 

Govern  the  pitch  of  the  notes. 

_  f  Depress  the  front  of  the  Thyroid  cartilage  on  the 

pi  J  QRI<         ™     '  > -I      Cricoid,  aad  stretch  the  vocal  ligaments;  assisted 

|j-  (  STERNO-IHYROIDEI  ^      ^y  the  Arytenoideus  and  Crico-arytenoidei  postici. 

(  Elevate  the  front  of  the  Thyroid  cartilage,  and  draw 

g.  I  THYRO-ARYTENOIDEI      1  1      .          ^  the  Arytenoids,  relaxing  the  vocal  liga- 

&  )  THYRO-HYOIDEI  /  j     mentg 

Govern  the  Aperture  of  the  Glottis. 
>    CRICO-ARYTENOIDEI  POSTICI Oven  the  Glottis. 

£3 

g.  f  CRICO-ARYTENOIDEI  LATERALES  "i  f  Press  together  the  inner  edges  of  the  Ary- 

S-  \  ARYTENOIDEUS  TRANSVERSUS      J  "       "\     tenoid  cartilages,  and  close  the  Glottis. 

806.  The  muscles  which  stretch  or  relax  the  Vocal  ligaments,  are  entirely 
concerned  in  the  production  of  Voice;  those  which  govern  the  aperture  of  the 
Glottis  have  important  functions  in  connection  with  the  Respiratory  actions  in 
general,  and  stand  as  guards  (so  to  speak)  at  the  entrance  to  the  lungs.  These 
separate  actions  are  easily  made  evident.  In  the  ordinary  condition  of  rest,  it 
seems  probable  that  the  Arytenoid  cartilages  are  considerably  separated  from 
each  other;  so  as  to  cause  a  wide  opening  to  intervene  between  their  inner  faces, 
and  between  the  vocal  ligaments,  through  which  the  air  freely  passes ;  and  the 
vocal  ligaments  are  at  the  same  time  in  a  state  of  complete  relaxation. — We  can 
close  the  aperture  of  the  Glottis  by  an  exertion  of  the  will,  during  either  inspira- 
tion or  expiration;  and  its  closure  by  an  automatic  impulse  forms  part  of  the  acts 
of  Coughing  and  Sneezing  (§  306),  besides  giving-rise  to  those  more  prolonged 
impediments  to  the  ingress  and  egress  of  air,  which  have  been  already  noticed  as 
resulting  from  disordered  states  of  the  Nervous  system  (§§  720,  724).  With 
these  actions,  the  muscles  which  regulate  the  tension  of  the  vocal  ligaments  have 
nothing  to  do;  and  we  have  seen  that  they  are  performed  by  the  instrumentality 
of  the  Pneumogastric  or  proper  Respiratory  nerve  (§§  303,  304).  A  slight  exami- 
nation of  the  recent  Larynx  is  sufficient  to  make  it  evident,  that,  when  once  the 
borders  of  the  rima  glottidis  are  brought-together  by  muscular  action,  the  effect 
of  strong  aerial  pressure  on  either  side  (whether  produced  by  an  expulsory  blast 
from  below,  or  by  a  strong  inspiratory  effort,  occasioning  a  partial  vacuum  below, 
and  consequently  an  increased  pressure  above),  will  be  to  force  them  into  closer 

1  These  are  not  usually  reckoned  among  the  principal  muscles  concerned  in  regulating 
the  voice ;  but  that  they  are  so,  any  one  may  convince  himself  by  placing  his  finger  just 
above  the  sternum,  whilst  he  is  sounding  high  notes;  a  strong  feeling  of  muscular  tension 
is  then  at  once  perceived. 


OF    THE    LARYNX,    AND     ITS    ACTIONS  721 

apposition. — In  order  to  produce  a  Vocal  sound,  it  is  not  sufficient  to  put  the 
ligaments  into  a  state  of  tension;  they  must  also  be  brought  nearer  to  each  other. 
That  the  aperture  of  the  glottis  is  greatly  narrowed  during  the  production  of 
sounds,  is  easily  made  evident  to  one's-self,  by  comparing  the  time  occupied  by  an 
ordinary  expiration,  with  that  required  for  the  passage  of  the  same  quantity  of  air 
during  the  sustenance  of  a  vocal  tone.  Further,  the  size  of  the  aperture  is  made 
to  vary  in  accordance  with  the  note  which  is  being  produced  ;  of  this,  too,  any 
one  may  convince  himself,  by  comparing  the  times  during  which  he  can  hold-out 
a  low  and  a  high  note  :  from  which  it  will  appear,  that  the  aperture  of  the  glottis 
is  so  much  narrowed  in  producing  a  high  note,  as  to  permit  a  far  less  rapid  pas- 
sage of  air  than  is  allowed  when  a  low  one  is  sounded.  This  adjustment  of  the 
aperture  to  the  tension  of  the  vocal  ligaments,  is  a  necessary  condition  for  the 
production  of  a  clear  and  definite  tone.  It  further  appears  that,  in  the  narrowing 
of  the  glottis  which  is  requisite  to  bring  the  vocal  ligaments  into  the  necessary 
approximation,  the  upper  points  of  the  Arytenoid  cartilages  are  caused  to  approxi- 
mate, not  only  by  being  made  to  rotate  horizontally  towards  each  other,  but  also 
by  a  degree  of  elevation ;  so  that  the  inner  faces  of  the  vocal  ligaments  are 
brought  into  parallelism  with  each  other, — a  condition  which  may  be  experimen- 
tally shown  to  be  necessary  for  their  being  thrown  into  sonorous  vibration  (§810). 
The  muscular  movements  concerned  in  the  act  of  vocalization,  appear  to  be  called- 
forth  by  the  instrumentality  of  the  fibres  of  the  Spinal  Accessory  nerve  which  are 
contained  in  the  Pneumogastric  (§  498). 

807.  We  have  now  to  inquire  what  is  the  operation  of  the  Vocal  Ligaments  in 
the  production  of  sounds ;  and  in  order  to  comprehend  this,  it  s  necessary  to 
advert  to  the  conditions  under  which  tones  are  produced  by  instruments  of  various 
descriptions  having  some  analogy  with  the  Larynx.  These  are  chiefly  of  three 
kinds ;  strings,  flute-pipes,  and  reeds  or  tongues. — The  Vocal  Ligaments  were 
long  ago  compared  by  Ferrein  to  vibrating  strings;  and  at  first  sight  there  might 
Boem  a  considerable  analogy,  the  sounds  which  both  produce  being  elevated  by 
increased  tension.  This  resemblance  disappears,  however,  on  more  accurate 
comparison ;  for  it  may  be  easily  ascertained  by  experiment,  that  no  string  so 
short  as  the  vocal  ligaments  could  give  a  clear  tone,  at  all  to  be  compared  in  depth 
with  that  of  the  lowest  notes  of  the  human  voice;  and  also,  th^t  the  scale  of 
changes  produced  by  increased  tension  is  fundamentally  different.  When-  strings 
of  the  same  length,  but  of  different  tensions,  are  made  the  subject  of  comparison, 
it  is  found  that  the  number  of  vibrations  is  in  proportion  to  the  square-roots  of 
the  extending  forces.  Thus,  if  a  string  extended  by  a  given  weight  produce  a 
certain  note,  a  string  extended  by  four  times  that  weight  will  give  a  note  in 
which  the  vibrations  are  twice  as  rapid;  and  this  will  be  the  octave  of  tlie  other. 
If  nine  times  the  original  weight  be  employed,  the  vibrations  will  be  three  times 
as  rapid  as  those  of  the  fundamental  note,  producing  the  twelfth  above  it.  Now 
by  fixing  the  larynx  in  such  a  manner  that  the  vocal  ligaments  can  be  extended 
by  a  known  weight,  Miiller  has  ascertained  that  the  sounds  produced  by  a  varia- 
tion of  the  extending  force  do  not  follow  the  same  ratio ;  and  therefore  the  con- 
dition of  these  ligaments  cannot  be  simply  that  of  vibrating  cords.  Further, 
although  a  cord  of  a  certain  length,  which  is  adapted  to  give-out  a  clear  and  dis- 
tinct note,  equal  in  depth  to  the  lowest  of  the  human  voice,  may  be  made  by  in- 
creased tension  to  produce  all  the  superior  notes  (which,  in  stringed  instruments, 
are  ordinarily  obtained  by  shortening  the  strings),  it  does  not  follow  that  a  short 
string,  which,  with  moderate  tension,  naturally  produces  a  high  note,  should  be 
able,  by  a  diminution  of  the  tension,  to  give-out  a  deep  one;  for,  although  this 
might  be  theoretically  possible,  yet  it  cannot  be  accomplished  in  practice;  since 
the  vibrations  become  irregular  on  account  of  the  diminished  elasticity.1  These 

1  Thus  it  would  be  impossible  to  produce  good  Bass  notes  on  the  strings  of  a  Violin,  by 
diminishing  their  tension ;  the  length  afforded  by  the  Violincella  or  Double-  Bass  is  re- 
quisite. 

46 


722  OF    THE    VOICE    AND    SPEECH. 

considerations  are  in  themselves  sufficient  to  destroy  the  supposed  analogy;  ami 
to  prove  that  the  Chordae  Vocales  cannot  be  reduced  to  the  same  category  with 
vibrating  strings. 

808.  The  next  kind  of  instrument  with  which  some  analogy  might  be  sus- 
pected, is  the  flute-pipe,  in  which  the  sound  is  produced  by  the  vibration  of  an 
elastic  column  of  air  contained  in  the  tube ;  and  the  pitch  of  the  note  is  deter- 
mined almost  entirely  by  the  length  of  the  column,  although  slightly  modified  by 
its  diameter,  and  by  the  nature  of  the  embouchure  or  mouth  from  which  it  issues. 
This  is  exemplified  in  the  German  Flute,  and  in  the  English  Flute  or  Flageolet ; 
in  both  of  which  instruments,  the  acting  length  of  the  pipe  is  determined  by  the 
interval  between  the  embouchure  and  the  nearest  of  the  side-apertures ;  by  open- 
ing or  closing  which,  therefore,  a  modification  of  the  tone  is  produced.     In  the 
Organ,  of  which  the  greater  number  of  pipes  are  constructed  upon   this  plan, 
there  is  a  distinct  pipe  for  every  note;  and  their  length  increases  in  a  regular 
scale.     It  is,  in   fact,  with  flute-pipes  as  with  strings, — that  a  diminution  in 
length  causes  an  increase  in  the  number  of  vibrations,  in  a  simply-inverse  propor- 
tion ;  so  that  of  two  pipes,  one  being  half  the  length  of  the  other,  the  shorter 
will  give  a  tone  which  is  the  octave  above  the  other,  the  vibrations  of  its  column 
of  air  being  twice  as  rapid.     Now,  there  is  nothing  in  the  form  or  dimensions  of 
the  column  of  air  between  the  larynx  and  the  mouth,  which  can  be  conceived  to 
render  it  at  all  capable  of  such  vibrations  as  are  required  to  produce  the  tones  of 
the  Human  voice ;  though  there  is  some  doubt,  whether  it  be  not  the  agent  in 
the  musical  tones  of  certain  Birds.     The  length  that  would  be  required  in  an 
open  pipe  to  give  the  lowest  G  of  the  ordinary  bass  voice,  is  nearly  six  feet ;  and 
the  conditions  necessary  to  produce  the  higher  notes  from  it,  are  by  no  means 
those  which  we  find  to  exist  in  the  process  of  modulating  the  human  voice. 

809.  We  now  come  to  the  third  class  of  instruments,  in  which  sound  is  pro- 
duced by  the  vibration  of  reeds  or  tongues  ;  these  may  either  possess  elasticity  in 
themselves,  or  be  made  elastic  by  tension.     The  'free'  reeds  of  the  Accordeon, 
Concertina,  Seraphine,  Harmonium,  &c.,  are  examples  of  instruments  of  this 
character,  in  which  the  lamina  vibrates  in  a  sort  of  frame  that  allows  the  air  to 
pass-out  on  all  sides  of  it  through  a  narrow  channel,  thus  increasing  the  strength 
of  the  blast;  whilst  in   the  Hautboy,  Bassoon,  &c.,  and  in  the  Organ-pipes  of 
similar  construction,  the  reed  covers  an  aperture  at  the  side  of  one  end  of  a  pipe. 
In  the  former  kind,  the  sound  is  produced  by  the  vibration  of  the  tongue  alone, 
and  is  regulated  entirely  by  its  length  and  elasticity ;  whilst  in  the  latter,  its 
pitch  is  dependent  upon  this,  conjointly  with  the  length  of  the  tube,  the  column 
of  air  contained  in  which  is  thrown  into  simultaneous  vibration.     Some  interest- 
ing researches  on  the  effect  produced  on  the  pitch  of  a  sound  given  by  a  reed 
through  the  union  of  it  with  a  tube,  have  been  made  by  M.  W.  Weber ;  and,  as 
they  are  important  in  furnishing  data  by  which  the  real  nature  of  the  vocal  organ 
may  be  determined,  their  chief  results  will  be  here  given. — I.  The  pitch  of  a  reed 
may  be  lowered,  but  cannot  be  raised,  by  joining  it  to  a  tube.     n.  The  sinking 
of  the  pitch  of  the  reed  thus  produced,  is  at  the  utmost  not  more  than  an  octave. 
in.  The  fundamental  note  of  the  reed  thus  lowered,  may  be  raised  again  to  its 
original  pitch,  by  a  further  lengthening  of  the  tube ;  whilst  by  a  further  increase 
it  is  again  lowered,     iv.  The  length  of  tube  necessary  to  lower  the  pitch  of  the 
instrument  to  any  given  point,  depends  on  the  relation  which  exists  between  the 
frequency  of  the  vibrations  of  the  tongue  of  the  reed,  and  those  of  the  column  of 
air  in  the  tube,  each  taken  separately. — From  these  data,  and  from  those  of  the 
preceding  paragraph,  it  follows  that,  if  a  wind-instrument  can,  by  the  prolonga- 
tion of  its  tube,  be  made  to  yield  tones  of  any  depth  in  proportion  to  the  length 
of  the  tube,  it  must  be  regarded  as  a  flute-pipe ;  whilst  if  its  pitch  can  only  be 
lowered  an  octave  or  less  (the  embouchure  remaining  the  same)  by  lengthening 
the  tube,  we  may  be  certain  that  it  is  a  reed  instrument.     The  latter  proves  to 
be  the  case  in  regard  to  the  Larynx. 


OF    THE    LARYNX    AND     ITS   ACTIONS. 


723 


810.  It  is  evident  from  the  foiegoing  considerations,  that  the  action  of  the 
Larynx  has  more  analogy  to  that  of  reed  instruments,  than  it  has  to  that  either  of 
vibrating  strings  or  of  flute  pipes;  and  though  there  would  seem,  at  first  sight,  to 
be  a  marked  difference  in  character  between  the  vocal  ligaments  and  the  tongue 
of  any  reed  instrument,  this  difference  is  really  by  no  means  considerable.  In  a 
reed,  elasticity  is  a  property  of  the  tongue  itself,  when  fixed  at  one  end,  the  other 
vibrating  freely;  but  by  a  membranous  lamina,  fixed  in  the  same  manner,  no 
tone  would  be  produced.  If  such  a  lamina,  however,  be  made  elastic  by  a  mode- 
rate degree  of  tension,  and  be  fixed  in  such  a  manner  as  to  be  advantageously 
acted-on  by  a  current  of  air,  it  will  give  a  distinct  tone.  It  is  observed  by  Miiller, 
that  membranous  tongues  made  elastic  by  tension,  may  have  either  of  three  dif- 
ferent forms  . — I.  That  of  a  band  extended  by  a  cord,  and  included  between  two 
firm  plates,  so  that  there  is  a  cleft  for  the  passage  of  air  on  each  side  of  the  tongue. 
II.  The  elastic  membrane  may  be  stretched  over  the  half  or  any  portion  of  the 
end  of  a  short  tube,  the  other  part  being  occupied  by  a  solid  plate,  between  which 
and  the  elastic  membrane  a  narrow  fissure  is  left.  in.  Two  elastic  membranes 
may  be  extended  across  the  mouth  of  a  short  tube,  each  covering  a  portion  of 
the  opening,  and  having  a  chink  left  open  between  them. — This  last  is  evidently 
the  form  most  allied  to  the  Human  Glottis ;  but  it  may  be  made  to  approximate 
still  more  closely,  by  prolonging  the  membranes  in  a  direction  parallel  to  that  of 
the  current  of  air,  so  that  not  merely  their  edges,  but  their  whole  planes,  shall  be 
thrown  into  vibration.  Upon  this  principle,  a  kind  of  artificial  glottis  has  been 
constructed  by  Mr.  Willis ;  the  conditions  of  action  and  the  effects  of  which  are 
so  nearly  allied  to  that  of  the  real  instrument,  that  the  similar  character  of  the 
two  can  scarcely  be  doubted.  The  following  is  his  description  of  it.  "  Let  a 
wooden  pipe  be  prepared  of  the  form  of  Fig.  191  a,  having  a  foot,  c,  like  that  of 
an  organ-pipe,  and  an  upper  opening,  long  and  narrow,  as  at  B,  with  a  point,  A, 
rising  at  one  end  of  it.  If  a  piece  of  leather,  or  still  better,  of  sheet  India-rubber, 
be  doubled  round  this  point,  and  secured  by  being  bound  round  the  pipe  at  D  with 
strong  thread,  as  in  Fig.  191  6,  it  will 

give   us    an   artificial  glottis   with   its  FIG.  191. 

upper  edges  G  H,  which  may  be  made 
to  vibrate  or  not,  at  pleasure,  by  inclin- 
ing the  planes  of  the  edges.  A  couple 
of  pieces  of  cork,  E  F,  may  be  glued  to 
the  corners,  to  make  them  more  man- 
ageable. From  this  machine,  various 
notes  may  be  obtained,  by  stretching 
the  edges  in  the  direction  of  their 
length  Q  H ;  the  notes  rising  in  pitch 
with  the  increased  tension,  although  the 
length  of  the  vibrating  edge  is  increased. 
It  is  true  that  a  scale  of  notes  equal  in 
extent  to  that  of  the  human  voice, 
cannot  be  obtained  from  edges  of  lea- 
ther ;  but  this  scale  is  much  greater  in 
India-rubber  than  in  leather;  and  the 
elasticity  of  them  both  is  so  much  Artificial  Glottis, 

inferior  to  that  of  the  vocal  ligaments, 

that  we  may  readily  infer  that  the  greater  scale  of  the  latter  is  due  to  its  greater 
elastic  powers."  By  other  experimenters,  the  tissue  forming  the  middle  coat  of 
the  arteries  has  been  used  for  this  purpose,  in  the  moist  state,  with  great  suc- 
cess; with  this,  the  tissue  of  the  vocal  ligament  is  nearly  identical.  It  is  worthy 
of  remark  that,  in  all  such  experiments,  it  is  found  that  the  two  membranes  may 
be  thrown  into  vibration,  when  inclined  towards  each  other  in  various  degree*,  or 
even  when  they  are  in  parallel  planes,  and  their  edges  only  approximate ;  but 


724  OF    THE     VOICE    AND     SPEECH. 

that  the  least  inclination  from  each  other  (which  is  the  position  the  vocal  liga- 
ments have  during  the  ordinary  state  of  the  glottis,  §  806),  completely  prevents 
any  sonorous  vibrations  from  being  produced. 

811.  The  pitch  of  the  notes  produced  by  membranous  tongues,  may  be  affected 
in  several  ways.     Thus,  an  increase  in  the  strength  of  the  blast,  which  has  little 
influence  on   metallic  reeds,  raises  their  pitch  very  considerably ;  and   in   this 
manner  the  note  of  a  membranous  reed  may  be  raised  by  semitones,  to  as  much  as 
a  fifth  above  the  fundamental.     The  addition  of  a  pipe  has  nearly  the  same  effect 
on  their  pitch,  as  on  that  of  metallic  reeds ;  but  it  cannot  easily  be  determined  * 
with  the  same  precision.     Several  different  notes  may  be  produced  with  a  pipe 
of  the  same  length;  but  there  is  a  certain  length  of  the  column  of  air,  which  is 
the  one  best  adapted  for  each  tone.     It  has  been  recently  ascertained,  moreover, 
that  the  length  of  the  pipe  prefixed  to  the  reed  has  a  considerable  influence  on  its 
tone,  rendering  it  deeper  in  proportion  as  it  is  prolonged,  down  to  nearly  the 
octave  of  the  fundamental  note;  but  the  pitch  then  suddenly  rises  again,  as  in 
the  case  of  the  tube  placed  beyond  the  reed.     The  researches  of  Miiller,  how- 
ever, have  not  succeeded  in  establishing  any  very  definite  relation  between  the 
lengths  of  the  two  tubes,  in  regard  to  their  influence  on  the  pitch  of  the  reed 
placed  between  them. 

812.  From  the  foregoing  statements  it  appears,  that  the  true  theory  of  the 
Voice  may  now  be  considered  as  well  established,  in  regard  to  this  essential  par- 
ticular,— that  the  sound  is  the  result  of  the  vibrations  of  the  vocal  ligaments, 
which  take  place  according  to  the  same  laws  with  those  of  metallic  or  other  elastic 
tongues;  and  that  the  pitch  of  the  notes  is  chiefly  governed  by  the  tension  of 
these  laminae.1     With  respect,  however,  to  the  mode  and  degree  in  which  these 
tones  are  modified  by  the  shape  of  the  air-passages,  both  above  and  below  the 
larynx,  by  the  force  of  the  blast,  and  by  other  concurrent  circumstances,  little  is 
certainly  known ;  but  no  doubt  can  be  felt  that  these  modifications  are  of  great 
importance,  when  we  observe  the  great  amount  of  muscular  action  which  takes 
place  consentaneously  with  the  production  of  vocal  tones,  and  which  seems  de- 
signed to  alter  the  length  and  tension  of  the  various  parts  of  the  vocal  tube,  so 
that  they  may  vibrate  synchronously  with  the  vocal  cords.     Thus,  during  the 
ascent  of  the  voice  from  the  deeper  to  the  higher  notes  of  the  scale,  we  find  the 
whole  larynx  undergoing  an  elevation  towards  the  base  of  the  cranium,  the  thy- 
roid cartilage  being  drawn-up  within  the  os-hyoides,  so  as  even  to  press  on  the 
epiglottis;  at  the  same  time,  the  small  space  between   the  thyroid  and  cricoid 
cartilages,  or  crico-thyroid  chink,  is  closed  by  the  depression  of  the  front  of  the 
former  upon  the  latter  (§  804) ;  the  velum  palati  is  depressed  and  curved  for- 
wards ;  and  the  tonsils  approach  one  another.     The  reverse  of  all  these  move- 
ments takes  place  during  the  descent  of  the  voice. — A  very  important  adjunct  to 
the  production  of  the  higher  notes  has  been  pointed-out  by  Miiller,  as  being 
afforded  by  the  modification  in  the  space  included  between  the  two  sides  of  the 
thyroid  cartilage,  which  is  effected  by  the  thyro-arytenoidei.    He  had  experimen- 
tally ascertained  that  the  introduction  of  a  hollow  plug  into  the  upper  end  of  the 
pipe  beneath  his  artificial  larynx  (and  therefore  just  below  the  reed),  by  dirni- 

1  It  is  considered,  however,  by  Mr.  Bishop  ("Cyclop,  of  Anat.  and  Physiol,"  vol.  iv. 
p.  1486),  that  the  vocal  apparatus  combines  the  properties  of  a  stretched  cord,  a  mem- 
branous pipe  with  a  column  of  air  vibrating  in  it,  and  a  reed ;  and  is  the  perfect  type,  of 
which  these  instruments  are  only  imperfect  adaptations.  The  Author  is  -unable,  however, 
to  deduce  from  Mr.  Bishop's  previous  statements  the  grounds  upon  which  he  makes  this 
assertion  ;  and  does  not  understand  how  any  instrument  can  combine  the  actions  of  strings 
and  of  tongues,  the  laws  of  whose  vibration  are  so  different.  That  the  column  of  air  in  the 
air-passages  is  thrown  into  vibration  consentaneously  with  the  production  of  sound  by  the 
vocal  cords,  and  intensifies  that  sound  by  reciprocation,  can  scarcely  be  doubted  ;  but  the 
reasons  previously  given  appear  to  the  Author  sufficient  to  disprove  the  notion,  that  this 
vibration  is  at  all  more  essential  to  the  production  of  the  vocal  tone,  that  it  is  in  the  reed- 
pipe  of  an  organ. 


OF    THE    LARYNX,     AND     ITS    ACTIONS.  725 

nishing  its  aperture,  produced  a  considerable  elevation  of  the  tone.  The  action 
may  be  imitated  in  the  human  larynx,  when  made  the  subject  of  experiment,  by 
compressing  the  thyroid  cartilage  laterally ;  and  in  this  manner,  the  natural  voice 
can  be  made  to  extend  through  a  range  that  could  otherwise  be  only  reached  by 
a  falsetto. — The  influence  of  the  prefixed  and  superadded  tubes,  in  modifying  the 
tones  produced  by  the  Human  larynx,  has  been  found  by  Prof.  Miiller  not  to  be  at 
all  comparable  to  that  which  they  exercised  over  the  artificial  larynx;  the  reason 
of  which  difference  does  not  seem  very  apparent.  It  appears,  however,  that  there  is 
a  certain  length  of  the  prefixed  tube — as  there  is  a  certain  distance  of  the  vibrat- 
ing laminae,  and  a  certain  length  or  form  of  the  tube  above, — which  is  most 
favourable  to  the  production  of  each  note  ;  and  the  downward  movement  of  the 
whole  vocal  organ,  which  takes-place  when  we  are  sounding  deep  notes,  and  its 
rise  during  the  elevation  of  the  tones,  have  been  supposed  to  answer  the  purpose 
of  making  this  adjustment  in  the  length  of  the  trachea;  but  this  requires  the 
supposition,  that  the  real  length  of  the  trachea  is  shortened  whilst  it  appears  ex- 
tended,— for  which  there  seems  no  foundation.  It  is  considered  by  Mr.  Wheat- 
stone,  that  the  column  of  air  in  the  trachea  may  divide  itself  into  (  harmonic 
lengths/  and  may  produce  a  reciprocation  of  the  tone  given  by  the  vocal  liga- 
ments (§  778);  and  in  this  manner  he  considers  that  the  falsetto  notes  are  to  be 
explained.  It  may  be  added,  that  the  partial  closing  of  the  epiglottis  seems  to 
assist  in  the  production  of  deep  notes,  just  as  the  partial  covering  of  the  top  of 
a-  short  pipe  fixed  to  a  reed  will  lower  its  tone ;  and  that  something  of  this  kind 
takes  place  during  natural  vocalisation,  would  appear  from  the  contraction  and 
depression  of  the  tongue,  which  accompany  the  lowering  of  the  front  of  the  head, 
when  the  very  lowest  notes  are  being  sounded.  The  experiments  of  Savart  have 
shown,  that  a  cavity  which  only  responds  to  a  shrill  note,  when  its  walls  are  firm 
and  dry,  may  be  made  to  afford  a  great  variety  of  lower  tones,  when  its  walls  are 
moistened  and  relaxed  in  various  degrees.  This  observation  may  probably  be 
applied  also  to  the  trachea. 

813.  The  falsetto  is  a  peculiar  modification  of  the  voice,  differing  from  the 
'  chest  voice/  not  merely  in  the  higher  pitch  of  its  notes,  but  also  in  their  quality  ; 
its  tones  being  less  reedy,  and  more  like  the  '  harmonic  notes '  of  stringed  and 
wind  instruments.  In  some  individuals  the  chest-voice  passes  by  imperceptible 
gradations  into  the  falsetto,  whilst  in  others  the  transition  is  abrupt;  and  some 
persons  can  sound  the  same  notes  in  the  two  different  registers,  these  notes  form- 
ing the  upper  part  of  the  scale  of  the  chest-voice,  and  the  lower  part  of  the  fal- 
setto.1— With  regard  to  the  theory  of  the  production  of  the  falsetto  voice,  there 
has  been  considerable  difference  of  opinion  amongst  Physiologists ;  and  it  cannot 
be  regarded  as  fully  determined.  By  Magendie  and  Mayo  it  was  maintained  that 
these  tones  are  produced  by  the  vibration  of  the  vocal  cords  along  only  half  their 
length,  the  rima  glottidis  being  partly  closed;  and  this  explanation  is  consistent 
with  the  fact,  that  a  far  smaller  quantity  of  air  is  required  for  sustaining  a  fal- 
setto note,  than  for  a  note  of  the  ordinary  register,  even  though  they  should  be 
of  the  same  pitch.  By  Miiller,  again,  it  is  asserted  that  in  the  production  of  the 
falsetto  notes,  merely  the  thin  border  of  the  glottis  vibrates,  so  that  the  fissure 
remains  distinctly  visible  :  whilst,  in  the  production  of  the  ordinary  vocal  tones, 
the  whole  breadth  of  the  vocal  ligaments  is  thrown  into  strong  vibrations,  which 
traverse  a  wider  space,  so  that  a  confused  motion  is  seen  in  the  lips  of  the  glottis, 

1  Thus  a  gentleman  of  the  Author's  acquaintance  has  a  bass  voice  of  a  harsh  reedy  cha- 
racter, ranging  from  the  C  below  the  bass  cleff  to  the  D  above  it  (two  octaves) ;  whilst  his 
falsetto,  which  is  remarkable  for  its  clearness  and  smoothness,  ranges  from  the  A  on  the 
highest  line  of  the  bass  cleff  to  the  E  in  the  highest  space  of  the  treble  cleff.  Hence  there 
are  five  notes  common  to  the  two  registers,  and  the  entire  voice  ranges  through  more  than 
three  octaves ;  but  from  want  of  a  gradual  passage  from  one  to  the  other,  this  gentleman 
can  only  sing  bass  parts  with  his  chest-voice,  or  alto  parts  with  his  falsetto,  the  tenor  scale 
extending  above  the  range  of  one,  and  below  that  of  the  other. 


726  OF    THE    VOICE    AND    SPEECH. 

rendering  its  fissure  indefinite.  It  is  not  impossible  that  both  these  doctrines 
may  be  correct;  and  that,  in  the  production  of  falsetto  notes,  the  vocal  ligaments 
are  in  contact  with  each  other  for  part  of  their  length,  their  thin  edges  only 
being  in  vibration  in  the  remainder.  It  has  been  pointed-out  by  Mr.  Bishop 
(loc.  cit.),  that  at  the  moment  of  transition  from  the  'chest-voice'  to  the  'fal- 
setto-voice/ the  crico-thyroid  chink,  which  was  closed  during  the  production  of 
the  highest  note  of  the  former,  suddenly  opens  on  the  production  of  the  lowest 
note  of  the  latter ;  thus  indicating  that  the  Vocal  Cords  are  relaxed  in  the  pas- 
sage from  the  one  to  the  other,  as  must  be  the  case,  if,  for  the  production  of  the 
same  note,  they  be  only  put  in  vibration  along  a  part  of  their  length ;  so  that  it 
would  not  seem  improbable  that  the  cause  of  those  differences  in  the  mode  of 
transition  which  have  been  already  noticed,  lies  in  the  difference  in  the  propor- 
tional amount  in  the  vocal  cords,  which  is  thus  thrown-out  of  use  by  the  partial 
approximation  of  the  two  lips  of  the  rima  glottidis.  It  is  further  remarked  by 
Mr.  Bishop,  that,  in  the  passage  from  the  chest  to  the  falsetto-voice,  the  larynx 
descends  from  its  previously-elevated  position,  and  gradually  rises  again  with  the 
ascending  scale  of  falsetto  notes ;  and  he  mentions  a  case  of  double  falsetto,  in 
which  a  third  register  existed,  and  in  which  the  relaxation  of  the  Vocal  cords  and 
the  descent  of  the  larynx  were  observed  at  its  commencement,  as  at  the  com- 
mencement of  the  second  or  ordinary  falsetto  register. — An  entirely  different 
theory  of  the  falsetto  has  been  given,  however,  by  MM.  Petrequin  and  Diday;1 
who  consider  that  the  falsetto  notes  are  not  produced  by  the  vibration  of  the 
vocal  cords,  but  are  really  l  flute-notes,'  formed  by  the  vibrations  of  the  column 
of  air  to  which  the  rima-glottidis  then  serves  as  the  embouchure.  This  view 
harmonizes  well  with  some  of  the  phenomena  of  the  falsetto-voice  ;  but  it  is  open 
to  the  objections  already  stated  in  regard  to  the  flute-theory  generally.  It  may 
be  added  that  some  have  attempted  to  show,  that  the  falsetto  depends  upon  a 
peculiar  action  of  the  parts  above  the  larynx ;  but  for  this  doctrine  there  is  no 
foundation  whatever. 

814.  The  various  muscular  actions  which  are  employed  in  the  production  and 
regulation  of  the  Voice,  are  called-forth  by  an  impulse  which  has  been  shown 
(§§  542,  547)  to  be  really  automatic  in  its  operation,  and  to  be  completely  under 
the  influence  of  guiding  sensations,  although  usually  originating  in  a  Volitional 
determination,  or  giving  expression  to  Emotions  or  simply  to  Ideas.  This,  how- 
ever, has  been  proved  to  be  also  true  of  all  Volitional  movements;  so  that  the 
production  of  vocal  tones  constitutes  no  real  exception.  It  may  be  safely  affirmed, 
that  the  simple  utterance  of  sounds  is  in  itself  an  Instinctive  action  ;  although  the 
combination  of  these,  whether  into  music  or  into  articulate  language,  is  a  matter 
of  acquirement,  which  is  much  more  readily  made  by  some  individuals  than  by 
others.  No  definite  tone  can  be  produced  by  a  Voluntary  effort,  unless  that  tone 
be  present  to  the  consciousness  during  an  interval — however  momentary, — either 
as  immediately  produced  by  an  act  of  Sensation,  recalled  by  an  act  of  Conception, 
or  anticipated  by  an  effort  of  the  Imagination.  When  thus  present,  the  Will  can 
enable  the  muscles  to  assume  the  condition  requisite  to  produce  it ;  but  under  no 
other  circumstances  does  this  happen,  except  through  the  particular  mode  of  dis- 
cipline by  which  the  congenitally-deaf  may  be  trained  to  speak.  Such  persons 
are  debarred  from  learning  the  use  of  Voice  in  the  ordinary  manner ;  for  the 
necessary  guidance  cannot  be  afforded,  either  through  sen-sations  of  the  present  or 
conceptions  of  the  past,  and  the  imagination  is  entirely  destitute  of  power  to  sug- 
gest that  which  has  been  in  no  shape  experienced.  But  they  may  be  taught  to 
acquire  an  imperfect  speech,  by  causing  them  to  imitate  particular  muscular 
movements,  which  they  may  be  made  to  see;  being  guided  in  the  imitation  of 
those  movements,  in  the  first  place  by  watching  their  own  performance  of  them 
in  a  looking-glass,  and  afterwards  by  attending  to  the  muscular  sensations  which 

1  "Gazette  Me"dicale,  "  1844. 


OF    ARTICULATE    SOUNDS.  727 

accompany  them.  Many  instances,  indeed,  are  on  record,  in  which  persons  en- 
tirely deaf  were  enabled  to  carry-on  a  conversation  in  the  regular  way;  judging 
of  what  was  said  by  the  movements  of  the  lips  and  tongue,  which  they  had 
learned  to  connect  with  particular  syllables ;  and  regulating  their  own  voices  in 
reply,  by  their  voluntary  power,  guided  in  its  exercise  by  their  muscular  sensa- 
tions.1 

[In  the  foregoing  account  of  the  Physiology  of  Voice,  the  Author  has  been  chiefly  guided 
by  the  excellent  paper  by  Mr.  Willis  in  the  "  Transactions  of  the  Cambridge  Philosophical 
Society,"  vol.  iv.  ;  and  by  the  elaborate  investigations  of  Miiller  and  his  coadjutors,  as 
detailed  in  the  Fourth  Book  of  his  Physiology. — Mr.  J.  Bishop's  article  « Voice,'  in  the 
Fourth  Volume  of  the  "  Cyclopaedia  of  Anatomy  and  Physiology,"  may  also  be  advan- 
tageously consulted.] 

2. —  Of  Articulate  Sounds. 

815.  The  larynx,  as  now  described,  is  capable  of  producing  those  tones  of 
which  Voice  fundamentally  consists,  and  the  sequence  of  which  becomes  Music  : 
but  Speech  consists  in  the  modification  of  the  laryngeal  tones,  by  other  organs 
intervening  between  the  Glottis  and  the  Os  externurn,  so  as  to  produce  those 
articulate  sounds  of  which  language  is  formed.     It  cannot  be  questioned  that 
Music  has  its  language ;  and  that  it  is  susceptible  of  expressing  Emotional  states 
of  the  mind  (among  those,  at  least,  who  have  been  accustomed  to  associate  these 
with  its  varied  modes)  to  even  a  higher  degree  than  articulate  speech  (§  610). 
But  it  is  incapable  of  addressing  the  Intellect,  by  conveying  definite  ideas  of 
objects,  properties,  actions,  &c.,  in  any  other  way  than  by  a  kind  of  imitation, 
which  may  be  compared  to  the  signs  used  in  hieroglyphic  writing.     These  ideas 
it  is  the  peculiar  province  of  Articulate  Language  to  convey  (§  613) ;  and  we 
find  that  the  vocal  organ  is  adapted  to  form  a  large  number  of  simple  sounds, 
which  may  be  readily  combined  into  groups,  forming  words.     The  number  of 
combinations  which  can  be  thus  produced,  is  so  inexhaustible,  that  every  lan- 
guage has  its  own  peculiar  series ;  no  difficulty  being  found  in  forming  new  ones 
to  express  new  ideas.     There  is  considerable  diversity  in  different  languages, 
even  with  regard  to  the  use  of  the  simplest  of  these  combinations  ;  some  of  them 
are  more  easy  of  formation  than   others,  and  these  accordingly  enter  into  the 
composition  of  all  languages;  whilst  of  the  more  difficult  ones,  some  are  em- 
ployed in  one  language,  some  in  another, — no  one  language  possessing  them  all. 
Without  entering  into  any  detailed  account  of  the  mechanism  required  to  pro- 
duce each  of  these  simple  sounds,  a  few  general  considerations  will  be  offered  in 
regard  to   the  classification  of  them ;    and  the  peculiar  defect  of  articulation, 
termed  Stammering,  will  be  briefly  treated-of. 

816.  Vocal  sounds  are  divided  into  Vowels  and  Consonants;  and  the  distinc- 
tive characters  of  these  are  usually  considered  to  be,  that  the  Vowels  are  pro- 
duced by  the  Voice  alone,  whilst  the  sound  of  the  Consonant  is  formed  by  some 
kind  of  interruption  to  the  voice,  so  that  they  cannot  be  properly  expressed,  un- 
less conjoined  with  a  vowel.     The  distinction  may  be  more  correctly  laid-down, 
however,  in  this  manner  : — the  Vowel-sounds  are  continuous  tones,  modified  by 
the  form  of  the  aperture  through  which  they  pass-out;  whilst  in  sounding  Con- 
sonants, the  breath  suffers  a  more  or  less  complete  interruption,  in  its  passage 
through  parts  anterior  to  the  larynx.     Hence  the  really-simple  Vowel-sounds  are 
capable  of  prolongation  during  any  time  that  the  breath  can  sustain  them ;  this 
is  not  the  ease,  however,  with  the  real  Diphthongal  sounds  (of  which  it  will  pre- 
sently appear  that  the  English  i  is  one) ;  whilst  it  is  true  of  some  Consonants. 
It  seems  to  have  been  forgotten  by  many  of  those  who  have  written  upon  this 
subject,  that  the  laryngeal  voice  is  not  essential  to  the  formation  of  either  vowels 
or  consonants ;  for  all  may  be  sounded  in  a  whisper.     It  is  very  evident,  there- 

1  See  Dr.  Johnstone  "  On  Sensation,"  p.  128. 


728  OF    THE    VOICE    AND     SPEECH, 

fore,  that  the  larynx  is  not  primarily  concerned  in  their  production  ;  and  thia 
has  been  fully  established  by  the  following  experiment.  A  flexible  tube  was  in- 
troduced by  M.  Deleau  through  his  nostril  into  the  pharynx,  and  air  was  impelled 
by  it  into  the  fauces  ;  then,  closing  the  larynx,  he  threw  the  fauces  into  the  dif- 
ferent positions  requisite  for  producing  articulate  sounds,  when  the  air  impelled 
through  the  tube  became  an  audible  whisper.  The  experiment  was  repeated, 
with  this  variation,  —  that  the  laryngeal  sounds  were  allowed  to  pass  into  the 
fauces  ;  and  each  articulated  letter  was  then  heard  double,  in  a  proper  voice  and 
in  a  whisper. 

817.  That  the  Vowels  are  produced  by  simple  modifications  in  the  form  of  the 
external  passages,  is  easily  proved,  both  by  observation  and  by  imitative  experi- 
ment. When  the  mouth  is  opened  wide,  the  tongue  depressed,  and  the  velum 
palati  elevated,  so  as  to  give  the  freest  possible  exit  to  the  voice,  the  vowel  a  in 
its  broadest  form  (as  in  aJi}  is  sounded.1  On  the  other  hand,  if  the  oral  aper- 
ture be  contracted,  the  tongue  being  still  depressed,  the  sound  oo  (the  conti- 
nental u~)  is  produced.  If  attention  be  paid  to  the  state  of  the  buccal  cavity, 
during  the  pronunciation  of  the  different  vowel-sounds,  it  will  be  found  to  un- 
dergo a  great  variety  of  modifications,  arising  from  varieties  of  position  of  the 
tongue,  the  cheeks,  the  lips,  and  velum  palati.  The  position  of  the  tongue  is, 
indeed,  one  of  the  primary  conditions  of  the  variation  of  the  sound  ;  for  it  may 
be  easily  ascertained  that,  by  peculiar  inflexions  of  this  organ,  a  great  diversity 
of  vowel-sounds  may  be  produced,  the  other  parts  remaining  the  same.  Still 
there  is  a  certain  position  of  all  the  parts,  which  is  most  favourable  to  the  forma- 
tion of  each  of  these  sounds  ;  but  this  could  not  be  expressed  without  a  lengthened 
description.  The  following  table,  slightly  altered  from  that  of  Kempelen,  ex- 
presses the  relative  dimensions  of  the  buccal  cavity  and  of  the  oral  orifice,  for 


some  of  the 
the  others  in 

principal  of  these; 
like  proportion  :  — 

the 

number 

5  expressing 

the  largest  size, 

and 

Vowel.                      Sound. 

Size  of  oral  opening. 

Size  of  buccal  cavity. 

a 

as  in 

ah 

5 

5 

a 

as  in 

name 

4 

2 

e 

as  in 

theme 

3 

1 

0 

as  in 

cold 

2 

4 

DO 

as  in 

cool 

1 

6 

These  are  the  sounds  of  the  five  vowels,  a,  e,  i,  o,  u,  in  most  Continental  lan- 
guages; and  it  cannot  but  be  admitted,  that  the  arrangement  is  a  much  more 
natural  one  than  that  of  our  own  vowel  series.  The  English  a  has  three  dis- 
tinct sounds  capable  of  prolongation  ;2  —  the  true  broad  a  of  ah,  slightly  modified 
in  far]  the  a  of  fate,  corresponding  to  the  e  of  French;  and  the  a  of  fall, 
which  should  be  really  represented  by  ait.  This  last  is  a  simple  sound,  though 
commonly  reckoned  as  a  diphthong.  In  Kempelen's  scale,  the  oral  orifice  re- 
quired to  produce  it  would  be  about  3,  and  the  size  of  the  buccal  cavity  4.3  On 
the  other  hand,  the  sound  of  the  English  i  cannot,  like  that  of  a  true  vowel,  be 
prolonged  ad  libitum  ;  it  is  in  fact  a  sort  of  diphthong,  resulting  from  the  tran- 
sition from  a  peculiar  indefinite  murmur  to  the  sound  of  e,  which  takes  its  place 
when  we  attempt  to  continue  it.  The  sound  oy  or  oi,  as  in  oil,  is  a  good  example 

1  This  sound  of  the  vowel  a  is  scarcely  used  in  our  language,  though  very  common  in 
most  of  the  Continental  tongues;  the  nearest  approach  to  it  in  English  is  the  a  in  far; 
but  this  is  a  very  perceptible  modification,  tending  towards  au. 

3  The  short  vowel  sounds,  as  a  in  fat,  e  in  met,  o  in  pot,  &c.,  are  not  capable  of  prolon- 
gation. 

3  The  mode  of  making  a  determination  of  this  kind  may  here  be  given,  for  the  sake  of 
example.  If  the  broad  a  be  sounded,  the  mouth  and  fauces  being  opened  wide,  and  we 
contract  the  oral  orifice  by  degrees,  at  the  same  time  slightly  elevating  the  point  of  the 
tongue,  we  gradually  come  to  the  sound  of  au;  by  still  further  contracting  the  orifice,  and 
again  depressing  the  tongue,  we  form  oo.  On  the  other  hand,  in  sounding  e,  the  tongue 
is  raised  nearly  to  the  roof  of  the  mouth;  if  it  be  depressed  without  the  position  of  the 
Jips  being  altered,  au  is  given 


OF    ARTICULATE    SOUNDS.  729 

of  the  true  diphthong;  being  produced  by  the  transition  from  ait  to  e.  In  the 
same  manner,  the  diphthong  ou,  which  is  the  same  with  ow  in  owl,  is  produced 
in  the  rapid  transition  from  the  broad  a  of  ah,  to  the  oo  of  cool. — Much  discus- 
sion has  taken-place  as  to  the  true  character  of  y,  when  it  commences  a  word,  as 
in  yet,  yawl,  &c.  ;  some  having  maintained  that  it  is  a  consonant  (for  the 
very  unsatisfactory  reason,  that  we  are  in  the  habit  of  employing  a  rather  than  an, 
when  we  desire  to  prefix  the  indefinite  article  to  such  words),  whilst  others  re- 
gard it  as  a  peculiar  vowel.  A  slight  attention  to  the  position  of  the  vocal  organs 
during  its  pronunciation,  makes  it  very  clear,  that  its  sound  in  such  words  really 
corresponds  with  that  of  the  long  (English)  e;  the  pronunciation  of  the  word 
yawl  being  the  same  as  that  of  eaul,  when  the  first  sound  is  not  prolonged,  but 
rapidly  transformed  into  the  second.  The  sound  of  the  letter  10,  moreover,  is 
really  of  the  vowel  character,  being  formed  in  the  rapid  transition  from  oo  to  the 
succeeding  vowel ;  thus  wall  might  be  spelt  doall.  Many  similar  difficulties 
might  be  removed,  and  the  conformity  between  spoken  and  written  language 
might  be  greatly  increased  (so  as  to  render  far  more  easy  the  acquirement  of 
the  former  from  the  latter),  by  due  attention  to  the  state  of  the  vocal  organs  in 
the  production  of  the  simple  sounds. 

818.  It  is  not  very  difficult  to  produce  a  tolerably  good  artificial  imitation   of 
the  Vowel-sounds.     This  was  accomplished  by  Kempelen,  by  means  of  an  India- 
rubber  ball,  with  an  orifice  at  each  end,  of  which  the  lower  one  was  attached  to 
a  reed  :  by  modifying  the  form  of  the  ball,  the  different  vowels  could  be  sounded 
during  the  action  of  the  reed.     He  also  employed  a  short  funnel-like  tube,  and 
obtained  the  different  sounds  by  covering  its  wide  opening  to  a  greater  or  less 
extent.     This  last  experiment   has  been  repeated  by  Mr.  Willis;  who  has  also 
found  that  the  vowel  sounds  might  be  imitated,  by  drawing-out  a  long  straight 
tube  from  the  reed.     In  this  experiment  he  arrived  at  a  curious  result : — with  a 
tube  of  a  certain  length,  the  series  of  vowels,  i,  e,  a,  o,  u,  was  obtained  by  gra 
dually  drawing  it  out ;  but,  if  the  length  was  increased  to  a  certain  point,  a 
further  gradual  increase  would  produce  the  same  sequence  in  an  inverted  order, 
u,  o,  a,  e,  i;  a  still  further  increase  would  produce  a  return  to  the  first  scale,  and 
so  on.     When  the  pitch  of  the  reed  was  high,  and  the  pipe  short,  it  was  found 
that  the  vowels  o  and  u  could  not  be  distinctly  formed, — the  proper  tone  being 
injured  by  the  elongation  of  the  pipe  necessary  to  produce  them ;  and  this,  Mr. 
Willis  remarks,  is  exactly  the  case  in  the  Human  voice,  most  singers  being  un- 
able to  pronounce  u  and  o  upon  their  highest  notes. 

819.  The  most  natural  primary  division  of  the  Consonants,  is  into  those  which 
require  a  total  stoppage  of  the  breath  at  the  moment  previous  to  their  being  pro- 
nounced,  and  which,  therefore,  cannot  be  prolonged ;  and  those  in  pronouncing 
which  the  interruption  is  partial,  and  which  can,  like  the  vowel  sounds,  be  pro- 
longed ad  libitum.     The  former  have  received  the  designation  of  explosive; 
and  the  latter  of  continuous. — In  pronouncing  the  explosive  consonants,  the  pos 
terior  nares  are  completely  closed,  so  that  the  exit  of  air  through  the  nose  is 
altogether  prevented;  and  the  current  may  be  checked  in  the  mouth  in  three 
ways, — by  the- approximation  of  the  lips, — by  the  approximation  of  the  point  of 
the  tongue  to  the  front  of  the  palate, — and  by  the  approximation  of  the  middle 
of  the  tongue  to  the  arch  of  the  palate.     In  the  first  of  these  modes,  we  pro- 
nounce the  letters  b  and  p;  in  the  second,  d  and  t;  in  the  third,  the  hard  y 
and  k.     The  difference  between  b,  d,  and  g,  on  the  one  hand,  and  p,  t,  and  &,1 
on  the  other,  seems  to  depend  on  this; — that  in  the  former  group  the  approxi- 
mating surfaces  are  larger,  and  the  breath  is  sent  through  them  more  strongly  at 
the  moment  of  opening,  than  in  the  latter. — The  continuous  consonants  may  be 
again   subdivided,  according  to  the  degree  of  freedom  with  which  the  air  is 
allowed  to  make  its  exit,  and  the  compression  which  it  consequently  experiences. 

1  For  the  sake  of  proper  comparison,  this  letter  should  be  sounded  not  as  kay  but  key. 


780  OF    THE    VOICE    AND    SPEECH. 

I.  The  first  class  includes  those,  in  which  no  passage  of  air  takes-place  through 
the  nose,  and  in  which  the  parts  of  the  mouth  that  produce  the  sound  aie  nearly 
approximated  together,  so  that  the  compression  is  considerable.  This  is  the  case 
with  v  and  f,  which  are  produced  by  approximating  the  upper  incisors  to  the 
lower  lip ;  and  which  stand  in  nearly  the  same  relation  to  each  other,  as  that 
which  exists  between  d  and  t,  or  b  and  p.  The  sibilant  sounds,  zt  and  s,  also 
stand  in  a  similar  relation  to  each  other;  they  are  produced  by  the  passage  of  air 
between  the  point  of  the  tongue  and  the  front  of  the  palate,  the  teeth  being  at 
the  same  time  nearly  closed.  The  simple  sound  sh,  is  formed,  by  narrowing  the 
channel  between  the  dorsum  of  the  tongue  and  the  palate ;  the  former  being  ele- 
vated towards  the  latter,  through  a  considerable  part  of  its  length.  If,  in  sound- 
ing s,  we  raise  the  point  of  the  tongue  a  very  little,  so  as  to  touch  the  palate, 
the  sound  of  t  is  evolved;  and  in  the  same  manner  d  is  produced  from  z.  This 
class  also  includes  the  th;  which,  being  a  perfectly-simple  sound,  ought  to  be 
expressed  by  a  single  letter,  as  in  Greek,  instead  of  by  two,  whose  combination 
does  not  really  produce  anything  like  it.  For  producing  this  sound,  the  point 
of  the  tongue  is  applied  to  the  back  of  the  incisors,  or  to  the  front  of  the  palate, 
as  in  sounding  t;1  but,  whilst  there  is  complete  contact  of  the  tip,  the  air  is 
allowed  to  pass-out  around  it. — u.  In  the  second  class  of  continuous  consonants, 
including  the  letters  m,  n,  I,  and  r,  the  nostrils  are  not  closed ;  and  the  air  thus 
undergoes  very  little  compression,  even  though  the  passage  of  air  through  the 
oral  cavity  is  almost  or  completely  checked.  In  pronouncing  m  and  w,  the  breath 
passes  through  the  nose  alone  :  and  the  difference  of  the  sound  of  these  two 
letters  must  be  due  to  the  variation  in  the  form  of  the  cavity  of  the  mouth,  which 
acts  by  resonance.  The  letter  m  is  a  labial,  like  b;  but  in  the  former  the  nasal 
passage  is  open,  the  mouth  remaining  closed,  whilst  in  the  latter  the  nose  is  en- 
tirely closed,  and  the  sound  is  formed  at  the  moment  of  opening  the  mouth ; 
hence  the  passage  from  m  to  b  is  made  with  great  facility.  The  same  corres- 
pondence exists  between  n  and  t,  or  n  and  g  (the  particular  part  of  the  tongue 
approximated  to  the  palate  not  being  of  much  consequence  in  the  pronunciation 
of  n) ;  and  hence  it  is  that  the  transition  from  n  to  t,  or  from  n  to  g,  is  so  easy 
that  the  combinations  nt  and  ng  are  found  abundantly  in  most  languages.  The 
sound  of  I  is  produced  by  bringing  the  tip  of  the  tongue  into  contact  with  the 
palate,  and  allowing  the  air  to  escape  around  it,  at  the  same  time  that  a  vocal 
tone  is  generated  in  the  larynx;  it  differs,  therefore,  from  th  in  the  position  at 
which  the  obstruction  is  interposed,  as  well  as  in  the  slight  degree  of  compression 
of  the  air  which  it  involves.  The  sound  of  the  letter  r  depends  on  an  absolute 
vibration  of  the  point  of  the  tongue,  in  a  narrow  current  of  air  forced  between 
the  tongue  itself  and  the  palate. — in.  The  sounds  of  the  third  class  are  scarcely 
to  be  termed  consonants,  since  they  are  merely  aspirations  caused  by  an  increased 
force  of  breath.  These  are  h,  and  the  guttural  ch*  of  most  foreign  languages 
(the  Greek  %).  The  first  is  a  simple  aspiration;  the  second  an  aspiration  modi- 
fied by  the  elevation  of  the  tongue,  causing  a  slight  obstruction  to  the  passage 
of  air,  and  an  increased  resonance  in  the  back  of  the  mouth.  This  sound  would 
become  either  g  or  k,  if  the  tongue,  whilst  it  is  being  produced,  were  carried-up 
to  touch  the  palate.3 

820.  These  distinctions  come  to  be  of  much  importance,  when  we  apply  our- 
selves to  the  treatment  of  defects  of  articulation.  Great  as  is  the  number  of  mus- 
cles employed  in  the  production  of  definite  vocal  sounds,  the  number  is  much 
greater  for  those  of  articulate  language ;  and  the  varieties  of  combination  which 

1  Hence  it  is  easy  to  understand  the  substitution  of  t  or  d,  for  the  English  th,  by 
foreigners. 

3  The  English  ch  is  merely  a  combination  of  t  "with  sh ;  thus  chime  might  be  spelt 
tihime. 

'"  The  general  classification  proposed  by  Dr.  M.  Hall  has  been  here  adopted,  with  some 
modification  as  to  the  details. 


OF    ARTICULATE    SOUNDS.  731 

we  are  continually  forming  unconsciously  to  ourselves,  would  not  be  suspected, 
without  a  minute  analysis  of  the  separate  actions.  Thus,  when  we  utter  the  ex- 
plosive sounds,  we  check  the  passage  of  air  through  the  posterior  nares,  in  the 
very  act  of  articulating  the  letter;  and  yet  this  important  movement  commonly 
passes  unobserved. — We  must  regard  the  power  of  forming  the  several  articulate 
sounds  which  have  been  adverted-to,  and  their  simple  combinations,  as  so  far 
resulting  from  intuition,  that  it  can  in  general  be  more  readily  acquired  by  early 
practice  than  other  actions  of  the  same  complexity;  but  we  find  that  among  dif- 
ferent Races  of  Men,  there  exist  tendencies  to  the  production  of  different  sounds, 
which,  though  doubtless  influenced  in  great  degree  by  early  habit  (since  we  find 
that  children,  when  first  learning  to  speak,  form  their  habits  of  vocalization  in  great 
degree  in  accordance  with  the  examples  amidst  which  they  are  placed),  are  cer- 
tainly also  dependent  in  part  upon  congenital  constitution,  as  we  often  see  in  the 
case  of  children  among  ourselves,  who  grow-up  with  certain  peculiarities  of  pro- 
nunciation, not  thus  derived  from  imitation,  of  which  they  do  not  seem  able  to 
divest  themselves. 

821.  It  is  in  the  want  of  power  to  combine  the  different  muscular  actions  con- 
cerned in  vocalization,  that  the  defect  termed  Stammering  essentially  consists. 
Many  theories  regarding  the  nature  of  this  impediment  have  been  proposed ; 
and  there  can  be  little  doubt  that  it  may  be  attributed  to  a  great  variety  of  ex- 
citing causes.  A  disordered  action  of  the  nervous  centres,  must,  however,  be 
regarded  as  the  proximate  cause;  though  this  maybe  (to  use  the  language  of  Dr. 
M.  Hall)  either  of  centric  or  of  excentric  origin, — that  is,  it  may  result  from  a 
morbid  condition  of  the  ganglionic  centre,  or  from  an  abnormal  impression  con- 
veyed through  its  afferent  nerves.  When  of  centric  origin  (and  this  is  probably 
the  most  general  case),  the  phenomena  of  Stammering  and  Chorea  have  a  close 
analogy  to  each  other  (§  712)  ;  in  fact,  stammering  is  frequently  one  of  the  modes 
in  which  the  disordered  condition  of  the  nervous  system  in  Chorea  manifests 
itself. — It  is  in  the  pronunciation  of  the  Consonants  of  the  explosive  class,  that 
the  stammerer  experiences  the  greatest  difficulty.  The  total  interruption  to  the 
breath  which  they  occasion,  frequently  becomes  quite  spasmodic;1  and  the  whole 
frame  is  thrown  into  the  most  distressing,  semi-convulsive  movement,  until  re- 
lieved by  expiration.  In  the  pronunciation  of  the  continuous  Consonants  of  the 
first  class,  the  stammerer  usually  prolongs  them,  by  a  spasmodic  continuance  of 
the  same  action  ;  and  there  is,  in  consequence,  an  impeded,  but  not  a  suspended 
respiration.  The  same  is  the  case  with  the  I  and  r  in  the  second  class.  In  pro- 
nouncing the  m  and  n,  on  the  other  hand,  as  well  as  the  aspirates  and  vowels,  it 
is  sometimes  observed  that  the  stammerer  prolongs  the  sound,  by  a  full  and  ex- 
hausting expiration.  In  all  these  cases,  then,  it  seems  as  if  the  muscular  sense, 
resulting  from  each  particular  combination  of  actions,  became  the  stimulus  to  the 
involuntary  prolongation  of  that  state.  It  is  possible  that  the  defect  may  result, 
in  some  instances,  from  malformation  of  the  parts  about  the  fauces,  producing  an 
abnormal  stimulus  of  this  kind  in  some  particular  positions  of  the  organ ;  and 
such  cases  may  be  really  benefitted  by  an  operation  for  the  removal  of  these  parts. 
But  the  effect  of  such  an  operation  is  certainly  exerted  in  most  cases  through  the 
mind  of  the  patient;  the  expectation  of  benefit  from  it  tending  to  improve  his 
command  over  the  muscles  of  vocalization,  which  Emotional  excitement  always 
impairs;  and  the  improvement  is  usually  proportional  to  the  confidence  which  he 
has  been  led  to  feel  in  the  result.  The  slightest  disturbance  of  the  feelings  is 
sufficient  in  most  Stammerers  to  induce  a  complete  perturbation  of  the  vocal 
powers;  the  very  fear  that  stammering  will  occur,  particularly  under  circum- 
stances which  render  it  peculiarly  annoying,  is  often  sufficient  to  bring  it  on  in  a 
predisposed  subject;  and  the  tendency  to  consensual  imitation  sometimes  occa- 

1  By  Dr.  Arnott  this  interruption  is  represented  as  taking  place  in  the  larynx ;  that 
such  is  not  usually  the  case,  the  Author  believes  that  a  little  attention  to  the  ordinary 
phenomena  of  voice  will  satisfactorily  prove. 


732  INFLUENCE    OF    THE    NERVOUS    SYSTEM. 

pious  stammering,  in  individuals  (especially  children)  who  never  show  the  slightest 
tendency  to  it  except  when  they  witness  the  difficulty  in  others. 

822.  The  method  proposed  by  Dr.  Arnott  for  the  prevention  of  Stammering, 
consists  in  the  connection  of  all  the  words  by  a  vocal  intonation,  in  such  a  man- 
ner, that  there  shall  never  be  an  entire  stoppage  of  the  breath.  It  is  justly  re- 
marked by  Miiller,  however,  that  although  this  plan  may  afford  some  benefit,  it 
cannot  do  everything;  since  the  main  impediment  occurs  in  the  middle  of  words 
themselves.  One  important  remedial  means,  on  which  too  much  stress  cannot  be 
laid,  is  to  study  carefully  the  mechanism  of  the  articulation  of  the  difficult  letters, 
and  to  practise  their  pronunciation  repeatedly,  slowly,  and  analytically.  The  pa- 
tient would  at  first  do  well  to  practise  sentences  from  which  the  explosive  conso- 
nants are  omitted ;  his  chief  difficulty,  arising  from  the  spasmodic  suspension  of 
the  expiratory  movement,  being  thus  avoided.  Having  mastered  these,  he  may 
pass-on  to  others,  in  which  the  difficult  letters  are  sparingly  introduced ;  and  may 
finally  accustom  himself  to  the  use  of  ordinary  language.  One  of  the  chief  points 
to  be  aimed-at,  is  to  make  the  patient  feel  that  he  has  command  over  his  muscles 
of  articulation  (§  625) ;  and  this  is  best  done,  by  gradually  leading  him  from  that 
which  he  finds  he  can  do,  to  that  which  he  fears  h'e  cannot.  The  fact  that  stam- 
mering people  are  able  to  sing  their  words  better  than  to  speak  them,  has  been 
usually  explained  on  the  supposition  that,  in  singing,  the  glottis  is  kept  open,  so 
that  there  is  less  liability  to  spasmodic  action ;  if,  however,  as  here  maintained, 
the  spasmodic  action  is  not  in  the  larynx,  but  in  the  velum  palati  and  the  mus- 
cles of  articulation,  the  difference  must  be  due  to  the  direction  of  the  attention 
rather  to  the  muscles  of  the  larynx  than  to  those  of  the  mouth. — One  of  the  most 
important  objects  to  be  aimed-at  in  the  treatment  of  stammering,  consists  in  the 
prevention  of  all  Emotional  disturbance  in  connection  with  the  act  of  Speech  ;  and 
this  requires  the  exercise  of  the  Voluntary  power  over  the  direction  of  the 
thoughts,  in  the  following  modes  : — 1.  To  reduce  mental  emotion,  by  a  daily, 
hourly,  habit  of  abstracting  the  mind  from  the  subject  of  stammering,  both  while 
speaking,  and  at  other  times.  2.  To  avoid  exciting  mental  emotion  by  attempt- 
ing unnecessarily  to  read  or  speak,  when  the  individual  is  conscious  that  he  shall 
not  be  able  to  perform  these  actions  without  great  distress.  8.  To  elude  mental 
emotion,  by  taking  advantage  of  any  little  artifice  to  escape  from  stammering,  so 
long  as  the  artifice  continues  to  be  a  successful  one. — Much  may  frequently  be 
done,  also,  by  constitutional  treatment,  adapted  to  improve  the  general  vigour  of 
the  nervous  system.1 


CHAPTER  XV. 

OF  THE   INFLUENCE   OF   THE   NERVOUS   SYSTEM    ON   THE   ORGANIC   FUNCTIONS. 

823.  OF  the  modes  in  which  the  Nervous  System  influences  the  Organic  Func- 
tions, a  great  part  have  been  already  considered  :  for  it  has  been  shown  to  be  con- 
cerned in  providing  the  mechanical  conditions,  either  immediate  or  remote*  under 
which  alone  these  functions  can  be  performed ;  so  that,  when  its  activity  ceases, 
they  cannot  be  much  longer  maintained.  But  the  influence  of  the  Nervous  Sys- 
tem is  not  alone  exerted  upon  the  motor  or  contractile  tissues  of  the  body;  for 
there  is  good  evidence  that  it  has  a  direct  operation  upon  the  molecular  changes 
which  constitute  the  functions  of  Nutrition,  Secretion,  &c. ;  and  this  view  may  be 
admitted  to  its  fullest  extent,  without  our  being  thereby  led  to  regard  the  pro- 
cesses in  question  as  dependent  upon  Nervous  agency, — a  doctrine  for  which  there 

1  See  on  the  subject  of  "  Stammering  and  its  Treatment,"  a  useful  pamphlet  under  this 
title,  by  Race.  Med.  Oxon.,  1850;  and  Mr.  Bishop's  treatise  "On  Articulate  Sounds,  and 
an  the  Causes  and  Cure  of  Impediments  of  Speech." 


ON    THE    ORGANIC    FUNCTIONS 


733 


seems  no  valid  foundation  (Chap.  IT.,  Sect.  2).     Throughout  the  Animal  body, 
it  may  be  observed  that,  the  more  Vegetative  the  nature  of  any  function,  the  less 


[FiG.  192. 


is  it  under  the  influence  of  the  Ner- 
vous System,  save  where  that  influence 
is  required  to  bring  it  into  harmony 
with  other  functions  (§  41),  sometimes 
by  exciting,  sometimes  by  checking, 
and  sometimes  by  otherwise  modifying 
them,  very  much  in  the  way  that  a 
rider  guides  and  controls  the  move- 
ments of  his  horse. — It  is  evident 
that  this  influence  must  be  principally 
exerted  through  the  Sympathetic  or 
Visceral  system  of  nerves,  since  a  large 
proportion  of  the  organs  on  which  it 
operates  are  supplied  by  no  other  :  and 
hence  this  apparatus  has  been  com- 
monly designated  the  l  Nervous  system 
of  organic  life/  as  distinguishing  it 
from  the  Cerebro-spinal  system,  which 
is  the  *  Nervous  system  of  animal  life.' 
There  is,  however,  no  such  parallelism 
between  them,  as  this  designation 
would  imply;  for  whilst  the  operations 
of  the  Cerebro-spinal  system  essentially 
constitute  the  Animal  life  of  the  indi- 
vidual, those  of  the  Sympathetic  can- 
not be  fairly  said  to  do  more  than  con- 
trol and  direct  those  of  Nutrition  and 
Secretion. — We  shall  now  enquire  in- 
to the  structure  and  relations  of  the 
Sympathetic  System;  and  shall  then 
examine  the  nature  of  the  actions 
which  there  seems  reason  to  attribute 
to  it. 

824.  Sympathetic  Nervous  System. 
— That  collection  of  scattered  but  mu- 
tually-connected ganglia  and  nerves, 
of  which  this  apparatus  is  made-up, 
may  be  ranged  under  the  following 
groups  : — 1.  The  isolated  ganglia  and 
nerves  in  immediate  connection  with 
the  Viscera,  which  seem  to  be  the 
chief  centres  of  the  system ;  these  form 

A  view  of  the  Great  Sympathetic  Nerve. — 1,  the  plexus  on  the  carotid  artery  in  the  carotid 
foramen ;  2,  sixth  nerve  (motor  externus);  3,  first  branch  of  the  fifth  or  ophthalmic  nerve; 
4,  a  branch  on  the  septum  narium  going  to  the  incisive  foramen;  5,  the  recurrent  branch  or 
vidian  nerve  dividing  into  the  carotid  and  petrosal  branches  ;  6,  posterior  palatine  branches  ; 
7,  the  lingual  nerve  joined  by  the  chorda  tympani;  8,  the  portio  dura  of  the  seventh  pair  or 
the  facial  nerve;  9,  the  superior  cervical  ganglion  ;  10,  the  middle  cervical  ganglion  ;  11,  the 
inferior  cervical  ganglion ;  12,  the  roots  of  the  great  splanchnic  nerve  arising  from  the  dorsal 
ganglia;  13,  the  lesser  splanchnic  nerve;  14,  the  renal  plexus;  15,  the  solar  p*lexus;  16,  the 
mesenteric  plexus  ;  17,  the  lumbar  ganglia;  18,  the  sacral  ganglia;  19,  the  vesical  plexus;  20, 
the  rectal  plexus;  21,  the  lumbar  plexus  (cerebro-spinal) ;  22,  the  rectum;  23,  the  bladder; 
24,  the  pubis ;  25,  the  crest  of  the  ilium  ;  26,.  the  kidney  ;  27,  the  aorta  ;  28,  the  diaphragm  ; 
29,  the  heart;  30,  the  larynx;  31,  the  submaxillary  gland:  32,  the  incisor  teeth;  33,  nasal 
septum;  34,  globe  of  the  eye;  35,  36,  cavity  of  the  cranium.] 


734 


INFLUENCE    OF    THE    NEKVOUS    SYSTEM 


three  principal  plexuses,  the  Cardiac,  the  Solar,  and  the  Hypogastric.     2.  The 
double  chain  of  Prevertebral  ganglia,  with  connecting  cords;  which  lies  in  front 


[FIG.  193. 


A  plan  of  the  branches  of  the  fifth  nerve,  modified  from  a  sketch  by  Sir  C.  Bell.  o.  Sub- 
maxillary  gland,  with  the  submaxillary  ganglion  above  it.  1.  Small  root  of  the  fifth  nerve, 
which  joins  the  lower  maxillary  division.  2.  Larger  root,  with  the  Gasserian  ganglion.  3. 
Ophthalmic  nerve.  4.  Upper  maxillary  nerve.  5.  Lower  maxillary  nerve.  6.  Chorda  tym- 
pani.  7.  Facial  nerve.] 

of  the  Vertebral,  column,  and  which  communicates  on  the  one  hand  with  th0 
Spinal  nerves,  and  on  the  other  with  the  before-named  plexuses.  Under  this 
head  we  should  probably  rank  the  minute  Cranial  ganglia,  which  are  situated  in 
the  neighbourhood  of  the  Organs  of  Sense,  and  in  immediate  connection  with  the 
branches  of  the  Fifth  pair  that  proceed  to  them ;  these  are  the  ophthalmic,  otic, 
spheno-palatine,  and  submaxillary  ganglia  (Fig.  193).  3.  The  ganglia  on  the  poste- 
rior roots  of  the  Spinal  nerves ;  under  which  head  we  are  probably  to  rank  not  only 
the  Gasserian  ganglion  of  the  Fifth  pair,  but  also  the  ganglia  near  the  roots  of  the 
Pneumogastric  and  Gllosso-pharyngeal  nerves. — The  trunks  of  the  Sympathetic 
are  made-up  of  different  orders  of  fibres ;  some  of  these  having  their  central  ter- 
mination in  the  vesicular  matter  of  the  Sympathetic  ganglia  themselves,  whilst 
Bothers  are  derived  from  the  Cerebro-spinal  system.  The  former,  which  are  all  of 
the  '  gelatinous'  kind,1  are  most  abundant  in  the  great  Visceral  plexuses;  but  they 
may  be  traced  from  the  prevertebral  ganglia  into  the  Spinal  nerves,  part  of  them 
proceeding  to  the  ganglia  on  their  posterior  roots  (whence  fibres  are  given-off  that 
mingle  with  their  spinal  fibres),  whilst  another  part  enter  the  anterior  roots  and 
mingle  with  their  fibres.  On  the  other  hand,  the  latter,  which  are  of  the  '  tubular' 
kind,  are  derived  by  the  same  cords  of  communication  (these  being  commonly 
termed  the  ' roots'  of  the  Sympathetic,  but  being  really  commissural  bands  that 

1  It  must  be  carefully  borne  in  mind,  that,  although  the  proper  Sympathetic  fibres  are 
all  '  gelatinous,'  yet  that  the  Cerebro-Spinal  system  contains  'gelatinous'  fibres  of  its  own, 
which  are  very  abundant  in  some  parts.  (See  PRINC.  or  GEN.  PHYS.,  Am.  EdJ 


ON    THE    ORGANIC    FUNCTIONS. 


735 


[Fio.  194. 


bring  the  two  systems  into  connection)  from  both  roots  of  the  Spinal  nerves,  and 
pass  through  the  prevertebral  ganglia  into  the  Sympathetic  system,  without  un- 
dergoing any  ostensible  change.  Thus 
it  appears  that  the  Cerebro-spinal  and 
Sympathetic  systems  interpenetrate  one 
another;  each  having  its  own  series 
of  ganglionic  centres,  and  of  trunks 
connected  with  them ;  but  each  system 
transmitting  its  fibres  into  the  trunks 
of  the  other,  so  as  to  be  peripherically 
distributed  with  their  ramifications. 

825.  The  distribution  of  the  princi- 
pal trunks  and  branches  of  the  Sym- 
pathetic system  may  be  concisely 
stated  as  follows  : — 1.  Those  of  the 
Cardiac  plexus  proceed  chiefly  to  the 
Heart  and  great  blood-vessels,  whence 
they  are  continued,  with  reinforce- 
ments derived-from  other  subdivisions, 
and  with  multitudes  of  minute  ganglia 
in  their  course,  along  the  ramifica- 
tions of  the  Vascular  system  through- 
out the  body,  embracing  them  as  ivy 
embraces  the  trunk  and  branches  of 
a  tree.  Those  of  the  Solar  plexus 
are  transmitted  in  part  to  the  mus- 
cular walls  of  the  Alimentary  canal, 
from  the  stomach  to  the  lower  end  of 
the  colon ;  in  part  to  the  principal 
arterial  branches  given-off  from  the 
aorta,  and  with  them  to  the  liver, 
pancreas,  spleen,  and  kidneys,  as  also 
to  the  testes  of  the  male  and  the  ova- 
ries of  the  female.  Those  of  the  Hy- 
pogastric.  plexus  supply  the  muscular 
walls  of  the  pelvic  viscera,  the  blad- 
der, urethra,  vagina  of  the  female, 
and  rectum ;  besides  sending  branches  to  the  bloodvessels  themselves. — 2.  The 
branches  of  the  Prevertebral  ganglia  of  the  trunk  for  the  most  part  contribute  to 
form  the  plexuses  just  described.  Those  of  the  neck,  however,  furnish  a  large  sup- 
ply to  the  carotid  artery,  round  which  they  form  a  plexus,  and  also  give-off  branches 
which  inosculate  with  those  of  the  Pneumogastric  to  form  the  pharyngeal  and 
laryngeal  plexuses ;  and  those  of  the  upper  part  of  the  thorax,  give-off  branches 
which  inosculate  with  those  of  the  Pneumogastric  to  form  the  pulmonary  plexus. 
Of  the  ophthalmic  ganglion  (§  492),  the  branches  are  distributed,  not  merely  to 
the  iris,  whose  radiating  fibres  are  made  to  contract  through  their  instrumentality, 
as  already  explained  (§  757) ;  but  also  the  vascular  apparatus  of  the  eyeball, 
and  especially  to  the  ciliary  processes,  which  seem  to  possess  a  sort  of  erectile 
character.  The  otic  ganglion,  which  communicates  with  the  third  division  of  the 
Fifth  pair,  and  with  the  Glosso-pharyngeal,  may  be  considered,  from  the  distri- 
bution of  most  of  its  branches  to  the  tensor  tympani  and  .cireumflexus  palati 
muscles,  as  ministering  to  the  exercise  of  the  sense  of  Hearing,  in  somewhat 
the  same  mode  that  the  ophthalmic  ganglion  seems  to  do  to  that  of  vision  (§  781). 
The  Spheno-palatine  ganglion  (Fig.  197),  whose  connections  are  with  the  Fifth  and 
the  Facial  nerves,  seems  in  like  manner  to  minister,  by  the  distribution  of  its 
branches  on  the  mucous  membrane  of  the  nasal  cavity  and  the  palate,  to  tLo 


Roots  of  a  dorsal  spinal  nerve,  and  its  union 
with  sympathetic:  c,  c.  Anterior  fissure  of  the 
spinal  cord.  a.  Anterior  root.  p.  Posterior  root, 
with  its  ganglion,  a'.  Anterior  branch,  p'.  Pos- 
terior branch.  «.  Sympathetic,  e.  Its  double 
junction  with  the  anterior  branch  of  the  spinal 
nerve  by  a  white  and  gray  filament.] 


736 


INFLUENCE    OF    THE    NERVOUS    SYSTEM 


[Fio.  195. 


senses  of  Smell  and  Taste.  Of  the  Submaxillary  ganglion,  which  also  is  chiefly 
connected  with  the  Fifth  and  the  Facial  nerves,  the  branches  proceed  almost  en- 
tirely to  the  Submaxillary  gland. — 3. 
The  fibres  which  arise  from  the  gan- 
glia on  the  posterior  roots  of  the  Spi- 
nal nerves  (if  really  belonging  to  the 
Sympathetic  system)  must  be  distri- 
buted along  with  the  branches  pro- 
ceeding from  the  trunks  which  they 
help  to  form ;  as  must  also  a  part  of 
those  fibres  which  are  sent  from  the 
proper  Sympathetic  ganglia  into  the 
roots  of  the  same  nerves,  a  large  part 
of  them,  however,  being  distributed 
upon  the  blood-vessels  of  the  Spinal 
Cord  itself. 

826.  If,  then,  it  be  enquired  what 
inferences  we  are  entitled  to  draw 
respecting  the  functions  of  the  Sym- 
pathetic system  of  nerves,  from  our 

A  representation  of  some  of  the  nerves  of  the  or-  knowledge  of  its  Anatomical  distribu- 
bit,  especially  to  show  the  lenticular  ganglion  (Ar-  tion,  we  are  at  Once  justified  in  reply- 
nold).  1.  Ganglion  of  the  fifth.  2.  Ophthalmic  ing,  that  a  large  proportion  of  the 
nerve.  3.  Upper  maxillary.  4.  Lower  maxillary.  Muscular  apparatus  which  directly 
5  Nasal  branch,  giving _the  long  root  to  the  lenti-  ministers  to  the  Organic  functions, 
cular  ganglion.  6.  Third  nerve.  7.  Inferior  ob-  -  ,  ,  .  (=  jr. 

lique  branch  of  the  third  connected  with  the  gan-  —  that>  namelJ>  *hich  surrounds  the 
glion  by  the  short  root.  8.  Optic  nerve.  9.  Sixth  alimentary  canal  from  the  stomach 
nerve.  10.  Sympathetic  on  the  carotid  artery.]  downwards,  with  the  gland-ducts 

which  open  into  it, — that,  also,  which 

forms  the  walls  of  the  bladder  and  uterus,  of  the  ureters  and  fallopian  tubes, — and 
that,  too,  which  governs  the  diameter  of  the  blood-vessels, — receives  no  other  nerv- 
ous supply  ;  and,  consequently,  that  of  whatever  motor  influence  these  parts  may 
receive  from  Mental  states  or  from  excitation  not  applied  to  themselves,  this 
system  of  nerves  must  be  the  channel.  The  same  may  be  said,  too,  in  regard  to 
that  greater  portion  of  the  Glandular  apparatus,  which  is  exclusively  supplied  by 
the  Sympathetic  nerve,  and  chiefly  by  the  plexuses  that  embrace  its  blood- 
vessels; since  any  such  alterations  in  its  rate  of  activity,  or  in  the  character  of 
its  products,  as  depend  upon  conditions  of  Mind,  can  be  brought-about  through 
no  other  instrumentality. — It  is  not  a  little  remarkable,  however,  that  those 
portions  of  the  Muscular  apparatus  of  Organic  life,  which  most  obviously  exhibit 
in  their  action  the  influence  of  the  Nervous  system,  both  in  their  respondence  to 
emotional  states,  and  in  their  sympathy  with  disturbance  in  other  functions, — 
namely  the  Heart  and  the  Stomach, — derive  a  considerable  part  of  their  nervous 
supply  directly  from  the  Cerebro-spinal  system.  And  it  is  still  more  significant,  that 
most  of  those  Glands  whose  function  is  occasional,  and  whose  states  of  activity 
are  most  obviously  influenced  by  affections  of  the  Mind,  are  specially  supplied  by 
Cerebro-spinal  nerves,  in  addition  to  the  Sympathetic  plexuses  which  they 
receive  on  the  walls  of  their  blood-vessels  :  thus,  the  Lachrymal  and  Salivary 
glands  are  supplied  with  branches  of  the  Fifth  and  Facial  nerves;  the  Mammary 
glands  by  branches  of  the  Intercostals ;  and  the  Gastric  glandulse  by  the  Pneumo- 
gastric.  It  cannot  but  be  deemed  highly  probable,  then,  from  this  circumstance 
alone,  that  the  influence  of  mental  states  upon  the  function  of  Secretion  may  be 
exerted  through  the  nerves  of  the  Cerebro-spinal  system,  as  well  as  through  those 
of  the  Sympathetic. 

827.  It  must  be  in  virtue  of  the  connections  of  the  Sympathetic  with  the 
Oerebro-spinal  system,  that  the  parts  which  are  solely  supplied  with  nerves  from 


ON    THE    ORGANIC    FUNCTIONS. 
[FiG.  196.  [Fie.  197. 


737 


Fig.  196. — The  otic  ganglion  seen  from  the  inner  side.  (From  Arnold.)  or.  Internal  ptery- 
goid  muscle.  6.  Carotid  artery  with  the  sympathetic,  c.  Mastoid  process,  d.  Membrane  of 
tympanum,  e.  Bones  of  tympanum.  1.  Gasserian  ganglion.  2.  First  division  of  fifth.  '6. 
Second  division.  4.  Third  division.  5.  Branch  to  tensor  palati.  6.  Small  superficial  petrosal 
nerve.  7.  Chorda  tympani.  The  nerve  of  the  internal  pterygoid  muscle  is  seen  on  the 
muscle.] 

Fig.  197.— A  view  of  the  olfactory  nerve,  and  of  Meckel's  ganglion  seen  from  the  inner  side. 
(From  Scarpa.)  a.  Elevator  muscle  of  the  soft  palate  thrown  down.  6.  Part  of  the  soft  palate, 
c.  Body  of  the  sphenoid  bone.  rf.  Internal  pterygoid  plate.  1.  Bulb  of  the  olfactory  nerves, 
giving  branches  over  the  upper  two  spongy  bones.  2.  Nasal  branch  of  the  ophthalmic  nerve. 
3.  Smaller  palatine  nerve.  4.  Meckel's  ganglion.  5.  Larger  palatine  nerve,  dividing  in  the 
roof  of  the  mouth.  6.  Vidian  nerve.  7.  External  palatine  nerve.] 

the  former,  are  capable  of  transmitting  sensory  impressions  to  the  Sensorium. 
It  is  true  that,  under  ordinary  circumstances,  these  parts  are  insensible ;  that  is, 
impressions  made  upon  them  do  not  travel  onwards  through  the  Spinal  Cord  to 
the  Encephalon :  but  their  sensibility  is  acutely  manifested  in  morbid  states,  in 
which  the  impressions  seem  to  be  propagated  further  than  usual,  in  virtue  of 
their  greater  potency.  That  it  is  the  office  of  the  ganglia  on  the  roots  of  the 
Spinal  nerves  to  "  cut-off  sensation,"  that  is,  to  prevent  the  further  transmission 
of  sensory  impressions,  is  an  old  doctrine ;  and  there  seems  much  reason  to  be- 
lieve that  this  may  be  effected  by  the  free  communication  between  one  fibre  and 
another,  which  is  established  through  the  vesicular  substance  of  a  ganglion,  so 
that  the  whole  force  of  ordinary  impressions  on  the  nerve-fibres  is  lost  in  diffu- 
sion among  the  rest  of  their  contents.  The  same  principle  seems  to  apply  to  the 
motor-fibres ;  for  there  are  cases  which  show  that  when  fibres  obviously  belonging 
to  Cerebro-spinal  nerves  pass  through  Sympathetic  ganglia,  they  do  not  so  rapidly 
or  so  surely  transmit  motor  impulses,  as  when  they  have  no  such  relation  to 
ganglia.1 

828.  Although  it  is  not  easy  to  obtain  definite  evidence  of  the  influence  of  the 
Sympathetic  system  on  Muscular  Contraction,  since  this  influence  is  extinguished 
within  a  short  time  after  death,  yet  it  has  been  established  by  the  elaborate  re- 
searches of  Prof.  Valentin  and  others  (§§  86,  240,  258),  that  contractions  of  the 
various  muscular  parts  supplied  by  the  three  great  Visceral  plexuses  may  bp  ox- 
cited  by  irritation  applied  to  their  nerves  and  ganglia.  But  Prof.  V.  has  further 
shown,  that  the  same  effects  may  be  produced  by  irritating  either  the  Preverte- 
bral  ganglia,  or  the  cords  of  communication  with  the  Spinal  nerves  which  have 
Deen  sometimes  called  the  '  roots  of  the  Sympathetic,  or  the  roots  of  the  Spinal 
nerves  themselves.  It  results  from  his  inquiries,  that,  although  any  particular 


1  See  Messrs.  Kirkee  and  Paget's 
47 


Handbook  of  Physiology,"  Am.  Ed.  p.  471. 


738  INFLUENCE    OF    THE    NERVOUS    SYSTEM 

division  of  the  Sympathetic  nerve  must  be  regarded  as  extremely  complex  in  its 
relations,  deriving  its  motor  fibres  from  many  different  sources,  the  ultimate  dis- 
tribution of  these  fibres  is  sufficiently  simple,  so  that  each  organ  is  definitely 
supplied  from  a  certain  part  of  the  Cerebro-spinal  axis.  But  the  fibres  proceed- 
ing from  the  roots  of  the  Cerebro-spinal  nerves  do  not  pass  into  the  nearest 
organs,  being  transmitted  through  three  or  more  of  the  prevertebral  ganglia  of 
the  Sympathetic,  before  reaching  their  ultimate  destination ;  thus  the  motor 
fibres  of  the  cardiac  plexus  are  principally  derived  from  the  cervical  portion  of 
the  Spinal  Cord,  those  of  the  solar  plexus  from  the  thoracic  region,  and  those  of 
the  hypogastric  plexus  from  the  dorsal  region.  So,  again,  we  have  seen  that  the 
dilatation  of  the  Pupil,  which  immediately  depends  on  the  instrumentality  of  the 
Sympathetic  nerve,  is  called-forth  also  by  irritation  of  the  roots  of  the  Spinal 
nerves  in  the  cervical  region  (§  757). 

829.  It  can  only  be  through  the  Nervous  System,  that  the  Muscular  apparatus 
of  Organic  life  is  acted-upon  by  states  of  Mind.  Although  no  exertion  of  the 
Will  can  produce  any  effect  upon  any  part  of  it,  yet  there  are  various  organs 
whose  muscular  walls  are  influenced  on  the  one  hand  by  Emotional  states,  and  on 
the  other  by  the  state  of  Expectant  Attention.  The  Heart  sympathizes  so  much 
with  the  emotions,  that  the  language  of  almost  all  civilized  nations  refers  to  it  as 
the  seat  of  the  '  feelings '  (§§  238,  239) ;  but  we  have  as  yet  no  certain  evidence, 
whether  this  influence  is  transmitted  through  the  Sympathetic  or  through  the 
Pneumogastric  nerve.  The  former  seems  the  more  probable  channel,  when  we 
bear  in  mind  that  it  can  be  through  the  Sympathetic  alone  that  those  alterations 
in  the  diameter  of  the  blood-vessels  take-place,  which  give-rise  to  the  blush  of 
modesty  or  shame,  or  to  the  pallor  which  alternates  with  this  in  many  states  of 
mental  agitation.1  So,  again,  the  influence  of  Emotional  states  is  strikingly 
manifested  in  the  production  of  the  peculiar  turgescence  of  the  Erectile  tissues 
(§  282) ;  and  here  we  have  a  striking  example  of  the  utter  powerlessness  of  the 
Will,  in  the  well-known  fact,  that  no  amount  of  sexual  desire  will  produce  erec- 
tion, if  the  mind  be  possessed  with  any  feeling  of  doubt  or  apprehension  as  to 
the  existence  of  the  sexual  ability.  The  muscular  walls  of  the  Alimentary  canal 
seem  frequently  to  be  excited  to  increased  action  by  agitating  emotions ;  but  it 
may  be  doubted  how  far  this  is  a  primary  effect  of  the  mental  state,  or  how  far 
it  is  consequent  upon  the  influence  of  that  state  upon  the  Secretions  poured  into 
the  canal  (§  832). — The  influence  of  the  state  of  expectant  attention,  as  of  the 
emotions,  is  strongly  manifested  in  the  case  of  the  Heart ;  the  action  of  which, 
as  Sir  H.  Holland  has  remarked,  "is  often  quickened  or  otherwise  disturbed  by 
the  mere  centering  the  consciousness  upon  it,  without  any  emotion  or  anxiety. 
On  occasions  where  its  beats  are  audible,  observation  will  give  proof  of  this,  or 
the  physician  can  very  often  infer  it  while  feeling  the  pulse ;  and  where  there  is 
liability  to  irregular  pulsation,  such  action  is  seemingly  brought-on,  or  increased, 
by  the  effort  of  attention,  even  though  no  obvious  emotion  be  present/'2  There 
can  be  no  doubt  that  the  movements  of  the  lower  part  of  the  Alimentary  Canal 
are  capable  of  being  affected  in  a  similar  manner;  since  we  may  frequently  trace 
the  rapid  descent  of  the  faecal  mass  into  the  rectum,  when  we  expect  to  be 
shortly  able  to  discharge  it ;  and  it  is  in  great  part  in  this  mode,  that  habit  ope- 
rates, in  producing  a  readiness  for  defecation  at  particular  times,  and  that  bread- 
pills  and  other  supposititious  purgatives  unload  the  bowels.3 

1  The  pallor  of  extreme  fear  or  terror  is  probably  due  rather  to  a  state  tending  to  Syn- 
cope, arising  from  a  partial  failure  of  the  Heart's  action. 

a  "Chapters  on  Mental  Physiology,"  p.  16. 

3  The  Author  may  mention  the  two  following  cases,  which  have  fallen  within  his  own 
knowledge,  as  curious  illustrations  of  the  influence  of  mental  states  upon  the  movements 
of  the  alimentary  canal. — The  first  of  these  occurred  in  the  person  of  a  literary  man,  of  a 
somewhat  hypochondriacal  temperament,  who  had  been  troubled  with  continual  costive- 
ness,  for  which  he  had  been  accustomed  to  take  an  aperient  pill  daily.  Finding  that  this 
ceased  to  have  its  usual  effect,  and  being  fearful  of  increasing  his  regular  dose,  he  applied 


ON    THE    ORGANIC    FUNCTIONS.  739 

830.  No,  experimental  evidence  has  yet  been  obtained,  that  the  proper  fibres 
of  the  Sympathetic  System,  have  any  power  of  exciting  muscular  contraction,  or 
that  its  ganglia  can  serve  as  centres  of  reflex  action  to  the  organs  which  they 
supply ;  on  the  contrary,  it  is  quite  certain  that  the  ganglia  on  the  posterior  roots 
of  the  Spinal  nerves  have  no  such  endowment.  And  as  all  the  facts  which  have  , 
been  supposed  to  indicate  the  existence  of  such  a  power,  may  be  otherwise  ex- 
plained in  accordance  with  our  fundamental  doctrine  (§§  86-87,  241-243),  there 
seems  to  be  no  ground  whatever  for  the  assumption  of  its  possession  by  these 
parts  of  the  apparatus. — If,  then,  the  sensori-motor  endowments  of  the  Sympa- 
thetic trunks  be  restricted  to  those  fibres  which  are  really  Cerebro-spinal  in  their 
origin  or  termination,  it  remains  to  inquire  what  are  the  functions  of  those  true 
Sympathetic  fibres,  whose  vesicular  centres  lie  in  the  ganglia  of  the  Sympathetic 
system.  Upon  this  point  we  can  only  surmise ;  but  there  appears  strong  ground 
for  the  conclusion,  that  the  office  of  these  fibres  is  to  produce  a  direct  influence 
upon  the  chemico-vital  processes  concerned  in  the  Organic  functions  of  nutrition, 
secretion,  &c. ;  an  influence  which,  although  not  essential  to  the  performance  of 
each  separate  act,  may  yet  be  required  to  harmonize  them  all  together,  and 
to  bring  them  into  connection  with  mental  states. — That  the  Nervous  system 
does  exert  such  an  agency,  will  be  presently  shown ;  and  reasons  have  already 
been  assigned,  for  regarding  the  Sympathetic  fibres  as,  in  certain  cases,  its  only 
possible  channel. 

831.  Turning,  now,  to  the  Cerebro-Spinal  system  of  nerves,  we  find  that  the 
exercise  of  a  powerful  influence  by  the  Pneumogastric  nerves,  over  the  secretion 
of  Gastric  fluid,  seems  to  have  been  conclusively  established  by  the  experimental 
researches  formerly  referred-to  (§§  101-102) ;  these  at  the  same  time  no  less 
clearly  proving  the  fact,  that  the  Secreting  process  is  essentially  independent-  of 
nervous  influence,  which  exerts  nothing  more  than  a  regulative  control  over  it 
(§  103).  *  The  recent  experiments  of  Ludwig,  made  with  a  view  to  determine  the 
influence  of  the  nerve-force  upon  the  Salivary  secretion,  seems  to  justify  a  like 
conclusion  in  regard  to  it.  For  he  has  found  that  section  of  the  Facial  nerve 
entirely  suspends  the  secretion  of  the  Parotid  gland,  save  in  so  far  as  this  is  kept- 

for  advice  to  a  practitioner,  who,  having  had  former  experience  of  what  Mental  agency 
alone  would  do,  determined  to  try  its  effect  in  this  instance.  Seating  his  patient  before 
him,  with  the  abdomen  uncovered,  he  desired  him  to  fix  his  attention  intently  upon  his 
abdominal  sensations,  and  assured  him  that  in  a  short  time  he  was  quite  certain  that  he 
would  begin  to  feel  a  movement  in  his  bowels,  which  would  end  in  a  copious  evacuation. 
He  himself  did  nothing  but  look  steadily  at  his  patient,  with  an  air  of  great  determination 
and  confidence,  and  point  his  finger  at  the  abdomen,  moving  it  along  the  arch  of  the  colon, 
and  (as  it  were)  in  the  course  of  the  convolutions  of  the  small  intestines,  80  as  to  aid  the 
patient  in  fixing  his  attention  upon  them.  In  a  short  time  the  expected  movements  were 
felt,  and  a  copious  evacuation  soon  followed  :  and  for  some  time  afterwards,  the  bowels 
continued  to  act  freely  without  medicine. — In  the  other  case,  a  Lecturer  at  a  public  Insti- 
tution was  seized  with  a  strong  impulse  to  defecation  during  his  lecture ;  and  was  greatly 
inconvenienced  by  the  effort  necessary  to  restrain  it.  Before  every  subsequent  lecture  in 
the  same  place,  the  same  impulse  returned  upon  him,  notwithstanding  that  he  might  have 
previously  unloaded  his  bowels  elsewhere.  In  this  case,  there  was  obviously  a  state  of 
apprehension  combined  with  the  simple  anticipation ;  but  the  influence  of  the  latter  is 
shown  by  the  fact,  that  in  no  other  place  did  this  individual  experience  the  impulse  in 
question  under  the  like  circumstances. 

1  It  is  remarkable  that  experimenters  so  accurate  as  Bidder  and  Schmidt  should  have 
even  been  led  to  doubt  by  the  results  of  their  experiments,  whether  the  Pneumogastric 
exerts  any  influence  on  the  Gastric  secretion ;  since  they  did  not  find  that  any  greater 
alteration  took-place,  either  in  the  quantity  or  the  quality  of  the  gastric  fluid,  in  the  case 
of  four  dogs  in  whose  stomachs  a  fistulous  orifice  had  been  established,  than  might  be  fairly 
attributed  to  the  shock  occasioned  by  the  severity  of  the  operation,  (See  their  "  Ver- 
daungssafte  und  Stoffwechsel,"  pp.  90-97.)  By  Volkmann,  moreover,  it  is  affirmed  that 
the  branches  of  the  Pneumogastric  distributed  on  the  stomach,  really  consist  of  Sympa- 
thetic filaments,  which  are  found  to  constitute  a  larger  and  larger  proportion  of  it,  and 
further  it  is  examined  from  its  point  of  exit  from  the  Cranium.  (See  Wagner's  "  Hand- 
worterbuch  der  Physiologie,"  band  ii.  p.  581.) 


740  INFLUENCE    OF    THE    NERVOUS    SYSTEM 

up  bv  the  indirect  action  of  the  Fifth  pair  and  of  the  Glossopharyngeal,  through 
the  stimulus  afforded  by  the  movements  of  mastication  and  deglutition  ;  whilst 
the  secretion  of  the  Sub-maxillary  gland  is  suspended  by  section  of  the  Fifth 
and  Facial,  this  being  a  direct  result  of  the  withdrawal  of  nervous  influence,  and 
not  being  merely  dependent  upon  the  absence  of  the  stimulus  afforded  by  the 
contractions  of  the  adjacent  muscles.' — It  seems  probable  from  these  experiments, 
and  from  the  phenomena  to  be  presently  adduced,  that  those  secreting  processes, 
which  (from  being  concerned  in  some  occasional  or  intermitting;  function,  instead 
of  forming  part  of  that  general  system  of  Excretory  actions  whose  uninterrupted 
continuance  is  essential  to  the  maintenance  of  the  normal  purity  of  the  blood, 
§  381)  only  take-place  at  certain  times,  or  in  consequence  of  definite  excitants, 
are  called  into  activity  by  the  instrumentality  of  the  nerves  which  supply  their 
respective  glands.  And  there  are  various  Pathological  phenomena,  which  indi- 
cate that  it  is  by  nervous  influence  that  the  mucous  secretion  covering  the  mem- 
branes is  caused  to  be  regularly  formed  for  their  protection  j  for,  when  this 
influence  is  interrupted  by  paralysis  of  the  nerves,  and  the  secretion  is  no  longer 
supplied,  the  membrane,  losing  its  protection,  is  irritated  by  the  air  or  the  fluids 
with  which  it  may  be  in  contact,  and  passes  into  an  inflammatory  condition. 
This  is  partly  the  explanation  of  the  fact,  now  well  ascertained,  that  the  eye 
is  liable  to  suppurate  when  the  Fifth  pair  has  been  divided ;  and  also  of  the 
frequent  occurrence  of  disease  of  the  mucous  membrane  of  the  bladder  in 
paraplegia. 

832.  The  influence  of  particular  conditions  of  the  Mind,  in  exciting,  suspend- 
ing, or  modifying  various  Secretions,  is  a  matter  of  daily  experience.  The 
Lachrymal  secretion,  for  example,  which  is  continually  being  formed  to  a  small 
extent  for  the  purpose  of  bathing  the  surface  of  the  eye,  is  poured-out  in  great 
abundance  under  the  moderate  excitement  of  the  emotions,  either  of  joy,  tender- 
ness, or  grief.  It  is  checked,  however,  by  violent  emotions ;  hence  in  intense 
grief,  the  tears  do  not  flow ;  and  it  is  a  well-known  indication  of  moderated  sor- 
row when  the  gush  takes  place,  this  very  act  affording  a  further  relief  (§  624). 
The  flow  of  Saliva,  again,  is  stimulated  by  the  sight,  the  smell,  the  taste,  or  even 
by  the  thought  of  food,  especially  of  such  as  is  of  a  savoury  character.  On  the 
other  hand,  violent  emotion  may  suspend  the  salivary  secretion ;  as  is  shown  by 
the  well-known  test,  often  resorted-to  in  India,  for  the  discovery  of  a  thief 
amongst  the  servants  of  a  family, — that  of  compelling  all  the  parties  to  hold  a 
certain  quantity  of  rice  in  the  mouth  during  a  few  minutes, — the  offender  being 
generally  distinguished  by  the  comparative  dryness  of  his  mouthful  at  the  end  of 
the  experiment.  There  is  much  reason  to  believe  that  the  secretion  of  Gastric 
fluid  is  affected,  in  the  same  manner  as  that  of  the  saliva,  by  the  impressions 
made  by  food  upon  the  senses ;  for  it  has  been  ascertained  by  Bidder  and  Schmidt 
(Op.  cit.  p.  35),  that  it  is  copiously  effused  into  the  stomachs  of  dogs  that  have 
been  kept  fasting,  when  flesh  or  any  other  attractive  food  is  placed  before  them. 
That  the  secretion  on  the  other  hand,  is  entirely  suspended  by  powerful  mental 
emotion,  seems  almost  certain,  from  the  well-known  influence  which  this  has  in 
dissipating  the  appetite  for  food,  and  in  suspending  the  digestive  process  when  in 
active  operation.  As  a  cheerful  state  of  feeling,  on  the  other  hand,  seems  to  be 
decidedly  favourable  to  the  performance  of  the  digestive  function,  it  probably  exerts 
a  beneficial  influence,  as  to  both  quantity  and  quality,  on  the  secretion  of  gastric 
fluid.  Of  the  influence  of  mental  states  on  other  secretions  concerned  in  the  reduc- 
tion and  appropriation  of  the  food  (such  as  the  Biliary,  Pancreatic,  and  Intestinal 
fluids),  neither  observation  nor  experiment  has  as  yet  afforded  any  satisfactory 
information.  It  is  a  prevalent,  and  perhaps  not  an  ill-founded  opinion,  that  mel- 
ancholy and  jealousy  have  a  tendency  to  increase  the  quantity,  and  to  vitiate  the 

1  For  the  very  ingenious  experiments  by  which  thefce  points  have  been  determined  by 
Ludwig  and  his  assistants,  Becher  and  Rahn,  see  "  Mittheilungen  der  Ziiurch.  Natur. 
Gesellschaft,"  No.  50,  and  "  Zeitschrift  fur  rat.  Med.,"  N.  F.,  band  i.  pp.  255-292. 


ON    THE    ORGANIC    FUNCTIONS.  741 

quality  of  the  Biliary  fluid.  Perhaps  the  disorder  of  the  organic  function  is 
more  commonly  the  source  of  the  former  emotion,  than  its  consequence;  hut  it  is 
certain  that  the  indulgence  of  these  feelings  produces  a  decidedly  morbific  effect 
by  disordering  the  digestive  processes,  and  thus  reacts  upon  the  nervous  system 
by  impairing  its  healthy  nutrition.  A  copious  secretion  of  foetid  gas  not  unfre- 
queutly  takes-place  in  the  intestinal  canal,  under  the  influence  of  any  disturbing 
emotion;  or  the  usual  fluid  secretions  from  its  walls  are  similarly  disordered. 
The  tendency  to  Defection  which  is  commonly  excited  under  such  circumstances, 
is  not,  therefore,  due  simply  to  the  relaxation  of  the  sphincter  ani  (as  commonly 
supposed) ;  but  is  partly  dependent  on  the  unusually-stimulating  character  of  the 
faeces  themselves.  The  same  may  be  said  of  the  tendency  to  Micturition,  which 
is  experienced  under  similar  conditions;  the  change  in  the  character  of  the 
Urine  becoming  preemptible  enough  among  many  animals,  in  which  it  acquires  a 
powerfully-disagreeable  odour  under  the  influence  of  fear,  and  thus  answers  the 
purpose  which  is  effected  in  others  by  a  peculiar  secretion.  The  halitus  from 
tke  Lungs  is  sometimes  almost  instantaneously  affected  by  bad  news,  so  as  to  pro- 
duce foetid  breath.  The  odoriferous  secretion  of  the  Skin,  which  is  much  more 
powerful  in  some  individuals  than  in  others,  is  increased  under  the  influence  of 
certain  mental  emotions  (as  fear  or  bashfulness),  and  commonly  also  by  sexual 
desire.  The  Sexual  secretions  themselves  are  strongly  influenced  by  the  con- 
dition of  the  mind.  When  it  is  frequently  and  strongly  directed  towards  objects 
of  passion,  these  secretions  are  increased  in  amount,  to  a  degree  which  may 
cause  them  to  be  a  very  injurious  drain  on  the  powers  of  the  system.  On  the 
other  hand,  the  active  employment  of  the  mental  and  bodily  powers  on  othei 
objects,  has  a  tendency  to  render  less  active,  or  even  to  check  altogether,  the 
processes  by  which  they  are  elaborated.1 

833.  No  Secretion  so  strongly  manifests  the  influence  of  the  Nervous  system, 
and  especially  of  Emotional  states,  both  upon  its  quantity  and  its  quality,  as  that 
of  the  Mammary  glands.  Although  the  production  of  Milk,  when  once  esta- 
blished, continually  goes-on  in  the  breasts  of  a  nursing  female,  yet  it  is  obviously 
accelerated  in  the  first  instance,  and  augmented  afterwards,  by  the  mechanical 
irritation  of  the  nipple  produced  by  the  suction  of  the  infant ;  and  this  alone  (or 
in  combination  with  the  strong  desire  to  furnish  milk)  has  been  effectual  in  pro- 
ducing the  secretion  in  girls  and  old  women,  and  even  in  men  (§  919).  Again, 
in  the  nursing  female,  the  secretion  is  often  suddenly  augmented  by  the  sight  of 
the  infant,  or  even  by  the  thought  of  him  in  absence,  especially  when  associated 
with  the  idea  of  suckling;  this  gives-rise  to  the  sudden  rush  of  blood  to  the 
gland,  which  is  known  by  nurses  as  the  draught,  and  which  may  probably  be 
attributed  to  a  dilatation  of  the  Mammary  arteries,  through  the  instrumentality 
of  their  Sympathetic  nerves,  analogous  to  that  which  takes-place  in  the  act  of 

1  This  is  a  simple  Physiological  fact,  but  of  high  moral  application.  The  Author 
would  say  to  those  of  his  younger  readers,  who  urge  the  wants  of  Nature  as  an  excuse  for 
the  illicit  gratification  of  the  sexual  passion,  "Try  the  effects  of  close  mental  application 
to  some  of  those  ennobling  pursuits  to  which  your  profession  introduces  you,  in  combina- 
tion with  vigorous  bodily  exercise  (for  the  effects  of  which  see  $  560),  before  you  assert 
that  the  appetite  is  unrestrainable,  and  act  upon  that  assertion."  Nothing  tends  so  much 
to  increase  the  desire,  as  the  continual  direction  of  the  mind  towards  the  objects  of  its 
gratification,  especially  under  the  favouring  influence  of  sedentary  habits ;  whilst  nothing 
so  effectually  represses  it,  as  the  determinate  exercise  of  the  mental  faculties  upon  other 
objects  ($  668),  and  the  expenditure  of  nervous  energy  in  other  channels  (g  624). — There 
seems  to  be  something  in  the  process  of  training  young  men  for  the  Medical  Profession, 
which  encourages  in  them  a  laxity  of  thought  and  expression  on  these  matters,  that  gene- 
rally ends  in  a  laxity  of  principle  and  of  action.  It  might  have  been  expected  that  those 
who  are  so  continually  witnessing  the  melancholy  consequences  of  the  violation  of  the 
Divine  law  in  this  particular,  would  be  the  last  to  break  it  themselves ;  but  this  is  unfor- 
tunately very  far  from  being  the  case.  The  Author  regrets  being  obliged  further  to  re- 
mark, that  some  works  which  have  issued  from  the  Medical  press,  contain  much  that  i? 
calculated  to  excite,  rather  than  to  repress,  the  propensity  ;  and  that  the  advice  sometime* 
given  by  practitioners  to  their  patients,  is  immoral  as  well  as  unscientific. 


742  INFLUENCE    OF    THE    NERVOUS    SYSTEM 

blushing  (§  829). — Although  we  are  continually  witnessing  indications  of  the 
powerful  influence  of  Emotional  states  upon  the  qualities  of  the  Mammary  secre- 
tion, yet  it  is  probable  that  such  influence  is  not  at  all  peculiar  to  the  milk ;  and 
that  we  only  recognize  it  more  readily  in  this  case,  because  the  digestive  system 
of  the  Infant  is  a  more  delicate  apparatus  for  testing  it,  than  any  which  the  Che- 
mist can  devise;  affording  proof,  by  disorder  of  its  function,  of  changes  in  the 
character  of  the  secretion,  which  no  examination  of  its  physical  properties  could 
detect.  The  following  remarks  on  this  subject  are  abridged  from  Sir  A.  Cooper's 
valuable  work  on  the  Breast.  "  The  secretion  of  milk  proceeds  best  in  a  tranquil 
state  of  mind,  and  with  a  cheerful  temper ;  then  the  milk  is  regularly  abundant, 
and  agrees  well  with  the  child.  On  the  contrary,  a  fretful  temper  lessens  the 
quantity  of  milk,  makes  it  thin  and  serous,  and  causes  it  to  disturb  the  child's 
bowels,  producing  intestinal  fever  and  much  griping.  Fits  of  anger  produce  a 
very  irritating  milk,  followed  by  griping  in  the  infant,  with  green  stools.  Grief 
has  a  great  influence  on  lactation,  and  consequently  upon  the  child.  The  loss  of 
a  near  and  dear  relation,  or  a  change  of  fortune,  will  often  so  much  diminish  the 
secretion  of  milk,  as  to  render  adventitious  aid  necessary  for  the  support  of  the 
child.  Anxiety  of  mind  diminishes  the  quantity,  and  alters  the  quality,  of  the 
milk.  The  reception  of  a  letter  which  leaves  the  mind  in  anxious  suspense,  les- 
sens the  draught,  and  the  breast  becomes  empty.  If  the  child  be  ill,  and  the 
mother  is  anxious  respecting  it,  she  complains  to  her  medical  attendant  that  she 
has  little  milk,  and  that  her  infant  is  griped  and  has  frequent  green  and  frothy 
motions.  Fear  has  a  powerful  influence  on  the  secretion  of  milk.  I  am  informed 
by  a  medical  man  who  practises  much  among  the  poor,  that  the  apprehension  of 
the  brutal  conduct  of  a  drunken  husband,  will  put  a  stop  for  a  time  to  the  secre- 
tion of  milk.  When  this  happens,  the  breast  feels  knotted  and  hard,  flaccid  from 
the  absence  of  milk,  and  that  which  is  secreted  is  highly  irritating;  and  some 
time  elapses  before  a  healthy  secretion  returns.  Terror,  which  is  sudden  and 
great  fear,  instantly  stops  this  secretion."  Of  this,  two  striking  instances,  in 
which  the  secretion,  although  previously  abundant,  was  completely  arrested  by 
this  emotion,  are  detailed  by  Sir  A.  C.  "  Those  passions  which  are  generally 
sources  of  pleasure,  and  which,  when  moderately  indulged,  are  conducive  to 
health,  will,  when  carried  to  excess,  alter,  and  even  entirely  check  the  secretion 
of  milk/' 

834.  There  is  even  evidence  that  the  Mammary  secretion  may  acquire  an 
actually  poisonous  character,  under  the  influence  of  violent  mental  excitement ; 
for  certain  phenomena  which  might  otherwise  be  regarded  in  no  other  light  than 
as  simple  coincidences,  appear  to  justify  this  inference,  when  interpreted  by  the 
less  striking  but  equally  decisive  facts  already  mentioned.  "  A  Carpenter  fell 
into  a  quarrel  with  a  Soldier  billeted  in  his  house,  and  was  set-upon  by  the  latter 
with  his  drawn  sword.  The  wife  of  the  Carpenter  at  first  trembled  from  fear 
and  terror,  and  then  suddenly  threw  herself  furiously  between  the  combatants, 
wrested  the  sword  from  the  soldier's  hand,  broke  it  in  pieces,  and  threw  it  away. 
During  the  tumult,  some  neighbours  came-in  and  separated  the  men.  While  in 
this  state  of  strong  excitement,  the  mother  took-up  her  child  from  the  cradle, 
where  it  lay  playing,  and  in  the  most  perfect  health,  never  having  had  a  mo- 
ment's illness ;  she  gave  it  the  breast,  and  in  so  doing  sealed  its  fate.  In  a  few 
minutes  the  infant  left-off  sucking,  became  restless,  panted,  and  sank  dead  upon 
its  mother's  bosom.  The  physician  who  was  instantly  called-in,  found  the  child 
lying  in  the  cradle,  as  if  asleep,  and  with  its  features  undisturbed ;  but  all  his 
resources  were  fruitless.  It  was  irrecoverably  gone."1  In  this  interesting  case, 

'  Dr.  Von  Ammon,  in  his  treatise  "Die  ersten  Mutterpflichten  und  die  erste  Kindes- 
pflege,"  quoted  in  Dr.  A.  Combe's  excellent  little  work  on  "  The  Management  of  Infancy." 
— Similar  facts  are  recorded  by  other  writers.  Mr.  Wardrop  mentions  ("Lancet,"  No. 
616),  that  having  removed  a  small  tumour  from  behind  the  ear  of  a  mother,  all  went  well, 
antil  she  fell  into  a  violent  passion ;  and  the  child,  being  suckled  soon  afterwards,  died  in 


ON    THE    ORGANIC    FUNCTIONS.  743 

the  milk  must  have  undergone  a  change  which  gave  it  a  powerful  sedative  action 
upon  the  susceptible  nervous  system  of  the  infant, — The  following,  which  oc- 
curred within  the  Author's  own  knowledge,  is  perhaps  equally  valuable  to  the 
Physiologist,  as  an  example  of  the  similarly-fatal  influence  of  undue  emotion  of 
a  different  character  ;  and  both  should  serve  as  a  salutary  warning  to  mothers, 
not  to  indulge  either  in  the  exciting  or  in  the  depressing  passions.  A  Lady  hav- 
ing several  children,  of  which  none  had  manifested  any  particulor  tendency  to 
cerebral  disease,  and  of  which  the  youngest  was  a  healthy  infant  a  few  months' 
old,  heard  of  the  death  (from  acute  hydrocephalus)  of  the  infant  child  of  a  friend 
residing  at  a  distance,  with  whom  she  had  been  on  terms  of  close  intimacy,  and 
whose  family  had  increased  almost  contemporaneously  with  her  own.  The  cir- 
cumstance naturally  made  a  strong  impression  on  her  mind ;  and  she  dwelt  upon 
it  the  more,  perhaps,  as  she  happened,  at  that  period,  to  be  separated  from  the 
rest  of  her  family,  and  to  be  much  alone  with  her  babe.  One  morning,  shortly 
after  having  nursed  it,  she  laid  the  infant  in  its  cradle,  asleep  and  apparently  in 
perfect  health;  her  attention  was  shortly  attracted  to  it  by  a  noise;  and,  on  going 
to  the  cradle,  she  found  her  infant  in  a  convulsion,  which  lasted  a  few  moments 
and  then  left  it  dead.  Now,  although  the  influence  of  the  mental  emotion  is 
less  unequivocally  displayed  in  this  case  than  in  the  last,  it  can  scarcely  be  a 
matter  of  doubt ;  since  it  is  natural  that  no  feeling  should  be  stronger  in  the 
mother's  mind  under  such  circumstances,  than  the  fear  that  her  own  beloved 
child  should  be  taken  from  her,  as  that  of  her  friend  had  been ;  and  it  is  probable 
that  she  had  been  particularly  dwelling  on  it,  at  the  time  of  nursing  the  infant 
on  that  morning. — Another  instance,  in  which  the  maternal  influence  was  less 
certain,  but  in  which  it  was  not  improbably  the  immediate  cause  of  the  fatal 
termination,  occurred  in  a  family  nearly  related  to  the  Author's.  The  mother 
had  lost  several  children  in  early  infancy,  from  a  convulsive  disorder ;  one  infant, 
however,  survived  the  usually-fatal  period;  but  whilst  nursing  him  one  morning, 
she  had  been  strongly  dwelling  on  the  fear  of  losing  him  also,  although  he  ap- 
peared a  very  healthy  child.  In  a  few  minutes  after  the  infant  had  been  trans- 
ferred into  the  arms  of  the  nurse,  and  whilst  she  was  urging  her  mistress  to  take 
a  more  cheerful  view,  directing  her  attention  to  his  thriving  appearance,  he  was 
se  zed  with  a  convulsion-fit,  and  died  almost  instantly.  Now  although  there  was 
here  unquestionably  a  predisposing  cause,  of  which  there  is  no  evidence  in  the 
other  cases,  it  can  scarcely  be  doubted  that  the  exciting  cause  of  the  fatal  disorder 
is  to  be  referred  to  the  mother's  anxiety.  This  case  offers  a  valuable  suggestion, 
— which,  indeed,  would  be  afforded  by  other  considerations, — that  an  infant,  under 
such  circumstances  should  not  be  nursed  by  its  mother,  but  by  another  woman 
of  placid  temperament,  who  has  reared  healthy  children  of  her  own. 

835.  The  influence  of  the  Nervous  System  upon  those  formati\e  processes 
which  constitute  the  function  of  Nutrition,  is  less  evident  than  it  is  upon  the  Se- 
cretory operations;  and  the  nature  of  this  influence  is  rather  to  be  interred  from 
the  results  of  its  withdrawal,  than  to  be  demonstrated  in  any  more  direct  manner. 
These  results  are  chiefly  to  be  seen  in  the  altered  nutrition  of  parts  exposed  to 
external  impressions,  as  the  integuments  generally,  but  particularly  those  of  the 
extremities ;  and  they  may  be  generally  expressed  by  the  statement,  that  the 
withdrawal  of  nervous  influence  from  a  part,  renders  it  less  able  to  withstand  the 
destructive  influence  of  physical  agencies.  It  has  been  clearly  shown,  however, 
by  the  careful  experiments  of  M.  Brown-Sequard  (§  501),  that  a  great  part  of  the 

convulsions.  He  was  sent-for  hastily  to  see  another  child  in  convulsions,  after  taking  the 
breast  of  a  nurse  who  had  just  been  severely  reprimanded ;  and  he  was  informed  by  Sir 
Richard  Croft,  that  he  had  seen  many  similar  instances.  Three  others  are  recorded  by 
Burdach  (Physiologic,"  $  522) ;  in  one  of  them,  the  infant  was  seized  with  convulsions  oo- 
the  right  side  and  hemiplegia  on  the  left,  on  sucking  immediately  after  its  mother  had  met 
with  .some  distressing  occurrence.  Another  case  was  that  of  a  puppy,  which  was  seized 
with  epileptic  convulsions,  on  sucking  its  mother  after  a  fit  of  rage. 


74-1  INFLUENCE     OF    THE    NERVOUS    SYSTEM 

injurious  effects  which  may  be  observed  to  follow  injuries  of  the  nerves  of  the 
extremities,  experimentally  inflicted,  are  traceable  to  want  of  power  on  the  part 
of  the  animal  (consequent  upon  the  paralysed  state  of  the  limbs)  to  withdraw 
them  from  irritating  impressions ;  and  must  not  be  attributed  to  any  deteriora- 
tion of  the  formative  operations,  directly  resulting  from  the  withdrawal  of  ner- 
vous agency.     The  following  case,  however,  which  is  given  by  Mr.  Paget '  on  the 
authority  of  Mr.  Hilton,  seems  more  unequivocally  to  establish  this  connexion. 
44  A  man  was  at  Guy's  Hospital,  several  years  ago,  who,  in  consequence  of  a  frac- 
ture at  the  lower  end  of  the  radius,  repaired  by  an  excessive  quantity  of  new 
bone,    suffered  compression  of  the   median   nerve.     He  had   ulceratiou  of  the 
thumb,  and  of  the  fore  and  middle  fingers,  which  had  resisted  various  treatment, 
and  was  cured  only  by  so  binding  the  wrist,  that  the  parts  on  the  palmar  aspect 
being  relaxed,  the  pressure  on  the  nerve  was  removed.     So  long  as  this  was  done, 
the  ulcers  became  and  remained  well ;  but  as  soon  as  the  man  was  allowed  to  use 
his  hand,  the  pressure  on  the  nerve  was  removed,  and  the  ulceration  in  the  parts 
supplied   by  it   returned."     Mr.   Paget  (Op.   cit.),   also  mentions  the  follow- 
ing curious  case.     "  A  lady  who  is  subject  to  attacks  of  what  are  called  nervous 
headaches,  always  finds  next  morning  that  some  patches  of  her  hair  are  white,  as 
if  powdered  with  starch.     The  change  is  effected  in  a  night ;  and  in  a  few  days 
after,  the  hairs  gradually  regain  their  dark  brownish  colour."     That  such  effects 
are  rather  to  be  attributed  to  the  loss  or  perversion  of  the  influence  of  the  Sym- 
pathetic system,  than  to  that  of  the  Cerebro-spinal,  would  appear  from  the  fact 
noticed  by  Magendie  and  Longet,  that  destructive  inflammation  of  the  eye  ensues 
more  quickly  after  division  of  the  Fifth  pair  in  front  of  the  Gasserian  ganglion, 
than  when  the  division  is  made  through  the  roots  of  the  nerve,  between  that 
ganglion  and  the  brain ;  the  Sympathetic  filaments  which  exist  largely  in  this 
nerve,  being  interrupted  in  their  course  to  the  tissues  in  the  former  case,  but  not 
in  the  latter.     So  Dr.  Axmann  found,  that  when  the  Spinal  nerves  of  Frogs  were 
divided  in  front  of  their  Prevertebral  ganglia,  the  nutrition  of  the  parts  supplied 
by  them  was  much  more  injuriously  affected,  than  it  was  when  the  section  was 
made  between  these  ganglia  and  the  Spinal  Cord.     And  this  inference  is  further 
supported  by  the  general  result  of  observation,  that  atrophy  of  parts  supplied  by 
the  Spinal  nerves  is  much  greater  when  the  sensory  (gangliated)  as  well  as  the 
motor  roots  are  involved,  than  when  the  latter  alone  are  paralysed  (Paget,  Op. 
cit.). 

836.  There  is  abundant  evidence  that  a  sudden  and  violent  excitement  of  some 
depressing  Emotion,  especially  Terror,  may  produce  a  severe  and  even  a  fatal 
disturbance  of  the  Organic  functions ;  with  general  symptoms  (as  Guislain  2  has 
remarked)  so  strongly  resembling  those  of  sedative  Poisoning,  as  to  make  it 
highly  probable  that  the  Hood  is  directly  affected  by  the  Emotional  state,  through 
Nervous  agency  j  and,  in  fact,  the  emotional  alteration  of  various  secretions,  just 
alluded-to  (§§  832-834),  seems  much  more  probably  attributable  to  some  such 
affection  of  the  blood,  than  to  a  primary  disturbance  of  the  secreting  process 
itself.  Although  there  can  be  no  doubt  that  the  habitual  state  of  the  Emotional 
sensibility  has  an  important  influence  upon  the  general  activity  and  perfection  of 
the  Nutritive  processes, — as  is  shown  by  the  well-nourished  appearance  usually 
exhibited  by  those  who  are  free  from  mental  anxiety  as  well  as  from  bodily  ail- 
ment, contrasted  with  the  "  lean  and  hungry  look  "  of  those  who  are  a  prey  to 
continual  disquietude, — yet  it  is  not  often  that  we  have  the  opportunity  of  ob- 
serving the  production  of  change  in  the  nutrition  of  any  specific  part,  by  strong 
emotional  excitement.  In  the  two  following  cases,  the  correspondence  of  the 
effects  to  their  alleged  causes  may  have  been  only  casual ;  and  a  much  larger 
collection  of  facts  would  be  needed  to  establish  the  rationale  here  advanced  as 

1  "  Lectures  on  Surgical  Pathology." 

2  "  Le9ons  Orales  sur  les  Phrenopathies,"  torn.  iii.  pp.  165-168. 


ON    THE    ORGANIC    FUNCTIONS.  745 

probable.  But  so  many  analogous  though  less  strongly-marked  phenomena  are 
presented  in  the  records  of  medical  experience,  and  the  influence  of  the  Emotions 
upon  the  products  of  Secretion  is  so  confirmatory,  that  there  does  not  seem  any 
reasonable  ground  for  hesitation,  in  admitting;  that  the  same  explanation  may 
apply  here  also.  The  first  of  these  cases,  cited  by  Guislain  (loc.  cit.)  from  Ri- 
dard,  is  that  of  a  woman  who,  after  seeing  her  daughter  violently  beaten,  was 
seized  with  great  terror,  and  suddenly  became  affected  with  gangrenous  erysipelas 
of  the  right  breast.  But  a  still  more  remarkable  example  of  local  disorder  of 
nutrition,  occasioned  by  powerful  emotion,  and  determined  as  to  its  seat  by  the 
intense  direction  of  the  attention  to  a  particular  part  of  the  body,  is  narrated  by 
Mr.  Carter.2  "  A  lady,  who  was  watching  her  little  child  at  play,  saw  a  heavy 
window-sash  fall  upon  its  hand,  cutting  off  three  of  the  fingers ;  and  she  was  so 
much  overcome  by  fright  and  distress,  as  to  be  unable  to  render  it  any  assistance. 
A  surgeon  was  speedily  obtained,  who,  having  dressed  the  wounds,  turned  him- 
self to  the  mother,  whom  he  found  seated,  moaning,  and  complaining  of  pain  in 
her  hand.  On  examination,  three  fingers,  corresponding  to  those  injured  in  the 
child,  were  discovered  to  be  swollen  and  inflamed,  although  they  had  ailed  nothing 
prior  to  the  accident.  In  four-and-twenty  hours,  incisions  were  made  into  them, 
and  pus  was  evacuated  ;  sloughs  were  afterwards  discharged,'  and  the  wounds 
ultimately  healed." 

837.  The  influence  of  the  state  of  expectant  attention,  in  modifying  the  pro- 
cesses of  Nutrition  and  Secretion,  is  not  less  remarkable  than  we  have  already 
seen  it  to  be  in  the  production  or  modification  of  Muscular  movements  (§§  659, 
829).  It  seems  certain  that  the  simple  direction  of  the  consciousness  to  a  part, 
independently  of  emotional  excitement,  but  with  the  expectation  that  some 
change  will  take-place  in  its  organic  activity,  is  often  sufficient  to  induce  such  an 
alteration,  and  would  probably  always  do  so,  if  the  concentration  of  the  attention 
were  sufficient.  The  most  satisfactory  exemplification  of  this  principle  has  been 
given  by  the  experiments  of  Mr.  Braid,  who  has  succeeded  in  producing  very 
decided  changes  in  the  secretions  of  particular  organs,  by  the  fixation  of  the  atten- 
tion upon  them  in  the  '  hypnotic '  state  (§  694).  Thus  he  brought-back  an  abun- 
dant flow  of  milk  to  the  breast  of  a  female  who  was  leaving-off  nursing  from 
defect  of  milk,  and  repeated  the  operation  upon  the  other  breast  a  few  days  sub- 
sequently, after  which  the  supply  was  abundant  for  nine  months;  and  in  another 
instance  he  induced  the  catamenial  flow  on  several  successive  occasions,  when  the 
usual  time  of  its  appearance  had  passed.  It  is  not  requisite,  however,  to  produce 
the  state  of  Somnambulism  for  this  purpose,  if  the  attention  can  be  sufficiently 
drawn  to  the  subject  in  any  other  mode;  thus  Mr.  Braid  has  repeatedly  produced 
the  last-named  result  on  a  female  who  possessed  considerable  power  of  mental 
concentration,  by  inducing  her  to  fix  her  thoughts  upon  it  for  ten  or  fifteen 
minutes,  so  as  to  bring-on  a  state  of  Abstraction.2 — Now  the  effects  which  are  pro- 
ducible by  this  voluntary  or  determinate  direction  of  the  consciousness  to  the 
result,  are  doubtless  no  less  producible  by  that  involuntary  fixation  of  the  atten- 
tion upon  it,  which  is  consequent  upon  the  eager  expectation  of  benefit  from 
some  curative  method  in  which  implicit  confidence  is  placed.  It  is  to  such  a 
state  that  we  may  fairly  attribute  most,  if  not  all,  the  cures,  which  have  been 
w  >rked  through  what  is  popularly  termed  the  'imagination.'  The  cures  are  real 
facts,  however  they  may  be  explained ;  and  there  is  scarcely  a  malady  in  which 
amendment  has  not  been  produced,  not  merely  in  the  estimation  of  the  patient, 
but  in  the  more  trustworthy  opinion  of  medical  observers,  by  practices  which  can 
have  had  no  other  effect  than  to  direct  the  attention  of  the  sufferer  to  the  part, 
and  to  keep  alive  his  confident  expectation  of  the  cure.  The  '  charming-away '  of 

1  "  On  the  Pathology  and  Treatment  of  Hysteria,"  p.  24. 

2  See  his  important  Memoir  on  '  Hypnotic  Therapeutics,'  in  "  Edinb.  Monthly  Journal," 
July,  1858. — Of  the  reality  of  this  last  result,  the  Author  has  had  an  opportunity,  through 
Mr.  Braid's  kindness,  of  perfectly  satisfying  himself. 


746  OF    GENERATION. 

warts  by  spells  of  the  most  vulgar  kind,  the  imposition  of  royal  hands  for  the 
cure  of  the  '  evil,  the  pawings  and  strokings  of  Valentine  Greatrakes,  the  manipu- 
lations practised  with  the  '  metallic  tractors/1  the  invocations  of  Prince  Hohen- 
lohe,  et  hoc  genus  omne, — not  omitting  the  globulistic  administrations  of  the 
Infinitesimal  doctors,  and  the  manipulations  of  the  Mesmerists,  of  our  own  times, 
— have  all  worked  to  the  same  end,  and  have  all  been  alike  successful.  It  is  un- 
questionable that,  in  all  such  cases,  the  benefit  derived  is  in  direct  proportion  to 
the  faith  of  the  suiferer  in  the  means  employed ;  and  thus  we  see  that  a  couple 
of  bread  pills  will  produce  copious  purgation,  and  a  dose  of  red  poppy  syrup  will 
serve  as  a  powerful  narcotic,  if  the  patient  have  entertained  a  sufficiently-confident 
expectation  of  such  results. 

838.  This  state  of  confident  expectation,  however,  may  operate  for  evil,  no 
less  than  for  good.  A  fixed  belief  that  a  mortal  disease  had  seized  upon  the 
frame,,  or  that  a  particular  operation  or  system  of  treatment  would  prove  unsuc- 
cessful, has  been  in  numerous  instances  (there  is  no  reason  to  doubt)  the  direct 
cause  of  a  fatal  result.  Thus  M.  Ridard  relates  the  case  of  a  man,  thirty  years 
of  age,  who  was  affected  with  stone  in  the  bladder,  and  who  saw  a  patient  die  by 
his  side,  after  being  operated-upon  for  the  same  complaint.  The  man's  imagina- 
tion became  excited ;  his  thoughts  were  constantly  fixed  upon  the  operation  which 
he  himself  expected  to  undergo,  and  upon  the  probable  death  that  would  follow ; 
and,  in  fact,  without  any  operation  at  all,  he  died  at  the  end  of  a  month,  affected 
with  gangrene  both  of  penis  and  scrotum.  Hence  also  it  is,  that  the  morbid 
feelings  of  the  Hypochondriac,  who  is  constantly  directing  his  attention  to  his 
own  fancied  ailments,  tend  to  induce  real  disorder  in  the  action  of  the  organs 
which  are  supposed  to  be  affected. — In  the  same  category,  too,  may  be  placed 
those  instances  (to  which  alone  any  value  is  to  be  attached),  wherein  a  strong 
and  persistent  impression  upon  the  mind  of  a  Mother,  has  appeared  to  produce 
a  corresponding  effect  upon  the  development  of  the  foetus  in  utero  (§  883).  In 
this  case,  the  effect  (if  admitted  to  be  really  exerted)  must  be  produced  upon 
the  maternal  blood,  and  transmitted  through  it  to  the  foetus;  since  there  is  no 
nervous  communication  between  the  parent  and  the  offspring.  There  is  no  diffi- 
culty, however,  in  understanding  how  this  may  occur  after  what  has  been  already 
stated  (§  217)  of  the  influence  of  minute  alterations  in  the  Blood,  in  determining 
local  alterations  of  nutrition. 


CHAPTER  XVI. 

OF    GENERATION. 
1. —  General  Character  of  the  Function. 

839.  HAVING  now  passed  in  review  the  various  operations  which  are  concerned 
in  maintaining  the  life  of  the  individual,  we  have  next  to  proceed  to  those  which 
are  destined  to  the  perpetuation  of  the  race,  by  the  production  of  successive 
generations  of  similar  beings.  Among  Plants,  and  the  lower  tribes  of  Animals, 
a  multiplication  of  independent  beings  takes-place  without  any  sexual  process 
whatever,  by  a  process  of  gemmation  or  *  budding '  from  the  parent-stock ;  these 
'  buds/  at  first  entirely  nourished  by  it,  gradually  become  less  and  less  dependent 
upon  it,  and  at  last  detach  themselves  and  maintain  a  separate  existence.  Now 

1  Dr.  Haygarth  of  Bath  (in  conjunction  with  Mr.  Richard  Smith  of  Bristol)  tested  the 
value  of'  Perkins's  metallic  tractors,'  by  substituting  two  pieces  of  wood  painted  in  imita- 
tion of  them,  or  even  a  pair  of  tenpenny  nails  disguised  with  sealing-wax,  or  a  couple  of 
Blate-pencils ;  which  they  found  to  possess  all  the  virtues  that  were  claimed  for  the  real 
Instruments. 


OF    THE    TESTES    AND    SEMINAL    FLUID.  747 

this  process  may  be  regarded  as  essentially  the  same  with  that  of  the  multipli- 
cation of  cells  by  subdivision,  which  is  one  of  the  most  ordinary  operations  of 
growth  and  development ;  and  it  is  peculiar  in  nothing  else  than  this, — that  the 
newly-formed  structure,  instead  of  remaining  as  a  constituent  and  dependent  part 
of  the  parental  fabric,  is  capable  of  living  independently  of  it,  and  of  thus  existing 
as  a  distinct  individual  when  spontaneously  or  artificially  detached.  Among  the 
higher  tribes  of  Animals,  as  in  Man,  this  mode  of  reproduction,  which  is  merely 
a  multiplication  of  the  individual,  and  not  a  real  Generative  process,  does  not 
present  itself,  at  least  in  the  adult  state ;  for  in  no  instance  do  we  find  that  a 
part  of  the  body  separated  from  the  rest  can  develope  the  organs  which  are 
necessary  for  the  sustenance  of  its  existence ;  and  the  power  which  the  organism 
possesses,  of  regenerating  parts  which  it  has  lost  by  disease  or  accident,  is  re- 
strained within  very  narrow  limits  (§  359).  But  there  is  good  ground  to  believe, 
that  such  a  multiplication  by  subdivision  may  take  place  at  that  earliest  period 
of  embryonic  life,  at  which  the  germ  is  nothing  else  than  a  mass  of  cells,  wherein 
no  distinction  of  parts  has  as  yet  manifested  itself;  and  that  the  production  of 
two  complete  individuals,  held-together  only  by  a  connecting  band,  may  arise 
from  some  cause  which  determines  the  subdivision  of  the  germinal  mass,  at  the 
period  when  its  grade  of  development  corresponds  with  that  of  the  Hydra  or 
Planaria  (§  355).  And  this  view  of  the  case  is  confirmed  by  the  facts  already 
stated  (§  359)  in  regard  to  the  higher  degree  of  the  regenerating  power  during 
embryonic  life,  infancy,  and  childhood,  as  compared  with  that  which  remains 
after  the  development  of  the  fabric  has  been  completed. 

840.  The  proper  act  of  Generation  in  Man,  as  in  the  Animal  and  Vegetable 
Kingdoms  generally  (seePniNC.  OF  OOMP.  PHYS.,  Chap.  XL,  Am.  Ed,),  uniformly 
involves  the  union  of  the  contents  of  two  peculiar  cells,  which  may  be  designated 
as  the  'sperm-cell/  and  the  'gerin-cell;  and,  as  in  all  higher  Animals,  the  'sperm- 
celP  developes  in  its  interior  a  self-moving  spermatozoon;  whilst  the  'germ-cell* 
(germinal  vesicle)  whose  contents  are  fertilized  by  the  spermatozoon,  is  imbedded  in 
a  mass  of  yolk  destined  for  the  early  nutrition  of  the  embryo  thence  originating;  so 
that  this  embryo,  if  supplied  with  the  requisite  warmth,  as  well  as  drawing  into 
itself  the  aliment  stored-up  for  it,  gradually  evolves  itself  into  the  likeness  of  its 
parent.  There  is  a  great  difference,  however,  among  the  different  tribes  of  Animals, 
as  to  the  degree  of  assistance  thus  afforded  to  the  embryo ;  the  general  rule  being, 
tha-t  the  higher  the  form  which  the  embryo  is  ultimately  to  attain,  the  longer  is  it 
supported  by  its  parent.  Hence  we  find  the  embryos  of  most  Invertebrated  ani- 
mals coming- forth  from  the  egg  in  a  condition  very  unlike  their  perfect  type,  and 
only  acquiring  this  after  a  long  succession  of  subsequent  alterations,  which  fre- 
quently involve  a  complete  change  of  form,  or  metamorphosis.  In  Fishes,  how- 
ever, the  embryo,  though  far  from  having  completed  its  embryonic  development 
at  the  time  of  its  emersion  from  the  egg,  does  not  differ  so  widely  from  the  adult 
type.  In  Birds,  there  is  a  provision  for  a  much  more  advanced  development ;  the 
store  of  nutritious  matter,  or  '  yolk/  being  so  large  as  to  allow  the  whole  series 
of  changes  requisite  for  the  formation  of  the  complete  chick,  to  take-place  before 
it  leaves  the  egg.  In  the  Mammalia,  on  the  contrary,  the  quantity  of  yolk  con- 
tained in  the  ovum  is  very  small,  but  the  embryo  is  only  dependent  upon  it  for 
the  materials  of  its  increase  during  the  earliest  stages  of  its  evolution  ;  for  it 
speedily  forms  a  special  connection  with  the  parent-structure,  by  means  of  which 
it  is  enabled  to  receive  a  continual  supply  of  newly-prepared  aliment,  so  as  to  be 
supported  at  the  expense  of  this  until  far  advanced  in  its  development.  Some 
approaches  to  this  arrangement  are  met- with  among  certain  of  the  lower  Animals, 
but  it  is  only  in  the  higher  Mammalia  that  it  is  completely  carried-out;  and  it 
is  only  in  this  class,  too,  that  we  find  a  supplemental  provision  for  the  nutrition 
of  the  offspring  after  it  has  come  forth  into  the  world.  In  many  of  the  lower 
tribes  of  Animals,  the  fertilization  of  the  ova  is  accomplished  without  any  sexual 
congress ;  the  spermatic  fluid  effused  by  the  male,  coming  into  direct  contact  with 


748 


OF  GENERATION:  —  ACTION   OF  THE  MALE. 


the  ova  previously  deposited  by  the  female  ;  but  in  all  the  higher  tribes,  as  in 
Man,  the  spermatic  fluid  is  conveyed  into  the  oviducts  of  the  female,  so  as  to 
impregnate  the  ovum  shortly  after  it  has  quitted  the  ovarium,  or  even  before  its 
final  escape  from  it 


198. 


2.  —  Action  of  the  Male. 

841.  The  Spermatic  fluid  of  the  Male  is  secreted  by  glandular  organs,  known 
as  Testes.  Each  of  these  consists  of  several  lobules,  which  are  separated  from 
each  other  by  processes  of  the  Tunica  Albuginea  that  pass  down  between  them, 
and  also  by  an  extremely  delicate  membrane  (described  by  Sir  A.  Cooper  under 
the  name  of  Tunica  Vasculosa)  consisting  of  minute  ramifications  of  the  sper- 
matic blood-vessels  united  by  areolar  tissue.  Each  lobule  (Fig.  198,  1  1)  is 
composed  of  a  mass  of  convoluted  tubuli  seminiferi,  throughout  which  blood- 

vessels are  minutely  distributed.  The 
lobules  differ  greatly  in  size,  some 
containing  one,  and  others  many  of 
the  tubuli  ;  the  total  number  of  the 
lobules  is  estimated  at  about  450  in 
each  testis,  and  that  of  the  tubuli  at 
840.  The  walls  of  the  tubuli  are 
firmer  than  those  of  similar  gland- 
canals  elsewhere;  for  outside  the 
basement-membrane  on  which  the 
epithelium  rests,  they  have  a  tolera- 
bly-firm but  extensible  envelope, 
composed  of  an  indistinctly-fibrous 
connective  tissue  with  longitudinal 
nuclei.  Their  convolutions  are  so 
arranged,  that  each  lobule  forms  a 
sort  of  cone,  the  apex  of  which  is 
directed  towards  the  rete  testis  (2); 
and  when  they  have  reached  to 
within  a  line  or  two  of  this,  they 
cease  to  be  convoluted,  several  unite 
together  into  tubes  of  larger  diame- 
ter. and  these  enter  the  rete  testis 

Human  Test  ?«,  injected  with  mercury  as  completely         \       ,,  £  .   7    7.        ,.    mr 

as  possible:-!,  1,  lobulus  formed  of  seminiferous  under  the  name  of  tubuli  rectt.  The 
tubes;  2,  rete  testis;  3,  vasa  efferentia;  4,  flexures  mode  in  which  the  tubuli  terminate 
of  the  efferent  vessels  passing  in  to  the  head  5,  5,  of  the  at  the  large  end  of  the  lobule,  has 
epididymis  ;  6,  body  of  the  epididymis  ;  7,  appendix  ;  not  been  clearly  made-out,  owing 
8,  cauda;  9,  vas  deferens. 


tomoses  ;  it  is  probably  either  by  csecal  endings,  or  by  loops.  The  diameter  of  the 
tubuli  is  for  the  most  part  very  uniform  ;  in  the  natural  condition  they  seem  to  vary 
from  about  the  l-190th  to  the  l-170th  of  an  inch;  but  when  injected  with  mer- 
cury, they  are  distended  to  a  size  nearly  double  the  smaller  of  these  dimensions.  — 
The  rete  testis  (2)  consists  of  from  seven  to  thirteen  vessels,  which  run  in  a  waving 
course,  anastomose  with  each  other,  and  again  divide,  being  all  connected  to- 
gether. The  vasa  efferentia  (3),  which  pass  to  the  head  of  the  epididymis,  are 
at  first  straight,  but  soon  become  convoluted  (4),  each  forming  a  sort  of  cone,  of 
which  the  apex  is  directed  towards  the  rete  testis,  the  base  to  the  head  of  the 
epididymis  (5).  The  number  of  these  is  stated  to  vary  from  nine  to  thirty  ;  and 
their  length  to  be  about  eight  inches.  The  epididymis  itself  (6)  consists  of  a 
very  convoluted  canal,  the  length  of  which  is  about  twenty-one  feet.  Into  its 
lower  extremity,  that  is,  the  angle  which  it  makes  where  it  terminates  in  the  vas 
deferens,  is  poured  the  secretion  of  the  vasculum  alerrans  or  appendix  (7); 


OF    THE    TESTES    AND    SEMINAL    FLUID. 


749 


FIG.  199. 


which  seems  like  a  testis  in  miniature,  closely  resembling  a  single  lobule  in  its 
structure.     Its  special  function  is  unknown. 

842.  The  fluid  secreted  by  the  Testis  is  mingled,  during  or  previously-to  ita 
emission,  with  fluid  secreted  by 
the  Vesiculas  Seminales,  the  Pros- 
tate, Cowper's  glands,  &c. ;  and 
it  cannot,  therefore,  be  obtained 
pure,  but  by  drawing  it  from  the 
testicle  itself.  No  accurate  analy- 
sis has  been  made  of  it  in  the 
Human  subject;  but  the  following 
are  the  results  of  those  which 
have  been  made  by  Frerichs1  on 
the  contents  of  the  testes  of  a 
rabbit,  a  cock,  and  a  carp.  Pure 
Semen  is  a  milky  fluid,  of  a  mu- 
cous consistence,  and  neutral  or 
slightly-alkaline  reaction.  The 
imperfectly-developed  Spermato- 
zoa are  composed  of  an  albuminous 
substance,  the  quantity  of  which 
diminishes  with  their  progress  to- 
wards maturation;  so  that  the 
perfectly-developed  semen  con- 
tains no  albuminous  compound. 
On  the  other  hand,  the  principal  plan  of  the  ^^  of  fte  ^ ,,  &nd 
component  substance  of  the  ma-  a>  a>  seminiferous  tubes ;  a*,  a*,  their  anastomoses;  the 
ture  Spermatozoa  is  the  same  with  other  references  as  in  the  last  figure, 
that  which  is  the  chief  constituent 

of  the  Epithelia  and  of  the  Horny  tissues  generally,  namely,  the  '  binoxide  of  pro- 
tein' of  Mulder.  Besides  this,  the  spermatozoa  contain  about  4  per  cent,  of  a 
butter-like  fat,  with  some  phosphorus  in  an  unoxidized  state,  (probably  combined 
with  the  fat,  as  in  the  phosphorized  fats  of  the  blood-corpuscles  and  of  nervous 
matter),  and  about  5  per  cent,  of  phosphate  of  lime.  The  fluid  portion  of  the  secre- 
tion is  a  thin  solution  of  mucus,  which,  in  addition  to  the  animal  matter,  contains 
chloride  of  sodium,  and  small  quantities  of  alkaline  sulphates  and  phosphates.  The 
peculiar  odour  which  the  Semen  possesses,  does  not  appear  to  belong  to  the  pro- 
per spermatic  fluid;  but  is  probably  derived  from  one  or  other  of  the  secretions 
with  which  it  is  mingled. — The  product  of  the  secretion  of  each  Testis  is 
conveyed-away  by  a  single  vas  deferens  (i),  which  is  a  cylindrical  canal,  having 
within  its  fibrous  wall,  a  layer  of  non-striated  muscular  fibre,  and  being  lined  by 
a  proper  mucous  membrane.  The  va»s  deferens  ascending  into  the  abdominal 
cavity  as  a  part  of  the  spermatic  cord,  reaches  the  fundus  of  the  bladder;  and 
there  it  comes  into  proximity  with  the  Vesicula  S^minalis  of  its  own  side,  with 
whose  duct  it  unites,  to  form  the  ejaculatory  duct  which  terminates  on  the  veru- 
montanum  of  the  urethra.  It  has  been  commonly  supposed  that  the  vesiculse 
seminales  stand  to  the  vasa  defererttia  in  the  same  light  that  the  gall-bladder 
stands  to  the  hepatic  duct ;  namely,  as  a  receptacle  into  which  the  seminal  fluid 
may  regurgitate,  and  within  which  it  may  accumulate ;  but  (as  Hunter  was  the 
first  to  maintain)  this  is  not  the  case,  since  the  fluid  that  is  found  in  them  is  not 
semen,  and  but  rarely  contains  even  a  small  admixture  of  seminal  fluid.2  More- 
over, these  organs  are  not  simple  vesicles,  but  have  a  sacculated  glandular  cha- 
racter ;  and  their  secretion  seems  to  be  of  a  mucous  nature.  Into  the  same  part 
of  the  urethra  is  discharged  the  secretion  of  the  Prostate  Gland,  which  is  poured- 

1  Art.  « Semen '  in  "  Cyclop,  of  Anat.  and  Physiol.,"  vol.  iv.  p.  506. 

2  See  Art.  'Veticuke  Seminal**,'  in  "Cyclop,  of  Anat.  and  Physiol.,"  vol.  iv.  p.  1431. 


750        OF  GENERATION:  —  ACTION  OF  THE  MALE. 

forth  by  a  number  (15 — 20)  of  separate  ducts  into  a  depressed  fossa  on  either 
side  j  of  the  nature  of  this  secretion  scarcely  anything  is  known ;  and  it  can  be 
only  surmised  that  its  use,  like  that  of  the  fluid  of  the  vesiculae  seminales,  is  to 
dilute  the  seminal  fluid,  and  to  give  it  such  an  increase  of  bulk  that  it  may  be 
more  effectually  conveyed  within  the  female  passages.  It  seems  probable,  in- 
deed, that  a  certain  dilution  of  the  fluid  secreted  by  the  testes  may  be  a  condition 
of  its  power  of  fecundation ;  since  it  has  been  ascertained  by  Mr.  Newport,  that 
too  copious  an  application  of  spermatozoa  to  an  ovum  is  absolutely  unfavourable 
to  their  action. — That  in  some  way  or  other  both  these  glandular  bodies  serve  as 
accessory  organs  of  generation,  may  be  inferred  from  the  fact,  that  in  animals 
which  have  only  a  periodical  aptitude  for  procreation,  they  undergo  an  alternate 
increase  and  decrease,  corresponding  with  the  periodical  enlargement  and  diminu- 
tion of  the  testes  themselves. 

843.  The  essential  peculiarity  of  the  Spermatic  fluid,  however,  consists  in  the 
presence  of  a  large  number  of  very  minute  bodies,  the  spermatozoa,  which,  from 
their  usually  remaining  in  active  motion  for  some  time  after  they  have  quitted 
the  living  organism,  have  been  erroneously  considered  as  proper  Animalcules. 
The  Human  Spermatozoon  (of  which  representations  are  given  in  Plate  I.,  Fig.  1) 
consists  of  a  little  oval  flattened  'body'  between  the  l-600th  and  the  l-800th 
of  a  line  in  length,  from  which  proceeds  a  long  filiform  '  tail '  gradually  tapering 
to  the  finest  point,  of  l-50th  or  at  most  l-40th  of  a  line  in  length.  The  whole 
is  perfectly  transparent;  and  nothing  that  can  be  termed  ' structure'  can  be 
satisfactorily  distinguished  within  it.  Its  movements  are  principally  executed 
by  the  tail,  which  has  a  kind  of  vibratile  undulating  motion ;  they  may  continue 
for  many  hours  after  the  emission  of  the  fluid ;  and  they  are  not  checked  by  its 
admixture  with  other  secretions,  such  as  the  urine  and  the  prostatic  fluid.  Thus, 
in  cases  of  nocturnal  emission,  the  Spermatozoa  may  not  unfrequently  be  found 
actively  moving  through  the  urine  in  the  morning ;  and  those  contained  in  the 
seminal  fluid  collected  from  females  that  have  just  copulated,  are  frequently 
found  to  live  many  days.  Their  presence  may  be  readily  detected  by  an  observer 
familiar  with  their  appearance,  and  furnished  with  a  Microscope  of  sufficient 
power,  even  when  they  have  long  ceased  to  move,  and  are  broken  into  fragments } 
and  the  Physician  and  the  Medical  Jurist  will  frequently  derive  much  assistance 
from  an  examination  of  this  kind.  Thus,  cases  are  of  no  uncommon  occurrence, 
especially  among  those  who  have  been  too  much  addicted  to  sexual  indulgence, 
in  which  seminal  emissions  take-place  unconsciously  and  frequently,  and  produce 
great  general  derangement  of  the  health ;  and  the  true  nature  of  the  complaint 
is  obscure,  until  the  fact  has  been  detected  by  ocular  examination.  Again,  in 
charges  of  rape,  in  which  evidence  of  actual  emission  is  required,  a  microscopic 
examination  of  the  stiffened  spots  left  on  the  linen  will  seldom  fail  in  obtaining 
proof,  if  the  act  have  been  completed  :  in  such  cases,  however,  we  must  not  ex- 
pect to  meet  with  more  than  fragments  of  Spermatozoa ;  but  these  are  so  unlike 
anything  else,  that  little  doubt  need  be  entertained  regarding  them.  It  has  been 
proposed  to  employ  the  same  test,  in  juridical  inquiries  respecting  doubtful  cases 
of  death  by  suspension,  seminal  emissions  being  not  unfrequent  results  of  this 
kind  of  violence ;  but  there  are  many  obvious  objections  which  should  prevent 
much  confidence  being  placed  in  it.1 

844.  The  mode  of  evolution  of  the  Spermatozoa,  first  discovered  by  Wagner, 
and  more  perfectly  elucidated  by  Kolliker,  is  such  as  to  indicate  that  these  bodies 
are  true  products  of  the  formative  action  of  the  organs  in  which  they  are  found, 
and  cannot  be  ranked  in  the  same  category  with  Animalcules.  They  are  deve- 
loped in  the  interior  of  cells,  or  f  vesicles  of  evolution,'  such  a£  are  visible  in  the 
seminal  fluid  in  various  stages  of  production  (Plate  L,  Fig.  2,  A,  B,  c),  and  have 
been  known  under  the  name  of  f  seminal  granules.'  These  appear  to  have  been 

1  See  the  Author's  Article  'Asphyxia,'  In  the  "Library  of  Practical  Medicine,"  and 
\he  authorities  there  referred  to. 


SEMINAL  FLUID:  —  SPERMATOZOA.  751 

themselves  formed  within  parent-cells,  which  are  probably  to  be  regarded  as  the 
epithelial  cells  of  the  tubuli  seminiferi ;  constituting,  like  the  analogous  cells  of 
other  glands,  the  essential  elements  of  the  spermatic  apparatus.  These  parent- 
cells  are  sometimes  observed  to  contain  but  a  single  '  vesicle  of  evolution/  as 
shown  at  D ;  but  more  commonly  from  three  to  seven  are  to  be  seen  within  them 
(E).  When  taken  from  a  body  recently  dead,  and  examined  without  being 
treated  with  water  or  any  other  agent,  they  are  quite  pellucid,  and  exhibit  a  deli- 
cate contour  with  perfectly  homogeneous  contents;  very  speedily,  however,  a  sort 
of  coagulation  takes-place  within  them,  by  which  their  contents  are  rendered 
granular.  Each  of  these  '  vesicles  of  evolution '  gives  origin  to  a  spermatozoon, 
and  to  one  only;  the  earliest  stages  of  its  development  have  not  yet  been  fully 
made-out,  since  it  does  not  at  first  exhibit  those  sharp  distinct  contours,  depen- 
dent on  its  great  refractive  power,  which  afterwards  distinguish  it;  but  it  is  seen 
lying  in  the  interior  of  the  cell  as  a  slight  linear  shadow,  at  first  partly  hidden  bj 
the  surrounding  granules  (Fig.  3,  B),  but  afterwards  without  any  such  obscura- 
tion. When  the  vesicle  is  completely  matured,  it  bursts,  and  gives  exit  to  the 
contained  spermatozoon ;  but  it  is  common  for  the  parent-cells  to  retain  the  vesi- 
cles of  evolution,  during  the  development  of  the  spermatozoa  within  the  latter; 
so  tha-t  the  spermatozoa  set-free  by  the  rupture  of  these,  are  still  enveloped  by  the 
parent-ce-11.  In  this  condition  they  have  a  tendency  to  aggregation  in  bundles; 
and  these  bundles  are  finally  liberated  by  the  rupture  of  the  parent-cell,  after 
which  the  individual  spermatozoa  separate  one  from  another.  The  spermatozoa 
are  not  normally  found  free  in  the  tubuli  seminiferi;  although  they  may  be  there 
so  far  advanced  in  development,  that  the  addition  of  water  liberates  them  by 
occasioning  the  rupture  of  their  envelopes.  In  the  rete  testis  and  vasa  eiferentia, 
the  spermatozoa  are  very  commonly  found  lying  in  bundles  within  the  parent- 
cells,  the  vesicles  of  evolution  having  disappeared ;  and  they  are  usually  set-free 
completely  by  the  time  that  they  reach  the  epididymis,  though  still  frequently 
associated  in  bundles.  The  earlier  phases  are  occasionally  met-with,  however, 
even  in  the  vas  deferens.1 

845.  That  the  Spermatozoa  are  the  essential  elements  of  the  spermatic  fluid, 
may  be  reasonably  inferred  from  several  considerations.    Thei'e  are  some  cases  in 
which  the  l  liquor  seminis '  is  altogether  absent,  so  that  they  constitute  the  sole 
element  of  the  semen ;  whilst,  on  the  other  hand,  they  are  never  wanting  in  the 
semen  of  animals  capable  of  procreation ;  but  are  absent,  or  imperfectly  deve- 
loped, in  the  semen  of  hybrids,  which  are  nearly  or  entirely  sterile.     Moreover, 
it  may  be  considered  as  certain  that  the  absolute  contact  of  the  spermatozoa  with 
the  ovum  (§  860)  is  requisite  for  its  fecundation ;  whilst,  on  the  other  hand,  if 
the  spermatozoa  be  carefully  removed  from  the  liquor  seminis  by  filtration,  the 
latter  is  entirely  destitute  of  fertilizing  power.2     Hence  the  presence  of  the 
Liquor  Seminis  must  be  considered  as   merely  incidental ;  and  as  answering 
some  secondary  purpose,  either  in  the  development  or  in  the  conveyance  of  the 
Spermatozoa. 

846.  The  power  of  procreation  does  not  usually  exist  in  the  Human  Male, 
before  the  age  of  from  14  to  16  years ;  and  it  may  be  considered  probable  that  no 
Spermatozoa  are  produced  until  that  period,  although  a  fluid  is  secreted  by  the 
testes.     At  this  epoch,  which  is  ordinarily  designated  as  that  of  Puberty,  a  con- 
siderable change  takes-place  in  the  bodily  constitution  :  the  sexual  organs  undergo 
a  much  increased  development ;  various  parts  of  the  surface,  especially  the  chin 
and  the  pubes,  become  covered  with  hair;  the  larynx  enlarges,  and  the  voice 
becomes  lower  in  pitch,  as  well  as  rougher  and  more  powerful ;  and  new  feelings 

1  For  the  latest  researches  on  the  development,  &c.,  of  the  Spermatozoa,  see  the  elaborate 
Article  'Semen,'  in  the  'Cyclop,  of  Anat.  and  Physiol.,"  by  Drs.  Wagner  and  Leuckardt, 
and  Prof.  Kolliker's  "  Mikroskopische  Anatomic,"  band,  ii.,  §  226. 

a  This  point  has  been  completely  established  by  the  researches  of  Mr.  Newport  ("Phil. 
Trans.,"  1851),  who  has  repeated  and  confirmed  the  experimental  results  previously  ob- 
tained by  Spallanzani  and  by  Prevost  and  Dumas. 


752       OF   GENERATION:  — ACTION  OF  THE  MALE. 

and  desires  are  awakened  in  the  Jaind.  Instances,  however,  are  by  no  means 
rare,  in  which  these  changes  occur  at  a  much  earlier  period  ;  the  full  develop- 
ment of  the  generative  organs,  with  manifestations  of  the  sexual  passion,  having 
been  observed  in  children  but  a  few  years  old.  The  procreative  power  may  last, 
if  not  abused,  during  a  very  prolonged  period.  Undoubted  instances  of  virility  at 
the  age  of  more  than  100  years  are  on  record ;  but  in  these  cases,  the  general 
bodily  vigour  was  preserved  in  a  very  remarkable  degree.  The  ordinary  rule 
seems  to  be,  that  sexual  power  is  not  retained  by  the  male  to  any  considerable 
amount,  after  the  age  of  60  or  65  years. 

847.  To  the  use  of  the  sexual  organs  for  the  continuance  of  his  race,  Man  i8 
prompted  by  a  powerful  instinctive-desire  (§  561),  which  he  shares  with  the  lower 
animals.  This  Instinct,  like  the  other  propensities,  rs  excited  by  sensations; 
and  these  may  either  originate  in  the  sexual  organs  themselves,  or  may  be  excited 
through  the  organs  of  special  sense.  Thus  in  Man  it  is  most  powerfully  aroused 
by  impressions  conveyed  through  the  sight  or  the  touch  ;  but  in  many  other  ani- 
mals, the  auditory  and  olfactory  organs  communicate  impressions  which  have  an 
equal  power ;  and  it  is  not  improbable  that,  in  certain  morbidly-excited  states  of 
feeling,  the  same  may  be  the  case  in  ourselves.  Localized  sensations  have  also  a 
very  powerful  effect  in  exciting  sexual  desire,  as  must  have  been  within  the  expe- 
rience of  almost  every  one ;  the  fact  is  most  remarkable,  however,  in  cases  of 
Satyriasis,  which  disease  is  generally  found  to  be  connected  with  some  obvious 
cause  of  irritation  of  the  generative  system,  such  as  pruritus,  active  congestion, 
&c.  That  some  part  of  the  Encephalon  is  the  seat  of  this  as  of  other  instinctive 
propensities,  appears  from  the  considerations  formerly  adduced;  but  that  the 
Cerebellum  is  the  part  in  which  this  function  is  specially  located,  cannot  be  re- 
garded as  by  any  means  sufficiently  proved  (§§  557-561).  The  instinct,  when 
once  aroused  (even  though  very  obscurely  felt),  acts  upon  the  mental  faculties 
and  moral  feelings ;  and  thus  becomes  the  source,  though  almost  unconsciously 
so  to  the  individual,  of  the  tendency  to  form  that  kind  of  attachment  towards  one 
one  of  the  opposite  sex,  which  is  known  as  love.  This  tendency  cannot  be  re- 
garded as  a  simple  passion  or  emotion,  since  it  is  the  result  of  the  combined  ope- 
rations of  the  reason,  the  imagination,  and  the  moral  feelings ;  and  it  is  in  this 
engraftment  (so  to  speak)  of  the  psychical  attachment,  upon  the  mere  corporeal 
instinct,  that  a  difference  exists  between  the  sexual  relations  of  Man  and  those 
of  the  lower  animals.  In  proportion  as  the  Human  being  makes  the  temporary 
gratification  of  the  mere  sexual  appetite  his  chief  object,  and  overlooks  the  happi- 
ness arising  from  spiritual  communion,  which  is  not  only  purer  but  more  perma- 
nent, and  of  which  a  renewal  may  be  anticipated  in  another  world, — does  he  de- 
grade himself  to  a  level  with  the  brutes  that  perish.  Yet  how  lamentably  fre- 
quent is  this  degradation ! 

848.  When,  impelled  by  sexual  excitement,  the  Male  seeks  intercourse  with, 
the  Female,  the  erectile  tissue  of  the  genital  organs  becomes  turgid  with  blood 
(§  282),  and  the  surface  acquires  a  much-increased  sensibility;  this  is  especially 
acute  in  the  Glans  penis.  By  the  friction  of  the  Glans  against  the  rugous  walls 
of  the  Vagina,  the  excitement  is  increased ;  and  the  impression  which  is  thus 
produced  at  last  becomes  so  strong,  that  it  calls-forth,  through  the  medium  of  the 
Spinal  Cord,  a  reflex  contraction  of  the  muscular  fibres  of  the  Vasa  Deferentia, 
and  of  the  muscles  which  surround  the  Vesiculse  Seminalee,  and  Prostate  Gland. 
These  receptacles  discharge  their  contents  into  the  Urethra ;  from  which  they 
are  expelled  with  some  degree  of  force,  and  with  a  kind  of  convulsive  action, 
by  its  own  Compressor  muscles.  Now  although  the  sensations  concerned  in  this 
act  are  ordinarily  most  acutely  pleasurable,  there  appears  sufficient  evidence  that 
they  are  by  no  means  essential  to  its  performance;  and  that  the  impression  which 
is  conveyed  to  the  Spinal  Cord  need  not  give  rise  to  a  sensation,  in  order  to  pro- 
duce the  reflex  contraction  of  the  Ejaculator  muscles  (§  511).  The  high  degree 
of  nervous  excitement  which  the  act  of  coition  involves,  produces  a  subsequent 


OF  THE  OVUM  AND  ITS  DEVELOPMENT. 


753 


depression  to  a  corresponding  amount;  and  the  too  frequent  repetition  of  it  is 
productive  of  consequences  very  injurious  to  the  general  health.  This  is  still 
more  the  case  with  the  solitary  indulgence,  which  (it  is  to  be  feared)  is  practised 
by  too  many  youths;  for  this  substituting  an  unnatural  degree  of  one  kind  of 
excitement,  for  that  which  is  wanting  in  another,  cannot  but  be  still  more  trying 
to  the  bodily  powers.  The  secretion  of  seminal  fluid  being,  like  other  secretions, 
very  much  under  the  control  of  the  nervous  system,  will  be  increased  by  the  con- 
tinual direction  of  the  mind  towards  objects  which  awaken  the  sexual  propensity 
(§  832);  and  thus,  if  a  frequent  discharge  be  occasioned,  whether  by  natural  or 
unnatural  excitement,  a  much  larger  quantity  will  altogether  be  produced,  although 
the  amount  emitted  at  each  period  will  be  less,  and  its  due  perfection  will  not  be 
attained,  the  fluid  under  such  circumstances  being  found  to  contain  an  unduly- 
large  proportion  of  immature  seminal  cells.  The  formation  of  the  secretion  seems 
of  itself  to  be  a  much  greater  tax  upon  the  corporeal  powers,  than  might  have 
been  supposed  d  priori :  and  it  is  a  well-known  fact,  that  the  highest  degree  of 
bodily  vigour  is  inconsistent  with  more  than  a  very  moderate  indulgence  in 
sexual  intercourse ;  whilst  nothing  is  more  certain  to  reduce  the  powers,  both  of 
body  and  mind,  than  excess  in  this  respect. — These  principles,  which  are  of  great 
importance  in  the  regulation  of  the  health,  are  but  expressions  of  the  general  law 
(which  prevails  equally  in  the  Vegetable  and  in  the  Animal  kingdom),  that  the 
Development  of  the  Individual,  and  the  Reproduction  of  the  Species,  stand  in  an 
inverse  ratio  to  each  other. 


3. — Action  of  the  Female. 

849.  The  essential  part  of  the  Female  Generative  system,  is  that  in  whick  the 
Ova  are  prepared;  the  other  organs  are  merely  accessory,  and  are  not  to  be  found 
in  a  large  proportion  of  the  Animal  kingdom.  In  many  of  the  lower  animals, 
the  Ovarium  consists  of  a  loose  tissue  containing  many  areolse,  in  which  the  Ova 
are  formed,  and  from  which  they  escape  by  the  rupture  of  the  cell-walls;  in  the 
higher  animals,  as  in  the  Human  female,  the  substance  of  the  Ovarium  is  firm 
and  compact,  and  consists  of  a  nucleated,  tough,  fibrous,  though  not  distinctly 
fibrillar,  connective  tissue,  forming  what  is  known  as  the  stroma;  and  the  Ova, 

[Pxo.  200. 


Diagram  of  a  Graafian  vesicle,  containing  an  ovum :  1.  Stroma  or  tissue  of  the  ovary.  2  and 
8.  External  and  internal  tunics  of  the  Graafian  vesicle.  4.  Cavity  of  the  vesicle.  5.  Thick 
tunic  of  the  ovum,  or  yelk-sac.  6.  The  yelk.  7.  The  germinal  vesicle.  8.  The  germinal  spot.] 

except  when  they  are  approaching  maturity ;  can  only  be  distinguished  in  the 
interstices  of  this,  by  the  aid  of  a  high  magnifying  power.  The  Ovum  in  all  Ver- 
tcbrated  animals  is  produced  within  a  capsule  or  bag,  the  exterior  of  which  is  in 
contact  with  the  stmma  of  the  ovarium  ;  this  has  been  termed,  in  Mammalia,  the 
Graafan  vesicle,  after  the  name  of  its  first  discoverer ;  but  the  more  general  and 
48 


754         OF    GENERATION: — ACTION    OF    THE    FEMALE. 

appropriate  designation  of  Ovisac  was  given  to  it  by  Dr.  Barry,  who  showed  that 
it  exists  in  other  classes  of  Vertebrata. '  Between  the  Ovum  and  the  Ovisac,  in 
Oviparous  animals,  there  is  scarcely  any  interval ;  but  in  the  Mammalia,  a  large 
amount  of  granular  matter  (composed  of  nucleated  cells,  loosely-aggregated 

FIG.  201. 


Constituent  parts  of  Mammalian  Ovum : — A,  entire ;  B,  ruptured,  with  the  contents   escap- 
ing;— m  v,  vitelline  membrane;  j.  yolk  ;  v  g,  germinal  vesicle;  t  g,  germinal  spot. 

together)  is  present ;  being  especially  found  adherent  to  the  lining  of  the  ovisac, 
to  which  it  forms  a  sort  of  epithelium,  or  internal  tunic,  known  as  the  membrana 
granulosa ;  whilst  it  also  forms  a  disk-like  investment  to  the  ovum,  which  is 
termed  the  discus  proligerus.  The  membrane  which  incloses  the  yolk  in  Mam- 
malia, has  received,  on  account  of  its  thickness  and  peculiar  transparency,  the 
distinctive  appellation  of  zona  pellucida,  (Fig.  201,  m  v). — The  yolk  or  vitellus 
(j),  which  is  composed  of  albumen  and  oil-particles,  with  traces  of  cells,  is  very 
small  in  the  Mammalian  ovum,  its  function  being  limited  to  the  sustenance  of 
the  germ  during  its  earliest  period  of  development ;  and  it  corresponds  rather  with 
that  part  of  the  yolk  of  the  egg  of  the  higher  Ovipara  which  has  been  distin- 
guished as  the  'germ-yolk/  in  consequence  of  its  direct  participation  in  the  for- 
mation of  the  germinal  substance  (§  887),  than  with  that  which  has  been  termed 
the  '  food-yolk/  as  not  being  incorporated  with  the  germ,  but  being  destined  for  its 
subsequent  nutrition  by  undergoing  conversion  into  blood.2  Occupying  the  centre 
of  the  vitelline  mass,  in  the  immature  ovum,  is  a  peculiar  cell,  very  different  in 
its  aspect  from  the  surrounding  substance,  which  is  termed  the  germinal  vesicle 
(Fig.  201,  vg)  ;  and  this  has  a  very  distinct  nucleus  (tg)  known  as  the  germinal 
spot.  This  cell  must  be  considered  as  the  essential  part  of  the  ovum,  and  as 
homologous  with  the  'germ-cell'  or  ' embryonic  vesicle'  of  the  Vegetable  ovule. 
— The  Human  Ovum  is  extremely  minute ;  not  measuring  above  l-120th  of  an 
inch  in  diameter,  and  being  sometimes  no  more  than  half  that  size.  The  diam- 
eter of  the  germinal  vesicle  of  the  Human  ovum  has  not  yet  been  ascertained, 
owing  to  the  difficulty  of  isolating  it  from  the  yolk ;  in  the  ovum  of  the  Rabbit, 
it  is  about  l-720th  of  an  inch ;  and  that  of  the  germinal  spot,  in  the  Mammalia 
generally,  is  from  l-3600th  to  l-2400th  of  an  inch. 

850.  It  appears,  from  the  researches  of  Valentin  and  Bishoff,  that  the  Graafian 
vesicle,  or  Ovisac,  is  formed  previously  to  the  Ovum,  which  is  subsequently  de- 
veloped in  its  interior ;  and  it  would  seem  that  we  may  regard  it  as  a  vesicle  of 
evolution  for  the  ovum,  in  the  same  way  that  the  gland-cells  of  the  testes  act  as 
vesicles  of  evolution  for  the  spermatozoa.  The  development  of  ovisacs  commences 

1  "Researches  in  Embryology,"  1st  series,  in  "  Philos.  Transact,"  1838. 

a  It  has  been  recently  maintained  by  Reinhardt,  that  the  Bird's  yolk-bag  is  really  homo- 
logous with  the  Graafian  vesicle  of  the  Mammal  and  its  entire  contents;  the  'food-yolk' 
of  the  former  being  represented  in  the  latter  by  the  cellular  substance  surrounding  the 
gona  pellucida,  which  is  afterwards  developed  into  the  Corpus  Luteum.  ("Kolliker  and 
Siebold's  Zeitschrift,"  band.  iii.  heft.  4.) 


OF    THE    OVUM    AND    ITS    DEVELOPMENT. 


755 


FlG-  202- 


at  a  very  early  period  of  life  ;  in  the  ovaries  of  some  animals,  they  can  be  de- 
tected almost  as  soon  as  these  organs  are  themselves  evolved  ;  and  in  all,  they 
show  themselves  soon  after  birth.  In  Plate  L,  Fig.  4,  is  represented  the  condi- 
tion of  the  Graafian  vesicles  in  various  stages  of  development,  as  they  are  seen 
imbedded  in  the  fibrous  stroma  of  the  ovarium,  in  a  thin  slice  from  the  ovary  of 
a  sow  three  weeks  old  ;  by  which  time  the  germinal  vesicle,  which  is  the  first 
part  of  the  ovum  that  makes  its  appearance,  has  been  developed  in  their  interior. 
The  germinal  vesicle,  which  distinctly  shows  the  germinal  spot,  is  surrounded  by| 
an  assemblage  of  granules,  which  gives  the  first  indication  of  a  yolk  ;  and  around 
these,  the  zona  pellucida  appears  to  be  subsequently  developed.  The  ovum  at 
first  occupies  the  centre  of  the  Graafian  vesicle,  but  it  subsequently  removes  to 
its  periphery  ;  and,  when  the  contents  of  the  ovisac  are  undergoing  maturation, 
prior  to  their  escape,  the  ovum  is  always  found  on  the  side  of  it  nearest  to  the 
surface  of  the  ovary.  The  proper  Ovisac,  whose  wall  is  formed  of  a  non-vascular 
membrane,  is  surrounded  by  a  vascular  layer,  which  is  formed  by  a  condensation 
of  the  ordinary  stroma  of  the  ovarium  ;  it  is  this  which  is  usually  described  as 
the  outer  layer  of  the  Graafian  vesicle. 

851.  A  continual  change  seems  to  be  taking-place  in  the  contents  of  the  Ova- 
rium, during  the  greater  part  of  life;  certain  of  the  Ovi- 
sacs  or  Graafian  vesicles,  and  their  contents,  successively 
arriving  at  maturity,  whilst  others  degenerate  and  die. 
According  to  the  valuable  inquiries  of  Dr.  Ritchie,1  it  ap- 
pears that  even  during  the  period  of  childhood,  there  is  a 
continual  rupture  of  ovisacs  and  discharge  of  ova,  at  the 
surface  of  the  ovarium.  The  Ovaria  are  studded  with  nu- 
merous minute  copper-coloured  maculae,  and  their  surface 
presents  delicate  vesicular  elevations,  which  are  occasioned 
by  the  most  matured  ovisacs  ;  the  dehiscence  of  these  takes- 
place  by  minute  punctiform  openings  in  the  peritoneal  coat, 
and  no  cicatrix  is  left.  At  the  period  of  puberty,  the 
stroma  of  the  ovarium  is  crowded  with  ovisacs  ;  which  are 
still  so  minute,  that  in  the  Ox  (according  to  Dr.  Barry's 
computation)  a  cubic  inch  would  contain  200  millions  of 
them.  The  greatest  advance  is  seen  in  those  which  are 
situated  near  the  surface  of  the  Ovarium  ;  and  in  such,  the 
Graafian  vesicle,  with  its  two  coats,  may  be  distinctly  traced. 
In  those  animals  whose  aptitude  for  conception  is  periodical, 
the  development  of  the  ova  to  such  a  degree  that  they  be- 
come prepared  for  fecundation,  is  periodical  also.  This 
development  is  made  evident,  when  the  parts  are  examined 
in  an  animal  which  is  'in  heat/  by  the  projection  of  the  bit>  at  the  Period  of 
Graafian  vesicles  from  the  surface  (Fig.  202);  and  it  con-  ££  JS*jgS 
sists  not  merely  in  an  increase  of  size,  but  in  certain  in-  Of  ova. 
ternal  changes  presently  to  be  described  (§  856). 

852.  In  the  Human  female,  the  period  of  Puberty,  or  commencing  aptitude 
for  procreation,  is  usually  between  the  13th  and  16th  years;  it  is  generally 
thought  to  be  somewhat  earlier  in  warm  climates  than  in  cold,2  and  in  densely- 
1  "  London  Medical  Gazette,"  1844. 

9  It  has  been  stated,  by  almost  all  Physiological  writers,  that  women  (like  fruits)  reach 
maturity,  and  that  menstruation  commences,  much  earlier  in  hot  climates,  particularly 
between  the  tropics,  than  in  temperate  and  very  cold  countries.  From  many  elaborate 
and  interesting  papers  which  have  been  published  within  a  few  years,  however,  especially 
from  those  of  Mr.  Roberton  of  Manchester  (recently  collected  in  his  "  Essays  on  Men- 
struation, and  on  Practical  Midwifery,"  1851),  it  would  seem  that  the  natural  period  of 
puberty  in  temperate  climates  occurs  in  a  much  more  extended  range  of  ages,  and  is 
much  more  equally  distributed  through  that  range,  than  others  have  alleged  ;  and  that, 
in  other  countries,  the  supposed  parallel  between  plants  and  fruits  does  not  hold  good. 


Ovarium  of  the 


756       OF    GENERATION:  —  ACTION    OF    THE    FEMALE. 

populated  manufacturing  towns  than  in  thinly-peopled  agricultural  districts.  The 
mental  and  bodily  habits  of  the  individual  have  also  considerable  influence  upon 
the  time  of  its  occurrence ;  girls  brought-up  in  the  midst  of  luxury  or  sensual 
indulgence,  undergoing  this  change  earlier  than  those  reared  in  hardihood  and 
self-denial.  The  changes  in  which  puberty  consists,  are  for  the  most  part  con- 
nected with  the  Reproductive  system.  The  external  and  internal  organs  of 
generation  undergo  a  considerable  increase  of  size  ;  the  mammary  glands  enlarge ; 
and  a  deposition  of  fat  takes-place  in  the  mammae  and  on  the  pubes,  as  well  as 
over  the  whole  surface  of  the  body,  giving  to  the  person  that  roundness  and  ful-  - 
ness,  which  are  so  attractive  to  the  opposite  sex  at  the  period  of  commencing 
womanhood.  The  first  appearance  of  the  Catainenia  usually  occurs  whilst  these 
changes  are  in  progress,  and  is  a  decided  indication  of  the  arrival  of  the  period 
of  puberty  ;  but  it  is  not  unfrequently  delayed  much  longer;  and  its  absence  is 
by  no  means  to  be  regarded  as  a  proof  of  the  want  of  aptitude  for  procreation, 
since  many  women  have  borne  large  families  without  having  ever  menstruated. 
The  Oatamenial  discharge,  as  it  issues  from  the  uterus,  appears  to  be  nearly  or 
quite  identical  with  ordinary  blood ;  but  in  its  passage  through  the  vagina,  it 
becomes  mixed  with  the  acid  mucus  exuded  from  its  walls,  which  usually  deprives 
it  of  the  power  of  coagulating.  If  the  discharge  should  be  profuse,  however,  a 
portion  of  its  fibrin  remains  unaffected,  and  clots  are  formed.  In  cases  in  which, 
by  the  death  of  women  at  this  period,  an  opportunity  has  been  afforded  for  the 
examination  of  the  lining  membrane  of  the  uterus  during  menstruation,  it  is 
found  to  be  unusually  turgid  with  blood,  the  veins  in  particular  being  much  dis- 
tended, and  opening  upon  the  internal  surface  by  capillary  orifices,  to  which  val- 
vules  are  occasionally  found  attached.1  Hence  it  is  scarcely  correct  to  designate 
the  menstrual  flux  as  a  '  secretion ;'  although  there  is  reason  to  think  that  it 
may  carry-off,  besides  blood,  certain  matters  which  would  be  appropriate  to  the 
formation  of  a  Pecidual  membrane  (§  863),  but  which,  if  not  so  employed,  be- 
come excrementitious. — The  interval  which  usually  elapses  between  the  successive 
appearances  of  the  discharge,  is  about  four  weeks ;  and  the  duration  of  the  flow 
is  from  three  to  six  days.  There  is  great  variety  in  this  respect,  however,  among 
the  inhabitants  of  different  climates,  and  among  individuals;  in  general,  the 
appearance  is  more  frequent,  and  the  duration  of  the  flow  greater,  among  the 
residents  in  warm  countries,  and  among  individuals  of  luxurious  habits  and  re- 
laxed frame,  than  among  the  inhabitants  of  colder  climes,  or  among  individuals 
inured  to  bodily  exertion.  The  first  appearance  of  the  discharge  is  usually  pre- 
ceded and  accompanied  by  considerable  general  disturbance  of  the  system,  espe- 
cially pain  in  the  loins  and  a  sense  of  fatigue  in  the  lower  extremities ;  and  its 
periodical  return  is  usually  attended  with  the  like  symptoms,  which  are  more  or 
less  severe  in  different  individuals. 

853.  Much  discussion  has  taken-place  respecting  the  causes  and  purposes  of 
the  Menstrual  flow ;  and  recent  inquiries  have  thrown  great  light  upon  them. 
The  state  of  the  female  generative  system,  during  its  continuance,  appears  to  be 
analogous  to  the  heat  or  periodic  sexual  excitement,  of  the  lower  animals ;  some 
of  which  have  a  sero-sanguinolent  discharge  at  that  period ;  and  among  many  of 
which,  the  ova  are  entirely  extruded  by  the  female  before  the  spermatic  fluid  of 
the  male  reaches  them,  this  occasionally  taking-place  even  in  Birds.  There  is 
good  reason  to  believe  that  in  the  Human  female  the  sexual  feeling  becomes 
stronger  at  the  period  of  menstruation ;  and  it  is  quite  certain  that  there  is  a 

The  fact  seems  to  be,  that  this,  like  other  periodic  phenomena  of  warm-blooded  animals, 
is  but  little  influenced  by  external  temperature,  simply  because  the  rate  of  growth  and 
development,  of  which  these  phenomena  are  the  exponents,  is  determined  by  the  tem- 
perature of  the  body  itself,  not  by  that  of  the  surrounding  medium.  Still  it  is  quite 
possible  that  external  warmth  may  have  a  slight  influence  in  determining  early  puberty ; 
since,  as  already  shown,  it  tends  to  maintain  a  somewhat  higher  degree  of  bodily  heat 
(2  427). 
'  See  Whitehead  "On  Abortion  and  Sterility,"  pp.  13-87. 


NATURE    AND    CAUSES    OF    MENSTRUAL    FLUX.         757 

greater  aptitude  for  Conception,  immediately  before  and  after  that  epoch,  than 
there  is  at  any  intermediate  period.  Observations  to  this  effect  were  made  by 
Hippocrates,  and  were  confirmed  by  Boerhaave  and  Haller;  indeed  coitus  imme- 
diately after  menstruation  appears  to  have  been  frequently  recommended  as  a 
cure  for  sterility,  and  to  have. proved  successful.  This  question  has  been  made 
the  subject  of  special  inquiry  by  M.  Raciborski;  who  affirms  that  the  exceptions 
to  the  rule — that  conception  occurs  immediately  before  or  after,  or  during  men- 
struation— are  not  more  than  6  or  7  per  cent.  Indeed,  in  his  latest  work  on 
this  subject,1  he  gives  the  details  of  15  cases,  in  which  the  date  of  conception 
could  be  accurately  fixed,  and  the  time  of  the  last  appearance  of  the  catamenia 
was  also  known ;  and  in  all  but  one  of  them,  the  correspondence  between  the 
two  periods  was  very  close.  Even  in  the  exceptional  case,  the  catamenia  made  their 
appearance  shortly  after  the  coitus ;  which  took  place  at  about  the  middle  of  the 
interval  between  the  two  regular  periods.  When  conception  occurs  immediately 
before  the  menstrual  period,  the  catamenia  sometimes  appear,  and  sometimes  are 
absent;  if  they  appear,  their  duration  is  generally  less  than  usual.  The  fact 
that  conception  often  takes-place  immediately  before  the  last  appearance  of  the 
catamenia  (and  not  after  it,  as  commonly  imagined),  is  one  well  known  to  prac- 
tical men. — Numerous  cases  have  been  collected  by  Mr.  Girdwood,  Dr.  Robert 
Lee,  MM.  Gendrin,  Negrier,  Raciborski,  and  others,  in  which  the  menstrual 
period  was  evidently  connected  with  the  maturation  and  discharge  of  ova;2  but 
the  most  complete  observations  yet  made  on  this  subject,  are  those  of  Dr.  Ritche 
(loc.  cit.).  He  states  that  about  the  period  of  puberty  a  marked  change  usually 
takes-place  in  the  mode  in  which  the  ovisacs  discharge  their  contents;  but  that 
this  change  does  not  necessarily  occur  simultaneously  with  the  first  appearance 
of  the  catamenia;  as  in  some  cases,  the  conditions  which  obtain  in  the  period 
before  puberty,  are  extended  into  that  of  menstruation.  The  ovaries  now  receive 
a  much  larger  supply  of  blood ;  the  ovisacs  show  a  great  increase  in  bulk  and 
vascularity,  so  that,  when  they  appear  at  the  surface  of  the  ovary,  they  present 
themselves  as  pisiform  turgid  elevations;  and  the  discharge  of  their  contents 
leaves  a  much  larger  cicatrix,  and  is  accompanied  by  an  effusion  of  blood  into 
their  cavity,  with  other  subsequent  changes,  to  be  presently  described.  It  would 
appear,  however,  that  although  such  a  discharge  takes  place  most  frequently  at 
the  menstrual  period,  yet  the  two  occurrences  are  not  necessarily  co-existent ;  for 
menstruation  may  take-place  without  any  such  rupture;  whilst,  on  the  other 
hand,  the  maturation  and  discharge  of  mature  ova  may  occur  in  the  intervals  of 
menstruation,  and  even  at  periods  of  life  when  that  function  is  not  taking-place. 
Perhaps  the  most  correct  general  statement  on  the  subject  would  be  this ;  that 
there  is  a  periodic  return  of  Ovarian  excitement,  which  tends  to  the  maturation 
and  extrusion  of  ovules,  though  it  may  not  always  reach  that  point ;  whilst  there 
is  also  a  periodic  turgescence  of  the  vessels  of  the  lining  membrane  of  the  Uterus, 
which  tends  to  the  production  of  a  decidual  membrane; — but  that  these  two 
periods,  though  usually  coincident,  are  not  necessarily  so;  and  that  either  change 
may  occur  without  the  concurrence  of  the  other. 

854.  The  duration  of  the  period  of  aptitude  for  procreation,  as  marked  by  the 
persistence  of  the  Catamenia,  is  more  limited  in  Women  than  in  Men,  usually 
terminating  at  about  the  45th  year;  it  is  sometimes  prolonged,  however,  for  ten 
or  even  fifteen  years  further;  but  cases  are  rare  in  which  women  above  50  years 
of  age  have  borne  children.  There  is  usually  no  menstrual  flow  during  preg- 
nancy and  lactation  ;  in  fact,  the  cessation  of  the  catamenia  is  generally  one  of 
the  first  signs,  indicating  that  conception  has  taken  place.  But  it  is  by  no  means 

1  "  Surla  Ponte  des  Mammiferes,"  Paris,  1844. 

3  Such,  at  least,  appears  to  be  the  legitimate  inference  from  the  state  of  the  Ovaries, 
but  the  cases  are  very  few  in  which  the  extruded  Ova  have  been  found  in  the  female  pass- 
ages. Two  such  cases  (one  of  them,  however,  not  altogether  satisfactory)  were  recorded 
by  Dr.  Letheby,  in  "  Philos.  Transact.,"  1852. 


758          OF    GENERATION  : — A  CTION    OF    THE    FEMALE. 

uncommon  for  them  to  appear  once  or  twice  subsequently  to  conception ;  and  in 
some  women  there  is  a  regular  monthly  discharge,  though  probably  not  of  the 
usual  character,  through  the  whole  period.  Some  very  anomalous  cases  are  on 
record,  in  which  the  catamenia  never  appeared  at  any  other  time  than  during 
pregnancy ;  and  were  then  regular.  The  absence  of  the  catamenia  during  lacta- 
tion is  by  no  means  constant,  especially  if  the  period  be  prolonged;  when  the 
menstrual  discharge  recurs,  it  maybe  considered  as  indicating  an  aptitude  for  con- 
ception; and  it  is  well  known  that,  although  pregnancy  seldom  recurs  during  the 
continuance  of  lactation,  the  rule  is  by  no  means  invariable. 

855.  The  function  of  the  Female,  during  the  coitus,  is  essentially  passive. 
When  the  sexual  feeling  is  strongly  excited,  there  is  a  considerable  degree  of  tur- 
gescence  in  the  erectile  tissue  surrounding  the  vagina,  and  composing  the  greater 
part  of  the  nymphae  and  the  clitoris;  and  there  is  an  increased  secretion  from  va- 
rious glandular  follicles.1     But  -these  changes  are  by  no  means  necessary  for  effec- 
tual coition;  since  it  is  a  fact  well  established,  that  fruitful  intercourse  may  take- 
place,  when  the  female  is  in  a  state  of  narcotism,  of  somnambulism,  or  even  of 
profound  ordinary  sleep.     It  has  been  supposed  by  some,  that  the  os  uteri  dilates, 
by  a  kind  of  reflex  action,  to  receive  the  semen  ;  but  of  this  there  is  no  evidence. 
The  introduction  of  a  small  quantity  of  the  fluid  just  within  the  vagina,  appears 
to  be  all  that  is  absolutely  necessary  for  conception ;  for  there  are  many  cases  on 
record,  in  which  pregnancy  has  occurred,  in  spite  of  the  closure  of  the  entrance 
to  the  vagina  by  a  strong  membrane,  in  which  but  a  very  small  aperture  existed. 
That  the  spermatozoa  make  their  way  towards  the  ovarium,  and  fecundate  the 
ovum  either  before  it  entirely  quits  the  ovisac  or  very  shortly  afterwards,  appears 
to  be  the  general  rule  in  regard  to  the  Mammalia ;  and  the  question  naturally 
arises, — by  what  means  do  they  arrive  there.     It  has  been  supposed  that  the 
action  of  the  cilia  which  line  the  Fallopian  tubes,  might  account  for  their  transit ; 
but  the  direction  of  this  is  from  the  ovaria  towards  the  uterus,  and  would  there- 
fore be  opposed  to  it.     A  peristaltic  action  of  the  Fallopian  tubes  themselves  may 
generally  be  noticed  in  animals  killed  soon  after  sexual  intercourse ;  and  in  those 
which  have  a  two-horned  membranous  uterus,  such  as  is  evidently  but  a  dilata- 
tion of  the  Fallopian  tube,  this  partakes  of  the  same  movement,  as  may  be  well 
seen  in  the  Rabbit;  but  this  peristaltic  action,  like  the  ciliary  movement,  is  from 
instead  of  towards  the  ovaries.     Among  the  tribes  whose  ora  are  fertilized  out  of 
the  body,  the  power  of  movement  inherent  in  the  spermatozoa  is  obviously  the 

•  means  by  which  they  are  brought  into  contact  with  the  ova ;  and  it  does  not 
seem  unreasonable  to  suppose,  that  the  same  is  the  case  in  the  higher  classes,  and 
that  the  transit  of  these  curious  particles,  from  the  vagina  towards  the  ovaries,  is 
effected  by  the  same  kind  of  action  as  that  which  causes  them  to  traverse  the 
field  of  the  microscope. — We  shall  now  consider  the  changes  in  the  Ovum  and 
its  appendages,  by  which  it  is  prepared  for  fecundation. 

856.  Up  to  the  period  when  the  Ovum  is  nearly  brought  to  maturity,  it  remains 
in  the  centre  of  the  ovisac  or  inner  layer  of  the  Graafian  follicle ;  and  it  is  sup- 
ported in  its  place  by  the  'membrana  granulosa/  which  is  continuous  with  its 

1  The  glands  of  Duverney,  which  have  been  very  accurately  described  by  Professor  Tie- 
demann  (1840),  and  subsequently  by  M.  Huguier  in  the  "Archives  d' Anatomic  "  (1847), 
seem  to  be  analogous  to  Cowper's  glands,  and  like  them  are  sometimes  wanting,  and  differ 
in  size.  In  advanced  age  they  are  said  to  diminish  in  size,  and  even  to  disappear.  They 
are  present  in  the  females  of  all  animals,  where  Cowper's  glands  exist  in  the  males.  They 
secrete  a  thick,  tenacious,  greyish-white  fluid,  which  is  emitted  in  large  quantity  at  the 
termination  of  the  sexual  act,  most  likely  from  the  spasmodic  contraction  of  the  constric- 
tor vaginae  muscle,  under  which  they  lie.  Its  admixture  with  the  male  semen  has  been 
supposed  to  have  some  connection  with  impregnation ;  but  no  proof  whatever  has  been 
given  that  any  such  admixture  is  necessary.  It  seems  not  improbable,  however,  that  it 
may  serve,  like  the  prostatic  fluid  of  the  male,  to  give  a  dilution  to  the  seminal  fluid  that 
is  favourable  to  its  action  ($  842).  These  glands  were  probably  known  to  the  ancients; 
jind  it,  is  doubtless  their  secretion,  which  Hippocrates  and  others  describe  as  the  female 
nemen. 


FORMATION    OF    THE    CORPUS    LUTEUM. 


759 


proligerous  disk.  The  movement  of  the  ovum  towards  the  surface,  which  has 
been  already  referred-to  as  a  part  of  the  changes  by  which  it  is  prepared  for  fecun- 
dation, appears  from  the  observations  of  Valentin  to  be  due  to  the  following  cause. 
In  the  immature  ovisac,  the  space  between  its  inner  layer  and  the  ovum  is  for  the 
most  part  filled-up  with  cells ;  these,  however,  gradually  dissolve-away,  especially 
on  the  side  nearest  the  surface  of  the  ovary ;  whilst  an  albuminous  fluid  is  effused 
from  the  deeper  part  of  the  ovisac,  which  pushes  the  residual  layer  (forming  the 
discus  proligerus)  before  it,  and  thus  carries  it  against  the  opposite  wall.  At  the 
same  time,  there  is  a  gradual  thinning-away  of  the  various  envelopes  of  the  Graa- 
fian  follicle,  as  well  as  of  its  own  walls,  in  the  situation  of  its  most  projecting  part; 
and  thus  it  is  preparing  to  give-way  at  that  point,  for  the  discharge  of  the  con- 
tained ovum.  Before  rupture  takes  place,  however,  the  ovisac  itself  undergoes  a 
considerable  change.  Its  walls  become  more  vascular  externally,  and  are  thick- 
ened on  their  interior  by  the  deposit  of  a  fleshy-looking  substance,  which,  in 
many  of  the  lower  Mammalia,  is  of  a  reddish  colour,  whilst  in  the  Human  female 
it  is  rather  of  a  yellowish  hue.  This  substance,  known  as  the  Corpus  luteum,  is 
at  first  entirely  composed  of  an  aggregation  of  cells  (Fig.  203),  and  may,  in  fact, 
be  considered  as  an  increased  development, 
or  hypertrophy,  of  the  '  membrana  gra- 
nulosa '  or  epithelial  lining  of  the  ovisac ; 
many  of  its  cells,  however,  especially  those 
in  apposition  with  the  enveloping  wall  of 
the  follicle,  undergo  a  more  or  less  com- 
plete transformation  into  fibres ;  and  thus 
a  gradual  transition  is  established  between 
the  cellular  substance  of  the  interior  of 
the  mass,  and  the  fibrous  stroma  of  the 
Ovarium  itself.1  In  most  domestic  quad- 
rupeds, this  growth,  which  sprouts  like  a 
mass  of  granulations  from  the  lining  of 
the  ovisac,  is  often  so  abundant,  if  the 


FIG.  203. 


Cells  forming  the  original  substance  of  th.3 
Corpus  Luteum. 


ovum  be  impregnated,  as  not  only  to  fill  the  cavity  of  the  ruptured  vesicle,  but 
even  to  protrude  from  the  orifice  on  the  surface  of  the  ovary;  this  orifice  subse- 
quently closes,  and  the  contained  growth  becomes  gradually  firmer,  its  colour 
changing  from  red  to  yellow.  In  the  Human  female,  however,  as  in  the  Sow, 
this  new  formation  is  at  first  less  abundant;  it  does  not  form  mammillary  projec- 
tions from  the  interior  of  the  ovisac,  but  lies  as  a  uniform  layer  upon  its  lining ; 
and  this  is  thrown  into  wrinkles  or  folds,  in  consequence  of  the  contraction  of  the 
ovisac  (Fig.  204,  a — cQ.  An  irregular  cavity  is  thus  at  first  left  in  the  interior 
of  the  ovisac,  after  the  discharge  of  the  ovum ;  but  this  gradually  diminishes, 
partly  in  consequence  of  the  increased  growth  of  the  yellow  substance,  and  partly 
owing  to  the  general  contraction  of  the  ovisac,  until  it  is  at  last  nearly  obliterated 
or  reduced  to  a  sort  of  stellate  cicatrix  (e — h).  An  effusion  of  blood  usually  takes 
place  into  this  cavity,  in  the  Human  female,  at  the  time  of  the  rupture  of  the 
ovisac ;  but  the  coagulum  which  is  left,  takes  no  share  in  the  formation  of  the 
yellow  body.  It  generally  loses  its  colouring  matter,  and  acquires  the  characters 
of  a  fibrinous  clot ;  and  this  may  either  form  a  sort  of  membranous  sac,  lining  the 
cavity;  or  it  may  become  a  solid  mass,  occupying  the  centre  of  the  stellate 
cicatrix.2 

I  By  some  observers,  as  Kb'lliker,  the  principal  part  of  the  new  growth  is  regarded  aa 
the  result  of  a  hypertrophy  of  the  internal  layer  of  the  fibrous  membrane  of  the  original 
follicle,  which,  even  before  the  expulsion  of  the  ovum,  becomes  loosened  in  texture  and 
augmented  in   thickness.     The  fact  seems  to  be,  that,  as  in  the  case  of  the  Malpighiau 
bodies  of  the  Spleen  (§  142  in.),  there  is  no  distinct  line  of  demarcation  between  thefibrout 
wall  and  the  cellular  contents  of  the  follicle. 

II  This  process  was  first  accurately  described  by  M.  Pouchet,  in  his  "  The"orie  Positive  de 
1'Ovulatiou  Spontane"e,"  1847. 


'60   OF  GENERATION: — ACTION  OF  THE  FEMALE 

FIG.  204. 


/  g  * 

Successive  stages  of  the  formation  of  the  Corpus  Lttteum,  in  the  Graafian  follicle  of  the  Sow, 
as  seen  in  vertical  section ; — at  a  is  shown  the  state  of  the  follicle  immediately  after  the  ex- 
pulsion of  the  ovum,  its  cavity  being  filled  with  blood,  and  no  ostensible  increase  of  its  epi- 
thelial lining  having  yet  taken-place ;  at  b,  a  thickening  of  this  lining  has  become  apparent; 
at  c,  it  begins  to  present  folds  which  are  deepened  at  d,  and  the  clot  of  blood  is  absorbed  pari 
passu,  and  at  the  same  time  decolorized;  a  continuance  of  the  same  process  as  shown  at  e,f, 
g,  h,  forms  the  Corpus  Luteum,  with  its  stellate  cicatrix. 

857  The  latter  part  of  the  history  of  the  Corpus  Luteum  is  greatly  influenced 
by  the  impregnation  or  non-impregnation  of  the  Ovum  whose  extrusion  it  has 
followed.  —  If  conception  do  not  take-place,  the  corpus  luteum  seldom  attains  a 
sifee  greater  than  that  of  a  small  pea,  and  is  very  commonly  less  than  this ;  and 
it  begins  to  diminish  about  the  time  of  the  next  menstruation,  its  shape,  which 
was  at  first  globular,  becoming  somewhat  collapsed  and  flattened.  This  diminu- 
tion is  due  in  the  first  instance  to  the  absorption  of  part  of  its  contained  coagu- 
lum,  which  usually  at  the  same  time  loses  part  of  its  colouring-matter;  but  con- 
temporaneously with  this,  there  is  an  increase  in  the  proper  yellow  substance, 
which  also  becomes  brighter  in  colour  from  the  presence  of  a  large  quantity  of 
oleaginous  matter  in  its  cells.  Soon,  however,  the  yellow  substance  becomes 
softer  and  more  friable,  showing  less  distinctly  the  markings  of  its  convolutions ; 
whilst  at  the  same  time  it  becomes  more  intimately  connected  with  the  neigh- 

[Fia.  205. 


Corpora  Lutea  of  different  periods :  B.  Corpus  luteum  of  about  the  sixth  week  aft*r  Im- 
pregnation, showing  its  plicated  form  at  that  period.  1.  Substance  of  the  ovary.  2.  Sub- 
stance of  the  corpus  luteum.  3.  A  grayish  coagulum  in  its  cavity;  after  Dr.  Patterson. 
A.  Corpus  luteum,  two  days  after  delivery.  D.  In  the  twelfth  week  after  delivery.  After 
Dr.  Montgomery.] 

bouring  tissues.     The  central  coagulum  becomes  a  faint,  whitish,  stellate  cica- 
trix ]  and  the  yellow  substance  assumes  various  irregularities  of  form,  and  gradually 


FORMATION    OF    THE    CORPUS    LUTEUM.  761 

decreases  in  size.  As  a  general  rule,  the  corpus  luteum  of  the  non-pregnant 
female,  is  reduced  within  six  or  eight  weeks  to  a  very  insignificant  size ;  but  it 
may  then  remain  almost  unchanged  for  many  months ;  so  that,  in  the  ovaries  of 
females  who  have  menstruated  regularly,  numerous  obsolete  corpora  lutea  may  be 
distinguished.  —  But  if,  on  the  other  hand,  the  discharged  ovum  should  be  fer- 
tilized, and  pregnancy  should  supervene,  the  corpus  luteum,  instead  of  reaching 
its  maximum  of  development  in  three  or  four  weeks  and  then  undergoing  atrophy, 
continues  to  develope  itself  for  a  considerable  period,  and  does  not,  in  fact, 
be-c-ome  very  decidedly  retrograde,  until  after  the  termination  of  gestation.  This 
difference  relates  not  only  to  its  size,  but  also  to  its  aspect  and  general  characters. 
Its  size  appears  to  be  usually  greatest  between  the  third  and  the  sixth  months  of 
pregnancy;  it  retains  its  globular  or  only  slightly-flattened  form;  and  it  con- 
tinues to  give  to  the  touch  a  sense  of  considerable  resistance  and  solidity.  The 
convoluted  wall  of  yellow  substance  becomes  much  thicker  in  proportion  to  the 
space  in  its  interior ;  so  that  whilst  in  the  non-impregnated  female  its  thickness 
never  exceeds  one-eighth  of  an  inch,  and  is  usually  much  less,  that  of  the  preg- 
nant female  measures  as  much  as  from  three-sixteenths  to  one-fourth  of  an  inch. 
This  substance,  moreover,  acquires  a  firmer  and  more  highly-organized  structure ; 
but  instead  of  presenting  an  increased  brightness  of  colour,  it  fades  to  a  dusky 
and  indefinite  hue.  As,  from  the  time  that  impregnation  takes  place,  the  periodi- 
cal activity  of  the  ovary  is  suspended,  no  new  vesicles  protrude  themselves  from 
its  surface  until  after  the  completion  of  gestation ;  and  even  those  which,  at  the 
date  of  conception,  happen  to  be  more  or  less  prominent,  appear  again  to  recede. 
Hence,  if  the  period  of  pregnancy  be  at  all  advanced,  the  corpus  luteum  is  not 
found,  like  that  of  menstruation,  in  company  with  unruptured  vesicles  in  active 
process  of  development.  After  parturition,  the  corpus  luteum  rapidly  dimi- 
nishes; though  its  characteristic  structure  is  still  to  be  distinguished  for  many 
months,  by  close  inspection.1 

1  See  especially  the  Prize  Essay  of  Dr.  J.  C.  Dalton,  "  On  the  Corpus  Luteum  of  Men- 
struation and  Pregnancy,"  in  the  "Transact,  of  the  American  Medical  Association  "  for 
1851,  and  separately  reprinted,  Philadelphia,  1851. 

[The  histories  and  observations  detailed  by  Dr.  Dalton  will  serve  to  show  how  very  im- 
perfect are  some  of  the  marks  which  various  writers  have  heretofore  laid  down  as  distin- 
guishing 'true'  from  'false'  corpora  lutea.  Dr.  Montgomery1  gives  seven  characteristics 
by  which,  he  says,  the  '  false,'  or  '  virgin '  corpora  lutea  may  be  recognized. 

'  I.   There  is  no  prominence  or  enlargement  of  the  ovary  over  them.' 

This  is  manifestly  incorrect,  for  the  corpora  lutea  of  menstruation  often  causes  a  notice- 
able protuberance  on  the  surface  of  the  ovary. 

'  II.  The  external  cicatrix  is  almost  always  wanting.'  According  to  Dr.  Dalton's  obser 
vations,  an  external  cicatrix  is  always  present  in  the  corpus  luteum  of  menstruation,  and, 
in  fact,  must  necessarily  be  so,  since  these  bodies  result  from  the  rupture  of  a  vesicle,  in 
the  same  manner  with  the  corpora  lutea  of  pregnancy. 

'III.  There  are  often  several  of  them  found  in  both  ovaries,'  &c.  This  is,  no  doubt, 
a  very  important  distinction,  since  we  never  find  more  than  one  corpus  luteum  of  preg- 
nancy at  a  time,  unless  in  cases  of  twins ;  and  then  the  two  corpora  lutea  are  evidently  of 
the  same  date,  and  have  the  same  aspect,  while  the  coexistent  corpora  lutea  of  menstrua- 
tion are  usually  in  many  different  stages  of  retrogression. 

'  IV.  They  present  no  trace  whatever  of  vessels  in  their  substance,  of  which  they  ar«, 
in  fact,  entirely  destitute,  and,  of  course,  cannot  be  injected.' 

According  to  Dr.  Dalton's  observations,  the  distribution  of  vessels  in  the  two  different 
kinds  of  corpora  lutea  is  the  same.  In  both,  the  substance  of  the  convoluted  wall  itself 
is  non-vascular ;  and  the  vessels  exist  only  in  the  interstices  of  the  folds.  This  fact  in 
very  easily  demonstrated  in  a  corpus  luteum  of  menstruation  when  completely  developed, 
as  the  convolutions  are  here  pretty  easily  separated  from  each  other;  but,  in  the  corpus 
luteum  of  pregnancy,  the  new  growth  from  the  internal  surface  of  the  vesicle  has  been  so 
abundant,  and  the  convolutions  are  consequently  pressed  so  firmly  together,  that  it  is  not 
always  easy  to  decide  whether  a  section  has  divided  the  substance  of  the  wall,  or  only  by 
accident  passed  between  two  convolutions ;  particularly  as  we  have  not  so  strong  a  con- 
trast in  colour,  to  assist  us,  between  the  yellow  and  red  vessels,  as  exists  in  the  corpus 
luteum  of  menstruation. 

1  "  Signs  and  Symptoms  of  Pregnancy,"  p.  245. 


762         OF    GENEKATION: — ACTION    OF    THE    FEMALE. 

858.  The  foregoing  differences  (whose  ordinary  existence  may  be  considered 
as  well-established,  although  it  may  not  be  affirmed  that  they  present  themselves 
characteristically  in  each  individual  case)  are  probably  to  be  attributed  to  the  in- 
creased determination  of  blood  which  takes  place  to  the  whole  Generative  appa- 
ratus, when  it  is  in  a  state  of  exalted  functional  activity.     It  is  a  question,  how- 
ever, of  much  scientific  interest,  and  one  that  occasionally  becomes  of  importance 
in  Juridical  investigations,  what  degree  of  resemblance  may  exist  between  the 
corpus  luteum  which  is  formed  after  the  mere  extrusion  of  an  ovule,  and  that 
which  has  been  modified  by  the  supervention  of  pregnancy.     For  it  is  unques- 
tionable that  an  unusual  development  of  the  fibro-cellular  substance  may  some- 
times occur  without  impregnation ;  whilst,  on  the  other  hand,  the  changes  which 
usually  follow  impregnation  may  take-place  so  much  less  characteristically  than  usual, 
that  the  corpus  luteum,  even  at  the  middle  period  of  pregnancy,  may  be  no  larger 
than  that  which  is  often  found  where  pregnancy  has  not  occurred.     These  varia- 
tions, which  seem  mainly  to  depend  upon  differences  in  the  degree  of  vascular 
excitement  of  the  ovaries,  accompanying  and  succeeding  the  extrusion  of  ova, 
render  it  impossible  to  draw  any  definite  line  of  demarcation,  by  which  we  may 
at  once  determine  what  are,  and  what  are  not,  the  results  of  conception ;  but  the 
following  practical  rules,  deduce-d  from  a  consideration  of  all  the  circumstances 
yet  known,  may  be  laid  down  for  the  guidance  of  those  who  find  it  desirable  to 
have  some  standard  of  judgment. — "1.  A  Corpus  Luteum,  in  its  earliest  stage 
(that  is,  a  large  vesicle  filled  with  coagulated  blood,  having  a  ruptured  orifice, 
and  a  thin  layer  of  yellow  matter  in  its  walls),  affords  no  proof  of  impregnation 
having  taken-place. — 2.  From  the  presence  of  a  Corpus  Luteum,  the  opening  of 
which  is  closed,  and  the  cavity  reduced  or  obliterated,  only  a  stellate  cicatrix  re- 
maining, also  no  conclusion  as  to  pregnancy  having  existed  or  fecundation  having 
occurred  can  be  drawn,  if  the  corpus  luteum  be  of  small  size,  not  containing  as 
much  yellow  substance  as  would  form  a  mass  the  size  of  a  small  pea.  —  3.  A 

'  similar  Corpus  Luteum  of  larger  size  than  a  common  pea,  would  be  strong  pre- 
sumptive evidence,  not  only  of  impregnation  having  taken  place,  but  of  preg- 
nancy having  existed  during  several  weeks  at  least }  and  the  evidence  would 
approximate  more  and  more  to  complete  proof,  in  proportion  as  the  size  of  the 
corpus  luteum  was  greater."  ! 

859.  Since  the  discharge  of  matured  Ova  from  the  ovaries  takes-place  as  inde- 
pendently of  sexual  intercourse  in  the  Human  female  (and  in  the  Mammalia 
generally),  as  it  does  in  those  animals  whose  ova  are  fertilized  out  of  the  body, 
it  seems  unnecessary  that  the  seminal  fluid  should  reach  the  ovarium  in  order  to 
effect  the  fertilization  of  the  ova,  since  this  end  may  be  answered  by  the  contact 
of  the  two  in  the  Fallopian  tubes,  or  even  in  the  Uterus  itself.     From  the  ex- 
periments of  Bischoff,  however,  it  appears  that  in  rabbits,  bitches,  and  probably 

'  V.  Their  texture  is  sometimes  so  infirm  that  it  seems  to  be  merely  the  remains  of  a 
coagulum,'  &c.  This  is  frequently  a  good  distinguishing  mark. 

'VI.  In  figure,  they  are  often  triangular,  or  square,  or  of  some  figure  bounded  by 
straight  lines.'  This  has  already  been  seen  to  be  an  appearance  frequently  presented  by 
the  corpus  luteum  of  menstruation,  at  an  advanced  period  of  atrophy. 

'VII.  They  never  present  either  the  central  cavity,  or  the  radiated  or  stelliform  white 
lines  which  results  from  its  closure.'  Dr.  Dal  ton  says  that  this  last  distinction  is  so  exceed- 
ingly incorrect  that  it  is  difficult  to  understand  how  it  could  have  been  laid  down  by  such 
an  observer  as  Dr.  Montgomery.  The  corpus  luteum  of  menstruation  always  presents  a 
central  cavity,  t.  e.,  a  space  included  by  the  convoluted  wall,  which  space  is  filled  by  a 
coagulum ;  and,  as  the  whole  yellow  body  becomes  atrophied,  the  coagulum  is  transformed 
into  a  radiated  or  stelliform  cicatrix,  more  or  less  coloured  with  blood,  according  to  the 
rapidity  with  which  the  absorption  of  the  hsematin  has  proceeded. 

There  can  be  no  doubt,  therefore,  of  the  existence  of  certain  distinct  and  reliable  marks 
by  which  the  corpus  luteum  may  be  recognized  as  a  sign  of  pregnancy,  and  distinguished 
?rom  all  other  appearances,  either  morbid  or  physiological,  to  be  met  with  in  the  ovary." 
-ED.] 

1  See  Dr.  Baly's  "Supplement  to  Miiller's  Physiology,"  p.  57. 


IMPBEGNATION    OF    THE    OVUM.  763 

in  most  other  Mammalia,  sexual  union  usually  takes-place  previously  to  the 
escape  of  the  ova  from  the  ovary,  and  that  sufficient,  time  often  elapses  for  the 
seminal  fluid  to  reach  the  ovary  before  their  extrusion  occurs  :  in  such  cases, 
therefore,  it  would  seem  probable  that  fecundation  is  effected  at  the  ovary  itself. 
That  such  occasionally  happens  in  the  Human  female,  seems  to  be  unequivocally 
proved  by  the  occurrence  of  tubal  or  even  of  ovarian  foetation ;  the  ovum  having 
received  the  fertilizing  influence  immediately  upon  quitting  the  ovisac,  or  even 
before  it  has  entirely  extricated  itself  from  the  ovary,  and  having  been  in  some 
way  checked  in  its  transit  towards  the  uterus,  so  that  its  development  has  taken- 
place  in  the  spot  at  which  it  has  been  arrested.  It  is  affirmed  by  Bischoff  that 
by  the  time  the  ovum  reaches  the  uterus,  or  even  the  lower  end  of  the  Fallopian 
tube,  its  capacity  for  impregnation  is  lost ;  but  this  assertion  chiefly  rests  on  the 
cessation  of  sexual  desire,  observed  in  those  animals  in  which,  after  death,  the 
ova  were  found  in  these  situations.  There  is  every  reason  to  believe  that  this  is 
not  the  case  in  the  Human  female ;  for  although  the  sexual  desire  may  be  the 
strongest  about  the  period  of  the  maturation  and  escape  of  the  ova,  yet  it  is  by 
no  means  wanting  at  other  times  ;  and  the  occasional  occurrence  of  cases  in  which 
impregnation  has  taken-place  from  a  single  coitus  in  the  middle  of  tie  interval 
between  the  menstrual  periods,  shows  either  that  the  ovum  may  retain  its  ca- 
pacity for  impregnation  for  some  time  after  its  escape  from  the  ovary,  or  that  its 
maturation  and  extrusion  are  not  by  any  means  invariably  coincident  with  the 
menstrual  period.1  —  The  ova,  when  set-free  from  the  ovaries  by  the  rupture  of 
the  ovisacs  and  the  giving-way  of  their  several  envelopes,  are  received  by  the  fim- 
briated  extremities  of  the  Fallopian  tubes,  which,  during  the  period  of  sexual 
excitement,  appear  to  be  closely  applied  to  the  surface  of  the  ovaries.  Their 
conveyance  along  the  Fallopian  tubes  is  probably  due  in  part  to  the  peristaltic 
movement  of  their  walls,  and  in  part  to  the  action  of  the  cilia  which  clothe  their 
internal  surface. 

860.  The  object  of  the  changes  which  have  been  already  described,  is  to  bring 
the  Ovum  within  the  reach  of  the  fecundating  influence,  and  to  convey  it  into 
the  uterus  after  it  has  been  fertilized :  we  have  now  to  consider  the  changes  of 
the  Ovum  itself,  which  take-place  during  the  same  epoch.  —  At  about  the  same 
period  that  the  ovum  moves  towards  the  periphery  of  the  Graafian  follicle,  the 
germinal  vesicle  moves  towards  the  periphery  of  the  yolk;  and  it  always  takes- 
up  its  position  at  the  precise  point  of  the  zona  pellucida  which  is  nearest  the 
ovisac,  and  which  is  closest,  therefore,  to  the  surface  of  the  ovary.  Moreover, 
the  germinal  spot  is  always  on  that  part  of  the  germinal  vesicle,  which  is  in 
closest  contact  with  the  zona  pellucida.  Thus,  the  germinal  spot  is  very  near  the 
exterior  of  the  ovary;  but  it  is  separated  from  the  peritoneal  coat  of  the  latter, 
by  a  thin  layer  of  its  stroma  forming  the  external  wall  of  the  Graafian  follicle,  by 
the  ovisac  forming  its  internal  membrane,  and  by  the  zona  pellucida.  As  soon 
as  these  give  way,  there  is  nothing  to  prevent  the  spermatozoa  from  coming  into 
direct  contact  with  the  ovum,  even  before  it  quits  the  ovisac.  That  such  contact 
is  an  essential  condition  of  fecundation,  there  is  every  reason  to  believe ;  although, 
as  to  the  precise  manner  in  which  it  operates,  we  are  at  present  in  the  dark. 
There  can  be  no  doubt  that  it  is  in  the  contact  of  the  spermatozoa  with  the  ovum 
(§  845),  and  in  the  changes  which  occur  as  the  immediate  consequence  of  that 

1  See  a  case  of  this  kind  recorded  by  Dr.  Oldham  in  the  "  Medical  Gazette,"  July  13, 
1849. — Instances  are  certainly  not  unfrequent,  in  which  conception  has  taken  place  five  or 
sis  days  after  the  conclusion  of  the  menstrual  period ;  the  Author  has  himself  known  one 
in  which  this  occurred,  after  the  menstrual  flow  itself  had  persisted  for  a  week.  It  had 
been  urged  that  the  known  fertility  of  the  Jewish  females,  who  abstain  from  sexual  inter- 
course for  eight  days,  or  even  thirteen  days,  after  the  termination  of  the  catamenia,  ia 
opposed  to  the  idea  that  the  menstrual  period  is  that  of  'heat;'  but  there  is  reason  to 
believe  that  this  is  to  be  accounted-for  in  another  way, — namely,  by  the  usual  occurrence 
of  conception  from  intercourse  immediately  before  the  access  of  the  catamenia.  (See  Air. 
Girdwood,  in  the  "Lancet,"  Dec.  14,  1844.) 


764      OF  GENERATION:  —  ACTION   OF  THE  FEMALE. 

contact,  that  the  act  of  Fecundation  essentially  consists.  The  most  recent  ob- 
servations of  the  late  Mr.  Newport  upon  the  process  of  impregnation  of  the  Prop; 
(some  of  which  the  Author,  through  the  kindness  of  Mr.  N.,  had  the  oppor- 
tunity of  verifying),  show  that  the  spermatozoa  become  imbedded  in  the  gelati- 
nous envelope  of  the  ovum,  within  a  few  seconds  after  they  come  into  contact 
with  it;  and  that  they  then  absolutely  pass  through  the  vitelline  membrane,  into 
the  interior  of  the  Ovum,1  where  they  probably  undergo  a  gradual  diffluence; 
and  thus  the  product  of  the  '  sperm-cell '  may  be  absorbed  into  the  '  germ-cell/ 
and  may  intermingle  with  its  contents,  the  Spermatozoon  being  nothing  else  than 
an  embodiment  of  the  fertilizing  material  developed  within  the  sperm-cell,  which 
is  endowed  with  a  temporary  power  of  movement  in  order  that  it  may  find  its 
way  to  the  Ovum.  It  has  been  remarked  by  Mr.  Newport,  that  Spermatozoa 
whose  spontaneous  motility  has  ceased,  no  longer  possess  the  fecundating  power; 
arid  this  fact  concurs  with  other  phenomena  to  indicate,  that  it  is  not  only  a  cer- 
tain material,  but  a  vital  force  of  which  that  material  is  (so  to  speak)  the 
vehicle,  which  is  required  to  effect  this  most  important  operation. 

861.  The  precise  share  which  the  Germinal  Vesicle  performs,  in  the  changes 
which  take-place  in  the  ovum  about  the  period  of  fecundation,  has  not  yet  been 
satisfactorily  determined.  According  to  Dr.  Barry,  (loc.  cit.),  the  germinal  vesicle 
becomes  filled  with  a  new  development  of  cells,  which  sprout,  as  it  were,  from  its 
nucleus  (the  germinal  spot);  and  after  fecundation,  a  pair  of  cells  is  seen  in  the 
space  previously  occupied  by  the  pellucid  centre  of  the  nucleus,  which  is  deve- 
loped at  the  expense  of  the  rest,  and  is  the  true  foundation  of  the  embryonic 
structure.  This  view  is  to  a  certain  extent  confirmed  by  the  observations  of 
Wagner  on  the  ova  both  of  Frogs  and  Mammalia,  and  by  those  of  Vogt  on  those 
of  the  Rana  obstetricans  ;  both  of  which  lead  to  the  belief  that  such  a  process  of 
cell  formation  does  take-place  within  the  germinal  vesicle,  but  that,  instead  of  the 
further  development  being  carried-on  within  the  germinal  vesicle,  as  maintained 
by  Dr.  Barry,  this  ruptures  and  sets-free  the  cells  that  had  been  developed  in  its 
interior,  which  are  now  dispersed  through  the  yolk,  whose  ulterior  changes  take- 
place  under  their  influence.  Mr.  Newport's  view  is  nearly  the  same  as  this ;  and 
he  states  that,  in  the  Frog,  this  dissolution  of  the  germinal  vesicle  and  diffusion 
of  its  contents  take-place  as  a  preparation  for  fecundation,  and  not  in  consequence 
of  it.2  That  the  germinal  vesicle  is  no  longer  to  be  seen  when  the  metamorphoses 
of  the  yolk  have  commenced,  is  now  universally  admitted ;  but  with  regard  to  the 
antecedent  process  just  described,  there  is  still  a  want  of  accordance  amongst  Em- 
bryologists,  its  existence  being  altogether  denied  by  Bischoff,  who  maintains  that 
the  germinal  vesicle  simply  dissolves-away  shortly  after  coition.  The  Author  is 
strongly  inclined  to  believe,  however,  from  bis  own  observations,  as  well  as  from 
d  priori  considerations  based  on  the  history  of  Vegetable  fertilization,  that  there 
is  a  development  of  cells  within  the  germinal  vesicle,  at  the  time  of  its  matura- 
tion ;  and  that  it  is  by  the  influence  of  the  spermatic  fluid  upon  one  of  these  cells, 
after  it  has  been  set-free  in  the  midst  of  the  yolk  by  the  rupture  or  diffluence  of 
the  germinal  vesicle,  that  the  first  cell  of  the  embryonic  fabric  is  generated. 

862.  Having  thus  noticed  the  principal  points  of  the  history  of  the  develop- 
ment and  impregnation  of  the  Ovum,  we  shall  proceed  to  consider  the  provisions 
made  for  the  Nutrition  of  the  Embryo,  through  the  Generative  apparatus  of  its 
fern-ale  Parent,  up  to  the  time  of  parturition ;  deferring  the  history  of  its  own  De- 
velopment for  that  separate  consideration  which  the  importance  of  this  subject 
demands  (Sect.  4). — About  the  time  that  the  ovum  is  leaving  the  ovary,  the  cells 

1  "Philos.  Transact.,"  1853,  pp.  266— 281. —  Prof.  Bischoff,  the  highest  authority  on 
this  subject,  who  had  disputed  the  validity  of  all  previous  observations  on  the  penetration 
of  the  Spermatozoa  into  the  interior  of  the  Ovum,  has  fully  confirmed  those  of  Mr.  New- 
port; whose  lamented  death  prevented  him  from  enjoying  the  satisfaction  which  this  tes- 
timony to  his  accuracy  would  have  afforded  him.  —  See  also  Dr.  Barry  in  "Philos.  Tran- 
sact," 1840,  p.  533;  and  Dr.  Ransome  in  "  Proceedings  of  Royal  Society,"  Nov.  23,  1854. 

-  "Philos.  Transact.,"  1851,  p.  178. 


IMPREGNATION    OF    THE    OVUM.        ,  766 

of  the  proligerous  disk  which  immediately  surrounds  the  zona  pellucida  become 
club-shaped ;  their  small  ends  being  applied  to  the  surface  of  the  ovum,  so  as  to 
give  it  somewhat  of  a  stellate  appearance.  According  to  Bischoff,  these  cells  en- 
tirely disappear  from  the  ovum  of  the  Rabbit,  as  soon  as  it  has  entered  the  Fallo- 
pian tube  :  whilst  in  the  Bitch  they  become  round,  and  continue  to  invest  the 

[Tie.  206. 


A.  An  ovarium  ovum  from  a  Bitch  in  heat,  exhibiting  the  elongated  form  and  stellate  ar- 
rangement of  the  cells  of  the  discus  proligerus  or  membrana  granulosa  around  the  zona  pel- 
lucida. B.  The  same  ovum  after  the  removal  of  most  of  the  club-shaped  cells.] 

ovum  in  this  form  throughout  its  whole  transit  to  the  uterus.  During  its  pas- 
sage, the  ovum  acquires  a  sort  of  gelatinous  envelope,  which  is  enclosed  in  a  mem- 
brane of  fibrous  texture,  termed  the  Chwwn.  This  envelope  is  probably  of  an 
albuminous  nature  in  reality,  corresponding  with  the  '  white  '  of  the  Bird's  egg; 
whilst  the  fibrous  texture  of  the  chorion  seems  to  be  produced,  like  the  membranous 
basis  of  the  egg-shell  of  the  bird  (PRiNC.  OF  GEN.  PHYS.,  Am.  Ed.),  by  the  exu- 
dation of  fibrin  from  the  lining  membrane  of  the  Fallopian  tube  or  oviduct  The 
outer  layer  of  this  envelope,  in  the  egg  of  the  Bird,  is  consolidated  by  the  depo- 
sition of  particles  of  carbonate  of  lime  in  its  areolse ;  and  none  of  it  undergoes 
any  further  organization.  The  Chorion  of  the  Mammal,  on  the  other  hand,  is 
destined  to  undergo  changes  of  a  much  higher  order ;  which  adapt  it  for  partici- 
pating, to  a  most  important  degree,  in  the  nutrition  of  the  included  embryo. 
The  first  of  these  changes  consists  in  the  extension  of  the  cellular  surface  of  the 
membrane  into  a  number  of  villou#  prolongations,  which  give  it  a  spongy  or 
shaggy  appearance  (Fig.  212);  these  serve  as  absorbing  radicles,  and  form  the 
channel  through  which  the  embryo  is  nourished  by  the  fluids  of  the  parent,  un- 
til a  more  perfect  communication  is  formed  by  the  subsequent  extension  of  ves- 
sels into  them  (§  865). 

863.  We  have  now  to  speak  of  the  changes  in  the  Uterus,  which  take-place  in 
consequence  of  Conception,  and  which  prepare  it  to  receive  the  ovum.  Of  these 
the  most  important  is  the  formation  of  the  Membrana  Decidua,  so  called  from 
its  being  cast-oiF  at  each  parturition.  This  membrane  has  been  usually  sup- 
posed to  be  a  new  formation ;  and  has  been  described  as  originating  in  coagulable 
lymph  thrown-out  on  the  inner  surface  of  the  uterus,  into  which  vessels  are  pro- 
longed from  the  subjacent  substance.  It  appears,  however,  from  the  researches  of 
Profrs.  Sharpey  and  Weber,1  that  this  is  not  the  true  account  of  it;  and  that  the 
Decidua  Vera  is  really  composed  of  the  inner  portion  of  the  Mucous  membrane 
itself,  which  undergoes  a  considerable  change  in  its  character.  The  mucous  mem- 
brane of  the  uterus  possesses  on  its  free  surface,  a  tubular  structure  (Figs.  207, 208) ; 
not  very  unlike  that  which  has  been  described  as  existing  in  the  lining  membrane 
of  the  stomach  (§  94).  This  tubular  portion  becomes  thickened  and  increased  in 
vascularity,  within  a  short  time  after  conception ;  and  when  the  inner  surface  of 
a  newly-impregnated  Uterus  is  examined  with  a  low  magnifying  power,  the  ori- 
fices of  its  tubes  are  very  distinctly  seen,  being  lined  with  a  white  epithelium. 
The  blood-vessels  form  a  very  minute  network,  which  extends  in  loops  from  the 
1  "Mullet's  Elements  of  Physiology,"  pp.  1574-1580 


OF  GENERATION:  —  ACTION  OF  THE  FEMALE. 

FIG.  207. 


Section  of  the  Lining  Membrane  of  a  Human  Uterus  at  the  period  of  commencing  pregnancy, 
twice  the  natural  size;  showing  the  arrangement  and  other  peculiarities  of  the  glands  d,  d,  d, 
with  their  orifices,  a,  a,  a,  on  the  internal  surface  of  the  organ. 

subjacent  portion  of  the  membrane.  According  to  the  observations  of  Prof. 
Goodsir,1  the  interfollicular  spaces  also  are  crowded  with  nucleated  particles;  and 
it  is  to  the  development  of  this  interfollicular  substance,  a,s  well  as  to  the  en- 


FIG.  208. 


[Fia.  209. 


Two  thin  segments  of  Human  De- 
cidua;  after  recent  impregnation, 
viewed. on  a  dark  ground ;  they  show 
the  openings  on  the  surface  of  the 
membrane.  A  is  magnified  six  diam- 
eters and  B  twelve  diameters.  At  1, 
the  lining  of  epithelium  is  seen  with- 
in the  orifices ;  at  2,  it  has  escaped. 
From  Dr.  Sharpey  (xxxii.).] 


A  portion  of  Fig.  207  more  enlarged, 
showing  the  convoluted  extremities  of  the 
tubular  glan dulse. 

largement  of  the  follicles  themselves,  and  the  copious  development  of  epithelial 
cells  in  their  interior,  that  the  mucous  membrane  in  this  condition  owes  its  in- 
creased thickness.  This  increased  development  appears  to  have  reference  in  part 
to  the  temporary  nutrition  of  the  Ovum,  and  in  part  to  the  further  evolution  of 
the  decidual  substance  itself  in  the  formation  of  the  Placenta.  The  cavity  of  the 
Uterus  shortly  becomes  filled  with  a  fluid,  evidently  poured-out  from  the  follicles 
in  its  walls,  and  containing  a  large  number  of  nucleated  cells;  and  in  this  the 
villi  of  the  chorion  imbed  themselves,  obviously  for  the  purpose  of  deriving  from 
it  the  materials  required  for  the  development  of  the  embryonic  structures.  These 
villi  are  easily  traced  in  the  Bitch  (as  Dr.  Sharpey  first  pointed-out)  into  the 
rnouths  of  the  uterine  glandulae,  some  of  which  are  composite  in  their  structure,  a 
*'  Anatomical  and  Physiological  Observations,"  chap.  is. 


FORMATION    OF    THE    DECIDUA.  767 

single  outlet  being  common  to  a  number  of  follicles  ;  but  they  have  not  yet  been 
so  traced  in  the  Human  subject. 

864.  The  Deciduous  membrane  is  found  at  a  later  period  to  consist  of  two 
layers ;  the  Decidua  vera  lining  the  uterus,  and  the  Decidua  reflexa  covering  the 
exterior  of  the  ovum.  Regarding  the  origin  of  this  second  layer,  there  has  been 
a  good  deal  of  difference  of  opinion.  The  doctrine  first  propounded  by  Dr.  W. 
Hunter,  which  is  indicated  by  the  name  he  bestowed  upon  the  membrane,  was 
tha-t  the  '  decidua  reflexa '  is  a  portion  of  the  true  decidua,  which  has  been  pushed 
before  the  ovum  at  its  entrance  into  the  uterus ;  it  being  supposed  that  the  true 
decidua  forms  a  completely  closed  sac  (like  that  of  a  serous  membrane),  against 
the  outside  of  which  the  ovum  is  applied,  so  that  it  comes  to  be  invested  by  a 
double  layer  of  it,  as  the  heart  is  by  the  pericardium,  or  the  lungs  by  the  pleura. 
But  this  view  is  negatived  by  a  number  of  considerations.  For,  in  the  first  place, 
the  original  decidua  does  not  form  the  closed  sac  which  this  supposition  involves, 
but  extends  (like  the  mucous  membrane  of  which  it  is  a  metamorphosed  form) 
into  the  Fallopian  tubes ;  and  the  ovum,  at  its  entrance  into  the  uterus,  really 
lies  upon  its  internal  surface.  But  again,  the  texture  of  the  two  layers  is  very 
different;  for,  as  was  first  pointed-out  by  Prof.  Goodsir  (loc.  cit.),  the  decidua 
reflexa  is  almost  entirely  composed  of  cells,  exhibiting  few  or  none  of  the  orifices 
of  the  glandular  follicles  which  are  characteristic  of  the  decidua  vera,  except  near 
the  part  where  the  two  layers  are  continuous.  According  to  the  observations  of 
M.  Coste,  however,  there  is  a  considerable  resemblance  between  the  two  layers  at 
an  early  period ;  and  he  considers  the  following  to  be  the  mode  in  which  the 
second  investment  is  formed.  When  the  ovum  enters  the  uterus,  it  becomes  par- 
tially imbedded  in  the  substance  of  the  decidua,  which  is  as  yet  quite  soft  (Fig- 
210);  and  this,  receiving  an  increased  nutrition  at  the  part  with  which  the  ovum 
comes  into  contact,  grows-up  around  it,  very  much  after  the  manner  in  which  the 
fleshy  granulations  grow-up  around  the  pea  imbedded  in  a  caustic  issue.  This 
extension  of  the  decidual  substance  continues  (Fig.  211),  until  it  has  completely 

FIG.  210.  FIG.  211. 


First  stage  of  the  formation  of  the  Decidua  More  advanced  stage  of  Decidua  rejiexa. 

reflexa  around  the  Ovum. 

enveloped  the  ovum ;  and  it  is  thus,  according  to  him,  that  the  decidua  reflexa  la 
formed,  in  continuity  with  the  decidua  vera.1  As  the  ovum  increases  in  size,  the 
cavity  between  the  decidua  vera  and  the  decidua  reflexa  gradually  diminishes ;  and 
by  the  end  of  the  3d  month  the  two  layers  come  into  contact,  and  are  henceforth 
scarcely  or  not  at  all  distinguishable. 

865.  The  surface  of  the  Ovum,  thus  surrounded  by  the  double  layer  of  the 

1  This  doctrine  was  first  announced  by  M.  Coste  in  a  communication  to  the  Parisian 
Academy  of  Sciences,  on  the  basis  of  observations  on  two  Uteri  at  the  20th  and  25th  days 
of  gestation.  (See  "Comptes  Rendus,"  Mai  24,  1847.)  It  seems  to  be  that  which  ia 
altogether  most  in  harmony  with  observed  facts :  and  especially  with  those  noticed  by  Pro- 
fessors Sharpey  and  Weber. — See,  also,  the  Memoir  of  M.  Robin,  on  the  Mucous  Mem- 
brane of  the  Uterus,  in  the  "  Archiv.  Ge"n.  de  Me'd.,")  4e  Ser.,  torn.  xvii.  xviii. 


768      OF  GENERATION:  —  ACTION  OF  THE  FEMALE. 

deciduous  membrane,  is  rendered  shaggy  by  the  growth  of  villous  tufts  from  the 
surface  of  its  investing  Chorion  (Fig.  212).     Each  of  these  tufts,  as  was  first 

pointed-out  by  Prof.  Goodsir  (loc.  cit.),  is  com- 
FIG.  212.  posed  of  an  assemblage  of  nucleated  cells,  which 

are  found  in  various  stages  of  development ;  and 
these  are  always  enclosed  within  a  layer  of  base- 
ment-membrane, which  seems  to  be  itself  com- 
posed of  flattened  cells  united  by  their  edges. 
At  the  free  extremity  of  each  villus  is  a  bulbous 
expansion,  the  cells  composing  which  are  ar- 
ranged round  a  central  spot;  and  it  is  at  this 
point  that  the  most  active  processes  of  growth 
take-place,  the  villus  elongating  by  the  develop- 
ment of  new  cells  from  its  germinal  spot,  and 
(like  the  spongiole  of  the  plant)  drawing-in  nu- 
triment from  the  soil  in  which  it  is  imbedded. 
— In  its  earliest  grade  of  development,  the  cho- 
rion  and  its  villi  contain  no  vessels;  and  the 
fluid  drawn-in  by  the  tufts  is  communicated  to 
the  embryo,  by  the  absorbing  powers  of  the  ger- 
minal membrane  of  the  latter.  But  when  the 
Entire  Human  Ovum  of  8th  week,  tufts  are  penetrated  by  blood-vessels,  and  their 
sixteen  lines  in  length  (not  reckoning  communication  with  the  embryo  becomes  more 
X -o";^6—  direct  the  means  by  which  they  communicate 
shaggy  by  the  growth  of  tufts.  with  the  parent  are  found  to  be  still  essentially 

the  same ;  namely,  a  double  layer  of  nucleated 

cells,  one  layer  belonging  to  the  foetal  tuft,  and  the  other  to  the  vascular  maternal 
surface.     It  is  from  these  elements  that  the  Placenta  is  formed. 

866.  The  first  stage  in  this  process  consists  in  the  extension  of  the  Foetal 
vessels  into  the  villi  of  the  CLorion  over  its  entire  surface,  in  the  manner  here- 
after to  be  detailed  (§  893) ;  so  that  the  nutriment  which  these  villi  imbibe,  in- 
stead of  being  merely  added  to  the  albuminous  fluid  surrounding  the  yolk-bag,  is 
now  convened  directly  to  the  embryo.  This — the  earliest  and  simplest  mode  by 
which  the  Foetus  effects  a  new  connection  with  the  parent — is  the  only  one  in 
which  it  ever  takes-place  in  the  lower  Mammalia,  which  are  hence  properly  de- 
signated as  <  non-placental/  rather  than  as  ovo-viviparous.  In  the -higher  Mam- 
malia, however,  there  soon  occurs  a  great  extension  of  the  vascular  tufts  of  the 
fotal  chorion,  at  certain  points;  and  a  corresponding  adaptation,  on  the  part  of 
the  uterine  structure,  to  afford  them  an  increased  supply  of  nutritious  fluid. 

These   specially-prolonged    portions   are 

FIG.  213.  scattered,  in  the  Kuminantia  and  some 
other  Mammalia,  over  the  whole  surface 
of  the  chorion,  forming  what  are  termed 
the  '  cotyledons ;'  but  in  the  higher 
orders,  and  in  Man,  they  are  concentrated 
in  one  spot,  forming  the  Placenta.  In 
some  of  the  lower  tribes,  the  maternal 
and  the  foetal  portions  of  the  placenta, 
may  be  very  easily  separated;  the  for- 
mer  consisting  of  the  thickened  Decidua ; 

„    ..        ,  t,      ,,.  and  the   latter  being  composed   of  the 

Portion   of  the  ultimate  ramifications  of  the         ,  ,         ,  .  P . 

Umbilical  vessels,  forming  the  Fatal  Villi  of  the  PToloiaged   and   ramifying   vascular    tufts 

Placenta.  of  the  Chorion,   dipping-down    into   it. 

But   in    the    Human  placenta,  the   two 

elements  are  mingled  together  through  its  whole  substance. — On  looking  at  the 
foetal  surface    of   the  Human  placenta,  we  perceive  that  the  umbilical  vessels 


FORMATION  OF  THE  PLACENTA. 


7G9 


FIG.  214. 


diverge  in  every  direction  from  the  point  at  which  they  enter  it;  and  their  sub- 
divisions form  a  large  mass  of  capillaries,  arranged  in  a  peculiar  manner  (Figs, 
213,  214),  and  constituting  what  are 
«nown  as  the  foetal  villi.  Each  villus 
/ontains  one  or  more  capillary  loops, 
x>mmunicating  with  an  artery  on  one 
*ide,  and  with  a  vein  on  the  other ;  but 
<he  same  capillary  may  pass  into  several 
villi,  before  re-entering  a  larger  vessel. 
The  capillaries  of  the  villi  are  covered, 
as  in  the  chorion,  by  a  layer  of  cells 
(Fig.  214,  a,  a,  Fig.  215,/),  inclosed  in 
basement-membrane  (e) ;  but  the  foetal 
tuft  thus  formed  is  inclosed  in  a  second 
series  of  envelopes  (Fig.  215,  a,  b,  c), 
derived  from  the  maternal  portion  of  the 
placenta, — a  space  (rf)  being  left,  how- 
ever, between  the  two,  at  the  extremity 
of  the  tuft. 

867.  Whilst  the  foetal  portion  01"  the 
Placenta  is  thus  being  generated  by  tnt, 
extension  of  the  vascular  tufts  of  the 
Chorion,  the  maternal  portion  is  formed 
by  the  enlargement  of  the  vessels  of  the 
'Decidua,  between  which  they  dip-down. 
"  These  vessels  assume  the  character  of 
sinuses ;  and  at  last  swell-out  (so  to 
speak)  around  and  between  the  villi;  so 

that  finally  the  villi  are  completely  bound-  „ 

-,    i         ,  i  .  .  ,     to»  n  part  or  the  .Placenta,  highly  magnified. — 

up  or  covered  by  the  membran-e  which  ft>  0>  its  cellular  covering.  ££^  &  ,       d 

constitutes   the  walls   of  the  vessels,  this  vessels;  c,  c,  its  b^eis  of  connective  tissue. 
membrane  following  the  contour  of  all 
the  villi,  and  even  passing  to  a  certain 
extent  over  the  branches  and  stems  of 
the  tufts.     Between  this  membrane,  or 
wall   of   the   enlarged   decidual   vessels, 
and  the  internal  membrane  of  the  villi, 
there  still  remains  a  layer  of  the  cells 
of  the  decidua."       In    this    manner   is 
formed  the  maternal  portion  of  the  pla- 
centa, which   may   be    regarded    in    its 
adult   State  (as   was  well    pointed-OUt    by       Extremity  of  a  Placental  ViJlu*:-**,  exter- 
Dr.  J.  Reid  2)  in  the  light  of  a  large  sac  nal  membrane  of  the  villus,  continues   with 
formed   by  a  prolongation  of  the  inner  the  lininS  membrane  of  the  vascular  system  of 
coat  Of  the   Uterine  vessels;    against  the  fhe  mother;  6,  external  cells  of  the  villus  be. 
r.     ,  .   ,  ',    *      f  longing  to  the  placental  decidua ;  c,  c,  germinJ 

foetal  surface  of  which  sac,  the  tufts  just  centres  of  the  external  cells .  rf;th'e  7pace  h, 

described  may  be  said  to  push  them-  tween  the  maternal  and  foetal  portions  of  tlio 
Selves,  SO  as  to  dip-down  into  it,  carry-  villus;  e,  the  internal  membrane  of  the  villus, 
in*  before  them  a  portion  of  its  thin  continuous  with  the  external  membrane  of  the 
Wall,  which  constitutes  a  sheath  to  each  ^orionr/the  internal  cells  of  the  villus  bo- 

longing  to  the  chorion ;  a.  the  loop  of  unibih 
tutt.      JNow  as  every  extension   ot    the  cal  vessels. 
uterine  vessels  carries  the-  decidua  before 
it,  every  one  of  the  vascular  tufts  that  dips-down  into  it,  will  be  covered  with  ,\ 

'  Prof.  Goodsir's  "Anatomical  and  Pathological  Observations,"  p.  60. 

'"Edinb.   Med.  and  Surg.  Journ.  "  Jan.  1847;  and  "Aflat.  Physiol.,  and  Patbol    R» 
searches,"  Chap,  vm 
49 


i  ortion  of  one  of  the  Fcetal   Villi,  about  to 


.  215. 


770      OF   GENERATION:  —  ACTION   OF   THE   FEMALE. 

layer  of  the  cellular  structure  of  the  latter  ;  and  the  foetal  portion  of  each  tuft 
will  thus  be  inclosed  in  a  layer  of  maternal  cells  and  basement-membrane  (Fig. 
215,  a,  6,  c).  In  this  manner,  the  whole  interior  of  the  Placental  cavity  (Fig. 
216)  is  intersected  by  numerous  tufts  of  foetal  vessels  disposed  in  fringes,  and 
bound-down  by  reflexions  of  the  delicate  membrane  that  forms  its  proper  wall ; 
just  as  the  intestines  are  held  in  their  places  by  the  reflexions  of  the  peritoneum 
that  covers  them.  This  view  was  suggested  by  Dr.  Held  by  the  very  interesting 

FIG.  216. 


Section  of  a  portion  of  a  fully-formed  Placenta,  with  the  part  of  the  Uterus  to  which 
it  is  attached  : — a,  umbilical  cord ;  b,  b,  section  of  uterus,  showing  the  venous  sinuses  ; 
c,  c,  c,  branches  of  the  umbilical  vessels;  d,  d,  curling  arteries  of  the  uterus. 

fact,  that  the  tufts  of  foetal  vessels  not  unfrequently  extend  beyond  the  uterine 
surface  of  the   placenta,  and  dip-down  into  the  uterine   sinuses   (Fig-  217)  j 

FIG.  217. 


Diagram  of  the  structure  of  the  Placenta; — showing  a,  the  substance  of  the  uterus; 
b.  the  cavity  of  a  sinus  ;  c,  curling  arteries  ;  d,  d,  the  decidual  lining  of  the  uterus  ;  e,  e, 
the  foetal  tufts  dipping-down  into  this. 

where  they  are  still  covered,  and  held  in  their  places,  by  reflexions  of  the  sarao 
»nembrane.     All  the  bands  which  connect  and  tie-down  the  tufts,  are  formed  of 
the  same  elements  as  the  envelopes  of  the  tufts  themselves  ;  namely,  a  fold  of  the 
linine  membrane  of  the  decidual  sinuses,  and  a  layer  of  the  cellular  decidua. 
868.  The  Maternal  blood  is  conveyed  into  the  iPlacental  cavity  by  the  '  curling 


FORMATION  OF  THE  PLACENTA.  771 

arteries'  of  the  uterus  (Fig.  216,  d,  Fig.  217,  c) ;  and  is  received-back  from  it 
into  the  large  veins  that  are  commonly  designated  as  sinuses  (Figs.  216,  217, 
b  b~).  The  foetal  vessels  (Fig.  216,  c,  c,  Fig.  217,  e,  e)  being  bathed  in  this 
blood,  as  the  branchiae  of  aquatic  animals  are  in  the  water  that  surrounds  them, 
not  only  enable  the  foetal  blood  to  exchange  its  venous  character  for  the  arterial, 
by  parting  with  its  carbonic  acid  to  the  maternal  blood,  and  receiving  oxygen 
from  it;  but  they  also  serve  as  rootlets,  by  which  certain  nutritious  elements  of 
the  maternal  blood  (probably  those  composing  the  liquor  sanguinis)  are  taken 
into  the  system  of  the  foetus.  In  this,  they  closely  correspond  with  the  villi  of 
the  intestinal  canal ;  and  there  is  this  further  very  striking  analogy,  —  that  the 
nutrient  material  is  selected  and  prepared  by  two  sets  of  cells,  one  of  which  (the 
maternal)  transmits  it  to  the  other  (the  foetal),  in  the  same  manner  as  the  epithe- 
lial cells  of  the  intestinal  villi  seem  to  take-up  and  prepare  the  nutrient  matter, 
which  is  destined  to  be  still  further  assimilated  by  the  cells  that  float  in  the  cir- 
culating current  (§  121).  It  is  probable,  too,  that  the  Placenta  is  to  be  regarded 
as  an  excreting  organ ;  serving  for  the  removal,  through  the  maternal  blood,  of 
excrementitious  matter  whose  continued  circulation  through  the  blood  of  the 
foetus  would  be  prejudicial  to  the  latter.  And  it  will  be  in  this  mode,  that  the 
blood  of  the  mother  may  become  impregnated  with  substances,  or  impressed  with 
attributes,  originally  belonging  to  the  male  parent;  so  as  to  impart  these  to  the 
products  of  subsequent  conceptions  by  a  different  father  (§  881).  There  is  no 
more  direct  communication  between  the  mother  and  foetus,  than  that  which  is 
afforded  by  this  immersion  of  the  foetal  tufts  in  the  maternal  blood ;  all  the  ob- 
servations which  have  been  supposed  to  prove  the  existence  of  real  vascular  con- 
tinuity, having  been  falsified  by  the  extravasation  of  fluid,  probably  consequent 
upon  the  force  used  in  injecting  the  vessels.  Moreover,  the  different  size  of  the 
blood-corpuscles  in  the  foetus  and  in  the  parent  (§  167)  shows  the  non-existence 
of  any  such  communication. 

869.  The  formation  of  the  Placenta,  in  the  manner  just  described,  commences 
in  the  latter  part  of  the  second  month ;  during  the  third,  the  organ  acquires  its 
proper  character ;  and  it  subsequently  goes-on  increasing,  in  accordance  with  the 
growth  of  the  Ovum.  Towards  the  end  of  the  term  of  gestation,  however,  it 
becomes  more  dense  and  less  vascular;  owing,  it  would  seem,  to  the  obliteration 
of  several  of  the  minuter  vessels,  which  are  converted  into  hard  fibrous  filaments. 
The  vessels  of  the  Uterus  undergo  great  enlargement  throughout,  but  especially 
at  the  part  to  which  the  placenta  is  attached ;  and  the  blood  in  moving  through 
them  produces  a  peculiar  murmur,  which  is  usually  distinctly  audible  at  an  early 
period  of  pregnancy,  and  may  be  regarded  (when  due  care  is  taken  to  avoid 
sources  of  fallacy),  as  one  of  its  most  unequivocal  positive  signs.  The  'placental 
bruit'  is  thus  described  by  Dr.  Montgomery.1  "The  characters  of  this  pheno- 
menon are,  a  low  murmuring  or  somewhat  cooing  sound,  resembling  that  made 
by  blowing  gently  over  the  lip  of  a  wide-mouthed  vial,  and  accompanied  by  a 
slight  rushing  noise,  but  without  any  sensation  of  impulse.  The  sound  is,  in  its 
return,  exactly  synchronous  with  the  pulse  of  the  mother  at  the  time  of  exami- 
nation ;  and  varies  in  the  frequency  of  its  repetitions,  with  any  accidental  varia- 
tion which  may  occur  in  the  maternal  circulation.  Its  situation  does  not  vary 
during  the  course  of  the  same  pregnancy;  but  in  whatever  region  of  the  uterus 
it  is  first  heard,  it  will  in  future  be  found,  if  recognized  at  all, — for  it  is  liable  to 
intermissions, — at  least,  we  shall  occasionally  be  unable  to  hear  it  where  we  have 
already  heard  it  a  short  time  before,  and  where  we  shall  shortly  again  recognize 
it.  According  to  my  experience,  it  will  be  most  frequently  heard  about  the 
situation  of  the  Fallopian  tube  of  the  right  side ;  but  it  may  be  detected  in  any 
of  the  lateral  or  anterior  parts  of  the  uterus."  That  the  cause  of  this  sound 
exists  in  the  Uterus  itself,  is  distinctly  proved  by  the  fact,  that  it  has  been  heard 
when  that  organ  was  so  completely  anteverted,  that  the  fundus  hung-down 
1  "Signs  of  Pregnancy,"  p,  121. 


772          OF    GENERATION:  —  ACTION    OF    THE    FEMALE. 

between  the  patient's  thighs.  A  sound  so  much  resembling  this  as  to  be  scarcely 
distinguishable  from  it,  may  be  occasioned,  however,  by  a  cause  of  a  very  differ- 
ent nature, — namely,  an  abdominal  tumour,  pressing  upon  the  aorta,  iliac  arteries, 
or  enlarged  vessels  of  its  own;  and,  in  doubtful  cases,  it  is  necessary  to  give  full 
weight  to  the  possibility  of  such  an  explanation.  The  sound  may  be  imitated  at 
any  time,  by  pressing  the  stethoscope  on  the  iliac  arteries.  The  placental  bruit 
has  been  not  unfrequently  heard  in  the  llth  week;  but  it  cannot  generally  be 
detected  before  the  fourth  month,  when  the  fundus  uteri  rises  above  the  anterior 
wall  of  the  pelvis. 

870.  The  increase  in  the  size  of  the  Uterus,  which  takes-place  pari  passu 
with  the  enlargement  of  the  ovum,  is  accompanied  with  a  remarkable  augmenta- 
tion in  the  amount  of  its  substance.  Up  to  about  the  fifth  or  sixth  month,  not 
only  its  cavity,  but  the  thickness  of  its  walls,  is  progressively  added-to;  from 
that  time  to  the  end  of  gestation,  the  thickness  of  the  walls  diminishes  whilst 
the  cavity  increases,  but  not  in  an  equal  proportion ;  and  at  the  conclusion  of 
parturition,  its  solid  bulk  is  estimated  at  about  twenty-four  times  that  of  the  un- 
impregnated  Uterus.  The  augmented  volume  of  the  organ  is  chiefly  due  to  the 
increased  development  of  its  Muscular  coat,  which  is  composed  of  the  fusiform 
cells  with  staff-shaped  nuclei,  that  make-up  the  'non-striated'  muscular  fibre  else- 
where. According  to  Prof.  Kolliker,  a  vast  amount  of  new  fibres  are  generated 
during  the  early  months  of  pregnancy;  but  there  is  at  the  same  time  an  extraor- 
dinary increase  in  the  size  of  those  previously  formed,  their  length  being  multi- 
plied from  seven  to  eleven  times,  and  their  width  from  twice  to  five  times.  After 
the  sixth  month,  the  origination  of  new  muscular  fibres  seems  to  cease,  but  the 
augmentation  in  the  size  of  those  already  generated  seems  to  continue.  The  con- 
nective tissue  which  unites  the  muscular  fibres,  also  increases  during  pregnancy, 
and  becomes  more  distinctly  fibrous.1  It  has  been  affirmed  that  the  Nervous  sub- 
stance of  the  Uterus  also  undergoes  a  great  augmentation  during  pregnancy ;  but 
of  this  no  sufficient  evidence  has  yet  been  adduced.  • —  Simultaneously  with  the 
enlargement  of  the  uterus,  the  Mammary  Gland  and  its  appendages  undergo  a 
fuller  development ;  and  from  this  a  valuable,  but  not  unequivocal,  indication  of 
pregnancy  may  be  drawn.  Occasional  shooting  pains  in  the  Mammae  are  not 
unfrequently  experienced  within  a  short  period  after  conception ;  and  more  con- 
tinued tenderness  is  also  not  unusual.  A  sense  of  distension  is  very  commonly 
experienced  at  about  the  end  of  the  second  month ;  and  from  that  time  a  distinct 
1  knottiness '  usually  begins  to  present  itself,  increasing  with  the  advance  of  preg- 
nancy. In  many  instances,  however,  these  mammary  sympathies  are  entirely 
absent ;  and  they  may  be  simulated  by  changes  that  take  place  in  consequence 
of  various  affections  of  the  uterus.  A  change  of  colour  in  the  areola  is  a  very 
common,  but  not  an  invariable,  occurrence  in  the  early  months  of  pregnancy; 
but  another  sign  is  afforded  by  the  areola  and  nipple,  which  is  of  more  value 
because  more  constant,  —  namely,  a  puffy  turgescence,  and  an  increased  develop- 
ment of  the  little  glandular  follicles,  or  tubercles,  which  commonly  secrete  a 
dewy  moisture. — Many  other  changes  in  the  constitution  occur  during  pregnancy ; 
indicated  by  the  buffiness  of  the  blood,  the  irritability  of  the  stomach,  and  the 
increased  excitability  of  the  mind.  All  these,  however,  are  discussed  with  suffi- 
cient amplification,  in  works  on  Obstetric  Medicine. 

871.  The  act  of  Conception,  being  one  of  a  purely  organic  nature,  is  not  itself 
productive  of  any  sensation  on  the  part  of  the  mother;  but  there  are  some  wo- 
men in  whom  it  is  attended  with  certain  sympathetic  affections,  such  as  faintness, 
vertigo,  &c.,  that  enable  them  to  fix  upon  the  particular  time  at  which  it  has 
taken  place.  From  that  period,  however,  the  mother  has  no  direct  consciousness 
of  the  change  going-on  in  the  uterus  (save  by  the  effects  of  its  increasing  pres- 
sure on  other  parts),  until  the  occurrence  of  what  is  termed  t  quickening/  This 
is  generally  described  as  a  kind  of  fluttering  movement,  attended  with  some  de- 

1  See  Kolliker's  "Manual  of  Human  Histology"  (Syd.  SOC.'B  Ed.),  vol.  ii.,  p  258,  259. 


SIGNS    OF    PREGNANCY.  —  QUICKENING.  773 

gree  of  syncope  or  vertigo.  After  it  has  once  occurred,  and  has  strongly  excited 
attention,  it  is  occasionally  renewed  once  or  twice,  and  then  gives-place  to  the 
ordinary  movements  of  the  foetus.  Not  unfrequently,  however,  no  movement 
whatever  is  felt,  until  near  the  end  of  the  term  of  gestation,  or  even  through  the 
whole  of  it.  As  to  the  cause  of  the  sensation,  Obstetricians  are  much  divided; 
and  no  satisfactory  account  has  been  given  of  it.  It  has  been  vulgarly  supposed 
to  be  due  to  the  first  movement  of  the  fostus,  which  was  imagined  then  to  be- 
come possessed  of  an  independent  life ;  and  the  English  law  recognizes  the  truth 
of  this  doctrine,  in  varying  the  punishment  of  an  attempt  to  procure  Abortion, 
according  to  whether  the  woman  be  'quick  with  child'  or  not;  and  in  delaying 
execution  when  a  woman  can  be  proved  to  be  so,  though  it  is  made  to  proceed 
if  she  is  not,  even  if  she  be  unquestionably  pregnant.  Whether  or  not  the  first 
sensible  motions  of  the  fostus  are  the  cause  of  the  peculiar  feeling  in  question, 
there  can  be  no  doubt  that  the  embryo  has  as  much  independent  vitality  before, 
as  after,  the  quickening.  From  the  time  that  the  ovum  quits  the  ovary,  it  ceases 
to  be  a  part  of  the  parent,  and  is  dependent  on  it  only  for  a  due  supply  of  nour- 
ishment, which  it  converts,  by  its  own  inherent  powers,  into  its  proper  fabric. 
But  this  dependence  cannot  be  said  to  cease  at  the  moment  of  quickening;  for 
the  connection  must  be  prolonged  during  several  weeks,  before  the  fostus  becomes 
capable  of  sustaining  life  without  such  assistance.  The  earliest  period  at  which 
this  may  occur,  will  be  presently  considered  (§  876). 

872.  At  the  conclusion  of  about  forty  weeks,  or  (less  correctly)  nine  solar 
months,1  from  the  period  of  conception,  the  time  of  Parturition  arrives.  In  this 
act,  the  muscular  walls  of  the  Uterus  are  primarily  concerned;  for  a  kind  of 
peristaltic  contraction  takes-place  in  them,  the  tendency  of  which  is  to  press  the 
contents  of  the  cavity  from  the  fundus  towards  the  os  uteri,  and  finally  to  expel 
them ;  and  this  contraction  is  alone  sufficient  to  empty  the  uterus,  when  no  im- 
pediment is  presented  to  the  exit  of  the  foetus,  as  we  see  in  the  occasional  occur- 
rence of  post-mortem  parturition.  It  is,  in  fact,  in  the  contraction  of  the  fibres 
of  the  fundus  and  body  of  the  uterus,  and  in  a  relaxation  of  those  about  the  cervix 
(which  relaxation  is  something  quite  different  from  a  mere  yielding  to  pressure, 
and  is  obviously  a  vital  phenomenon  that  marks  a  peculiarity  in  the  actions  of  this 
part),  that  the  first  stage  of  an  ordinary  labour  essentially  consists.  There  is  no 
proof  whatever,  that  these  changes  are  dependent  upon  nervous  influence ;  in 
fact,  there  is  much  evidence  that  the  parturient  action  of  the  uterus  is  not  the 
result  (as  some  have  maintained  it  to  be)  of  a  '  reflex '  action  of  the  Spinal  Cord, 
but  is  due  to  its  inherent  contractility  ;  for  numerous  instances  have  occurred,  in 
which  normal  parturition  has  taken-place,  notwithstanding  the  destruction  of  the 
lower  part  of  the  Cord,  or  the  existence  of  a  state  of  complete  paraplegia  which 
marked  its  functional  inactivity ;  and  the  continuance  of  the  peristaltic  action 
for  some  time  after  somatic  death,  when  neither  the  Cerebro-spinal  nor  the  Sym- 
pathetic system  can  afford  any  supply  of  nervous  power,  is  a  yet  more  satisfactory 
proof  of  the  same  position. — Nevertheless,  it  seems  quite  certain  that  muscular 
contractions  of  the  Uterus  may  be  induced  by  reflex  action ;  for  in  no  other  way 
can  we  account  for  numerous  phenomena,  which  distinctly  mark  the  operation 
of  remote  causes  acting  through  the  nervous  system ;  such  as  the  induction  of 

1  Although  'nine  months'  is  usually  spoken-of  as  the  term  of  Gestation,  yet  the  real 
term  of  forty  weeks  exceeds  this  by  from  five  to  seven  days,  according  to  the  months 
included.  The  mode  of  reckoning  customary  among  women,  is  to  date  from  the  middle  of 
the  month  after  the  last  appearance  of  the  Catamenia  ;  but  it  is  certain  that  Conception  is 
much  more  likely  to  take  place  soon  after  they  have  ceased  to  flow,  or  even  just  before 
their  access,  than  in  the  intervening  period  (g  853) ;  so  that,  in  most  instances,  it  would 
be  most  correct  to  expect  labour  at  forty  weeks  and  a  few  days  after  the  last  recurrence 
of  the  Menses. — The  period  of  quickening  may  be  relied-on  in  some  women,  in  whom  it 
occurs  with  great  regularity  in  a  certain  week  of  pregnancy ;  but  in  general  there  is  great 
latitude  as  to  the  time  of  its  occurrence.  The  usual  or  average  time  seems  to  be  about 
the  18th  week  of  gestation. 


774      OF  GENERATION:  —  ACTION   OF  THE  FEMALE. 

uterine  contractions  by  the  dash  of  cold  water  on  the  abdominal  surface,  by  the 
injection  of  cold  water  into  the  vagina,  by  the  ingestion  of  cold  water  into  the 
stomach,  or  even  by  dipping  the  hands  into  cold  water,  or  again  by  the  suctorial 
application  of  the  infant's  lips  to  the  nipple,  by  the  introduction  of  the  hand  into 
the  vagina,  by  violent  movements  of  other  parts  of  the  body,  and  by  various 
other  means.  This  general  fact  has  an  important  practical  bearing;  since  there 
are  various  occasions  on  which  it  is  most  important  to  life,  that  the  previously- 
flaccid  uterus  should  be  excited  to  vigorous  contraction,  for  the  sake  of  accelera- 
ting parturition  or  of  suppressing  haemorrhage ;  whilst,  on  the  other  hand,  it  is 
often  no  less  important  to  be  able  to  prevent  or  to  antagonize  the  operation  of 
cause-s  which  would  prematurely  induce  uterine  contractions,  to  the  destruction 
of  the  offspring  and  the  danger  of  the  mother. 

873.  When,  in  the  normal  act  of  Parturition,  the  head  has  so  far  made  its  way 
through  the  os  uteri  as  to  begin  to  distend  the  lower  part  of  the  genital  canal,  a 
new  kind  of  expulsive  effort  is  superadded  to  that  of  the  Uterus  itself;  the  assist- 
ance of  the  Expiratory  muscles  being  then  called  in  (§  511),  through  the  inter- 
mediation of  the  Spinal  Cord,  which  is  probably  excited  to  this  action  by  the  sti- 
mulus thus  applied  to  the  afferent  nerves  of  the  compressed  parts ;  and  it  is  chiefly 
by  the  instrumentality  of  these  muscles,  that  the  normal  act  of  parturition  is  usu- 
ally completed.     The  same  action  which  expels  the  foetus,  generally  also  detaches 
the  placenta ;  and  if  the  uterus  contract  with  sufficient  force  after  this  has  been 
thrown-off,  the  orifices  of  the  vessels  which  communicate  with  it  are  so  effectually 
closed,  that  little  or  no  haemorrhage  takes  place.     If,  however,  the  uterus  does 
not  contract,  or  relaxes  after  having  contracted,  a  large  amount  of  blood  may  be 
lost  in  a  short  time  from  the  open  orifices.     For  some  little  time  after  parturition, 
a  sero-sanguineous  discharge,  termed  the  lochia,  is  poured-out  from  the  uterus ; 
and  this  commonly  contains  shreds  of  the  deciduous  membrane,  which  had  not 
been  previously  detached,  together  with  a  quantity  of  fat-globules,  and  other  pro- 
ducts of  disintegration  of  the  uterine  tissue  (§  349). '     Within  a  few  weeks  after 
delivery,  the  uterus  regains  (at  least  in  a  healthy  subject)  its  previous  condition ; 
part  of  its  newly-generated  muscular  fibres  seem  to  disappear  altogether,  whilst 
the  others  shrink  to  their  ordinary  dimensions;  and  the  portion  of  its  mucous 
membrane  which  had  been  thrown  off  as  Decidua,  seems  to  be  reproduced  in  the 
course  of  the  second  or  third  month. 

874.  As  to  the  reason  why  the  period  of  Parturition  should  be  just  forty  weeks 
after  the  occurrence  of  Conception,  we  know  nothing  more  than  we  do  of  that  of 
similar  periodical  phenomena  in  the  history  of  the  life  of  Man  and  of  other  living 
beings;  all  of  which  must  be  considered  as  occasional  manifestations  of  changes 
that  are  constantly  in  progress,  whose  rate,  being  dependent  upon  the  degree  of 
Heat  supplied,  is.  so  uniform  in  warm-blooded  animals,  as  to  secure  a  very  close 
conformity  to  a  common  standard.2     There  is  evidence  that  the  occurrence  of  the 
uterine  nisus  may  be  induced  by  a  variety  of  causes,  several  of  which  probably 
concur  in  the  normal  act  of  Parturition.     For,  in  the  first  place,  the  state  of  de- 

1  In  addition  to  the  evidence  above  referred-to,  of  the  rapid  occurrence  of  fatty  degene- 
ration of  the  uterine  structure  after  parturition,  the  Author  may  mention  that  he  has  been 
informed  by  Dr.  Retzius  (Professor  of  Midwifery  at  Stockholm)  that  he  has  detected  a 
large  number  of  fat-globules  in  the  urine  of  puerperal  women.  Is  it  not  possible — it  may 
be  further  asked — that  some  of  the  oleaginous  matter  so  copiously  poured-forth  by  the 
Mammary  glands,  may  be  derived  from  this  source  ?  Such  an  economy  of  nutrient  mate- 
rial would  be  consistent  with  what  we  elsewhere  meet-with ;  and  the  idea  is  conformable 
to  the  fact,  that  the  proportion  of  butyrine  in  the  milk  is  much  greater  in  the  earlier,  than 
in  the  later  months  of  lactation  ($  923). 

*  This  may  be  best  illustrated  by  the  analogy  of  a  Leyden  jar  which  is  being  charged  by 
the  continuous  action  of  an  Electrical  Machine,  and  Vhich  is  so  arranged  as  to  discharge 
itself  spontaneously  whenever  the  disturbance  in  its  equilibrium  attains  a  certain  intensity. 
ll  the  movement  of  the  machine  be  uniform,  and  other  conditions  remain  the  same,  the  dis- 
charge will  take  place  at  regular  intervals. 


PREMATURE    EXPULSION    01     THE    FCETUS  77-r> 

velopment  of  the  muscular  substance  of  the  Uterus  can  scarcely  be  without  a  con- 
siderable influence  on  this  operation.  We  see  it  undergoing  a  gradual  augmen- 
tation during  the  period  of  pregnancy,  without  any  demand  being  made  upon  its 
functional  activity ;  it  gradually  becomes  more  and  more  irritable,  contractions 
being  far  more  readily  excited  in  it  by  electrical  or  other  stimulation,  in  the  later 
than  in  the  earlier  months  of  pregnancy;  and  at  last  this  irritability  seems  to 
reach  its  acme,  in  virtue  of  the  nutritive  changes  which  have  been  progressively 
taking  place  in  it,  and  to  discharge  itself  in  one  powerful  effort  (See  §  242). 
Certain  preparatory  changes  are  known  to  be  taking-place  in  the  Uterus  itself, 
during  the  last  two  or  three  weeks  of  gestation;  for  its  upper  part  contracts  more 
closely  around  its  contents,  as  if  it  were  bracing  itself  up  for  the  coming  encoun- 
ter; whilst  there  is  a  greater  disposition  to  relaxation  of  its  lower  part,  as  also  in 
the  soft  parts  surrounding  the  orifice  of  the  pelvis,  so  that  the  whole  mass  de- 
scends. It  is  well  known  that  there  is  far  less  aptitude  for  dilatation  in  the  os 
uteri,  before  this  change  has  taken  place ;  so  that  premature  labours  are  frequently 
rendered  very  difficult  and  tedious  by  the  resistance  which  the  feet  us  encounters 
from  the  soft  parts,  notwithstanding  that  its  smaller  size  enables  it  io  pass  more 
readily  through  the  pelvic  canal. — That  the  parturient  effort,  however,  is  not 
solely  dependent  upon  the  state  of  development  of  the  uterus,  appears  from  seve- 
ral considerations  :  and,  in  the  first  place,  from  the  very  curious  fact  that,  in  cases 
of  extra-uterine  foetation,  contractions  resembling  those  of  labour  take  place  in  its 
walls.  In  fact,  what  may  be  termed  the  maturation  not  merely  of  the  Uterus, 
but  also  of  its  Embryonic  contents, — a  condition  analogous  to  that  which  precedes 
the  dropping  of  ripe  fruit,  and  which  is  acquired  by  the  completion  of  the  deve- 
lopmental process, — appears  to  have  more  influence  in  determining  the  normal 
parturient  effort,  than  any  other  cause  which  can  be  assigned.  The  Placenta  of 
the  fully-developed  foetus,  indeed,  is  somewhat  in  the  condition  of  the  footstalk 
of  a  ripening  fruit ;  that  is,  having  attained  its  full  evolution  as  an  organ  of  tem- 
porary function,  its  connection  tends  to  become  dissevered  in  virtue  of  the  further 
changes  which  take  place  in  itself,  quite  irrespectively  of  any  external  agency.1 
This  is  very  strikingly  evinced  by  the  fact,  that  when  the  uterus  contains  two 
foetuses,  and  one  of  them  is  expelled, — either  in  consequence  of  impeded  deve- 
lopment or  of  disease  in  itself,  or  because  it  has  attained  its  own  full  term  of  de- 
velopment (as  in  cases  of  superfcetation,  §  878), — the  other,  if  its  development  at 
this  period  is  far  from  complete,  is  often  retained,  and  goes-on  to  its  full  term,  its 
placenta  not  being  detached  in  the  first  parturient  effort,  because  it  was  not  then 
prepared  for  the  separation.  It  is  obvious  that  this  view  affords  a  rational  expla- 
nation of  the  occurrence  of  uterine  action  in  cases  of  extra-uterine  foetation ;  for, 
if  the  condition  of  the  placental  attachment  furnish  its  exciting  cause,  it  will  do 
so  equally,  whether  the  placenta  be  attached  to  the  lining  of  the  uterus,  or  to  that 
of  the  Fallopian  tube,  or  to  any  other  organ.  It  is  an  additional  indication  that 
the  immediate  stimulus  to  the  parturient  effort  of  the  uterus,  is  given  by  some 
change  in  the  condition  of  its  foetal  connections,  that  the  term  of  gestation  seems 
capable  of  being  prolonged  by  peculiarities  in  the  constitution  or  rate  of  develop- 
ment of  the  foetus,  which  are  derived  from  the  male  parent;  for  it  was  ascertained 
by  the  late  Earl  Spencer,2  that  of  75  cows  in  calf  by  a  particular  bull,  the  ave- 
rage period  was  288 \  days,  instead  of  280;  none  of  these  having  gone  less  than 
281  days,  and  two-fifths  of  them  having  exceeded  289  days.3 

1  Such  a  change  may  be  easily  verified  in  the  placenta  of  many  of  the  lower  animals, 
such  as  the  Cat,  in  which  the  foetal  and  maternal  portions  remain  more  distinct  from  each 
other,  than  they  do  in  the  Human  female ;  for  these  become  far  more  easily  separable  as 
the  period  of  parturition  draws  near,  than  they  are  at  any  previous  time. 

9  See  Dr.  J.  C.  Hall  in  "  Medical  Gazette,"  May  6,  1842. 

3  The  very  ingenious  doctrine  has  been  propounded  by  Dr.  Tyler  Smith  ("Parturition, 
and  the  Principles  and  Practice  of  Obstetrics,"  Amer.  Edit.)*  that  the  exciting  cause  of 
parturition  is  to  be  found  in  the  recurrence  of  the  periodical  excitement  of  the  ovary,  act. 


776     OF  GENERATION:  —  ACTION   OF  THE  FEMALE. 

875.  Various  states  of  the  constitution,  especially  that  which  is  designated  as- 
1  irritability/  may  induce  the  occurrence  of  the  parturient  effort  at  an   earlier 
period;  and  this  constitutes  Premature  Delivery,  or  Abortion,  according  as  the 
child  is,  or  is  not,  viable  (§  876).     There  are  some  women  in  whom  this  regularly 
happens  at  a  certain  month,  so  that  it  seems  to  be  an  action  natural  to  them ;  but 
it  is  always  to  be  prevented,  if  possible,  being  injurious  alike  to  the  mother  and 
to  the  child ;  and  this  prevention  is  to  be  attempted  by  rest  and  tranquillity  of 
mind  and  body,  and  by  a  careful  avoidance  of  all  the  exciting  causes  which  may 
produce  uterine  contractions  by  their  operation  on  the  Nervous  system  (§  872). 
Among  the  causes  of  Abortion,  however,  the  death  of  the  footus,  or  an  abnormal 
state  of  the  placental  structure,  is  one  of  the  most  common ;  and  thus  we  have 
another  very  distinct  proof  of  the  influence  which  the  state  of  the  contents  of  the 
uterus  has  on  the  induction  of  the  parturient  effort. 

876.  The  question  of  the  extreme  limits  of  the  period  of  Gestation,  is  one  of 
great  importance  both  to  the  Practitioner  and  to  the  Medical  Jurist. — In  regard 
to  the  shortest  period  at  which  Gestation   may  terminate,  consistently  with  the 
viability  of  the  Child,  there  is  still  a  great  degree  of  uncertainty.     Most  practi- 
tioners are  of  opinion,  that  it  is  next  to  impossible  for  a  foetus  to  live  and  grow 
to  maturity,  which  has  not  nearly  completed  its  seventh  month  j  but  it  is  un- 
questionable  that  infants  born  at  a  much  earlier  period,  have  lived  for  some 
months,  or  even  to  adult  age.     It  is  rare  in  such  cases,  however,  that  the  date  of 
conception  can  be  fixed  with  sufficient  precision  to  enable  a  definite  statement  to 
be  given.     Of  the  importance   of  the  question,  a  case  which  some  time  since 
Occurred  in  Scotland  affords  sufficient   proof.     A  vast  amount  of  contradictory 
evidence  was  adduced  on  this  trial ;  but,  on  the  general  rule  of  accepting  positive 
in  preference  to  negative  testimony,  it  seems  that  we  ought  to  consider  it  possible 
that  a  child  may  live  for  some  months,  which  has  been  born  at  the  conclusion  of 
24  weeks  of  gestation.     In  the  case  in  question,  the  Presbytery  decided  in  favour 
of  the  legitimacy  of  an  infant  born  alive  within  25  weeks  after  marriage.1     A 
very  interesting  case  is  on  record,2  in  which  the  mother  (who  had  borne  five  chil 
dren)  was  confident  that  her  period  of  gestation  was  less  than  19  weeks;  the 
facts  stated  respecting  the  development  of  the  child  are  necessarily  very  imper- 
fect, as  it  was  important  to  avoid  exposing  his  body,  in  order  that  his  temperature 
might  be  kept-up ;  but  three  weeks  after  his  birth,  he  was  only  13  inches  in 
length,  and  his  weight  was  no  more  than  29  oz.     At  that  time,  according  to  the 
calculation  of  the  mother,  he  might  be  regarded  as  corresponding  with  an  infant 
of  22  weeks  or  5  months ;  but  the  length  and  weight  were  greater  than  is  usual 
at  that  period,  and  he  must  probably  have  been  born  at  about  the  25th  week.    It 

ing  by  reflexion  on  the  uterus  through  the  spinal  system  of  nerves,  the  ovarian  nerves 
being  the  excitors,  and  the  uterine  the  motors ;  this  excitement  continuing  during  the  en- 
tire period  of  gestation,  and  giving  a  special  tendency  to  abortion  at  each  return ;  and 
acting  with  such  potency  at  the  eleventh  recurrence,  as  then  to  induce  the  parturient 
effort.  He  assigns  no  other  cause,  however,  why  this  eleventh  recurrence  should  be  so 
much  more  effectual  than  the  rest,  than  that  by  this  time  there  is  a  much  greater  aptitude 
to  contraction  in  the  uterus  itself,  and  an  increased  readiness  to  be  thrown-off  on  the  part 
of  the  placenta, — conditions  which  seem  to  the  Author  to  be  in  themselves  adequate  to 
account  for  the  result.  Dr.  Tyler  Smith's  hypothesis  is  distinctly  negatived  by  the  follow- 
ing facts : — 1.  The  period  of  gestation,  although  commonly  a  multiple  of  the  menstrual  in- 
terval, is  by  no  means  constantly  so ;  the  former  often  remaining  normal,  when  the  latter 
is  shorter  or  longer  than  usual.  2.  Parturient  efforts  take-place  in  the  uterus,  notwith- 
standing the  previous  removal  of  the  lower  part  of  the  spinal  cord.  3.  The  removal  of  the 
ovaries  in  the  later  part  of  gestation  does  not  interpose  the  least  check  to  the  parturient 
action,  as  Prof.  Simpson  of  Edinburgh  has  experimentally  ascertained. — The  Autho*  con- 
siders himself  fully  justified,  therefore,  in  asserting  that  this  hypothesis  does  not  possess 
the  slightest  claim  to  be  entertained  as  even  a  possible  one ;  and  would  refer,  for  a  more 
letailed  examination  of  it,  to  the  "  Brit,  and  For.  Med.-Chir.  Review,"  vol.  iv.  p.  1. 
1  "Report  of  Proceedings  against  the  Rev.  Fergus  Jardine,"  Edinburgh,  1839, 
"  Edinb.  Med.  and  Surg.  Journal,"  vol.  xi. 


PROTRACTED     GESTATION.  777 

is  an  interesting  feature  in  this  case,  that  the  calorific  power  of  the  infant  was  so 
low,  that  artificial  heat  was  constantly  needed  to  sustain  it;  but  that  under  the 
influence  of  heat  of  the  fire  he  evidently  became  weaker,  whilst  the  warmth  of  a 
person  in  bed  rendered  him  lively  and  comparatively  strong.  During  the  first 
week,  it  was  extremely  difficult  to  get  him  to  swallow;  and  it  was  nearly  a  month 
before  he  could  suck.  At  the  time  of  the  report,  he  was  four  months  old,  and  his 
health  appeared  very  good. — Another  case  of  very  early  viability  has  been  more 
recently  put  on  record  by  Mr.  Dodd  :a  in  this,  as  in  the  former  instance,  the  de- 
termination of  the  chilu's  age  rests  chiefly  on  the  opinion  of  the  mother;  but 
there  appears  no  reason  for  suspecting  any  fallacy.  The  child  seems  to  have  been 
born  at  the  26th  or  27th  week  of  gestation  :  and  having  been  placed  under  judi- 
cious management,  it  has  thriven  well. — One  of  the  most  satisfactory  cases  on 
record,  is  that  detailed  by  Dr.  Oatrepont2  (Professor  of  Obstetrics  at  Wurtz- 
burgh),  and  stated  by  Dr.  Christison  in  his  evidence  on  the  case  first  alluded-to. 
The  evidence  is  as  complete  as  it  is  possible  to  be  in  any  case  of  the  kind ;  being 
derived  not  only  from  the  date  assigned  by  the  mother  to  her  conception,  but 
also  from  the  structure  and  history  of  the  child.  The  gestation  could  have  only 
lasted  27  weeks,  and  was  very  probably  less.  The  length  of  the  child  was  13  £ 
inches,  and  its  weight  was  24  oz.  Its  development  was  altogether  slow  ;  and  at 
the  age  of  eleven  years,  the  child  seemed  no  more  advanced  in  body  or  mind, 
than  most  other  lads  of  seven  years  old.  In  this  last  point,  there  is  a  very  strik- 
ing correspondence  with  the  results  of  other  observations  upon  premature  chil- 
dren, made  at  an  earlier  age. — A  very  remarkable  case  has  been  since  put  on 
record  by  Dr.  Barker  of  Dumfries,3  in  which  the  child  is  affirmed  to  have  been 
born  on  the  158th  day  of  gestation,  or  in  the  middle  of  the  twenty-third  week 
after  intercourse.  Its  size,  weight,  and  grade  of  development  were  conformable 
to  the  asserted  period:  for  it  weighed  only  16  oz.,  and  measured  11  inches;  it 
had  only  rudimentery  nails,  and  scarcely  any  hair  except  a  little  of  reddish  colour 
on  the  back  of  the  head ;  the  eyelids  were  closed,  and  did  not  open  until  the 
second  day ;  the  skin  was  shrivelled.  When  born  it  was  wrapped-up  in  a  box 
and  placed  before  the  fire.  The  child  did  not  suck  properly  until  after  the  lapse 
of  a  month,  and  did  not  walk  until  she  was  nineteen  mouths  old.  Three  years 
and  a  half  afterwards,  this  child  was  in  a  thriving  state*,  and  very  healthy,  but 
of  small  make;  she  then  weighed  29  i  Ibs. 

877.  A  like  uncertainty  exists  with  regard  to  the  degree  of  protraction  of 
which  the  ordinary  duration  of  Gestation  is  capable. — Many  obstetric  practitioners, 
whose  experience  should  give  much  weight  to  their  opinion,  maintain  that  the 
regular  period  of  40  weeks  is  never  extended  by  more  than  two  or  three  days; 
whilst,  on  the  other  hand,  there  are  numerous  cases  on  record,  which,  if  testi- 
mony is  to  be  believed  at  all  (and  in  many  of  these,  the  character  and  circum- 
stances of  the  parties  place  them  above  suspicion),  furnish  ample  evidence,  that 
Gestation  may  be  prolonged  for  at  least  three  weeks  beyond  the  regular  term.4 
The  English  law  fixes  no  precise  limit;  and  the  decisions  which  have  been  given 
in  our  courts,  when  questions  of  this  kind  have  been  raised,  have  been  mostly 
formed  upon  the  collateral  circumstances.  The  1-aw  of  France  provides  that  the 
legitimacy  of  a  child  born  within  300  days  after  the  death  or  departure  of  the 
husband  shall  not  be  questioned;  and  a  child  born  after  more  than  300  days  is 
not  declared  a  bastard,  but  its  legitimacy  may  be  contested.  By  the  Scotch  law, 
a  child  is  not  declared  a  bastard,  unless  born  after  the  tenth  month  from  the 
death  or  departure  of  the  husband. — Very  important  evidence  on  this  subject  is 
afforded  by  investigations  on  the  lower  animals,  which  are  free  from  many  sources 

1  "  Provincial  Medical  and  Surgical,''  vol.  ii.  p.  474. 
3  "  Henke's  Zeitschrift,"  band  vi. 
8  "  Medical  Times,"  Sept.  7,  and  Oct.  12,  1850. 

*  A  good  collection  of  such  cases  will  be  found  in  Dr.  Montgomery's  excellent  work  ou 
the  "Signs  of  Pregnancy,"  and  in  Dr.  A.  Taylor's  "Medical  Jurisprudence."  Am.  Edit. 


778      OF  GENERATION:  —  ACTION   or  THE  FEMALE. 

of  fallacy  that  attend  human  testimony.  The  observations  of  Tessier,  which 
were  continued  during  a  period  of  forty  years,  with  every  precaution  against  in 
accuracy,  have  furnished  a  body  of  results  which  seems  quite  decisive.  In  the 
Cow,  the  ordinary  period  of  gestation  is  about  the  same  as  in  the  Human  female ; 
but  out  of  577  individuals,  no  less  than  20  calved  beyond  the  298th  day,  and  of 
these,  some  went-on  to  the  321st,  making  an  excess  of  nearly  six  weeks,  or  about 
one-seventh  of  the  entire  period.  Of  447  Mares,  whose  natural  period  of  gesta- 
tion is  about  335  days,  42  foaled  between  the  359th  and  the  419th  days,  the 
greatest  protraction  being  thus  84  days,  or  just  one-fourth  of  the  usual  term. 
Of  912  Sheep,  whose  natural  period  is  about  151  days,  96  yeaned  beyond  the 
153d  day;  and  of  these,  7  went-on  until  the  157th  day,  making  an  excess  of  6 
days.  Of  161  Eabbits,  whose  natural  period  is  about  30  days,  no  fewer  than  25 
littered  between  the  32d  and  the  35th ;  the  greatest  protraction  was  here  one- 
sixth  of  the  whole  period,  and  the  proportion  in  which  there  was  a  manifest  pro- 
longation was  also  nearly  one-sixth  of  the  total  number  of  individuals.  In  the 
incubation  of  the  common  Hen,  the  duration  of  which  must  be  entirely  deter- 
mined by  the  rate  of  embryonic  development,  Tessier  found  that  there  was  not 
unfrequently  a  prolongation  to  the  amount  of  three  days,  or  one-seventh  of  the 
whole  period.  —  In  regard  to  Cows,  the  observations  of  Tessier  have  been  con- 
firmed by  those  of  Earl  Spencer,  who  has  published '  a  table  of  the  period  of 
gestation  as  observed  in  764  individuals ;  he  considers  the  average  period  to  be 
284  or  285  days;  but  no  fewer  than  310  calved  after  the  285th  day;  and  of 
these,  3  went-on  to  the  306th  day,  and  1  to  the  313th.  It  is  curious  that 
among  the  calves  born  between  the  290th  and  300th  days,  there  was  a  decided 
preponderance  of  males,  —  these  being  being  74,  to  32  females ;  whilst  all  of 
those  born  after  the  300th  day  were  females.  The  additional  series  of  observa- 
tions subsequently  made  by  Earl  Spencer,  in  regard  to  the  constant  protraction 
of  the  period  in  75  cows  in  calf  by  a  particular  bull,  has  been  already  noticed 
(§  874). — Anotherseries  of  observations  has  been  published  by  Mr.  C.  N.  Bement 
of  Albany,  U.  S.,2  who  has  recorded  the  period  of  gestation  of  62  Cows.  The 
longest  period  was  336  days ;  the  shortest,  213  days.  The  average  period  for 
male  calves  was  288  days ;  and  for  females  282  days.  —  On  the  whole  it  may  be 
considered,  that  in  regard  to  the  Human  female,  the  French  law  is  a  very  reason- 
able one }  there  being  quite  sufficient  analogical  evidence  to  support  the  assertions 
of  females  of  good  character,  having  no  motive  to  deceive,  which  lead  to  the  con- 
clusion that  a  protraction  of  at  least  four  weeks  is  quite  possible,  and  that  a  pro- 
traction of  six  weeks  is  scarcely  to  be  denied.3 

878.  There  is  another  question  regarding  the  function  of  the  Female  in  the 
Reproductive  act,  which  is  of  great  interest  in  a  scientific  point  of  view,  and 
which  may  become  of  importance  in  Juridical  inquiries ;  namely,  the  possibility 
of  Superfoetation ;  that  is,  of  two  distinct  conceptions  at  an  interval  of  greater 
or  less  duration  j  so  that  two  foetuses  of  different  ages,  the  offspring  perhaps  of 
different  parents,  may  exist  in  the  uterus  at  the  same  time.  —  The  simplest  case 
of  Superfcetation,  the  frequent  occurrence  of  which  places  it  beyond  reasonable 
doubt,  is  that  in  which  a  female  has  intercourse  on  the  same  day  with  two  males 
of  different  complexions,  and  bears  twins  at  the  full  time;  the  two  infants  resem- 
bling the  two  parents  respectively.  Thus,  in  the  slave-states  of  America,  it  is 
not  uncommon  for  a  black  woman  to  bear  at  the  same  time  a  black  and  a  mulatto 
child ;  the  former  being  the  offspring  of  her  black  husband,  and  the  latter  of  her 
white  paramour.  The  converse  has  occasionally,  though  less  frequently  occurred  : 
a  white  woman  bearing  at  the  same  time  a  white  and  a  mulatto  child.  There  is 

1  "  Journal  of  the  English  Agricultural  Society,"  1839. 

8  "American  Journal  of  the  Medical  Sciences,"  Oc-tober,  1845. 

3  See  especially  two  cases,  183  and  184,  detailed  by  Dr.  Murphy  in  his  "Report  of  the 
Obstetric  Practice  of  University  College  Hospital"  for  1844;  and  another  case  since  pub- 
'ished  by  him  in  the  "  Medical  Gazette  "  for  1849,  vol.  xlviii.  p.  683. 


TRANSMISSION   OF    PARENTAL   CHARACTERS   TO   EMBRYO.  770 

uo  difficulty  in  accounting  for  such  facts,  when  it  is  remembered  that  nothing  has 
occurred  to  prevent  the  uterus  and  ovaria  from  being  as  ready  for  the  second  con- 
ception as  for  the  first;  since  the  orifice  of  the  former  is  not  yet  closed  up ;  and, 
at  the  time  when  one  ovum  is  matured  for  fecundation,  there  are  usually  more  in 
nearly  the  same  condition.  —  But  it  is  not  easy  thus  to  account  for  the  birth  of 
two  children,  each  apparently  mature,  at  an  interval  of  five  or  six  months  ;  since 
it  might  have  been  supposed  that  the  uterus  was  so  completely  occupied  with  the 
first  ovum,  as  not  to  allow  of  the  transmission  of  the  seminal  fluid  necessary  for 
the  fecundation  of  the  second.  In  cases  where  two  children  have  been  produced 
at  the  same  time,  one  of  which  was  fully-formed,  whilst  the  other  was  small  and 
seemingly  premature,  there  is  no  occasion  whatever  to  imagine  that  the  two  were 
conceived  at  different  periods ;  since  the  smaller  foetus  may  have  been  '  blighted/ 
and  its  development  retarded,  as  not  unfrequently  happens  in  other  cases.  Nor 
is  it  necessary  to  infer  the  occurrence  of  superfoetation  in  every  case,  in  which  a 
living  child  has  been  produced  a  month  or  two  after  the  birth  of  another;  since  the 
latter  may  have  been  somewhat  premature,  whilst  the  former  has  been  carried  to 
the  full  term.  But  such  a  difference  can  scarcely  be,  at  the  most,  more  than  2^  or 
3  months;  and  there  are  several  cases  now  on  record,  in  which  the  interval  was 
from  110  to  170  days,  whilst  neither  of  the  children  presented  any  indication  of 
being  otherwise  than  mature.1 

879.  Whatever  be  the  precise  nature  and  history  of  the  Fecundating  process, 
there  can  be  no  doubt  that  the  properties  of  the  Germ  depend  upon  conditions, 
both  material  and  dynamical,  and  supplied  by  loth  Parents.  This  is  most  ob- 
viously shown  by  the  fusion  of  the  characters  of  the  parents,  which  is  exhibited 
by  hybrids  between  distinct  species  or  strongly-marked  varieties  among  the  lower 
animals,  such  as  the  Horse  and  Ass,  the  Lion  and  Tiger,  or  the  various  breeds 
of  Dogs;  or  in  the  offspring  of  parents  belonging  to  two  strongly-contrasted 
Races  of  Men,  such  as  the  European  on  the  one  hand,  and  the  Negro  or  American 
Indian  on  the  other. — It  has  long  been  a  prevalent  idea,  that  certain  parts  of  the 
organism  of  the  offspring  are  derived  from  the  male,  and  certain  other  parts  from 
the  female  parent;  and  although  no  universal  rule  can  be  laid-down  upon  this 
point,  yet  the  independent  observations  which  have  been  made  by  numerous  prac- 
tical '  breeders '  of  domestic  animals  (both  mammals  and  birds),  seem  to  establish 
that  such  a  tendency  has  a  real  existence ;  the  characters  of  the  Animal  portion 
of  the  fabric  being  especially  (but  not  exclusively)  derived  from  the  mak  parent, 
and  those  of  the  Organic  apparatus  being  in  like  manner  derived  from  the  female 
parent.  The  former  will  be  chiefly  manifested  in  the  external  app<virance,  in  the 
general  configuration  of  the  head  and  limbs,  in  the  organs  of  the  senses  (includ- 
ing the  skin),  and  in  the  locomotive  apparatus;  whilst  the  latter  show  themselves 
in  the  size  of  the  body  (which  is  primarily  determined  by  the  development  of  the 
viscera  contained  in  the  trunk),  and  in  the  mode  in  which  the  vita.!  functions  are 
performed.  Thus  the  mule}  which  is  the  produce  of  the  male  ase  and  the  mare, 
is  essentially  a  modified  ass,  having  the  general  configuration  of  its  sire  (slightly 
varied  by  equine  peculiarities),  but  having  the  rounder  trunk  and  larger  size  of 
its  dam;  on  the  other  hand,  the  hinny,  which  is  the  offspring  of  the  stallion  and 
the  she-ass,  is  essentially  a  modified  horse,  having  the  general  configuration  of 
the  horse  (though  with  a  slight  admixture  of  asinine  features),  but  being  a  much 
smaller  animal  than  its  sire,  and  thus  approaching  its  dam  in  size,  as  well  as  in 
the  comparative  narrowness  of  its  trunk.  The  influence  of  the  female  on  the 
general  *  constitution/  and  especially  on  the  fattening,  milking,  and  breeding 
qualities  of  the  offspring,  is  asserted  to  be  proved  by  the  history  of  several  races 
of  sheep  and  cattle,  which  have  been  most  distinguished  in  these  respects.2 — But 
1  See  the  Article  'Superfoetation/  in  Dr.  Beck's  "Elements  of  Medical  Jurisprudence." 
"See  Walker  "On  Intermarriage;''  Orton  on  'The  Physiology  of  Breeding,'  in  the 
"Newcastle  Chronicle,"  March  10,  1854;  and  Dr.  Alex.  Harvey  «0n  the  Relative  Influence 
of  the  Male  and  Female  Parents  in  the  Reproduction  of  the  Animal  Species/  in  "Edinb. 
Monthly  Journ.,"  Aug.  1854. 


780       OF   GENERATION: — ACTION  OF  THE  FEMALE. 

however  general  this  rule  may  prove  to  be  as  regards  the  lower  animals,  it  is  by 
no  means  universal;  for  instances  are  by  no  means  unfrequent,  in  which  the 
multiple  progeny  of  one  conception  divide  between  them  the  characters  of  the 
parents  in  very  different  modes.  Thus,  in  a  case  in  which  a  Setter  bitch,  having 
been  '  lined  '  by  a  Pointer,  bore  three  pups,  two  of  these  pups  seemed  exclusively 
to  resemble  the  father,  appearing  to  be  perfect  Pointers  in  configuration,  and 
growing-up  with  the  habits  of  that  race  ;  whilst  the  third  seemed  equally  to  re- 
semble its  mother,  being  apparently  a  true  Setter  both  in  structure  and  instinct. 
Yet  notwithstanding  this  apparent  restriction,  it  subsequently  appeared  that  the 
pointer-pups  must  h;ive  had  something  of  the  setter  in  their  constitution,  and 
the  setter-pup  something  of  the  pointer.  For  one  of  the  Pointer-pups  (a  male) 
having  been  matched  at  the  proper  age  with  a  Pointer-bitch  of  pure  breed,  one 
of  the  pups  borne  by  the  latter  was  a  true  setter,  exactly  resembling  its  paternal 
grandmother,  and  another  was  setter-marked  ;  and  the  Setter-pup  (a  female)  hav- 
ing been  lined  by  a  Setter-dog  of  pure  breed,  there  were  among  its  litter  of  pups 
two  pointers  resembling  their  maternal  grandfather. — The  same  variety  presents 
itself  to  even  a  greater  degree  in  the  Human  species.  For  in  almost  every  large 
family  (and  sometimes  even  where  there  are  no  more  than  two  children  '),  it  will 
be  observed  that  the  likeness  to  the  father  predominates  in  some  of  the  children, 
and  the  resemblance  to  the  mother  in  others.  Still  it  is  rare  to  meet  with  in- 
stances in  which  some  distinctive  traits  of  loth  parents  may  not  be  traced  in  the 
offspring;  these  traits  often  showing  themselves  in  peculiarities  o£  manner  and 
gesture,  in  tendencies  of  thought  or  feeling,  in  proneness  to  particular  constitu- 
tional disorders,  &c.,  even  where  there  is  no  personal  resemblance,  and  where 
there  has  been  no  possibility  that  these  peculiarities  should  have  been  gained  by 
imitation.  And  even  when  they  are  overborne,  as  it  were,  in  the  immediate 
progeny,  by  the  stronger  influence  derived  from  the  other  side,  they  will  often 
reappear  in  a  subsequent  generation  (as  in  the  case  just  cited),  constituting  the 
phenomenon  known  as  Atavism. 

880.  The  influence  of  both  Parents  on  the  constitution  of  the  Offspring,  is 
strikingly  manifested,  not  merely  in  the  admixture  of  their  characters  normally 
displayed  by  the  latter,  but  also  in  the  tendency  to  the  hereditary  transmission 
of  perverted  modes  of  functional  activity  which  may  have  been  habitual  to  either. 
The  diseases  which  are  usually  considered  to  be  most  prone  thus  to  reappear  in 
successive  generations,  are  Scrofula,  Gout,  Syphilis,  and  Insanity;  but  it  can 
scarcely  be  doubted  that  many  others  might  be  added  to  this  list.2  The  predis- 
position may  have  been  congenital  on  the  part  of  the  parents,  or  it  may  have 
been  acquired  by  themselves;  and  in  no  case  is  this  more  obvious,  than  in  the 
influence  of  Alcoholic  excesses  on  the  part  of  one  or  both*  parents,  in  producing 
Idiocy,  a  predisposition  to  Insanity,  or  weakness  and  instability  of  Mind,  in  the 
children,  this  being  especially  the  case  where  both  parents  have  thus  transgressed. 
Thus  out  of  359  Idiots,  the  condition  of  whose  progenitors  could  be  ascertained, 
it  was  found  that  no  fewer  than  99  were  the  children  of  absolute  drunkards ; 
and  there  was  reason  to  believe  that  a  large  proportion  of  the  parents  of  the  re- 
mainder were  more  or  less  intemperate,  only  about  a  quarter  of  the  whole  number 
of  idiots  having  been  found  to  be  the  children  of  parents  who  were  known  to  be 
temperate.3  And  it  is  perfectly  well  known  to  those  who  are  conversant  with 

1  One  of  the  most  remarkable  cases  of  this  kind  known  to  the  Author,  is  that  of  two 
Sisters,  who  seem  to  resemble  each  other  in  no  one  point  of  configuration  or  mental  cha- 
racter ;  but  of  whom  one  bears  a  most  striking  resemblance,  both  in  person  and  in  mind, 
to  her  Father ;  whilst  the  other  no  less  strikingly  resembles  her  Mother.  The  only  pecu- 
liarities which  at  all  indicate  their  relationship,  are  a  gouty  diathesis  which  they  both  in- 
herit from  their  father,  and  an  idiosyncracy  in  regard  to  opium,  of  which  neither  is  able 
to  take  even  a  small  dose  (in  any  form  whatever)  without  violent  vomiting. 

a  See  the  very  interesting  and  suggestive  Chapter  'On  Hereditary  Disease,' in  Sir  H. 
'Holland's  "  Medical  Notes  and  Reflections." 

1  See  Dr.  Howe's  "Report  on  Idiocy  to  the  Legislature  of  Massachusetts,"  1848. 


HEREDITARY  TRANSMISSION  OF  DISORDERED  STATES  OF  SYSTEM.     781 

Insanity,  that  of  all  the  '  predisposing  causes '  of  that  disorder,  habits  of  intem- 
perance on  the  part  of  either  or  both  parents  are  among  the  most  frequent. — 
The  intensification  which  almost  any  kind  of  perversion  of  Nutrition  derives  from 
being  common  to  both  parents,  is  most  remarkably  evinced  by  the  lamentable  re- 
sults which  too  frequently  accrue  from  the  marriage  of  individuals  nearly  related 
to  each  other,  and  partaking  of  the  same  f  taint.'  Such  results  must  have  fallen 
within  the  knowledge  of  almost  every  one  possessing  an  extended  field  of  obser- 
vation ;  but  they  are  brought-out  with  fearful  vividness  by  the  unerring  test  of 
properly-collected  Statistics.  For  out  of  the  359  idiots  just  referred-to,  17  were 
known  to  have  been  the  children  of  parents  nearly  related  by  blood  ;  and  this  rela- 
tionship was  suspected  to  have  existed  in  several  other  cases,  in  which  positive 
information  could  not  be  obtained.  On  examining  into  the  history  of  the  17 
families  to  which  these  individuals  belonged,  it  was  found  that  they  had  consisted, 
in  all,  of  95  children ;.  that  of  these,  no  fewer  than  44  were  idiotic,  12  others 
were  scrofulous  and  puny,  1  was  deaf,  and  1  was  a  dwarf.  In  some  of  these 
families,  all  the  children  were  either  idiotic,  or  very  scrofulous  and  puny;  in  one 
family  of  8  children,  5  were  idiotic.1 — But  it  does  not  seem  requisite  for  the  pro- 
duction of  very  imperfect  offspring  from  the  intermarriage  of  near  relations,  that 
any  decided  'taint'  should  exist  in  the  parents;  for  the  Author's  own  observa- 
tions and  enquiries  lead  him  to  conclude  that  the  same  danger  results,  when  there 
is  any  strong  personal  or  mental  '  idiosyncracy/  such  as  is  often  seen  «o  run 
through  the  members  (both  male  and  female)  of  a  particular  family,  causing  them 
to  be  at  once  recognized  as  belonging  to  it,  by  those  who  have  been  familiar  with 
other  members.2  This  liability  probably  does  not  exist  to  nearly  the  same  degree, 
where  the  parents,  although  nearly  related,  differ  widely  in  physical  and  in  psy- 
chical characters,  through  the  predominance  of  elements  which  have  been  intro- 
duced by  their  non-related  parents ;  as,  for  example,  when  a  man  who  strongly 
resembles  his  father  rather  than  his  mother,  marries  the  daughter  of  his  mother's 
brother,  who,  on  her  part,  resembles  her  own  mother  rather  than  her  father. 
But  the  case  previously  cited  (§  879)  gives  warning  that  even  here  the  '  family 
idiosyncracy'  may  exist  in  a  powerful  degree,  though  in  a  latent  form,  abd  may 
seriously  affect  the  constitution  of  the  offspring.  It  is  quite  as  common  to  meet 
with  Atavism  in  the  transmission  of  hereditary  disease,  as  in  the  reproduction  of 
'  family  likeness.' 

881.  Attention  has  recently  been  directed  to  a  very  curious  class  of  phenomena, 
which  show  that  where  the  mother  has  previously  borne  offspring,  the  influence 
of  its  father  may  be  impressed  on  her  progeny  afterwards  begotten  by  a  different 
parent;  as  in  the  well-known  case  of  the  transmission  of  Quagga-marks  to  a  suc- 
cession of  colts,  both  whose  parents  were  of  the  species  Horse,  the  mare  having 
been  once  impregnated  by  a  Quagga  male; 3  and  in  the  not  unfrequent  occurrence 
of  a  similar  phenomenon  in  the  Human  species,  as  when  a  widow  who  marries  a 
second  time,  bears  children  strongly  resembling  her  first  husband.  Some  of  these 
cases  appear  referable  to  the  strong  mental  impression  left  by  the  first  male  parent 
upon  the  female  :  but  there  are  others  which  seem  to  render  it  more  likely,  that 
the  blood  of  the  female  has  imbibed  from  that  of  the  foetus,  through  the  placental 
circulation,  some  of  the  attributes  which  the  latter  has  derived  from  its  male 
parent;  and  that  the  female  may  communicate  these,  with  those  proper  to  herself, 

1  See  Dr.  Howe's  Report,  p.  90.  An  abstract  of  this  Report  is  given  in  the  "  Amer- 
Journ.  of  Med.  Sci.,"  April,  1849. 

a  A  most  lamentable  instance  of  this  kind,  -which  happened  some  years  ago,  in  a  family 
well  known  to  the  Author,  was  the  occasion  of  his  first  directing  his  attention  specially  to 
this  point.  Two  first-cousins,  possessing  a  strong  'family  idiosyncracy,'  but  no  definite 
'  taint,'  having  married,  four  children  were  born,  each  of  which  was  distinguished  by  some 
marked  defect  of  organization  or  perversion  of  function ;  one  being  deaf  and  dumb,  an- 
other scrofulous,  a  third  idiotic,  and  the  fourth  epileptic. 

*  "Philosophical  Transactions,"  1821. 


782         OF    GENERATION: ACTION    OF    THE    FEMALE. 

to  the  subsequent  offspring  of  a  different  male  parentage.4 — This  idea  is  borne-out 
by  a  great  number  of  important  facts ;  and  it  serves  to  explain  the  circumstance 
well  known  to  practitioners,  that  secondary  syphilis  will  often  appear  in  a  female 
during  gestation  or  after  parturition,  who  has  never  had  primary  symptoms, 
whilst  the  father  of  the  child  shows  no  recent  syphilitic  disorder.  For  if  he  have 
communicated  a  syphilitic  taint  to  the  foetus,  the  mother  may  become  inoculated 
with  it  through  her  offspring,  in  the  manner  just  described.  As  this  is  a  point 
of  great  practical  importance,  it  may  be  hoped  that  those  who  have  the  opportu- 
nity of  bringing  observation  to  bear  upon  it,  will  not  omit  to  do  so. 

882.  There  seems  good  reason  to  believe,  moreover,  that  the  attributes  of  the 
Germ  are  in  great  degree  dependent,  not  merely  upon  the  habitual  conditions  of 
the  Parents  which  have  furnished  its  original  components,  but  even  upon  the 
condition  in  which  those  parents  may  be  at  the  time  of  sexual  congress.     Of  this 
we  have  a  remarkable  proof  in  the  phenomenon  well  known  to  breeders  of  ani- 
mals, that  a  strong  mental  impression  made  upon  the  female  by  a  particular  male, 
will  give  the  offspring  a  resemblance  to  him,  even  though  she  has  had  no  sexual 
intercourse  with  him,2  a  circumstance  for  which  there  is  no  difficulty  in  account- 
ing, on  the  hypothesis  already  put-forth  regarding  the  dynamical  relation  of  Men- 
tal states  to  the  Organic  processes  (Chap.  XV.).     And  there  is  no  improbability, 
therefore,  in  the  idea,  that  the  offspring  of  parents  ordinarily  healthy  and  tem- 
perate, but  begotten  in  a  fit  of  intoxication  on  both  sides,  would  be  likely  to  suffer 
permanently  from  the  abrogation  of  the  reason,  which  they  have  temporarily 
brought  upon  themselves.3 — On  the  whole,  then,  we  seem  entitled  to  conclude, 
that  the  attributes  of  the  embryo  will  be  influenced  in  a  most  important  degree  by 
the  entire  condition  (as  relates  both  to  the  organic  and  the  psychical  life)  of  both 
parents  at  the  time  of  the  sexual  congress ;  and  it  is  probably  on  account  of  the 
perpetual  changes  taking-place  in  the  bodily  and  mental  state  of  each  individual 
(his  condition  at  any  one  time  being  the  general  resultant  of  all  those  ch-anges), 
that  we  almost  constantly  witness  marked  differences  between  children  born  at 
successive  intervals,  however  strong  may  be  the  'family  likeness'  among  them; 
whilst  the  resemblance  between  twins  is  almost  invariably  much  closer.4 

883.  When  it  is  borne  in  mind,  that  during  the  entire  period  of  gestation,  the 
Embryo  is  deriving  its  nutriment  exclusively  from  the  blood  of  the  Mother,  and 
that  the  condition  of  this  fluid  in  relation  to  her  own  processes  of  Nutrition  and 
Secretion,  is  subject  to  a  very  marked  influence  from  her  own  mental  states 
(Chap,  xv.),  it  cannot  fairly  be  thought  improbable,  that  the  developmental  pro- 
cesses of  the  Embryo  should  be  powerfully  affected  by  strong  Emotional  excite- 
ment on  her  part.     Among  the  facts  of  this  case,  there  is,  perhaps,  none  more 
striking  than   that  quoted  by  Dr.  A.  Combe 5  from  Baron  Percy,  as  having  oc- 
curred after  the  siege  of  Landau  in  1793.     In  addition  to  a  violent  cannonading, 
which  kept  the  women  for  some  time  in  a  constant  state  of  alarm,  the  arsenal 
blew-up  with  a  terrific  explosion,  which  few  could  hear  with  unshaken  nerves. 
Out  of  92  children  born  in  that  district  within  a  few  months  afterwards,  Baron 
Percy  states  that  16  died  at  the  instant  of  birth;  33  languished  for  from  8  to  10 
months,  and  then  died ;  8  became  idiotic,  and  died  before  the  age  of  5  years ; 
and  2  came  into  the  world  with  numerous  fractures  of  the  bones  of  the  limbs, 

1  See  an  interesting  discussion  of  this  question,  by  Dr.  Alex.  Harvey,  in  the  "Edinb. 
Monthly  Journ.,"  Oct.  1849,  and  Oct.  and  Nov.,  1850;  and  in  his  pamphlet  "  On  a  Re- 
markable Effect  of  Cross-Breeding,"  Edinb.,  1851. 

3  See  Harvey,  loc.  cit. 

3  See  a  case  of  this  kind  related  by  Mr.  G.  Combe  in  the  "  Phrenological  Journal,"  vol. 
viii.  p.  471. 

4  Where  twins  are  very  unlike  one  another,  it  will  usually  be  found  that  the  dissimilarity 
is  due  to  the  predominance  of  the  characters  of  the  father  in  one,  and  of  those  of  the  mo- 
ther in  the  other;  as  in  the  case  of  the  Pointer  and  Setter  previously  cited  ($  879). 

1  •'  On  the  Management  of  Infancy,"  p.  76. 


PROGRESS    FROM    THE    GENERAL    TO    THE    SPECIAL.  783 

probably  caused  by  irregular  uterine  contractions.  Here  then  is  a  total  of  59 
children  out  of  92,  or  within  a  trifle  of  2  out  of  every  3,  actually  killed  through 
the  medium  of  the  Mother's  alarm,  and  the  natural  consequences  upon  her  own 
organization;  an  experiment  (for  such  it  is  to  the  Physiologist)  upon  too  large  a 
scale  for  its  results  to  be  set  down  as  mere  l  coincidences/ — No  soundly-judging 
Physiologist  of  the  present  day  is  likely  to  fall  into  the  popular  error,  of  suppos- 
ing that  '  marks '  upon  the  Infant  are  to  be  referred  to  some  transient  though 
strong  impression  upon  the  imagination  of  the  Mother;  but  there  appear  to  be  a 
sufficient  number  of  facts  on  record,  to  prove  that  habitual  mental  conditions  on 
the  part  of  the  Mother  may  have  influence  enough,  at  an  early  period  of  gestation, 
to  produce  evident  bodily  deformity,  or  peculiar  tendencies  of  the  mind  (§  838). 
The  error  of  the  vulgar  notion  on  this  subject,  lies  in  supposing  that  a  sudden  fright. 
speedily  forgotten,  can  exert  such  a  continual  influence  on  the  nutrition  of  tho 
Embryo,  as  to  occasion  any  personal  peculiarity.1  The  view  here  stated,  is  one 
which  ought  to  have  great  weight,  in  making  manifest  the  importance  of  careful 
management  of  the  health  of  the  Mother,  both  corporeal  and  mental,  during  the 
period  of  pregnancy ;  since  the  ultimate  constitution  of  the  offspring  so  much 
depends  upon  the  influences  then  operating  upon  its  most  impressible  structure. 

4. — Development  of  the  Embryo. 

884.  The  history  of  the  revolution  of  the  Germ,  from  its  first  appea.-ance  as  a 
single  cell  lying  in  the  midst  of  the  yolk,  to  the  time  when  it  presents  the  form 
and  structure  characteristic  of  its  parent-species,  and  is  capable  of  maintaining  an 
independent  existence, — including  the  details  of  the  progressive  development  of 
each  separate  organ,  from  its  first  appearance  as  an  aggregation  of  simple  cells 
formed  by  the  duplicative  subdivision  of  the  primordial  vesicle,  to  that  stage  of 
completeness  in  which  it  is  able  to  bear  a  part  in  the  vital  economy  of  the  new 
being, — and  embracing,  also,  the  succession  of  changes  in  the  provisions  for  the 
nutrition  of  the  embryo  in  the  successive  phases  of  its  existence,  and  the  adapta- 
tions of  its  general  organization  to  each  respectively, — constitutes  one  of  the  most 
interesting  departments  of  Physiological  Science,  and  one  which  has  of  late 
years  received  a  peculiar  degree  of  attention.  It  is  a  branch  of  the  inquiry, 
however,  which  has,  and  seems  likely  to  have,  less  practical  bearing  than  any 
other ;  for  neither  as  regards  the  preservation  of  the  body  in  health,  nor  its  resto- 
ration from  disease,  is  it  easy  to  see  what  direct  benefit  the  most  exact  knowledge 
of  Embryonic  Development  is  likely  to  afford.  The  chief  subject  on  which  it 
throws  light,  is  that  of  Congenital  Malformations  and  Deficiencies;  many  of 
which  are  now  distinctly  traceable  to  arrest  or  irregularity  of  the  developmental 
processes;  some  of  them,  indeed,  to  excess  (§  355).  For  these  reasons,  the  topic 
before  us  will  be  passed-over  much  more  lightly  in  the  present  Treatise,  than  its 
scientific  importance  might  seem  to  demand;  and  all  that  will  be  here  attempted 
will  be  a  mere  sketch  of  the  mode  in  which  the  evolution  of  the  germ  takes-place, 
this  being  followed  in  the  first  instance  as  a  whole,  whilst  its  principal  organs  will 
be  afterwards  separately  considered  as  they  successively  present  themselves. — 
This  sketch,  however,  will  serve  to  convey  an  idea  of  the  nature  of  the  process, 
and  to  illustrate  its  conformity  in  Man  to  that  great  law  of  progress  from  the 

1  For  some  valuable  observations  on  this  subject,  see  Montgomery  "  On  the  Signs  of  ' 
Pregnancy." — Numerous  cases  were  recorded  a  few  years  since  (especially  in  the  "Lan- 
cet" and  "  Provincial  Medical  Journal  "),  in  which  malformations  in  the  Infant  appeared 
distinctly  traceable  to  strong  impressions  made  on  the  mind  of  the  Mother  some  months 
previously  to  parturition ;  these  impressions  having  been  persistent  during  the  remaining 
period  of  pregnancy,  and  giving-rise  to  a  full  expectation  on  the  part  of  the  Mother,  that 
the  child  would  be  affected  in  the  particular  manner  which  actually  occurred.  Of  one 
very  striking  case  of  this  kind,  the  Author  is  personally  cognizant,  it  having  occurred  in 
the  family  of  a  near  connection  of  his  own. 


784    OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

general  to  the  special,  which  is  equally  manifested  in  the  development  of  every 
other  organized  being.     (See  PRINC.  OF  COMP.  PHYS.,  Am.  Edit.  Chap,  i.) 

885.  When  we  first  discern  the  primordial  cell  which  is  to  evolve  itself  into 
the  Human  organism,  we  can  trace  nothing  that  essentially  distinguishes  it  from 
that  which  might  give  origin  to  another  form  of  organic  structure,  either  Vege- 
table or  Animal  5  its  condition,  in  fact,  being  permanently  represented  by  the 
humblest  single-celled  Plants  and  Animals.     The  earliest  stages  of  its  develop- 
ment consists  in  simple  multiplication  by  '  duplicative  subdivision '  (PRINC.  OP 
GEN.  PHYS.),  so  that  a  mass  of  cells  comes  to  be  produced,  amidst  the  several 
components  of  which  no  difference  can  be  traced  ;  and  this  also  finds  its  parallel 
among  the  simpler  organisms  of  both  kingdoms.     Soon,  however,  this  homof/c- 
neous  condition  gives  rise  to  a  heterogeneous  one ;  the  further  changes  which  dif- 
ferent parts  of  this  mass  undergo,  not  being  of  the  same  uniform  character,  so 
that  a  marking-out  of  organs,  or  instrumental  parts  adapted  for  different  purposes 
in  the  economy,  comes  to  be  discernible.     The  organs,  however,  whose  distinct- 
ness first  becomes  apparent,  are  not  (for  the  most  part)  those  which  we  trace  in 
the  completed  structure,  but  have  a  merely  temporary  character;  being  evolved 
either  as  a  sort  of  scaffolding  or  frame-work  for  the  building-up  of  the  more  per- 
manent parts,  or  with  a  view  to  the  nutrition  of  the  embryo  during  the  evolution 
of  these.     Although  the  first  indications  of  heterogeneousness  in  the  germinal 
mass  are  of  nearly  the  same  kind  in  all  animals, — consisting  in  the  formation  of 
a  llastodermic  membrane  (composed,  however,  of  nothing  else  than  layers  of  cells) 
upon  its  exterior,  which  serve  as  a  sort  of  temporary  stomach,  whilst  a  large  part 
of  the  included  mass  undergoes  liquefaction,  and  serves  as  the  nutrient  material 
for  the  tissues  which  are  to  be  evolved  from  it, — yet  indications  are  very  speedily 
manifested,  of  the  primary  division  of  the  Animal  Kingdom  of  which  the  new 
being  is  a  member;  thus,  in  the  case  of  the  Human  embryo,  as  of  that  of  all 
Vertebrated  animals,  the  first  outline  of  the  permanent  organization  is  shown  in 
the  'primitive  trace'  which  marks-out  the  line  of  the  vertebral  column  (Plate  II., 
Fig.  11) ;  and  in  this  we  very  soon  discern  the  foundations  of  the  separate  ver- 
tebrae (Fig.  12,  c).     But  there  is  nothing  at  this  period  to  distinguish  the  gorni 
of  Man  from  that  of  any  other  Vertebrated  animal,  this  early  part  of  the  develop- 
mental process  being  carried-on  upon  the  same  plan  in  every  member  of  that  sub- 
kingdom  ;  and  it  is  not  until  we  meet  with  indications  of  one  of  the  plans  which 
are  peculiar  to  the  respective  classes  of  that  sub-kingdom,  that  we  can  discover 
whether  the  germ  in  course  of  evolution  is  to  become  a  Mammal,  Bird,  Reptile, 
or  Fish.    So,  even  when  it  has  been  recognized  as  belonging  to  the  Mammalian  class, 
there  is  at  first  nothing  to  distinguish  it  from  that  of  any  other  Mammal;  and  it 
is  only  with  the  advance  of  the  developmental  process,  that  indications  succes- 
sively present  themselves,  which  enable  us  to  distinguish,  one  after  another,  the 
characters  of  the  order,  the  family,  the  genus,  the  species,  the  variety,  the  sex, 
and  the  individual, — the  more  special  features  progressively  evolving  themselves 
out  of  the  more  general,  which  is  the  expression  of  the  law  of  development  com- 
mon to  all  Organized  beings.     (See  PRINC.  OF  COMP.  PHYS.,  Am.  Edit.Ch.  xv.) 
886.  With  this  progressive  alteration  in  the  condition  of  the  embryo  itself,  a 
very  remarkable  series  of  alterations  is  proceeding,  pari  passu,  in  the  mode  in 
which  it  is  supplied  with  nutrient  material,  and  in  the  provisions  for  the  aeration 
of  its  circulating  fluid.  —  The  first  evolution  of  the  germ  takes-place  entirely  at 
the  expense  of  the  yolk;  of  which,  however,  the  store  contained  in  the  Mamma- 
lian ovum  is  very  small.     The  whole  of  this  is  very  speedily  incorporated  in  the 
substance  of  the  germ,  by  the  peculiar  process  to  be  presently  described ;  and 
there  is  no  residual  store  of  *  food-yolk/  such  as  that  which,  in  the  Bird,  serves 
for  the  nutrition  of  the  embryo  during  the  whole  remainder  of  the  developmental 
process,  by  being  gradually  absorbed  into  the  substance  of  the  blastodermic  mem- 
brane, and  there  converted  into  blood.     The  Mammalian   ovum,  however,  from 
the  time  it  reaches  the  Uterus,  is  furnished  with  a  new  supply  of  nourishment. 


PROGRESS    FROM    THE    GENERAL    TO    THE    SPECIAL.  785 

in  the  fluid  secreted  by  the  Decidual  membrane  (§  863) ;  and  for  the  absorption 
of  this,  it  is  particularly  adapted  by  the  villosities  which  develope  themselves 
from  its  own  external  envelope.  These,  at  first  entirely  destitute  of  blood-vessels, 
are  subsequently  penetrated  at  a  certain  part  of  the  surface,  by  the  foetal  capil- 
laries brought  to  them  by  an  organ,  the  Allantois,  which  is  developed  in  Birds  as 
(the  temporary  instrument  of  respiration ;  and  thus  is  originated  the  foetal  portion 
of  the  Placenta,  of  whose  formation  an  account  will  be  presently  s^iven  (§  893). 
From  the  time  that  this  organ  is  completed,  up  to  the  birth  of  the  Infant,  the 
embryo  draws  its  nutrient  materials  direct  from  the  maternal  blood,  though  not 
receiving  that  blood  an  such  into  its  own  organism ;  and  it  is  through  the  same 
medium  that  the  aeration  of  its  own  blood  is  effected,  its  pulmonary  apparatus 
being  as  yet  inoperative.  Its  circulating  system,  arranged  in  accordance  with 
these  requirements,  presents  many  peculiarities  which  mark  its  foetal  character ; 
and  the  alteration  in  the  course  of  the  blood,  which  takes-place  as  soon  as  the 
respiratory  organs  come  into  play,  constitutes  the  essential  difference  between 
intra-uterine  and  extra-uterine  life.  If,  as  sometimes  happens,  the  lungs  of  the 
new-born  infant  expand  but  imperfectly  or  scarcely  at  all,  the  circulation  con- 
tinues to  be  carried-on,  in  a  greater  or  less  degree,  upon  its  intra-uterine  plan  j 
and  this,  when  the  placenta  is  no  longer  capable  of  supplying  the  needed  aeration, 
is  incompatible  with  the  persistence  of  life. 

887.  Our  knowledge  of  the  first  stages  of  the  developmental  process  in  the 
Mammalian  ovum,  is  in  many  respects  incomplete ;  and  it  is  requisite  to  inter- 
pret what  has  been  obscurely  seen  in  the  ova  of  this  class,  by  the  clearer  views 
derived  from  observation  of  those  of  the  lower  animals.1  —  As  already  stated 
(§  861),  the  germinal  vesicle  disappears  at  or  about  the  time  of  fecundation ;  but 
its  disappearance  is  not  a  result  of  fecundation,  since  it  also  takes-place  in  the 
uniinpregnated  egg,  in  consequence  (it  may  be  presumed)  of  the  completion  of 


Cleaving  of  the  yolk  after  fecundation :  A,  B,  c  (from  Kolliker),  ovum  of  Ascaris  nigrove- 
nosa;  D  and  E,  that  of  Ascaris  acuminata  (from  Bagge).] 

its  term  of  life,  and  of  those  operations  which  it  was  developed  to  perform.  Its 
place  is  seen  to  be  occupied,  at  an  early  period  after  fecundation,  by  a  new  and 
peculiar  cell,  the  origin  of  which  is  obscure,  but  the  destination  of  which  is  most 
important  j  for  it  is  by  the  '  duplicative  subdivision  of  this  cell,  first  into  2,  then 
into  4,  then  into  8,  and  so  on,  and  by  the  metamorphoses  which  its  progeny  un- 
dergo, that  the  whole  embryonic  fabric  is  gradually  evolved.  Hence  this  cell 
may  be  termed  the  embryo-cell.2  At  the  same  time,  a  peculiar  change  begins  to 
take  place  in  the  yolk,  the  whole  sphere  of  which  is  first  marked-out  by  a  furrow 

'  The  researches  of  Kolliker  ("  Miiller's  Archiv.,"  1843,  p.  68)  and  Bagge  ("De  Evolut. 
Strongyli  et  Ascarid.,  Diss.  Inaug.,"  1841)  on  the  ova  of  Entozoa, — those  of  Mr.  Newport 
("  Philos.  Transact.,"  1851)  on  the  ova  of  Batrachia, — and  those  of  Bischoff  ("Entwicke- 
lungsgeschichte  des  Hunde-eies,"  1845)  on  the  ova  of  the  Bitch, —  are  among  the  most 
valuable  which  we  at  present  possess. 

2  The  embryo-cell  has  not  yet  been  clearly  made-out  in  the  Mammalian  ovum ;  but 
from  the  conformity  of  the  subsequent  appearances  to  those  which  are  seen  in  the  ova  of 
the  lower  animals,  there  is  every  reason  to  believe  that  the  formation  of  either  a  complete 
cell,  or  of  a  nucleus  having  the  same  essential  endowments,  is  a  preliminary  to  the  cleav 
age  of  the  yolk. 

50 


786     OF    GENERATION:  —  EMBRYONIC    DEVELOPMENT. 

into  two  hemispheres,  and  is  at  last  completely  divided  by  the  extension  of  this 
fission  to  the  centre;  each  half  is  again  furrowed  and  then  cleft  in  the  same 
manner,  and  thus  the  entire  yolk  is  broken  up  into  a  m-ass  of  segments  (Fig. 
219).  This  'segmentation7  takes  place pari passu  with  the  multiplication  of  the 


Progressive  stages  in  the  Segmentation  of  the  Yolk  of  the  Mammalian  Ovum : — A,  its 
first  division  into  two  halves ;  B,  subdivision  of  each  half  into  two ;  c,  further  subdivision, 
producing  numerous  segments. 

embryo-cells,  each  of  which  is  surrounded  by  a  distinct  portion  of  the  yolk ;  and 
there  seems  every  probability  that  it  is  determined  by  that  multiplication,  and 
that  each  cell  of  the  pair  that  is  formed  by  the  duplicative  subdivision  of  its 
predecessor,  draws  around  itself  its  proper  share  of  the  nutritive  material.  — 
These  changes  take-place  in  the  Mammalian  Ovum,  during  its  transit  along  the 
Fallopian  tube  to  the  uterus  j  so  that,  by  the  time  of  its  arrival  there,  the  whole 
cavity  of  the  Zona  pellucida  is  occupied  by  minute  spherules  of  yolk,  each  con- 
taining a  transparent  vesicle,1  the  aggregation  of  which  gives  it  a  mulberry-like 
aspect  (Fig.  220,  A);  and  by  a  continuance  of  the  same  process  of  subdivision, 

FIG.  220. 


Later  stage  in  the  Segmentation  of  the  Yolk  of  the  Mammalian  Ovum  : — at  A  is  shown 
the  'mulberry  mass'  formed  by  the  minute  subdivision  of  the  vitelline  spheres ;  at  B,  a 
further  increase  has  brought  its  surface  into  contact  with  the  vitelline  membrane,  against 
wiiich  the  spherules  are  flattened. 

the  component  segments  becoming  more  and  more  minute,  the  mass  comes  to 
present  a  finely-granular  aspect  (B). 

888.  At  this  stage,  it  does  not  appear  that  the  several  segments  of  the  yolk 
have  a  distinct  enveloping  membrane ;  but  an  envelope  is  now  formed  around 
each  of  them,  converting  it  into  a  cell,  of  which  the  included  vesicle  constitutes 
the  nucleus,  and  of  which  the  portion  of  the  yolk  surrounding  this  forms  the 

1  It  is  by  no  means  certain  that  this  vesicle  is  a  true  cell  in  the  Mammalian  ovum  (as 
it  seems  clearly  to  be  in  the  ovum  of  many  of  the  lower  animals),  its  appearance,  when 
liberated  from  the  yolk-granules  which  surround  it,  being  rather  that  of  a  fat,  or  oil- 
p;lobule. 


FIRST    MARKING-OUT    OF    FORM    OF    EMBRYO.          787 

contents.  This  happens  first  to  the  peripheral  portions  of  the  mass;  and  as  its 
cells  are  fully  developed,  they  arrange  themselves  at  the  surface  of  the  yolk  into 
a  kind  of  membrane,  and  at  the  same  time  assume  a  pentagonal  or  hexagonal 
shape  from  mutual  pressure,  so  as  to  resemble  pavement-epithelium  (Plate  I., 
Fig.  5).  As  the  globular  masses  of  the  interior  are  gradually  converted  into 
cells,  they  also  pass  to  the  surface  and  accumulate  there,  thus  increasing  the 
thickness  of  the  membrane  already  formed  by  the  more  superficial  layer  of  cells, 
while  the  central  part  of  the  mass  remains  occupied  only  by  a  clear  fluid.  By  this 
means  the  exterior  of  the  yolk  is  speedily  converted  into  a  kind  of  secondary 
vesicle,  situated  within  the  Zona  pellucida,  and  named  by  Bischoif  the  blastoder- 
mic  vesicle.  This  vesicle,  very  soon  after  its  formation,  presents  at  one  point  an 
opaque,  roundish  spot  (Plate  I.,  Fig.  6),  which  is  produced  by  an  accumulation 
of  cells  and  nuclei  of  less  transparency  than  elsewhere  ;  this  is  termed  the  area 
germinativa.  The  wall  of  the  vesicle,  which  is  termed  the  germinal  membrane, 
increases  in  extent  and  thickness,  by  the  formation  of  new  cells  (whose  mode  of 
production  has  not  been  clearly  made-out) ;  and  it  subdivides  into  two  layers 
(Plate  I.,  Fig.  7),  which,  although  both  at  first  composed  of  cells,  soon  present 
distinctive  characters,  and  are  concerned  in  very  different  ulterior  operations. 
The  outer  one  of  these  is  commonly  known  as  the  serous  layer  (Fig.  8) ;  but 
being  the  one  in  whose  substance  the  foundation  is  laid  for  the  vertebral  column 
and  the  nervous  system,  it  is  sometimes  called  the  animal  layer.  The  inner  one 
is  usually  known  as  the  mucous  layer  (Fig.  9);  and  being  the  one  chiefly  con- 
cerned in  the  formation  of  the  nutritive  apparatus,  it  is  sometimes  called  the 
vegetative  layer.  This  division  is  at  first  most  evident  in  the  neighbourhood  of 
the  area  germinativa;  but  it  soon  extends  from  this  point,  and  implicates  nearly 
the  whole  of  the  germinal  membrane. 

889.  The  Area  Germinativa  at  its  first  appearance  has  a  rounded  form ;  but 
it  soon  loses  this,  first  becoming  oval,  and  then  pear-shaped  (Plate  II.,  Fig.  11). 
While  this  change  is  taking-place  in  it,  there  gradually  appears  in  its  centre  a 
clear  space,  termed  the  area  pellucida  (a);  and  this  is  bounded  externally  by  a 
more  opaque  circle  (whose  opacity  is  due  to  the  greater  accumulation  of  cells  and 
nuclei  in  that  part  than  in  the  area  pellucida),  which  subsequently  becomes  the 
area  vasculosa.  In  the  formation  of  these  two  spaces,  both  the  serous  and  the 
mucous  layers  of  the  germinal  membrane  seem  to  take  their  share  ;  but  the  foun- 
dation of  the  embryonic  structure,  known  as  the  primitive  trace,  is  laid  in  the 
serous  lamina  only  (Fig.  221).  This  consists  in  a  shallow  groove  (c),  lying  between 
two  masses  (Z>),  known  as  the  laminae  dorsales,  whose  form  changes  with  that  of 
the  area  pellucida,  being  at  first  oval,  then  pyriform,  and  at  last  becoming  guitar- 
shaped  ;  they  also  rise  more  and  more  from  the  surface  of  the  area  pellucida,  so  as 
to  form  two  ridges  of  higher  elevation,  with  a  deeper  groove  between  them ;  and  the 
summits  of  these  ridges  tend  to  approach  each  other,  and  gradually  unite,  so  as 
to  convert  the  groove  into  a  tube.  At  the  same  time,  the  anterior  portion  of  the 
groove  dilates  into  three  recesses  or  vesicles  (Plate  II.,  Fig.  12,  b),  which  indi- 
cate the  position  of  the  three  principal  divisions  of  the  Encephalon,  afterwards 
to  be  developed  as  the  proscencephalon,  the  mesencephaJon  and  the  epencephalon 
(§  909).  The  most  internal  parts  of  these  laminae,  bounding  the  bottom  and 
sides  of  the  groove,  appear  to  furnish  the  rudiments  of  the  nervous  centres  which 
this  cranio-vertebral  canal  is  to  contain;  whilst  the  outer  parts  are  developed  into 
the  rudiments  of  the  vertebral  column  and  cranium.  Even  before  the  laminae 
dorsales  have  closed  over  the  primitive  groove,  a  few  square-shaped  and  at  first 
indistinct  plates  (c),  which  are  the  rudiments  of  vertebrae,  begin  to  appear  a*fc 
about  the  middle  of  each.  The  position  of  the  bodies  of  the  vertebrae  is  indi- 
cated at  this  period,  in  the  enibryoes  of  Birds  and  Fishes,  by  a  distinct  cylin- 
drical rod  of  nucleated  cells,  termed  the  chorda  dorsalis ;  and  this  retains  its 
embryonic  type  in  the  Myxinoid  Fishes  (§  906).  While  this  is  going-on.  an  ac- 
cumulation of  cells  takes-place  between  the  two  lamina!  of  the  germinal  mem- 


788  OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

brane  at  the  '  area  vasculosa ;'  and  these  cells  speedily  form  themselves  into  a 
distinct  layer,  the  vascular  lamina,  in  which  the  first  blood-vessels  of  the  embryo 
are  developed,  as  will  be  presently  described  (§  890).  From  the  dorsal  lamina 
on  either  side,  a  prolongation  passes  outwards  and  then  downwards,  forming 
what  is  known  as  the  ventral  lamina;  in  this  are  developed  the  ribs  and  the 
transverse  processes  of  the  vertebraa;  and  the  two  have  the  same  tendency  to 
meet  on  the  median  line,  and  thus  to  close-in  the  abdominal  cavity  which  the 
dorsal  laminae  have  to  enclose  the  spinal  cord.  At  the  same  time,  the  layers  of 
the  germinal  membrane  which  lie  beyond  the  extremities  of  the  embryo,  are 
folded-in,  so  as  to  make  a  depression  on  the  yolk;  and  their  folded  margins  gra- 
dually approach  one  another  under  the  abdomen.  The  first  rudiment  of  the  In- 
testinal canal  presents  itself  as  a  channel  along  the  under  surface  of  the  embryo- 
nic mass,  formed  by  the  rising-up  of  the  inner  layer  of  the  germinal  membrane 
into  a  ridge  on  either  side.  The  two  ridges  gradually  arch-over  and  meet,  so  as 
to  form  a  tube,  which  is  thus  (so  to  speak)  pinched-off  from  the  general  vitelline 
sac ',  and  it  remains  in  connection  with  this,  by  means  of  an  unclosed  portion, 
which  constitutes  the  'vitelline  duct'  (Figs.  223,  224,  228). 

890.  Whilst  these  new  structures  are  being  produced,  a  very  remarkable  change 
is  taking-place  in  that  part  of  the  serous  lamina  which  surrounds  the  area  pellu- 
cida  This  rises-up  on  either  side  in  two  folds  (Fig.  221,  <7,  e)  ;  and  these  gra- 

FIG.  222. 


Fig.  221. — Plan  of  early  Uterine  Ovum.  Within  the  external  ring,  or  zona  pellucida,  are 
the  serous  lamina,  a;  the  yolk,  b;  and  the  incipient  embryo,  c. 

Fig.  222. — Diagram  of  Ovum  at  the  commencement  of  the  formation  of  the  Amnion: — a, 
chorion;  6,  yolk-sac;  c,  embryo;  d,  and  e,  folds  of  the  serous  layer  rising-up  to  form  the 
amnion. 

dually  approach  one  another  (Fig.  223),  at  last  meeting  in  the  space  between  the 
general  envelope  and  the  embryo,  and  thus  affording  an  additional  investment  to 
the  latter  (Fig.  224).  As  each  fold  contains  two  layers  of  membrane,  the  in 
vestment  thus  formed  is  double;  of  this,  the  outer  lamina  adheres  to  the  general 
envelope  ;  whilst  the  inner  remains  as  a  distinct  sac,  to  which  the  name  of  Am- 
nion is  given.  This  takes-place  during  the  third  day  in  the  Chick;  the  date  at 
which  it  occurs  in  the  Human  ovum  is  difficult  to  be  ascertained,  owing  to  the 
small  number  of  normal  specimens  which  have  come  under  observation  at  a  suffi- 
ciently early  stage. — During  the  same  period,  a  very  important  provision  for  the 
future  support  of  the  embryo  begins  to  be  made,  by  the  development  of  Blood- 
vessels and  the  formation  of  Blood.  Hitherto,  the  embryonic  structure  has  been 
nourished  by  direct  absorption  of  the  alimentary  materials  supplied  to  it  by  the 
yolk ;  but  its  increasing  size,  and  the  necessity  for  a  more  free  communication 
between  its  parts  than  any  structure  consisting  of  cells  alone  can  permit,  call  for 
the  development  of  vessels  through  which  the  nutritious  fluid  may  be  conveyed. 
These  vessels  are  first  seen  in  that  part  of  the  Vascular  lamina  of  the  germinal 
membrane,  which  immediately  surrounds  the  embryo ;  and  they  form  a  network, 
bounded  by  a  circular  channel,  which  is  known  under  the  name  of  the  Vascular 


FORMATION    OF    HEART   AND     FIRST    BLOOD-VESSELS.  789 

Area  (Plate  IT,  Fig.  13).  This  gradually  extends  itself,  until  the  vessels  spread 
over  the  whole  of  the  membrane  that  contains  the  yolk.  The  first  blood-discs 
appear  to  be  formed  from  certain  cells  which  are  set-free  by  the  liquefaction  of 
others  around  them  to  form  the  vessels  (§  167) ;  and  from  these,  the  subsequent 
blood-discs  of  the  first  series  are  probably  generated.  This  network  of  blood-ves- 
sels serves  the  purposes  of  absorbing  the  nutritious  matter  of  the  yolk,  and  of 
conveying  it  towards  the  embryonic  structures  which  are  now  in  process  of  rapid 
development.  The  first  movement  of  the  fluid  is  towards  the  embryo;  and  this 
can  be  witnessed  before  any  distinct  heart  is  evolved.  The  same  process  of  ab- 
sorption from  the  yolk,  and  of  conversion  into  blood,  probably  continues  as  long 
as  there  is  any  alimentary  material  left  in  the  sac. 

891.  The  Yolk-sac  is  entirely  separated  in  the  Mammalia,  by  a  constriction  of 
the  portion  which  is  continuous  with  the  abdomen  of  the  embryo  (Fig.  224,  5) ; 
and  it  is  known  from  that  time  under  the  name  of  the  Umbilical  Vesicle  (Plate 
I,  Fig.  10,  i).     The  communication,  however,  remains  open  for  a  time  through 
the  'vitelline  duct;'  and  even  after  this  has  been  cut-off,  the  trunks  which  con- 
nect the  circulating  system  of  the  embryo  with  that  of  the  vascular  area  are  dis- 
cernible ;    these    are    called    Omplialo-Mesenteric,  Meseraic,  or  Vitelline  vessels 
(Figs.  224,  225,  q,  r).     It  was  formerly  believed  that  the  nutrient  matter  of  the 
yolk  passes  directly  through  the  vitelline  duct,  into  the  (future)  digestive  cavity 
of  the  embryo,  and  is  from  it  absorbed  into  its  structure ;  but  there  can  now  be 
little  doubt,  that  the  vitelline  vessels  are  the  real  agents  of  its  absorption,  and 
that  they  convey  it  through  the  general  circulating  system,  to  the  tissues  in  pro- 
cess of  formation.     They  correspond,  in  fact,  to  the  Mesenteric  veins  of  Inverte- 
brated  animals,  which   are  the  sole  agents  in  the  absorption  of  nutriment  from 
their  digestive  cavity  (PRiNC.  OF  COMP.  PHYS.,  Am.  Ed.,  Chap,  rv.);  and  the 
blastodermic  vesicle  is  to  be  regarded  as  the  temporary  stomach  of  the  embryo,-*- 
remaining  as  the  permanent  stomach  in  the  Radiated  tribes.1 

892.  The  formation  of  the  Heart,  which  is  the  first  of  the  permanent  organs 
of  the  Embryo  that  comes  into  functional  activity,  takes-place  in  the  substance  of 
the  vascular  layer,  beneath  the  upper  part  of  the  spinal  column.     Its  first  rudi- 
ment consists  of  an  aggregation  of  cells,  of  which  the  interior  break-down  to  form 
its  cavity,  whilst  the  outer  remain  to  constitute  its  walls.     For  a  long  time  after 
it  has  distinctly  commenced  pulsating,  and  is  obviously  exerting  a  contractile  force, 
its  walls  obviously  retain  the  cellular  character,  and  only  become  muscular  by  a  pro- 
gressive histological  transformation  (PaiNC.  OF  GEN.  PHYS.,  Am.  Ed.).    The  first 
appearance  of  the  Heart  in  the  Chick  is  at  about  the  27th  hour;  the  time  of  its 
formation  in  Mammalia  has  not  been  distinctly  ascertained.     In  its  earliest  form, 
it  has  the  same  simple  character  which   is  presented   by  the  central  impelling 
cavity  of  the  lower  Invertebrata ;  being  a  mere  prolonged  canal,  which  at  its  pos- 
terior extremity  receives  the  veins,  and  at  its  anterior  sends-forth  the  arteries. 
After  a  short  time,  however,  it  becomes  bent  upon  itself  (Plate  II,  Fig.  13,  d); 
and  it  is  soon  subdivided  into  three  cavities,  which  exist  in  all  Vertebrata,  viz., 

1  Previously  to  the  ninth  day  of  incubation  (in  the  Fowl's  egg),  a  series  of  folds  are 
formed  by  the  lining  membrane  of  the  yolk-bag,  which  project  into  its  cavity  ;  these  become 
gradually  deeper  and  more  crowded,  as  the  bag  diminishes  in  size  by  the  absorption  of  its 
contents.  The  vitelline  vessels  that  ramify  upon  the  yolk-bag,  send  into  these  folds  (or 
valvulse  conniventes)  a  series  of  inosculating  loops,  which  immensely  increase  the  extent 
of  this  absorbing  apparatus.  But  these  minute  vessels  are  not  in  immediate  contact  with 
the  yolk ;  for  there  intervenes  between  them  (as  was  first  noticed  by  Mr.  Dalrymple)  a 
layer  of  nucleated  cells,  which  is  easily  washed  away.  (See  Dr.  Baly's  Translation  of 
"Miiller's  Physiology,"  pp.  1557-1559).  It  was  from  the  colour  of  these,  communicated 
to  the  vessels  beneath,  that  Haller  termed  the  latter  vasa  lutea ;  when  the  layer  is  removed, 
the  vessels  present  their  usual  colour.  There  seems  good  reason  to  believe  that  these 
cells,  like  those  of  the  Intestinal  Villi  in  the  adult  (§  121),  are  the  real  agents  in  the  pro- 
cess of  absorbing  and  assimilating  the  nutritive  matter  of  the  yolk  ;  and  that  they  deliver 
this  up  to  the  vessels,  by  themselves  undergoing  rupture  or  dissolution,  being  replaced  by 
new  layers. 


790     OF   GENERATION: — EMBRYONIC  DEVELOPMENT. 

a  simple  auricle  or  receiving  cavity,  a  simple  ventricle  or  propelling  cavity,  and  a 
bulbvs  arteriosm  at  the  origin  of  the  aorta.  The  circulation  is  at  first  carried-on 
exactly  upon  the  plan  which  is  permanently  exhibited  by  Fishes.  The  Aorta 
subdivides  on  either  side  of  the  neck  into  four  or  five  arches  (Figs.  225,  226,  c, 
e',  e"),  which  are  separated  by  fissures  much  resembling  those  forming  the  en- 
trances to  the  gill-cavities  of  Cartilaginous  Fishes;  and  these  arches  re-unite  to 
form  the  descending  aorta,  which  transmits  branches  to  all  parts  of  the  body. — 
Such  is  the  first  phase  or  aspect  of  the  Circulating  Apparatus,  which  is  common 
to  all  Vertebrata  during  the  earliest  period  of  their  development,  and  which  may, 
therefore,  be  considered  as  its  most  general  form.  It  remains  permanent  in  the 
class  of  Fishes;  and  in  them  the  vascular  system  undergoes  further  development 
on  the  same  type,  a  number  of  minute  tufts  being  sent-forth  from  each  of  the 
arches,  which  enter  the  filaments  of  the  gills,  and  are  thus  subservient  to  the 
aeration  of  the  blood.  In  higher  Vertebrata,  however,  the  plan  of  the  circulation 
is  afterwards  entirely  changed,  as  will  be  presently  described,  by  the  formation  of 
new  cavities  in  the  heart,  and  by  the  production  of  new  vessels ;  it  is  incorrect, 
therefore,  to  speak  of  the  vascular  arches  in  their  necks  as  branchial  arches,  since 
no  branchiae  or  gills  are  ever  developed  from  them.  The  clefts  between  them 
may  be  very  distinctly  seen  in  the  Human  Foetus  towards  the  end  of  the  first 
month ;  during  the  second,  they  usually  close-up  and  disappear. 

893.  With  the  evolution  of  a  Circulating  apparatus,  adapted  to  absorb  nourish- 
ment from  the  store  prepared  for  the  use  of  the  Embryo,  and  to  convey  it  to  its 
different  tissues,  it  becomes  necessary  that  a  Respiratory  apparatus  should  also  be 
provided,  for  depurating  the  blood  from  the  carbonic  acid  with  which  it  becomes 
charged  during  the  course  of  its  circulation.  The  temporary  Respiratory  appara- 
tus now  to  be  described,  bears  a  strong  resemblance  in  its  own  character,  and  es- 
pecially in  its  vascular  connections,  to  the  gills  of  the  Mollusca ;  which  are  pro- 
longations of  the  external  surface  (usually  near  the  termination  of  the  intestinal 
canal),  and  which  almost  invariably  receive  their  vessels  from  that  part  of  the 
system.  This  apparatus,  which  is  termed  the  Allantois,  sprouts-forth  from  the 
caudal  extremity  of  the  embryo,  at  first  as  a  little  mass  of  cells,  which  soon  exhi- 
bits a  cavity  (probably  originating  in  the  liquefaction  of  the  cells  of  the  internal 
part),  so  that  a  vesicle  is  formed  (Figs.  223,  224,  #),  which  looks  like  a  diverti- 

FIG.  224. 


Fig.  223. — Diagram  of  an  early  Human  Ovum,  showing  the  Amnion  in  process  of  formation, 
and  the  Allantoia  beginning  to  appear: — a,  chorion ;  b,  vitelline  mass  surrounded  by  the  blas- 
todermic  vesicle  ;  c,  embryo  ;  d,  e,  and/,  external  and  internal  folds  of  the  serous  layer,  form- 
ing the  amnion  ;  <jr,  incipient  allantois. 

Fig.  224. — Diagram  of  a  Human  Ovum  in  second  month,  showing  the  completion  of  the  sac 
of  the  Amnion,  and  a  further  development  of  the  Allantoia  :  a  1,  smooth  portion  of  chorion ; 
a  2,  villous  portion  of  chorion ;  k,  k,  elongated  villi,  beginning  to  collect  into  Placenta;  b,  vi- 
'elline  or  umbilical  vesicle;  e,  embryo;/,  amnion  (inner  layer);  g,  allantois;  Ti,  outer  layer  of 
-uanion,  coalescing  with  chorion. 


ALLANTOIS. LIQUOR    AM  Nil. UMBILICAL    CORD.    791 

culum  from  the  lower  part  of  the  digestive  cavity.  This  vesicle,  in  Birds,  soon 
becomes  so  large  as  to  extend  itself  around  the  whole  yolk-sac,  intervening  be- 
tween it  and  the  membrane  of  the  shell,  and  coming  through  the  latter  into  rela- 
tion with  the  external  air;  but  in  the  embryo  of  Mammalia,  the  allantois,  being 
early  superseded  by  another  provision  for  the  aeration  of  the  blood,  seldom  attains 
any  considerable  dimensions.  Its  chief  office  here  is  to  convey  the  vessels  of  the 
embryo  to  the  chorion ;  and  its  extent  bears  a  pretty  close  correspondence  with 
the  extent  of  surface,  through  which  the  chorion  comes  into  vascular  connection 
with  the  decidua.  Thus,  in  the  Carnivora,  whose  placenta  extends  like  a  band 
around  the  whole  ovum,  the  allantois  also  lines  nearly  the  whole  inner  surface  of 
the  chorion;  on  the  other  hand,  in  Man  and  the  Quadrumana,  whose  placenta  is 
restricted  to  one  spot,  the  allantois  is  small,  and  conveys  the  foetal  vessels  to  one 
portion  only  of  the  chorion.  When  these  vessels  have  reached  the  chorion,  they 
ramify  in  its  substance,  and  send  filaments  into  its  villi ;  and  in  proportion  as  these 
villi  form  that  connection  with  the  uterine  structure  which  has  been  already  de- 
scribed (§§  866,  867),  do  the  vessels  increase  in  size.  They  then  pass  directly 
from  the  foetus  to  the  chorion ;  and  the  allantois,  being  no  longer  of  any  use, 
shrivels-up,  and  remains  as  a  minute  vesicle,  only  to  be  detected  by  careful  exa- 
mination. The  same  thing  happens  in  regard  to  the  umbilical  vesicle,  from  which 
the  entire  contents  have  been  by  this  time  withdrawn ;  and  from  henceforth  the 
foetus  is  completely  dependent  for  the  materials  of  its  growth  upon  the  supply  it 
receives  through  the  Placenta,  which  is  conducted  to  it  by  the  vessels  of  the  um- 
bilical cord.  This  state  of  things  is  represented  in  Figs.  225,  226,  ??,  nf,  o,  o'. 
T— The  Allantois  is  commonly  said  to  give  origin  to  the  Urinary  Bladder ;  but 
this  organ  is  really  formed  by  an  enlargement  of  the  upper  part  of  the  uro-genital 
sinus  (§  904),  with  which  the  allantois  communicates  by  a  duct  which  gradually 
shrivels,  only  a  vestige  of  it  remaining  permanent,  to  form  the  Urachus  or  sus- 
pensory ligament  of  the  bladder,  by  which  this  is  connected  with  the  umbilicus. 
Before  this  takes- place,  however,  the  Allantois  is  the  receptacle  for  the  secretion 
of  the  Corpora  Wolffiana,  and  also  for  that  of  the  true  Kidneys,  when  they  are 
formed  (§  902). 

894.  It  will  be  seen  from  the  succeeding  diagram,  that  the  Amnion  forms  a 
kind  of  tubular  sheath  around  the  umbilical  cord ;  it  is  continuous  at  the  umbi- 
licus with  the  integument  of  the  foetus;  and  at  the  point  where  the  cord  enters 
the  placenta,  it  is  reflected  over  its  internal  or  foetal  surface.  It  thus  forms  a 
shut  sac,  resembling  that  of  the  pleura,  arachnoid,  &c. ;  and  it  contains  a  fluid, 
known  as  the  liquor  amnii,  which  consists  of  water  holding  in  solution  a  small 
quantity  of  albumen  and  saline  matter,  and  resembling,  therefore,  very  diluted 
serum.  During  the  first  two  months  of  gestation,  the  amnion  and  the  inner 
lining  of  the  chorion  (which  is  really  the  reflected  layer  of  the  amnion,  Fi.£. 
224,  h,  just  as  the  lining  of  the  abdominal  cavity  is  formed  by  the  peritoneum) 
are  separated  by  a  gelatinous-looking  substance;  which  probably  aids  in  the 
nutrition  of  the  embryo,  previously  to  the  formation  of  the  placenta.  This  is 
absorbed  during  the  second  month ;  and  the  amnion  is  then  found  immediately 
beneath  the  chorion. — In  the  Umbilical  Cord,  when  it  is  completely  formed,  the 
following  parts  may  be  traced.  1.  The  tubular  sheath  afforded  by  the  Amniou. 
2.  The  Umbilical  Vesicle  (Fig.  225,  t),  with  its  pedicle,  or  vitelline  duct.  3.  The 
Vasa  Oniphalo-Meseraica  (g,  r),  or  mesenteric  vessels  of  the  embryo,  by  which 
the  yolk  was  absorbed  into  its  body;  these  accompany  the  pedicle.  4.  The 
Urachus,  and  remains  of  the  Allantois.  5.  The  Vasa  Uuibilicalia  (n  n,  o),  which, 
in  the  later  period  of  gestation,  constitute  the  chief  part  of  the  Cord.  These 
last  vessels  consist  in  Man  of  two  arteries  and  one  vein.  The  arteries  are  the 
main  branches  of  the  Hypogastric ;  and  they  convey  to  the  placenta  the  blood 
which  has  to  be  aerated  and  otherwise  revivified,  by  being  brought  into  relation 
with  that  of  the  mother.  The  vein  returns  this  to  the  fcetus,  and  discharges  a 
part  of  it  into  Vena  Portse,  and  a  part  directly  through  the  Ductus  Venosus  into 
the  Vena  Cava 


792  OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 


PIG.  225. 


FIG.  226. 


Fig.  225. — Diagram  of  the  Circulation  in  the  Human  Embryo  and  its  Appendages,  as  seen 
in  profile  from  the  right  side,  at  the  commencement  of  the  formation  of  the  Placenta. 

Fig.  226. — The  same,  as  seen  from  the  front: — a,  venous  sinus,  receiving  all  the  systemic 
reins ;  b,  right  auricle ;  b',  left  auricle ;  c,  right  ventricle ;  c',  left  ventricle ;  d,  bulbus  aorticus, 
subdividing  into  e,  e',  e",  branchial  arches;  /,/',  arterial  trunks  formed  by  their  confluence; 
g,  g',  vena  azygos  superior;  h,  h',  confluence  of  the  superior  and  inferior  azygos  ;  j,  vena  cava 
inferior  ;  k,  k',  vena  azygos  inferior;  m,  descending  aorta;  «,  n,  umbilical  arteries  proceeding 
from  it;  o',  o,  umbilical  veins  :  q,  omphalo-mesenteric  vein;  r,  omphalo-rnesenteric  artery, 
distributed  on  the  walls  of  the  vitelline  vesicle  t;  v,  ductus  venosus;  y,  vitelline  duct; 
«,  chorion. 

895.  A  change  in  the  type  of  the  Circulating  system  of  the  foetus,  from  that 
at  first  presented  by  it  (§  892),  takes-place  at  a  very  early  period.  At  about  the 
4th  week,  in  the  Human  Embryo,  a  septum  begins  to  be  formed  in  the  ventricle ; 
and  by  the  end  of  the  8th  week,  it  is  complete.  The  septum  auricularum  is 
formed  at  a  somewhat  later  period,  and  it  remains  incomplete  during  the  whole 
of  ftetal  life ;  it  is  partly  closed  by  the  valvular  fold  covering  the  foramen  ovale, 
which  fold  is  developed  in  the  3rd  month.  During  the  same  period,  a  transfor- 
mation occurs  in  the  arrangement  of  the  Arterial  trunks  proceeding  from  the 
heart,  which  ends  in  their  assumption  of  the  form  they  present  until  the  end  of 
Foetal  life }  and  this  undergoes  but  a  slight  alteration,  when  the  plan  of  the  cir- 
culation is  changed  at  the  moment  of  the  first  inspiration.  The  number  of  aortic 
arches  on  each  side,  which  was  five  at  first,  soon  becomes  reduced  in  the  Mam- 
malia to  three,  by  the  obliteration  of  the  two  highest  pairs.  The  i  bulbus  aorti- 
cus '  is  subdivided,  by  the  adhesion  of  its  walls  at  opposite  points,  into  two  tubes, 
of  which  one  becomes  the  origin  of  the  Aorta  and  the  other  that  of  the  Pulmo- 
nary Artery;  and  of  the  three  pairs  of  (branchial)  arches,  the  highest,  being 
connected  with  the  aortic  trunk,  contributes  to  the  formation  of  the  Subclavian 
and  Carotid  arteries ;  whilst  of  the  middle  pair,  the  arch  on  the  right  side  is 
obliterated,  and  the  other  becomes  the  'arch  of  the  aorta.'  The  lowest  pair 
urises  from  the  Pulmonary  trunk,  and  forms  the  right  and  left  Pulmonary  arte- 
ries j  that  on  the  left  side,  however,  goes-on  to  join  the  descending  aorta  as 


ARTERIAL    AND    VENOUS    SYSTEMS    OF    EMBRYO.     793 

before,  and  thus  constitutes  the  Ductus  Arteriosus. — A  knowledge  of  these  dif- 
ferent stages  in  the  development  of  the  Heart  and  Arterial  system  enables  us  to 
explain  many  of  the  malformations  which  they  occasionally  present  in  Man  ; 
these  being  for  the  most  part  due  to  arrest  of  development,  whereby  the  circu- 
lating apparatus  is  permanently  fixed  in  conditions  that  are  properly  characteristic 
of  cold-blooded  animals.  And  it  is  interesting  to  remark,  too,  that  the  varieties 
which  not  unfrequently  present  themselves  in  the  arrangement  of  the  principal 
trunks  given-off  from  the  Aorta,  find  their  analogues  in  the  arrangement  that  are 
normally  characteristic  of  some  or  other  of  the  Mammalia.  (See  PRINC.  OP 
COMP.  PHYS.,  Am.  Ed.,  §§  262,  263). 

896.  The  Venotis  system  undergoes  changes  which  are  even  more  remarkable 
than  those  of  the  arterial  trunks.  In  its  earliest  condition,  it  has  been  ascer- 
tained by  Rathke  l  to  present  essentially  the  same  type  in  the  embryoes  of  all 
Vertebrated  animals  j  the  peculiarities  of  each  group  being  acquired  by  a  process 
of  subsequent  transformation.  There  is  at  first  a  pair  of  anterior  venous  trunks 
(Figs.  225,  226,  </,  #'),  receiving  the  blood  from  the  head,  and  a  pair  of  posterior 
trunks  (&,  &'),  formed  by  the  confluence  of  the  veins  of  the  trunk,  of  the  Wolf- 
fian  bodies,  &c. ;  the  former  are  persistent  as  the  jugular  veins ;  the  latter  remain 
separate  in  most  Fishes,  where  they  are  designated  the  cardinal  veins ;  but  in 
Man  (as  in  warm-blooded  Vertebrata  generally)  they  are  only  represented  by  the 
venae  azyyos,  major  and  minor,2  which  coalesce  into  a  common  trunk  for  a  con- 
siderable part  of  their  length.  One  of  the  anterior  trunks  and  one  of  the  poste- 
rior unite  on  either  side,  to  form  a  canal  which  is  known  as  the  Ductus  Cuvieri ; 
and  the  ducts  of  the  two  sides  coalesce  to  form  a  shorter  main  canal,  which  enters 
the  auricle,  at  that  time  an  undivided  cavity.  This  common  canal  is  absorbed 
into  the  auricle  at  an  early  period,  in  all  Vertebrata  above  Fishes ;  and  after  the 
septum  auricularum  is  formed,  the  two  Cuvierian  ducts  separately  enter  the  right 
auricle.  This  arrangement  is  persistent  in  Birds  and  the  inferior  Mammals,  in 
which  we  find  two  Venae  Cavse  superiores,  entering  the  right  auricle  separately  j 
but  in  the  higher  Mammalia  and  in  Man,  the  left  duct  is  obliterated,  and  the 
right  alone  remains  as  the  single  Vena  Cava  superior,  a  transverse  communica- 
ting branch  being  formed,  to  bring  to  it  the  blood  of  the  left  side.3  The  double 
Vena  Cava  sometimes  presents  itself  as  a  monstrosity  in  the  Human  subject. 
As  the  anterior  extremities  are  developed,  the  subclavian  veins  are  formed  to 
return  the  blood  from  them ;  and  these  discharge  themselves  into  the  jugulars. 
The  Omphalo-Mesenteric  vein  (Fig.  225,  q),  which  is  another  primitive  trunk 
common  to  all  Vertebrata  (§  891),  is  formed  by  the  confluence  of  the  veins  of 
the  yolk-bag  and  intestinal  canal,  and  passes  by  itself,  with  the  two  Cuvierian 
ducts,  into  the  auricle.  The  upper  part  of  this  remains  to  constitute  the  upper 
part  of  the  Inferior  Cava  (Figs.  225,  226,^'),  the  lower  portion  of  which  arises 
between  the  Wolffian  bodies,  and  originally  enters  the  omphalo-mesenteric  vein 
above  the  liver.  When  the  liver  is  formed,  the  omphalo-mesenteric  vein  becomes 
connected  with  it,  both  by  afferent  and  by  efferent  trunks,  the  former  remaining 
as  the  Vena  Portse,  and  the  latter  as  the  Hepatic  vein  •  and  after  giving^off  the 
former  trunks,  the  omphalo-mesenteric  vein  is  itself  obliterated,  so  that  all  the 
blood  which  it  conveys  passes  through  the  liver.  The  Inferior  Cava,  which  re- 
ceives the  hepatic  vein,  is  gradually  enlarged  by  the  reception  of  most  of  the 
veins  from  the  inferior  part  of  the  trunk  and  the  lower  extremities,  and  the  vena 
azygus  is  reduced  in  the  same  proportion  j  in  some  rare  cases  of  abnormal  forma- 
tion, however,  the  vena  cava  fails  to  be  developed,  and  then  the  blood  from  the 

1  "  Ueber  den  Bau  und  die  Entwickelung  des  Venensystems  der  Wirbelthiere,"  1838 

2  See  Muller's  "  Vergleicheride  Anatomie  der  Myxinoiden,"  Berlin,  1840. 

3  See  the  elaborate  Memoir  '  On  the  Development  of  the  Great  Anterior  Veins  in  Mau 
and  Mammalia'  ("Phil.  Trans.,"  1850),  by  Mr.  J.  Marshall;  who  has  further  shown  that 
gome  vestiges  of  the  original  arrangement  may  be  traced  even  in  the  normal  condition  of 
the  venous  system  in  the  adult. 


794  Or  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

FIG.  227. 

O     O 


Diagram  of  the  Foetal  Circulation  :  —  1.  The  umbilical  cord,  consisting  of  the  umbilical 
vein  and  two  umbilical  arteries,  proceeding  from  the  placenta  (2).  3.  The  umbilical  vein 
dividing  into  three  branches ;  two  (4,  4)  to  be  distributed  to  the  liver,  and  one  (5),  the  ductus 
venosus,  which  enters  the  inferior  vena  cava  (6).  7.  The  portal  vein,  returning  the  blood 
from  the  intestines,  and  uniting  with  the  right  hepatic  branch.  8.  The  right  auricle;  the 
course  of  the  blood  is  denoted  by  the  arrow  proceeding  from  8  to  9,  the  left  auricle.  10.  The 
left  ventricle;  the  blood  following  the  arrow  to  the  arch  of  the  aorta  (11),  to  be  distributed 
through  the  branches  given-off  by  the  arch  to  the  head  and  upper  extremities.  The  arrows 
12  and  13,  represent  the  return  of  the  blood  from  the  head  and  upper  extremities  through 
the  jugular  and  subclavian  veins,  to  the  superior  vena  cava  (14),  to  the  right  auricle  (8),  and 
in  the  course  of  the  arrow  through  the  right  ventricle  (15),  to  the  pulmonary  artery  (16). 
.17.  The  ductus  arteriosus,  which  appears  to  be  a  proper  continuation  of  the  pulmonary 
artery;  the  offsets  at  each  side  are  the  right  and  left  pulmonary  arteries  cut  off.  The  ductus 
arteriosus  joins  the  descending  aorta  (18, 18),  which  divides  into  the  common  iliacs,  and  these 
into  the  internal  iliac,  which  become  the  umbilical  arteries  (19)  and  return  the  blood  along 
the  umbilical  cord  to  the  placenta,  and  the  external  iliacs  (20),  which  are  continued  into  the 
lower  extremities.  The  arrows  at  the  termination  of  these  vessels  mark  the  return  of  the 
venous  blood  by  the  veins  to  the  inferior  cava. 

lower  parts  of  the  body  is  conveyed  to  the  superior  cava  through  the  system  of 
the  vena  azygos.  The  Umbilical  Vein,  which,  like  the  other  great  venous  trunks, 
is  at  first  double  (Figs.  225,  226,  o,  o'),  is  to  be  regarded  as  a  product  of  the 
combination  of  the  veins  of  the  allantois  with  an  anterior  vein  of  the  abdominal 
parietes;  it  being  probably  through  this  latter  channel  that  it,  comes  to  discharge 
itself  into  the  vena  portse,  which  lies  in  a  part  of  the  body  very  distant  from  that 
at  which  the  allantois  was  developed.  As  the  omphalo-mesenteric  vein  dinii- 


COURSE     OF    THE     CIRC  TL  AT  ION    IN    THE     F(ETUS.      795 

n  shes  in  size,  the  umbilical  veins  increase,  and  coalesce  into  a  single  trunk; 
this  then  becomes  the  chief  source  of  supply  to  the  vena  portse,  also  forming  an 
anastomosis  with  the  inferior  cava,  which  constitutes  the  Ductus  Venosus. 

897.  The  following  is  the  course  of  the  Circulation  in  the  mature  Foetus.  — 
The  fluid  brought  from  the  Placenta  by  the  umbilical  vein,  is  partly  conveyed  at 
once  to  the  ascending  Cava  by  means  of  the  ductus  venosus,  but  chiefly  flows 
through  the  vena  portse  into  the  Liver,  whence  it  reaches  the  ascending  Cava  by 
the  hepaiic  vein.     Having  thus  been  transmitted  through  the  great  depurating 
organ,  the  Placenta,  and  the  great  assimilating  organ,  the  Liver,1  it  is  in  the  con- 
dition of  arterial  blood ;  but,  being  mixed  in  the  great  vessels  with  that  which 
has  been  returned  from  the  trunk  and  lower  extremities,  it  loses  this  character  in 
some  degree,  by  the  time  that  it  arrives  at  the  Heart.     In  the  right  auricle, 
which  it  then  enters,  it  would  be  also  mixed  with   the  venous  blood  brought 
thither  by  the  descending  Cava;  were  it  not  that  a  very  curious  provision  exists, 
to   prevent   (in   great   degree,  if  not  entirely)  any  such   further  dilution.     The 
Eustachian  valve  has  been  found,  by  the  experiments  of  Dr.  J.  Reid,2  to  serve 
tbe  purpose  of  directing  the  arterial  blood,  which  flows  upwards  from  the  ascend- 
iny  Cava,  through  the  foramen  ovale,  into  the  left  auricle,  whence  it  passes  into 
the  left  ventricle ;  whilst  it  also  directs  the  venous  blood,  that  has  been  returned 
by  the  descending  Cava,  into  the  right  ventricle.     When  the  ventricles  contract, 
the  arterial  blood  which  the  left  contains  is  propelled  into  the  ascending  Aorta, 
and  supplies  the  branches  that  proceed  to  the  head  and  upper  extremities,  before 
it  undergoes  any  admixture;  whilst  of  the  venous  blood  contained  in  the  right 
ventricle,  part  is  transmitted  by  the  Pulmonary  artery  to  the  lungs,  but  another 
(and  probably  by  far  the  larger)  part  finds  its  way  through  the  Ductus  Arteriosus 
into  the  descending  Aorta,  mingling  with  the  arterial  current  which  that  vessel 
previously  conveyed,  and  passing  thus  to  the  trunk  and  lower  extremities.     Hence 
the  head  and  superior  extremities,  whose  development  is  required  to  be  in  advance 
of  that  of  the  lower,  are  supplied  with  blood  nearly  as  pure  as  that  which  returns 
from  the  placenta;  whilst  the  rest  of  the  body  receives  a  mixture  of  this  with 
what  has  previously  circulated  through  the  system  ;  and  of  this  mixture  a  por- 
tion is  transmitted  to  the  placenta,  to  be  renovated  by  coming  into  relation  with 
the  maternal  fluid.  —  At  birth,  the  course  of  the  current  is  entirely  changed  by 
the  cessation  of  the  circulation  through  the  Placenta,  and  by  the  enormous  in- 
crease in  the  quantity  transmitted  to  the  Lungs,  which  takes-place  immediately 
on  the  first  inspiration  :  the  Ductus  Venosus  and  Ductus  Arteriosus  soon  shrivel 
into  ligaments;  the  Foramen  Ovale  becomes  closed  by  its  valve;  and  the  circu- 
lation, which  was  before  carried-on  upon  the  plan  of  that  of  the  higher  Reptiles, 
now  becomes  that  of  the  complete  Bird  or  Mammal.3     It  is  by  no  means  unfre- 
quent,  however,  for  some  arrest  of  development  to  prevent  the  completion  of 
these  changes ;  and  various  malformations,  involving  an  imperfect  discharge  of 
the  function,  may  hence  result. 

898.  The  Alimentary  Canal  has  been  shown  (§  889)  to  have  its  origin  in  the 

*  It  does  not  seem  probable  that  the  depurating  action  of  the  Liver  can  be  energetically 
performed  during  foetal  life;  and  its  large  dimensions  and  copious  supply  of  blood  appear 
rather  to  be  referable  to  its  function  as  a  blood-making  gland  (g  132). 

3  "Edinb.  Med.  and  Surg.  Journal,"  vol.  xliii;  and  "Anat.,  Physiol.,  and  Pathol.  Re- 
searches," Chap.  ix. 

3  It  has  been  argued  by  Dr.  Peaslee  (of  Dartmouth  College,  U.  S.),  that  the  above 
account  is  incorrect,  since  the  diameter  of  the  Ductus  Arteriosus  is  so  small  in  proportion 
to  that  of  the  Pulmonary  arteries,  that  it  can  serve  no  other  purpose  than  that  of  a  '  waste- 
pipe  '  to  carry-off  the  superfluous  blood  which  they  cannot  receive.  But  he  supposes  the 
amount  of  blood  transmitted  through  these  vessels  respectively,  to  be  chiefly  or  entirely 
determined  by  their  respective  diameters ;  and  takes  no  account  of  the  numerous  facts 
which  prove  that  the  quantity  of  blood  transmitted  to  the  lung?  before  birth,  is  extremely 
»mall  in  proportion  to  that  which  they  receive  so  soon  as  the  respiratory  function  is  fully 
established.  See  his  'Monograph  on  the  Foetal  Circulation,'  in  "American  Medical 
Monthly,"  May,  1854. 


796    OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

blastodermic  vesicle ;  being  a  portion  pinched-off  (as  it  were)  from  that  part  of 
it  which  is  just  beneath  the  spinal  column  of  the  embryo,  whilst  the  remainder, 
which  is  at  tha.t  time  the  largest  part  of  it,  forms  the  vitelline  or  umbilical  vesi 
cle.  In  its  earliest  form,  it  is  merely  a  long  narrow  tube  (jFig.  228,  m),  nearly 

FIG.  228. 


Embryo  of  Dog,  25  days  after  last  copulation  : — a,  a,  nostrils ;  b,  b,  eyes ,:  c.  c,  first  visce- 
ral arches,  forming  the  lower  jaw;  d,  d,  second  visceral  arches  ;  e,  right  auricle;  /,  left  auri- 
cle; g,  right  ventricle;  h,  left  ventricle;  i,  aortic  bulb;  k,  k,  liver,  between  the  two  lobes  of 
•which  is  seen  the  divided  orifice  of  the  omphalo-mesenteric  vein;  I,  stomach;  m,  intestine, 
communicating  with  the  umbilical  vesicle  nn;  o,  o,  corpora  Wolffiana ;  p,  allantois ;  q,  q,  an- 
terior extremities  ;  r,  r,  posterior  extremities. 

straight,  and  communicating  with  the  umbilical  vesicle  (w,  n)  at  about  the  middle 
of  its  length  j  thus  it  may  be  regarded  as  composed  of  the  union  of  two  divi- 
sions, an  upper  and  a  lower.  At  first,  neither  mouth  nor  anus  exists ;  but  these 
are  formed  early  in  the  second  month,  if  not  before.  The  tube  gradually  mani- 
fests a  distinction  into  its  special  parts,  oesophagus,  stomach,  small  intestine,  and 
large  intestine;  and  the  first  change  in  its  position  occurs  in  the  stomach,  which, 
originally  disposed  in  the  line  of  the  body,  afterwards  takes  an  oblique  direction. 
The  curves  of  the  large  and  small  intestine  present  themselves  at  a  later  period. 
It  is  at  the  lower  part  of  the  small  intestine,  near  its  termination  in  the  large, 
that  th'e  entrance  of  the  vitelline  duct  persists ;  and  a  remnant  of  this  canal  is 
not  unfrequently  preserved  throughout  life;  in  the  form  of  a  small  pouch  or 
diverticulum  from  that  part  of  the  intestine. 

899.  In  immediate  connection  with  the  intestinal  tube,  we  find  the  first  rudi- 
ment of  the  Liver,  which  is  formed  by  the  thickening  of  the  cells  in  the  wall  of 
the  canal,  at  the  spot  at  which  the  hepatic  duct  is  subsequently  to  discharge  itself. 
This  thickening  increases,  so  as  to  form  a  projection  upon  the  exterior  of  the 
canal ;  and  soon  afterwards  the  lining  membrane  of  the  intestine  dips-down  into 
<t,  so  that  a  kind  of  caecum  is  formed,  surrounded  by  a  mass  of  cells,  as  shown 


DEVELOPMENT  OF  THE  LIVER. 


797 


in  Fig.  229.     The  increase  of  the  organ  seems  to  take-place  by  a  continual  new 

budding-forth  of  cells  from  its  peripheral 

portion  ;  and  a  considerable  mass  is  thus  FIG.  229. 

formed,  before  the  caecum  in  its  interior 

undergoes  any  extension  by  ramifications 

into  it.     Gradually,  however,  the  cells  of 

the  exterior  become  metamorphosed  into 

fibrous    tissue  for  the  investment  of  the 

organ  ;    those  of  the    interior  break-down 

into  ducts,  which    are    developed   in  con- 

tinuity with  the  caecum  derived  from  the 

intestine,  and  which  are  lined  by  muscular 

and    fibrous    tissues    developed    from    the 

primitive  cellular  blastema;  whilst  those  .  Origin  of  the  ^>e,  from  the  intestinal  wall, 
r  ,  .  ,  ,  i  ,  in  the  embryo  ot  the  I1  owl.  on  the  iourth  day 

which  occupy  the  intervening  space,  and  of  incubation  ;_a,   heart;    b,  intestine;  c, 
which    form   the   bulk   of  the   gland,   give  everted  portion  giving  origin  to  liver  j  d,  li- 
origin   to  the  proper  secreting  cells,  which  verj  e,  portion  of  vitelline  vesicle. 
are  now  to  come  into  active  operation.    As 

this  is  going-on,  the  hepatic  mass  is  gradually  removed  to  a  distance  from  the  wall 
of  the  alimentary  canal;  and  the  caecum  is  narrowed  and  lengthened,  so  as  to  be- 
come a  mere  connecting  pedicle,  forming,  in  fact,  the  main  trunk  of  the  hepatic 
duct.  —  In  the  Human  embryo,  the  formation  of  the  Liver  begins  at  about  the 
third  week  of  intra-uterine  existence;  the  organ  is  from  the  first  of  very  large 
size,  when  compared  with  that  of  the  body;  and  between  the  third  and  the  fifth 
weeks,  it  is  one-half  the  weight  of  the  entire  embryo.  It  is  at  that  period 
divided  into  several  lobes.  By  the  third  lunar  month,  the  liver  extends  nearly 
to  the  pelvis,  and  almost  fills  the  abdomen  ;  the  right  side  now  begins  to  gain 
upon  the  left;  the  gall-bladder  makes  its  first  appearance  at  this  time.  The  sub- 
sequent changes  chiefly  consist  in  the  consolidation  of  the  viscus,  and  the  diminu- 
tion of  its  proportional  size.  Up  to  the  period  of  birth,  however,  the  bulk  of 
the  liver,  relatively  to  that  of  the  entire  body,  is  much  greater  than  in  the  adult; 
the  proportion  being  as  1  to  18  or  20  in  the  new-born  child,  whilst  it  is  about  1 
to  36  in  the  adult;  and  the  difference  between  the  right  and  left  lobes  is  still 
inconsiderable.  During  the  first  year  of  extra-uterine  life,  however,  a  great 
change  takes  place  ;  the  right  lobe  increases  a  little  or  remains  stationary,  whilst 
the  left  lobe  undergoes  an  absolute  diminution,  being  reduced  nearly  one-half; 
and  as,  during  the  same  period,  the  bulk  of  the  rest  of  the  body  has  been  rapidly 
increasing,  the  proportion  is  much  more  reduced  during  that  period,  than  in  any 
subsequent  one  of  the  same  length.  According  to  Meckel,  the  liver  of  the 
newly-born  infant  weighs  one-fourth  heavier  than  that  of  a  child  of  eight  or  ten 
months  old  ;  and  as  the  weight  of  the  whole  body  is  more  than  doubled  during 
the  same  time,  it  is  obvious  that  the  change  in  the  proportion  of  the  two  must 
be  principally  effected  at  this  epoch.  The  liver  seems  to  be  engaged,  during 
foetal  life,  in  the  depuration  of  the  blood  (as  appears  from  the  accumulation  of 
meconium,  which  is  chiefly  altered  bile,  in  the  intestinal  canal  at  birth);  but  at 
the  same  time  it  is  serving  as  a  blood-making  organ  (§§  182,  167),  and  this  is 
probably  its  principal  function  before  birth. 

900.  The  general  history  which  has  just  been  given  of  the  dcvelopment'of  the 
Liver,  seems  equally  applicable  to  the  other  glands  that  are  evolved  from  the 
parietes  of  the  Alimentary  canal,  such  as  the  Salivary  glands  and  Pancreas; 
since  they  all  seem  to  commence  in  little  masses  of  cells,  formed  by  an  increased 
development,  at  certain  spots,  of  the  layer  of  blastema  which  originally  consti- 
tutes its  wall;  and  whilst  some  of  these  cells  give  origin  to  the  proper  vesicles 
of  each  gland,  others  form  its  ducts  and  tubuli  by  their  deliquescence.  —  The  de 
velopment  of  the  Spleen  and  of  the  Supra-Renal,  Thymus,  and  Thyroid  bodies, 
has  been  already  described  (§§  143-147). 


798    OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

901.  The  Lungs  are  also  developed  in  immediate  relation  with  the  upper  part 
of  the  Alimentary  canal,  their  first  rudiments  shooting-forth  as  a  pair  of  bud-like 

processes  (Fig.  230,  o)  from  its  oesopha- 

FIG.  230.  geal  portion.     These  were    originally  de- 

scribed by  Von  Barr  as  hollow,   and  as 
being  in  reality  diverticula  from  the  tube 
itself.     But  most  later  observers  agree  in 
stating  that  the  bud-like  processes  are  not 
at  first  hollow,  but  are  solid  aggregations 
of  cells,  formed  by  a  multiplication  of  the 
cells  constituting  the  external  wall  of  the 
First  appearance  of  the  Lungs :— a,  in  a  alimentary  tube,  into  which    its    internal 
Fowl  at  four  days;  6,  in  a  Fowl  at  six  days;  tuni(J   jg    not  prolonged.      These  gradually 
£  termination   of  bronchus  in  a  very  young  .^^   ^   ^  extending  down*ards   ^ 

the  multiplication  of  their  component  cells 

in  that  direction ;  and  cavities  are  formed  in  them  (probably,  as  in  the  preceding 
instances,  by  the  deliquescence  or  fusion  of  some  of  the  ceils  of  their  interior), 
which  at  first  communicate  with  the  pharynx  by  separate  apertures ;  these,  how- 
ever, coalesce  into  one,  as  the  channels  are  elongated  into  tubes,  and  the  pulmo- 
nary organs  are  removed  to  a  distance  from  their  point  of  exit. — The  first  appear- 
ance of  the  Lungs,  in  the  Human  embryo,  takes-place  at  about  the  6th  week,  at 
which  time  they  are  simple  elevations  of  the  external  layer  of  the  cesophageal 
wall;  from  this,  however,  they  are  soon  removed;  each  rudimentary  lung  hav- 
ing its  own  bronchial  tube,  connecting  it  with  a  trachea  common  to  both  (Fig. 
230,  ft).  Their  surface  becomes  studded  with  numerous  little  wart-like  projec- 
tions, which  are  caused  by  the  formation  of  corresponding  enlargements  of  their 
cavity;  these  enlargements  soon  become  prolonged,  and  develope  corresponding 
bud-like  enlargements  from  their  sides;  and  in  this  manner,  the  form  of  the 
organs  is  gradually  changed,  a  progressive  increase  in  their  bulk  taking-place 
from  above  downwards,  in  consequence  of  the  extension  of  the  bronchial  ramifi- 
cations of  the  single  tube  at  the  apex.  At  the  same  time,  however,  a  corres- 
ponding increase  in  the  amount  of  the  parenchymatous  tissue  of  the  lung  is 
taking-place;  for  this  is  deposited  in  all  the  interstices  between  the  bronchial 
ramifications,  and  might  be  compared  with  the  soil  filling-up  the  spaces  amongst 
the  roots  of  a  tree.  It  is  in  this  parenchyma  that  the  pulmonary  vessels  are  dis- 
tributed ;  and  the  portion  of  it  which  extends  beyond  the  terminations  of  the 
bronchial  tubes,  seems  to  act  as  the  nidus  for  their  further  extension.  It  can  be 
easily  shown  that,  up  to  a  late  period  of  the  development  of  the  lungs,  the 
dilated  terminations  of  the  bronchi  constitute  the  only  air-cells  (Fig  230,  c); 
but,  as  already  mentioned,  the  parenchyma  subsequently  has  additional  cavities 
formed  within  it. — It  is  a  fact  of  some  interest,  as  an  example  of  the  tendency 
of  certain  diseased  conditions  to  produce  a  return  to  forms  which  are  natural  to 
the  foetal  organism,  or  which  present  themselves  in  other  animals,  that  up  to  a 
late  period  in  the  development  of  the  Human  embryo,  the  lungs  do  not  nearly 
fill  the  cavity  of  the  chest,  and  the  pleura  of  each  side  contains  a  good  deal  of 
serous  fluid. 

902.  The  embryological  development  of  the  Urinary  organs  in  Vertebrated 
animals  is  a  subject  of  peculiar  interest;  owing  to  the  correspondence  which  may 
be  traced  between  the  transitory  forms  they  present  in  the  higher  classes,  and 
their  permanent  condition  in  the  lower.  In  this  respect,  there  is  an  evident 
analogy  with  the  Respiratory  system.  The  first  appearance  of  anything  resem- 
bling a  Urinary  apparatus  in  the  Chick,  is  seen  on  the  second-half  of  the  third 
day.  The  form  at  that  time  presented  by  it,  is  that  of  a  Jong  canal,  extending 
on  each  side  of  the  spinal  column,  from  the  region  of  the  heart,  towards  the  allan- 
tois  (Fig.  228,  o,  o] ;  on  the  sides  of  this  are  a  series  of  elevations  and  depres- 
sions, indicative  of  the  incipient  development  of  caeca.  On  the  4th  day,  the 


DEVELOPMENT    OF    THE    URINARY    ORGANS, 


799 


Fm.  231. 


State    of  the    Urinary    and 


Corpora  Wolffiana,  as  they  are  then  termed,  are  distinctly  recognized  as  com- 
posed of  a  series  of  caecal  appendages,  which  are  attached  along  the  whole 
course  of  the  first-mentioned  canal,  opening  into  its 
outer  side  (Fig.  231,  l).  On  the  5th  day  these 
appendages  are  convoluted,  and  the  body  which 
they  form  acquires  increased  breadth  and  thickness; 
they  evidently  then  possess  a  secreting  function,  and 
the  fluid  which  they  separate  is  poured  by  their  long 
straight  canals  (2,  2)  into  the  cloaca;  and  between 
their  component  shut  sacs,  numbers  of  small  points 
appear,  which  consist  of  little  clusters  of  convoluted 
vessels,  exactly  analogous  to  the  Corpora  Malpighiana 
of  the  true  kidney.  These  bodies  remain  as  the  per- 
manent urinary  organs  of  Fishes;  but  in  the  higher 
Vertebrata  they  give  place  to  the  true  Kidneys,  the 
development  of  which  commences  in  the  Chick  about 
the  6th 'day.  These  when  first  seen,  are  lobulated 
greyish  masses  (3),  which  seem  to  sprout  from  the 
outer  edges  of  the  Wolffian  bodies,  but  which  are 

really  independent  formations,  springing  from  a  mass  Genital  Apparatus  in  the  early 
of  blastema  behind  them  ;  and  as  they  gradually  in-  ^.Jj*,^*^* 
crease  in  size  and  advance  in  development,  the  VVolman  cretory  ducts;  3,  kidneys;  4, 
bodies  retrograde ;  so  that  at  the  end  of  foetal  life,  the  ureter;  5,  5,  testes. 
onlv  vestige  of  them  is  to  be  found  as  a  shrunk  rudiment, 

situated  (in  the  male)  near  the  testes,  to  which  their  excretory  ducts  serve  as  the 
outlets,  becoming  the  l  vasa  deferential — The  history  of  the  development  of  the  Uri- 
nary organs  in  the  Human  embryo,  seems  to  correspond  closely  with  the  foregoing 
The  W olfiian  bodies  begin  to  appear  towards  the  end  of  the  first  month ;  and  it  is 
in  the  course  of  the  7th  week,  that  the  true  Kidneys  first  present  themselves. 
When  at  their  greatest  development,  the  Corpora  Wolffiana  are  the  most  vascular 
parts  of  the  body  next  to  the  liver;  four  or  five  branches  from  the  aorta  are  dis- 
tributed to  each,  and  two  veins  are  returned  from  each  to  the  vena  cava.  The 
upper  arteries  arid  their  corresponding  veins  are  afterwards  converted  into  the 
Renal  or  emulgent  vessels ;  and  the  lower  into  the  Spermatic  vessels.  From  the 
beginning  of  the  3d  month,  a  diminution  takes-place  in  the  size  of  the  Wolfnau 
bodies,  pari  passu  with  the  increase  of  the  Kidneys;  and  at  the  time  of  birth, 
scarcely  any  traces  of  the  former  can  be  found.  At  the  end  of  the  3d  month, 
the  Kidneys  consist  of  seven  or  eight  lobes,  the  future  pyramids ;  their  excretory 
ducts  still  terminate  in  the  canal,  the  sinus  uroyenilalis,  which  receives  those  of 
the  Wolffian  bodies  (subsequently  to  become  the  vasa  deferentia),  and  of  the 
Fallopian  tubes; '  and  this  opens,  with  the  rectum,  into  a  sort  of  Cloaca,  analo- 
gous to  that  which  is  permanent  in  the  oviparous  Vertebrata.  The  Kidneys  are 
at  this  time  covered  by  the  Supra-Renal  capsules,  which  equal  them  in  size , 
about  the  6th  month,  however,  these  have  decreased,  whilst  the  kidneys  have 
increased,  so  that  their  proportional  weight  is  as  1  to  2J.  At  birth,  the  weight 
of  the  Kidneys  is  about  three  times  that  of  the  Supra-Renal  capsules,  and  they 
bear  to  the  whole  body  the  proportion  of  1  to  80 ;  in  the  adult,  however,  they  are 
no  more  than  1  to  240.  The  lobulated  appearance  of  the  kidney  gradually  disap- 
pears; partly  in  consequence  of  the  condensation  of  the  areolar  tissue  which  con- 

1  Although  it  has  been  usually  considered  that  the  Vasa  Deferentia  of  the  male  and  the 
Fallopian  tubes  of  the  female,  are  homologous  organs,  yet  this  does  not  seem  really  to  bo 
the  case ;  for  the  former  are  derived  from  the  excretory  ducts  of  the  Wolffian  bodies, 
whilst  the  latter  are  independent  formations,  which  are  found  to  co-exist  with  seminal 
ducts  at  an  early  period  of  development,  alike  in  male  and  in  female  embryoes.  (See  Ko- 
belt,  "Der  Nebeneirstock  des  Weibes."  Heidelberg,  1847.)  The  ducts  of  the  Wolffian 
bodies,  although  subsequently  disappearing  in  the  females  of  most  Mammals,  remain  per- 
manent as  '  Gaertners  canals'  in  the  female  Ruminants  and  Pig. 


800  OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

nects  its  different  portions,  and  partly  through  the  development  of  additional 
tubuli  in  the  interstices. — The  Urinary  Bladder  is  formed  quite  independently  of 
the  secreting  apparatus,  being  an  enlargement  of  a  portion  of  the  pars  urinaria 
of  the  '  uro-genital  sinus '  (§  904). 

903.  The  essential  parts  of  the  Generative  Apparatus,  namely  the  Testes  in 
the  male,  and  the  Ovaria  in  the  female,  are  first  developed  in  such  immediate 
proximity  with  the  Corpora  Wolffiana  (Fig.  231,  5,  5),  that  they  have  been  sup- 
posed to  sprout-forth  from  them;  this,  however,  is  not  really  the  case,  as  they 
have  an  independent  origin  in  a  mass  of  blastema  peculiar  to  themselves.  They 
make  their  first  appearance  in  the  Chick,  as  delicate  striae  on  the  Wolffian  bodies, 
about  the  fourth  day ;  at  which  period  no  difference  can  be  detected  between  the 
Testes  and  the  Ovaria,  which  originate  in  precisely  the  same  manner.  In  the 
Human  embryo,  the  rudiments  of  the  sexual  organs, — whether  testes  or  ovaria, — 
first  present  themselves  soon  after  the  kidneys  make  their  appearance,  that  is, 
towards  the  end  of  the  7th  week.  They  are  originally  much  prolonged,  and 
seem  to  consist  of  a  kind  of  soft,  homogeneous  blastema,  in  which  the  structure 
characteristic  of  each  organ  subsequently  developes  itself.  The  Testis  gradu- 
ally assumes  its  permanent  form  ;  the  epididymis  appears  in  the  tenth  week  ;  and 
the  gubernaculum  (a  membranous  process  from  the  filamentous  tissue  of  the  scro- 
tum, analogous  to  the  round  ligament  arising  from  the  labium  and  attached  to 
the  ovary  of  the  female),  which  is  originally  attached  to  the  vas  deferens,  gradu- 
ally fixes  itself  to  the  lower  end  of  the  testis  or  epididymis.  The  Testes  begin  to 
descend  at  about  the  middle  period  of  pregnancy ;  at  the  seventh  month  they 
reach  the  inner  ring;  in  the  eighth  they  enter  the  passage  ;  and  in  the  ninth  they 
usually  descend  into  the  scrotum.  The  cause  of  this  descent  is  not  very  clear;  it 
can  scarcely  be  due  merely,  as  some  have  supposed,  to  the  contraction  of  the 
gubernaculum ;  since  that  does  not  contain  any  fibrous  structure,  until  after  the 
lowering  of  the  testes  has  commenced.  It  is  well  known  that  the  testes  are  not 
always  found  in  the  scrotum  at  the  time  of  birth,  even  at  the  full  period.  Upon 
an  examination  of  97  new  born  infants,  Wrisberg  found  both  testes  in  the  scro- 
tum in  67,  one  or  both  in  the  canal  in  17,  in  8  one  testis  in  the  abdomen,  and  in 
3  both  testes  within  the  cavity.  Sometimes  one  or  both  testes  remain  in  the 
abdomen  during  the  whole  of  life;  but  this  circumstance  does  not  seem  to  impair 
their  function.1  This  condition  is  natural,  indeed,  in  the  Ram. — The  Ovary 
undergoes  much  less  alteration,  either  in  its  intimate  structure,  or  in  its  position. 
Its  efferent  canal  (which,  as  just  stated,  is  not  the  representative  of  the  vas  de- 
ferens of  the  male)  remains  detached  from  it,  having  a  free  terminal  aperture, 
and  thus  constituting  the  Fallopian  tube.  The  Uterus  (which  was  formerly  sup- 
posed to  be  formed  by  the  coalescence  of  the  Fallopian  tubes),  is  now  known  to 
be  derived,  like  the  Vagina,  from  the  genital  portion  of  the  *  uro-genital  sinus ' 
(§  904),  which  is  formed  exactly  on  the  same  plan  in  both  sexes  alike,  at  an 
early  period  of  foetal  development,  and  receives  at  its  upper  extremity  the  termi- 
nations of  the  Fallopian  tubes.  In  the  Female,  this  canal  increases  in  size ;  and 
a  marked  separation  is  established  between  its  lower  or  vaginal  portion  and  its 
upper  or  uterine  portion.  The  former  opens  into  the  undivided  portion  of  the 
uro-genital  sinus,  which  also  receives  the  terminations  of  the  urethra  and  of  the 
Wolman  ducts,  and  which  remains  permanently  unclosed.  In  the  Male,  on  the 
other  hand,  the  sinus  genitalis  makes  no  advance  in  development,  and  diminishes 
in  relative  size ;  so  that  at  the  period  of  foetal  maturity,  it  is  only  discoverable  aa 
the  vesicula  prostatica,  which  has  been  supposed  until  recently  to  be  an  appen- 
dage to  the  prostate  gland.  A  transverse  constriction  in  this  canal  marks-out  its 
vaginal  from  its  uterine  portion ;  the  former  having  exactly  the  same  relation  as 
in  the  female  to  the  terminations  of  the  urethra  and  of  the  Wolman  ducts  (vasa 
deferentia)  in  the  '  uro-genital  sinus,5  which  is  subsequently  closed-in,  however^ 

1  A  case  has  Lately  occurredwithin  the  Author's  knowledge  ill  which  both  testes  remained 
hi  the  abdomen  until  the  tenth  year,  and  then  descended. 


DEVELOPMENT  OF  TESTES  AND  OVARIA. 


801 


so  as  apparently  to  form  a  continuation  of  the  urethral  canal ;  and  the  latter,  in 
those  Mammals  whose  females  have  a  f  uterus  bicornis/  exhibiting  a  like  divari- 
cation into  two  lateral  halves.1 

904.  The  history  of  the  development  of  the  external  Organs  of  Generation  in 
the  two  sexes,  presents  matter  of  great  interest,  from  the  light  which  is  thrown 
by  a  knowledge  of  it  upon  the  malformations  of  these  organs,  which  are  among 
the  most  common  of  all  departures  from  the  normal  type  of  Human  organization. 
— Not  only  is  the  distinction  of  sexes  altogether  wanting  at  first ;  but  the  con- 
formation of  the  external  parts  of  the  apparatus  is  originally  the  same  in  Man 
and  the  higher  Mammalia,  as  it  permanently  is  in  the  Oviparous  Vertebrata. 
For,  about  the  5th  or  6th  week  of  embryonic  life,  the  opening  of  a  cloaca  may  be 
seen,  externally,  which  receives  the  termination  of  the  intestinal  canal,  the  ure- 
ters, and  the  efferent  ducts  of  the  sexual  organs;  but  at  the  10th  or  llth  week, 

FIG.  232. 


Urinary  and  Generative  Organs  of  a  Human  Embryo  measuring  3£  inches  in  length.  A. 
General  view  of  these  parts :  1,  suprarenal  capsules ;  2,  kidneys;  3,  ovary  j  4,  Fallopian  tube ; 
5,  uterus ;  6,  intestine;  7,  the  bladder.  B.  Bladder  and  generative  organs  of  the  same  embryo 
viewed  from  the  side:  1,  the  urinary  bladder;  2,  urethra;  3,  uterus  (with  two  cornua);  4, 
vagina;  5,  part  as  yet  common  to  the  vagina  and  urethra;  6,  common  orifice  of  the  urinary 
and  generative  organs ;  7,  the  clitoris,  c.  Internal  generative  organs  of  the  same  embryo : 
1,  the  uterus ;  2,  the  round  ligaments ;  3,  the  Fallopian  tubes ;  4,  the  ovaries ;  5,  the  remains 
of  the  Wolffian  bodies,  n.  External  generative  organs  of  the  same  embryo :  1,  the  labia  ma- 
jora;  2,  the  nymphse;  3,  the  clitoris.  After  Miiller. 

the  anal  aperture  is  separated  from  that  of  the  genito-urinary  canal  or  <  uro-geni- 
tal  sinus/  by  the  development  of  a  transverse  band  j  and  the  uro-genital  sinus 
itself  is  gradually  separated  by  a  like  process  of  division,  into  a  '  pars  urinaria ' 

1  See  Prof.  E.  Weber's  "  Zusatze  zur  Lehre  vom  Baue  und  den  Verriehtungen  der  Gesch- 
lechtsorgane,"  Leipzig,  1846;  and  Dr.  Leuckart's  Art.  'Vesicula  Prostatica'  in  "Cyclop 
of  Anat.  and  Phosiol.,"  vol.  iv. — It  was  supposed  by  Prof.  Weber,  that  the  vesicula  pros- 
tatica  is  the  homologue  of  the  uterus  alone  ;  but  the  Author  considers  it  to  have  been 
satisfactorily  established  by  the  researches  of  Dr.  Leuckart,  that  it  answers  to  the  uteru« 
and  vagina  conjointly. 
51 


302  OF  GENERATION:  —  EMBRYONIC  DEVELOPMENT. 

and  a  'pars  genitalis,'  the  former  of  which,  extending  towards  the  urachus,  is 
converted  into  the  urinary  bladder.  A  partial  representation  of  this  phase  of  de- 
velopment, is  found  in  the  permanent  condition  of  the  Struthious  Birds  and  of 
the  Irnplacental  Mammalia.  The  external  opening  of  this  canal  is  soon  observed 
'to  be  bounded  by  two  folds  of  skin,  the  rudiments  of  the  labia  majora  in  the  fe- 
male, and  of  the  two  halves  of  the  scrotum  in  the  male ;  whilst  between  and  in 
front  of  these,  there  is  formed  an  erectile  body,  surmounted  by  a  gland,  and  cleft 
or  furrowed  along  its  under  surface.  This  body  in  the  female  is  retracted  into 
the  genito-urinary  canal,  and  becomes  the  clitoris,  whilst  the  margins  of  its  fur- 
row are  converted  into  the  nymphse  or  labia  minora  , ;  and  these  bound  the  '  atrium 
vaginae '  or  *  vestibule/  which  receives  the  orifices  of  the  urethra,  of  the  vagina, 
and  of  Gaertuer's  canals  when  they  are  present,  and  which  exactly  represents, 
therefore,  the  'sinus  genitalis '  of  the  early  embryo.  In  the  male,  on  the  other 
hand,  this  sinus  is  nearly  closed-in  at  a  very  early  period,  by  the  adhesion  of  the 
two  folds  of  integument  which  bound  it,  forming  that  portion  of  the  genito-uri- 
nary canal  (improperly  termed  the  t  urethra,')  which  receives  the  orifices  of  the 
vesical  or  true  urethra,  of  the  genital  sinus  (vesicula  prostatica),  and  of  the  vasa 
deferentia;  the  erectile  body  increases  in  prominence,  and  becomes  the  penis; 
whilst  the  margins  of  the  furrow  at  its  under  surface  unite  (at  about  the  14th 
week),  to  form  the  anterior  continuation  of  the  now-contracted  genito-urinary 
canal,  which  is  commonly  termed  the  spongy  portion  of  the  urethra. 

905.   Now  in  a  large  proportion  of  cases  of  so-called  Hermaphrodism  ^  there  has 
been  either  a  want  of  completeness  in  the  development  of  the  Male  organs,  so  that 
they  present  a  greater  or  less  degree  of  resemblance  to  those  of  the  female ;  or  the 
developmental  process  has  gone-on  to  an  abnormal  extent  in  the  Female  organs, 
so  that  they  come  to  present  a  certain  degree  of  resemblance  to  those  of  the  male. 
— One  of  the  most  common  malformations  of  the  male  organ  is  '  hypospadias/  or 
an  abnormal  opening  of  the  urethra  at  the  base  of  the  penis,  arising  from  incom- 
pleteness in  the  closure  of  the  edges  of  its  original  furrow.     But  when  the  deve- 
lopmental process  has  been  checked  at  an  earlier  period,  the  urogenital  sinus  may 
retain  more  nearly  its  original  character,  and  may  have  a  wide  external  opening 
beneath  the  root  of  the  penis,  so  as  to  resemble   the  female  vagina,  whilst  the 
penis  is  itself  destitute  of  any  trace  of  the  urethral  canal ;  in  some  of  these  cases, 
again,  the  testes  have  not  descended  into  the  scrotum ;  whilst  the  absence  of 
beard,  the  shrillness  of  the  voice,  and  the  fulness  of  the  mammae,  have  contri- 
buted to  impart  a  feminine  character  to  these  individuals,  their  male  attributes, 
however,  being  determined  by  the  seminiferous  character  of  the  essential  organs, 
the  testes.1 — In  the  female  organs,  on  the  other  hand,  a  greater  or  less  degree  of 
resemblance  to  those  of  the  male  may  be  produced  by  the  enlargement  of  the  cli- 
toris, by  its  furrowing  or  complete  perforation  by  the  urethra,  by  the  closure  of 
the  entrance  of  the  vagina  and  the  cohesion  of  the  labia,  so  as  to  present  a  like- 
ness to  the  unfissured  perineum  and  scrotum  of  the  male,  by  the  descent  of  the 
ovaries  through  the  inguinal  ring  into  the  position  of  the  male  testes,  and  by  the 
imperfect  development  of  the  uterus  and  mammae;  with  these  abnormalities  are 
usually  associated  roughness  of  the  voice  and  growth  of  hair  on  the  chin,  and  a 
psychical  character  more  or  less  virile. — True  Hermaphrodism,  in  which  there  is 
an  absolute  combination  of  the  essential  male  and  female  organs  in  the  same  in- 
dividual, is  comparatively  rare.     It  may  occur  under  the  forms  of  lateral  herma- 
phrodism,  in  which  there  is  a  genuine  ovary  on  one  side  and  a  testis  on  the  other, 
in  which  case  the  external  organs  are  usually  those  of  a  hypospadiac  male;  trans- 
verse hermaphrodism,  in  which  the  external  and  internal  organs  do  not  correspond, 
the  former  being  male  and  the  latter  female,  or  vice  versa; — and  double  or  verti- 
cal hermaphrodism,  in  which  the  proper  organs  characteristic  of  one  sex  have 

1  The  vesicula  prostatica  has  presented  an  unusual  development  in  some  of  these  cases ; 
see  Prof.  Weber  (loc.  cit.),  and  Prof.  Theile's  'Account  of  a  Case  of  Hypospadias,'  in 
"Muller's  Archiv.,"  1847. 


GENITAL  MALFORMATIONS  I — DEVELOPMENT  OF  SKELETON.    803 

existed,  with  the  addition  of  some  of  those  of  the  other;  this  is  the  rarest  of  all, 
and  it  is  not  certain  that  the  coexistence  of  testes  and  ovaria  on  the  same  side  has 
ever  been  observed  in  the  Human  species.1 

906.  We  have  now  to  follow  the  course  of  the  development  of  the  principal 
organs  of  Animal  life;  and  shall  first  notice  that  of  the  Skeleton. — We  have  seen 
that,  in  the  embryo  of  the  Vertebrated  animal,  the  future  vertebral  column  is 
marked-out  at  an  earlier  period  than  any  other  permanent  organ(§  889);   and 
that  indications  of  a  division   into  vertebrae  are  very  speedily  presented  in   the 
embryo  of  the  higher  classes.     The  earliest  formation,  however,  is  one  of  which 
we  recognize   no  traces  in  the  adult  condition  of  Man ;   namely,  a  longitudinal 
column,  tapering-off  to  a  point  at  the  cranial  and  caudal  extremities  of  the  em- 
bryo, and  occupying  the  place  of  the  future  bodies  of  the  vertebrae.     This,  which 
is  termed  the  '  chorda  dorsalis/  is  of  gelatinous  consistence,  and  is  composed  en- 
tirely of  cells;  it  is  enclosed  in  a  sheath,  which  gradually  acquires  the  structure 
of  a  fibrous  membrane,  and  which  also  invests  the  neural  axis  itself;  and  this  con- 
dition is  persistent  in  the  Amphioxus  and  the  Myxinoid  Fishes,  which  have  never 
any  other  spinal  column  than  the  chorda  dorsalis.     The  vertebras  seem  to  be  de- 
veloped, in  the  inferior  Vertebrata,  in  the  fibrous  sheath  of  the  chorda  dorsalis ; 
but  in  Birds  and  Mammals,  the  quadrangular  plates  which  show  themselves  at  a 
very  early  period  (Plate  II.  Fig.   12),  appear  to  have  an   independent  origin. 
These  gradually  increase  in  number  and  size,  so  as  to  surround  the  chorda  both 
above  and  below ;  sending  out,  at  the  same  time,  prolongations  from  the  inferior 
surface,  to  form  the  arches  destined  to  enclose  the  Spinal  Cord  or  neural  axis, 
which  are  hence  termed  by  Prof.  Owen  the  neural  arches.     In  this  primitive  con- 
dition, the  body  and  arches  of  each  vertebra  are  formed  by  one  piece  on  each  side ; 
and  these,  becoming  cartilaginous,  are  united  inferiorly  by  a  suture,  so  as  to  en- 
close the  chorda  in  a  sort  of  case  formed  by  the  bodies  of  the  vertebrae,  which  are 
still  hollow,  allowing  the  segments  of  the  chorda,  partially  separated  from  each 
other,  to  communicate  together :  this  condition,  also,  remains  persistent  in  certain 
of  the  Cartilaginous  Fishes.     With  the  concentric  growth  of  the  bodies  of  the 
vertebrae,  however,  the  chorda  dorsalis  gradually  wastes,  and  at  last  disappears ; 
but  previously  to  its  disappearance,  the  ossification  of  the  bodies  and  neural  arches 
of  the  vertebras  begins,  the  former  from  a  single  point  on  the  median  line,  the 
latter  by  separate  points  on  the  two  sides. 

907.  The  complete  typical  vertebra  (Fig.  233,  A)  essentially  consists,  according 
to  Prof.  Owen,2  of  the  centrum,  around  which  are  arranged  four  arches  enclosed 
by  processes  in  connection  with  it :  viz.,  superiorly,  the  neural  arch,  which  encloses 
the  neural  axis,  and  is  formed  by  a  pair  of  {  neurapophyses '  («,  n)  and  a  l  neural 
spine  '  (11  s);  inferiorly  the  haemal  arch,  which  is  in  like  special  relation  with  the 
centres  of  the  circulation,  but  may  be  expanded  around  the  Visceral  cavity  gene- 
rally, and  which  is  formed  of  a  pair  of  *  haemapophyses '  (h,  h)  and  the  '  haemal 
spine '  (h  s)  ;  and  two  lateral  arches,  enclosing  vascular  canals,  which  are  bounded 
by  the  '  diapophyses'  (J,  d)  and  the  *  parapophyses '  (jo,  p),  and  are  completed 
by  the  <•  pleurapophyses  '  (pi,  pi).     Of  these  elements,  the  centrum  is  the  most 
constant ;  and  next  to  these  are  the  neural  arches,  which  we  find  in  every  part  of 
the  vertebral  column  through  which  the  neural  axis  passes,  and  which  are  enor- 
mously developed  in  the  cranial  segments,  in  accordance  with  the  high  develop- 
ment of  their  nervous  mass.     The  haemal  arches  are  often  almost  entirely  deficient, 
HS  in  the  cervical  and  lumbar  vertebras  of  Man  and  the  Mammalia ;    but  in   the 
dorsal  vertebrae  they  are  very  largely  developed,  and  the  elements  of  the  lateral 
•arches  are  brought  into  connection  with  them,  so  as  to  form  the  enclosure  of  tbo 
visceral  cavity  (Fig.  233,  B).     From  the  pleurapophyses  are  occasionally  developed 

1  On  this  subject,  see  Prof.  Simpson's  Article  '  Hermaphrodism '  in  the  "  Cyclop,  of  Anat. 
and  Phys.,"  vol.  ii. 

a  See  his  "Archetype  Skeleton,"  his  "Lectures  on  Comparative  Anatomy,"  vol.  ii.,  an<1 
his  "  Discourse  on  the  Nature  of  Limbs." 


804      OP    GENERATION:  —  EMBRYONIC    DEVELOPMENT. 

a  pair  of  '  diverging  appendages '  (a,  a),  which  are  well  seen  in  the  ribs  of  Birds  ; 
and  these  are  considered  by  Prof.  Owen  to  be  the  fundamental  elements  of  the 


FIG.  233. 


A    „., 


Elements  of  a  Vertebra  according  to  Prof.  Owen: — A,  ideal  typical  vertebra: — B,  actual  tho- 
racic vertebra  of  a  Bird : — c,  centrum,  giving-off  d,  d,  the  diapophyses,  and  p,  p,  the  parapo- 
physes;  the  neunil  arch,  enclosing  the  spinal  cord*,  is  formed  by  n,  n,  the  neurapophyses 
and  n,  s,  the  neural  spine;  the  haemal  arch,  enclosing  the  great  centres  of  the  circulation,  is 
formed  by  h,  h,  the  haemapophyses,  and  k,  «,  the  haemal  spine.  From  both  the  neurapophy- 
ses and  haemapophyses  may  be  given-off  the  zygapophyses,  »,  z.  The  lateral  arches,  which 
may  enclose  the  vertebral  arteries  o,  o,  are  completed  by  the  pleurapophyses,  pi;  these  in  B 
are  bent  downwards,  so  as  to  form  part  of  the  haemal  arch,  and  give-off  the  diverging  appen- 
dages, a,  a. 

bones  of  the  'extremities'  or  c limbs/  those  of  the  anterior  extremity  being  the 
diverging  appendages  of  the  occipital  vertebra  (§  908),  and  those  of  the  posterior 
extremity  standing  in  the  same  relation  to  one  of  the  sacral  vertebrae.1 — The  ex- 
tremities make  their  first  appearance,  in  all  Vertebrata,  as  leaf-like  elevations 
from  the  parietes  of  the  trunk  (Fig.  228,  q  q,  r  r) ;  those  peculiarities  of  form  by 
which  they  are  adapted  to  specialities  of  function,  being  determined  by  subse- 
quent processes  of  development.  Thus  in  the  Human  foetus,  the  fingers  are  at 
first  united  by  the  primitive  blastema,  as  if  webbed  for  swimming;  but  this,  as 
Prof.  Miiller  justly  remarks,  is  less  to  be  regarded  as  an  approximation  to  the 
form  of  the  extremity  characteristic  of  aquatic  animals,  than  as  the  primitive  and 
most  general  form  of  the  hand,  the  individual  parts  of  which  subsequently  become 
more  completely  isolated  in  such  animals  as  require  to  use  them  separately. 

908.  It  is  in  the  cranial  segments,  that  the  Vertebral  elements  undergo  their 
most  remarkable  transformations,  the  departure  from  the  l  archetype '  being  more 
complete  in  Man  than  in  any  other  animal ;  so  that  it  is  only  by  tracing  them 
through  their  simplest  to  their  most  complicated  forms  and  arrangements,  that 
the  true  nature  of  the  latter  can  be  elucidated.  —  The  number  of  the  segments 
entering  into  the  skull  has  been  a  subject  of  much  discussion  among  those  who 
adopt  the  '  vertebral  theory '  of  its  composition  :  but  Prof.  Owen  agrees  with 
Oken  (the  original  propounder  of  that  theory)  in  fixing  the  number  at  four, 
which  corresponds  with  that  of  the  primary  divisions,  succeeding  each  other  in  a 

1  The  beautiful  chain  of  reasoning  by  which  this  position  is,  in  the  Author's  opinion, 
irrefutably  established,  is  contained  in  the  works  of  Prof.  Owen  already  referred-to ;  a 
sketch  of  it,  and  of  the  whole  '  Vertebral  Theory,'  will  be  found  in  the  Author's  "  Princi- 
ples of  General  Physiology." 


DEVELOPMENT  OF  VERTEBRAL  SKELETON.     805 

linear  series,  that  are  distinctly  marked-out  in  the  early  development  of  the  En- 
cephalon,  namely  (proceeding  from  behind  forwards),  the  Epencephalon,  the 
Mesencephalon,  the  Prosencephalon,  and  the  Rhinencephalon  (§  909) ;  and  also 
corresponding  with  the  number  of  the  nerves  of  special  sense,  the  Auditory, 
Ghistative,  Optic,  and  Olfactory,  which  issue  from  this  part  of  the  neural  axis 
with  the  same  segmental  regularity  that  the  ordinary  sensori-motor  nerves  do 
elsewhere. — Under  the  guidance  of  the  unerring  light  of  Comparative  Anatomy 
and  Development,  the  composition  of  the  Cranial  portion  of  the  skull — consist- 
ing of  the  bodies  and  neural  arches  of  the  four  cranial  vertebrae  —  has  been  de- 
termined by  Prof.  Owen  as  follows,  each  of  the  '  elements '  enumerated  being 
marked  as  distinct,  by  the  separateness  of  its  Centre  of  Ossification. 

[Fio.  234. 


Parietal  Segment  ;  or,  Vertebra—Man.] 

TABLE  I. 

Composition  of  the  Neural  Arches  of  the  Cranial  Vertebras,  in  Man. 
I.  EPENCEPHALIC  OK  OCCIPITAL  VERTEBRA. 

Centrum  ;  Basi-occipital  portion  of  the  Occipital  bone. 

Para  onh  ses  •      f  Coalesced  into  the  lateral  or  condyloid  portions  of  the  Occipital 
u'          bone'  the  ParaP°Physes  being  marked  by  the  scabrous  ridge 


giving  attachment  to  the  rectus  lateralis  muscle. 
Neural  Spine  ;  Proper  Occipital  bone. 

II.  MESENCEPIIALIC  OR  PARIETAL  VERTEBRA. 

Centrum  ;  Basi-sphenoid,  or  body  of  the  posterior  or  spheno-temporal  part  of  the 

Sphenoid  bone. 
.  Parapophyses  ;  Mastoid  portion  of  the  Temporal  bones. 

Neurapophyses  ;  Great  wings  of  Sphenoid  bone,  or  Ali-sphenoids. 
Neural  Spine;  Parietal  bones. 

III.  PROSENCEPHALIC  OR  FRONTAL  VERTEBRA. 

Centrum  ;   Pre-sphenoid,  or  body  of  the  anterior  or  spheno-orbital  part  of  the 

Sphenoid  bone. 
Parapophyses;  External  angular  processes  of  Frontal  bone  (the  post-frontals  of 

Fishes). 

Neurapophyses  ;  Small  wings  of  Sphenoid  bone,  or  Orbito-sphenoids. 
Neural  Spine  ;  Frontal  bone. 

IV.  RHINENCEPHALIO  OR  NASAL  VERTEBRA. 

Centrum  ;  Vomer. 

Neurapophyses;  Ossa  plana  of  Ethmoid  foone. 

Neural  Spine  ;  Nasal  bones. 


806       OF    GENERATION  I — E  MBRYONIC    DEVELOPMENT. 

[In  connection  with  the  foregoing,  we  have  two  ossified  '  sense-capsules ;'  the 
Auditory  forming  the  petrosal  portion  of  the  Temporal  hone  ;  and  the  Nasal 
forming  the  principal  part  of  the  Ethmoid  bone  with  the  Tuvbinate  bones.] 

The  mode  in  which  the  bones  of  the  Face  and  of  some  other  parts  are  formed 
from  the  hsemal  or  visceral  arches  of  the  cranial  vertebra,  will  be  seen  from  the 
following  table. 

TABLE  II. 

Composition  af  the  Ecemal  Arches  of  the  Cranial  Vertebra,  in  Man 

I.  EPENCEPHALIC  OR  OCCIPITAL  VERTEBRA. 

Pleurapophyses ;  Scapulae. 

Diverging  Appendages;  Bones  of  Arm,  Fore-arm,  and  Hand 

Hcemapophyses ;  Coracoid  processes  of  Scapulae    (Coracoid  bones    of  Oviparous 

Vertebrate). 
Hcemal  Spine;  Deficient. 

[The  Clavicles  and  first  segment  of  the  Sternum,  which  complete  the  Scapular 
arch  in  the  Mammalia,  are  regarded  by  Prof.  Owen  as  the  hsemapophyses  and 
hsemal  spine  of  the  Atlas,  or  highest  vertebra  of  the  trunk.] 

II.  MESENCEPHALIC  OR  PARIETAL  VERTEBRA. 

Pleurapophyses ;  Styloid  processes  of  Temporal  bone. 
Diverging  Appendages  ;  Greater  cornua  of  Hyoid  bone,  or  Thyro-hyals. 
Hcemapophyses ;  Lesser  cornua.  of  Hyoid  bone,  or  Cerato-hyals. 
Haemal  Spine;  Body  of  Hyoid  bone. 

III.  PROSENCEPHALIC  OR  FRONTAL  VERTEBRA. 

Pleurapophyses ;  Tympanic  portion  of  Temporal  bone. 
Diverging  Appendages  ;  Deficient. 

Hcemapophyses  ;  Articular  portion  of  Inferior  Maxilla. 
Hcemal  Spine ;  Dental  portion  of  Inferior  Maxilla. 

IV.  RHINENCEPHALIC  OR  NASAL  VERTEBRA. 

Pleurapophyses ;  Palatine  bones. 

Diverging  Appendages ;  Pterygoid  and  Malar  bones,  with  squamosal  and   zygo- 

matic  portions  of  Temperal  bones. 
Hcemapophyses  ;  Superior  Maxillary  bones. 
Hcemal  Spine;  Intermaxillary  bones. 

Thus  we  see  that,  in  the  anterior  segment,  we  have  the  highest  development  of 
the  Visceral  portion,  co-existing  with  the  lowest  development  of  tlie  Neural; 
this  last  being  obviously  related  to  the  comparatively-low  development  of  the 
pranglionic  mass  which  it  is  destined  to  protect.  —  The  development  of  the  soft 
parts  of  the  face  takes-place  in  conformity  with  that  of  the  vertebral  segments; 
these  being  formed  by  'visceral  arches'  which  meet  on  the  median  line  (Fig. 
228,  c,  d  d)'  and  the  knowledge  of  this  fact  enables  us  to  explain  those  conge- 
nital malformations  which  result  from  want  of  union  of  the  two  halves  on  the 
median  plane,  such  as  cleft-palate  and  hare-lip. 

909.  Within  the  Cranio-spinal  canal  thus  formed,  the  rudiment  of  the  Cere- 
bro-spinal  axis  is  found,  at  first  under  a  very  different  aspect  from  that  which  it 
subsequently  presents,  especially  as  regards  the  relative  proportion  of  its  different 
segments.  The  Encepbalon,  at  about  the  6th  week,  is  seen  as  a  series  of  vesi- 
cles arranged  in  a  line  with  each  other  (Fig.  235)  ;  of  which  those  that  represent 
the  Cerebrum  (&)  are  the  smallest,  whilst  that  which  represents  the  Cerebellum 
(d)  is  the  largest.  The  latter  (or  Epencephalon^),  as  in  Fishes,  is  single,  cover- 
ing the  fourth  ventricle  on  the  dorsal  surface  of  the  Medulla  Oblongata.  An- 
terior to  this  is  the  single  vesicle  (a)  of  the  Corpora  Quadrigemina  (or  Mesence- 
phalon),  from  which  the  optic  nerves  partly  arise ;  this  has  in  its  interior  a 
cavity,  the  ventricle  of  Sylvius.,  which  is  persistent  in  the  adult  Bird,  though 


DEVELOPMENT  OF  CRANIUM  AND  ENCEPHALON.   807 


FIG.  235. 


obliterated  in  the  adult  Mammal.  In  front  of  this  is  the  vesicle  (c)  of  the  Third 
Ventricle  (or  Deutc.ncpphalon),  which  also  contains  the  Thalami  Optici  ;  as  de- 
velopment proceeds,  this,  like  the  preceding, 
is  covered  by  the  enlarged  Hemispheres;  whilst 
its  roof  becomes  cleft  anteriorly  on  the  median 
line,  so  as  to  communicate  with  the  cavities 
which  they  include.  Still  more  anteriorly  (Z>) 
is  the  double  vesicle  (or  Prosencephalon)  which 
represents  the  hemispheres  of  the  Cerebrum ; 
this  has  a  cavity  on  either  side,  the  floor  of 
which  is  formed  by  the  Corpora  Striata,  and 
which  has  at  first  no  opening  except  into  the 
third  ventricle;  the  'fissure  of  Sylvius' 
(which  enables  the  membranes  of  the  brain  to 
be  reflected  into  the  lateral  ventricles)  being 
formed  at  a  later  period.  The  RhinencepJialon 
(consisting  of  the  Olfactive  ganglia)  is  seldom 
distinctly  marked-out  in  the  early  stage  of 

development  of  the  higher  Vertebrata,  though   about  three  times:  a,  vesicle  of  Corpora 
very  obvious   in  that  of  Fishes. — Thus  in  the   Quadrigemina;  b,  vesicle  of  Cerebral  He- 

small  proportion  which  the  Cerebral  Hemis-  J^'i^^l^ 
pheres  bear  to  the  other  parts,  in  the  absence  Qblongataj  «,  auditory  vesicle;  /.  olfae- 

of  convolutions,  in  the  deficiency  of  COmmis-  tory fossa;  h, liver ;**  caudal  extremity, 
sures,  and  in  the  general  simplicity  of  struc- 
ture of  the  whole,  there  is  a  certain  correspondence  between  the  brain  of  the 
Human  embryo  at  this  period,  and  that  of  a  Fish ;  but  the  resemblance  is  much 
stronger  between  the  foetal  brain  of  the  Fish  and  that  of  the  Mammal ;  indeed 
at  this  early  period  of  their  formation,  the  two  could  scarcely  be  distinguished  ; 
and  it  is  the  large  amount  of  change  which  the  latter  undergoes,  as  compared 
with  the  former,  that  causes  the  wide  dissimilarity  of  their  adult  forms. 

910.  At  about  the  12th  week,  we  find  the  Cerebral  Hemispheres  much  in- 
creased in  size,  and  archiug-back  over  the  Thalami  and  'Corpora  Quadrigemina 
(Fig.  236) ;  still,  however,  they  are  destitute  of  convolutions,  and  are  imperfectly 


Human  Embryo  of  sixth  week,  enlarged 


Brain  of  Human  Embryo  at  twelfth  week.  A,  seen  from  behind ;  B,  side  view ;  c,  sectional 
view; — a,  corpora  quadrigemina ;  bb,  hemispheres ;  d,  cerebellum;  e,  medulla  oblongata;/, 
optic  thalamus ;  g,  floor  of  third  ventricle ;  I,  olfactory  nerve. 

connected  by  commissures;  and  there  is  a  large  cavity  yet  existing  in  the  Coi- 
pora  Quadrigemina,  which  freely  communicates  with  the  Third  Ventricle.  In 
all  these  particulars,  there  is  a  strong  analogy  between  the  condition  of  the  brain 
of  the  Human  embryo  at  this  period,  and  that  of  the  Bird. — Up  to  the  end  of 
the  3d  month,  the  Cerebral  Hemispheres  present  only  the  rudiments  of  anterior 
lobes,  and  do  not  pass  beyond  that  grade  of  development  which  is  permanently 
characteristic  of  the  Marsupial  Mammalia,  the  Thalami  being  still  but  incom- 
pletely covered-in  by  them.  During  the  4th  and  part  of  the  5th  months,  how- 
ever, the  middle  lobes  are  developed  from  their  posterior  aspect,  and  cover  tho 
Corpora  Quadrigemina;  and  the  posterior  lobes,  of  which  there  was  no  previous 


808     OF    GENERATION: — EMBRYONIC    DEVELOPMENT. 

rudiment,  subsequently  begin  to  sprout  from  the  back  of  the  middle  lobes,  re- 
maining separated  from  them,  however,  by  a  distinct  furrow,  even  in  the, brain 
of  the  mature  foetus,  and  sometimes  in  that  of  older  persons.  In  these  and  other 
particulars,  there  is  a  very  close  correspondence  between  the  progressive  stages 
of  development  of  the  Human  Cerebrum,  and  those  which  we  encounter  in  the 
ascending  series  of  Mammalia.1 

911.  The  development  of  the  two  principal  Organs  of  Sense,  the  Eye  and  the 
Ear,  has  been  made  the  subject  of  careful  study  (in  the  Chick)  by  Mr.  H.  Gray.2 
— The  development  of  the  Eye  commences  by  a  protrusion  from  the  posterior  part 
of  the  anterior  cerebral  vesicle,  representing  the  '  vesicle  of  the  thalami  optici/ 
which  is  at  that  time  hollow;  and  the  cavity  of  the  protrusion  is  continuous 
with  that  of  the  vesicle  itself,  which  remains  as  the  <  third  ventricle/  This  pro- 
trusion is  lined,  like  the  cerebral  vesicle,  with  granular  matter,  which  gradually 
becomes  distinctly  cellular,  forming  a  layer  of  a  truly  ganglionic  character,  and 
whilst  this  change  is  taking  place,  the  protrusion  increases,  becomes  pear-shaped, 
and  is  at  last  connected  only  by  a  narrow  pedicle  with  the  vesicle  from  which  it 
sprang.  This  pedicle  closes-up,  so  as  completely  to  separate  the  two  cavities ; 
and  the  one  which  has  been  thus  budded-forth  constitutes  the  rudiment  of  the 
eye,  whilst  the  other  goes-on  to  form  the  ganglionic  bodies-  at  the  base  of  the  cere- 
brum, the  connecting  pedicle  becoming  the  optic  nerve,  which  connects  the  retina 
with  its  ganglionic  centre.  The  spherical  extremity  of  the  protrusion  is  absorbed, 
and  the  retina,  or  vesicular  lining,  becomes  attached  to  the  margin  of  the  lens, 
which  is  in  the  mean  time  developed  in  the  interior  of  the  cavity,  and  is  at  first 
completely  surrounded  by  the  retina.  The  formation  of  the  Coats  of  the  eye 
takes-place  subsequently ;  the  development  even  of  the  *  fibrous  lamina '  and  of 
the  '  membrana  Jacobi '  of  the  Retina  itself,  not  proceeding  until  after  its  cellular 
layer  has  been  very  distinctly  formed.  It  is  a  curious  circumstance,  and  one  not 
very  easy  to  account  for,  that  the  development  of  the  Eye  should  commence  from 
the  Deutencephalic  and  not  from  the  Mesencephalic  vesicle ;  as  it  is  in  the  latter 
that  the  proper  '  optic  ganglia '  originate,  with  which  the  optic  nerves  come  at 
last  to  have  their  principal  connection,  their  connection  with  the  '  thalami  optici ' 
being  much  less  close. — The  Auditory  apparatus  takes  its  origin  in  a  portion  of 
the  Epencephalic  vesicle,  which  protrudes  on  either  side ;  its  cavity  at  first  com- 
municating with  that  of  the  vesicle,  which  remains  permanent  as  the  'fourth  ven- 
tricle/ As  its  protrusion  increases,  it  becomes  elongated  and  pear-shaped,  and  is 
only  connected  with  the  central  mass  by  a  pedicle  whose  canal  gradually  closes-up ; 
the  sac  thus  cut-off  becomes  the  vestibular  cavity,  and  the  pedicle  the  auditory 
nerve.  At  first  there  is  no  vestige  either  of  cochlea,  semi-circular  canals  or  tym- 
panic apparatus ;  but  the  sac  presents  the  simple  character  which  it  permanently 
retains  in  the  Cephalopoda  and  the  lower  Fishes.  Gradually,  however,  the  semi- 
circular canals  are  developed,  by  a  contraction  and  folding-in  of  the  walls  of  the 
vestibular  sac ;  and  the  cochlea  is  probably  formed  as  an  offset  from  it.  At  the 
same  time,  the  formation  of  cartilage,  and  subsequently  of  bone,  takes  place 
around  the  auditory  sac  and  its  prolongations,  forming  the  '  sense-capsule/  which, 
in  the  higher  Vertebrata,  coalesce  with  the  vertebral  elements  to  form  the  tem- 
poral bone.  It  is  very  interesting  to  remark,  that  the  membranous  labyrinth, 
between  the  eighth  and  thirteenth  days  in  the  Chick,  has  a  structure  almost 
precisely  similar  to  that  of  the  retinal  expansion  of  the  same  period;  consisting, 
like  it,  of  a  distinct  but  very  delicate  fibrous  mesh,  in  the  spaces  between  which 
are  deposited  a  quantity  of  granular  matter  and  numerous  nucleated  cells,  whilst  its 
exterior  is  composed  of  a  dense  mass  of  nuclei,  almost  precisely  analogous  to  the 
granular  particles  which  form  a  large  part  of  the  entire  substance  of  the  retina. 

912.  Of  Sex. — Although  nothing  is  known  of  the  conditions  on  which  the  dif- 

1  See  an  account  of  the  observations  of  Prof.  Retzius  on  the  Development  of  the  Cere- 
brum, in  the  "  Archives  d'Anatomie  Ge"nerale  et  de  Physiologic,"  1846 
*  "  Philosophical  Transactions,"  1850. 


COMPARISON     OF    MALE    AND     FEMALE     SEXES.          809 

ferentiation  of  Sex  immediately  depends,  yet  there  is  strong  statistical  evidence 
that  the  relative  numbers  of  Males  and  Females  are  in  some  way  influenced  by 
the  relative  ayes  of  the  parents.  The  following  table  expresses  the  average 
results  collected  by  M.  Hofacker  '  in  Germany,  and  by  Mr.  Sadler2  in  Britain; 
between  which  it  will  be  seen  that  there  is  a  very  striking  general  correspond- 
ence, although  both  were  drawn  from  a  too-limited  series  of  observations.  The 
numbers  indicate  the  proportion  of  Male  births  to  100  Females,  under  the  several 
conditions  mentioned  in  the  first  column  : — 

Hofacker.  Sadler. 

Father  younger  than  Mother 90-6         Father  younger  than  Mother 86-5 

Father  and  Mother  of  equal  age..     90-0  Father  and  Mother  of  equal  age..  94-8 

Father  older  by  1  to  6  years 103-4         Father  older  by  1  to  6  years 103-7 

6  to  9 124-7             "          "          6  to  11 126-7 

9  to  18 143-7             "          «           11  to  16 147-7 

"          "           18  and  more 200-0             "          "           16  and  more 163-2 

From  this  it  appears,  that  the  more  advanced  age  of  the  Male  parent  has  a  very 
decided  influence  in  occasioning  a  preponderance  in  the  number  of  Male  infants ; 
and  this  tallies  with  the  fact,  that  taking  the  average  of  the  whole  of  Europe, 
over  which  (as  a  general  rule)  the  state  and  customs  of  society  bring-about  a  de- 
cided preponderance  of  age,  among  married  couples,  on  the  side  of  the  husband, 
the  proportion  is  about  106  males  to  100  females.  This  does  not  hold  good,  how- 
ever, in  regard  to  illegitimate  offspring,  the  parents  of  which  may  generally  be 
presumed  to  be  more  nearly  on  an  equality  in  this  respect ;  and  it  is  curious  that 
the  proportion  of  these  has  averaged  102-5  males  to  100  females,  in  places 
where  the  proportion  of  legitimate  births  was  105f  males  to  100  females. — We 
are  not  likely  to  obtain  data  equally  satisfactory  in  regard  to  the  influence  of  more 
advanced  age  on  the  part  of  the  Female  parent ;  as  a  difference  of  10  or  15  years 
on  that  side  is  not  so  common.  If  it  exist  to  the  same  extent,  it  is  probable  that 
the  same  law  would  be  found  to  prevail  in  regard  to  Female  children  born  under 
such  circumstances,  as  will  be  stated  (§  913)  with  respect  to  the  Male; — namely, 
that  the  mortality  is  greater  during  embrypnic  life  and  early  infancy,  so  that  the 
preponderance  is  reduced.  Even  at  birth,  there  is  a  manifest  difference  in  the 
physical  conditions  of  infants  of  different  sexes ;  for,  in  the  average  of  a  large 
number,  there  is  a  decided  preponderance  on  the  side  of  the  Males,  both  as  to 
the  length  and  the  weight  of  the  body.  And  it  seems  not  improbable  that  this 
difference  has  a  decided  influence  upon  the  greater  loss  of  life  in  the  act  of  par- 
turition, which  occurs  among  Male  infants.3 

1  "  Annales  d' Hygiene,"  Oct.  1829.  2  "  Law  of  Population,"  vol.  ii,  p.  343. 

3  [In  Dr.  Sutton's  second  annual  report  relative  to  the  births,  marriages  and  deaths  in 
Kentucky,  a  vast  number  of  highly  important  and  interesting  facts  are  detailed.  Some  of 
these  are  briefly  stated. 

The  returns  for  the  twelve  months  embraced  in  the  report,  give  25,000  births.  This 
gives  one  birth  to  every  thirty-six  of  the  population. 

The  time  of  birth  ranged  as  follows:  December,  2,747;  November,  2,220;  October, 
2,155;  August,  2,135;  September,  2,112;  March,  2,022:  April,  1,938;  May,  1,925; 
February,  1,872;  July,  1,861;  June,  1,815;  January,  1,775.  For  439  births  the  month 
is  not  stated. 

The  sexes  of  only  24,832  births  are  reported.  Of  these.  13,027  were  males,  and  11,806 
females.  The  greatest  excess  of  male  births  was  in  March,  which  gave  209,  then  Sep- 
tember, August,  December,  &c.  May  was  the  only  month  that  gave  an  excess  of  female 
births.  These  facts,  with  reference  to  the  proportion  of  the  sexes  of  the  new-born,  go  to 
corroborate  the  theory  of  Villerme,  of  Paris,  and  Dr.  Emerson,  of  Philadelphia.  This 
theory  is,  that  certain  causes,  as  great  heat  of  summer,  over-working  and  under-feeding, 
and  prevalence  of  epidemics,  in  short,  whatever  tends  to  depress  the  physical  and  moral 
powers  tends  also  to  diminish  fecundity,  and  reduce  the  excess  of  male  births.  Now  it 
•will  be  observed  that  the  conceptions  which  took  place  in  August  (the  month  of  the  great- 
est mortality)  there  was  an  excess  of  females,  as  witness  the  births  in  May,  nine  month? 
afterward.  Of  the  conceptions  of  September,  (next  to  August  in  mortality)  born  in  June, 
there  was  the  smallest  excess  of  males  —  while  the  conceptions  of  November,  December, 
January,  February  and  March,  gave  a  male  excess  of  12  per  cent. — those  of  April,  May, 
August,  September  and  October,  gave  but  5  per  cent. 


810    OF  GENERATION:  —  EMBRYONIC   DEVELOPMENT. 

I.  The  Length  of  the  body  in  fifty  new-born  infants  of  each  sex,  as  ascertained 
by  Quetelet,1  was  as  follows  : — 

Males.      Females.    Total. 

From  16  to  17  inches"  (French) 246 

"     17  to  18 8  19          27 

«     18  to  19 28          18          46 

"     19  to  20 12  8          20 

»     20  to  21 Oil 

From  these  observations,  the  mean  and  the  extremes  of  the  Lengths  of  the  male 
and  female  respectively,  were  calculated  to  be, — 

Males.  Females. 

Minimum 16  inches,  2  lines  16  inches,  2  lines. 

Mean 18  6  18  1J 

Maximum 19  8  20  6 

Notwithstanding  that  the  maximum  is  here  on  the  side  of  the  Female  (this  being 
an  accidental  result,  which  would  probably  have  been  otherwise,  had  a  larger 
number  been  examined),  the  average  shows  a  difference  of  4^  lines  in  favour  of 
the  Male. 

II.  The  inequality  in  the  Weights  of  the  two  is  even  more  remarkable;  the 
observations  of  M.  Quetelet3  were  made  upon  63  male  and  56  female  infants. 

Infants  weighing  from  Males.        Females.        Total. 

1  to  1£  kilog.4 Oil 

Ijto2 Oil 

2  to2£ 3  7  10 

2£to3 13  14  27 

3  to  3£ 28  23  51 

3£  to  4 14  7  21 

4  to  4^ 538 

The  extremes  and  means  were  as  follows : — 

Males.  Females. 

Minimum 2-34  kilog.  1-12  kilog. 

Mean 3-20  2-91 

Maximum ."..  4-50  4-25 

in.  The  average  Weight  of  infants  of  both  sexes,  as  determined  by  these  in- 
quiries, is  3-05  kilog.  or  6-77  Ibs. ;  and  this  corresponds  almost  exactly  with  the 
statement  of  Chaussier,  whose  observations  were  made  upon  more  than  20,000 
infants.  The  mean  obtained  by  him,  without  reference  to  distinction  of  sex, 
was  6. 75  Ibs. ;  the  maximum  being  11-3  Ibs.,  and  the  minimum  3-2  Ibs.5  The 
average  in  this  country  is  probably  rather  higher;  according  to  Dr.  Joseph 
Clarke,6  whose  inquiries  were  made  on  60  males  and  60  females,  the  average  of 
Male  children  is  1\  Ibs. ;  and  that  of  Females  6f  Ibs.  He  adds  that  children 
which  at  the  full  time  weigh  less  than  5  Ibs.,  rarely  thrive  ;  being  generally 
feeble  in  their  actions,  and  dying  within  a  short  time.  Several  instances  are  on 
record,  of  infants  whose  weight  at  birth  exceeded  15  Ibs.  It  appears  that  healthy 
females,  living  in  the  country,  and  engaged  in  active  but  not  over-fatiguing  oc- 
cupations, have  generally  the  largest  children  ;  and  this  is  what  might  be  expected 
a  priori,  from  the  superior  energy  of  their  nutritive  functions. 

There  were  265  plurality  cases,  that  is,  twin  births.  Of  these,  207,  or  one  in  every  9-5, 
were  whites :  38,  or  one  in  every  89,  coloured.  There  were  three  cases  of  triplets,  one 
white  and  two  coloured. 

Of  still-births,  there  was  one  in  42  among  the  whites,  and  one  in  31  among  the  coloured. 

The  weight  of  several  children  is  reported,  there  being  a  number  who  weighed  11,  11^ 
and  llf  pounds  at  birth.  One  weighed  14£  pounds,  naked. — ED.] 

'  "  Sur  1'Homme,"  torn.  ii.  p.  8. 

a  The  French  inch  is  about  one-fifteenth  more  than  the  English. 

s  Op.  cit,  torn.  ii.  p.  35.  4  The  kilogramme  is  equal  to  2-22  Ibs.  avoirdupois. 

6  These  numbers  have  been  erroneously  stated  in  many  Physiological  works :  owing  ti 
the  difference  between  the  French  and  English  pound  not  having  been  allowed-for. 

'  "  Philosophical  Transactions,"  vol.  Ixxvi. 


COMPARISON     OF     MALE     AND     FEMALE     SEXES.         811 
FIG.  237. 


(I 


Diagram  representing  the  Comparative  Viability  of  the  Male  and  Female  at  different  Ages. 

913.  There  appears  to  be,  from  the  first,  a  difference  in  the  Viability  (or  pro- 
bability of  life)  of  Male  and  Female  children  ;  for,  out  of  the  total  number  born 
dead,  there  are  3  Males  to  2  Females  :  this  proportion   gradually  lessens,  how- 
ever, during  early  infancy ;  being  about  4  to  3  during  the  first  two  months,  and 
about  4  to  5  during  the  next  three  months ;  after  which   time   the  deaths  are 
nearly  in  proportion  to  the  numbers  of  the  two  sexes  respectively,  until  the  age 
of  puberty.     The  viability  of  the  two  sexes  continues  to  increase  during  child- 
hood ;  and  attains  its  maximum  between  the  13th  and  14th  years.     For  a  short 
time  after  this  epoch  has  been  passed,  the  rate  of  mortality  is  higher  in  Females 
than  in   Males ;  but  from   about  the  age   of  18  to  28,  the  mortality  is  much 
greater  in  Males,  being  at  its  maximum  at  25,  when  the  viability  is  only  half 
what  it  is  at  puberty.     This  fact  is  a  very  striking  one  ;  and  shows  most  forcibly 
that  the  indulgence  of  the  passions  not  only  weakens  the  health,  but  in  a  great 
number  of  instances  is  the  cause  of  a  very  premature  death.     From  the  age  of 
28  to  that  of  50,  the  mortality  is  greater  and  the  viability  less  on  the  side  of  the 
Female;  this  is  what  would  be  anticipated  from  the  increased  risk  to  which  she 
is  liable  during  the   parturient  period.     After  the  age  of  50,  the   mortality  is 
nearly  the  same  for  both.  —  These  facts  have  been  expressed  by  Quetelet  (Op. 
cit.)  in  a  form  which  brings  them  prominently  before  the  eye  (Fig.  237).     The 
relative  viability  of  the  Male  at  different  ages  is  represented  by  a  curved  line ; 
the  elevation  of  which   indicates  its  degree,  at  the  respective  periods  marked 
along  the  base  line.     The  dotted  line  which  follows  a  different  curve,  represents 
the  viability  of  the  Female.     Starting  from  a,  the  period  of  birth,  we  arrive  at 
the  maximum  of  viability  for  both  at  b:    from   this   point,  the  Female  curve 
steadily  descends  towards  w,  at  first  very  rapidly,  but  afterwards  more  gradually  ; 
whilst  the  male  curve  does  not  quite  descend  so  soon,  but  afterwards  falls  much 
lower,  its  minimum  being  c;  which  corresponds  with  the  age  of  25  years.     It 


812     OF    GENERATION:— EMBRYONIC    DEVELOPMENT 

FIG.  238. 


Diagram  representing  the  Comparative  Heights  and  Weights  of  the  Male  and  Female  at 

different  Ages. 

afterwards  ascends  to  6?,  which  is  the  maximum  of  viability  subsequently  to  the 
age  of  puberty ;  this  point  is  attained  at  the  age  of  30  years,  from  which  period 
up  to  50,  the  probability  of  life  is  greater  in  the  Male  than  in  the  Female.  In 
the  decline  of  life,  there  seems  little  or  no  difference  for  the  two  sexes. 

914.  Similar  diagrams  have  been  constructed  by  Quetelet,  to  indicate  the  rela- 
tive Heights  and  Weights  of  the  two  sexes  at  different  ages  (Fig.  238).  —  In 
regard  to  Height  it  may  be  observed,  that  the  increase  is  most  rapid  in  the  first 
year,  and  that  it  afterwards  diminishes  gradually;  between  the  ages  of  5  and  16 
years,  the  annual  increase  is  very  regular.  The  difference  between  the  Height 
of  the  Male  and  Female  which  has  been  already  stated  to  present  itself  at  birth, 
continues  to  increase  during  infancy  and  youth ;  it  is  not  very  decided,  however, 
until  about  the  15th  year,  after  which  the  growth  of  the  Female  proceeds  at  a 
much-diminished  rate,  whilst  that  of  the  Male  continues  in  nearly  the  same 
degree,  until  about  the  age  of  19  years.  It  appears,  then,  that  the  Female 
comes  to  her  full  development  in  regard  to  Height,  earlier  than  does  the  Male. 
It  seems  probable,  from  the  observations  of  Quetelet,  that  the  full  Height  of 
the  Male  is  not  generally  attained  until  the  age  of  25  years.  At  about  the  age 
of  50,  both  Male  and  Female  undergo  a  diminution  of  their  stature,  which  con- 
tinues during  the  latter  part  of  life. — The  proportional  Weight  of  the  two  sexes 
at  different  periods,  corresponds  pretty  closely  with  their  height.  Starting  from 
birth,  the  predominance  then  exhibited  by  the  Male  gradually  increases  during 
the  first  few  years ;  but  towards  the  period  of  puberty,  the  proportional  weight 
of  the  Female  increases;  and  at  the  age  of  12  years,  there  is  no  difference  be- 
tween the  two  sexes  in  this  respect.  The  weight  of  the  Male,  however,  then 
increases  much  more  rapidly  than  that  of  the  Female,  especially  between  the  ages 
of  15  and  20  years;  after  the  latter  period,  there  is  no  considerable  increase  on 
the  side  of  the  Male,  though  his  maximum  is  not  attained  until  the  age  of  40 ; 
and  there  is  an  absolute  diminution  on  the  part  of  the  Female,  whose  weight  re- 
mains less  during  nearly  the  whole  period  of  child-bearing.  After  the  termina- 
tion of  the  parturient  period,  the  weight  of  the  Female  again  undergoes  an 
increase,  and  its  maximum  is  attained  at  about  50.  In  old  age,  the  weight  of 
both  sexes  undergoes  a  diminution  in  nearly  the  same  degree.  The  average 
Weights  of  Male  and  Female  that  have  attained  their  full  development,  are  20 


PECULIARITIES    OF   FEMALE    CHARACTER: — LACTATION.  813 

times  those  of  the  new-born  Infants  of  the  two  sexes  respectively.     The  Heights, 
on  the  other  hand,  are  about  3£  timesas  great. 

915.  The  chief  differences  in  the  Constitution  of  the  two  sexes,  manifest  them- 
selves during  the  period  when  the  Generative  function  of  each  is  in  its  greatest 
vigour.     Many  of  these  distinctions  have  been  already  alluded-to ;  but  there  are 
others  of  too  great  importance  to  be  overlooked ;  and  these  chiefly  relate  to  the 
Nervous  System  and  its  functions.     There  is  no  obvious  structural  difference  in 
the  Nervous  System  of  the  two  sexes  (putting  aside  the  local  peculiarities  of  its 
distribution  to  the  organs  of  generation),  save  the  inferior  size  of  the  Cerebral 
Hemispheres  in  the   Female.     This  difference,  which  is  not  observed  in  other 
parts  of  the  Encephalon,  is  readily  accounted-for  on   the  principles  formerly 
stated  (§  574),  when  we  compare  the  psychical  character  of  Woman  with  that 
of  Man ;  for  there   can  be  no  doubt  that — putting  aside  the  exceptional  cases 
which  now  and  then  occur — the  intellectual  powers  of  Woman   are  inferior  to 
those  of  Man.     Her  intuitive  powers  are  certainly  greater  than  his;  her  percep- 
tions are  more  acute,  her  apprehensions  quicker ;  and  she  has  a  remarkable'power 
of  interpreting  the  feelings  of  others,  which  gives  to  her,  not  only  a  much  more 
ready  sympathy  with  them,  but  that  facility  in  guiding  her  actions  so  as  to  be  in 
accoi dance  with  them,  which  we  call  tact.     This  tact  bears  a  close  correspondence 
with  the  unconscious  adaptiueness  to  particular  ends,  which  we  see  in  Instinctive 
actions.     Notwithstanding  the  superiority  of  her  perceptive  faculties,  her  capa- 
bility of  sustained  mental  exertion  is  much  less;  and  though  her  views  are  often 
peculiarly  distinguished  by  the  clearness  and  decision  which  result  from  the 
strength  of  her  intuitive  sense,  they  are  generally  deficient  in  that  comprehensive- 
ness which  brings  the  whole  case  to  be  judged  of,  and  which  is  consequently 
necessary  for  their  stability.     With  less  of  volitional  power  than  Man  possesses, 
she  has  the  emotional  in  a  much  stronger  degree.     The  emotions,  therefore,  pre- 
dominate ;  and  more  frequently  become  the  leading  springs  of  action,  than  they 
are  in   Man.     By  their  direct  influence   upon   the  bodily  frame,  they  produce 
changes  in  the  Organic  functions,  which  far  surpass  in  degree  anything  of  the  same 
kind  that  we  ordinarily  witness  in  Man;  and  they  thus  not  unfrequently  occasion 
symptoms  of  an  anomalous  kind,  which  are  very  perplexing  to  the  Medical  prac- 
titioner, though  very  interesting  to  the  Physiological  observer.     But  they  also 
act  as  powerful  motives  to  the  Will ;  and,  when  strongly  called-forth,  produce  a 
degree  of  vigour  and  determination,  which  is  very  surprising  to  those  who  have 
usually  seen  the  individual  under  a  different  aspect.     But  this  vigour,  being  due 
to  the  strong  excitement  of  the  Feelings,  and  not  to  any  inherent  strength  of 
Intellect,  is  only  sustained  during  the  persistence  of  the  motive,  and  fails  as  soon 
as  this  subsides.     The  feelings  of  Woman,  being  frequently  called-forth  by  the 
occurrences  she  witnesses  around  her,  are  naturally  more  disinterested  than  thoso 
of  Man;  his  energy  is  more  concentrated  upon  one  object;  and  to  this  his  In- 
tellect is  directed  with  an  earnestness  that  too  frequently  either  blunts  his  feel- 
ings, or  carries  them  along  in  the  same  channel,  thus  rendering  them  selfish. — 
In  regard  to  the  inferior  development  of  her  Intellectual  powers,  therefore,  and 
to  the  predominance  of  the  Instinctive,  Woman  must  be  considered  as  ranking 
below  Man ;  but  in  the  superior  purity  and  elevation  of  her  Feelings,  she  is  as 
highly  raised  above  him.     Her  whole  character,  Psychical  as  well  as  Corporeal,  is 
beautifully  adapted  to  supply  what  is  deficient  in  Man  :  and  to  elevate  and  refine 
those  powers,  which  might  otherwise  be  directed  to  low  and  selfish  objects. 

5. —  Of  Lactation. 

916.  The  new-born  Infant  in  the  Human  species,  as  in  the  class  of  Mammalia 
generally,  is  supplied  with  nourishment  by  a  secretion  elaborated  from  the  blood 
of  its  maternal  parent,  by  certain  glandular  organs  known  as  the   Mammary. 
The  structure  of  these,  which  has  been  thoroughly  investigated  by  Sir  A.  Cooper1 

1  "  On  the  Anatomy  of  the  Breast,"  1840. 


814 


OF    GENERATION 
FIG.  239. 


LACTATION. 

FIG.  240. 


\3 


The  Mammary  Gland  after  the  removal  of  the  skin, 
as  taken  from  the  subject  three  days  after  delivery : 
1,  the  surface  of  the  chest;  2,  subcutaneous  fat;  3, 
the  skin  covering  the  gland;  4,  circumference  of  the 
gland;  5,  its  lobules  separated  by  fat ;  6,  the  lactife- 
rous ducts  converging  to  unite  in  the  nipple ;  7,  the 
nipple  slightly  raised,  and  showing  the  openings  of 
the  tubes  at  its  extremity. 


A  vertical  section  of  the  Mammary 
Gland,  showing  its  thickness  and  the 
organs  of  the  lactiferous  ducts :  1,  2, 
3,  its  pectoral  surface;  4,  section  of 
the  skin  on  the  surface  of  the  gland; 

5,  the  thin  skin  covering  the  nipple  ; 

6,  the  lobules  and  lobes  composing  the 
gland ;  7,  the  lactiferous  tubes  com- 
ing  from    the   lobules;    8,  the   same 
tubes  collected  in  the  nipple. 


and  Mr.  Birkett,'  is  extremely  simple.  Each  gland  is  composed  of  a  number  of 
separate  glandules,  which  are  connected  together  by  fibrous  or  fascial  tissue,  in 
such  a  manner  as  to  allow  a  certain  degree  of  mobility  of  its  parts,  one  upon  an- 
other, which  may  accommodate  them  to  the  actions  of  the  Pectoralis  muscle 
whereon  they  are  bound-down ;  and  the  glandules  are  also  connected  by  the  rami- 
fications of  the  lactiferous  tubes,  which  intermingle  with  one  another  in  such  a 
manner  as  to  destroy  the  simplicity  and  uniformity  of  their  divisions,  although 
they  rarely  inosculate.  The  mammillary  tubes,  or  terminal  ducts  contained  in 
the  nipple,  are  usually  about  ten  or  twelve  in  number ;  they  are  straight,  but  of 
somewhat  variable  size;  and  their  orifices,  which  are  situated  in  the  centre  of  the 
nipple,  and  are  usually  concealed  by  the  overlapping  of  its  sides,  are  narrower 
than  the  tubes  themselves.  At  the  base  of  the  nipple,  these  tubes  dilate  into 
reservoirs,  which  extend  beneath  the  areala  and  to  some  distance  into  the  gland, 
when  the  breast  is  in  a  state  of  lactation.  These  are  much  larger  in  many  of 
the  lower  Mammalia,  than  they  are  in  the  Human  female;  their  use  is  to  sup- 
ply the  immediate  wants  of  the  child  when  it  is  first  applied  to  the  breast,  so 
that  it  shall  not  be  disappointed,  but  shall  be  induced  to  proceed  with  sucking 
until  the  '  draught '  be  occasioned  (§  833).  From  each  of  these  reservoirs  com- 
,  mence  five  or  six  branches  of  the  lactiferous  tubes,  each  of  which  speedily  sub- 
divides into  smaller  ones;  and  these  again  divaricate,  until  their  size  is  very 
much  reduced,  and  their  extent  greatly  increased  (Fig.  241).  These,  like  the 
reservoirs  and  mammillary  tubes,  are  composed  of  a  fibrous  coat  lined  by  a  mu- 
cous membrane;  the  latter  is  highly  vascular,  and  forms  a  secretion  of  its  own, 
which  sometimes  collects  in  considerable  quantity  when  the  milk  ceases  to  be 
produced.  The  smaller  subdivisions  of  the  lactiferous  tubes  proceed  to  distinct 
lobuli  in  each  glandule;  so  that  when  a  branch  of  a  mammillary  tube  has  been 
filled  with  injection,  its  attached  lobules,  if  separated  from  each  other  by  long 
maceration,  are  like  a  bunch  of  fruits  clustered  upon  a  stock  (Fig.  242).  When 
1  "The  Diseases  of  the  Breast,  and  their  Treatment,"  1850. 


STRUCTURE    AND    DEVELOPMENT    OF    MAMMARY   GLAND. 
FIG.  241. 


815 


Distribution  of  the  Milk-ducts  in  the  Manama  of  the  Human  female,  during  lactation ;  the 
ducts  injected  with  wax. 

the  lactiferous  tubes  are  pursued  to  their  ultimate  distribution,  they  are  found  to 
terminate  in  follicles,  whose  size,  in  full  lactation,  is  that  of  a  hole  pricked  in 
paper  by  the  point  of  a  very  fine  pin,  so  that,  when  distended  with  quicksilver 
or  milk,  they  are  just  visible  to  the  naked  eye ;  at  other  times,  however,  the  fol- 
licles do  not  admit  of  being  injected,  though  the  lactiferous  tubes  may  have  been 
completely  filled.  They  are  lined  by  a  continuation  of  the  same  membrane  with 
that  which  lines  the  ducts ;  and  this  possesses  a  high  vascularity.  The  arteries 
which  supply  the  glandules  with  blood,  become  very  large  during;  lactation ;  and 
their  divisions  spread  themselves  minutely  on  the  follicles.  From  the  blood 
which  they  convey,  the  milk  is  secreted  and  poured  into  the  follicles,  whence  it 
flows  into  the  ducts.  The  inner  surface  of  the  milk-follicles,  in  common  with 
other  glandular  structures,  is  covered  with  a  layer  of  epithelium-cells  (Fig.  243), 
as  was  first  observed  by  Prof.  Goodsir;  and  these,  being  seen  to  contain  milk- 
globules,  may  without  doubt  be  regarded  as  the  real  agents  in  the  secreting  pro- 
Absorbent  vessels  are  seen  to  arise  in  large  numbers  in  the  neighbourhood 


of  the  follicles  ;  their  function  appears  to  be,  to  absorb  the  more  watery  part  of 
the  milk  contained  in  the  follicles  and  tubes,  so  as  to  render  it  more  nutrient 
than  it  is  when  first  secreted ;  and  also  to  relieve  the  distension  which  would 
occur,  during  the  absence  of  the  child,  from  the  continuance  of  the  secreting 
process. 

917.  The  Mammary  gland  may  be  detected  at  an  early  period  of  foetal  exist- 
ence ]  being  easily  distinguishable  from  the  surrounding  parts  by  the  redness  of 
its  colour  and  its  high  vascularity,  especially  when  the  whole  is  injected.  At 
this  period,  it  presents  no  difference  in  the  male  and  female;  and  it  is  not  until 
near  the  period  of  puberty  that  any  striking  change  manifests  itself,  the  gland 


816  OF  GENERATION: — LACTATION. 

FIG.  242.  FIG.  243. 


Termination  of  portion  of 

Milk-duct  in  a  cluster  offol-  Ultimate  follicle*  of  Mam- 

licles  ;  from  a  mercurial  in-  mary  gland,  with  their  secret- 

jection;  enlarged  four  times.  ing  cells  a,  a,  and  nuclei,  b,  b. 

continuing  to  grow,  in  the  one  sex  as  in  the  other,  in  proportion  to  the  body  at 
large.  At  about  the  age  of  thirteen  years,  however,  the  enlargement  of  the 
gland  commences  in  the  Female  ;  and  by  sixteen,  it  is  greatly  evolved,  and  some 
of  the  lactiferous  tubes  can  be  injected.  At  about  the  age  of  twenty,  the  gland 
attains  its  full  size  previous  to  lactation ;  but  the  milk-follicles  cannot  even  then 
be  injected  from  the  tubes.  During  pregnancy,  the  mammae  receive  a  greatly- 
increased  quantity  of  blood.  This  determination  often  commences  very  early,  and 
produces  a  feeling  of  tenderness  and  distension,  which  is  a  valuable  sign  (where 
it  exists  in  connection  with  others)  of  the  commencement  of  gestation  (§  870). 
A  true  lacteal  secretion  usually  commences  about  the  third  or  fourth  month  of 
pregnancy,  and  may  be  obtained  by  pressure  carefully  applied.  This  may  be 
turned  to  useful  account,  in  diagnosing  cases  of  concealed  or  doubtful  pregnancy 
from  cases  of  simple  suppression  of  the  catamenia;  but  it  will  not  serve  to  dis- 
tinguish true  pregnancy  from  spurious,  or  from  the  distension  of  the  uterus  by 
tumours.1  The  vascularity  of  the  gland  continues  to  increase  during  pregnancy; 
and  at  the  time  of  parturition,  its  lobulated  character  can  be  distinctly  felt.  The 
follicles  are  not,  however,  developed  sufficiently  for  injection,  until  lactation  has 
commenced.  After  the  cessation  of  the  catamenia  from  age,  so  that  pregnancy  is 
no  longer  possible,  the  lactiferous  ducts  continue  open,  but  the  milk-follicles  are 
incapable  of  receiving  injection.  The  substance  of  the  glandules  gradually  dis- 
appears, so  that  in  old  age  only  portions  of  the  ducts  remain,  which  are  usually 
loaded  with  mucus ;  but  the  place  of  the  glandules  is  commonly  filled-up  by  adi- 
pose tissue,  so  that  the  form  of  the  breast  is  preserved.  Sir  A.  Cooper  notices  a 
curious  change,  which  he  states  to  be  almost  invariable  with  age ;  namely,  the 
ossification  of  the  arteries  of  the  breast,  the  large  trunks  as  well  as  the  branches, 
so  that  their  calibre  is  greatly  diminished  or  even  obliterated. 

918.  The  Mammary  gland  of  the  Male  is  a  sort  of  miniature  picture  of  that  of 
the  Female.     It  varies  extremely  in  its  magnitude;  being  in  some  persons  of  the 
size  of  a  large  pea ;  whilst  in  others  it  is  an  inch,  or  even  two  inches,  in  diam- 
eter.    In  its  structure  it  corresponds  exactly  with  that  of  the  female,  but  is  alto- 
gether formed  on  a  smaller  scale.     It  is  composed  of  lobules  containing  follicles, 
from  which  ducts  arise ;  and  these  follicles  and  ducts  are  not  too  minute  to  be 
injected,  although  with  difficulty.    The  evolution  of  the  gland  goes-on  pari passu 
with  that  of  the  body,  not  undergoing  an  increase  at  any  particular  period ;  it  is 
sometimes  of  considerable  size  in  old  age.     A  fluid,  which  is  probably  mucus, 
may  be  pressed  from  the  nipple  in  many  persons ;  and  this  in  the  dead  body, 
with  even  more  facility  than  in  the  living.     That  the  essential  character  of  the 
gland  is  the  same  in  the  male  as  in  the  female,  is  shown  by  the  instances,  of 
which  there  are  now  several  on  record,  in  which  infants  have  been  suckled  by 
men  (§  919). 

919.  Although  the  state  of  functional  activity  in  the  Mammary  gland  is  usu- 
ally limited  to  the  epoch  succeeding  Parturition,  yet  this  is  not  invariably  the 

•  See  the  valuable  paper  by  Dr.  Peddie,  'On  the  Mammary  Secretion,'  in  the  "  Edinb. 
Mcnthly  Journ.,"  Aug.  1848 


MAMMARY    SECRETION:  —  ITS    COMPOSITION.          817 

ease;  for  numerous  instances  are  on  record,  in  which  young  women  who  have 
never  borne  children,  and  even  old  women  long  past  the  period  of  child-bearing, 
have  had  such  a  copious  flow  of  milk,  as  to  be  able  to  act  as  efficient  nurses.1  In 
these  cases,  the  strong  desire  to  furnish  milk,  and  continued  irritation  of  the 
nipple  by  the  infant's  mouth,  seem  to  have  furnished  the  stimulus  requisite  for 
the  formation  of  the  secretion ;  and  it  has  been  found  that  this  is  usually  ade- 
quate to  restore  the  secretion,  after  it  has  been  intermitted  for  some  months  during 
the  ordinary  period  of  lactation,  in  consequence  of  disorder  or  debility  on  the 
part  of  the  mother,  or  any  other  cause ;  so  that  where  her  condition  renders  it 
advisable  that  she  should  discontinue  nursing  for  a  time,  the  child  may  be  with- 
drawn and  the  milk  l  dried-up/  with  a  confident  expectation  that  the  secretion 
may  be  reproduced  subsequently.2  Dr.  M'Williams  mentions  in  his  Report  of  the 
Niger  Expedition,3  that  the  inhabitants  of  Bona  Vista  (Cape  de  Verde  Islands) 
are  accustomed  to  provide  a  wet-nurse  in  cases  of  emergency,  in  the  person  of  any 
woman  who  has  once  borne  a  child  and  is  still  within  the  age  of  child-bearing,  by 
continued  fomentation  of  the  mammae  with  a  decoction  of  the  leaves  of  thejatro- 
pha  curcas,  and  by  suction  of  the  nipple. — The  most  curious  fact,  however,  is 
that  even  Men  should  occasionally  be  able  to  perform  the  duties  of  nurses,  and 
should  afford  an  adequate  supply  of  infantile  nutriment.  Several  cases  of  this 
kind  are  upon  record ; 4  but  one  of  the  most  recent  and  authentic  is  that  given  by 
Dr.  Dunglison.5  "  Professor  Hall,  of  the  university  of  Maryland,  exhibited  to  his 
Obstetrical  class,  in  the  year  1837,  a  coloured  man,  fifty-five  years  of  age,  who 
had  large,  soft,  well-formed  mammae,  rather  more  conical  than  those  of  the  female, 
and  projecting  fully  seven  inches  from  the  chest;  with  perfect  and  large  nipples. 
The  glandular  structure  seemed  to  the  touch  to  be  exactly  like  that  of  the  female. 
This  man  had  officiated  as  wet  nurse,  for  several  years,  in  the  family  of  his  mis- 
tress ;  and  he  represented  that  the  secretion  of  milk  was  induced  by  applying  the 
children  entrusted  to  his  care,  to  the  breasts,  during  the  night.  When  the  milk 
was  no  longer  required,  great  difficulty  was  experienced  in  arresting  the  secretion. 
His  genital  organs  were  fully  developed. "  Corresponding  facts  are  also  recorded 
of  the  male  of  several  of  the  lower  animals. 

920.  The  secretion  of  Milk  consists  of  Water  holding  in  solution  Sugar,  various 
Saline  ingredients,  and  the  peculiar  albuminous  substance  termed  Casein ;  and 
having  Oleaginous  particles  suspended  in  it.  The  constitution  of  this  fluid  is 
made  evident  by  the  ordinary  processes  to  which  it  is  subjected  in  domestic  eco- 
nomy. If  it  be  allowed  to  stand  for  some  time,  exposed  to  the  air,  the  greater 
part  of  the  oleaginous  globules  come  to  the  surface,  being  of  less  specific  gravity 
than  the  fluid  through  which  they  are  diffused  :  this  is  especially  the  case  with 
the  hrger  facetted  globules,  which  have  been  hence  distinguished  as  cream-glo- 
bule*. The  cream  thus  formed  does  not,  however,  consist  of  oily  particles  alone  ; 
but  includes  a  considerable  amount  of  casein,  with  the  sugar  and  salts  of  the 
milk.  These  are  further  separated  by  the  continued  agitation  of  the  cream  • 

1  \  collection  of  such  cases  is  given  in  Dr.  Dunglison's  "  Human  Physiology,  7th  edit.* 
vo1.  ii.  p..  518. 

3  See  an  account  of  M.  Trousseau's  experience  on  this  point,  in  "L'Union  Me'dicale," 
1852,  No.  7;  and  a  paper  by  Dr.  Ballou  in  the  "  Amer.  Journ.  of  Med.  Sci.,"  Jan.  1852. 

3  "Medical  Gazette,"  Jan.  1847. 

4  See  the  case  described  by  the  "Bishop  of  Cork,  in  the  "  Philosophical  Transactions," 
vol.  xli.  p.  813 :  one  mentioned  by  Sir  John  Franklin  ("  Narrative  of  a  Journey  to  the  Polar 
Sea,"  p.  157);  and  one  which  fell  under  the  notice  of  the  celebrated  traveller  Humboldt 
("  Personal  Narrative,"  vol.  iii.  p.  58). 

5  "  Human  Physiology,"  7th  edit.,  vol.  ii.  p.  514. — Dr.  Dunglison  also  mentions  that  in 
the  winter  of  1849-50,  an  athletic  man,  twenty-two  years  of  age,  presented  himself  at  the 
Jefferson  Medical  College  at  Philadelphia  ;  whose  left  mammae,  without  any  assignable  cause, 
had  become  greatly  developed,  and  secreted  milk  copiously. — It  may  be  added  that  a  lac- 
tescent fluid,  apparently  presenting  the  characters  of  true  milk,  may  frequently  be  ex- 
presse'l  from  the  mammary  glands  of  infants.     (See  "Dublin  Medical  Press,"  April  17, 
1850.) 

52 


818 


OF    GENERATION:  —  LACTATION. 


FIG.  244. 


which,  by  rupturing  the  envelopes  of  the  oil-globules,  separates  it  into  Initter, 
formed  by  their  aggregation,  and  buttermilk,  containing  the  casein,  sugar,  &c. 
A  considerable  quantity  of  casein,  however,  is  entangled  with  the  oleaginous 
matter,  and  this  has  a  tendency  to  decompose,  so  as  to  render  the  butter  rancid ; 
it  may  be  separated  by  keeping  the  butter  melted  at  the  temperature  of  180°, 
when  the  casein  will  fall  to  the  bottom,  leaving  the  butter  pure  and  much  less 
liable  to  change. — The  milk,  after  the  cream  has  been  removed,  still  contains  the 
greatest  part  of  its  casein  and  sugar.  If  it  be  kept  long  enough,  a  spontaneous 
change  takes-place  in  its  composition ;  the  sugar  is  converted  into  lactic  acid,  and 
this  coagulates  the  casein,  precipitating  it  in  small  flakes.  The  same  precipitation 
may  be  accomplished  at  any  time,  by  the  addition  of  an  acid ;  all  the  acids,  how- 
ever, which  act  upon  albumen,  do  not  precipitate  casein,  as  will  presently  be 
pointed-out  in  detail ;  the  most  effectual  is  that  contained  in  the  dried  stomach 
of  a  calf,  known  as  rennet.  The  whey  left  after  the  curd  has  been  separated, 
contains  a  large  proportion  of  the  saccharine  and  saline  matter  that  entered  into 
the  original  composition  of  the  milk ;  this  may  be  readily  separated  by  evaporation. 
921.  When  Milk  is  examined  with  the  Microscope,  it  is  seen  to  contain  a  large 
number  of  particles  of  irregular  size  and  form,  suspended  in  a  somewhat  turbid 
fluid  (Fig.  244) ;  these  particles  vary  in  size  from  about  the  l-12,700th  to  the 
l-3040th  of  an  inch ;  and  they  are  termed  c  milk-globules/  They  are  not  affected 
by  the  mere  contact  of  ether  or  alkalies;  but  if  these  reagents  are  shaken  with 

them,  an  immediate  solution  is  the  re- 
sult. The  same  effect  happens,  if  they 
are  first  treated  with  acetic  acid.  Hence 
it  is  evident  that  the  globules  consist  of 
oily  matter,  inclosed  in  an  envelope  of 
some  kind;  and  an  extremely  delicate 
pellicle  may,  in  fact,  be  distinguished, 
after  the  removal  of  the  oily  matter  by 
ether,  or  after  the  globules  have  been 
ruptured  and  their  contents  pressed-out 
by  rubbing  a  drop  of  milk  between  two 
plates  of  glass.  No  proof  of  the  organi- 
zation of  this  pellicle  has,  however,  been 
detected;  and  it  is  probably  to  be  re- 
garded as  the  simple  result  of  the  con- 
tact of  oil  with  albuminous  matter. — 
Besides  these  milk-globules,  other  glo- 
bules of  much  smaller  size  are  seen  in 
milk;  and  these  present  the  peculiar 
movement  which  is  exhibited  by  mole- 
cules in  general.  Most  of  them  seem 
to  consist  of  oily  matter  not  inclosed  in 

an  envelope,  as  they  are  at  once  dissolved  when  the  fluid  is  treated  with  ether ; 
but,  according  to  the  statements  of  Donne,  it  would  seem  that  a  portion  of  them 
are  composed  of  casein,  suspended,  not  dissolved,  in  the  fluid.  In  addition  to  the 
foregoing  particles,  there  are  found  in  the  Colostrum,  or  milk  first  secreted  after 
delivery,  large  yellow  granulated  corpuscles  (Fig.  244,  a,  a),  which  seem  to  be 
composed  of  a  multitude  of  small  grains  aggregated  together ;  these  appear  to  be 
chiefly  of  a  fatty  nature,  being  for  the  most  part  soluble  in  ether ;  but  traces  of 
some  adhesive  matter,  probably  mucus,  holding-together  the  particles,  are  then 
seen.  They  are  considered  by  some  as  '  exudation-corpuscles/  to  which  they  cer- 
tainly bear  a  close  resemblance ;  according  to  Reinhardt,  they  are  transformations 
of  the  epithelial  cells  of  the  mammary  ducts,  the  result  of  a  sort  of  fatty  degene- 
ration or  regressive  metamorphosis  consequent  upon  the  peculiar  activity  of  the 


Microscopic  appearance  of  Human  Milk,  with 
an  intermixture  of  Colostric  corpuscles  at  a,  a, 
arid  elsewhere. 


COMPOSITION    OF    MAMMARY    SECRETION.  819 

mammary  gland  during  pregnancy.1  Lamella  of  epithelium  are  also  found  in  the 
milk. — All  the  larger  globules  may  be  removed  by  repeated  filtration ;  and  the 
fluid  is  then  nearly  transparent.  This,  in  fact,  is  the  simplest  way  of  separating 
the  oleaginous  from  the  other  constituents  of  the  milk ;  as  but  little  casein  then 
adheres  to  the  former.  The  transparent  fluid  which  has  passed  through  the  filter, 
contains  nearly  the  whole  amount  of  the  casein  of  the  milk  ;  but  even  in  this  fluid 
there  are  found  globules  too  minute  to  be  kept-back  by  the  filter,  whose  chemical 
reactions  mark  them  as  casein. 

922.  We  shall  now  consider  the  chemical  characters  of  each  of  the  foregoing 
ingredients. — The  Oleaginous  matter  of  milk  principally  consists  of  the  ordinary 
components  of  fat  ;  but  it  also  contains  another  substance  peculiar  to  it,  designated 
as  butyrin,  to  which  the  peculiar  smell  and  taste  of  butter  are  due ;  this  yields 
in  saponification  three  volatile  acids,  of  strong  animal  odour,  to  which  Chevreul 
has  given  the  names  of  butyric,  caproic,  and  capric  acids.     These  peculiar  acids 
are  not  only  formed  when  the  butyrin  is  treated  with  alkalies ;  but  are  produced 
by  the  ordinary  decomposition  of  this  principle,  which  is  favoured  by  time  and 
moderate  warmth. — The  Casein  of  Human  milk,  however,  is  usually  said  to  be 
much  less  precipitable  by  acids,  than  is  that  of  the  Cow;  very  commonly  resisting 
the  action  of  the  mineral  acids,  and  even  that  of  the  acetic ;  but  being  always 
coagulated  by  rennet,  though  the  curd  is  long  in  collecting.     On  this  point,  how- 
ever, there  has  been  much  discrepancy  of  statement,  on  which  the  recent  experi- 
ments of  Mr.  Moore2  throw  some  light.     It  appears  from  the  results  obtained  by 
him,  that  Human  Milk  forms  with  most  acids  two  sets  of  compounds,  one  of  them 
soluble  in  water,  the  other  insoluble;  the  latter  being  formed  only  when  the  quan- 
tity of  acid  is  large  in  proportion  to  the  casein.     Thus,  when  two  fluid  ounces  of 
Cow's  milk  were  boiled  with  a  single  drop  of  nitric  acid,  complete  coagulation  of 
the  casein  at  once  took-place :  but  when  two  fluid  drachms  of  Human  milk  were 
treated  in  the  same  manner,  no  coagulation  occurred,  though  the  casein  was  at 
once  thrown-down  by  a  solution  of  ferrocyanide  of  potassium ;  the  same  quantity 
of  milk,  with  five  drops  of  the  acid,  formed  a  coagulum  which  was  not  very  ma- 
nifest until  after  the  lapse  of  five  hours,  but  was  very  complete,  the  serous  fluid 
not  being  found  to  contain  any  casein  by  testing  it  with  ferrocyanide  of  potassium ; 
and  it  required  ten  drops  of  nitric  acid  to  produce  immediate  coagulation. — The 
quantity  of  acid  necessary  to  produce  coagulation  sufficiently  rapid  to  be  immedi- 
ately visible,  will  vary  with  the  amount  of  casein  present  in  the  particular  speci- 
men of  milk,  5  drops  in  some  instances  producing  a  coagulation  as  rapid  as  that 
produced  by  10  drops  in  others.     In  no  specimen  did  Mr.  Moore  fail  to  produce 
coagulation  by  adding  a  sufficiency  of  acid.     Acetic  acid  without  heat  produces 
in  Human  milk  a  slow  separation  of  soft  flaky  coagula ;  but,  when  heat  is  em- 
ployed, a  more  perfect  coagulation  is  produced  by  small,  than  by  large  quantities 
of  this  acid.     Rennet  does  not  seem  to  act  upon  the  casein  of  Human  milk,  un- 
less an  acid  be  also  present.     In  several  of  these  particulars,  as  well  as  in  its 
small  proportional  amount,  the  Casein  of  Ass's  milk  bears  a  closer  resemblance 
to  that  of  Human  milk,  than  does  that  of  the  Cow. — The  Sugar  of  Milk,  which 
may  be  obtained  by  evaporating  whey  to  the  consistence  of  a  syrup,  and  then  set- 
ting it  aside  to  crystallize,  forms  opaque  prisms  or  rhombohedra,  whose  composi- 
tion is  IOC,  8H,  80  +  2HO.     In  many  of  its  properties  it  bears  a  close  resem- 
blance to  Glucose  or  Gelatin-sugar,  into  which-  it  is  readily  converted  by  the 
agency  of  dilute  sulphuric  or  hydrochloric  acid,  or  by  the  acetic  or  citric  acids- 
It  is  readily  made  to  pass  into  the  lactic  and  butyric  fermentation,  by  the  appro- 
priate ferments  ;  but  is  with  difficulty  brought  to  undergo  the  vinous  fermentation 
— The  Saline  matter  contained  in  milk,  appears  to  be  nearly  identical  with  thai 
of  the  blood;  with  a  larger  proportion  of  the  phosphates  of  lime  arid  magnesia, 

1  See  an  abstract  of  his  views  in  the  "  Edinb.  Monthly  Journal,"  Feb.  1848, 
"  "  Dublin  Quarterly  Journal  of  Medical  Science,"  vol.  vii.  p.  280. 


820  OF   GENERATION:  —  LACTATION. 

which  amount  to  2  or  2J  parts  in  1000.  These  phosphates  are  held  in  solution 
chiefly  by  the  casein,  which  seems  to  have  a  power  of  combining  with  them,  even 
greater  than  that  of  albumen  :  the  presence  of  a  mioute  proportion  of  free  alkali 
also  assists  their  solution.  A  small  portion  of  iron  in  the  state  of  phosphate,  to- 
gether with  the  chlorides  of  potassium  and  sodium,  may  also  be  detected  in  milk.1 
923.  The  proportion  of  these  different  constituents  is  liable  to  great  variation, 
from  several  causes.  Thus,  the  whole  amount  of  the  solid  constituents  may  vary 
from  86  to  138-6  parts  in  1000;  the  difference  being  partly  due  to  individual 
constitution,  but  in  great  part,  also,  to  the  amount  and  character  of  the  ingesta. 
The  average  seems  to  be  between  100  and  120  parts.  The  following  are  the  re- 
sults of  the  analyses  of  Simon  ;  the  first  column  being  the  average  of  fourteen  ob- 
servations upon  the  same  woman;  the  second  giving  the  maximum  of  each  ingre- 
dient; and  the  third  the  minimum  : — 

i.  ii.  in. 

Water 883-6  914-0  861-4 

Butter 25-3  54-0  8-0 

Casein 34-3  45-2  19-6 

Sugar  of  Milk  'and  extractive  matters 48-2  62-4  39-2 

Fixed  salts 2-3                2-7  1-6 

It  also  appears  from  the  analyses  of  Simon,  that  the  proportion  of  the  different 
ingredients  is  liable  to  variation,  according  to  the  time  which  has  elapsed  since 
parturition.  The  quantity  of  Casein  is  at  its  minimum  at  the  commencement  of 
lactation,  and  then  gradually  rises  until  it  attains  a  nearly  fixed  proportion.  The 
quantity  of  Sugar,  on  the  contrary,  is  at  its  maximum  at  first,  and  gradually  di- 
minishes. The  amount  of  Butter  (as  appears  from  the  wide  extremes  shown  in 
the  above  tables)  is  more  variable  than  that  of  any  other  constituent. — That  some 
of  the  variations,  moreover,  are  due  to  the  character  of  the  ingesta,  and  others 
to  the  external  temperature,  amount  of  exercise,  and  other  circumstances  affecting 
the  individual,  is  proved  by  the  inquiries  of  Dr.  Playfair  upon  the  Milk  of  the 
Cow.  He  has  shown  that  the  amount  of  butter  depends  in  part  upon  the  quan- 
tity of  oily  matter  in  the  food,  and  in  part  upon  the  amount  of  exercise  which  the 
animal  takes  and  the  warmth  of  the  atmosphere  in  which  it  is  kept :  exercise  and 
cold,  by  increasing  the  respiration,  eliminate  part  of  the  oily  matter  in  the  form 
of  carbonic  acid  and  water;  whilst  rest  and  warmth,  by  diminishing  this  drain, 
favour  its  passage  into  the  milk.  The  proportion  of  Casein,  on  the  other  hand, 
is  increased  by  exercise.  Dr.  Playfair's  experience  on  this  head  seems  to  corres- 
pond with  the  results  of  common  observation  in  Switzerland ;  for  where  the  cattle 
pasture  in  very  exposed  situations,  and  are  obliged  to  use  a  great  deal  of  muscu- 
lar exertion,  the  quantity  of  butter  yielded  by  them  is  very  small,  whilst  the 
cheese  is  in  unusually-large  proportion ;  but  these  same  cattle,  when  stall-fed, 
give  a  large  quantity  of  butter  and  very  little  cheese. 

924.  The  change  which  naturally  takes-place  from  the  condition  of  Colostrum 
to  that  of  true  Milk,  during  the  first  week  of  lactation,  is  a  very  important  one. 
The  Colostrum  has  a  purgative  effect  upon  the  child,  which  is  very  useful  in 
clearing  its  bowels  of  the  meconium  that  loads  them  at  birth ;  and  thus  the 
necessity  of  any  other  purgative  is  generally  superseded.  Occasionally,  however, 
the  colostric  character  is  retained  by  the  milk,  during  an  abnormally  long  period ; 
and  the  health  of  the  infant  is  then  severely  affected.  It  is  important  to  know 
that  this  may  occur,  even  though  the  milk  may  present  the  usual  appearance  of 
the  healthy  secretion ;  but  the  microscope  at  once  detects  the  difference.2  The 
return  to  the  character  of  the  early  milk,  which  has  been  stated  to  take-place 
after  the  expiration  of  about  twelve  months,  seems  to  indicate  that  Nature  de- 
signs the  secretion  no  longer  to  be  encouraged;  the  mother's  milk  cannot  then 

•  Haidlen  in  "  Annalen  der  Chimie  und  Pharmacie,"  band  xlv.,  p.  163. 
Q  See  Donne,  "  Du  Lait,  et  en  particulier  celui  des  Nourrices,"  and  "  Brit  and  For.  Med. 
Review,"  vol.  vi.  p.  181. 


CIRCUMSTANCES     AFFECTING    COMPOSITION    OF    MILK.  821 

be  so  nutritious  to  the  child  as  other  food ; '  and  every  medical  man  is  familiar 
with  the  injurious  consequences  to  which  she  renders  herself  liable,  by  unduly 
prolonging  lactation.2  Cases,  are  not  unfrequent,  however,  in  which  the  secre- 
tion continues  as  long  as  there  is  a  demand  for  it ;  and  sometimes  quite  inde- 
pendently of  this.  It  is  the  habit,  among  some  nations,  to  suckle  the  children 
until  they  are  three  or  four  years  old,  and  to  continue  doing  so  even  though  an- 
other pregnancy  should  intervene ; 3  so  that  the  older  child  is  only  displaced  by 
the  arrival  of  another  infant.  And  it  seems  to  be  chiefly  among  those  who  have 
thus  forcecl  the  mammary  gland  into  a  state  of  unnaturally-persistent  activity, 
that  the  spontaneous  and  irrepressible  flow  continues,  after  the  demand  for  it 
has  ceased.4 

925.  It  is  very  interesting  to  observe  that  Milk  contains  the  three  classes  of 
principles  which  are  required  for  human  food, — the  Albuminous,  the  Oleaginous, 
and  the  Saccharine;  and  it  is  the  only  secreted  fluid  in  which  these  all  exist  to 
any  considerable  amount.     It  is,  therefore,  the  food  most  perfectly  adapted  for 
the  young  animal ;  and  is  the  only  single  article  supplied  by  nature,  in  which 
such  a  combination  exists.     Our  artificial  combinations  will  be  suitable  to  replace 
it,  just  in  proportion  as  they  imitate  its  character;  but  in  none  of  them  can  we 
advantageously  dispense  with  milk,  under  some  form  or  other.     It. should  be 
remembered  that  the  Saline  ingredients  of  milk,  especially  the  phosphates  of 
lime,  magnesia,  and  iron,  have  a  very  important  function  in  the  nutrition  of  the 
infant,  affording  the  material  for  the  consolidation  of  its  bo-nes  and  for  the  pro- 
duction of  its  red   blood-corpuscles;  and  any  fluid  substituted  for  milk,  which 
does  not   contain  these,  is  deficient  in  essential  constituents.     It  is  very  justly 
remarked  by  Dr.  Rees,5  that,  of  all  the  secreted  fluids,  Milk  is  most  nearly  allied 
in  its  composition  to  Blood. 

926.  The  proportion  of  the  different  ingredients  in  the  Milk  of  different  ani- 
mals, is  subject  to  considerable  variation  :  and  this  fact  is  of  much  practical  im- 
portance in  guiding  our  selection,  when  good  Human  milk  cannot  be  conveniently 
obtained  for  the  nourishment  of  an  infant.     The  first  point  to  be  inquired-into, 
is  the  quantity  of  solid  matter  contained  in  each  kind ;  this  may  be  determined 
either  by  evaporation,  or  by  the  specific  gravity  of  the  fluid.     The  Specific  Gra- 
vity of  Human  milk  is  stated  by  Dr.  Rees  (loc.  cit.)  to  vary  between  1030  and 
1035;  others,  however,  have  estimated  it  much  lower.     That  of  the  Cow  appears 
to  be  usually  about  the  same ;  that  of  the  cream,  however,  being  1024,  and  that 
of  the  skimmed-milk  about  1035.     The  variation  will  in  part  depend  (as  in  the 
case  of  the  urine)  upon  the  quantity  of  fluid  ingested,  and  in  part,  it  is  probable, 
upon  the  manner  in  which  the  milk  is  drawn ;  for  it  is  well  known  to  milkers, 
that  the  last  milk  they  obtain  is  much  richer  than  that  with  which  the  udder  is 
distended  at  the  commencement.     The  quantity  of  solid  matter  obtainable  from 
Cow's  Milk  by  evaporation,  seems  to  be  usually  considerably  greater  than  that 
yielded  by  Human  Milk;  and  there  is  also  a  considerable  difference  in  the  rela- 
tive proportions  of  their  ingredients,  there  being  far  more  casein  and  less  sugar 

1  On.  the  whole  subject  of  Infant  Nutrition,  the  Author  would  strongly  recommend  the 
excellent  little  work  of  Dr.  A.  Combe,  formerly  referred-to. 

3  One  of  these,  which  has  particularly  fallen  under  the  Author's  notice,  is  debility  of 
the  retina,  sometimes  proceeding  to  complete  amaurosis:  this,  if  treated  in  time,  is  most 
commonly  relieved  by  discontinuance  of  lactation,  generous  diet,  and  quinine. 

3  See   Erman's  "Travels  in  Siberia"   (translated  by  Cooley),  vol.  ii.  p.  527;  and  the 
"Narrative  of  the  United  States'  Exploring  Expedition,"  vol.  ii.  p.  138. 

4  Thus  Dr.  Green  has  published  ("New  York  Journ.  of  Med.  and  Surg.,"  Sept.  1844'» 
the  case  of  a  lady,  set.  47,  the  mother  of  four  children,  who  had  an  abundant  supply  of 
milk  for  twenty-seven  years  previously.     A  period  of  exactly  four  years  and  a  half  occurred 
between  each  birth;  and  the  children  were  permitted  to  take  the  breast  until  they  were 
running  about  at  play.     At  the  time  when  Dr.  G.  wrote,  she  had  been  nine  years  a  widow, 
and  was  obliged  to  have  her  breasts  drawn  daily,  the  secretion  of  milk  being  so  copious 

*  "  Cyclopeedia  of  Anatomy  and  Physiology,"  Art.  '  Milk.' 


822  OF    GENERATION: — LACTATION. 

in  the  milk  of  the  Cow,  than  in  that  of  the  Human  female.  The  following  table 
exhibits  the  average  proportions  of  the  different  ingredients,  in  the  Milk  of 
various  animals  from  which  that  fluid  is  commonly  obtained;  these  proportions, 
however,  are  liable  to  wide  variations. 

Woman.  Cow.                 Chat.             Sheep.  Jss.  Mare. 

(Simon.)  (Simon.)  (Chevallier.)  (Chevallier.)  (Simon.)  (Luiscius.) 

Water , 890  860              868            856  907  888 

Solids 110  140              132            144  95  112 

Butter 25  38  33  42  12                  8 

Casein 35  68  40  45  16                 16 

Sugar  and  Extractive  48  30  53  50 )  „. 

Fixed  Salts 2  6  6  7£ 

It  appears  from  this,  that,  whilst  the  milk  of  the  Cow,  Goat,  and  Sheep  have  a 
general  correspondence  with  each  other,  those  of  the  Ass  and  Mare  are  fluids  of 
very  dissimilar  character,  containing  a  comparatively  small  proportion  of  casein, 
and  still  less  butter,  but  abounding  in  sugar.  Hence  it  is,  that  they  are  much 
more  disposed  to  ferment  than  other  milk ;  indeed  the  sugar  of  Mare's  milk  is  so 
abundant,  that  the  Tartars  prepare  from  it  a  spirituous  liquor,  to  which  they  give 
the  narne^  of  koumiss.  Although  no  milk  more  nearly  approaches  that  of  the 
Human  female,  in  the  proportion  of  its  ingredients  than  that  of  the  Goat,  its 
casein  forms  a  peculiarly-dense  curd,  which  does  not  suit  the  stomach  of  the  infant, 
besides  which,  the  milk  is  tainted  with  the  peculiar  odour  of  the  animal,  which  is 
more  intense  if  the  individual  be  dark-coloured.  The  milk  of  the  Ass,  though 
differing  in  the  proportion  of  its  ingredients,  seems  to  bear  a  closer  approximation 
in  properties  (§  922).  The  milk  of  the  Cow  will  usually  answer  very  well  for  the 
food  of  the  infant,  if  care  be  taken  to  dilute  it  properly,  according  to  the  age  of 
the  child,  and  to  add  a  little  sugar.  Where  there  is  an  apprehension  of  an  early 
failure  in  the  supply  of  Milk,  the  Author  has  found  it  advantageous  to  commence 
feeding  the  Infant  once  a  day  with  this  mixture,  soon  after  the  first  month ;  the 
number  of  its  meals  may  be  progressively  increased,  until  it  becomes  entirely 
independent  of  its  parent,  without  any  abrupt  transition  ;  and  at  the  same  time 
the  proportion  of  water  and  of  sugar  may  be  diminished  in  accordance  with  the 
natural  change  which  takes  place  in  the  milk  of  the  mother  during  the  progress 
of  lactation  (§  923). 

927.  From  what  has  been  stated  of  the  close  correspondence  between  the  ele- 
ments of  the  Blood  and  those  of  the  Milk,  it  is  evident  that  we  can  scarcely  ex- 
pect to  trace  the  existence  of  the  latter,  as  such,  in  the  circulating  fluid.  To 
what  degree  the  change  in  which  the  elaboration  consists  is  accomplished  in  the 
Mammary  gland,  or  during  the  course  of  the  circulation,  there  is  no  certain 
means  of  ascertaining.  It  is  evident  that  the  secretion  cannot  serve  as  the  channel 
for  the  deportation  of  any  element,  the  accumulation  of  which  would  be  injurious 
to  the  system,  since  it  does  not  occur  in  the  Male  at  all,  and  is  present  in  the  Fe- 
male at  particular  times  only.  Yet  there  is  reason  to  believe  that  if,  whilst  the 
process  is  going-on,  it  be  suddenly  checked,  the  retention  of  the  material  in  the 
blood,  or  the  re-absorption  of  the  secreted  fluid,  is  attended  with  injurious  conse- 
quences. Thus  if,  when  the  milk  is  first  secreted,  the  child  be  not  put  to  the 
breast,  an  accumulation  takes-place,  which,  if  not  relieved,  occasions  great  general 
disturbance  of  the  system.  The  narrowness  of  the  orifices  of  the  milk-tubes  ob- 
structs the  spontaneous  exit  of  the  fluid,  especially  in  primiparae ;  the  reservoirs 
and  ducts  become  loaded ;  further  secretion  is  prevented ;  and  a  state  of  conges- 
tion of  the  vessels  of  the  gland,  tending  to  inflammation,  is  induced.  The  accom- 
panying fever  is  partly  due,  no  doubt,  to  the  local  disturbance ;  but  in  part  also, 
there  seems  reason  to  believe,  to  the  re-absorption  of  the  milk  into  the  blood ;  this 
cannot  but  be  injurious,  since,  although  but  little  altered,  the  constitution  of  milk 
is  essentially  different,  especially  in  regard  to  the  quantity  of  crystallizable  matter 
''sugar)  which  it  contains. — Cases  of  the  vicarious  secretion  of  milk  are  not 


MILK    OF    DIFFERENT    MAMMALS. — VICARIOUS    SECRETION.  823 

numerous;  and  in  no  instance  is  there  any  proof  that  the  elements  of  the  fluid 
were  pre-existent  in  the  blood.  Some  of  the  most  curious  are  those  in  which  it 
has  been  poured-out  from  a  gland  in  the  groin ;  but  it  is  probable  that  this  was 
in  consequence  of  the  existence  of  a  real  repetition,  in  that  place,  of  the  true 
mammary  structure ;  this  being  the  situation  of  the  mammae  in  many  of  the  infe- 
rior animals,  of  which  the  homologues  in  Man  are  usually  undeveloped  ' 

928.  Of  the  quantity  of  Milk  ordinarily  secreted  by  a  good  Nurse,  it  is  diffi- 
cult to  form  a  correct  estimate ; 2  since  that  amount  which  can  be  artificially  drawn, 
affords  no  criterion  of  that  which  is  secreted  at  the  time  of  the  '  draught '  (§  833). 
The  quantity  which  can  be  squeezed  from  either  breast?  at  any  one  time,  and 
which,  therefore,  must  have  been  contained  in  its  tubes  and  reservoirs,  is  about 
two  ounces.     The  amount  secreted  is  greatly  influenced  by  the  mental  and  phy- 
sical condition  of  the  female,  and  also  by  the  quantity  and  character  of  the  in- 
gesta.     In  regard  to  the  influence  of  the  mental  state  upon  this  secretion,  ample 
details  have  already  been  given  (§§  833,  919).     With  respect  to  the  physical 
state  most  favourable  to  the  production  of  an  ample  supply  of  this  important  fluid, 
it  may  be  stated  generally,  that  sound  health,  a  vigorous  but  not  plethoric  consti- 
tution, regular  habits,  moderate  but  not  fatiguing  exercise,  and  an  adequate  but 
not  excessive  amount  of  nutritious  food,  furnish  the  conditions  most  required.    It 
is  seldom  that  stimulating  liquors,  which  are  so  commonly  indulged-in,  are  anything 
but  prejudicial;  and  even  where,  as  sometimes  unquestionably  happens,  an  im- 
provement in  the  condition  both  of  mother  and  infant  is  the  immediate  result  of 
the  moderate  employment  of  them,  it  is  questionable  whether  the  remote  effect  is 
not  of  a  reverse  nature.3     Their  modus  operandi,  when  they  are  really  beneficial, 
seems  to  lie  in  promoting  the  digestive  process,  and  in  thus  aiding  in  the  appro- 
priation of  those  nutritive  materials,  which  constitute  the  real  source  of  the  solid 
constituents  of  the  milk. 

929.  The  influence  of  various  Medicines  upon  the  Milk,  is  another  important 
question  which  has  not  yet  been  sufficiently  investigated.     As  a  general  rule,  it 
appears  that  most  soluble  saline  compounds  pass  into  the  milk  as  into  other  secre- 

1  The  following  is  a  more  unequivocal  case  of  vicarious  secretion ;  and  it  is  peculiarly 
interesting  as  exhibiting  the  injurious  effects  of  the  re-absorption  of  the  secretion,  and  the 
relief  which  the  system  experienced  when  it  was  separated  from  the  blood  by  the  new 
channel.  "  A  lady  of  delicate  constitution  (with  a  predisposition  to  pneumonia)  was  pre- 
vented from  suckling  her  child,  as  she  desired,  by  the  following  circumstance.  Soon  after 
her  delivery  she  had  a  severe  fever,  during  which  her  breasts  became  very  large  and  hard; 
the  nipples  were  swollen  and  firm ;  and  there  was  evidently  an  abundant  secretion  of 
niilk ;  but  neither  the  suckling  of  the  infant,  nor  any  artificial  means,  could  draw  a  single 
drop  of  fluid  from  the  swollen  glands.  It  was  clear  that  the  milk-tubes  were  closed ;  and 
as  the  breasts  continued  to  grow  larger  and  more  painful,  purgatives  and  other  means 
were  employed  to  check  the  secretion  of  milk.  After  three  days,  the  fever  somewhat 
diminished,  and  was  replaced  by  a  constant  cough,  which  was  at  first  dry,  but  soon  after 
was  followed  by  the  expectoration  of  simple  mucus.  After  this,  the  cough  diminished  in 
severity,  and  the  expectoration  became  easy;  but  the  sputa  were  no  longer  mucous,  but 
were  composed  of  a  liquid,  which  had  all  the  physical  characters  of  genuine  milk.  This 
continued  for  fifteen  days ;  the  quantity  of  milk  expectorated  amounting  to  three  ounces 
or  more  in  the  twenty-four  hours.  The  breasts  gradually  diminished  in  size :  and  by  the 
time  that  the  expectoration  ceased,  they  had  regained  their  natural  dimensions.  The  same 
complete  obstacle  to  the  flow  of  milk  from  the  nipples  recurred  after  the  births  of  four  chil- 
dren successively,  with  the  same  sequelae.  After  the  sixth,  she  had  the  same  symptoms 
of  fever,  but  this  time  they  were  not  followed  by  bronchitis  or  the  expectoration  of  milk; 
she  had  in  their  stead  copious  sweatings,  which,  with  other  severe  symptoms,  reduced  her 
to  a  cachectic  state,  and  terminated  fatally  in  a  fortnight."  ("Bulletino  delle  Scienze 
Mediche,"  Apr.,  1839  :  and  "  Brit,  and  For.  Med.  Review,"  Jan.,  1840.)— [See  also  a  case 
reported  by  Dr.  S.  W.  Mitchell,  in  the  "  Amer.  Jour.  Med.  Sci.,"  July,  1855. — ED.] 

a  For  an  estimate  by  M.  Guillot,  founded  on  the  comparative  weight  of  the  Infant  before 
and  after  lactation,  see  "L'Union  Me"dicale,"  3852,  No.  16.  The  total  amount  considered 
by  Mons.  G.  to  be  usually  drawn  in  the  twenty-four  hours,  varies  from  32  oz.  to  64  oz 
(apoth.);  but  his  estimates  are  vitiated  by  the  extraordinary  frequency  of  the  lactations 
observed,  the  infant  being  put  to  the  breast  from  25  to  30  times  in  the  twenty-four  houri. 

8  See  the  Author's  "Physiology  of  Temperance  and  Total  Abstinence,"  g  208. 


824         OF     THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

tionsj  but  there  are  many  exceptions.  Common  salt,  the  sesqui-carbonate  of 
soda,  sulphate  of  soda,  iodide  of  potassium,  oxide  of  zinc,  tris-nitrate  of  bismuth, 
and  sesqui-oxide  of  iron,  have  been  readily  detected  in  the  milk,  when  these 
substances  were  experimentally  administered  to  an  Ass;  and  ordinary  experience 
shows  that  the  Human  infant  is  affected  by  many  of  these,  when  they  are  ad- 
ministered to  the  mother.  The  influence  of  mercurial  medicines  taken  by  the 
mother,  in  removing  from  the  infant  a  syphilitic  taint  possessed  by  both,  is  also 
well  known.  The  vegetable  purgatives,  especially  castor-oil,  senna,  and  colocytith, 
have  little  effect  upon  the  milk ;  hence  they  are  to  be  preferred  to  the  saline 
aperients,  when  it  is  not  desired  to  act  upon  the  bowels  of  the  child. 


CHAPTER  XVII. 

OF    THE    DIFFERENT   BRANCHES    OF   THE     HUMAN     FAMILY,    AND     THEIR 
MUTUAL     RELATIONS. 

1.    General  Considerations. 

930.  AMONGST  the  various  tribes  of  Men,  which  people  the  surface  of  the 
globe,  and  which  are  separated  from  all  other  animals  by  the  characters  formerly 
described  (Chap.  I.),  there  are  differences  of  a  very  striking  and  important  na- 
ture.    They  are  distinguishable  from  each  other,  not  only  by  their  language, 
dress,  manners  and  customs,  religious  belief,  and  other  acquired   peculiarities, 
but  by  the  physical  conformation  of  their  bodies ;  and  the  difference  lies  not 
merely  in  the  colour  of  the  skin,  the  nature  of  the  hair,  the  form  of  soft  parts 
(such  as  the  nose,  lips,  &c.),  but  in  the  shape  of  the  skull,  and  of  other  parts  of 
the  bony  skeleton,  which  might  be  supposed  to  be  less  liable  to  variation.     It  is 
a  question  of  great  scientific  interest,  as  well  as  one  that  considerably  affects  the 
mode  in  which  we  regard  the  races  that  differ  from  our  own,  whether  they  are 
all  of  one  species,  that  is,  descended  from  the  same  or  from  similar  parentage, — 
or  whether  they  are  to  be  considered  as  distinct  species,  the  first  parents  of  the 
several  races  having  had  the  same  differences  among  themselves,  as  those  which 
are  now  exhibited  by  their  descendants. 

931.  In  order  to  arrive  at  a  just  conclusion  on  this  subject,  it  is  necessary  to 
take  a  very  extensive  survey  of  the  evidence  furnished  by  a  number  of  different 
lines  of  inquiry.     Thus,  in  the  First  place,  it  is  right  to  investigate  what  are  the 
discriminating  structural  marks,  by  which  species  are  distinguished  among  other 
tribes  of  animals. — Secondly,  it  should  be  ascertained  to  what  extent  variation 
may  proceed  among  races  which  are  historically  known  to  have  had  a  common 
parentage,  and  what  are  the  circumstances  which  most  favour  such  variations. — 
Thirdly,  the  extreme  variations,  which  present  themselves  among  the  different 
races  of  Men,  should  be  compared  with  those  which  occur  among  tribes  of  ani- 
mals known  to  be  of  the  same  parentage ;  and  it  should  be  questioned,  at  the 
same  time,  whether  the  circumstances  which  favour  the  production  of  varieties 
in  the  latter  case,  are  in  operation  in  the  former. — Fourthly,  where  it  is  impos- 
sible to  trace-back  distinct  races  to  their  origin,  it  is  to  be  inquired  how  far  agree- 
ment in  physiological   and  psychological   peculiarities  may  be  regarded  as  indi- 
cating specific  identity,  even  where  a  considerable  difference  exists  in    bodily 
conformation ;  and   this  test,  if  it  can  be   determined-on,  has  to  be  applied  to 
Man. — Fifthly,  it  must  be  attempted,  by  a  detailed  examination  of  the  varieties 
of  the  Human  race  themselves,  to  ascertain  whether  their  differences  in  confor- 
mation are  constant  j  or  whether  there  are  not  such  occasional  manifestations,  ia 
each  race,  of  a  tendency  to  assume  the  characters  of  others,  as  to  prevent  any 
definite  lines  being  drawn  between  the  several  tribes,  which  together  make-up 


DIFFERENTIAL     CHARACTERS:  —  COLOUR.  825 

the  (supposed)  distinct  species. — An  investigation  so  comprehensive  could  not  be 
followed-out,  even  in  the  most  cursory  manner  that  would  be  consistent  with 
utility,  within  the  limits  of  the  present  work ;  and  no  more  will  be  attempted, 
therefore,  than  an  indication  of  the  principal  points  of  difference  among  the 
several  Races  of  Men,  and  a  statement  of  the  results  of  inquiry  into  their  de- 
gree of  constancy  in  each  of  the  principal  groups  which  they  have  been  thought 
to  mark-out.1 

932.  The  differential  characters  on  which  those  have  relied,  who  have  sought 
to  establish  the  existence  of  a  plurality  of  species  among  Mankind,  are  both 
Anatomico-Physiological  and  Psychological.     Under  the  former  head  rank  the 
Colour  of  the  Skin,  the  texture  of  the  Hair,  and  the  conformation  of  the  bony 
Skeleton,  especially  the  Skull.     The  latter  consist  in  the  superiority  claimed  for 
some  races  over  others,  in  Intellectual  power,  and  in  Moral  and  Religious  capacity. 
The  former  group  will  be  the  one  first  considered. 

933.  The  Colour  of  the  skin  exists  in  the  Epidermis  only;  and  it  depends 
upon  the  admixture  of  pigment-cells  with  the  ordinary  epidermic  cells  (PRINO. 
OF  COMP.  PHYS.,  Am.  Ed.);  all  the  varied  hues  presented  by  the  different  races 
of  men,  being  due  to  the  relative  amount  of  these  cells,  and  to  the  particular 
tint  of  the  pigment  which  they  form.     It  would  be  easy,  by  selecting  well-marked 
specimens  of  each  race,  to  make  it  appear  that  colour  affords  a  character  suffi- 
ciently distinctive  for  their  separation  ;  thus,  for  example,  the  fair  and   ruddy 
Saxon,  the  jet-black  Negro,  the  olive  Mongolian,  and  the  copper-coloured  North 
American,  might  be  considered  to  be  positively  separated  from  each  other  by  this 
character, — propagated,  as  it  seems  to  be,  with  little  or  no  perceptible  change, 
from  generation  to  generation.     But  although  such  might  appear  to  be  the  clear 
and  obvious  result  of  a  comparison  of  this  kind,  yet  a  more  careful  and  compre- 
hensive survey  tends  to  break-down  the  barrier  that  would  be  thus  established. 
For,  on  tracing  this  character  through  the  entire  family  of  Man,  we  find  the  iso- 
lated specimens  just  noticed  to  be  connected  by  such  a  series  of  links,  and  the 
transition  from  one  to  the  other  to  be  so  very  gradual,  that  it  is  impossible  to  say 
where  the  lines  are  to  be  drawn  between  them.     There  is  nothing  here,  then, 
which  at  all  approaches  to  those  fixed  and  definite  marks,  that  are  always  held  to 
be  requisite  for  the  establishment  of  specific  distinctions  among  other  tribes  of 
animals. 

934.  But  further,  there  is  abundant  evidence  that  these  distinctions  are  far 
from  being  constantly  maintained,  even  in  any  one  race.     For  among  all  the  prin- 
cipal subdivisions,  albinoum,  or  the  absence  of  pigment-cells,  occasionally  pre- 
sents itself;  so  that  the  fair  skin  of  the  European  may  present  itself  in  the  off- 
spring of  the  Negro  or  of  the  Red  Man.2     On  the  other  hand,  instances  are  by  no 

1  The  whole   of  this   investigation   has   been   most   elaborately,  and  in   the  Author's 
opinion  most  successfully  worked-out  by  Dr.  Prichard,  in  his  profound  and  philosophical 
Treatise  on  the  "Physical  History  of  Man."     For  a  more  concise  view  of  Dr.  Prichard's 
argument,  with  some  additional  considerations  not  embraced  in  it,  the  Author  may  refer 
to  his  own  Article  on  the  '  Varieties   of  the  Human  Species,'  in  the  "  Cyclop,  of  Anat. 
and  Phys.,"  vol.  iv. — See  also  Dr.  R.  G.  Latham's  "Natural   History  of  the  Varieties  of 
Man;"  and  his  shorter  essay  on  the  'Varieties  of  the  Human  Species,'  in  Orr's  "  Circle 
of  the  Sciences,"  vol.  i. 

2  A  very  curious  example  of  change  of  colour  in  a  Negro,  has  been  recently  recorded  on 
unquestionable  authority. — The  subject  of  it  is  a  negro  slave  in  Kentucky,  set.  45,  who  was 
born  of  black  parents,  and  was  himself  perfectly  black  until  12  years  of  age.     At  that  time, 
a  portion  of  the  skin,  an  inch  wide,  encircling  the  cranium  just  within  the  edge  of  the  hair, 
gradually  changed  to  white  ;  also  the  hair  occupying  that  locality.     A  white  spot  next  ap- 
peared near  the  inner  canthus  of  the  left  eye ;  and  from  this  the  white  colour  gradually 
extended  over  the  face,  trunk,  and  extremities,  until  it  covered  the  entire  surface.     The 
complete  change  from  black  to  white  occupied  about  ten  years ;  and  but  for  his  hair,  which 
was  crisped  or  woolly,  no  one  would  have  supposed  at  this  time  that  his  progenitors  had 
offered  any  of  the  characteristics  of  the  Negro,  his  skin  presenting  the  healthy  vascular 
appearance  of  that  of  a  fair-complexioned  European.     When  he  was  about  22  years  of  age 


826         OF    THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

means  rare,  of  the  unusual  development  of  pigment-cells  in  individuals  of  the  fair- 
skinned  races;  so  that  parts  of  the  body  are  of  a  dark  red  or  brown  hue,  or  are 
even  quite  black.  Such  modifications  may  seem  of  little  importance  to  the  argu- 
ment; since  they  are  confined  to  individuals,  and  may  be  put  aside  as  accidental. 
But  there  is  ample  evidence  that  analogous  changes  may  take  place  in  the  course 
of  time,  which  tend  to  produce  a  great  variety  of  shades  of  colour,  in  the  descend- 
ants of  any  one  stock.  Thus,  in  the  great  Indo-European  family  (part  of  the 
Caucasian  race  of  Blumenbach),  which  may  be  unquestionably  regarded  as  hav- 
ing had  a  common  origin,  we  find  tribes  with  fair  complexion,  yellow  hair,  and 
blue  eyes, — others  presenting  the  xanthous  or  olive  hue, — and  others  decidedly 
black.  A  similar  diversity  may  be  seen  among  the  American  races,  which  are 
equally  referable  to  one  common  stock ;  and  it  exists  to  nearly  the  same  extent 
among  the  African  nations,  which  appear  to  be  similarly  related  to  each  other. 
It  may  be  freely  admitted  that,  among  European  colonists  settled  in  hot  climates, 
such  changes  do  not  present  themselves  within  a  few  generations;  but  in  many 
well-known  instances  of  earlier  colonization,  they  are  very  clearly  manifested. 
Thus  the  wide  dispersion  of  the  Jewish  nation,  and  their  remarkable  isolation 
(maintained  by  their  religious  observances)  from  the  people  among  whom  they 
live,  render  them  peculiarly  appropriate  subjects  for  such  observations;  and  we 
accordingly  find  that  the  brunette  complexion  and  dark  hair,  which  are  usually 
regarded  as  characteristic  of  that  race,  are  frequently  superseded,  in  the  Jews  of 
Northern  Europe,  by  red  or  brown  hair  and  fair  complexion ;  whilst  the  Jews 
who  settled  in  India  some  centuries  ago,  hare  become  as  dark  as  the  Hindoos 
around  them. 

935.  The  relation  of  the  complexions  of  the  different  races  of  Men  to  the  cli- 
mates they  respectively  inhabit,  is  clearly  established  by  an  extended  comparative 
survey  of  both.  From  such  a  survey  the  conclusion  is  inevitable,  that  the  inter- 
tropical  region  of  the  earth  is  the  principal  seat  of  the  darkest  races  of  Men ; 
whilst  the  region  remote  from  the  tropics  is  that  of  the  fairer  races;  and  that  the 
climates  approaching  the  tropics  are  generally  inhabited  by  nations  which  are  of 
an  intermediate  complexion.  To  this  observation  it  may  be  added,  that  high 
mountains,  and  countries  of  great  elevation,  are  generally  inhabited  by  people  of 
a  lighter  colour  than  are  those  of  which  the  level  is  low,  such  as  swampy  or  sandy 
plains  upon  the  sea-coast.  These  distinctions  are  particularly  well  seen  in  Africa, 
where  the  tropics  almost  exactly  mark-out  the  limits  of  the  black  complexion  of 
the  inhabitants;  and  where  the  deepest  hue  is  to  be  seen  among  the  Negroes  of 
the  Guinea  Coast,  whose  residence  unites  both  the  conditions  just  mentioned ; 
whilst  the  mountainous  regions  in  their  immediate  vicinity  are  inhabited  by  tribes 
of  a  much  lighter  aspect. 

936.  The  nature  of  the  Hair  is,  perhaps,  one  of  the  most  permanent  character- 
istics of  different  races.  In  regard  to  its  colour,  the  same  statements  apply,  as 
those  just  made  with  respect  to  the  colour  of  the  skin;  the  variety  of  hue  being 
given  by  pigment-cells,  which  may  be  more  or  less  developed  under  different  cir- 
cumstances. But  it  has  been  thought  that  its  texture  afforded  a  more  valid  ground 
of  distinction  ;  and  it  is  commonly  said,  that  the  substance  which  grows  on  the 
head  of  the  African  races,  and  of  some  other  dark-coloured  tribes  (chiefly  inha- 
biting tropical  climates),  is  woof,  and  not  hair.  This,  however,  is  altogether  a 
mistake ;  for  microscopic  examination  clearly  demonstrates,  that  the  hair  of  the 
Negro  has  exactly  the  same  structure  with  that  of  the  European  ;  and  that  it  does 

however,  dark  copper-coloured  or  brown  spots  began  to  appear  on  the  face  and  hands;  but 
these  have  remained  limited  to  the  portions  of  the  surface  exposed  to  light.  About  the 
time  that  the  black  colour  of  his  skin  began  to  disappear,  he  completely  lost  his  sense  of 
smell  (g  743  note) ;  and  since  he  has  become  white,  he  has  had  measles  and  hooping-cough 
a  second  time.  (See  Dr.  Hutchinson's  account  of  this  case,  in  the  "Amer.  Journ.  of  Med. 
Sci.,"  Jan.  1852.) — A  case  of  partial  disappearance  of  the  black  colour  of  the  Negro's 
Skiu  -was  brought  by  Dr.  Inman  before  the  Zoological  Section  of  the  British  Association 
at.  Liverpool,  Sept.  1854. 


DIFFERENTIAL   CHARACTERS:  —  FORM    OF   SKULL.     827 

not  bear  any  resemblance  to  wool,  save  in  its  crispness  and  tendency  to  curl. 
Moreover,  even  this  character  is  far  from  being  a  constant  one ;  for,  whilst  Euro- 
peans are  not  unfrequently  to  be  met  with,  whose  hair  is  nearly  as  crisp  as  that 
of  the  Negro,  there  is  a  great  variety  amongst  the  Negro  races  themselves,  which 
present  every  gradation  from  a  completely-crisp  (or  what  is  termed  woolly)  hair, 
to  merely  curled  or  even  flowing  locks.1  A  similar  observation  holds  good  in  re- 
gard to  the  natives  of  the  islands  of  the  great  Southern  Ocean,  where  some  indi- 
viduals possess  crisp  hair,  whilst  others,  of  the  same  race,  have  it  merely  curled. 
— It  is  evident,  then,  that  no  characters  can  be  drawn  from  the  colour  or  texture 
of  the  hair  in  Man,  sufficiently  fixed  and  definite  to  serve  for  the  distinction  of 
races ;  and  this  view  is  borne-out  by  the  evident  influence  of  climate,  in  producing 
changes  in  the  hairy  covering  of  almost  every  race  of  domestic  animals ;  such 
changes  often  manifesting  themselves  in  the  very  individuals  that  have  been  trans- 
ported from  one  country  to  another,  and  yet  more  distinctly  in  succeeding  gene- 
rations. 

937.  It  has  been  supposed  that  varieties  in  the  configuration  of  the  Skeleton 
would  afford  characters  for  the  separation  of  the  Human  races,  more  fixed  and 
definite  than  those  derived  from  differences  in  the  form,  colour,  or  texture  of  the 
soft  parts  which  clothe  it;  and  attention  has  been  particularly  directed  to  the 
skull  and  the  pelvis,  as  affording  such  characters.     It  has  been  generally  laid- 
down  as  a  fundamental  principle,  that  all  those  nations  which  are  found  to  re- 
semble each  other  in  the  shape  of  their  heads,  must  needs  be  more  nearly  related 
to  each  other,  than  they  are  to  tribes  of  Men  which  differ  from  them  in  this  par- 
ticular.    But  if  this  principle  be  rigorously  carried-out,  it  will    tend  to  bring 
together  races  which  inhabit  parts  of  the  globe  very  remote  from  each  other,  and 
which  have  no  other  mark  of  affinity  whatever ;  whilst,  on  the  other  hand,  it  will 
often  tend  to  separate  races  which  every  other  character  would  lead  us  to  bring 
together.     It  is  to  be  remembered,  moreover,  that  the  varieties  in  the  conforma- 
tion of  the  skeleton,  presented  by  the  breeds  of  domesticated  animals,  are  at  least 
equal  to  those  which  are  manifested  in  the  conformation  and  colour  of  their  soft 
parts;  and  we  might  reasonably  expect,  therefore,  to  meet  with  similar  variations 
among  the  Human  races.     It  is  probable,  however,  that  climate  has  not  so  much 
influence  in  producing  such  changes  in  the  configuration  of  the  body,  as  the  pecu- 
liar habits  and  mode  of  life  of  the  different  races;  and,  Dr.  Prichard  has  pointed- 
out  a  very  remarkable  relation  of  this  kind,  in  regard  to  the  three  principal  types 
of  form  presented  by  the  skull. 

938.  Among  the  rudest  tribes  of  Men,  hunters  and  savage  inhabitants  of  forests, 
dependent  for  their  supply  of  food  on  the  accidental  produce  of  the  soil  or  on  the 
chase, — among  whom  are  the  most  degraded  of  the  African  nations,  and  the  Aus- 
tralian savages, — a  form  of  head  is  prevalent,  which  is  most  aptly  distinguished  bj 
the  term  prognathous,  indicating  a  prolongation  or  forward-extension  of  the  jaws 
(Fig.  245).     This  character  is  most  strongly  marked  in  the  Negroes  of  the  Gold 
Coast,  whose  skulls  are  usually  so  formed  as  to  give  the  idea  of  lateral  compres- 
sion.    The  temporal  muscles  have  a  great  extent,  rising  high  on  the  parietal 
bones ;    the  cheek-bones  project   forward,  and  not   outward ;  the  upper  jaw  is 
lengthened  and    projects    forwards,  giving  a  similar  projection  to  the  alveolar 
ridge  and  to  the  teeth;  and  the  lower  jaw  has  somewhat  of  the  same  oblique  pro- 
jection, so  that  the  upper  and  lower  incisor  teeth  are  set  at  an  obtuse  angle  to 
each  other,  instead  of  being  nearly  in  parallel  planes,  as  in  the  European.     From 
the  shape  of  the  upper  jaw  alone,  would  result  a  marked  diminution  in  the  facial 
angle,  measured  according  to  the  method  of  Camper;  but  this  diminution  is  far 

'It  is  a  very  common  mistake,  especially  in  the  United  States,  to  consider  Negro  aa 
synonymous  with  African.  So  far  is  this  from  being  the  fact,  that,  as  Dr.  Latham  justly 
remarks,  "the  true  Negro  area,  the  area  occupied  by  men  of  the  black  skin,  thick  lips, 
and  woolly  hair,  is  exceedingly  small ;  as  small  in  proportion  to  the  rest  of  the  continent, 
as  the  area  of  the  district  of  the  stunted  Hyperboreans  is  in  Asia,  or  that  of  the  Lapps  in 
Europe."  (See  %  955,  956.) 


828    OF  THE  BRANCHES  OF  THE  HUMAN  FAMILY. 

from  being  sufficient  to  approximate  the  Ethiopian  races  to  the  higher  Apes,  as 
some  have  supposed  it  to  be  (§  8).     Independently  of  the  diminution  of  the  facial- 

FIG.  245. 


Profile  and  basal  views  of  the  Prognathous  Skull  of  a  Negro. 

angle,  resulting  from  the  projection  of  the  upper  jaw,  it  is  quite  certain  that,  in 
the  typical  prognathous  skull,  there  is  a  want  of  elevation  of  the  forehead;  but  it 
does  not  appear  that  there  is  a  corresponding  diminution  in  the  capacity  of  the 
cranial  cavity,  the  retreating  form  of  the  forehead  being  partly  due  to  the  general 
elongation  of  the  skull  in  the  antero-posterior  direction.  Nor  is  it  true,  as  stated 
by  some,  that  the  position  of  the  foramen  magnum  in  the  Negro  is  decidedly  be- 
hind that  which  it  holds  in  the  European,  in  this  respect  approaching  that  of  the 
Apes  (§  2)  :  since,  if  due  allowance  be  made  for  the  projection  of  the  upper  jaw, 
this  aperture  is  found  to  have  the  same  position  in  the  prognathous  skull  as  in  the 
oval  one,  namely,  exactly  behind  the  transverse  line  bisecting  the  anterc-posterior 
diameter  of  the  base  of  the  cranium.  The  prognathous  skull  is  further  remark- 
able for  the  large  development  of  the  parts  connected  with  the  organs  of  sense,  espe- 
cially those  of  smell  and  hearing.  The  aperture  of  the  nostrils  is  very  wide,  and 
the  internal  space  allowed  for  the  distribution  of  the  olfactory  nerve,  is  much 
larger  than  in  most  European  heads;  the  posterior  openings  of  the  nasal  cavity 
are  not  less  remarkable  for  their  width,  than  the  anterior.  The  external  auditory 
meatus  is  also  peculiarly  wide  and  spacious;  and  the  orbital  cavities  have  been 
thought  to  be  of  more  than  ordinary  capacity, — but  this  last  is  by  no  means  a 
constant  character. 

939.  A  second  type  of  cranial  conformation,  very  different  from  the  preceding, 
belongs  principally  to  the  Nomadic  races,  who  wander  with  their  herds  and  flocks 
over  vast  plains ;  and  to  the  tribes  who  creep  along  the  shores  of  the  Icy  Sea,  and 
live  partly  by  fishing,  and  in  part  on  the  flesh  of  their  reindeer.  This  form,  desig- 
nated by  Dr.  Prichard  as  the  pyramidal  (Fig.  246),  is  typically  exhibited  by 
various  nations  of  Northern  and  Central  Asia;  and  is  seen,  in  an  exaggerated 
degree,  in  the  Esquimaux.  Its  most  striking  character  is  the  lateral  or  outward 
projection  of  the  zygoma,  which  is  due  to  the  form  of  the  malar  bones.  These  do 
not  project  forwards  and  downwards  under  the  eyes,  as  in  the  prognathous  skull ; 
but  take  a  lateral  or  outward  direction,  forming,  with  the  zygomatic  process  of 
the  temporal  bone,  a  large  rounded  sweep  or  segment  of  a  circle.  From  this,  in 
connection  with  the  narrowness  of  the  forehead,  it  results,  that  lines  drawn  from 
the  zygomatic  arches,  touching  the  temples  on  either  side,  instead  of  being  parallel 
(as  in  Europeans),  meet  over  the  forehead,  so  as  to  form  with  the  basis  a  trian- 
gular figure.  The  upper  part  of  the  face  being  remarkably  flat,  the  nose  also 
being  flat,  and  the  nasal  bones,  as  well  as  the  space  between  the  eyebrows,  being 


DIFFERENTIAL    CHARACTERS: — FORM    OF    SKULL.    829 


nearly  on  the  same  plane  with  the  cheek-bones,  the  triangular  space  bounded  by 
these  lines  may  be  compared  to  one  of  the  faces  of  a  pyramid.     The  orbits  are 


FIG.  246. 


FIG.  247. 


Front  and  basal  views  of  the  Pyramidal  Skull  of  an  Esquimaux. 

large  and  deep ;  and  the  peculiar  conformation  of  the  bones  which  surround  it, 
gives  to  the  aperture  of  the  lids  an  appearance  of  obliquity, — the  inner  angle 
seeming  to  be  directed  downwards.  The  whole  face,  instead  of  presenting  an 
oval  form,  as  in  most  Europeans  and  Africans,  is  of  a  lozenge-shape.  The 
greater  relative  development  of  the  zygomatic  bones,  and  of  the  bones  of  the  face 
altogether,  when  compared  with  the  capacity  of  the  cranium,  indicates  in  the 
pyramidal  skull,  a  more  ample  extension  of  the  organs  subservient  to  sensation ; 
the  same  effect  being  thus  produced  by  lateral  expansion,  as  by  the  forward  exten- 
sion of  the  facial  bones  in  the  prognathous  skulls. 

940.  The  most  civilized  races,  —  those  which  live  by  agriculture  and  the  arts 
of  cultivated  life,  —  all  the  most  intellec- 
tually-improved nations  of  Europe  and 
Asia,  —  have  a  shape  of  the  head  which 
differs  from  both  the  preceding,  and  which 
may  be  termed  oval  or  elliptical.  This 
at  once  approves  itself  as  a  more  sym- 
metrical form  j  no  part  having  an  exces- 
sive prominence;  whilst,  on  the  other 
hand,  there  is  nowhere  an  appearance  of 
undue  flattening  or  compression.  The 
head  is  altogether  of  a  rounder  shape 
than  in  the  other  varieties,  and  the  fore- 
head is  more  expanded ;  while  the  max- 
illary bones  and  the  zygomatic  arches  are 
so  formed,  as  to  give  the  face  an  oval 
shape,  nearly  on  a  plane  with  the  fore- 
head and  cheek-bones,  and  not  projecting 
towards  the  lower  part.  Owing  to  the 
more  perpendicular  direction  of  the  alveo- 
lar processes,  the  front  teeth  are  fixed  in  planes  which  are  nearly  or  quite  parallel 
to  each  other.  The  principal  features  in  this  form  of  cranium  are  thus  of  a 
negative  character;  the  chief  positive  distinction  is  the  large  development  of  the 
cranial  cavity,  and  especially  the  fulness  and  elevation  of  the  forehead,  in  pro- 
portion to  the  size  of  the  face ; — indicating  the  predominance  of  the  intellectual 
powers,  over  those  merely  instinctive  propensities  which  are  more  directly  con- 
nected with  sensations.  Among  European  nations,  the  Greeks  have  probably 


Oval  Skull  of  a  European. 


830         OF    THE    BRANCHES     OF    THE    HUMAN    FAMILY. 

displayed  the  greatest  symmetry  and  perfection  in  the  form  of  the  head ;  but 
various  departures  may  be  traced  towards  the  preceding  forms,  when  we  compare 
the  crania  of  different  races,  and  even  of  individuals,  belonging  to  the  same 
stock,  —  some  approaching  the  pyramidal  form  of  the  Northern  Asiatics,  whilst 
others  approximate  to  the  prognathous  type  of  the  Negro. 

941.  The  influence  of  habits  of  life,  continued  from  generation  to  generation, 
upon  the  form  of  the  head,  is  remarkably  evinced  by  the  transition  from  one 
type  to  another,  which  may  be  observed  in  nations  that  have  undergone  a  change 
in  their  manners  and  customs,  and  have  made  an  advance  in  civilization.  Thus, 
to  mention  but  one  instance,  the  Turks  at  present  inhabiting  the  Ottoman  and 
Persian  empires,  are  undoubtedly  descended  from  the  same  stock  with  those 
nomadic  races  which  are  still  spread  through  Central  Asia  (§  953).  The  former, 
however,  having  conquered  the  countries  which  they  now  inhabit,  eight  centuries 
since,  have  gradually  settled-down  to  the  fixed  and  regular  habits  of  the  Indo- 
European  race,  and  have  made  corresponding  advances  in  civilization ;  whilst 
the  latter  have  continued  their  wandering  mode  of  life,  and  can  scarcely  be  said 
to  have  made  any  decided  advance  during  the  same  interval.  Now  the  long  since- 
civil-ized  Turks  have  undergone  a  complete  transformation  into  the  likeness  of 
Europeans ;  whilst  their  nomadic  relatives  retain  the  pyramidal  configuration  of 
the  skull  in  a  very  marked  degree.  Some  have  attributed  this  change  in  the 
physical  structure  of  the  Turkish  race,  to  the  introduction  of  Circassian  slaves 
into  the  harems  of  the  Turks;  but  this  could  only  affect  the  opulent  and  power- 
ful amongst  the  race ;  and  the  great  mass  of  the  Turkish  population  have  always 
intermarried  among  themselves.  The  difference  of  religion  and  manners  must 
have  kept  them  separate  from  those  Greeks  whom  they  subdued  in  the  new  Otto- 
man countries ;  as  in  Persia,  the  Tajiks,  or  real  Persians,  still  remain  quite  dis- 
tinct from  their  Turkish  rulers,  belonging  to  a  different  sect  among  the  Mussul- 
mans, and  commonly  living  apart  from  them.  —  In  like  manner,  even  the  Negro 
head  and  face  may  become  assimilated  to  the  European,  by  long  subjection  to 
similar  influences ;  thus,  in  some  of  our  older  West  Indian  Colonies,  it  is  not  un- 
common to  meet  with  Negroes,  the  descendants  of  those  first  introduced  there, 
who  exhibit  a  very  European  physiognomy ;  and  it  has  even  been  asserted  that  a 
Negro  belonging  to  the  Dutch  portion  of  Guiana  may  be  distinguished  from  an- 
other belonging  to  the  British  settlements,  by  the  similarity  of  the  features  and 
expression  of  each,  to  those  which  respectively  characterize  his  masters.  The 
effect  could  not  be  here  produced  by  the  intermixture  of  bloods,  since  this  would 
be  made  apparent  by  alteration  of  colour. — But  not  only  may  the  pyramidal  and 
prognathous  types  be  elevated  towards  the  elliptical;  the  elliptical  may  be 
degraded  towards  either  of  these.  Want,  squalor,  and  ignorance,  have  a  special 
tendency  to  induce  that  diminution  of  the  cranial  portion  of  the  skull,  and  that 
increase  of  the  facial,  which  characterize  the  prognathous  type ;  as  cannot  but  be 
observed  by  any  one  who  takes  an  accurate  and  candid  survey  of  the  condition 
of  the  most  degraded  part  of  the  population  of  the  great  towns  of  this  country, 
but  as  is  seen  to  be  pre-eminently  the  case  with  regard  to  the  lowest  classes  of 
Irish  immigrants.1  A  certain  degree  of  retrogression  to  the  pyramidal  type,  is 
lalso  to  be  noticed  among  the  nomadic  tribes  which  are  to  be  found  in  every  civil- 
ized community.  Among  these,  as  has  been  remarked  by  a  very  acute  observer,3 
"  According  as  they  partake  more  or  less  of  the  purely  vagabond  nature,  doing 
nothing  whatsoever  for  their  living,  but  moving  from  place  to  place,  preying  on 
the  earnings  of  the  more  industrious  portion  of  the  community,  so  will  the  attri- 
butes of  the  nomade  races  be  found  more  or  less  marked  in  them;  and  they  are 
all  more  or  less  distinguished  for  their  high  cheek-bones  and  protruding  jaws ;" 
thus  showing  that  kind  of  mixture  of  the  pyramidal  with  the  prognathous  type, 
whVto  is  to  be  seen  among  the  lowest  of  the  Indian  and  Malayo-Polynesian  races. 

1  See  the  "Dublin  University  Magazine,"  No.  xlviii. 
Mr   Henry  Mayhew.  in  "  London  Labour  and  the  London  Poor,"  p.  2. 


DIFFERENTIAL   CHARACTERS: — FORM    OF    PELVIS   AND   LIMBS.      831 

942.  Next  to  the  characters  derived  from  the  form  of  the  head,  those  which 
are  founded  upon  the  form  of  the  pelvis  seem  entitled  to  rank.     These  have  been 
particularly  examined  by  Professors  Vrolik  and  Weber.     The  former  was  led  by 
his  examinations  of  this  part  of  the  skeleton,  to  consider  that  the  pelvis  of  the 
Negress,  and  still  more  that  of  the  female  Hottentot,  approximates  to  that  of  the 
Simige  in  its  general  configuration  •  especially  in  its  length  and  narrowness, — the 
iliac  bones  having  a  more  vertical  position,  so  that  the  anterior  spines  approach 
one  another  much  more  closely  than  they  do  in  the  European ;  and  the  sacrum 
also  being  longer  and  narrower.     On  the  other  hand,  Prof.  Weber1  concludes, 
from  a  more  comprehensive  survey,  that  no  particular  figure  is  a  permanent  cha- 
racteristic of  any  one  race.     He  groups  the  principal  varieties  which  he  has  met- 
with,  according  to  the  form  of  the  upper  opening,  into  oval,  round,  four-sided, 
and  wedge-shaped.     The  first  of  these  is  most  frequent  in  the  European  races ; 
the  second,  among  the  American  races ;  the  third,  most  common   among  the 
Mongolian  nations,  corresponds  remarkably  with  their  form  of  head ;  whilst  the 
last  chiefly  occurs  among  the  races  of  Africa,  and  is  in  like  manner  conformable 
with  the  oblong  compressed  form  usually  presented  by  their  cranium.     But  al- 
though there  are  particular  shapes  which  are  most  prevalent  in  each  race,  yet 
there  are  numerous  individual  deviations,  of  such  a  nature  that  every  variety  of 
form  presents  itself  occasionally  in  any  given  race. 

943.  Other  variations  have  been  observed  by  anatomists,  between  the  different 
races  of  Man,  in  the  relative  length  of  the  bones,  and  in  the  shape  of  the  limbs ; 
but  these  also  seem  to  have  reference  to  the  degree  of  civilization,  and  to  the  re- 
gularity of  the  supply  of  wholesome  nutriment.     It  is  generally  to  be  observed 
that  the  races  least  improved  by  civilization,  like  the  uncultivated  breeds  of  ani- 
mals, have  slender,  lean,  and  elongated  limbs ;  this  may  be  especially  remarked 
in  the  natives  of  Australia.     In  nearly  all  the  less  civilized  races  of  Man,  the 
limbs  are  more  crooked  and  badly-formed  than  the  average  of  those  of  Europeans ; 
and  this  is  particularly  the  case  in  the  Negro,  the  bones  of  whose  legs  bow  out- 
wards, and  whose  feet  are  remarkably  flat.     It  has  been  generally  believed,  that 
the  length  of  the  fore-arm  in  the  Negro  is  so  much  greater  than  in  the  European, 
as  to  constitute  a  real  character  of  approximation  to  the  Apes.     The  difference, 
however,  is  in  reality  extremely  slight ;  and  is  not  at  all  comparable  with  that 
which  exists  between  the  most  uncultivated  races  of  Men  and  the  highest  Apes 
(§  5).     And  in  regard  to  all  the  peculiarities  here  alluded-to,  it  is  to  be  observed, 
that  they  can  only  be  discovered  by  the  comparison  of  large  numbers  of  one  race 
with  corresponding  numbers  of  another;  for  individuals  are  found  in  every  tribe, 
possessing  the  characters  which  distinguish  the  majority  of  the  other  race.     Such 
peculiarities,  therefore,  are  totally  useless  as  the  foundation  of  specific  characters  $ 
being  simply  variations  from  the  ordinary  type,  resulting  from  causes  which  might 
affect  the  entire  race,  as  well  as  individuals.  —  The  connection  between  the  gene- 
ral form  of  the  body,  on  the  one  hand,  and  the  degree  of  civilization  (involving 
the  regular  supply  of  nutriment)  on  the  other,  is  made  apparent,  not  merely  by 
the  improvement  which  we  perceive  in  the  form,  development,  and  vigour  of  the 
frame,  as  we  advance  from  the  lowest  to  the  most  cultivated  of  the  Human  races; 
but  also  by  the  degradation  that  is  occasionally  to  be  met-with  in  particular  groups 
of  the  higher  tribes,  which  have  been  subjected  for  several  generations  to  the  in- 
fluence of  depressing  causes.     Of  such   degradation,  occurring  under  circum- 
stances that  permit  its  successive  steps  to  be  traced,  we  have  a  remarkable 
example  in  the  conversion  of  certain  tribes  of  the  Hottentot  race  into  Bushmen 
(§  958);  and, there  is  very  strong  ground  for  the  belief,  that  similar  influences 
have  operated  at  a  more  remote  period,  in  the  production  of  the  peculiar  charac- 
ters of  the  Guinea-coast  Negroes  and  Australian  Bushmen. 

944.  Independently,  however,  of  the  obvious  modifying  influence  of  external 

1  "Die  Lehre  von  den  Ur-  tmd  Racenformen  der  Schaedel  und  Becken  des  Menschen," 
Dusseldcrf.  1830. 


832         OF    THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

circumstances,  much  allowance  must  be  made  for  that  tendency  fo  variation, 
which  presents  itself,  more  or  less,  in  all  those  races  of  animals,  which  possess 
such  a  constitutional  capability  of  adaptation  to  changes  in  climate,  habits  of  life, 
&c.,  as  enables  them  to  live  and  flourish  under  a  variety  of  conditions.  Thus  we 
find  that  the  offspring  of  any  one  pair  of  domesticated  animals  do  not  all  precisely 
agree  among  themselves,  or  with  their  parents,  either  in  bodily  conformation,  or 
in  psychical  character  j  but  that  individual  differences,  as  they  are  termed,  exist 
among  them.  Now,  as  this  tendency  to  variation  cannot  be  clearly  traced  to  any 
influence  of  external  circumstances,  it  is  commonly  distinguished  by  the  term 
'spontaneous/  but  as  there  is  no  effect  without  a  cause,  and  as  the  widest  dif- 
ferences of  this  kind  present  themselves  in  those  races  which  are  most  obviously 
amenable  to  the  influence  of  external  conditions,  we  seem  justified  in  attributing 
them  to  agencies  operating  unostensibly  upon  the  parents,  either  previously  to 
their  intercourse,  or  at  the  time  of  coition  (§  880),  or  in  the  female  during  the 
period  of  utero-gestation  (§  883).  The  difference  between  wild  and  domesticated 
animals  in  regard  to  colour  affords  a  very  good  illustration  of  this  general  fact; 
for  the  uniformity  among  the  former  is  no  less  remarkable  than  the  want  of  con- 
stancy among  the  latter;  and  whilst  variety  of  colour  soon  gives-place  to  urii- 
formity,  when  domesticated  races  return  in  any  considerable  degree  towards  their 
primitive  state,1  it  very  speedily  developes  itself  in  races  which  are  undergoing 
the  converse  process.2 

945.  Now  it  is  by  taking  advantage  of  those  l  spontaneous '  departures  from  the 
ordinary  type,  which  present  features  of  value  to  the  breeders  of  domesticated 
animals,  that  new  races  are  developed  from  time  to  time  among  these;  any 
strongly-marked  peculiarity  which  thus  appears  in  only  a  single  individual,  being 
usually  transmitted  to  some  of  its  offspring,  and  being  almost  certainly  perpetu- 
ated when  both  parents  are  distinguished  by  it,  as  happens  when  the  products  of 
the  first  procreation  become  capable  of  breeding  with  each  other.3 — Now  there 
can  be  no  hesitation  in  admitting,  that  the  tendency  to  the  so-called  (  spontane- 
ous' variation  prevails  in  the  Human  race  to  a  greater  degree  than  in  any  other; 
since  we  find  most  remarkable  diversities  in  features,  complexion,  hair,  and  gene- 
ral conformation,  among  the  offspring  of  the  same  parentage  ;  whilst  more  special 
modifications  of  the  ordinary  type,  such  as  the  possession  of  six  fingers  on  each 
hand  and  of  six  toes  on  each  foot,  are  of  no  unfrequent  occurrence.  Under 
ordinary  circumstances,  these  modifications  tend  to  disappear  as  often  as  they 
occur;  the  free  intermixture  of  those  members  of  the  race  which  possess  them, 
with  those  which  depart  less  from  the  ordinary  type,  tending  to  merge  them  in 
the  general  average.  But  there  can  be  no  reasonable  doubt,  that  if  the  same 
kind  of  segregation  were  practised  among  Mankind,  which  is  adopted  by  the 
breeders  of  animals  for  the  purpose  of  perpetuating  a  particular  variety, — if,  for 

1  This  has  been  especially  noticed  in  the  dogs,  horses,  cattle,  sheep,  and  hogs,  introduced 
by  the  Spaniards  into  South  America. 

3  Thus  Mr.  T.  Bell  informs  us  ("  British  Quadrupeds,"  2d  edit,  p.  203),  that  an  Austra- 
lian bitch,  or  dingo,  in  the  Zoological  Gardens,  had  a  litter  of  puppies,  the  father  of  which 
•was  also  of  that  breed ;  both  parents  had  been  taken  in  the  wild  state ;  both  were  of  the 
uniform  reddish-brown  colour  which  belongs  to  the  race,  and  the  mother  Lad  never  bred 
before ;  but  the  young,  generated  in  confinement,  and  in  a  half-domesticated  state,  were 
all  more  or  less  spotted. 

3  See  the  history  of  the  introduction  of  the  ancon  breed  of  sheep,  characterized  by  a 
peculiar  conformation  of  its  limbs,  in  Massachusetts,  given  by  Col.  Hutchinson  in  the 
"  Phil.  Trans."  for  1813. — A  similar  account  has  been  more  lately  given  by  Prof.  Owen 
(in  a  Lecture  delivered  before  the  Society  of  Arts,  Dec.  10,  1851),  respecting  the  recent 
introduction  of  a  new  breed  of  merino  sheep,. distinguished  for  the  long,  smooth,  straight, 
and  silky  character  of  the  wool,  and  now  known  as  the  Mauchamp  breed. — In  both  in- 
stances, the  breed  originated  in  the  spontaneous  appearance  of  a  male  lamb  possessing 
the  peculiarities  in  question  ;  from  its  offspring  such  a  selection  was  mnde  by  the  breeder, 
as  enabled  him  to  bring  together  males  and  females,  both  of  which  were  distinguished  by 
them  ;  and  in  their  progeny,  the  peculiarities  uniformly  appeared. 


TENDENCY   TO    SPONTANEOUS   VARIATION: — NEW   RACES.  833 

example,  the  members  of  a  six-fingered  family  were  to  intermarry  exclusively 
with  one  another, — any  such  variety  would  be  permanently  established  as  a  new 
race.  Now  if  it  be  borne  in  mind,  that  the  influence  of  a  scanty  population,  in 
the  early  ages  of  the  Human  race,  by  isolating  different  families  from  each  other, 
and  causing  intermarriages  among  even  the  nearest  relatives,  would  have  been 
precisely  the  same  with  that  which  is  now  exercised  by  the  breeders  of  animals, 
we  see  one  reason  why  the  varieties  which  then  arose  should  have  a  much  greater 
tendency  to  self-perpetuation,  than  those  which  now  occasionally  present  them- 
selves. And  when,  too,  it  is  borne  in  mind,  that  the  change  in  external  condi- 
tions induced  by  migration,  would  thus  operate  not  only  upon  the  parents  but 
upon  the  offspring,  and  would  have  a  continual  influence  in  so  modifying  the 
constitution  of  the  latter,  that  the  peculiarities  thus  acquired  by  them  would  be 
transmitted  in  yet  greater  intensity  to  their  progeny,  there  is  no  real  difficulty  in 
accounting,  upon  the  strictest  physiological  principles,  for  the  widest  departures 
from  one  common  type  of  conformation,  which  we  encounter  in  our  survey  of 
the  different  Races  of  Mankind.1 

946.  Hence  we  are  led  to  conclude,  that,  so  far  as  regards  their  Anatomical 
structure,  there  is  no  such  difference  among  them  as  would  justify  to  the  Zoolo- 
gist the  assertion  of  their  distinct  origin.     But  further,  although  the  comparison 
of  the  structural  characters  of  the  Human  races  does  not  furnish  any  positive 
evidence  of  their  descent  from  a  common  stock,  it  justifies  the  assertion  that 
even  if  their  stocks  were  originally  distinct,  there  could  have  been  no  essential 
difference  between  them ;  the  descendants  of  any  one  such  stock  being  able  to 
assume  the  characters  of  another.     This,  as  already  remarked,  can  be  proved  by 
historical  evidence  in  regard  to  a  sufficient  number  of  tribes,  to  justify  the  same 
assertion'with  respect  to  others,  whose  languages,  customs,  habits  of  thought,  &c. 
have  an  affinity  strong  enough  to  warrant  us  in  regarding  them  as  descendants 
of  the  same  stock,  whilst  their  physical  conformation  is  widely  different.     Each 
principal  geographical  area,  which  is  so  isolated  from  others  as  to  render  it  pro- 
bable, a  priori,  that  its  population  has  extended  from  one  centre, — such  as  the 
Continent  of  Africa,  or  America, — contains  races  of  very  diversified  physical 
characters,  whose  linguistic  affinities  make  it  almost  certain  that  they  must  have 
had  a  common  descent;  and  thus,  in  whatever  mode  the  types  of  the  principal 
varieties  are  selected,  they  are  found  to  be  connected  by  so  gradual  a  series  of 
intermediate  or  transitional  forms,  that  it  is  impossible  to  draw  any  such  line  of 
demarcation  between  them,  as  would  be  required  by  a  soundly-judging  Naturalist 
for  the  boundary  of  distinct  species. 

947.  A  very  important  confirmation  of  this  view,  is  afforded  by  the  essential 
agreement  which  exists  among  the  different  Races  of  Men   in  regard  to  their 
Physiological  history;  the  variations  which  they  present  not  being  greater  than 
those  which  we  meet-with  between   the  different  individuals  of  any  one   race. 
Thus,  we  not  only  find   the  average  duration  of  life  to  be  the  same  (making 
allowance  for  circumstances  which  are  likely  to  induce  disease)  but  the  various 
epochs  of  life, — such  as  the  times  of  the  first  and  second  dentition,  the  period 
of  puberty,  the  duration  of  pregnancy,  the  intervals  of  the  catamenia,  and  the 
time  of  their  final  cessation, — present  a  marked  general  uniformity,  such  as  does 
not  exist  among  similar  epochs  in  the  lives  of  species  that  are  nearly  allied  but 
yet  unquestionably  distinct.     Further,  the  different  races  of  Man  are  all  subject 
to  the  same  diseases,  both  sporadic,  endemic,  and  epidemic;  the  only  exceptions 
being  those,  in  which  the  constitution  of  a  race  has  grown  to  a  certain  set  of  in- 

1  For  a  masterly  digest  of  the  analogical  evidence  furnished  by  the  changes  known  to 
have  been  thus  produced  among  domesticated  animals,  and  of  the  modifications  which  par- 
ticular tribes  of  Men  can  be  shown  to  have  undergone  within  the  historic  period,  see  Dr. 
Prichard's  "  Physical  History  of  Mankind,"  and  his  "  Natural  History  of  Man,"  see,  also, 
the  summary  given  by  the  Author  in  the  "Cyclop,  of  Anat.  and  Physiol."  vol.  iv.,  pp. 
1301-1339. 
53 


834         OF    THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

fluences  (as  that  of  the  Negro  to  the  malaria  which  generate  certain  pernicious 
fevers  in  the  European),  producing  an  hereditary  immunity  in  the  race,  which  is 
capable  of  being  acquired  by  individuals  of  other  races,  by  a  process  of  acclima- 
tization commenced  sufficiently  early.1 — The  most  important  physiological  test, 
however,  of  specific  unity  or  diversity,  is  that  furnished  by  the  Generative  pro- 
cess. It  may  be  considered  as  a  fundamental  fact,  alike  in  the  Vegetable  and 
in  the  Animal  kingdom  (PaiNC.  OF  COMP.  PHYS.,  §  615,  Am.  Ed.),  that  hybrid 
races  originating  in  the  sexual  connection  of  individuals  of  two  different  species, 
do  not  tend  to  self-perpetuation ;  the  hybrids  being  nearly  sterile  with  each  other, 
although  they  may  propagate  with  either  of  their  parent-races,  in  which  the 
hybrid  race  will  soon  merge ;  whilst,  on  the  other  hand,  if  the  parents  be  them- 
selves varieties  of  the  same  species,  the  hybrid  constitutes  but  another  variety, 
and  its  powers  of  reproduction  are  rather  increased  than  diminished,  so  that  it 
may  continue  to  propagate  its  own  race,  or  may  be  used  for  the  production  of 
other  varieties,  almost  ad  infinitum.  It  appears  that,  among  Plants,  hybrids 
originating  between  undoubtedly  distinct  species,  sometimes  reproduce  themselves 
for  two  or  three  generations,  but  do  not  continue  beyond  the  fourth.  Amongst 
Animals,  the  limits  of  hybridity  between  parents  of  distinct  species  are  more 
narrow,  since  the  hybrid  is  totally  unable  to  continue  its  race  with  one  of  its  own 
kind ; 2  and  although  it  may  propagate  with  one  of  its  parent-species,  the  pro- 
geny will  of  course  approach  in  character  to  the  pure  breed,  and  the  race  will 
speedily  merge  into  it.  In  Animals,  as  among  Plants,  the  mixed  offsprings, 
originating  from  different  races  within  the  limits  of  the  same  species,  generally 
exceed  in  vigour,  and  in  the  tendency  to  multiply,  the  parent-races  from  which 
they  are  produced,  so  as  to  gain-ground  upon  the  older  varieties,  and  gradually 
to  supersede  them.  In  this  manner,  by  the  crossing  of  the  breeds  of  our  domes- 
ticated animals,  many  new  and  superior  varieties  have  been  produced.  The 
general  principle  is,  then,  that  beings  of  distinct  species,  or  descendants  from 
stocks  originally  different,  cannot  produce  a  mixed  race  which  shall  possess  the 
capability  of  perpetuating  itself;  whilst  the  union  of  varieties  has  a  tendency  to 
produce  a  race  superior  in  energy  and  fertility  to  its  parents. — The  application 
of  this  principle  to  the  Human  races,  leaves  no  doubt  with  respect  to  their  spe- 
cific unity;  for,  as  is  well  known,  not  only  do  all  the  races  of  Men  breed  freely 
with  each  other;  but  the  mixed  race  is  generally  superior  in  physical  develop- 
ment, and  in  tendency  to  rapid  multiplication,  to  either  of  the  parent-stocks;  so 
that  there  is  much  reason  to  believe  that,  in  many  countries,  the  mixed  race  be- 
tween the  Aborigines  and  European  colonizers  will  ultimately  become  the  domi- 
nant power  in  the  community.  This  is  especially  the  case  in  India,  South 
America,  and  Polynesia. 

1  This  view  of  the  immunity  of  the  Negro  race  from  certain  forms  of  Fever  which  are 
very  fatal  to  Europeans,  is  justified,  the  Author  believes,  by  all  the  facts  known  upon  the 
subject.  Much  may  be  set  down,  as  he  is  assured  by  Dr.  Daniell,  to  the  better  adapta- 
tion of  the  Negro  habits  of  life  to  their  climate ;  and  Europeans  who  exercise  due  caution 
(especially  in  regard  to  the  functions  of  the  skin),  may  preserve  an  immunity  scarcely 
less  complete.  Dr.  D.  himself,  having  been  taken  prisoner  by  one  of  the  Negro  tribes 
at  an  early  age,  and  having  spent  two  years  among  them,  seems  to  have  been  thoroughly 
acclimatized :  and  has  subsequently  passed  many  years  on  the  most  unhealthy  parts  of 
the  coast,  -without  experiencing  any  severe  attacks  of  illness,  and  in  the  enjoyment  of 
very  good  general  health. — It  is  sometimes  maintained  that  the  Negro  race  possesses 
such  a  complete  exemption  from  the  Yellow  Fever  of  the  United  States,  as  marks  its 
specific  difference ;  such,  however,  is  not  constantly  the  case,  since  Negroes  occasionally 
Buffer  from  it ;  and  their  comparative  immunity  seems  fairly  attributable  to  the  constitu- 
tional peculiarity  acquired  by  their  African  progenitors,  and  capable  of  being  acquired  by 
Europeans  also. 

a  One  or  two  instances  have  been  stated  to  occur,  in  which  a  Mule  has  produced  off- 
spring from  union  with  a  similar  animal ;  but  this  is  certainly  the  extreme  limit,  since  no 
one  has  ever  maintained  that  the  race  can  be  continued  further  than  the  second  genera- 
tion, without  admixture  with  one  of  the  parent-species. 


DIFFERENCE    AMONG    RACES    OF    MANKIND.  835 

948.  The  question  of  Psychical  conformity  or  difference  among  the  Races  of 
Mankind,  is  one  which  has  a  most  direct  bearing  upon  the  question  of  their 
specific  unity  or  diversity ;  but  it  has  an  importance  of  its  own,  even  greater  than 
that  which  it  derives  from  this  source.  For,  as  has  been  recently  argued  with 
great  justice  and  power,1  the  real  Unity  of  Mankind  does  not  lie  in  the  consan- 
guinity of  a  common  descent,  but  has  its  basis  in  the  participation  of  every  race 
in  the  same  moral  nature,  and  in  the  community  of  moral  rights  which  hence 
becomes  the  privilege  of  all.  "  This  is  a  bond  which  every  man  feels  more  and 
more,  the  farther  he  advances  in  his  intellectual  and  moral  culture,  and  which  in 
this  development  is  continually  placed  upon  higher  and  higher  ground ;  so  much 
so,  that  the  psychical  relation  arising  from  a  common  descent  is  finally  lost-sight-of, 
in  the  consciousness  of  the  higher  moral  obligations."  It  is  in  these  obligations, 
that  the  moral  rights  of  men  have  their  foundation ;  and  thus,  "  while  Africans 
have  the  hearts  and  consciences  of  human  beings,  it  could  never  be  right  to  treat 
them  as  domestic  cattle  or  as  wild  fowl,  if  it  were  ever  so  abundantly  demonstrated 
that  their  race  was  but  an  improved  species  of  ape,  and  ours  a  degenerate  kind  of 
god." — The  Psychical  comparison  of  the  various  Races  of  Mankind,  is  really, 
therefore,  in  a  practical  point  of  view,  the  most  important  part  of  the  whole  inves- 
tigation ;  but  it  has  been,  nevertheless,  the  one  most  imperfectly  pursued,  until 
the  inquiry  was  taken-up  by  l)r.  Prichard.  The  mass  of  evidence  which  he  has 
accumulated  on  this  subject,  however,  leaves  no  reasonable  doubt,  that  no  more 
"  impassable  barrier  "  really  exists  between  the  different  races  with  respect  to  this, 
than  in  regard  to  any  of  those  points  of  ostensible  diversity  which  have  been 
already  considered ;  the  variations  in  the  positive  and  relative  development  of 
their  respective  psychical  powers  and  tendencies,  not  being  greater,  either  in  kind 
or  degree,  than  those  which  present  themselves  between  individuals  of  our  own 
or  of  any  other  race,  by  some  members  of  which  a  high  intellectual  and  moral 
standard  has  been  attained.  The  tests  by  which  we  recognise  the  claims  of  the 
outcast  and  degraded  of  our  own  or  of  any  other  '  highly-civilized'  community,  to 
a  common  humanity,  are  the  same  as  those  by  which  we  should  estimate  the  true 
relation  of  the  Negro,  the  Bushman,  or  the  Australian,  to  the  cultivated  Euro- 
pean. If,  on  the  one  hand,  we  admit  the  influence  of  want,  ignorance,  and  ne- 
glect, in  accounting  for  the  debasement  of  the  savages  of  our  own  great  cities, — 
and  if  we  witness  the  same  effects  occurring  under  the  same  conditions  among 
the  Bushmen  of  Southern  Africa  (§  958), — we  can  scarcely  hesitate  in  admitting, 
that  the  long-continued  operation  of  the  same  agencies  has  had  much  to  do  with 
the  psychical  as  well  as  the  physical  deterioration  of  the  Negro,  Australian,  and 
other  degraded  races.  So,  on  the  other  hand,  if  we  cherish  the  hope  that  the 
former,  so  far  from  being  irreclaimable,  may  at  least  be  brought-up  to  the  standard 
from  which  they  have  degenerated,  by  means  adapted  to  develope  their  intellec- 
tual faculties  and  to  call-forth  the  higher  parts  of  their  moral  nature,  no  adequate 
reason  can  be  assigned  why  the  same  method  should  not  succeed  with  the  latter, 
if  employed  with  sufficient  perseverance.  It  will  be  only  when  the  effect  of  edu- 
cation, intellectual,  moral,  and  religious,  shall  have  been  fairly  tested  by  the  expe- 
rience of  many  generations,  in  conjunction  with  the  influence  of  a  perfect  equality 
in  civilization  and  social  position,  that  we  shall  be  entitled  to  speak  of  any  essen- 
tial and  constant  psychical  difference  between  ourselves  and  the  most  degraded 
beings  clothed  in  human  form.  All  the  evidence  which  we  at  present  possess, 
leads  to  the  belief,  that  under  a  vast  diversity  in  degree  and  in  modes  of  manifes- 
tation, the  same  intellectual,  moral,  and  religious  capabilities  exist,  in  all  the  Races 
of  Mankind ;  so  that,  whilst  we  may  derive  from  this  conformity  a  powerful  argu- 
ment for  their  zoological  Unity  as  a  species,  we  are  also  directly  led  to  recognize 
their  community  of  moral  nature  with  ourselves,  and  to  admit  them  to  a  participa- 
tion in  our  own  rights. 

1  See  the  "New  Quarterly  Review."  No.  xv.  p.131 ;  and  an  Article  by  Prof.  Agassiz  ia 
the  "Christian  Examiner,"  Boston  (N.  E.),  1850. 


836         OF    THE    BRANCHES     OF    THE     HUMAN    FAMILY. 

949.  Most  important  assistance  is  afforded  in  the  determination   of  the  real 
affinities  of  different  Races,  by  the  study  of  their  Languages.     This,  however,  is 
a  department  of  the  inquiry  so  far  beyond  the  limits  of  Physiological  science,  that 
it  must  be  here  dismissed  with  a  bare  mention  of  those  results,  to  which  the  zeal- 
ous pursuit  of  it  by  a  large  number  of  philosophic  Philologists  seems,  undoubtedly 
to  tend. — There  can  be  no  reasonable  doubt  that,  as  a  general  principle,  the  affi- 
nities of  races  are  more  surely  indicated  by  their  languages,  than  by  their  physical 
features;  and  the  experienced  philologist  is  generally  able  to  discriminate  those 
resemblances,  which  may  have  arisen  out  of  the  introduction  of  words  or  of  modes  of 
construction  from  the  one  into  the  other,  by  conquest,  commercial  intercourse,  or 
absolute  intermixture,  from  those  which  are  the  result  of  a  community  of  origin. 
And  thus  are  supplied  those  means  of  tracing  the  past  history  of  races,  which  are 
seldom  afforded  by  written  records,  or  even  (at  least  with  any  degree  of  certainty) 
by  traditional  information.     It  is  to  be  borne  in  mind,  that  the  affinities  of  lan- 
guages are  indicated,  not  merely  by  verbal  resemblance,  but  by  the  similarity  of 
their  modes  of  grammatical  construction,  or  the  methods  by  which  the  relation 
between  different  words  that  constitute  sentences,  is  indicated.     The  most  posi- 
tive evidence  is  of  course  afforded,  when  a  conformity  exists  both  in  the  vocabu- 
laries and  in  the  modes  of  construction  of  two  languages ;    but  it  frequently 
happens  that  although  the  conformity  exists  in  regard  to  one  of  these  alone,  yet 
the  evidence  which  it  affords  is  perfectly  satisfactory.     Thus,  there  are  many 
cases  in  which  the  vocabularies  are  so  continually  undergoing  important  changes 
(the  want  of  written  records  not  permitting  them  to  acquire  more  than  a  traditional 
permanence),  that  their  divergence  becomes  so  great,  even  in  the  course  of  a  few 
generations,  as  to  prevent  tribes  which  are  by  no  means  remotely  descended  from 
a  common  ancestry,  from  understanding  one  another;  whilst  yet  the  system  of 
grammatical  construction,  which  depends  more  upon  the  grade  of  mental  develop- 
ment and  upon  habits  of  thought,  exhibits  a  remarkable  permanence.      Such 
appears  to  be  true  of  the  entire  group  of  American  languages,  which  seem,  as  a 
whole,  to  be  legitimately  referable  to  a  common  stock,  notwithstanding  their  com- 
plete verbal  diversity.     On  the  other  hand,  when  two  languages  or  groups  of  lan- 
guages differ  greatly  in  construction,  but  present  that  kind  of  verbal  correspond- 
ence on  which  the  philologist  feels  justified  in  placing  most  reliance  (namely,  an 
essential  conformity  in  those  '  primary  words '  which  serve  to  represent  the  uni- 
versal ideas  of  a  people  in  the  most  simple  state  of  existence),  that  correspondence 
may  be  held  to  indicate  a  community  of  origin,  if  it  can  be  proved  that  it  has  not 
been  the  result  of  intercourse  between  the  two  families  of  nations  subsequently  to 
their  first  divergence,  and  if  it  seems  probable  on  other  grounds  that  their  separa- 
tion took  place  at  a  period  when  as  yet  the  grammatical  development  of  both  lan- 
guages was  in  its  infancy.     Such  appears  to  have  been  the  case  with  certain  of 
those  groups  of  languages,  whose  distinctness  can  be  traced  back  historically  for 
the  longest  period. — It  is  evident,  then,  that  Philological  inquiry  must  be  looked- 
to  as  one  of  the  chief  means  of  determining  the  question  of  radiation  from  a  single 
centre  or  from  multiple  centres ;  and  it  is  a  remarkable  fact,  that  the  linguistic 
affinity  and  the  conformity  in  physical  characters  frequently  stand  in  a  sort  of 
complemental  relation  to  each  other,  each  being  the  strongest  where  the  other  is 
weakest;  so  that,  by  one  or  other  of  these  links  of  connection,  a  close  relationship 
is  indicated  between  all  those  families  of  nations  under  which  the  several  races 
appear  to  be  most  naturally  grouped. 

2. —  General  Survey  of  the  Principal  Varieties  of  the  Human  Species. 

950.  The  distribution  of  the  Races  of  Mankind  under  five  primary  varieties, 
according  to  their  respective  types  of  cranial  conformation,  as  first  proposed  by 
Blumenbach,  is  still  so  commonly  received,  notwithstanding  the  distinct  proof 
which  has  been  given  of  the  fallacious  nature  of  its  basis,  that  it  will  be  desirable 


INDO-EUEOPEAN    NATIONS.  837 

to  explain  his  terms,  and  at  the  same  time  to  show  how  far  the  information  sub- 
sequently acquired  has  tended  to  modify  his  arrangement. — The  first  of  these 
varieties,  which  is  considered  to  be  distinguished  by  the  possession  of  the  oval  or 
elliptical  type  of  cranial  conformation,  was  designated  Caucasian  by  Blumenbach, 
on  two  grounds ;  first,  because  he  considered  the  Caucasian  people  (of  whom  the 
Georgians  and  Circassians  are  the  best-known  examples),  as  presenting  its  physi- 
cal characters  in  the  greatest  perfection;  and  second,  because  it  was  supposed 
that  the  Caucasian  range  of  mountains  might  be  regarded  as  the  centre  or  focus 
of  the  races  belonging  to  it.  Neither  of  these  ideas,  however,  is  correct :  for 
whilst  the  oval  form  of  cranium  is  presented  with  fully  as  great  beauty  and  sym- 
metry by  the  Greeks,  it  seems  now  to  be  almost  certainly  determinable  by  the 
evidence  of  language,  that  the  Georgian  and  Circassian  nations  are  really  of  Mon- 
golian origin,  and  consequently  have  no  direct  relation  of  affinity  with  the  other 
nations  usually  ranked  as  belonging  to  this  variety  j  and  the  evidence  of  history 
and  tradition,  so  far  from  pointing  to  the  Caucasian  range  as  the  original  centre 
of  radiation  of  the  race,  accords  with  that  of  language  in  assigning  its  locality 
much  nearer  to  Central  Asia.  It  would  be  most  desirable,  therefore,  that  some 
other  designation  should  be  substituted  for  that  given  by  Blumenbach  ;  were  it 
not  that  the  present  state  of  our  knowledge  requires  the  entire  abandonment  of 
his  doctrine  that  the  races  agreeing  in  this  type  of  conformation  are  mutually 
connected  by  community  of  descent.  For,  even  within  the  limits  of  Europe,  we 
find  at  least  two  nations, — the  Turks,  and  the  Magyars  or  true  Hungarians, — 
whose  crania  are  characteristically  oval,  and  which  are  yet  undoubtedly  of  Mon- 
golian origin ;  and  although  some  allowance  must  be  made,  in  regard  to  the 
change  which  has  taken  place  among  the  former,  for  the  influence  of  intermix- 
ture with  other  races,  yet  there  is  no  reason  to  believe  that  any  such  influence  has 
operated  among  the  Magyars,  whose  blood  seems  to  have  been  transmitted  with 
remarkable  purity  from  the  time  when  they  settled  in  Hungary  about  ten  cen- 
turies since.  In  Asia,  we  find  this  type  presented  not  merely  by  the  Persian  and 
other  Indo-European  races,  but  also  by  the  Syro-Arabian,  and  by  the  larger  pro- 
portion of  the  inhabitants  of  Hindostan ;  yet  the  Syro-Arabian  races  are  more 
nearly  related  to  the  African  stock  (§  952),  than  to  that  from  which  most  of  the 
present  inhabitants  of  Europe  have  sprung;  and  there  is  good  reason  to  believe 
that  the  great  mass  of  the  existing  inhabitants  of  India,  are  of  Mongolian  descent 
(§  954).  It  will  be  necessary,  therefore,  to  consider  the  nations  which  present 
the  so-called  Caucasian  type  of  cranial  conformation,  under  several  distinct 
heads.  No  uniformity  exists  among  them  in  regard  to  colour  ;  for  this  character 
presents  every  intermediate  gradation  between  the  fair  and  florid  tint,  with 
light-red  or  auburn  hair,  of  the  Northern  European,  to  the  dusky  or  even  black 
hue  of  the  races  bordering-on  or  lying-between  the  Tropics.  The  hair  is  gene- 
rally long  and  flexible,  with  a  tendency  to  curl ;  but  considerable  variety  presents 
itself  with  regard  to  this  particular.  The  conformation  of  the  features  approaches 
more  or  less  closely  to  that  which  we  are  accustomed  to  regard  as  the  type  of 
beauty. 

951.  The  first  place,  in  a  more  natural  distribution  of  the  Human  Races,  must 
undoubtedly  be  given  to  that  which  is  designated  by  Dr.  Prichard  as  the  Arian, 
and  which  is  ofren  termed  the  Indo-European;  including  the  collective  body  of 
European  nations,  with  the  Persians,1  Aflghans,  and  certain  other  nations  of  the 

1  The  modern  Persians  are  a  very  mixed  race,  in  which  Turkish  and  Arab  elements 
largely  participate.  The  most  perfect  representatives  of  the  original  stock  (whose  purity 
of  descent  seems  to  have  been,  maintained,  from  the  time  of  their  original  migration  into 
their  present  locality,  by  the  physical  obstacles  which  have  cut  them  off  from  intercourse 
•with  their  nearest  neighbours)  are  believed  to  be  the  Kafirs  of  Kafiristan,  a  fair-skinned 
light-haired  race  inhabiting  the  impracticable  mountain-country  on  thfc  watershed  between 
the  Oxus  and  the  north-western  sources  of  the  Indus.  The  Tajiks  of  Bokhara  also  keep- 
up  the  ancient  lineage  and  language,  although  their  country  is  ruled  by  people  of  Turkish 
descent. 


838         OF    THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

south-western  portion  of  the  Asiatic  continent,1  near  to  which  their  original  focus 
appears  to  have  been.     The  great  bond  of  connection  between  these  nations,  lies 
in  their  languages  ;   which,  in  spite  of  great  diversities,  present  a  certain  com- 
munity of  character  that  is  recognized  by  every  philologist.     For  they  are  obvi- 
ously all  formed  upon  the  same  base  with  the  ancient  Sanskrit,  if  not  upon  the 
Sanskrit  itself;  and   they  are  united  alike  by  community  in  many  of  the  most 
important  '  primary  words/  and  by  general  similarity  in  grammatical  construction. 
The  existing  Lettish  or  Lithuanian  dialect  presents  a  very  near  approach  to  the 
original  type ;  and  the  Old  Prussian,  a  dialect  spoken  as  late  as  the  sixteenth  cen- 
tury, had  a  still  closer  alliance  to  the  ancient  Zend  or  Median,  which  seems  to 
have  been  a  very  early  derivation  from  the  Sanskrit,  and  which  is  the  basis  of 
the  language  now  spoken  in  Persia.     The  family  which  is  most  dissimilar  to  the 
rest  (the   typical  Celt  contrasting  remarkably  with    the  types  of  the   Germanic 
group,  both  in  physical  conformation  and  in  psychical  characters,)  is  that  which 
is  formed  by  the  Celtic  nations;  but  these  are  undoubtedly,  like  the  others,  of 
Eastern  origin,  as  was  first  shown  by  Dr.  Prichard  ;2  though  they  appear  to  have 
detached  themselves  from  the  common  stock  at  an  earlier  period  in  the  develop- 
ment of  its  language. — But  there  is  evidence  that,  notwithstanding  the  mutual 
affinities  of  the  Indo-Germanic  languages,  every  one  of  them  has  been  modified 
by  the  introduction  of  extraneous  elements :  thus,  in  those  of  Western  Europe, 
there  is  a  considerable  admixture  of  Celtic ;  whilst  in  others,  there  are  traces  of 
more  barbaric  tongues.     In  fact,  there  can   be  little  doubt  that  Europe  had  an 
indigenous  population,  before  the  immigration  of  the  Indo-German  or  even  of  the 
Celtic  tribes;  and  of  this  population  it  seems  most  probable  that  the  Lapps  and 
Finns  of  Scandinavia,  and  the  Euskarians  (or  Basques)  of  the  Biscayan  provinces, 
are  but  the  remnant.     The  former  of  these  tribes,  which  is  undoubtedly  of  Mon- 
golian origin,  once  extended  much  further  south  than  at  present;  and  with  regard 
to  the  latter,  whose  nearest  linguistic  affinities  are  also  with  the  tongues  of  High 
Asia,  there  is  ample  historical  proof  that  they  had  formerly  a  very  extensive  dis- 
tribution through  Southern  Europe.     It  would  not  seem  improbable,  then,  that 
the  advance  of  the  Indo-European  tribes  from  the  south-east  corner  into  central 
Europe,  separated   that  portion  of  the  aboriginal  (Mongolian)  population  which 
they  did  not  absorb  or  destroy,  into  two  great  divisions ;  of  which  one  was  gradu- 
ally pressed  northward  and  eastward,  so  as  to  be  restricted  to  Finland  and  Lap- 
land; and  the  other  southward  and  westward,  so  as  to  be  confined  at  the  earliest 
historic  period  to  a  part  of  the  peninsula  of  Spain  and  the  South  of  France,  gra- 
dually to  be  driven  before  the  successive  irruptions  of  the  Celts,  Romans,  Ara- 
bians, and  other  nations,  until  their  scanty  remnant  found  an  enduring  refuge  in 
the  fastnesses  of  the  Pyrenees.3 — The  Indo-Germanic  race  is  unquestionably  that 
which  has  exercised  the  greatest  influence  on  the  civilization  of  the  Old  World ; 
and  it  seems  indubitably  destined  to  acquire  a  similar  influence  in  those  newly- 
found  lands  which  have  been  discovered  by  its  enterprise.     With  scarcely  an  ex- 
ception, as  Dr.  Latham  has  justly  remarked,  the  nations  belonging  to  it  present 
an  encroaching  frontier :  there  being  no  instance  of  its  permanent  displacement 
by  any  other  race,  save  in  the  case  of  the  Arab   dominion   in  Spain,  which  has 
long  since  ceased;  in  that  of  the  Turkish  dominion  in  Turkey  and  Asia  Minor, 
which  is  evidently  destined  to  expire  at  no  distant  period,  being  upheld  for  merely 
political  purposes  by  extraneous  influence ;  and  in  that  of  the  Magyars  in  Hun- 

1  The  population  of  Hindostan  has  been  commonly  accounted  as  belonging  to  this  divi- 
sion ;  but  the  more  intimate  the  knowledge  attained  of  its  character  and  languages,  the 
more  does  it  lead  to  the  conclusion  that  the  great  mass  of  this  population  is  really  of  Mon 
golian  descent  ($  954). 

8  "  On  the  Eastern  Origin  of  the  Celtic  Nations,"  1831. 

3  This  view,  which  was  suggested  by  the  Author  in  the  "Brit,  and  For.  Med.  Rev.,"0ct' 
1847,  without  the  knowledge  that  it  had  been  elsewhere  propounded,  has  been  put-forth 
with  considerable  confidence  by  Dr.  Latham  ("Varieties  of  Man,"  1850),  as  having  origi- 
nated with  Arndt  and  been  adopted  by  Rask,  distinguished  Scandinavian  ethnologists 


SYRO-ARABIAN    NATIONS.  839 

gary,  who  only  maintain  their  ground  through  their  complete  assimilation  to  tho 
Indo-Germanic  character.  It  is  a  remarkable  fact,  that  in  most  cases  in  which 
this  race  extends  itself  into  countries  previously  tenanted  by  people  of  an  entirely 
different  type,  the  latter  progressively  decline  and  at  last  disappear  before  it,  pro- 
vided the  climate  be  such  as  enables  it  to  maintain  a  vigorous  existence;  this  is 
pre-eminently  the  case  in  North  and  South  America,  in  Australia,  in  New  Zea- 
land, and  in  many  of  the  smaller  Polynesian  islands.  And  where  the  climate  is 
less  favourable  to  the  perpetuation  of  the  race  in  its  purity,  an  intermixture  with 
the  native  blood  frequently  gives  origin  to  a  mixed  race,  which  possesses  the  de- 
veloped intellect  of  the  one,  and  the  climatic  adaptiveness  of  the  other,  and  which 
appears  likely  ultimately  to  take  the  place  of  both. 

952.  The  Syro-Arabian  or  Semitic  nations  agree  with  the  preceding  in  gene- 
ral physical  characters,  but  differ  entirely  in  the  structure  of  their  language,  and 
for  the  most  part  in  vocabulary  also,  though  recent  researches  seem  to  indicate 
that  certain  roots  of  the  Semitic  and  Indo-Germanic  languages  have  a  decided 
affinity.  It  seems  quite  certain,  however,  that  the  linguistic  affinities  of  the  Se- 
mitic nations  are  rather  with  the  African  than  with  the  Indo-European  races ; 
and  so  strong  is  the  link  of  connection  thus  established,  that  by  Dr.  Latham  they 
are  ranked  with  the  former  under  the  general  designation  Atlantidce,1  whilst  Mr. 
Norris,  whose  authority  upon  all  such  subjects  is  deservedly  great,  is  strongly 
disposed  (as  he  has  himself  informed  the  Author)  to  consider  them  an  essentially 
African  people. — The  original  seat  of  this  race,  however,  is  commonly  reputed  to 
have  been  that  region  of  Asia  which  is  intermediate  between  the  countries  of  the 
Indo-European  and  of  the  Egyptian  races;  having  as  its  centre  the  region  watered 
by  the  great  rivers  of  Mesopotamia.  Several  of  the  nations  primarily  constituting 
this  group  have  become  extinct,  or  nearly  so;  and  the  Arabs,  which  originally 
formed  but  one  subdivision  of  it,  have  now  become  the  dominant  race,  not  only 
throughout  the  ancient  domain  of  the  Syro-Arabian  nations,  but  also  in  Northern 
Africa.  In  the  opinion  of  Baron  Larrey,  who  had  ample  opportunities  for  obser- 
vation, the  skulls  of  the  Arabian  race  furnish,  at  present,  the  most  complete  type 
of  the  human  head ;  and  he  considered  the  remainder  of  the  physical  frame  as 
equally  distinguished  by  its  superiority  to  that  of  other  races  of  men.  The  differ- 
ent tribes  of  Arabs  present  very  great  diversities  of  colour,  which  are  generally 
found  to  coincide  with  variations  in  climate.  Thus  the  Shegya  Arabs,  and  others 
living  on  the  low  countries  bordering  on  the  Nile,  are  of  a  dark-brown  or  even 
black  hue ;  but  even  when  quite  jetty,  they  are  distinguished  from  the  Negro  races 
by  the  brightness  of  their  complexions,  by  the  length  and  straightness  of  their 
hair,  and  by  the  regularity  of  their  features.  The  same  may  be  said  of  the  wan- 
dering Arabs  of  Northern  Africa;  but  the  influence  of  climate  and  circumstances 
is  still  more  strongly  marked  in  some  of  the  tribes  long  settled  in  that  region, 
whose  descent  may  be  traced  to  a  distinct  branch  of  the  Syro-Arabian  stock, 
namely,  the  Berber,  to  which  belong  the  Kabyles  of  Algiers  and  Tunis,  the  Tua- 
vyks  of  Sahara,  and  the  Guanches  or  ancient  population  of  the  Canary  Isles. 
Amongst  these  tribes,  whose  affinity  is  indisputably  traceable  through  their  very 
remarkable  language,  every  gradation  may  be  seen,  from  the  intense  blackness  of 
the  Negro  skin,  to  the  more  swarthy  hue  of  the  inhabitants  of  the  South  of  Eu- 
rope. It  is  remarkable  that  some  of  the  Tuaryk  inhabitants  of  particular  Oases 
in  the  great  desert,  who  are  almost  as  insulated  from  communication  with  other 
races  as  are  the  inhabitants  of  islands  in  a  wide  ocean,  have  hair  and  features 
that  approach  those  of  the  Negroes ;  although  they  speak  the  Berber  language 
with  such  purity,  as  to  forbid  the  idea  of  the  introduction  of  these  characters  by 
un  intermixture  of  races.  The  Jews,  who  are  the  only  remnants  now  existing  or 
the  once-powerful  Phoenician  tribe,  and  who  are  now  dispersed  through  nearly 
every  country  on  the  face  of  the  earth,  present  a  similar  diversity;  having  gradu- 

1  See  his  "Varieties  of  Man,"  1850,  p.  469. 


840         OP    THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

ally  assimilated  in  physical  characters  to  the  nations  among  which  they  have  so 
long  resided  (§  934). 

953.  The  second  primary  division  of  the  Human  family,  according  to  the  ar- 
rangement of  Blumeubach,  is  that  commonly  termed  Mongolian.     The  real  Mon- 
gols, however,  constitute  but  a  single  and  not  very  considerable  member  of  the 
group  of  nations  associated   under  this  designation;  which  is,  therefore,  by  no 
means  an  appropriate  one.     The  original  seat  of  these  races  appears  to  have  been 
the  great  central  elevated  plain  of  Asia,  in  which  all  the  great  rivers  of  that  con- 
tinent have  their  sources,,  whatever  may  be  their  subsequent  direction.     Taken 
as  a  whole,  this  division   is  characterized  by  the   pyramidal  form  of  the  skull, 
whose  antero-posterior  diameter  scarcely  exceeds  the  parietal,  and  by  the  broad 
flat  face  and  prominent  cheek-bones;  by  the  flattening  of  the  nose,  which  is  nei- 
ther arched  nor  aquiline ;  by  the  eyes  being  drawn  upwards  at  their  outer  angle  ; 
by  the  xanthous  or  olive   complexion,  which   sometimes  becomes  fair,  but  fre- 
quently swarthy;  by  the  scantiness  and  straightness  of  the  hair,  and  deficiency  of 
beard ;  and  by  lowness  of  stature.     These  characters,  however,  are  exhibited  in  a 
prominent  degree  only  in  the  more  typical  members  of  the  group,  especially  those 
inhabiting  Northern  and  Central  Asia;  and  may  become  so  greatly  modified,  as 
to  cease  altogether  to  be  recognizable.     Such  a  modification  has  been  remarkably 
effected  in  the  case  of  a  part  of  the  Turkish  people,  now  so  extensively  distributed. 
All  the  most  learned  writers  on  Asiatic  history  are  agreed  in  opinion,  that  the 
Turkish  races  are  of  one  common  stock ;  although  at  present  they  vary  in  physi- 
cal characters,  to  such  a  degree  that,  in  some,  the  original  type  has  been  altoge- 
ther changed.     Those  which  still- inhabit  the  ancient  abodes  of  the  race,  and  pre- 
serve their  pastoral  nomadic  life,  present  the  physiognomy  and  general  character- 
istics which  appear  to  have  belonged  to  the  original  Turkomans ;  and  these  are 
decidedly  referable  to  the  so-called  Mongolian  type.     Before  the  Mahominedan 
era,  however,  the  Western  Turks  or  Osinanlis  had  adopted  more  settled  habits, 
and  had  made  considerable  progress  in  civilization;  and  their  adoption  of  the  reli- 
gion of  Islam  incited  them  to  still  wider  extension,  and  developed  that  spirit  of 
conquest,  which,  during  the  middle  ages,  displayed  itself  with  such  remarkable 
vigour.     The  branches  of  the  race,  which,  from  their  long  settlement  in  Europe, 
have  made  the  greatest  progress  in  civilization,  now  exhibit  in  all  essential  parti- 
culars the  physical  characters  of  the  European  model ;  and  these  are  particularly 
apparent  in  the  conformation  of  the  skull. — Another  marked  departure  from  the 
ordinary  Mongolian  type,  is  presented  by  the  Hyperborean  tribes  inhabiting  the 
borders  of  the  Icy  Sea;  these  have  for  the  most  part  a  pyramidal  skull,  but  their 
complexion  is  swarthy  and  their  growth  is  peculiarly  stunted ;  and  they  form  the 
link  that  connects  the  ordinary  Mongolidae  with  the  Lapps  and  Finns  of  Europe 
on   one  side,  and  with  the  Esquimaux  of  North  America  on  the   other.     The 
Ugrian  division,  which  migrated  towards  the  north-west  at  a  very  early  period, 
planted  a  colony  in   Europe,  which  still  tenants  the   northern  Baltic  countries, 
forming  the  races  of  Finns  and  Lapps.     In  the  time  of  Tacitus,  the  Finns  were 
as  savage  as  the  Lapps;  but  the  former,  during  the  succeeding  ages,  became  so 
far  civilized,  as  to  exchange  a  nomadic  life  for  one  of  agricultural  pursuits,  and 
have  gradually  assimilated  with  the  surrounding  people ;  whilst  the  Lapps,  like 
the  Siberian  tribes  of  the  same  race,  have  ever  since  continued  to  be  barbarous 
nomades,  and  have  undergone  no  elevation  in  physical  characters.     The  same  di- 
vision gave  origin  to  the  Magyars  or  Hungarians;  a  warlike  and  energetic  people, 
unlike  their  kindred  in  the  North ;  in  whom  a  long  abode  in  the  centre  of  Europe 
has,  in  like  manner,  developed  the  more  elevated  characters,  physical  and  mental, 
of  the  European  nations. 

954.  The  nations  inhabiting  the  South-eastern  and  Southern  portions  of  Asia, 
also,  appear  to  have  had  their  origin  in  the  Mongolian  or  Central- Asiatic  stock ; 
although  their  features  and  form  of  skull  by  no  means  exhibit  its  characteristic 
marks,  but  present  such  departures  from  it,  as  are  elsewhere  observable  in  races 


MODIFICATIONS    OF    MONGOLIAN    TYPE.  8'U 

that  are  making  advances  in  civilization.     The  conformity  to  the  Mongolian  type 
is  most  decidedly  shown  by  the   nations  (collectively  termed    Striform  by  Dr. 
Latham),  which  inhabit  China,  Thibet,  the  Indo-Chinese  peninsula,  and  the  base 
of  the  Himalayan  range  ;  these  are  associated  by  certain  linguistic  peculiarities 
which  distinguish  them  from  all  other  races ;  that  primitive  condition  of  human 
speech,  in  which  there  is  a  total  absence  of  inflections  indicative  of  the  relation 
of  the  principal  words  to  one   another;  being  apparently  preserved  with   less 
change  in  the  tongues  of  these  people,  than  in  those  of  any  other.     The  Chinese 
may  be  physically  characterized  as  Mongolians  softened-down ;  and  in  passing 
from  China  towards  India,  through  the  Burmese   empire,  there  is  so  gradual  a 
transition  towards  the  ordinary  Hindoo  type,  that  no  definite  line  of  demarcation 
can  be  anywhere  drawn.  — The  inhabitants  of  the  great  peninsula  of  Hindostan 
have  been  commonly  ranked  (as  already  remarked)  under  the  Caucasian  race; 
both  on  account  of  their  physical  conformity  to  that  type,  and  also  because  it  has 
been  considered  that  the  basis  of  their  languages  is  Sanskritic.     It  is  certain, 
however,  that  this  conclusion  is  incorrect  with  regard  to  a  very  large  proportion 
of  the  existing  population  of  India;  and  there  is  strong  reason  to  believe  that  no 
part  of  it  bears  any  real  relation   of  affinity  to  the  Indo-European   group  of 
nations,  except  such  as  may  be  derived  from  a  slight  intermixture      Thus,  the 
TamuliaHj  which  is  the  dominant  language  of  Southern  India,  is  undoubtedly 
not  Sanskritic  in  its  origin  (although  containing  an  infusion  of  Sanskritic  words), 
but  more  closely  approximates  to  the  Seriform  type ;  and  many  of  the  hill-tribes, 
in  different  parts  of  India,  speak  peculiar  dialects,  which,  though  mutually  un- 
intelligible, appear  referable  to  the  same  stock.     Now  it  is  among  this  portion  of 
the  population  of  India,  that  the  greatest  departure  presents  itself  from  the  Cau- 
casian type  of  cranial  formation,  and  the  closest  conformity  to  the  Mongolian ; 
the  cheek-bones  being  more  prominent,  the  hair  coarse,  scanty,  and  straight,  and 
the  nose  flattened;  sometimes,  also,  the  lips  are  very  thick,  and  the  jaws  project, 
showing  an  approximation  to  the  prognathous  type.     Now  in  the  opinion  of  Dr. 
Latham  and  Mr.  Norris,  the  various  dialects  of  Northern  India  (of  which  the 
Hindustani  is  the  most  extensively  spoken)  are  to  be  regarded  as  belonging,  in 
virtue  of  their  fundamental  nature,  to  the  same  group  with  those  of  High  Asia, 
notwithstanding  the  large  infusion  of  Sanskritic  words  which  they  contain  ;  this 
infusion  having  been  introduced  at  an  early  period  by  an  invading  branch  of  the 
Arian  stock,  of  whose  advent  there  is  historical  evidence,  and  whose  descendants 
the  ordinary  Hindoo  population  have  been  erroneously  supposed  to  be.     Accord- 
ing to  this  view,  then,  the  influence  of  the  Arian  invasion  upon  the  language  and 
population  of  Northern  India,  was  very  much  akin  to  that  of  the  Norman  inva- 
sion upon  those  of  England ;    the  number  of  individuals  of  the  invading  race 
being  so  small  in  proportion  to  that  of  the  indigenous  population,  as  to  be  speedily 
merged  in  it,  not,  however,  without  contributing  to  an  elevation  of  its  physical 
characters ;  and  a  large  number  of  new  words  having  been  in  like  manner  intro- 
duced, without  any  essential  change  in  the  type  of  the  original  language.     And 
thus  the  only  distinct  traces  of  the  Arian  stock  are  to  be  found  in  the  Brahrni- 
nical  caste,  which  preserves  (though  with  great  corruption)  the  original  Brahmi- 
nical  religion,  and  which  keeps-up  the  Sanskrit  as  its  classical  language ;  it  is 
certain,  however,  that  this  race  is  far  from  being  of  pure  descent,  having  inter- 
mingled to  a  considerable  extent  with  the  ordinary  Hindoo  population.     There 
is  but  little  to  remind  us  of  the  Mongolian  type  in  the  countenances   of  the 
Hindoos,  which  are  often  remarkable  for  a  symmetrical  beauty  that  only  wants  a 
more  intellectual  expression  to  render  them  extremely  striking;  some  traces  of 
it,  however,  may  perhaps  be  found  in  the  rather  prominent  zygomatic  arches 
which  are  common  amongst  them;  but  the  cranial  portion  of  the  skull  presents 
no  approach  to  the  pyramidal  type,  being  often  very  regularly  elliptical.     There 
is  a  remarkable  difference  in   the  colour  of  the   different  Hindoo  tribes ;  SOUK? 
being  nearly  as  dark  as  Negroes,  others  more  of  a  copper  colour,  and  others  but 
little  darker  than  the  inhabitants  of  Southern  Europe. 


£42         OF     THE    BRANCHES    OF    THE    HUMAN    FAMILY. 

955.  According  to  the  usual  mode  of  dividing  the  Human  family,  the  Ethio- 
pian or  Negro  stock  is  made  to  include  all  the  nations  of  Africa,  to  the  south- 
ward of  the  Atlas  range.     But,  on  the  one  hand,  the  Hottentots  and  Bushmen 
of  the  southern  extremity  constitute  a  group  which  is  strongly  distinguished  by 
physical  characters  from  the  rest  of  the  African  nations;  so,  again,  the  region 
north  of  the  Great  Desert  is  mostly  occupied  by  Semitic  tribes  (§  952) ;  the  scat- 
tered population  of  the  Great  Desert  itself  is  far  from  being  Negro  in  many  of 
its  features  ;  the  valley  of  the  Nile,  at  least  in  its  middle  and  lower  portions,  in- 
cluding Egypt,  Nubia,  and  even   Abyssinia,  is  inhabited  by  a  group  of  nations 
which  may  be  designated  as  Nilotic,  and  which  presents  a  series  of  gradational 
transitions  between  the  Negroes  and  Kaffres  and  the  Semitic  races  ;  a  large  por- 
tion of  the  area  south  of  the  Equator  is  occupied  by  the  Kaffre  tribes  and  their 
allies,  which  cannot  be  truly  designated  as  Negroes :  so  that  the  true  Negro  area 
is  limited  to  the  western  portion  of  the  African  continent,  including  the  alluvial 
valleys  of  the  Senega],  the  Gambia,  and  the  Niger,  with  a  narrow  strip  of  cen- 
tral Africa,  passing  eastwards  to  the  alluvial  regions  of  the  Upper  Nile.     Even 
within  this  area,  the  true  Negro  type  of  conformation,  such  as  we  see  in  the  races 
which  inhabit  the  low  countries  near  the  Slave  Coast,  —  consisting  in  the  combi- 
nation of  the  prognathous  form  of  skull,  with  receding  forehead  and  depressed 
nose,  thick  lips,  black  woolly  hair,  jet-black  unctuous  skin,  and  crooked  legs, — 
is  by  no  means  universally  prevalent;  for  many  of  the  nations  which  inhabit  it, 
must  be  ranked  as  sub-typical  Negroes;  and  from  these  the  gradation  in  physical 
characters  is  by  no  means  abrupt,  to  those  African  nations  which  possess,  in  a 
considerable  degree,  the  attributes  which  we  are  accustomed  to  exclude  altogether 
from  our  idea  of  the  African  race.     Thus,  the  race  of  Jolofs  near  the  Senegal, 
and  the  Guber  in  the  interior  of  Sudan,  have  woolly  hair  and  deep-black  com- 
plexions, but  fine  forms  and  regular  features  of  a  European  cast;  and  nearly  the 
same  may  be   said  of  the   darkest  of  the   Kaffres   of  Southern   Africa.     The 
Bechuana  Kaffres  present  still  a  nearer  approach  to  the  European  type ;  the  com- 
plexion being  of  a  light-brown,  the  hair  often  not  woolly  but  merely  curled,  or 
even  in  long  flowing  ringlets,  and  the  figure  and  features  having  much  of  the 
European  character. — There  is  no  group,  in  fact,  which  presents  a  more  constant 
correspondence  between  external  conditions  and  physical  conformation,  than  that 
composed  of  the  African  nations.     As  we  find   the   complexion  becoming  gra- 
dually darker,  in  passing  from  Northern  to  Southern  Europe,  thence  to  North 
Africa,  thence  to  the  borders  of  the  Great  Desert,  and  thence  to  the  intertropical 
region  where  alone  the  dullest  black  is  to  be  met  with, — so  do  we  find,  on  passing 
southwards  from  this,  that  the  hue  becomes  gradually  lighter  in  proportion  as  we 
proceed  further  from  the  equator,  until  we  meet  with  races  of  comparatively  fair 
complexions  among  the  nations  of  Southern  Africa.     Even  in  the  intertropical 
region,  high  elevations  of  the  surface  have  the  same  effect  as  we  have  seen  them 
to  produce  elsewhere,  in  lightening  the  complexion.     Thus  the  high   parts  of 
Senegambia,  where  the  temperature  is  moderate  and  even  cool  at  times,  are  in- 
habited  by  Fulahs   of  a  light  copper  colour,  whilst  the   nations  inhabiting  the 
lower  regions  around  them  are  of  true  Negro  blackness;  and  nearly  on  the  same 
parallel,  but  at  the  opposite  side  of  Africa,  are  the  high  plains  of  Enarea  and 
Kaffa,  of  which  the  inhabitants  are  said  to  be  fairer  than  the  natives  of  Southern 
Europe. 

956.  The  languages  of  the  Negro  nations,  so  far  as  they  are  known,  appear  to 
belong  to  one  group ;  for  although  there  is  a  considerable  diversity  in  their  vo- 
cabularies (arising  in  great  part  from  the  want  of  written  records  which  would 
give  fixity  to  their  tongues),  yet  they  seem  to  present  the  same  grade  of  develop 
ment  and  the  same  grammatical  forms;  and  various  proofs  of  their  affinity  with 
the  Semitic  languages  have  been  developed,  these  being  afforded  by  similarity 
alike  of  roots  and  of  grammatical  construction.     The   Semitic   affinity  of  the 
Negro  nations  is  further  indicated  in  a  very  remarkable  manner,  by  the  existence 


AFRICAN    NATIONS.  843 

of  a  variety  of  superstitions  and  usages  among  the  Negroes  of  the  Western  coast, 
closely  resembling  those  which  prevail  also  among  the  Nilotic  races  whose  Semitic 
relations  are  most  clear,  as  well  as  among  branches  of  the  Semitic  stock  itself; 
and  thus  we  seem  to  have  adequate  proof  of  the  absence  of  any  definite  line  of 
demarcation,  in  regard  either  to  physiological  or  to  linguistic  characters,  between 
the  Negro  race,  and  one  of  those  which  has  been  hitherto  considered  to  rank 
among  the  most  elevated  forms  of  the  Caucasian  variety. — Nor  is  there  anything 
in  the  psychical  character  of  the  Negro,  which  gives  us  a  right  to  separate  him 
from  other  races  of  Mankind.  It  is  true  that  those  races  which  have  the  Negro 
character  in  an  exaggerated  degree,  are  uniformly  in  the  lowest  stage  of  society, 
being  either  ferocious  savages,  or  stupid,  sensual,  and  indolent  ;  such  are  most 
of  the  tribes  along  the  Slave  Coast.  But,  on  the  other  hand,  there  are  many 
Negro  States,  the  inhabitants  of  which  have  attained  a  considerable  degree  of 
improvement  in  their  social  condition  ;  such  are  the  Ashanti,  the  Sulima,  and  the 
Dahomans  of  Western  Africa,  also  the  Guber  of  Central  Sudan,  among  which  a 
considerable  degree  of  civilization  has  long  existed;  the  physical  characters  of 
all  these  nations  deviate  considerably  from  the  strongly-marked  or  exaggerated 
type  of  the  Negro ;  and  the  last  are  perhaps  the  finest  race  of  genuine  Negroes 
on  the  whole  continent,  and  present  in  their  language  the  most  distinct  traces  of 
original  relationship  to  the  Syro- Arabian  nations.  The  highest  civilization,  and 
the  greatest  improvement  in  physical  characters,  are  to  be  found  in  those  African 
nations  which  have  adopted  the  Mahommedan  religion;  this  was  introduced, 
three  or  four  centuries  since,  into  the  eastern  portion  of  Central  Africa;  and  it 
appears  that  the  same  people,  which  were  then  existing  in  the  savage  condition 
still  exhibited  by  the  pagan  nations  further  south,  have  now  adopted  many  of  the 
arts  and  institutions  of  civilized  society,  subjecting  themselves  to  governments, 
practising  agriculture,  and  dwelling  in  towns  of  considerable  extent,  many  of 
which  contain  10,000,  and  some  even  30,000  inhabitants;  a  circumstance  which 
implies  a  considerable  advancement  in  industry,  and  in  the  resources  of  subsist- 
ence. This  last  fact  affords  most  striking  evidence  of  the  improvability  of  the 
Negro  races ;  and,  taken  in  connection  with  the  many  instances  that  have  pre- 
sented themselves,  of  the  advance  of  individuals,  under  favourable  circumstances, 
to  at  least  the  average  degree  of  mental  development  among  the  European  nations, 
it  affords  clear  proof  that  the  line  of  demarcation,  which  has  been  supposed  to 
separate  them  intellectually  and  morally  from  the  races  that  have  attained  the 
greatest  elevation,  has  no  more  real  existence  than  that  which  has  been  supposed 
to  be  justified  by  a  difference  in  physical  characters,  and  of  which  the  fallacy  has 
been  previously  demonstrated. 

957.  The  southern  portion  of  the  African  continent  is  inhabited  by  a  group 
of  nations,  which  (as  already  mentioned)  recede  more  or  less  decidedly  from  the 
Negro  type  in  physical  characters,  and  which  seem  connected  together  by  essen- 
tial community  of  language,  as  brariches  of  the  stock  of  which  the  Kaffres  may 
be  considered  the  stem.  In  this  warlike  nomadic  people,  which  inhabit  the 
eastern  parts  of  South  Africa,  to  the  northward  of  the  Hottentot  country,  so 
great  a  departure  from  the  ordinary  Negro  type  presents  itself,  that  many  travel- 
lers have  assigned  to  them  a  different  origin.  The  degree  of  this  departure, 
however,  varies  greatly  in  the  different  Kaffre  tribes ;  for  whilst  some  of  them 
are  black,  woolly-headed,  and  decidedly  prognathous,  so  as  obviously  to  approach 
the  modified  Negroes  of  Congo  in  general  aspect,  others  recede  considerably  from 
the  typical  prognathous  races,  both  in  complexion,  features,  and  form  of  head, 
presenting  a  light-brown  colour,  a  high  forehead,  a  prominent  nose,  and  a  tall, 
robust,  well-shaped  figure.  The  thick  lips  and  black  frizzled  hair,  however, 
are  generally  retained;  though  the  hair  is  sometimes  of  a  reddish  colour,  and 
becomes  flowing;  and  the  features  may  present  a  European  cast.  But  even 
among  the  tribes  which  depart  most  widely  from  the  Negro  type,  individuals  arc 
found  who  present  a  return  to  it;  and  it  is  interesting  to  remark,  that  the  people 


844    OF  THE  BRANCHES  OF  THE  HUMAN  FAMILY. 

of  Delagoa  Bay,  though  of  the  Kaffre  race  (as  indicated  by  their  language), 
having  been  degraded  by  subjugation,  approach  the  people  of  the  Guinea  Coast 
in  their  physical  characters.  In  fact,  between  the  most  elevated  Kaffre  and  the 
most  degraded  Negro,  every  possible  gradation  of  physical  and  psychical  charac- 
ters is  presented  to  us,  as  we  pass  northwards  and  westwards  from  Kaffraria 
towards  the  Guinea  Coast;  and  we  meet  with  a  similar  transition,  although  not 
carried  to  so  great  an  extent,  as  we  pass  up  the  eastern  coast.  —  The  languages 
of  the  Kaffres  and  other  allied  tribes  are  distinguished  by  a  set  of  remarkable 
characters,  which  have  been  considered  as  isolating  them  from  other  African 
tongues.  According  to  Dr.  Latham,  however,  these  peculiarities  are  not  so  far 
without  precedent  elsewhere,  as  to  establish  the  very  decided  line  of  demarcation 
which  some  have  attempted  to  draw;  and  may  be  regarded,  in  fact,  as  resulting 
from  the  fuller  development  of  tendencies  which  manifest  themselves  in  other 
African  languages. 

958.  The  Hottentot  race  differs  from  all  other  South  African  nations,  both  in 
language  and  in  physical  conformation.  Its  language  cannot  be  shown  to  possess 
•distinct  affinities  with  any  other  stock ;'  but  in  bodily  structure  there  is  a  re- 
markable admixture  of  the  characters  of  the  Mongolian  with  those  of  the  Negro. 
Thus  the  face  presents  the  very  wide  and  high  cheek-bones,  with  the  oblique 
eyes  and  flat  nose,  of  the  Northern  Asiatics ;  at  the  same  time  that,  in  the  some- 
what prominent  muzzle  and  thick  lips,  it  resembles  the  countenance  of  the  Negro. 
The  complexion  is  of  a  tawny  buff  or  fawn  colour,  like  the  black  of  the  Negroes 
diluted  with  the  olive  of  the  Mongols.  The  hair  is  woolly,  like  that  of  the  Ne- 
groes, but  it  grows  in  small  tufts  scattered  over  the  surface  of  the  scalp  (like  a 
scrubbing-brush),  instead  of  covering  it  uniformly ;  thus  resembling  in  its  com- 
parative scautiness  that  of  the  Northern  Asiatics.  It  is  most  interesting  to 
observe  this  remarkable  resemblance  in  physical  characters,  between  the  Hotten- 
tots and  the  Mongolian  races,  in  connection  with  the  similarity  that  exists  be- 
tween the  circumstances  under  which  they  respectively  live ;  and  it  is  not  a  little 
curious  that  the  Hottentot,  as  the  Mongol,  should  be  distinguished  by  the  extra- 
ordinary acuteness  of  his  vision  (§  775).  No  two  countries  can  be  more  similar, 
than  the  vast  steppes  of  Central  Asia,  and  the  karroos  of  Southern  Africa;  and 
the  proper  inhabitants  of  each  are  nomadic  races,  wandering  through  deserts  re- 
markable for  the  wide  expansion  of  their  surface,  their  scanty  herbage,  and  the 
dryness  of  their  atmosphere,  and  feeding  upon  the  milk  and  flesh  of  their  horses 
and  cattle.  Of  the  original  pastoral  Hottentots,  however,  comparatively  few  now 
remain.  A  large  proportion  of  them  have  been  gradually  driven,  by  the  en- 
croachments of  the  Kaffres  and  of  European  colonists,  and  by  internal  wars  with 
each  other,  to  seek  refuge  among  the  inaccessible  rocks  and  deserts  of  the  in- 
terior; and  have  thus  been  converted  from  a  mild,  unenterprising  race  of 
shepherds,  into  wandering  hordes  of  fierce,  suspicious,  and  vindictive  savages, 
treated  as  wild  beasts  by  their  fellow-men,  until  they  become  really  assimilated 
to  wild  beasts  in  their  habits  and  dispositions.  Hence  have  arisen  the  tribes  of 
Bushmen  or  Bosjesmeny  which  are  generally  regarded  as  presenting  the  most  de- 
graded and  miserable  condition  of  which  the  human  race  is  capable,  and  have 
been  supposed  (but  erroneously)  to  present  resemblances  in  physical  characters 

1  It  is  considered  by  some,  that  the  Hottentot  language  is  a  degraded  Kaffre,  as  the 
Bushman  language  is  a  degraded  Hottentot ;  but  the  Author  is  informed  by  Mr.  Norris, 
that  he  sees  no  valid  ground  for  this  assumption,  the  affinities  of  the  Hottentot  language 
being  rather,  in  his  opinion,  with  the  languages  of  High  Asia,  although  the  connecting 
links  are  extremely  slight.  Such  as  they  are,  however,  they  tend  to  confirm  an  idea  sug- 
gested to  the  Author,  some  years  since,  by  the  marked  reproduction  of  so  many  Mongolian 
characters  in  the  Hottentot  race, — that  it  is  the  remnant  of  a  migration  from  Asia,  earlier 
than  that  in  which  the  great  bulk  of  the  African  nations  have  their  origin ;  and  that  it  has 
been  driven  down  to  the  remotest  corner  of  the  continent,  just  as  the  aboriginal  (Mongo- 
lian) population  of  south-western  Europe  seems  to  have  beeii  driven  back  by  the  Indo-Eu- 
ropean immigration  ($  951). 


AMERICAN    NATIONS.  845 

to  the  higher  Quadrumana.  This  transformation  has  taken  place,  under  the 
observation  of  eye-wif nesses,  in  the  Koranas,  a  tribe  of  Hottentots  well  known 
to  have  been  previously  the  most  advanced  in  all  the  improvements  which  belong 
to  pastoral  life ;  for  having  been  plundered  by  their  neighbours,  and  driven-out 
into  the  wilderness  to  subsist  upon  wild  fruits,  they  have  adopted  the  habits  of 
the  Bushmen,  arid  have  become  assimilated  in  every  essential  particular  to  that 
miserable  tribe. — It  appears,  however,  from  the  inquiries  of  Dr.  Andrew  Smith, 
that  this  process  of  degradation  has  been  in  operation  quite  independently  of 
external  agencies ;  nearly  all  the  South  African  tribes  who  have  made  any  ad- 
vances in  civilization,  being  surrounded  by  more  barbarous  hordes,  whose  abodes 
are  in  the  wildernesses  of  mountains  and  forests,  and  who  constantly  recruit  their 
numbers  by  such  fugitives  as  crime  and  destitution  may  have  driven  from  their 
own  more  honest  and  more  thriving  communities;  and  these  people  vary  their 
mode  of  speech  designedly,  and  even  adopt  new  words,  in  order  to  make  their 
meaning  unintelligible  to  all  but  the  members  of  their  own  association.  This 
has  its  complete  parallel  in  the  very  midst  of  our  own  or  any  other  highly-civil- 
ized community  ;  all  our  large  towns  containing  spots  nearly  as  inaccessible  to 
those  unacquainted  with  them,  as  are  the  rude  caves  or  clefts  of  hills,  or  the  bur 
rows  scooped-out  of  the  level  karroo,  in  which  the  wretched  Bushman  lies  in  wait 
for  his  prey  ;  and  these  being  tenanted  by  a  people  that  have  been  well  charac- 
terized as  les  classes  danyereuses,  which,  as  often  as  the  arm  of  the  law  is  para^ 
lyzed,  issue-forth  from  the  unknown  deserts  within  which  they  lurk,  and  rival  in 
their  fierce  indulgence  of  the  most  degrading  passions,  and  in  their  excesses  of  wan- 
ton cruelty,  the  most  terrible  exhibitions-of  barbarian  inhumanity.  Such  outcasts, 
in  all  nations,  purposely  adopt,  like  the  Bushmen,  a  'flash'  language;  and  in 
their  general  character  and  usages,  there  is  a  most  striking  parallel.' 

959.  The  American  nations,  taken  collectively,  form  a  group  which  appeals  to 
have  existed  as  a  separate  family  of  nations  from  a  very  early  period  in  the  world's 
history.  They  do  not  form,  however,  so  distinct  a  variety,  in  regard  to  physical 
characters,  as  some  anatomists  have  endeavoured  to  prove ;  for,  although  certain 
peculiarities  have  been  stated  to  exist  in  the  skulls  of  the  aboriginal  Americans, 
yet  it  is  found  on  a  more  extensive  examination,  that  these  peculiarities  are  very 
limited  in  their  extent, — the  several  nations  spread  over  this  vast  continent,  dif- 
fering from  each  other  in  physical  peculiarities,  as  much  as  they  do  from  those 
of  the  Old  World,  so  that  no  typical  form  can  be  made-out  among  them.  In 
regard  to  complexion,  again,  it  may  be  remarked,  that  although  the  native 
Americans  have  been  commonly  characterized  as  "  red  men,"  they  are  by  no 
means  invariably  of  a  red  or  coppery  hue,  some  being  as  fair  as  many  European 
nations,  others  being  yellow  or  brown,  and  others  nearly,  if  not  quite,  as  black  as 
the  Negroes  of  Africa;  whilst,  on  the  other  hand,  there  are  tribes  equally  red, 
and  perhaps  more  deserving  that  epithet,  in  Africa  and  Polynesia.  Our  ordinary 
notion  of  the  American  races  having  been  chiefly  founded  upon  the  characters  of 
those  tribes  of  i  Indians'  with  whom  European  settlers  first  came  into  contact, 
proves  to  be  no  more  applicable  to  the  inhabitants  of  the  Continent  generally,  than 
are  the  characters  of  the  Negro  to  the  population  of  Africa  as  a  whole  (§  955). — • 
In  spite  of  all  this  diversity  of  conformation,  it  is  believed  that  the  structure  of 
their  languages  affords  a  decided  and  clearly-marked  evidence  of  relationship  be- 
tween them  (§  949).  Notwithstanding  their  diversities  in  mode  of  life,  too, 
there  are  peculiarities  of  mental  character,  as  well  as  a  number  of  ideas  and  cus- 
toms derived  from  tradition,  which  seem  to  be  common  to  them  all ;  and  which 
for  the  most  part  indicate  a  former  elevation  in  the  scale  of  civilization,  that  has 
left  its  traces  among  them  even  in  their  present  depressed  condition,  and  still  distin- 
guishes them  from  the  sensual,  volatile,  and  almost  animalized  savages,  that  are 
to  be  met-with  in  many  parts  of  the  Old  Continent. — The  Esquimaux  have  been 
regarded  as  constituting  an  exception  to  all  general  accounts  of  the  physical  cha- 
1  See  "London  Labour  and  the  London  Poor,"  p.  2. 


846         OF    THE    BRANCHES    OP    THE    HUMAN    FAMILY. 

racters  of  the  American  nations ;  for  in  the  configuration  of  their  skulls,  as  also 
in  their  complexion  and  general  physiognomy,  they  conform  to  the  Mongolian 
type,  even  presenting  it  in  an  exaggerated  degree ;  whilst  their  wide  extension 
aiong  the  whole  northern  coast  of  America ;  through  the  Aleutian  Islands,  and 
even  to  the  Continent  of  Asia,  certainly  lend  weight  to  the  idea  that  they  derive 
their  origin  from  the  Northern  Asiatic  stock.  But  the  increased  acquaintance 
which  has  been  recently  gained  with  the  tribes  that  people  the  north-eastern  por- 
tion of  the  American  Continent,  has  clearly  shown  that  no  physical  separation 
can  be  established  between  the  Esquimaux  and  the  Indian  proper;  the  one  form 
graduating  so  insensibly  into  the  other  as  to  make  the  distinction  between  the 
two  groups  as  difficult,  as  on  the  western  side  it  is  easy.  Hence  the  existence  of 
the  Esquimaux  population  in  this  situation,  affords  a  complete  link  of  transition 
between  the  Asiatic  and  the  American  nations,  in  the  precise  region  in  which  the 
geographical  relations  of  the  two  continents  would  lead  us  to  expect  it. 

960.  It  now  remains  for  us  to  notice  the    Oceanic  races,  which  inhabit  the 
vast  series  of  islands  scattered  through  the  great  ocean  that  stretches  from  Mada- 
gascar to  Ea.ster  Island.     There  is  no  part  of  the  world  which  affords  a  greater 
variety  of  local  conditions  than  this,  or  which  more  evidently  exhibits  the  effects 
of  physical  agencies  on  the  organization  of  the  human  body.     Moreover,  it  affords 
a  case  for  the  recognition  of  affinities  by  means  of  language,  that  possesses  unusual 
stability;  since  the  insulated  position  of  the  various  tribes  that  people  the  remote 
spots  of  this  extensive  tract,  prevents  them  from  exercising  that  influence  upon 
each  other's  form  of  speech,  which  is  to  be  observed  in  the  case  of  nations  united 
by  local  proximity  or  by  frequent  intercourse.     Tried  by  this  test,  it  is  found  that 
the  different  groups  of  people  inhabiting  the  greater  part  of  these  insular  regions, 
although  so  widely  scattered  and  so  diverse  in  physical  characters,  are  more  nearly 
connected  together  than  most  of  the  families  of  men  occupying  continuous  tracts 
of  land  on  the  great  continents  of  the  globe. — The  inhabitants  of  Oceania  seem 
divisible  into  two  principal  groups,  which  are  probably  to  be  regarded  as  having  con- 
stituted distinct  races  from  a  very  early  period ;  these  are  the  Malayo-Polynesian 
race,  and  the  Negritos  or  Pelagian  Negroes. 

961.  The  Malayo-Polynesian  group  is  by  far  the  more  extensive  of  the  two; 
and  comprehends  the  inhabitants  of  the  greater  part  of  the  Indian  and  Polynesian 
Archipelagoes,  with  the  peninsula  of  Malacca  (which  is  the  centre  of  the  Malays 
proper),  and  perhaps  the  inhabitants  of  Madagascar.    These  are  all  closely  united 
by  affinities  of  language.     The  proper  Malays  bear  a  strong  general  resemblance 
to  the  Mongolian  races,  and  this  resemblance  is  shared,  in  a  greater  or  less  degree, 
by  most  of  the  inhabitants  of  the  Indian  Archipelago.     They  are  of  a  darker 
complexion,  as  might  be  expected  from  their  proximity  to  the  equator;  but  in  this 
complexion,  yellow  is  still  a  large  ingredient.    The  Polynesian  branch  of  the  group 
presents  a  much  wider  diversity;  and  if  it  were  not  for  the  community  of  lan- 
guage, it  might  be  thought  to  consist  of  several  races,  as  distinct  from  each  other 
as  from  the  Malayan  branch.     Thus  the  Tahitians  and  Marquesans  are  tall  and 
well-made;  their  figures  combine  grace   and   vigour;  their  skulls    are    usually 
remarkably  symmetrical;  and  their  physiognomy  presents  much  of  the  European 

,cast,  with  a  very  slight  admixture  of  the  features  of  the  Negro.  The  complexion, 
especially  in  the  females  of  the  higher  classes,  who  are  sheltered  from  the  wind 
and  sun,  is  of  a  clear  olive  or  brunette,  such  as  is  common  among  the  natives  of 
Central  and  Southern  Europe;  and  the  hair,  though  generally  black,  is  sometimes 
brown  or  auburn,  or  even  red  or  flaxen.  Among  other  tribes,  as  the  New  Zeal- 
anders,  and  the  Tonga  and  Friendly  Islanders,  there  are  greater  diversities  of  con- 
formation and  hue ;  some  being  finely  proportioned  and  vigorous,  others  com- 
paratively small  and  feeble ;  some  being  of  a  copper-brown  colour,  others  nearly 
black,  others  olive,  and  others  almost  white.  In  fact,  if  we  once  admit  a  strongly- 
marked  difference  in  complexion,  features,  hair,  and  general  configuration,  as 
establishing  a  claim  to  original  distinctness  of  origin,  we  must  admit  the  applica- 


PAPUAN,    AND    ALFORIAN    RACES.  847 

tion  of  this  hypothesis  to  almost  every  group  of  islands  in  the  Pacific ; — an  idea, 
of  which  the  essential  community  of  language  seems  to  afford  a  sufficient  refuta- 
tion. Among  the  inhabitants  of  Madagascar,  too,  all  of  which  speak  dialects  of 
the  same  language,  some  bear  a  strong  resemblance  to  the  Malayan  type,  whilst 
others  present  approaches  to  that  of  the  Negro. 

962.  The  Negrito,  or  Pelagian-Negro  races  must  be  regarded  as  a  group  alto- 
gether distinct  from  the  preceding  ;  having  a  marked  diversity  of  language  ;  and 
presenting,  more  decidedly  than  any  of  the  Malayo-Polynesian,  the  characters  of 
the  Negro  type.     They  form  the  predominating  population  of  New  Britain,  New 
Ireland,  the  Louisiade  and  Solomon  Isles,  of  several  of  the  New  Hebrides,  and 
of  New  Caledonia;  and  they  seem  to  extend  westwards  into  the  mountainous  in- 
terior of  the  Malayan  Peninsula,  and  into  the  Andaman  Islands  in  the  Bay  of  Ben- 
gal.   The  Tasmanians,  or  aborigines  of  Van  Dieman's  Land,  which  are  now  almost 
completely  exterminated,  undoubtedly  belonged    to  this  group.     Very  little  is 
known  of  them,  except  through  the  reports  of  the  people  of  the  Malayo-Polynesian 
race  inhabiting  the  same  islands;  but  it  appears  that,  generally  speaking,  they 
have  a  very  inferior  physical  development,  and  lead  a  savage  arid  degraded  life. 
There  is  considerable  diversity  of  physical  characters  among  them ;    some  ap- 
proximating  closely    in    hair,    complexion,    and    features,   to    the   Guinea-Coast 
Negroes;  whilst  others  are  of  yellower  tint,  straight   hair,  and   better  general 
development.     The  Papuans,  who  inhabit  the  northern  coast  of  New-Guinea  and 
some  adjacent  islands,  and  who  are  remarkable  for  their  large  bushy  masses  of 
half-woolly  hair,  have  been  supposed  to  constitute  a  distinct  race ;  but  there  is 
little  doubt  that  they  are  of  hybrid  descent,  between  the  Malays  and  the  Pelagian 
Negroes. — To  this  group  we  are  probably  to  refer  the  Alforous,  or  Alforian  race, 
which  are  considered  by  some  to  be  the  earliest  inhabitants  of  the  greater  part  of 
the  Malayan  Archipelago,  and  to  have  been  supplanted  by  the  more  powerful 
people  of  the  preceding  races,  who  have  either  extirpated  them  altogether,  or 
have  driven  them  from  the  coasts  into  the  mountainous  and  desert  parts  of  the 
interior.    They  are  yet  to  be  found  in  the  central  parts  of  the  Moluccas  and  Philip. 
pines ;  and  they  seem  to  occupy  most  of  the  interior  and  southern  portion  of 
New  Guinea,  where  they  are  termed  Endamenes.     They  are  of  very  dark  com- 
plexion ;  but  their  hair,  though  black  and  thick,  is  lank.    They  have  a  peculiarly 
repulsive  physiognomy ;  the  nose  is  flattened,  so  as  to  give  the  nostrils  an  almost- 
transverse  position;  the  cheek-bones  project;  the  eyes  are  large,  the  teeth  promi- 
nent, the  lips  thick,  and  the  mouth  wide.     The  limbs  are  long,  slender,  and  mis- 
shapen.    From  the  close  resemblance  in  physical  characters  between  the  Enda- 
menes of  New  Guinea  and  the  aborigines  of  New  Holland,  and  from  the  proximity 
between  the  adjacent  coasts  of  these  two  islands,  it  may  be  surmised  that  the 
latter  belong  to  the  Alforian  race ;  but  too  little  is  known  of  the  language  of 
either,  to  give  this  inference  a  sufficient  stability.     In  the  degradation  of  their 
condition  and  manner  of  life,  the  savages  of  New  Holland  fully  equal  the  Bush- 
men of  South  Africa;  and  it  is  scarcely  possible  to  imagine  human  beings,  exist- 
ing in  a  condition  more  nearly  resembling  that  of  brutes.    But  there  is  reason  to 
believe,  that  the  tribes  in  closest  contact  with  European  settlers  are  more  miser- 
able and  savage  than  those  of  the  interior;  and  even  with  respect  to  these,  in- 
creasing acquaintance  with  their  language,  and  a  consequent  improved  insight 
into  their  modes  of  thought,  tend  to  raise  the  very  low  estimate  which  has  been 
formed  and  long  maintained,  in  regard  to  their  extreme  mental  degradation.    The 
latest  and  most  authentic  statements  enable  us  to  recognize  among  them  the  same 
principles  of  a  moral  and  intellectual  nature,  which,  in  more  cultivated  tribes, 
constitute  the  highest  endowments  of  humanity ;  and  thus  to  show  that  they  are 
not  separated  by  any  impassable  barrier  from  the  most  civilized  and  elevated 
nations  of  the  globe. — There  are  many  indications,  indeed,  that  the  Negrito  race 
is  not  so  radically  distinct  from  the  Malayo-Polynesian,  as  the  marked  physical 
dissimilarity  of  their  respective  types,  and  the  apparent  want  of  conformity  be- 


848  CHARACTERISTICS    OF    DIFFERENT    AGES. 

tween  their  languages,  would  make  it  appear.  For  as,  on  the  one  hand,  some 
of  the  subdivisions  of  the  latter  present  a  decided  tendency  towards  that  progna- 
thous character  and  depth  of  complexion  which  are  typical  of  the  former,  so 
among  the  former  do  we  not  unfrequently  meet  with  a  lighter  shade  of  skin,  a 
greater  symmetry  of  skull,  and  a  considerable  improvement  in  form  and  feature. 
And  although  no  very  close  relationship  can  be  discovered  between  the  Negrito 
and  Malayo-Polynesian  languages,  yet  it  has  been  pointed-out  by  Mr.  Norris  that 
a  much  more  decided  relationship  exists  between  the  Australian  and  Tamulian 
(§  954);  and  remote  as  this  connection  seems,  the  circumstance  adds  weight  to 
the  idea,  that  the  native  Australian  (with  other  Negrito  tribes)  are  an  offset 
from  that  southern  branch  of  the  great  nomadic  stock  of  Central  Asia,  which 
seems  early  to  have  spread  itself  through  the  Indo-Chinese  and  the  Indian 
Peninsulas,  and  to  have  even  there  shown  an  approximation  to  the  prognathous 
type.1 

963.  Looking,  then,  to  the  great  diversity  which  exists  among  the  subordinate 
groups  of  which  both  these  divisions  consist,  and  their  tendency  to  mutual  ap- 
proximation, it  cannot  be  shown  that  any  sufficient  reason  exists  for  isolating 
them  from  each  other;  and,  as  already  remarked  (§  961),  there  seems  no  medium 
between  the  supposition  that  each  island  had  its  aboriginal  pair  or  pairs,  and  the 
doctrine  that  the  whole  of  Oceania  has  been  peopled  from  a  common  stock. 
Looking,  again,  to  the  very  decided  approximation  which  is  presented  by  certain 
Oceanic  tribes  to  the  Mongolian  type,  and  this  in  localities  which,  on  other 
grounds,  might  be  regarded  as  having  received  the  first  stream  of  migration,  the 
possibility,  to  say  the  least,  can  scarcely  be  denied,  that  the  main-land  furnished 
the  original  stock,  which  has  undergone  various  transformations  subsequently  to 
its  first  dispersion ;  these  having  been  the  result  of  climatic  influence  and  mode 
of  life,  and  having  been  chiefly  influenced  as  to  degree,  by  the  length  of  time 
during  which  the  transforming  causes  have  been  in  operation.  At  any  rate  it 
may  be  safely  affirmed,  that  the  Oceanic  races  are  not  entitled  by  any  distinctive 
physical  peculiarity,  to  rank  as  a  group  which  must  have  necessarily  had  an  ori- 
ginal stock  distinct  from  that  of  the  Continental  nations. 


CHAPTER  XVIII. 

OP   THE   MODES   OP  VITAL   ACTIVITY  CHARACTERISTIC   OF  DIFFERENT   AGES. 

964.  Although  from  the  time  when  the  Human  being  comes  into  the  world, 
to  the  final  cessation  of  his  corporal  existence,  the  various  functional  operations 
of  Organic  life  are  carried-on  with  ceaseless  activity,  whilst  those  of  Animal  life 
are  only  suspended  by  the  intervals  of  repose  which  are  needed  for  the  renovation 
of  their  organs,  yet  there  are  very  marked  differences,  not  only  in  the  degree  of 
their  united  activity,  but  also  in  the  relative  degrees  of  energy  which  they  sever- 
ally manifest,  at  different  epochs.  These  differences,  taken  in  connection  with 
the  modifications  in  the  size  and  conformation  of  the  body  with  which  they  are 
in  relation,  mark-out  the  whole  term  of  life  into  the  various  'Ages,'  which  are 
commonly  recognized  as  seven,  namely  Infancy,  Childhood,  Youth,  Adolescence, 
Manhood,  Decline,  and  Senility.  For  Physiological  purposes,  however,  a  less 
minute  subdivision  is  equally  or  perhaps  more  appropriate ;  namely  the  three 
great  periods  of  Growth  and  Development,  of  Maturity,  and  of  Decline.  The 
first  comprehends  the  whole  of  that  series  of  operations,  by  which  the  germ 
evolves  itself,  at  the  expense  of  the  nutriment  which  it  appropriates  from  ex- 

1  Some  very  interesting  speculations,  based  on  the  most  recent  information,  respecting 
the  mode  in  which  the  great  Oceanic  region  has  been  peopled,  are  put-forth  by  Dr.  Latham 
on  •'  Orr's  Circle  of  the  Sciences,"  vol.  i.  pp.  341-349. 


PERIOD    OF    GROWTH    AND    DEVELOPMENT.  840 

ternal  sources,  into  the  complete  organism,  possessed  not  merely  of  its  full 
dimensions,  but  of  its  highest  capacity  for  every  kind  of  functional  activity ;  this 
includes,  therefore,  the  epochs  of  Embryonic  life,  Infancy,  Childhood,  Youth, 
and  Adolescence,  all  of  which  are  characterized  by  an  excess  of  the  constructive 
over  the  destructive  changes  taking-place  in  the  organism.  The  second  period 
ranges  over  the  whole  term  of  Manhood,  in  which,  the  organism  having  attained 
its  complete  development,  is  brought  into  vigorous  and  sustained  activity  ;  and 
in  which  it  is  maintained  in  a  condition  fitted  for  such  activity,  by  the  equilibrium 
which  subsists  between  the  operations  of  redintegration  and  of  disintegration. 
The  third  period  commences  with  the  incipient  failure  of  the  bodily  powers,  con- 
sequent upon  the  diminished  activity  of  the  constructive  powers,  as  compared 
with  that  of  the  changes  which  involve  degeneration  and  decay  ;  this  diminution 
begins  to  manifest  itself  during  the  latter  part  of  Middle  Life,  before  Old  age 
can  properly  be  said  to  commence;  and  it  continues  in  an  increasing  ratio,  through 
the  whole  l  decline  of  life/  until,  the  reparative  powers  being  exhausted,  Death 
supervenes  as  the  necessary  termination  of  that  long  succession  of  phenomena 
of  which  Life  consists. 

965.  Although  the  organization  of  the  body  at  each  epoch  may  be  truly  said 
to  be  the  resultant  of  all  the  material  changes  which  it  has  undergone  during 
the  preceding  periods,  yet  it  is  scarcely  possible  to  take  an  enlarged  view  of  the 
case,  without  perceiving  that  we  must  look  for  the  cause  of  this  succession  in 
those  dynamical  conditions,  the  presence  of  which  is  the  distinguishing  attribute 
of  living  structures.     Every  constructive  act,  whether  this  consist  in  Growth 
(§  431)  or  in  Development  (§  342),  not  merely  requires  materials  for  the  new 
tissue  produced,  but  depends  upon  the  active  operation  of  a  formative  power,  with- 
out whose  agency  these  materials  would  remain  unorganized.     When  we  examine 
(See  PRINC!  OF  GEN.  PHYS.  Am.  Ed.)  into  the  source  of  the  formative  power 
which  we   thus  see   operating  in  every  individual  organism,  we  find  that  it  is 
chiefly  traceable  to  the  Physical  Forces  to  which  it  is  subjected  (Heat  being  the 
one  which  seems  to  bear  most  directly  upon  the  formative  operations) ;  these 
forces  being  metamorphosed,  so  to  speak,  into  the  constructive  force  of  the  living 
body,  in  virtue  of  the  peculiar  endowments  of  its  material  substratum, — just  as 
an  Electric  current  transmitted  through  the  different  nerves  of  Sense,  produces 
the  sensory  impressions  which  are  characteristic  of  each  respectively  (§  731);  or  as 
the  same  current,  transmitted  through  one  form  of  Inorganic  matter,  produces 
Light  and  Heat,  through  another,  Chemical  Change,  or  through  another,  Mag- 
netism.    But  we  must  also  recognize  in  the  Organism  at  large,  as  well  as  in  every 
integral   part  of  it  (§  340),  a  certain   capacity  for  growth  and  development, — 
which  is  the  original  endowment  of  its  germ, — which  not  only  determines  the 
mode  in  which  it  shall  progressively  evolve  itself  into  the  fabric  characteristic  of 
its  species  and  sex,  but  also  shapes  the  peculiarities  of  the  individual, — which 
serves  also  to  bring-about  the  perpetual  reconstruction  that  is  needed  for  its  con- 
tinued maintenance,  and  is  peculiarly  manifested  in  those  reparative  processes 
which  make-good  losses  of  its  substance  resulting  from  injury  or  disease, — and 
of  which  the  cessation,  by  preventing  any  further  metamorphosis  of  Physical  into 
Vital  force,  causes  the  constructive  powers  to  fail  altogether,  so  that  the  Organism 
is  resolved-back  by  these  very  forces,  into  the  various  forms  of  Inorganic  matter 
at  the  expense  of  which  it  had  been  built-up. 

966.  Now  this  'germinal  capacity'  is  most  strikingly  displayed  during  those 
earliest  periods  of  existence,  in  which  growth  and  development  alike  are  taking- 
place  most  rapidly;  in  fact,  the  further  we  go  back  in  the  history  of  intra-uterine 
life,  the  more  energetic  do  we  perceive  its  manifestations  to  be.     For  when  we 
look  simply  at  the  increase  from  the  minute  point  that  constitutes  the  first  per- 
ceptible germ,  to  the  mature  foetus  of  6  or  7  Ibs.  weight,  we  see  that  at  no  other 
period  of  existence  can  that  increase  be  compared  in  its  rate,  with  that  which 
presents  itself  during  the  nine  months  that  follow  conception ;  and  if  we  go  more 

54 


850  CHARACTERISTICS    OF    DIFFERENT    AGES. 

into  detail,  we  find  that  it  is  yet  more  remarkable  in  the  earlier  than  in  the  latei 
months  (§  968).  So,  again,  it  is  in  the  first  few  weeks  of  embryonic  life,  that 
the  foundation  is  laid  of  most  of  its  permanent  organs,  in  the  midst  of  an  ap- 
parently-homogeneous mass  of  cells ;  whilst  in  the  succeeding  weeks,  these  rudi- 
ments are  evolved  into  the  semblance  of  the  forms  they  are  subsequently  to 
present,  and  a  differentiation  of  tissues  begins  to  show  itself  in  their  several  parts ; 
so  that  the  developmental  process  is  so  far  advanced  at  little  more  than  half  the 
term  of  gestation,  that  the  foetus  may  even  then,  under  favourable  circumstances, 
maintain  an  independent  existence  (§  876).  The  rate  of  increase  becomes  pro- 
gressively slower,  during  the  advance  from  infancy  to  maturity ;  and  the  energy 
of  the  developmental  processes  is  comparatively  enfeebled,  being  limited  to  the 
perfecting  of  structures  whose  foundations  had  been  previously  laid,  and  in  no 
instance  manifesting  itself  normall^  in  the  evolution  of  a  new  part  or  organ. 
Now  as  there  is  no  limit  (in  the  well-nourished  individual)  to  the  supply  of  Food 
and  Warmth,  it  follows  that  this  gradual  decline  of  formative  activity  must  be 
due  to  a  diminution  of  the  capacity  for  that  activity,  inherent  in  the  organism 
itself;  and  this  diminution  is  still  more  strongly  marked  by  that  entire  cessation, 
both  of  increase,  and  of  further  developmental  changes,  which  constitutes  the 
termination  of  the  first  period.  For  the  organism  which  has  attained  that  stage 
of  its  existence,  has  so  far  lost  the  formative  capacity  which  characterized  its 
earlier  years,  that,  however  copious  the  supply  of  food,  however  abundant  the 
generation  of  heat,  it  can  thenceforth  do  no  more  than  maintain  its  normal  con- 
dition, and  can  effect  this  for  only  a  limited  term  of  years.  It  seems  a  necessary 
sequence  of  this  series  of  phenomena,  that  the  time  should  come,  when,  after  a 
period  of  gradual  decline,  the  germinal  capacity  of  the  organism  should  be  so 
much  reduced  as  no  longer  to  suffice  for  the  maintenance  of  its  own  integrity ; 
and  whenever  such  is  the  case,  the  termination  of  its  existence  as  a  living  body 
must  be  the  necessary  result.  Hence  we  find  that  there  is  a  natural  limit,  not 
only  to  the  size  and  development  of  the  organism,  but  also  to  the  duration  of  its 
life.  And  although  that  limit,  in  each  case,  is  subject  to  variation  amongst  in- 
dividuals, partly  in  consequence  of  diversity  of  external  conditions,  but  partly 
(it  may  be  surmised)  through  differences  in  the  measure  of  germinal  capacity 
possessed  by  each,  yet  there  is  a  limit  also  to  these  variations,  so  that  the  character 
of  the  species  is  never  departed-from. 

967.  Period  of  Growth  and  Development. — The  general  history  of  the  first 
part  of  this  period,  that  of  Embryonic  existence,  has  already  been  so  fully  given, 
that  it  is  only  necessary  here  to  remark  briefly  in  regard  to  the  character  of  its 
vital  operations,  that  the  whole  nisus  of  its  activity  is  directed  rather  to  the  per- 
formance of  the  vegetative  or  organic  than  to  that  of  the  animal  functions;  the 
action  of  the  heart,  and  the  occasional  reflex  movements  of  the  limbs,  being  its 
only  manifestations  of  nervo-muscular  power.  And  thus  it  seems  to  be,  that  the 
formative  capacity  is  greater  during  embryonic  life,  than  at  any  subsequent  pe- 
riod, and  greater  in  its  earlier  than  in  its  later  stages ;  so  that  we  have  not  only 
evidence  of  an  extraordinary  power  of  regenerating  parts  which  have  been  lost  by 
disease  or  accident,  as  seen  in  attempts  at  the  reproduction  of  entire  limbs  after 
their  < spontaneous  amputation'  (§  359);  but  there  is  also  not  unfrequently  an 
absolute  excess  of  productive  power,  as  shown  in  the  development  of  supernume- 
rary organs,  which  may  even  proceed  to  the  extent  of  the  complete  duplication 
of  the  entire  body,  by  the  early  subdivision  of  the  embryonic  structure  into  two 
independent  halves  (§  355). — It  is  to  be  noticed,  also,  that  the  embryo  derives 
its  supply  not  merely  of  food  but  also  of  heat,  from  its  maternal  parent ;  and  it  is 
probably  owing  especially  to  the  constancy  with  which  this  force  operates,  that 
the  period  of  embryonic  development  is  so  uniform  in  Man  (as  in  warm-blooded 
Animals  generally),  by  comparison  with  the  corresponding  developmental  periods 
in  Plants  and  cold-blooded  Animals,  these  being  entirely  determined  by  the  de- 
gree of  heat  to  which  the  embryoes  are  subjected. 


F  <E  T  A  L    LIFE    AND    INFANCY.  851 

968.  It  is  frequently  of  great  importance,  both  to  the  Practitioner  and  to  the 
Medical  Jurist,  to  be  able  to  determine  the  age  of  a  Foetus,  from  the  physical 
characters  which  it  presents;  and  the  following  table  has  been  framed  by  Dever- 
gie1  in  order  to  facilitate  such  determination.  It  is  to  be  remarked,  however, 
that  the  absolute  length  and  weight  of  the  Embryo  are  much  less  safe  criteria,  than 
its  degree  of  development,  as  indicated  by  the  relative  evolution  of  the  several 
parts  which  make  their  appearance  successively.  Thus  it  is  very  possible  for  one 
child,  born  at  the  full  time,  to  weigh  less  than  another,  born  at  8  or  even  at  7 
months ;  its  length,  too,  may  be  inferior :  and  even  the  position  of  the  middle 
point  of  the  body  is  not,  taken  alone,  a  safe  criterion,  since  it  is  liable  to  varia- 
tion in  individuals.2 

Embryo  3  to  4  weeks. — It  has  the  form  of  a  serpent; — its  length  from  3  to  5  lines;  its 
head  indicated  by  a  swelling; — its  caudal  extremity  (in  which  is  seen  a  white  line,  indi- 
cating the  continuation  of  the  medulla  spinahs),  slender,  and  terminating  in  the  umbilical 
cord; — the  mouth  indicated  by  a  cleft,  the  eyes  by  two  black  points; — members  begin  to 
appear  as  nipple-like  protuberances; — liver  occupies  the  whole  abdomen  ; — the  bladder  is 
very  large.  The  chorion  is  villous,  but  its  villosities  are  still  diffused  over  the  whole 
surface. 

Embryo  of  6  weeks. — Its  length  from  7  to  10  lines; — its  weight  from  40  to  75  grains  ; — 
face  distinct  from  cranium; — aperture  of  nose,  mouth,  eyes,  and  ears  perceptible; — head 
distinct  from  thorax ; — hands  and  fore-arms  in  the  middle  of  the  length,  fingers  distinct ; 
— legs  and  feet  situated  near  the  anus ; — clavicle  and  maxillary  bone  present  a  point  of 
ossification ; — distinct  umbilicus  for  attachment  of  cord,  which  at  that  time  consists  of  the 
omphalo-meseraic  vessels,  of  a  portion  of  the  urachus,  of  a  part  of  the  intestinal  tube,  and 
of  filaments  which  represent  the  umbilical  vessels.  The  placenta  begins  to  be  formed; — 
the  chorion  still  separated  from  the  amnion ;  the  umbilical  vesicle  very  large. 

Embryo  of  2  months. — Length  from  16  to  19  lines; — weight  from  150  to  300  grains; — 
elbows  and  arms  detached  from  the  trunk; — heels  and  knees  also  isolated; — rudiments  of 
the  nose  and  of  the  lips ;  palpebral  circle  beginning  to  show  itself; — clitoris  or  penis  appa- 
rent;— anus  marked  by  a  dark  spot; — rudiments  of  lungs,  spleen,  and  supra-renal  cap- 
sules;— caecum  placed  behind  the  umbilicus; — digestive  canal  withdrawn  into  the  abdo- 
men ; — urachus  visible ; — osseous  points  in  the  frontal  bone  and  in  the  ribs. — Chorion  com- 
mencing to  touch  the  amnion  at  the  point  opposite  the  insertion  of  the  placenta ;  placenta 
begins  to  assume  its  regular  form  ; — umbilical  vessels  commence  twisting. 

Embryo  o/3  months. — Length  from  2  to  2^  inches; — weight  from  1  oz.  to  1£  oz.  (Troy); 
— head  voluminous ; — eyelids  in  contact  by  their  free  margin ; — membrana  pupillaris  visi- 
ble ; — mouth  closed; — fingers  completely  separated; — inferior  extremities  of  greater  length 
than  rudimentary  tail ; — clitoris  and  penis  very  long; — thymus  as  well  as  supra-renal  cap- 
sules present ; — caecum  placed  below  the  umbilicus ; — cerebrum  5  lines,  cerebellum  4  lines, 
medulla  oblongata  1^  line,  and  medulla  spinalis  ^  of  a  line,  in  diameter; — two  ventricles 
of  heart  distinct. — The  decidua  reflexa  and  decidua  uterina  in  contact ; — funis  contains 
umbilical  vessels  and  a  little  of  the  gelatine  of  Warthon ; — placenta  completely  isolated  ; — 
umbilical  vesicle,  allantois,  and  omphalo-meseraic  vessels  have  disappeared. 

Fottus  o/4  months. — Length  5  to  6  inches; — weight  2£  to  3  oz. ; — skin  rosy,  tolerably 
dense  ; — mouth  very  large  and  open : — membrana  pupillaris  very  evident ; — nails  begin  ta 
appear; — genital  organs  and  sex  distinct; — caecum  placed  near  the  right  kidney; — gall- 
bladder appearing ; — meconium  in  duodenum ; — caecal  valve  visible ; — umbilicus  placed 
near  pubis ; — ossicula  auditoria  ossified  ; — points  of  ossification  in  superior  part  of  sacrum  , 
— membrane  forming  at  point  of  insertion  of  placenta  on  uterus ; — complete  contact  of  cho- 
rion with  amnion. 

Fcetus  of  5  months. — Length  6  to  7  inches ; — weight  5  to  7  oz. ; — volume  of  head  still 
comparatively  great; — nails  very  distinct; — hair  beginning  to  appear; — skin  without  se- 
baceous covering; — white  substance  in  cerebellum; — heart  and  kidneys  very  voluminous, 
— caecum  situated  at  inferior  part  of  right  kidney; — gall-bladder  distinct; — germs  of  per- 
manent teeth  appear ;  points  of  ossification  in  pubis  and  calcaneum  ; — meconium  has  a 
yellowish-green  tint,  and  occupies  commencement  of  large  intestine. 

Foetus  0/6  months. — Length  9  to  10 inches; — weight  1  Ib. ; — skin  presents  some  appear- 
ance of  fibrous  structure  ; — eyelids  still  agglutinated,  and  membrana  pupillaris  remains ; 
— sacculi  begin  to  appear  in  colon ; — funis  inserted  a  little  above  pubis ; — face  of  a  pur- 
plish red; — hair  white  or  silvery; — sebaceous  covering  begins  to  present  itself; — meco- 

1  "Me'decine  Le"gale,"  3ieme  edit.  torn.  i.  p.  279. 

a  See,  on  this  last  point,  Moreau  in  "  Lancette  Fra^aise,"  1837;  and  Dr.  A.  Taylor  in 
"  Guy's  Hospital  Reports,"  1842. 


852  CHARACTERISTICS    OF    DIFFERENT    AGES 

nium  in  large  intestine; — liver  dark-red  ; — gall-bladder  contains  serous  fluid  destitute  of 
bitterness  ; — testes  near  kidneys ; — points  of  ossification  in  four  divisions  of  sternum  ; — 
Middle  point  at  lower  end  of  sternum. 

Foetus  of  7  months. — Length  13  to  15  inches; — weight  3  to  4  Ibs. ; — skin  of  rosy  hue, 
thick,  and  fibrous  ; — sebaceous  covering  begins  to  appear ; — nails  do  not  yet  reach  extre- 
mities of  fingers  ; — eyelids  no  longer  adherent ; — membrana  pupillaris  disappearing ; — a 
point  of  ossifisation  in  the  astralagus ; — meconium  occupies  nearly  the  whole  of  large  in- 
testine ; — valvulae  conniventes  begin  to  appear; — caecum  placed  in  right  iliac  fossa; — left 
lobe  of  liver  almost  as  large  as  right ; — gall-bladder  contains  bile  ; — brain  possesses  more 
consistency ; — testicles  more  distant  from  kidneys ; — middle  point  at  a  little  below  end  of 
sternum. 

F&tus  of  8  months. — Length  14  to  16  inches; — weight  4  or  5  IDS.; — skin  covered  with 
well-marked  sebaceous  envelope  ; — nails  reach  extremities  of  fingers ; — membrana  pupil- 
laris becomes  invisible  during  this  month ; — a  point  of  ossification  in  last  vertebra  of  sac- 
rum;— cartilage  of  inferior  extremity  of  femur  presents  no  centre  of  ossification: — brain 
has  some  indications  of  convolutions  ; — testicles  descend  into  internal  ring: — middle  point 
nearer  the  umbilicus  than  the  sternum. 

Foetus  o/9  months,  the  full  term. — Length  from  17  to  21  inches; — weight  from  5  to  9  Ibs., 
the  average  probably  about  6^  Ibs. ; — head  covered  with  hair  in  greater  or  less  quantity, 
of  from  9  to  12  lines  in  length; — skin  covered  with  sebaceous  matter,  especially  at  bends 
of  joints ; — membrana  pupillaris  no  longer  exists  ; — external  auditory  meatus  still  cartila- 
ginous;— four  portions  of  occipital  bone  remain  distinct; — os  hyoides  not  yet  ossified: — 
point  of  ossification  in  the  centre  of  cartilage  at  lower  extremity  of  femur ; — white  and 
grey  substances  of  brain  become  distinct; — liver  descends  to  umbilicus; — testes  have 
passed  inguinal  ring,  and  are  frequently  found  in  the  scrotum ; — meconium  at  termination 
of  large  intestine ; — middle  point  of  body  at  umbilicus,  or  a  little  below  it. 

969.  From  the  time  of  its  entrance  into  the  world,  the  condition  of  the  Human 
Infant  is  essentially  changed.  It  is  no  longer  supplied  with  nutriment  by  the 
direct  transmission  of  organizable  materials  from  the  circulating  fluid  of  the 
mother  to  its  own ;  but  obtains  it  by  the  processes  of  digestion,  absorption,  and 
assimilation,  which  involve  the  establishment  of  new  modes  of  vital  activity  in  its 
own  organism.  Tn  order,  however,  that  the  change  may  not  be  too  sudden,  the 
nutriment  provided  by  Nature  for  the  early  period  of  infantile  life,  is  such  as  to 
occasion  the  least  possible  demand  upon  its  vital  powers,  for  the  preparation  of 
the  organizable  material  which  is  required  for  its  further  growth  and  develop- 
ment. But  the  transition  is  a  most  important  one  in  another  particular;  the 
infant  is  now  thrown  in  a  great  degree  upon  its  own  resources  for  the  generation 
of  its  Heat ;  and  this  it  is  enabled  to  accomplish  by  the  combustion  of  a  portion 
of  its  food  which  is  specially  provided  for  the  purpose;  this  combustion  being 
promoted  by  the  arrangement  for  that  active  Respiration,  which  now  supersedes 
the  very  limited  aeration  of  its  circulating  fluids  that  was  sufficient  during  foetal 
life.  In  the  movements  of  the  respiratory  muscles  and  of  the  walls  of  the  ali- 
mentary canal,  we  have  a  new  source  of  expenditure  of  vital  force,  and  of  destruc- 
tion of  tissue;  and  this  expenditure  is  progressively  augmented,  as  the  motions 
of  the  body  and  limbs  become  increasingly  active.  Thus  we  find  that  the  forma- 
tive powers  are  not  exercised  during  Infancy  and  Childhood,  solely  in  the  con- 
struction and  augmentation  of  the  fabric  (as  they  were  during  embryonic  life), 
since  there  is  a  constant  demand  upon  them  for  its  maintenance:  and  this 
demand  becomes  greater  and  greater,  in  proportion  to  the  activity  of  the  Animal 
powers.  These,  at  first  called  into  exercise  by  the  stimulus  of  sensory  impres- 
sions upon  the  Nervous  system  (§  591),  are  speedily  brought  into  very  energetic 
operation.  This  operation  is  of  an  extremely  limited  character,  being  at  first 
purely  sensorial,  and  for  some  time  afterwards  simply  perceptive  (§  603).  But 
the  whole  Mind  (such  as  it  is),  being  given-up  to  it,  habits  of  observation  are 
formed,  which  are  never  subsequently  lost;  the  infant  learns  how  to  use  his 
Organs  of  Sense;  and  he  also  acquires  those  powers  of  interpreting  their  indica- 
tions, which  become  so  completely  engrafted  into  his  nature,  as  henceforth  to 
seem  a  part  of  it.  Although  this  Education  of  the  Senses  will  necessarily  go- 
on, even  without  any  intentional  assistance  on  the  part  of  others,  yet  it  is  in  the 


INFANCY    AND     CHILDHOOD.  853 

power  of  the  Mother  or  Nurse  to  promote  it  effectually,  by  supplying  objects  of 
various  kinds  which  the  Infant  may  look-at  and  grasp,  and  by  not  abruptly  inter- 
fering (by  the  too-speedy  withdrawal  of  such  objects)  with  the  process  by  which 
the  visual  and  tactile  perceptions  are  blended  and  harmonized  (§758). — The1 
Nervous  system  of  the  Infant,  although  thus  called  into  extraordinarily-energetic 
activity,  cannot  long  sustain  that  activity;  a  very  large  measure  of  Sleep  is  re- 
quired for  the  restoration  of  its  speedily  exhausted  powers;  and  any  unusual  ex 
citement  of  them  tends  to  injurious  disturbances  of  its  nutrition.  It  is  owino1  tc 
this  peculiar  susceptibility  of  the  Nervous  system  of  the  Infant  to  external  in- 
fluences, that  medicines  (especially  narcotics)  which  exert  a  special  influence  upon 
that  system,  are  so  peculiarly  potent  in  their  effects  at  this  period  of  life,  that  the 
greatest  caution  is  needed  in  their  administration. 

970.  The  most  important  developmental  change  which  occurs  in  Infancy, 
after  the  complete  establishment  of  the  extra-uterine  circulation  (§  897),  is  the 
completion  and  eruption  of  the  first  set  of  Teeth ;  the  greater  part  of  whose  for- 
mation, however,  has  taken-place  before  birth.  These  'milk'  or  'deciduous' 
teeth,  20  in  number,  usually  make  their  appearance  in  the  following  order.  The 
four  central  Incisors  first  present  themselves,  usually  about  the  7th  month  after 
birth,  but  frequently  much  earlier  or  later;  those  of  the  lower  jaw  appear  first. 
The  lateral  Incisors  next  show  themselves,  those  of  the  lower  jaw  coming-through 
before  those  of  the  upper;  they  usually  make  their  appearance  between  the  7tb 
and  10th  months.  After  a  short  interval,  the  anterior  Molars  present  themselves, 
generally  soon  after  the  termination  of  the  12th  month ;  and  these  are  followed 
by  the  Canines,  which  usually  protrude  themselves  between  the  14th  and  20tb 
months.  The  posterior  Molars  are  the  last,  and  the  most  uncertain  in  regard  t« 
their  time  of  appearance ;  this  varying  from  the  18th  to  the  36th  month.  In 
regard  to  all  except  the  front  teeth,  there  is  no  settled  rule  as  to  the  priority  of 
appearance  of  those  in  the  upper  or  under  jaw;  sometimes  one  precedes,  and 
sometimes  the  other;  but  in  general  it  may  be  stated,  that  whenever  one  makes 
its  appearance,  the  other  cannot  be  far  off.  The  same  holds-good  in  regard  to 
the  two  sides,  in  which  development  does  not  always  proceed  exactly  pari  passu. 
—  The  period  of  Dentition  is  sometimes  one  of  considerable  risk  to  the  Infant's 
life ;  and  this  especially  when  an  irritable  state  of  the  nervous  system  has  been 
brought-about  by  unsuitable  food,  unwholesome  air,  or  some  other  cause  of  dis- 
ordered health.  In  such  cases,  the  pressure  upon  the  nerves  of  the  gum,  which 
necessarily  precedes  the  opening  of  the  sac  and  the  eruption  of  the  tooth,  is  a 
fruitful  source  of  irritation ;  producing  disturbance  of  the  whole  system,  and 
giving  origin  to  Convulsive  affections,  which  are  not  unfrequently  fatal.  These 
have  been  particularly  studied  by  Dr.  M.  Hall,  who  recommends  the  free  use  of 
the  gum-lancet,  as  a  most  important  means  of  prevention  and  cure;  but  the 
Author  has  no  doubt  that  too  much  attention  has  been  given  to  the  immediate 
source  of  the  irritation,  and  too  little,  to  the  general  state  of  the  system ;  and 
that  constitutional  treatment,  especially  change  of  air,  and  improvement  of  th< 
diet,  is  of  fundamental  importance.  In  infants  whose  general  health  is  good( 
and  who  are  not  over-fed,  Dentition  is  usually  a  source  of  but  very  trifling  dis- 
turbance ;  a  slight  febrile  action,  lasting  only  for  a  day  or  two,  being  all  that 
marks  the  passage  of  the  tooth  through  the  capsule ;  and  its  eruption  through 
the  gum  taking-place  without  the  least  indication  of  suffering  or  disorder.  Any 
existing  malady  or  abnormal  tendency,  however,  is  pretty  sure  to  be  aggravated 
during  the  '  cutting  of  the  teeth ;'  and  it  is  therefore  of  the  greatest  consequence, 
that  the  infant  should  be  withdrawn  during  this  period  from  all  injurious  in- 
fluences ;  and  that  no  irregularity  of  diet,  or  deficiency  of  fresh  air  and  exercise, 
should  operate  to  its  disadvantage. 

971.  Although  there  no  well-marked  divisions  between  the  periods  of  Child- 
hood,  Youth,  and  Adolescence,  through  all  of  which  we  witness  the  continuance 
of  the  processes  of  Growth  and  Development  (though  in  a  gradually-decreasing 


8^4  CHARACTERISTICS    OF    DIFFERENT    AGEP. 

ratio),  yet  we  may  appropriately  distinguish  each  as  the  epoch  of  one  of  those 
important  changes  which  tend  towards  the  completion  of  the  fabric;  namely, 
Childhood,  as  ranging  through  the  greater  part  of  the  period  of  the  second  Den- 
tition,—  Youth  as  characterized  by  that  increased  evolution  of  the  sexual  organs, 
and  by  those  general  constitutional  changes  accompanying  that  evolution,  which 
altogether  constitute  Puberty,  —  and  Adolescence  as  distinguished  by  that  entire 
consolidation  of  the  Osseous  skeleton,  which  is  not  completed  until  the  full 
stature  has  been  attained.  It  will  be  convenient  first  to  consider  what  is  common 
to  all  these  periods;  and  then  to  notice  the  features  by  which  they  are  severally 
characterized. 

972.  The  passage  from  Infancy  to  Childhood  may  be  regarded  as  marked  by 
the  eruption  of  the  '  deciduous '  Teeth ;  by  the  termination  of  that  direct  supply 
of  food  to  the  offspring,  which  is  afforded  until  then  by  the  Mammary  secretion 
of  the  mother ;  by  the  dawn  of  the  Intellectual  powers,  manifested  in  the  first 
efforts  at  speaking;  and  by  the  acquirement  of  sufficient  control  over  the  muscu- 
lar apparatus,  to  render  it  subservient  to  the  increasing  desire  which  then  dis- 
plays itself  for  independent  Locomotion.  All  these  advances  usually  take  place 
simultaneously,  or  nearly  so,  during  some  part  of  the  second  year;  some  Infants 
being  much  more  forward  than  others,  both  in  '  cutting  their  teeth '  and  in  learn- 
ing to  walk  and  to  talk.  When  they  have  been  completed,  the  Child  enters  upon 
a  life  which  is  in  many  respects  new.  The  alteration  of  its  diet  involves  a  much 
higher  activity  of  all  the  organs  which  are  concerned  in  making  blood ;  whilst 
its  greatly-increased  amount  of  exertion,  both  of  body  and  mind,  gives  occasion 
to  a  more  rapid  disintegration  of  the  nervous  and  muscular  tissues,  and  hence  to 
a  higher  activity  of  the  Excretory  organs.  This  will,  of  course,  progressively 
augment,  in  proportion  as  the  Nervo-muscular  apparatus  is  brought,  with  advanc- 
ing years,  into  more  vigorous  and  more  prolonged  exercise ;  until,  with  the  at- 
tainment of  adult  age,  the  disintegration  of  these  tissues  comes  to  be  the  chief 
source  of  the  Excrementitious  products.  But  during  the  whole  period  of  in- 
crease, there  is  another  source  of  demand  for  nutritive  activity,  in  that  perpetual 
re-construction  of  the  fabric  (involving  a  sort  of  continual  pulling-down  and  re- 
building on  a  larger  scale,  all  the  old  materials  being  carried-away  as  useless), 
which  is  a  necessary  condition  of  its  growth ;  but  this  demand  of  course  slackens 
with  the  diminution  of  the  rate  of  increase ;  and  at  last  it  ceases  altogether,  just 
when  the  other  attains  its  maximum.  Hence  the  demand  for  food,  on  the  one 
hand,  and  the  amount  of  excretory  matter  set-free  from  the  body,  on  the  other, 
are  remarkably  large  during  the  whole  of  this  period :  the  child,  as  every  one 
knows,  consuming  far  more  nutriment  than  the  adult,  in  proportion  to  the  weight 
of  their  respective  bodies;  and  the  like  being  true  of  the  quantity  of  carbonic 
acid  exhaled  from  the  lungs  (§  316  III),  and  of  the  urea  given-off  from  the  kid- 
neys (§  411). — That  the  germinal  capacity,  though  inferior  to  that  of  the  embryo, 
still  persists  in  a  high  degree  during  the  period  of  childhood  and  youth,  is  shown 
in  the  readiness  with  which  the  effects  of  injuries  and  disease  are  recovered  from; 
for  although  the  regeneration  of  lost  parts  does  not  take-place  to  nearly  the  same 
extent  as  during  early  embryonic  life,  yet,  up  to  a  certain  point,  it  is  effected 
with  great  completeness,  and  with  much  greater  rapidity  than  at  later  epochs. 
It  is  still,  in  fact,  rather  in  the  exercise  of  formative  power,  than  in  the  produc- 
tion of  nervo-muscular  vigour,  that  the  vital  force  of  the  earlier  part  of  this 
period  is  displayed ;  and  we  may  readily  trace  such  a  relation  of  reciprocity 
between  these  two  modes  of  its  manifestation,  as  is  strongly  indicative  of  the 
community  of  their  source.  For  it  is  familiar  to  every  observer,  that,  when  the 
growth  of  a  child  or  young  person  is  peculiarly  quick,  his  nervo-muscular  energy 
is  usually  feeble,  and  his  power  of  endurance  brief,  in  comparison  with  that 
which  can  be  put-forth  by  one  whose  frame  is  undergoing  less  rapid  increase. 
And  we  observe,  moreover,  that  the  capacity  of  resistance  to  depressing  influences 
of  various  kinds,  which  is  a  no  less  decided  manifestation  of  the  vital  power  of 


PSYCHICAL    CHARACTERS     OF    CHILDHOOD.  855 

the  organism  (/etiug  that  these  influences  are  of  a  kind  which  tend  towards  its 
death),  is  possessed  by  the  latter  in  a  far  higher  degree  than  by  the  former.  This 
is  remarkably  the  case  in  regard  to  privation  of  food  and  depression  of  external 
temperature;  under  which,  too,  children  and  young  persons  succumb  much  more 
speedily  than  adults. 

973.  It  is  most  interesting  to  trace,  during  the  progress  of  the  development 
of  the  bodily  fabric,  the  gradual  expansion  and  invigoration  of  the  Mental 
powers.  The  acquirement  of  Language,  as  already  remarked  (§  613),  constitutes 
the  most  important  step  in  the  development  of  the  ideational  consciousness ;  and 
it  is  easy  to  recognize  in  the  psychical  manifestations  of  Children,  the  further 
progress  of  that  development.  The  formation  of  Associations  between  ideas 
(§§  632 — 638)  takes-place  with  extraordinary  readiness  and  tenacity  during  the 
earliest  period  of  childhood;  and  these  exercise  so  much  influence  over  the  suc- 
cession of  the  thoughts  during  the  whole  remainder  of  life,  that  "  the  force  of 
early  associations "  has  become  proverbial.  Out  of  these  associations  arise,  on 
the  one  hand,  Memory  (§  642)  and  Imagination  (§  648);  on  the  other  hand, 
those  simple  processes  of  Reasoning  (§  646)  which  are  necessary  to  the  develop- 
ment of  a  higher  class  of  ideas.  Thus  the  mind  passes  from  those  primary 
notions  of  individual  objects  which  are  directly  suggested  by  sense-perceptions, 
to  those  abstract  ideas  of  their  qualities,  which  enable  them  to  recognize  those 
qualities  elsewhere,  notwithstanding  the  existence  of  differences  in  other  respects ; 
and  thence  to  those  general  ideas,  in  which  the  abstractions  are  embodied  (§  646). 
In  all  these  processes,  the  child-mind  seems  to  be  so  entirely  concentrated  upon 
the  particular  subject  of  its  thoughts,  as  to  be  '  possessed '  by  it  for  the  time, 
almost  as  completely  as  a  'biologized'  subject  is  by  his  dominant  idea  (§  672); 
and  no  prolonged  study  of  it  is  required  to  justify  the  statement,  that  its  opera- 
tions are  for  some  time  entirely  automatic,  and  that  the  acquirement  of  Volitional 
control  over  them,  on  the  part  of  the  individual,  is  a  very  gradual  process 
(§  677).  As  a  general  rule  it  may  be  laid-down,  that  the  activity  with  which 
the  formation  of  new  ideas  takes-place  in  the  child,  and  the  rapidity  with  which 
the  attention  transfers  itself  from  one  object  to  another,  prevents  any  single  state 
from  fixing  itself  durably  in  the  consciousness,  so  that  the  Memory  preserves  but 
faint  traces  of  the  greater  part  of  what  passes  through  the  mind ;  and  it  is  (for 
the  most  part)  only  when  the  same  thoughts  are  frequently  recurred-to,  that  they 
take  root  (so  to  speak)  in  the  psychical  nature.  Still  we  occasionally  find  that 
particular  impressions  exert  a  very  powerful  influence  on  the  subsequent  course 
of  thought  and  feeling ;  and  there  is  good  reason  to  believe,  that  even  where  the 
consciousness  loses  its  hold  over  them,  impressions  of  a  transient  nature  may 
leave  such  traces  in  the  Brain,  that  they  may  be  reproduced  at  any  future  time, 
when  the  appropriate  suggestion  may  happen  to  be  supplied  (§  642).  —  Whilst 
the  ideational  consciousness  is  thus  being  expanded  and  elevated,  the  Emotional 
part  of  the  Psychical  nature  is  rapidly  acquiring  a  greater  range  and  intensity  of 
action.  The  infant  and  young  child  give  ample  evidence  in  their  actions,  of  the 
several  forms  of  Emotional  Sensibility  which  connect  themselves  with  Sensational 
and  Perceptive  states  (§§  602,  607,  609);  but  no  sooner  does  the  development 
of  Ideas  commence,  than  the  various  modifications  of  *  feeling'  attach  themselves 
to  these  (§  619);  and  thus  almost  every  thought  that  is  not  a  purely-intellectual 
abstraction,  comes  to  possess  more  or  less  of  an  Emotional  character.  Here, 
again,  we  trace  the  powerful  influence  of  early  impressions;  for  notwithstanding 
that  the  state  of  feeling  which  is  habitual  to  each  individual,  may  depend  in  great 
decree  upon  his  original  constitution,  yet  it  is  unquestionable  that  it  is  largely 
influenced  (especially  in  its  association  with  particular  classes  of  ideas)  by  sym- 
pathy with  the  like  states  in  those  among  whom  the  child  receives  its  early  edu- 
cation (§  609).  It  is  of  peculiar  importance,  therefore,  that  this  example  should 
be  such  as  it  is  wholesome  for  the  child  to  imitate;  since  it  is  upon  the  habits 
of  feeling  thus  early  formed,  that  the  happiness  and  right  conduct  of  after-life 


856  CHARACTERISTICS     OF    DIFFERENT     AGES. 

mainly  depend.  This  statement  (winch  yet  applies  with  yet  greater  force  to  the 
Moral  Sense)  may  at  first  seem  inconsistent  with  the  well-known  fact,  that  the 
Emotions  of  children  are  peculiarly  transient  in  their  character,  even  when  they 
are  violently  excited  ;  one  state  of  feeling  giving-place  to  another,  even  of  the 
most  opposite  kind,  under  the  influence  of  some  new  impression,  or  of  some 
change  in  the  direction  of  the  ideas.  But  the  same  general  principle  applies  to 
this  case,  as  to  the  formation  of  habits  of  thought;  namely,  that  although  indi- 
vidual impressions  are  more  speedily  dissipated  from  the  minds  of  children  than 
from  those  of  adults,  yet  that  when  impressions  of  the  same  kind  are  frequently 
repeated,  the  brain  grows-to  them  in  such  a  manner,  that,  they  come  to  take-part 
(as  it  were)  in  its  ordinary  working;  and  thus,  by  establishing  a  particular  mode 
of  nutritive  assimilation,  they  tend  io  perpetuate  this  acquired  habit,  of  whatever 
nature  it  be. — The  right  training  of  the  Emotional  tendencies,  and  all  'he  higher 
uses  of  the  Intellectual  Faculties,  depend  in  great  degree,  as  already  shown 
(§  669),  upon  the  influence  of  the  Will  in  directing  the  current  of  thought  and 
feeling;  and  this  becomes  greater  and  greater,  if  rightly  cultivated,  with  the 
advance  of  years,  so  that  the  psychical  powers,  whilst  themselves  acquiring  an 
increase  of  vigour  and  comprehensiveness,  are  brought  more  and  more  under  the 
control  of  the  individual,  and  can  be  utilized  in  any  way  in  which  he  may  choose 
to  employ  them.  Thus  with  a  diminishing  molih'fy  of  thought  and  excitability 
of  feeling,  the  Mind  becomes  more  and  more  capable  of  tvgtQtned  and  defermi- 
nately -concentrated  activity;  and  is  at  the  same  time  progressively  acquiring  that 
store  of  familiar  experiences,  which  not  only  constitutes  the  basis  of  all  attain- 
ments in  special  departments  of  knowledge,  but  supplies  (when  judiciously  used) 
that  'common-sense'  by  which  we  form  most  of  our  judgments  and  direct  most 
of  our  conduct.  —  During  this  period,  moreover,  the  Muscular  apparatus  of 
Animal  life,  whose  actions  are  at  first  purely  automatic,  is  brought  more  and 
more  under  the  direction  of  the  Mind,  so  as  to  express  its  ideas,  its  feelings,  and 
its  volitions.  And  it  is  whilst  this  transference  is  going-on,  that  new  habits  of 
action  are  most  readily  formed,  and,  when  once  formed,  are  durably  impressed 
upon  the  organism  (§§  514,  550,  794). — The  excess  which  must  exist,  during 
the  whole  of  this  period,  in  the  constructive  over  the  destructive  activity,  and  the 
large  amount  of  the  latter  which  (as  already  shown)  arises  out  of  the  very  nature 
of  Growth,  in  addition  to  that  which  proceeds  from  the  increased  activity  of  the 
Animal  functions,  necessitates  a  much  larger  proportion  of  repose  than  suffices 
for  the  adult ;  but  this  necessity  diminishes  with  the  progress  of  years,  for  the 
reasons  already  mentioned ;  and  thus  we  find  that  whilst  the  young  child  passes 
16  or  18  hours  a  day  in  sleep,  half  that  time  suffices  for  the  youth  just  entering 
on  manhood. 

974.  The  Second  Dentition,  consisting  in  the  replacement  of  the  deciduous  or 
'  milk '  Teeth  by  the  permanent  Teeth  that  succeed  them,  which  is  the  most  im- 
portant developmental  change  that  occurs  during  the  period  of  Childhood,  nor- 
mally commences  in  the  7th  or  8th  year;  the  germs  of  the  new  teeth,  however, 
are  formed  long  previously,  having  their  origin  in  a  process  of  germination  from 
the  tooth-sacs  of  the  temporary  teeth,  which  takes-place  at  a  very  early  period  in 
the  development  of  the  latter.  The  three  permanent  Molars  on  either  side  of 
each  jaw,  however,  have  no  such  origin;  since  they  do  not  replace  temporary 
teeth.  The  first  pair,  which  usually  make  their  appearance  behind  the  temporary 
molars,  either  contemporaneously-with,  or  a  little  anteriorly-to,  the  first  shedding 
of  the  deciduous  teeth,  are  really  *  milk  '  teeth,  so  far  as  their  origin  is  concerned, 
since  they  are  developed  from  primitive  tooth-sacs  :  on  the  other  hand,  the  second 
true  molars,  which  afterwards  come-up  behind  them,  are  evolved  from  tooth-sacs 
which  hold  the  same  relation  to  those  of  the  first,  as  the  tooth  sacs  of  the  other 
permanent  teeth  do  to  those  of  the  deciduous  teeth  which  they  replace;  and  the 
third  true  molars,  or  denies  sapientias,  bear  the  like  relation  to  the  second.  Al- 
though the  eruption  of  the  true  molars  is  so  long  postponed,  yet  th*»  foundation 


SECOND   DENTITION:  —  TEST  OF  AGE.  857 

of  thorn  is  laid  at  an  early  period;  for  the  papilla  of  the  first  is  distinguishable 
at  the  16th  week  after  conception,  that  of  the   second  at  the  7th  month  after 


T2. 

Deciduous  and  Permanent  Teeth,  set. 

birth,  and  that  of  the  third  at  the  6th  year.  In  the  successive  replacement  of 
the  'milk'  teeth  by  the  'permanent'  set,  a  very  regular  order  is  usually  fol- 
lowed. The  middle  Incisors  are  first  shed  and  renewed,  and  then  the  lateral  In- 
cisors. The  anterior  '  milk  '  Molars  next  follow ;  and  these  are  replaced  by  the 
anterior  Bicuspid  teeth.  About  a  year  afterwards,  the  posterior  'milk'  Molars 
are  shed,  and  are  replaced  in  like  manner  by  Bicuspid  teeth.  The  Canines  are 
the  last  of  the  l  milk  '  teeth  to  be  exchanged ;  in  the  succeeding  year,  the  second 
pair  of  the  true  Molars  appears ;  but  the  third  pair,  or  dentes  sapientiae,  are 
seldom  developed  until  three  or  four  years  subsequently,  and  often  much  later. 

975.  It  has  been  proposed  '  (and,  from  the  evidence  adduced  in  its  favour,  the 
proposition  would  seem  entitled  to  considerable  attention)  to  adopt  the  successive 
stages  in  the  Second  Dentition,  as  standards  for  estimating  the  physical  capabili- 
ties of  Children,  especially  in  regard  to  those  two  periods  which  the  Factory-Laws 
render  it  of  the  greatest  importance  to  determine;  namely,  the  ages  of  nine  and 
thirteen  years.  Previously  to  the  former,  a  Child  is  not  permitted  to  work  at  all ; 
and  up  to  the  latter,  it  may  be  only  employed  during  nine  hours  a  day.  The 
necessities  or  the  cupidity  of  Parents  are  continually  inducing  them  to  misrepre- 
sent the  ages  of  their  children;  and  it  has  been  found  desirable,  therefore,  to  seek 
for  some  test,  by  which  the  capability  of  the  Child  may  be  determined,  without  a 
knowledge  of  its  ago.  A  standard  of  Height  has  been  adopted  by  the  Legislature 
for  this  purpose;  but  upon  grounds  which,  physiologically  considered,  are  very 
erroneous;  since,  as  is  well  known,  the  tallest  children  are  frequently  the  weak- 
liest (§  972).  According  to  Mr.  Saunders,  the  degree  of  advance  of  the  Second 
Dentition  may  be  regarded  as  a  much  more  correct  standard  of  the  degree  of 
general  development  of  the  organic  frame,  and  of  its  physical  powers ;  and  it 
appears  from  his  inquiries,  that  it  may  be  relied-on  as  a  guide  to  the  real  age,  in 
a  large  proportion  of  cases;  whilst  no  serious  or  injurious  mistake  can  ever  arise 

1  "The  Teeth  a  Test  of  Age,  considered  with  reference  to  the  Factory  Children."  By 
Edwin  Saunders. 


858  CHARACTERISTICS    OF     DIFFERENT    AGES. 

from  its  use.  It  may  happen  that  local  or  constitutional  causes  may  have  slightly 
retarded  the  development  of  the  Teeth  ;  in  which  case  the  age  of  the  individual 
would  rather  be  under-estimated,  and  no  harm  could  ensue  :  on  the  other  hand, 
instances  of  premature  development  of  the  Teeth  very  rarely,  if  ever,  occur ;  so 
that  there  is  little  danger  of  imputing  to  a  Child  a  capability  for  exertion  which 
he  does  not  possess,  as  the  test  of  height  is  continually  doing.  Moreover,  if  such 
an  advance  in  Dentition  should  occur,  it  might  probably  be  regarded  as  indicative 
of  a  corresponding  advance  in  the  development  of  the  whole  organism  ;N  so  that 
the  real  capability  would  be  such  as  the  teeth  represent  it. — The  following  is 
Mr.  Saunders' s  statement  of  the  Ages,  at  which  the  <  permanent'  Teeth  respec- 
tively appear.  The  first  true  Molars  usually  present  themselves  towards  the  end 
of  the  7th  year.  Occasionally  one  of  them  protrudes  from  the  gum  at  6,  or  more 
frequently  at  6£  years  of  age;  but  the  evolution  of  the  whole  of  them  may  be 
regarded  as  an  almost  infallible  sign  of  the  Child's  being  7  years  old.  In  other 
instances,  where  the  tooth  on  one  side  of  the  mouth  is  freely  developed,  it  is  fair 
to  reckon  the  two  as  having  emerged  from  their  capsule ;  since  the  development 
of  the  other  must  be  considered  as  retarded.  This  rule  only  holds  good,  how- 
ever, in  regard  to  teeth  in  the  same  row ;  for  the  development  of  the  teeth  in 
either  jaw  must  not  be  inferred  from  that  of  the  corresponding  teeth  in  the  other. 
With  this  understanding,  the  following  table  will  probably  be  very  near  the 
truth : — 

Central  Incisors  developed  at 8  years. 

Lateral  Incisors 9*    „ 

First  Bicuspid 10     „ 

Second  Bicuspid 11      „ 

Canines 12     to  12J 

Second  Molars 12J  to  14 

The  following  are  the  results  of  the  application  of  this  test,  in  a  large  number 
of  cases  examined  by  Mr.  Saunders.  Of  708  children  of  nine  years  old,  530 
would  have  been  pronounced  by  it  to  be  near  the  completion  of  their  ram/^year; 
having  the  central,  and  either  three  or  four  lateral,  incisors  fully  developed.  Out 
of  the  remaining  178,  it  would  have  indicated  that  126  were  8£  years  old,  as 
they  presented  one  or  two  of  the  lateral  Incisors ;  and  the  52  others  would  have 
been  pronounced  8  years  old,  all  having  three  or  four  of  the  central  Incisors.  So 
that  the  extreme  deviation  is  only  12  months ;  and  this  in  the  inconsiderable  pro- 
portion  (when  compared  with  the  results  obtained  by  other  means)  of  52  in  708, 
or  7i  per  cent.  Again,  out  of  338  children  of  13  years  of  age,  294  might  have 
been  pronounced  with  confidence  to  be  of  that  age;  having  the  Canines,  Bicus- 
pid, and  second  Molars,  either  entirely  developed,  or  with  only  the  deficiency  of 
one  or  two  of  either  class.  Of  the  44  others,  36  would  have  been  considered  as 
in  their  13th  year,  having  one  of  the  posterior  Molars  developed;  and  8  as  near 
the  completion  of  the  12th,  having  two  of  the  Canines,  and  one  or  two  of  the 
second  Bicuspid.  In  all  these  instances,  the  error  is  on  the  favourable  side, — 
that  is,  on  the  side  on  which  it  is  calculated  to  prevent  injury  to  the  objects  of 
the  inquiry ;  in  no  instance  did  this  test  cause  a  Child  to  be  estimated  as  older 
or  more  fit  for  labour  than  it  really  was.1 

1  The  value  of  this  test,  as  compared  with  that  of  Height,  is  manifested  by  a  striking 
example  adduced  by  Mr.  Saunders.  The  height  of  one  lad,  J.  J.,  aged  8  years  and  4 
months,  was  4  feet  and  f  of  an  inch  ;  that  of  another  boy,  aged  8  years  and  7  months,  was 
only  3  feet  7^  inches.  According  to  the  standard  of  height  adopted  by  the  Factory  Com- 
missioners (namely  3  feet  10  inches),  the  taller  lad  would  have  been  judged  fit  for  labour, 
whilst  the  shorter  would  have  been  rejected.  The  Dentition  of  the 'latter,  however,  was 
further  advanced  than  that  of  the  former;  for  he  had  two  of  the  lateral  Incisors,  whilst 
the  former  had  only  the  central :  and  the  determination  of  their  relative  physical  powers, 
which  would  have  been  thus  formed,  would  have  been  in  complete  accordance  with  the 
truth.  The  elder  boy,  though  shorter  than  the  other  by  5£  inches,  possessed  a  much 
greater  degree,  both  of  corporeal  and  mental  energy,  and  his  pulse  was  strong  and  regular ; 
whilst  that  of  the  younger  lad,  who  was  evidently  growing  too  fast,  was  small  and  fre- 
quent.— An  instance  even  more  striking  has  come  under  the  Author's  own  observation. 


PUBERTY: — ADOLESCENCE;  COMPLETION  OF  OSSIFICATION.       859 

976.  The  period  of  Youth  is  distinguished  by  that  advance  in  the  evolution  of 
the  Generative  apparatus  in  both  sexes,  and  by  that  acquirement  of  its  power  of 
functional  activity,  which  constitutes  the   state  of  Puberty.     Of  the   principal 
changes  in  which  this  consists,  in  the  two  sexes  respectively,  an  account  has 
already  been  given  (§§  846,  852,  915);  and  it  is  merely  requisite  here  to  add, 
that  this  augmented  development  can  only  be  rightly  regarded  as  preparatory  to 
the  exercise  of  these  organs,  and  not  as  showing  that  the  aptitude  for  their  exer- 
cise has  already  been  fully  attained.     It  is  only  when  the  growth  and  development 
of  the  individual  are  completed,  that  the  procreative  power  can  be  properly  ex- 
erted for  the  continuance  of  the  race  ;  and  all  experience  shows,  that  by  prema- 
turely and  unrestrainedly  yielding  to  the  sexual  instincts,  not  merely  the  genera- 
tive power  is  early  exhausted,  but  the  vital  powers  of  the  organism  generally  are 
reduced  and  permanently  enfeebled ;  so  that  any  latent  predisposition  to  disease 
is  extremely  liable  to  manifest  itself;  or  the  bodily  vigour,  if  for  a  time  retained 
with  little  deterioration,  early  undergoes  a  marked  diminution. 

977.  After  the  attainment  of  Puberty,  no  marked  alteration  takes-place  in  the 
organism,  save  the  continuance  of  its  increase  in  stature,  usually  for  a  few  years 
longer  (§  914);  which  increase  is  the  chief  manifestation  of  the  excess  of  the 
germinal  capacity,  that  has  not  yet  expended  itself  in  the  building-up  of  the 
fabric.     But  so  long  as  this  increase  is  going-on,  there  is  a  want  of  that  solidity 
and  compactness  of  the  organism,  which  seem  only  attainable  when  growth  has 
ceased  ;  and  the  attainment  of  which,  being  essential  to  the  highest  manifesta- 
tions of  vigour  and  endurance,  marks  the  final  completion  of  its  development. 
Of  this  we  have  the  best  illustration  in  the  Osseous  system ;  whose  completion, 
being  postponed  until  all  further  growth  has  ceased,  may  be  fairly  considered  as 
marking  the  final  stage  in  the   development  of  the  organism,  and  as  therefore 
characterizing  the  period  of  Adolescence. — Commencing  with  the  Vertebral  Co- 
lumn, we  find  that  whilst  the  'body'  and  '  neural  arches'  of  each  vertebra  be- 
come consolidated  in  early  childhood,  the  spinous  and  transverse  processes  are 
completed  by  separate  '  epiphyses/  the  ossification  of  which  does  not  commence 
until  after  puberty,  and  the  final  union  of  which  with  the  body  of  the  bone  may 
not  occur  until   the  age  of  twenty-five  or  thirty  years.     About  the  same  time, 
there  is  formed  and  added  to  each  surface  of  the  body  of  the  vertebra,  a  smooth 
annular  plate  of  solid-  bone,  which  covers  a  portion  that  was  previously  rough  and 
fissured.     During  this  period,  the  consolidation  of  the  Sacrum  is  proceeding; 
the  component  vertebrae  of  which  remain  separate  up  to  about  the  sixteenth  year, 
and  then  begin  to  unite  from  below  upwards,  the  union  of  the  two  highest  being 
completed   by  about  the  twenty-fifth  or  the  thirtieth  year;  whilst  at  the  same 
time,  thin  osseous  plates  are  formed  on  either  side  of  the  coalesced  mass,  which 
seem  to  represent  the  epiphyses  of  the  transverse  processes  of  its  component 
vertebras,  and  like  them  are  finally  joined-on  to  the  body  of  the   bone.     The 
ossification  and  coalescence  of  the  Coccygeal  vertebrae  takes-place  at  a  still  later 
period.     Each  Rib  in  like  manner,  has  two  epiphyses,  one  for  the  head  and  the 
other  for  the  tubercle  ;  the  ossification  of  which  begins  soon  after  puberty,  whilst 
their  union  with  the  body  of  the  bone  is  not  completed  until  some  years  after- 
wards.    The  five  pieces  of  which  the  Sternum  consists,  though  themselves  com- 
pletely ossified,  remain  separate  until  after  the  age  of  puberty;  when  their  union 
commences  from  below  upwards,  as  in  the  sacrum,  not  being  always  completed, 
however,  even  in  old  age,  by  the  junction  of  the  first  piece  to  the  rest  of  the 
bone.     The  ossification  of  the  Ensiform  cartilage  does  not  commonly  begin  until 
after  the  age  of  puberty;  and  it  is  usually  not  entirely  completed,  even  in  very 
advanced  life. — The  ossific  union  of  the  separate  elements  of  the  Bones  of  the 
Skull  (§  908)  is  usually  completed  within  a  few  years  after  birth;  but  there  are 
some  parts,  which  not  unfrequently  remain  distinct  during  the  greater  portion  of 
life,  and  which  may  even  never  coalesce;  such  is  the  case  with  the  two  halves 
of  the  Frontal  bone,  which  often  remain  permanently  divided  by  a  continuation 


860  CHARACTERISTICS    OF    DIFFERENT    AGES. 

of  the  sagittal  suture,  and  with  the  Styloid  process  of  the  temporal  bone.  In 
the  Upper  Extremities,  we  find  the  Scapula  presenting  three  epiphyses,  one  for 
the  coracoid  process,  one  for  the  acromiou,  and  one  for  the  lower  angle  of  the 
bone  ;  the  ossification  of  which  begins  soon  after  puberty,  their  union  with  the 
body  of  the  bone  taking-place  between  the  ages  of  twenty-two  and  twenty-five 
years.  The  Clavicle  has  an  epiphysis  at  its  sternal  end,  which  begins  to  form 
between  the  eighteenth  and  twentieth  years,  and  is  united  to  the  rest  of  the  bone 
a  few  years  later.  The  consolidation  of  the  Humerus  is  completed  rather  earlier ; 
the  large  piece  at  the  upper  end,  which  is  formed  by  the  coalescence  of  the  ossific 
centres  of  the  head  and  two  tuberosities,  unites  with  the  shaft  at  about  the 
twentieth  year;  whilst  it  lower  extremity  is  completed,  by  the  junction  of  the 
external  condyle  and  of  the  two  parts  of  the  articulating  surface  (previously  united 
with  each  other),  at  about  the  seventeenth  year,  and  by  that  of  the  internal  con- 
dyle in  the  year  following.  The  superior  epiphyses  of  the  Radius  and  Ulna 
unite  with  their  respective  shafts  at  about  the  age  of  puberty ;  the  inferior,  which 
are 'of  larger  size,  at  about  the  twentieth  year.  The  epiphyses  of  the  Metacarpal 
and  Phalangeal  bones  are  united  to  their  principals  at  about  the  twentieth  year. 
— In  the  Lower  Extremities,  the  process  of  ossification  is  completed  at  nearly 
the  same  periods  as  that  of  the  corresponding  parts  of  the  upper.  The  consoli- 
dation of  the  Ilium,  Ischium,  and  Pubis,  to  form,  the  Os  Innominatum,  by  the 
ossification  of  the  triradiate  cartilage  that  intervenes  between  them  in  the  aceta- 
bulum,  does  not  take-place  until  after  the  period  of  puberty;  and  at  this  time, 
additional  epiphyses  begin  to  make  their  appearance  on  the  crest  of  the  ilium,  on 
its  anterior  inferior  spine,  on  the  tuberosity  of  the  ischiurn,  and  on  the  inner 
margin  of  the  pubes,  which  are  not  finally  joined  to  the  bone  until  about  the 
twenty -fifth  year. 

978.  The  rapid  increase  in  Viability  which  shows  itself  in  both  sexes  up  to 
the  age  of  puberty,  its  rapid  decline  from  that  point,  and  its  subsequent  increase 
in  the  male  up  to  the  age  of  thirty,  have  been  already  pointed-out  (§  913).  The 
disorders  to  which  the  organism  is  most  subject,  during  the  several  periods  which 
have  now  been  considered,  are  by  no  means  the  same  for  each.  In  early  Child- 
hood, when  there  is  a  great  demand  for  the  activity  of  the  Digestive  and  Assimi- 
lative functions,  and  these  have  to  be  exercised  upon  nutriment  to  which  their 
organs  are  not  yet  accustomed,  we  find  derangements  of  those  organs  to  be  among 
the  most  common  of  all  maladies ;  these  may  be  serious  enough  in  themselves 
to  constitute  dangerous  and  even  rapidly-fatal  diseases ;  but  even  when  they  do 
not  take  these  acute  forms,  a  foundation  is  often  laid,  in  habits  of  perverted  Nu- 
trition thence  arising,  for  disorders  of  a  more  chronic  nature  (especially  those 
depending  on  the  Tubercular  diathesis,  §  376),  which  may  not  manifest  them- 
selves for  many  years  afterwards.  The  peculiar  activity  of  the  nervous  centres, 
which  is  prolonged  from  Infancy  into  early  Childhood,  involves  a  continued  lia- 
bility to  derangements  of  their  nutrition  or  of  their  functions ;  and  thus  it  hap- 
pens that  in  young  children  of  scrofulous  temperament,  it  is  either  in  the 
mesenteric  glands,  or  in  the  brain  or  its  membranes,  that  tubercular  deposit  first 
takes-place.  The  second  Dentition,  like  the  first,  is  often  accompanied  with  a 
great  deal  of  constitutional  disturbance;  especially  in  such  individuals  as  are 
suffering  from  defective  Nutrition,  or  from  an  irritable  state  of  the  Nervous 
System.  In  the  former  case,  there  is  a  special  proneness  to  Tubercular  disease ;  ' 
in  the  latter,  to  Epilepsy,  Chorea,  or  some  other  form  of  disorder  of  the  nervous 
centres,  the  connection  of  which  with  Dentition  is  shown  by  its  abatement  when 
that  epoch  has  passed.  A  large  part  of  the  sickness  and  mortality,  however, 
which  presents  so  high  a  rate  during  the  whole  period  of  Childhood,  is  due  to 

1  It  is  a  very  significant  circumstance,  that  of  the  many  specimens  of  the  Anthropoid 
Apes  which  have  been  brought  alive  to  this  country,  not  one  has  survived  its  second  denti- 
Hon ;  and  that,  in  almost  every  case,  it  has  been  by  tubercular  disease  that  their  lives 
have  been  thus  prematurely  cut-off. 


DISEASES    OF   PERIOD    OF   GROWTH. — MATURITY.     861 

various  forms  of  Zymotic  disease,  especially  the  Exanthemata  and  Infantile  Re- 
mittent Fever,  and  to  their  sequelae. — The  attainment  of  Puberty  in  the  Male 
sex  is  not  usually  attended  with  any  specific  tendency  to  disease;  nor  would  it 
probably  be  in  the  Female,  if  her  mode  of  life  were  more  accordant  with  the 
rules  of  health.  Although  disorder  of  the  Menstrual  function  is  one  of  the  most 
common  phenomena  of  female  youth,  yet  it  is  undoubtedly  to  be  looked-upon 
more  frequently  as  a  symptom  of  general  defect  of  nutrition  (and  especially  of 
an  impoverished  condition  of  the  blood),  than  as  itself  constituting  a  disease. 
The  extraordinary  reduction  in  the  probability  of  life,  indicating  a  large  mor- 
tality, during  the  years  which  immediately  succeed  puberty,  seems  to  depend  in 
great  degree,  in  the  Male,  upon  the  premature  use  of  his  generative  powers,  and 
upon  his  entrance  upon  the  active  employments  of  life  before  his  constitution 
has  received  that  invigoration  which  results  from  the  completion  of  his  bodily 
development;  whilst  in  the  Female,  it  is  very  commonly  attributable  to  the 
accumulation  of  unhealthy  influences,  which  began  to  '  tell '  upon  the  powers  of 
her  system,  when  its  germinal  capacity  no  longer  ministers  to  its  active  regenera- 
tion. It  is  then,  in  both  sexes,  though  from  causes  whose  immediate  nature  is 
different,  that  the  Tuberculous  diathesis  is  prone  to  develop  itself  with  peculiar 
intensity,  and  that,  by  fixing  npon  the  Respiratory  organs,  it  produces  the  most 
rapidly-fatal  alterations  in  structures  whose  integrity  is  essential  to  life. 

979.  Period  of  Maturity. — The  cessation  of  growth,  and  the  completion  of 
the  developmental  processes,  which  indicate  the  attainment  of  Manhood,  are 
accompanied  by  a  marked  increase  in  the  general  vigour  of  the  organism,  and  by 
a  special  augmentation  in  the  power  of  endurance  in  the  exercise  of  the  Animal 
faculties.  With  the  exception  of  those  parts  of  the  fabric  whose  utility  was 
confined  to  the  earlier  periods  of  its  development,  we  find  every  organ  now  pre- 
senting its  greatest  capacity  for  sustained  activity ;  and  thus  it  is  from  the  cha- 
racters which  each  presents  at  this  period,  that  we  base  our  ideas  of  its  typical 
perfection  of  structure  and  composition.  All  the  previous  changes  which  the 
organism  has  undergone,  both  as  a  whole,  and  in  its  separate  parts,  concur  to  the 
attainment  of  this  perfection,  as  we  have  especially  seen  in  regard  to  the  evolu- 
tion of  the  solid  framework  of  the  body;  and  every  subsequent  change,  as  we 
shall  presently  perceive  (§  981),  involves  a  deterioration  from  it.  The  whole 
nisus  of  development,  during  this  period,  appears  to  be  directed  towards  the 
maintenance  of  the  organism  in  the  state  which  it  had  acquired  at  its  commence- 
ment; by  the  regeneration  of  its  tissues  as  fast  as  they  undergo  disintegration, 
and  by  the  renovation  of  its  vital  force  in  proportion  as  this  is  expended.  There 
is  no  longer  any  capacity  for  the  production  of  new  organs,  and  comparatively 
little  for  the  augmentation  of  those  already  existing ;  the  increase  of  the  Uterine 
and  Mammary  structures,  during  the  period  of  gestation,  being  the  most  im- 
portant examples  of  formative  power,  and  these  presenting  themselves  in  the  sex 
in  which  there  is  least  of  nervo-muscular  activity  and  of  general  vigour.  We 
should  infer  then,  that  the  'germinal  capacity'  is  now  on  the  decline;  and  this 
further  appears  from  the  diminished  energy  and  completeness  with  which  the 
reparative  processes  are  performed,  as  compared  with  the  mode  in  which  they 
are  executed  during  the  period  of  growth.  There  is  consequently  a  less  demand 
for  alimentary  material  (allowance  being  made  for  the  augmented  bulk  of  the 
body)  than  during  the  previous  periods;  and  the  dependence  of  life  upon  a  con- 
stant supply  of  aliment  is  far  less  close.  Moreover,  the  ordinary  rate  of  waste 
or  degeneration  of  tissue  is  now  much  less  rapid  than  during  the  period  of  growth; 
for  we  have  seen  that  decay  and  removal,  in  the  latter  case,  are  among  the  very 
conditions  of  increase ;  whilst  in  the  former,  they  proceed,  for  the  most  part, 
only  from  the  expenditure  of  the  vital  powers  of  the  tissues,  consequent  upon 
their  functional  activity.  Hence  it  is  upon  the  degree  in  which  the  Anivial 
powers  are  exercised,  that  the  demand  for  food  chiefly  depends  in  the  Adult;  the 
sole  purpose  of  the  Organic  or  Vegetative  operations  being  (so  to  speak)  to  keep 


862  CHARACTERISTICS    OF    DIFFERENT    AGES. 

the  apparatus  of  Animal  life,  now  fully  developed,  in  working-order.  The  relative 
activity  of  the  different  parts  of  this  apparatus  is  now  somewhat  modified.  The 
observing  faculties  no  longer  possess  the  same  pre-eminence  ;  the  emotional  sensi- 
bility is  less  readily  excited  ;  but  the  intellectual  powers  now  act,  in  the  modes 
which  have  become  habitual  to  them,  with  a  sustained  vigour  and  completeness 
which  they  never  previously  possessed.  And  so,  whilst  the  muscles  are  not  so 
easily  excited  to  contraction,  and  new  combinations  of  movement  are  acquired 
with  far  more  difficulty  than  during  the  period  of  growth  and  development,  the 
force  which  they  can  generate  by  their  contraction  is  augmented,  and  this  force 
can  be  kept-up  for  a  much  longer  time  in  adults  than  in  younger  subjects. 

980.  The  duration  of  the  period  over  which  this  'maintenance7  may  be  pro- 
tracted, without  any  sensible  deterioration,  depends  in  great  degree  upon  the  due 
observance  of  all  the  conditions  of  health.     If  the  various  mental  and  bodily 
faculties  are  duly  exercised,  without  being  overtasked, — if  an  amount  of  Sleep 
adequate  to  their  periodic  renovation  be  regularly  taken, — if  a  sufficient  but  not 
excessive  quantity  of  wholesome  food  be  ingested  at  appropriate  intervals, — if 
the  functions  by  which  the  blood  is  prepared,  and  those  by  which  it  is  kept  in 
purity,  be  duly  performed, — if  all  such  noxious  agents  as  foul  air,  alcoholic 
liquors,  tobacco-smoke,  be  kept  at  a  distance, — and  there  be  no  constitutional 
predisposition  to  disease  on  the  one  hand,  nor  any  exposure  to  extraneous  mor- 
bific causes,  on  the  other, — it  may  be  fairly  anticipated  that  the  bodily  and  men- 
tal vigour  may  be  sustained  with  little  deterioration  during  a  long  succession  of 
years.     The  circumstances  that  most  tend  to  premature  decline,  are,  on  the  one 
hand,  excessive  exertion  either  of  the  mental  faculties  or  of  the  generative  power; 
or,  on  the  other,  undue  indulgence  in  food,  or  in  stimulating  drinks,  or  in  any 
practice  that  tends  to  disorder  the  Organic  functions,  especially  by  exciting  them 
to  undue  activity.     Every  one  who,  in  any  of  these  modes,  may  "  live  too  fast/' 
is  almost  certain  to  pay  the  penalty,  in  an  abbreviation  of  his  term  of  vigorous 
activity;  which  may  be  either  brought  to  a  sudden  and  final  close  by  fatal  disease, 
or  may  be  prematurely  reduced  by  more  gradual  decay.     And  this  tendency  will 
of  course  be  more  decided,  the  greater  is  the  amount,  and  the  larger  the  combi- 
nation, of  those  departures  from  the  Laws  of  Health  which  give-rise  to  it. 

981.  Period  of  Decline. — The  decline  of  life  exhibits  a  much  more  obvious 
diminution  of  the  whole  vital  power  of  the  organism ;  for  not  only  is  its  formative 
activity  now  greatly  reduced,  but  its  nervo-muscular  energy  and  general  vigour 
progressively  diminish,  and  its  generative  power  becomes  enfeebled,  or  ceases 
entirely  (§§  846,  854).     Of  this  diminution  in  formative  power,  we  have  evidence 
in  the  entire  absence  of  any  attempt  at  new  development,  in  the  less  perfect  and 
more  tedious  manner  in  which  the  losses  of  substance  occasioned  by  disease  or 
injury  are  recovered-from,  and  in  the  gradual  deterioration  of  the  organism  in 
general.     The  tissues  which  are  rendered  effete  by  their  functional  activity,  are 
not  any  longer  replaced  in  their  normal  completeness ;  for  either  the  quantity  of 
new  tissue  is  inadequate,  so  that  the  bulk  of  the  organs  is  obviously  reduced;  or 
their  quality  is  rendered  imperfect,  by  the  production  of  structures  in  various 
phases  of  degeneration,  in  place  of  those  which  had  been  previously  developed  in 

^the  fullest  completeness.  The  inferiority  of  Nervo-muscular  energy  and  of  gene- 
ral vigour  are  thus  evidently  the  result  of  the  deficiency,  and  not  (as  in  the  pe- 
riod of  growth)  of  the  excess  of  formative  power;  and  in  proportion  as  the 
1  waste '  of  the  tissues,  consequent  upon  their  functional  activity,  is  more  rapid 
than  their  renovation,  a  progressive  loss  of  substance  must  take-place.  The  forms 
of  Degeneration  most  commonly  met-with  in  advanced  age,  are  the  fatty  and  the 
calcareous.  The  former  (§  349)  is  extremely  prone  to  show  itself  in  those  organs 
whose  integrity  of  structure  is  peculiarly  important  to  health,  and  whose  deterio- 
ration interferes  directly  with  the  vital  properties  of  their  component  tissues. 
Thus  we  observe  it  in  the  Muscular  apparatus  generally,  but  pre-eminently  in  the 
walls  of  the  Heart;  and  in  proportion  as  its  contractile  fibre  has  been  replaced  by 


PERIOD    OF    DECLINE.  803 

particles  of  fat,  must  the  vital  energy  of  any  muscle  be  lowered.  !So,  again,  we 
tiud  the  same  degeneration  in  the  Liver,  Kidney,  and  other  parts  of  the  Glandu- 
lar apparatus ;  the  proper  secreting  action  of  which  is  impaired  in  the  ratio  of  the 
substitution  of  fat  for  the  proper  Glandular  elements.  But  it  may  also  lead  to 
most  serious  derangements  of  the  vital  functions,  by  its  interference  with  the 
purely-mechanical  actions  of  certain  parts  of  the  organism ;  thus,  fatty  degenera- 
tion of  the  walls  of  the  Blood-vessels  is  one  of  the  most  frequent  causes  of  those 
extravasations  of  blood  in  the  nervous  centres,  which  give  rise  to  the  apoplexy 
and  to  the  various  forms  of  paralysis  so  common  among  the  aged ;  and  the  same 
change  occurring  in  the  Bones,  gives  them  that  peculiar  brittleness  which  they 
frequently  exhibit  in  advanced  periods  of  life-  That  general  decline  of  the  vital 
powers,  which  has  received  the  name  of  *  climacteric  disease/  appears  traceable 
to  the  same  source.1 — The  tendency  of  the  calcareous  degeneration  (which  espe- 
cially affects  the  Cartilaginous  and  Fibrous  tissues)  is  almost  exclusively  to  inter- 
fere with  the  mechanical  adaptations  of  the  organism;  producing  an  injurious 
rigidity  in  various  structures,  which  require  a  greater  or  less  amount  of  flexibility 
for  the  normal  performance  of  their  functions.  Thus  it  is  very  common  for  the 
cartilages  of  the  ribs  to  become  ossified  in  advanced  life,  so  as  to  interfere  with 
the  free  movement  of  the  walls  of  the  thorax;  and  the  thyroid  cartilages  of  old 
people  are  frequently  converted  into  bone,  producing  a  roughness  of  the  voice,  and 
deficiency  of  the  power  of  modulating  it.  The  intervertebral  substance  (which  is 
partly  cartilaginous  and  partly  fibrous)  not  unfrequently  becomes  solidified  in  the 
lumbar  region,  as  do  also  the  spinal  ligaments,  so  that  several  of  the  lower  verte- 
brae are  firmly  anchylosed  to  each  other  and  to  the  sacrum ;  and  a  like  change 
often  takes-place  in  the  pelvic  articulations,  so  that  the  pelvis  and  the  lower  part 
of  the  spine  become  one  continuous  mass  of  bone,  destitute  of  flexibility  or  yield- 
ingness  in  any  part.  In  like  manner,  the  cranial  sutures  often  become  obliterated, 
and  calcareous  deposits  occur  in  the  duplicatures  of  the  dura  mater  forming  the 
falx  and  tentorium.  A  large  amount  of  this  kind  of  change  may  take-place,  with- 
out, any  serious  interference  with  the  Organic  functions,  although  it  tends  to  cur- 
tail the  Animal  powers.  When  the  calcareous  degeneration,  however,  extends 
itself  to  the  vital  organs,  the  interruption  which  it  occasions  in  their  actions  may 
be  fatal ;  thus,  next  to  fatty  degeneration,  there  is  probably  no  more  frequent 
cause  of  failure  of  the  heart's  action,  or  of  extravasation  from  the  blood-vessels, 
in  old  persons,  than  ossification  of  the  valvular  apparatus  of  the  former,  depriving 
it  of  the  flexibility  which  is  essential  to  its  proper  action,  or  of  the  fibrous  walls 
of  the  latter,  imparting  to  them  a  brittleness  which  predisposes  to  rupture. 

982.  Thus,  then,  with  the  advance  of  Old  Age,  the  organism  becomes  progres- 
sively more  and  more  unfit  for  the  active  performance  of  its  vital  operations;  a 
gradual  weakening  is  observable  in  the  Mental  as  well  as  in  the  Corporeal  energy ; 
and  a  retardation  becomes  obvious  in  the  current  of  Organic  life.  The  mind  is 
far  less  active  than  in  the  periods  of  Maturity ;  the  perceptions  are  dull,  the  feel- 
ings comparatively  obtuse  (save  where  some  dominant  emotion  has  gained  pos- 
session, through  the  previous  habit  of  yielding  to  it),  the  intellectual  powers  can- 
not be  so  readily  put  in  action,  and  the  imagination  loses  its  vividness.  There 
are  few  instances  in  which  any  great  works,  either  literary  or  artistic,  have  been 
executed  afrer  the  age  of  threescore.  Still,  the  experience  of  a  long  life  gives 
value  to  the  judgment;  and  the  counsels  of  the  old,  where  the  bearings  of  the 
quesfion  can  be  fully  understood,  deserve  the  respect  of  the  young,  more  espe- 
cially in  cases  where  temporary  ardour  of  feeling  tends  in  the  latter  to  supersede 
the  dictates  of  their  calmer  reason. — The  mental  torpor  is  correlated,  there  seems 
no  reason  to  doubt,  with  changes  in  the  condition  of  the  Nervous  substance, 
which  impair  its  original  activity ;  and  like  changes,  occurring  in  the  Muscular 
substance,  diminish  its  capacity  for  physical  exertion.  Hence  there  is,  on  the 

1  See  Mr.  Barlow's  '  General  Observations  on  Fatty  Degeneration,'  in  the  "  Medical 
limes  and  Gazette,"  May  15,  1852. 


864  OF    DEATH. 

one  hand,  a  marked  diminution  in  the  demand  for  food  ;  on  the  other,  a  like  dimi- 
nution in  the  rate  of  the  excretory  processes,  as  is  seen  especially  in  the  exhala- 
tion of  carbonic  acid  (§  316  ill.)  and  in  the  excretion  of  Urea  (§  411)  :  and  in 
accordance  with  all  these  reductions,  there  is  a  greatly-diminished  power  of  sus- 
taining the  heat  of  the  body,  the  temperature  of  which  consequently  becomes 
liable  to  a  serious  depression  from  external  cold.1  This  retardation  of  vital  acti- 
vity gradually  becomes  more  and  more  marked,  until,  if  neither  accident  nor  dis- 
ease should  intervene,  the  current  stops  of  itself;  the  formative  power  seems  to 
undergo  a  progressive  exhaustion,  until  no  assistance  from  artificial  heat,  no  sup- 
ply of  the  most  nutritious  food,  can  any  longer  avail  for  the  generation  of  new 
tissue;  the  nervo-muscular  energy  gradually  declines,  until  at  last  even  those  ac- 
tions on  which  the  circulation  and  respiration  entirely  depend  can  no  longer  be 
performed ;  and,  with  the  cessation  of  these  functions,  the  Life  of  the  entire  or- 
ganism becomes  extinct. — Such  we  may  consider  to  be  the  mode  in  which  Death 
normally  occurs.  Various  abnormal  influences,  however,  remain  to  be  considered, 
which  may  bring-about  this  final  result  at  an  earlier  period,  and  in  different 
modes  (Chap.  xix). 


CHAPTER  XIX. 

OF   DEATH. 

983.  WE  have  seen  it  to  be  inherent  in  the  very  nature  of  Vital  Action,  that 
it  can  only  be  sustained  during  a  limited  period  by  any  Organized  body ;  for  al- 
though the  duration  of  certain  structures  may  be  prolonged,  and  their  vital  pro- 
perties retained,  almost  indefinitely,  yet  this  is  only  when  the  withdrawal  of  all 
extraneous  agencies  has  reduced  them  to  a  condition  of  complete  inactivity.2  The 
Organized  fabric,  in  fact,  is  at  the  same  time  the  instrument  whereby  Vital  Force 
is  exercised,  and  the  subject  of  its  operation ;  and  of  this  operation,  decline  is  n 
less  a  constituent  part  than  development,  and  Death  is  its  necessary  sequence. 

1  The  experience  of  the  first  two  months  of  the  present  year,  has  afforded  a  remarkable 
confirmation  of  the  statement  previously  made  ($  443)  respecting  the  influence  of  continued 
Cold  in  raising  the  rate  of  mortality.  The  mean  weekly  temperature  for  six  weeks  having 
been  28-4°  (or  9-4°  below  the  average  of  the  season),  the  excess  in  the  number  of  deaths 
above  the  average,  corrected  for  increase  of  population,  has  been  nearly  2000,  or  more 
than  360  per  week.  The  mode  in  which  this  excess  is  distributed,  is  not  a  little  curious ; 
the  numbers  having  been  as  follows : — 

Actual  excess  of  deaths  Deathn  by  cold  to  100,000 

by  cold.  living  at  each  age. 

All  Ages 1968 77 


0—20     419  40 

20—40     200  22 

40—60     392  87 

60—80     752  512 

80  and  upwards 205  2073 

[t  is  only,  of  course,  when  the  actual  number  of  deaths  is  compared  with  the  number  living 
at  each  age,  that  the  relative  fatality  of  cold  at  different  periods  of  life  can  be  rightly  esti- 
mated ;  from  this  comparison  we  see  that  its  minimum  influence  is  exerted  on  individuals 
between  20  and  40  years  of  age,  and  its  maximum  (nearly  100  times  as  great)  on  those 
above  80,  the  fatality  resulting  from  the  reduction  of  temperature  being  doubled  every 
nine  years  after  the  age  of  40. — The  diseases  which  chiefly  contributed  to  this  excess  of 
mortality  were  pneumonia,  bronchitis,  and  asthma;  but  the  deaths  from  many  others 
(chiefly  chronic  diseases)  were  in  excess ;  so  that  it  may  be  affirmed  that  cold  brings 
quickly  to  a  fatal  end  many  maladies  which  it  does  not  directly  induce. — See  the  weekly 
lleport  of  the  Registrar  General  for  March  3,  1855. 
*  See  the  section  on  'Dormant  Vitality'  in  PRINC.  OF  GEN.  PHTS.,  Am.  Ed. 


SOMATIC  AND  MOLECULAR  DEATH:  —  SYNCOPE.   8G5 

Hence,  in  the  performance  of  each  one  of  those  Functions  whose  aggregate 
inakes-up  the  Life  of  Man,  the  particular  organ  which  ministers  to  that  function 
undergoes  a  certain  loss  by  the  decline  and  death  of  its  component  tissues ;  and 
this  the  more  rapidly,  in  proportion  to  the  activity  of  the  changes  which  are  ef- 
fected by  their  instrumentality.  But  if  the  regenerative  processes  be  also  per- 
formed with  due  vigour,  no  deterioration  of  the  organ  is  manifested,  since  every 
loss  of  substance  is  compensated  by  the  production  of  an  equivalent  amount  of 
new  and  similar  tissue.  This  regenerative  power,  however,  gradually  diminishes 
with  the  advance  of  years ;  and  thus  it  happens  that  the  entire  organism  progres- 
sively deteriorates  (§  981),  and  that  Death  at  last  supervenes  from  a  general  fail- 
ure of  the  vital  powers,  rather  than  from,  the  perversion  or  cessation  of  any  one 
class  of  actions  in  particular. 

984.  But  Death  may  occur  at  any  period  of  Life,  from  some  local  interruption 
produced  by  disease  or  injury  in  the  regular  sequence  of  vital  actions  5  such  inter- 
ruption extending  itself  from  the  part  in  which  it  commences,  Jo  the  organism  in 
general,  in  virtue  of  that  intimate  mutual  dependence  of  one  function  upon  an- 
other, which  is  characteristic  of  all  the  higher  orders  of  living  beings.     The  death 
of  the  body  as  a  whole,  which  may  be  appropriately  designated   Somatic*  death, 
becomes  a  necessary  consequence  of  the  death  of  a  certain  part  of  it,  or  Molecular 
death,  only  when  the  cessation  of  activity  in  the  latter  interferes  with  the  elabo- 
ration, the  circulation,  or  the  depuration  of  the  Blood,  which  supplies  not  merely 
the  nutritive  pabulurr,  to  every  part  of  the  organism,  but  also  the  oxygen  which 
is  essential  to  the  activity  of  the  Nervo-muscular  apparatus.     Thus,  even  in  the 
higher  animals,  the  death  or  removal  of  the  limbs,  although  they  may  constitute 
(as  in  Man)^a  large  proportion  of  the  fabric,  is  not  necessarily  fatal;  because  it 
involves  no  interruption,  either  in  the  nutritive  operations  oft  the  viscera,  or  in 
the  sensorial  functions  of  the  brain.2     On  the  other  hand,  the  destruction  of  a 
certain  minute  portion  of  the  Nervous  centres,  or  such  a  lesion  of  the  Heart's 
structure  as  would  be  trivial  in  almost  any  other  organ,  may  be  the  occasion  of 
immediate  death ;  because  these  changes  arrest  the  Respiratory  movements,  or  in- 
terfere directly  with  the  action  of  the  Heart,  so  as  to  bring  the  flow  of  blood  to  a 
stand.     It  sometimes  happens,  however,  that  life  may  be  prolonged  after  the 
death  or  removal  of  some  important  organ,  in  consequence  of  the  power  which 
some  other  possesses  of  discharging  its  function ;  thus  w«3  find  that,  in  Man,  the 
kidneys  seem  occasionally  to  take  upon  themselves  the  elimination  of  the  consti- 
tuents of  bile  from  the  blood  (§  388) ;  and  in  the  Frog,  the  skin  can  perform  part 
of  the  office  of  the  lungs,  so  as  to  effect  the  aeration  of  the  blood  in  a  sufficient 
degree  to  prolong  life  for  some  time,  unless  the  temperature  be  elevated.3 

985.  But  although  the  vital  activity  of  every  parb  of  the  body  is  dependent 
upon  a  due  supply  of  circulating  fluid,  yet  this  dependence  is  usually  not  so  close 
as  to  involve  the  immediate  suspension  of  vital  activity,  or  Molecular  Death,  in 
every  part,  whenever  the  general  Circulation  shall  have  been  brought  to  a  stand. 
For   we   have   distinct  evidence   of  the  persistence  of  vital  changes  in  various 
organs  and  tissues  of  the  body,  after  the  death  of  the  body  at  large  j  as  is  mani- 

1  This  term  was  first  suggested  by  Dr.  Prichard,  in  place  of  the  less  accurate  term 
'systemic'  which  was  previously  in  use.  (See  "Cyclop,  of  Anat.  and  Physiol.,"  vol.  i. 
p.  791.) 

3  The  Author  has  been  informed  by  Dr.  Daniell,  that  it  is  not  at  all  uncommon,  in  Ne- 
groes who  are  in  the  last  stage  of  the  adynamic  fevers  of  the  African  coast,  for  death  and 
decomposition  to  extend  gradually  upwards  from  the  extremities  to  the  trunk ;  so  that  the 
former  may  be  in  a  state  of  absolute  putrescence,  before  the  respiration  and  circulation 
have  been  brought  to  a  stand :  and  he  learns  from  Prof.  Jackson,  of  Philadelphia,  that  ho 
has  more  than  once  witnessed  the  same  occurrence. 

*  That  such  cannot  take-place  in  Man,  is  due  not  merely  to  the  far  less  complete  adap- 
tation of  his  skin  for  the  aeration  of  the  blood,  but  also  to  the  diiference  in  the  type  of  his 
circulation,  which  causes  the  arrest  of  blood  in  the  pulmonary  vessels  to  produce  a  stag- 
nation of  the  entire  current. 
55 


866  OF    DEATH. 

Tested  in  the  performance  of  ciliary  and  of  muscular  movements  (PRINC.  OF  GEN. 
PHYS.,  Am.  Ed.),  in  acts  of  secretion  and  perhaps  even  of  nutrition,1  in  the 
maintenance  of  the  local  circulation,  (§  269),  and  in  the  generation  of  animal 
heat  (§  428) ;  and  the  fact  is  even  yet  more  remarkably  manifested  in  the  reunion 
(even  after  the  lapse  of  some  hours)  of  parts  that  have  been  entirely  severed, 
such  as  fingers  or  toes,  noses  or  ears,  by  adhesion  between  the  cut  surfaces  when 
brought  into  apposition,  which  could  not  take  place  if  the  severed  parts  were 
already  dead. 

986.  The  permanent  and  complete  cessation  of  the  Circulating  current,  which 
essentially  constitutes  Somatic  Death,  may  be  directly  or  indirectly  consequent 
upon  several  distinct  causes. — In  thejirst  place,  it  may  be  due  to  failure  in  the 
propulsive  power  of  the  Heart,  which  constitutes  Syncope.  This  failure  may 
occur  either  (or)  in  consequence  of  a  loss  of  the  proper  irritability  of  the  Muscular 
tissue,  or  (b)  through  the  supervention  of  a  l  tonic  spasm/  the  organ  remaining 
rigidly  contracted  without  its  usual  alternation  of  relaxation.  The  phenomena 
attending  death  in  the  two  cases  are  not  dissimilar,  when  the  loss  of  irritability  is 
sudden  and  immediate  (as  when  it  arises  from  violent  impressions  on  the  nervous 
system);  for  the  individual  suddenly  turns-pale,  falls-back,  or  drops-down,  and 
expires  with  one  gasp.  But  under  the  former  condition,  the  heart  is  found 
flabby,  sometimes  empty,  sometimes  distended  with  blood,  both  cavities  being 
equally  filled;  whilst  in  the  latter,  the  heart  is  contracted  and  hard,  containing 
little  or  no  blood,  as  when  in  the  state  of  rigor  mortis. — The  cause  of  the  loss  of 
irritability,  when  sudden,  usually  lies  in  the  influence  of  a  'shock'  transmitted 
through  the  Nervous  system,  and  originating  either  in  some  seVere  lesion  of  its 
central  organs  or  of  its  peripheral  expansion  (§  238),  or  in  a' deficiency  of  its 
supply  of  blood  or  diminution  of  its  usual  pressure  (such  as  is  produced  by 
rapid  detraction  of  blood,  especially  in  the  erect  posture,  by  the  rapid 
removal  of  the  fluid  in  ascites,  without  the  substitution  of  artificial  pressure,  or 
by  suddenly  rising  into  the  erect  posture  after  prolonged  recumbency,2  still  more, 
after  long  stooping),  or  in  some  powerful  mental  emotion,  either  exciting  or  de- 
pressing. A  more  gradual  effect  of  the  same  kind  is  produced  by  severe  lesions 
of  the  internal  organs  (such  as  rupture  of  the  uterus),  which  often  prove  fatal  by 
the  general  '  collapse '  thus  induced,  rather  than  by  the  disturbance  which  takes- 
place  in  their  own  proper  functions ;  and  this  seems  to  be  the  usual  modus  ope- 
randi  of  corrosive  poisons,  whose  effect  upon  the  heart's  action  resembles  that 
produced  by  severe  burns  of  the  surface  in  children.  The  influence  of  the  proper 
sedative  poisons,  however, — such  as  digitalis,  tobacco,  aconite,  and  upas, — seems 
to  be  directly  exerted,  through  the  blood,  upon  the  tissue  of  the  heart  itself;  and 
the  same  is  probably  the  case  with  some  of  those  '  morbid  poisons/  whose  intro- 
duction into  the  system  give  rise  to  diseases  of  the  most  intensely  adynamic  type, 
such  as  Malignant  Cholera,  in  which  the  '  collapse '  is  out  of  all  proportion  to  any 
local  lesion.  But,  again,  the  loss  of  the  Heart's  irritability  may  be  a  gradual 
process,  resulting  from  the  deterioration  of  its  tissue  by  fatty  degeneration  or  by 
simple  atrophy ;  and  this  last  condition  may  be  due  to  deficiency  of  blood,  as 
happens  in  chronic  starvation  and  diseases  of  exhaustion,  in  which  the  failure  of 
the  circulation  seems  due  to  the  weakening  of  the  heart's  power  and  to  the  lower- 

1  Thus  Mr.  T.  Bell  mentions  ("History  of  British  Reptiles,"  p.  61),  that  having  been 
engaged  in  the  careful  dissection  of  the  poison-apparatus  of  a  large  Rattlesnake,  although 
the  animal  had  been  dead  for  some  hours,  and  the  head  had  been  taken-off  immediately 
after  death,  yet  the  poison  continued  to  be  secreted  as  the  dissection  proceeded,  so  as  to 
require  to  be  occasionally  dried-off  with  a  bit  of  sponge. — A  growth  of  Hair  is  said  to  have 
been  noticed  in  several  instances  after  death  ;  and  if  the  temperature  of  the  surrounding 
medium  be  not  too  low  for  the  vital  activity  of  the  hair-bulbs,  there  seems  no  adequate 
reason  why  this  should  not  take- place. 

a  Hence  it  is  that  great  caution  should  be  exercised,  in  allowing  patients  who  are  con- 
valescent from  acute  diseases  to  rise  into  the  erect  position  ;  many  cases  of  fatal  syncope 
having  been  thus  induced.  The  state  of  general  debility,  and  the  continued  recumbency, 
both  favour  this  result;  especially  in  persons  advanced  in  life. 


SOMATIC  DEATH;  ASPHYXIA,  NECTLEMIA. — MOLECULAR  DEATH.    867 

ing  of  the  quantity  and  quality  of  the  blood,  acting  as  concurrent  causes,  the  con- 
dition thus  induced  being  appropriately  designated  Asthenia.  In  all  cases  it  is 
to  be  observed,  that  when  the  Vital  powers  have  been  previously  depressed,  a  much 
slighter  impression  on  the  Nervous  system  is  adequate  to  produce  Syncope,  than 
would  be  required  when  it  is  in  a  state  of  full  vigour. — The  causes  of  the  tonic 
spasm  of  the  heart  have  not  been  clearly  made-out ;  but  it  seems  producible,  like 
the  more  common  form  of  Syncope,  by  agencies  operating  through  the  Nervous 
system ;  thus  it  has  supervened  upon  the  ingestion  of  a  large  quantity  of  cold 
water  into  the  stomach. 

987.  Somatic  Death  may  be  occasioned,  secondly,  by  an  obstruction  to  the  flow 
of  blood  through  the  capillaries  of  the  lungs,  constituting  Asphyxia  (§  326) ;  and 
this  may  be  consequent  upon  a  disordered  state  of  the  lungs  themselves,  or  upon 
suspension  of  the  respiratory  movements  through  affections  of  the  Nervous  cen- 
tres.    It  is  in  this  mode  that  most  fatal  disorders  of  the  Nervous  System  produce 
death,  except  when  a  sudden  and  violent  impression  occasions  a  cessation  of  the 
heart's  power;  thus  in  Apoplexy,  Narcotic  Poisoning,  &c.,  death  results  from 
the  paralyzed  condition  of  the  Medulla  Oblongata  :  whilst  in  Convulsive  diseases, 
the  fatal  result  generally  ensues  upon  a  spasmodic  fixation  of  the  respiratory  mus- 
cles.—  Thirdly,  Somatic  Death  may  be  occasioned  by  a  disordered  condition  of 
the  Blood  itself  (§  194),  which  at  the  same  time  weakens  the  power  of  the 
Heart,  impairs  the  activity  of  the  Nervous  system,  and  prevents  the  performance 
of  those  changes  in  the  systemic  Capillaries,  which  afford  a  powerful  auxiliary  to 
the  circulation.     This  is  Death  by  Necrsemia* — Fourthly,  Somatic  death  may 
result  directly  from  the  agency  of  Cold,  which  stagnates  all  the  vital  operations 
of  the  system.     Where  the  cooling  is  due  to  the  agency  of  an  extremely  low  ex- 
ternal temperature,  which  acts  first  upon  the  superficial  parts,  there  is  reason  to 
think  that  the  congestion  of  the  internal  vessels  thereby  induced,  occasions  a  tor- 
pid condition  of  the  Nervous  centres,  and  that  the  cessation  of  the  Circulation  is 
immediately  due  to  Asphyxia.     But  when  the  cooling  is  gradual,  and  the  loss  of 
heat  is  almost  equally  rapid  throughout,  it  is  obvious  that  the  stagnation  must 
be  universal,  and  that  no  cessation  of  activity  in  any  one  part  is  the  occasion  of 
the  torpor  in  the  functions  of  the  remainder^     It  is  in  this  manner  that  death 
ordinarily  results  from  Starvation,  and  not  by  the  weakening  of  the  heart's  action, 
as  commonly  supposed ;  the  proofs  of  this  have  been  already  stated  (§  433). 

988.  As  a  general  rule,  we  find  that  the  more  active  the  changes  which  nor- 
mally take  place  in  any  tissue  during  life,  the  more  speedily  does  its  Molecular 
Death  follow  Somatic  Death,  the  requisite  conditions  of  its  vital  action  being  no 
longer  supplied  to  it.    Thus  we  observe  that,  in  Cold-blooded  animals,  the  super- 
vention of  Molecular  upon  Somatic  death  is  much  less  speedy  than  it  is  in  Birds 
and  Mammals.     This  seems  due  to  two  causes.     In  the  first  place,  the  tissues  of 
the  former,  being  at  all  times  possessed  of  a  lower  degree  of  vital  activity  than 
those  of  the  latter,  are  disposed  to  retain  it  for  a  longer  time ;  according  to  the 
principle  already  laid-down.     And,  secondly,  as  the  maintenance  of  a  high  tem- 
perature is  an  essential  condition  of  the  vital  activity  of  the  tissues  of  warm- 
blooded animals,  the  rapid  cooling  of  the  body  after  Somatic  death  is  calculated 
to  extinguish  it  speedily }  and  that  this  cause  has  a  real  operation,  is  evinced  by 
the  influence  of  artificial  warmth  in  sustaining  the  vital  properties  of  separated 
parts. — The  rapidity,  however,  with  which  Molecular  death  follows  the  cessation 
of  the  general  circulation,  will  be  influenced  by  a  variety  of  causes;  but  especi- 
ally by  the  degree  in  which  the  condition  of  the  solids  and  fluids  of  the  body 
has  been  impaired  by  the  mode  of  death.     Thus  in  Necrsemia,  Asthenia,  and 
death  by  gradual  cooling,  Molecular  and  Somatic  death  may  be  said  to  be  simul- 
taneous j  and  the  same  appears  to  be  true  of  death  by  sudden  and  violent  impres- 
sions on  the  Nervous  system  (§  238).     But  in  many  cases  of  death  by  causes 
which  operate  by  producing  a  more  gradual  Syncope  or  Asphyxia,  the  tissues  and 

1  See  Dr.  J.  C.  B.  Williams's  "Principles  of  Medicine,"  3d  Am.  Ed.,  p.  484. 


868  OF    DEATH. 

blood  having  been  previously  in  a  healthy  condition,  Molecular  death  may  bo 
long  postponed ;  and  we  cannot  be  quite  certain  that  it  has  supervened,  until 
signs  of  actual  decomposition  present  themselves. 

989.  When   Molecular  death  takes-place  in  an  isolated  part,  it  must  result 
from  some  condition  peculiar  to  that  part,  and  not  primarily  affecting  the  body  in 
general.     Thus  we  may  have  Gangrene  or  Mortification  of  a  limb  as  a  direct 
result  of  the  application  of   severe  cold,  or  of  an  agent  capable  of  producing 
chemical  changes  in  its  substance,  or  of  violent  contusions  occasioning  mechani- 
cal injury;  or,  again,  from  an  interruption  to  the  current  of  nutritive  fluid;  or, 
further,   from   some   ill-understood   stagnation   of  the   nutritive  process,  which 
manifests  itself  in  the  spontaneous  death  of  the  tissues  without  any  assignable 
cause,  as  in  some  cases  of  senile  gangrene.     Sometimes  we  are  enabled  to  trace 
this  stagnation  to  a  disordered  condition  of  the  circulating  fluid ;  as  in  the  gan- 
grene resulting  from  the  continued  use  of  the  'ergot'  of  rye  or  wheat;  but  we 
can  give  no  other  account  of  the  almost  invariable  commencement  of  such  gan- 
grene in  the  extremities,  than  we  can  of  the  selection  of  lead,  introduced  into 
the  blood,  by  the  extensors  of  the  forearm. — If  Mortification  or  Molecular  Death 
be  once  established  in  any  part,  it  tends  to  spread,  both  to  contiguous  and  to 
distant  portions  of  the  body.     Thus  we  have  continually  to  witness  the  extension 
of  gangrene  of  the  lower  extremities,  resulting  from  severe  injury  or  from   the 
use  of  the  ergot,  from  the  small  part  first  affected,  until  the  whole  limb  is  in- 
volved ;  and  this  extension  is  easily  accounted-for,  by  our  knowledge  of  the  ten- 
dency of  organic  substances  in  the  act  of  decomposition,  to  produce  a  similar 
change  in  other  organic  substances  subjected  to  the  influence  of  proximity  to 
them.     And  the  propagation  of  the  gangrenous  tendency  to  remoter  parts,  is 
obviously  due  to  the  perversion  of  the  qualities  of  the  Blood,  which  results  from 
a  similar  cause.1 

990.  It  is  quite  certain  that  an  apparent  cessation  of  all  the  vital  functions 
may  take-place,  without  that  entire  loss  of  vitality,  which  would  leave  the  organ- 
ism in  the  condition  of  a  dead  body,  liable  to  be  speedily  disintegrated  by  the 
operation  of  chemical  and  physical  agencies.     The  state  of  Syncope  is  sometimes 
so  complete,  that  the  heart's  action  cannot  be  perceived,  nor  any  respiratory 
movements  be  observed,  all  consciousness  and  power  of  movement  being  at  the 
same  time  abolished ;  and  yet  recovery  has  spontaneously  taken  place,  which 
could  scarcely  have  been  the  case,  if  all  vital  action  had  been  suspended.  —  It  is 
not  a  little  remarkable,  that  certain   individuals  have  possessed  the  power  of 
voluntarily  inducing  this  condition,     The  best-authenticated  case  of  this  kind  is 
that  of  Col.  Townsend,  which  was  described  by  Dr.  Greorge  Cheyne,2  who  was 
himself  the  witness  of  the  fact.     But  statements  have  been  recently  made  re- 
specting the  performance  of  certain  Indian  Fakeers,  which  are  far  more  extraor- 
dinary ;  it  being  demonstrated,  if  these  assertions  are  to  be  credited,3  that  the 

1  On  the  proximate  causes  of  Death,  see  especially  the  Art.  « Death,'  by  Dr.  Symonds, 
in  the  "  Cyclop,  of  Anat.  and  Phys.,"  vol  i. ;  the  first  chapter  of  Prof.  Alison's  "Outlines 
of  Pathology  and  Practice  of  Medicine,"  and  Dr.  C.  J.  B.  Williams's  "  Principles  of  Medi- 
cine," 2d  edit.,  pp.  376—382,  Am.  Ed. 

5  See  his  "  Treatise  on  Nervous  Diseases,"  p.  307. 

3  See  a  collection  of  these  cases,  directly  obtained  from  British  officers  who  had  been 
eye-witnesses  of  them  in  India,  by  Mr.  Braid,  in  his  "  Observations  on  Trance,  or  Human 
Hybernation,"  1850. — In  one  of  these,  vouched-for  by  Sir  Claude  M.  Wade  (formerly 
political  agent  at  the  Court  of  Runjeet  Singh),  the  Fakeer  was  buried  in  an  underground 
cell,  under  strict  guardianship,  for  six  weeks ;  the  body  had  been  twice  dug  up  by  Runjeet 
Singh  during  the  period  of  interment,  and  had  been  found  in  the  same  position  as  when 
first  buried. — In  another  case,  narrated  by  Lieut.  Boileau,  in  his  "Narrative  of  a  Jour- 
ney in  Rajwarra,  in  1835,"  the  man  had  been  buried  for  ten  days,  in  a  grave  lined  with 
masonry  and  covered  with  large  slabs  of  stone,  and  strictly  guarded ;  and  he  assured 
Lieut.  B.  that  he  was  ready  to  submit  to  an  interment  of  a  twelvemonth's  duration,  if 
desired.  —  In  a  third  case  narrated  by  Mr.  Braid,  the  trial  was  made  under  the  direct 


APPARENT   DEATH:  —  SIGNS   OF  DEATH.  869 

Human  organism  may  not  only  be  voluntarily  reduced  to  a  state  resembling  pro- 
found collapse,  in  which  there  appears  to  be  a  nearly  complete  suspension  of  all 
its  vital  operations,  but  may  continue  in  that  condition  for  some  days  or  even 
weeks,  until,  in  fact,  means  are  taken  to  produce  resuscitation.  —  Another  form 
of  apparent  death,  the  existence  of  which  appears  to  be  well-authenticated,  is 
that  sometimes  designated  as  « Trance '  or  <  Catalepsy/  in  which  there  is  a  reduc- 
tion of  all  the  Organic  Functions  to  an  extremely  low  ebb,  but,  in  which  Con- 
sciousness is  still  preserved,  whilst  the  power  of  voluntary  movement  is  sus- 
pended ;  so  that  the  patient,  though  fully  aware  of  all  that  is  being  said  and  done 
around,  is  unable  to  make  the  least  visible  or  audible  sign  of  life.1  It  is  impos- 
sible, in  the  present  state  of  our  knowledge,  to  give  any  satisfactory  account  of 
these  states;  but  some  light  appears  to  be  thrown  upon  them  by  certain  pheno- 
mena of  artificial  Somnambulism,  l  hypnotic'  or  'mesmeric'  (§§  694-6);  for  in 
this  condition,  there  is  sometimes  an  extraordinary  retardation  of  the  respiratory 
movements  and  of  the  pulsations  of  the  heart,  which,  if  carried  further,  would 
produce  a  state  of  complete  collapse ;  and  its  self-induction  is  suspected  by  Mr. 
Braid  to  be  the  secret  of  the  performance  of  the  Indian  Fakeers  just  re- 
ferred-to. 

991.  The  signs  by  which  real  is  certainly  distinguishable  from  apparent 
Death,  are  not  numerous,  a  large  proportion  of  those  commonly  relied-on  being 
fallacious;  but  they  are  conclusive. — In  the  first  place,  it  is  to  be  remarked,  that 
no  reliance  is  to  be  placed,  for  the  reasons  already  mentioned,  upon  the  apparent 
cessation  of  the  Heart's  action  and  of  the  Respiratory  movements ;  since  the  re- 
duction of  these  to  so  low  a  condition  that  they  are  no  longer  distinguishable,  is 
by  no  means  incompatible  with  the  persistence  of  vitality.  A  surer  test,  how- 
ever, is  afforded  by  the  condition  of  the  Muscular  substance;  for  this  gradually 
loses  its  irritability  after  real  Death,  so  that  it  can  no  longer  be  excited  to  con- 
traction by  electrical  or  any  other  kind  of  stimulation;  and  the  loss  of  irritability 
is  succeeded  by  the  appearance  of  cadaveric  rigidity.  So  long,  then,  as  the 
muscle  retains  its  irritability  and  remains  free  from  rigidity,  so  long  we  may  say 
with  certainty  that  it  is  not  dead ;  and  the  persistence  of  its  vitality  for  an  unusual 
period,  affords  a  presumption  in  favour  of  the  continuance  of  some  degree  of 
vital  action  in  the  body  generally;  whilst,  on  the  other  hand,  the  entire  loss  of 
irritability,  and  the  supervention  of  rigidity,  afford  conclusive  evidence  that 
death  has  occurred.  The  most  satisfactory  proof,  however,  is  given  by  the  occur- 
rence of  putrefaction;  this  usually  first  manifests  itself  in  the  blue-green  colora- 
tion of  the  cutaneous  surface,  especially  the  abdominal ;  but  it  speedily  becomes 
apparent  in  other  parts,  its  rate  being  usually  in  some  degree  of  accordance  with 
the  external  temperature,  though  also  much  influenced  by  the  previous  condition 
of  the  solids  and  fluids  of  the  body,  these  having  been  sometimes  left  by 
diseased  actions  in  a  state  that  renders  them  peculiarly  prone  to  disintegra- 
tion  (§  72). 

superintendence  of  a  British  Officer,  a  period  of  nine  days  having  been  stipulated-for  on 
the  part  of  the  devotee  ;  but  this  was  shortened  to  three  at  the  desire  of  the  Officer,  who 
feared  lest  he  should  incur  blame  if  the  result  was  fatal.  —  The  appearance  of  the  body 
when  first  disinterred,  is  described  in  all  instances  as  having  been  quite  corpse-like,  and 
no  pulsation  could  be  detected  at  the  heart  or  in  the  arteries;  the  means  of  restoration 
employed  were  chiefly  warmth  to  the  vertex,  and  friction  to  the  body  and  limbs. — It  may 
be  remarked  that  the  possibility  of  the  protraction  of  such  a  state  (supposing  that  no 
deception  vitiates  the  authenticity  of  the  narratives  referred-to)  can  be  much  better  com- 
prehended as  occurring  in  India,  than  as  taking-place  in  this  country  ;  since  the  warmth 
of  the  tropical  atmosphere  and  soil  would  prevent  any  serious  loss  of  heat,  such  as  must 
soon  occur  in  a  colder  climate,  when  the  processes  whereby  it  is  generated  are  brought  to 
a  stand. 

1  Several  such  cases  are  recorded  in  Dr.  H.  Mayo's  "  Letters  on  the  Truths  contained 
in  Popular  Superstitions,"  and  also  by  Mr.  Braid,  Op.  cit. 


870  OF    DEATH. 

992.  With  the  final  restoration  of  the  components  of  the  Human  Organism 
to  the  Inorganic  Universe,  in  those  very  forms  (or  nearly  so)  in  which  they  were 
first  withdrawn  from  it,  the  Corporeal  Life  of  Man,  of  which  it  has  been  the 
object  of  the  foregoing  Treatise  to  sketch  the  leading  features,  comes  to  a  final 
close.  But  the  Death  of  the  Body  is  but  the  commencement  of  a  new  Life  of 
the  Soul ;  in  which  (as  the  religious  physiologist  delights  to  believe)  all  that  is 
pure  and  noble  in  Man's  nature  will  be  refined,  elevated,  and  progressively 
advanced  towards  perfection;  whilst  all  that  is  carnal,  selfish,  and  degrading,  will 
be  eliminated  by  the  purifying  processes  to  which  each  individual  must  be  sub- 
jected, before  Sin  can  be  entirely  subjugated,  and  Death  can  be  completely 
"  swallowed  up  of  Victory." 


INDEX   OF   AUTHORS. 


A. 

ABERCROMBIE,  Dr.,  on  dreaming,  617  note, 
618  note;  his  case  of  spectral  illusions, 
641,  642  note. 

Addison,  Mr.,  on  colourless  corpuscles,  178, 
222. 

Addison,  Dr.  W.,  on  measurement  of  air- 
cells,  286. 

Agassiz,  Prof.,  on  psychical  conformity  of 
human  races,  835  note. 

Alcock,  Dr.,  on  nerves  of  taste,  465. 

Alison,  Prof.,  on  buffy  coat,  213;  on  mus- 
cular irritability,  715;  on  asphyxia,  re- 
ferred-to,  316,  note;  on  jaundice  from 
suppression  of  hepatic  excretion,  379 
note ;  on  guiding  sensations,  506 ;  on 
rapidity  of  muscular  actions,  715-716  ;  OH 
death,  referred-to,  868  note. 

Allen  and  Pepys,  their  experiments  on  re- 
spiration, 302. 

Ancell,  Mr.  on  red  corpuscles  of  the  blood, 
referred-to,  173  note;  on  coagulation  of 
the  blood,  210  note. 

Andral,  M.,  on  abnormal  conditions  of  blood, 
202,  203  :  on  temperature  in  disease,  409 ; 
on  pathology  of  corpora  striata  and  tha- 
lami  optici,  502 ;  on  pathology  of  Cere- 
bellum, 516. 

Andral  and  Gavarrett,  MM.,  on  effect  of 
bleeding  and  starvation  on  amount  of 
fibrin,  217  note ;  on  effects  of  improvement 
of  breed  on  fibrin,  218  note;  on  composi- 
tion of  blood  in  health,  185  note;  on  com- 
position of  blood  in  disease,  199-205  ;  on 
buffy  coat,  214,  215  ;  on  expiration  of 
carbonic  acid,  305,  306. 

Anselmino,  on  solid  matters  of  perspiration, 
402. 

Arnold,  on  development  of  Spleen,  162. 

Arnott,  Dr.,  on  the  venous  circulation,  277  ; 
on  stammering,  731  note,  732. 

Atkinson,  Mr.  H.  G.,  on  materialism,  538 
note. 

B. 

Babington,   Dr.,  on   coagulation   of  blood, 

210 ;  his  translation  of  Hecker,  590  note. 
Bagge,  Dr.,  on  embryonic  development  of 

Entozoa,  785  note. 
Baillarger,  M.,  on  grey  matter  of  Cerebrum, 

525  note ;   on  hallucinations,  635  note. 
Bain,  Mr.  Alex.,  on  laws  of  Association,  580 

note. 


Ballou,  Dr.,  on  suspended  lactation,  817  note. 

Baly,  Dr.,  on  mechanical  excitement  of 
olfactive  and  gustative  sensations,  652, 
689 ;  on  corpus  luteum,  762. 

Barker,  Dr.,  his  case  of  early  viability,  777. 

Barlow,  Mr.  F.,  on  fatty  degeneration,  863 
note. 

Barlow,  Rev.  J.,  on  self-control,  633  note. 

Barral,  M.,  on  amount  of  carbon  excreted, 
308;  on  excretion  of  nitrogen,  310;  OB 
excretion  of  hydrogen,  311 ;  on  statistics 
of  excretion,  862. 

Barreswell,  on  uraemia,  389. 

Barruel,  M.,  on  odorous  principles  of  blood, 
187  note. 

Barry,  Dr.  Martin,  on  ovisac,  754,  755 ;  on 
penetration  of  spermatozoa  into  ovum,  764 
note  ;  on  changes  in  germinal  vesicle,  764. 

Baxter,  Mr.,  on  disturbance  of  electric 
equilibrium  in  secretion,  423. 

Beale,  Dr.,  on  fluid  of  thymus,  165. 

Beau  and  Maissat,  MM.,  on  mechanum  of 
respiration,  298  note. 

Beaumont,  Dr.,  on  sense  of  satiety,  71 ;  on 
movement  of  stomach,  94 ;  on  secretion 
of  gastric  juice,  111,  112;  on  disordered 
states  of  the  stomach,  112,  113 ;  on  gastric 
digestion,  115,  117  ;  on  cause  of  hunger, 
80 ;  on  function  of  bile  in  digestion,  125. 

Beck,  Dr.,  on  superfoetation,  779  note. 

Becker,  Von,  on  sugar  in  blood,  191. 

Be'clard,  M.,  on  blood  of  mesenteric  vein, 
196;  on  blood  of  splenic  vein,  197. 

Becquerel  and  Breschett,  MM.,  on  cutaneous 
asphyxia,  414. 

Becquerel  and  Rodier,  MM.,  on  mode  of 
analysing  blood,  185  note  ;  on  influence 
of  sex,  189 ;  on  effect  of  loss  of  blood, 
192  ;  on  composition  of  blood  in  disease, 
199-205 ;  on  increase  of  cholesterin  in 
blood  of  old  persons,  229 ;  their  estimate 
of  fatty  matters  of  blood,  187. 

Begbie,  Dr.,  on  Bright's  disease,  387  note. 

Begin,  M.,  his  case  of  section  of  spinal 
cord,  474  note. 

Belfield-Lefevre,  M.,  on  tactile  sensibility, 
655  note. 

Bell,  Sir  C.,  on  the  hand,  4;  on  respiratory 
nerves  and  muscles,  292,  293 ;  on  dif- 
tinct  functions  of  anterior  and  posterior 
roots  of  spinal  nerves,  442  ;  on  cephalic 
nerves,  445  ;  on  Medulla  Oblongata,  456 
note;  on  decussation  of  posterior  pyra- 
(871) 


872 


INDEX    OF    AUTHORS. 


mids,  458 ;  on  motor  and  sensory  tracts 
of  Medulla  Oblongata,  459,  460 ;  on  fifth 
pair,  87 ;  on  prehension  of  food,  87  ;  on 
spinal  accessory,  468 ;  on  columns  of 
Spinal  Cord,  473  ;  on  guiding  sensations, 
505 :  on  partial  paralysis,  569  note; 
his  neurological  discoveries,  648  note. 

Bell,  Mr.  T.,  on  secretion  of  serpent-poison 
after  death,  866 ;  on  Australian  Dingo, 
832  note. 

Bellehomme,  M.,  on  effects  of  pressure  on 
crus  cerebelli,  501  note. 

Bellingeri,  on  columns  of  Spinal  Cord,  476. 

Bement,  Mr.,  his  cases  of  protracted  gesta- 
tion, 778. 

Bennett,  Prof.  J.  H.,  on  leucocythsemia, 
203  ;  on  colourless  corpuscles,  222 ;  on 
epithelium-cells  of  intestinal  villi,  136 
note;  on  production  of  blood-corpuscles 
in  ductless  glands,  167  ;  his  cases  of  pro- 
duction of  sensations  by  ideas,  552. 

Berard,  M.  Paul,  on  albuminose,  197. 

Berger  and  Delaroche,  MM.,  their  experi- 
ments on  endurance  of  heat,  411. 

Bernard,  M.  Claude,  on  blood  of  hepatic 
vein,  198;  on  salivary  secretion,  102, 
104 ;  on  state  of  gastric  follicles  in  inter- 
vals bet-ween  digestion,  107;  on  compo- 
sition of  gastric  juice,  108;  on  secretion 
of  gastric  juice,  111,  112;  influence  of 
nervous  system  on,  113;  on  gastric  diges- 
tion, 118;  on  pancreatic  fluid,  121,  122; 
on  influence  of  bile  on  digestion,  125 ; 
on  intestinal  digestion,  127  :  on  reflux  of 
blood  to  the  kidneys,  142  note  ;  on  func- 
tions of  liver,  151,  152,  381 ;  on  ursemia, 
389  note;  on  artificial  diabetes,  399  note; 
on  influence  of  lesion  of  Sympathetic  on 
animal  heat,  416 ;  on  motor  roots  of  pneu- 
mogastric,  466;  on  spinal  accessory,  469: 
on  chorda  tympani,  494;  on  gastric  folli- 
cles, 81  note;  on  blood  of  renal  vein,  219 
note ;  on  albumen,  223,  224. 

Berzelius,  his  analysis  of  bile,  377 ;  of 
urine,  391. 

Bidder,  on  structure  of  Kidney,  381  note. 

Bidder  and  Schmidt,  on  saliva,  101,  104; 
on  gastric  juice,  109,  110,  114;  on  pan- 
creatic fluid,  122;  on  digestive  func- 
tion of  bile,  126;  on  intestinal  juice,  127, 
128:  on  bile  in  fseces,  131  ;  on  quantity 
of  chyle  and  lymph,  157  ;  on  exhalation 
of  carbonic  acid,  306  ;  on  excretions  of 
carnivora,  350 ;  on  metamorphosis  of 
flesh,  362  ;  on  change  of  matter  necessary 
for  organic  functions,  362.  363  ;  on  cir- 
cumstances affecting  secretion  of  bile, 
360,  380,  381  ;  on  excretion  of  urea,  392; 
on  influence  of  pneumogastric  nerves  on 
gastric  secretion,  739. 

Bird,  Dr.  Golding,  on  colouring-matters  of 
urine,  394  note;  on  oxalates  in  urine, 
396;  on  action  of  diuretics,  400,  401. 

Birkett,  Mr.,  on  anatomy  of  breast,  813- 
814. 

Bisehof,  Prof.,  on  excretion  of  urea,  391, 
392. 


Bischoff,  Prof.,  on  gases  of  blood,  193;  on 
transfusion  of  blood.  216;  on  excretion 
of  carbonic  acid,  307;  on  penetration  of 
spermatozoon,  764  note;  on  evolution  of 
ovum,  754  :  on  formation  of  chorirm,  765  ; 
on  embryonic  development  of  Mammalia, 
785  note ;  on  development  of  spleen,  162; 
on  movements  of  stomach.  95  note. 

Bishop.  Mr.,  on  motion,  71 1  note;  on  phy 
siology  of  Voice,  724  note,  726 ;  on  stam 
mering,  732  note. 

Bizot,  M.,  on  thickness  of  heart's  parietes, 
250. 

Blagden,  Dr.,  on  endurance  of  heat,  411. 

Blake,  Prof.,  his  estimate  of  amount  of 
blood,  171  note;  on  the  rate  of  circula- 
tion, 254,  255. 

Blane,  Sir  G.,  on  reflex  action,  479. 

Blondlot,  M.,  on  secretion  of  gnstric  juice, 
111  :  on  gastric  digestion,  118;  on  action 
of  bile  in  digestion,  126;  on  quantity  of 
bile  secreted,  126  ;  on  acid  of  cseeum.  128. 

Blumenbach,  Prof.,  on  races  of  Mankind, 
836,  837. 

Board  of  Health,  Report  of,  on  Cholera, 
76  note,  320-324. 

Bocker,  Dr.,  on  tea,  coffee  and  alcohol,  78, 
79;  on  influence  of  tea.  399:  on  influence 
of  alcohol  on  urine,  400. 

Boileau,  Lieut.,  his  case  of  trance,  868 
note. 

Boileau-Castelnau,  M.,  on  Maison  Centrale 
of  Nismes,  85. 

Bois-Reymond,  M.  Du,  on  electric  disturb- 
ance by  organic  processes,  423  note ;  by 
muscular  contraction,  426;  on  muscular 
current,  423,  426 ;  on  nervous  current, 
427,  429  ;  on  lateral  transmission  of  elec- 
tricity in  nerves,  444. 

Bouchardat  and  Sandras,  MM.,  on  blood  of 
mesenteric  veins,  196;  on  action  of  pan- 
creatic fluid  on  fats,  123. 

Bouillaud,  M.,  his  experiments  on  Cere- 
bellum, 515. 

Bourdon,  M.,  on  respiratory  movements, 
293  note. 

Boussingault,  M.,  on  exhalation  of  nitrogen, 
310;  on  excretions  of  herbivora,  361. 

Boutigny,  M.  De,  on  spherical  state  of 
vapour,  411  note. 

Bowman,  Mr.,  on  fatty  liver,  372 :  on 
structure  of  kidney,  381  note;  on  func- 
tions of  Malpighian  bodies  of  kidney, 
384;  on  structure  of  retina,  671:  on 
peculiar  form  of  double  vision,  711  note; 
(See  Todd  and  Bowman). 

Brachet,  M.,  on  sense  of  hunger,  81  ;  on 
movements  of  stomach,  96. 

Braid,  Mr.,  on  Hypnotism,  596,  619-621  ;i 
on  influence  of  attention  on  organic  func- 
tions, 745;  his  cases  of  trance,  868 
note. 

Bramond,  Dr.,  on  absorption  of  Wourali,  145. 

Brewster,  Sir  D.,  on  centre  of  visual  direc- 
tion, 677;  on  natural  mag:c,  698  notp  • 
on  the  stereoscope,  679  note;  on  visual 
irradiation,  687. 


INDEX    OF    AUTHORS. 


873 


Bright,  Dr.,  on  fatty  discharges,  224;  on 
urea  in  blood,  388. 

Bristowe,  Dr.,  on  fibrous  tumours  of  uterus, 
340  note. 

Brittan,  Dr.,  his  observations  on  cholera  at 
Bridgewater,  76  note. 

Brodie,  Sir  B.,  on  influence  of  pneumo- 
gastric  on  secretions  of  stomach,  114;  on 
dependence  of  animal  heat  upon  nervous 
system,  415,  416 ;  on  morbid  sensations, 
651. 

Brooke,  Mr.  C.,  on  tympanic  muscles,  696 
note. 

Brown-Se"quard,  M.,  on  spontaneous  rhyth- 
mical contractions  of  muscles,  246  note; 
on  hypertrophy  of  supra-renal  capsules, 
following  injury  of  Spinal  Cord,  162,  163 
note;  on  reunion  of  divided  Spinal  Cord, 
473  note-,  on  influence  of  nerves  on  nu- 
trition, 743  ;  on  gastric  glands,  107 ;  on 
eifect  of  defibrinated  blood  injected  in 
dead  bodies,  218  note ;  on  cause  of  heart's 
action,  243  note;  on  decussation  of  sen- 
sory fibres  on  Spinal  Cord,  475 ;  on  etfect 
of  division  of  sympathetic  nerve  on  ani- 
mal heat,  417;  on  results  of  wounds  of 
nervous  system.  499. 

Bruch,  Prof.,  on  structure. of  villi,  134;  on 
absorption  of  fat,  143;  on  change  of 
colour  of  blood,  196  ;  on  Peyerian  glands, 
153  note. 

Brucke,  on  Peyerian  glands,  152,  153;  on 
absorbent  glands,  152. 

Buchanan,  Prof.,  on  milky  serum,  190. 

Budd,  Dr.  G.,  on  morbid  changes  in  hepatic 
structure,  375,  376 ;  on  jaundice  from 
suppression  of  hepatic  excretion,  379 
note ;  on  reabsorption  of  bile,  380  note. 

Budd,  Dr.  W.,  on  symmetrical  diseases, 
226,  227 ;  on  localization  of  inflamma- 
tory action,  350;  on  paralysis  of  the 
tongue,  470;  his  cases  of  paraplegia, 
479,  481 ;  on  continuance  of  automatic 
movements,  486. 

Budge,  Dr.,  on  columns  of  Spinal  Cord, 
477. 

Budge  and  Waller,  Drs.,  on  dilatation  of 
pupil  by  sympathetic,  675. 

Burdach,  on  vicarious  secretion  of  urine, 
364,  365:  on  pathology  of  Cerebellum, 
519 ;  on  influence  of  passion  on  mam- 
mary secretion,  743  note. 

Burrows,  Dr.  G.,  on  intra-cranial  circula- 
tion, 279  note;  on  organization  of  blood 
clots,  208  note. 

Bushnell,  Rev.  H.,  on  unconscious  influ- 
ences, 589  note. 

Busk,  Mr.  G.,  on  blood  in  Scurvy,  202. 


C. 


Carlyle,  Thomas,  on  Coleridge,  586  note. 
Carter,   Mr.  R.   B.,  on  hysteria,  634  note; 

on    influence    of    emotions    on  nutrition, 

745. 
Chambers.  Dr.  T.,  on  accessory  food,  78. 


Chatin  and  Bouvier,  MM.,  on  blood  in 
scurvy,  201,  202. 

Chaussier,  M.,  on  weight  of  new-born  in- 
fants, 810. 

Cheselden,  his  case  of  cataract,  676. 

Chevreul,  M.,  on  rhythmical  oscillations, 
592  note;  on  divining  rod,  594  note;  on 
colours,  687. 

Cheyne,  Dr.  G.,  on  case  of  Col.  Townsend, 
868. 

Chossat,  M.,  his  experiments  on  starvation, 
51,  82,  83,  85,  224  note,  413,  414;  on 
diurnal  variation  of  temperature,  307, 
408 ;  on  dependence  of  animal  heat  upon 
nervous  system,  416. 

Christison,  Dr.,  on  blood  in  albuminuria, 
204 ;  on  milky  serum,  204 ;  on  urea  in 
blood,  388  note. 

Clarke,  Mr.  J.  L.,  on  structure  of  Spinal 
Cord,  448,  455 ;  on  roots  of  spinal  acces- 
sory, 468 ;  on  columns  of  Spinal  Cord, 
473. 

Clarke,  Dr.  Joseph,  on  infantile  mortality, 
325 ;  on  weight  of  new-born  infants, 
810. 

Coathupe,  Mr.,  on  amount  of  air  respired, 
299,  301 ;  on  products  of  combustion  of 
charcoal,  313  note. 

Codrington,  Sir  E.,  case  of,  614. 

Coleridge,  S.  T.,  his  automatic  mental  ac- 
tivity, 586,  591  note,  617  note;  his  case 
of  recollection  of  ideas,  546  note. 

Collard  de  Martigny,  M.,  on  respiration  in 
nitrogen,  309  ;  on  pulmonary  exhalation, 
311. 

Collins,  Dr.,  on  infantile  mortality,  325. 

Colt,  Mr.,  on  the  pulse,  263  note. 

Combe,  Dr.  A.,  on  digestion,  113  note,  117; 
on  influence  of  passion  on  mammary 
secretion,  742  note ;  on  influence  of  mo- 
ther on  foetus,  782  ;  on  infant  nutrition, 
821  note. 

Combe,  Mr.  G.,  on  result  of  sexual  inter- 
course in  state  of  intoxication,  782  note. 

Combetti,  his  case  of  destruction  of  Cere- 
bellum, 517  note. 

Cooper,  Sir  A.,  his  experiments  on  coagu- 
lation of  blood  in  vessels,  211  ;  on  influ- 
ence of  emotions  on  mammary  secretion, 
742 ;  on  structure  of  mammary  gland, 
813-816;  on  thymus  gland,  163. 

Copland,  Dr.,  on  antiphlogistic  regimen,  85. 

Corfe,  Mr.,  on  water  at  Wolverton,  76  note. 

Cork,  Bishop  of,  his  case  of  lactation  by 
male,  817  note. 

Cord,  Marquis,  on  cochlear  nerve,  817. 

Coste,  M.,  on  decidua  reflexa,  767  note. 

Cowan,  Dr.,  his  case  of  consenual  move 
meuts,  503,  504 ;  of  apoplexy  of  Cere- 
bellum, 516  note. 

Cruveilhier.  M.,  his  case  of  ectopia  cordis, 
249 :  on  cirrhosis  of  liver,  375. 

Curling,  Mr.,  his  cases  of  hypertrophy  of 
the  fingers,  339  note ;  on  atrophy  of  bone, 
341,  342. 

Currie,  Dr.,  on  cutaneous  absorption,  147 

Cuvier,  on  the  hand,  33. 


874 


INDEX    OF    AUTHORS. 


D. 


Daltcn,  Dr.,  his  law  of  absorption  of  gases, 
303;  on  gastric  digestion,  118  note. 

Dalton,  Dr.  J.  C.,  on  corpus  luteum,  761, 
762  note;  on  starch  in  the  stomach,  103  ; 
on  pepsin,  109;  on  gastric  juice,  110. 

Dairy mple,  Mr.,  on  vasa  lutea  of  bird's 
egg,  789  note;  on  the  rapid  organization 
of  lymph  in  cachexia,  209  note. 

Daniell,  Dr.,  on  adynamic  fevers,  238  note; 
on  value  of  diaphoresis,  405  note;  on 
immunity  from  African  fevers,  834  note ; 
on  gradual  death  of  fever-patients,  865 
note. 

Davaine,  M.,  on  changes  of  form  of  colour, 
less  corpuscles,  180. 

Davis,  Dr.  N.  S.,  on  central  lobe  of  Cere- 
bellum, 521. 

Davy,  Dr.  J.,  on  venous  hue  of  arterial 
blood,  172 ;  on  effect  of  loss  of  blood, 
192;  on  gases  of  blood,  193;  on  non- 
coagulation  of  blood,  209,  211  ;  on  tem- 
perature of  human  body,  407,  409 ;  on 
absorbent  power  of  defibrinated  blood, 
177. 

Davy,  Sir  H.,  on  effect  of  gases  on  coagula- 
tion of  blood,  211. 

Day,  Prof.,  on  the  saliva,  104. 

Deleau,  M.,  on  vocal  sounds,  728. 

Delaroche  and  Berger,  MM.,  their  experi- 
ments on  endurance  of  heat,  411. 

De  Morgan,  Mr.,  on  removal  of  bone  by 
absorption,  335. 

Denis,  M.,  on  composition  of  blood,  189,  190. 

Desaguliers,  Dr.,  his  examples  of  muscular 
power,  715. 

Devergie,  M.,  on  presence  of  lead  in  muscle, 
230;  on  characters  of  embryo  at  different 
periods,  851,  852. 

Dibdin,  Rev.  R.  W.,  on  table-talking,  596. 

Dieffenbach,  Prof.,  on  transfusion  of  blood, 
216. 

Dixon,  Mr.,  on  nerves  of  taste,  465  note. 

Dobson,  Mr.,  his  experiments  on  the  spleen, 
168. 

Dodd,  Mr.,  his  case  of  early  viability,  776. 

Donders,  Prof.,  on  absorption  of  solid  par- 
ticles, 146. 

Donne,  M.,  on  temperature  in  disease,  409- 
416 ;  on  development  of  electricity  in 
living  body,  423 ;  on  human  milk,  820 
note. 

Donovan,  Dr.,  on  Irish  starvation,  84  note; 
on  evolution  of  light,  422. 

Dowler,  Dr.,  Bennet,  on  blood's  movement 
after  death,  270 ;  on  post-mortem  eleva- 
tion of  temperature,  410. 

Draper,  Prof.,  on  the  capillary  circulation, 
274 ;  on  mutual  diffusion  of  gases  in  re- 
ference to  respiration,  300. 

Duges,  M.  on  function  of  Cerebellum,  517; 
on  function  of  cochlea,  699. 

Dulong,  M.,  on  calorification,  415. 

Dunglison,  Prof.,  on  gastric  juice,  109;  on 
cutaneous  absorption,  149  note;  on  tem- 


perature in  disease,  409 ;  heat  of  uterus 
in  parturition,  412  note;  on  temperature 
of  paralysed  limbs,  416;  his  cases  of 
peculiar  secretion  of  milk,  816. 

Dunn,  Mr.,  his  eases  of  apoplexy  of  Cere- 
bellum, 516  note,  520;  of  suspended 
Cerebral  action,  638,  639  note. 

Dupuy,  M.,  on  injection  of  cerebral  sub- 
stance into  veins,  212. 

Dzondi,  on  deglutition,  90. 


E. 


Earle,  Mr.  H.,  on  temperature  of  paralysed 
limbs,  416. 

Earle,  Dr.  Pliny,  on  colour-blindness,  705 
note. 

Eberhard,  on  absorption  of  solid  particles, 
146. 

Ecker,  Prof.,  on  supra-renal  bodies,  162 
note;  on  pituitary  body,  165  note. 

Edwards,  Dr.  W.,  on  respiration  in  hydro- 
gen, 309  ;  on  temperature  of  infants,  407 
note ;  on  seasonal  variation  of  calorific 
power,  409 ;  on  influence  of  moist  air, 
412;  on  inferior  calorifying  power  of 
young  animals,  418,  419. 

Edwards,  Prof.  Milne,  on  infantile  mor- 
tality,' 420. 

Egerton,  Sir  Philip,  on  effect  of  castration 
on  buck,  228. 

Ehrenberg,  Prof.,  on  limits  of  vision,  674. 

Elliotson,  Dr.,  his  case  of  rapid  respiration, 
290. 

Emerson,  Dr.,  on  infantile  mortality,  420 
note. 

Enderlin,  on  gastric  juice,  109  note  ;  on  ash 
of  fteces,  131 ;  on  cholic  acid  in  blood, 
187  note;  379  note. 

Engelhardt,  on  columns  of  Spinal  Cord,  477. 

Erichsen,  Prof.,  on  rate  of  absorption,  141 ; 
on  asphyxia,  273  note,  316  note. 

Erman,  on  protracted  lactation,  821. 

Evanson,  D.,  his  case  of  abolition  of  sexual 
desire,  529  note. 


F. 


Fabre  and  Silbermann,  MM.,  on  heat  of 
combustion,  415. 

Faraday,  Prof.,  on  table-turning,  595  note; 
on  visual  illusions,  685,  686. 

Favre,  M.,  on  solid  matter  of  perspiration, 
402,  403. 

Fenwick,  Mr.,  his  experiments  on  absorp- 
tion by  lacteals,  134. 

Flourens,  M.,  on  reflex  action,  479;  on  re- 
moval of  Cerebrum,  496,  534  note ;  on 
functions  of  Corpora  Quadrigemina,  497  ; 
on  auditory  nerve,  494,  497 ;  on  effect  of 
section  of  thalami,  498 ;  on  Cerebellum, 
516:  on  effects  of  injuries  of  nervous 
system,  499  note;  on  effects  of  wounds 
of  acoustic  nerves,  501  note. 

Fodere  his  case  of  abstinence,  86. 


INDEX    OF    AUTHORS. 


875 


Ford,  Mr.,  his  case  of  absorption  in  ovarian 
dropsy,  148. 

Fordyce  and    Blagden,  Drs.,   their  experi- 
ments on  endurance  of  heat,  411. 

Fourcaul t,  Dr.,  on  cutaneous  asphyxia,  404. 

Foville,    M.,    on    functions    of  Cerebellum, 
517  ;  on  pathology  of  Insanity,  535. 

Fran£ois,  M.,  on  spontaneous  gangrene,  211 
note. 

Franklin,  Dr.,  on  learning  to  swim,  598. 

Franklin,  Sir  J.,  his  case  of  lactation  by 
male,  817  note. 

Frei,  on  blood-vessels  of  Peyerian  glands, 
152. 

Frerichs,  Prof.,  on  increase  of  urea  after 
ingestion  of  gelatin,  65 ;  on  composition 
of  saliva,  101  ;  on  action  of  saliva  in  the 
stomach,  103  ;  on  conversion  of  starch  in 
stomach,  117  ;  on  pancreatic  fluid,  121, 
123;  on  intestinal  digestion,  127;  on 
meconium,  380,  note;  on  structure  of 
kidney,  referred-to,  382,  note;  on  Bright's 
disease,  386,  388 ;  on  uraemia,  388  note, 

,     389,  note ;  on  composition  of  semen,  749. 

Frey,  Prof,  on  supra-renal  bodies,  162  note. 

Funke,  on  colourless  corpuscles  in  blood  of 
splenic  vein,  167. 


G. 

Gairdner,  Dr.  W.,  on  production  of  fibrin,  194. 
Gairdner,    Dr.   W.    T.,    on   contractility   of 
bronchial    tubes,    287 ;    on    structure   of 
kidney,  referred-to,  381  note. 
Gall,   on   amative  function   of  Cerebellum, 
517,  520  ;   on  comparative  development  of 
Cerebrum,  533. 

Gallwey,  Mr.  Brooke,  on  unhealthy  inflam- 
mations, 353,  note. 
Garrod,  Dr.,  on  saline  of  blood  in  cholera, 

205. 

Gelatin  Commissions,  reports  of,  64. 
Gasparin,  M.,  on  use  of  coffee,  79. 
Gerlach,  on  structure  of  kidney,  referred-to, 

381,  note,  384. 

Gilchrist,  Dr.,  on  water-dressing,  347,  note. 

Girdwood,  Mr.,  on  periodical  discharge  of 

•      ova,  757,  763,  note. 

Goodsir,  Prof.,  on  absorption  by  intestinal 

villi,   135,   136 ;  on  structure  of  kidney, 

referred-to,  381  note;  on  structure  of  de- 

cidua,  766-768  ;   on  villi  of  chorion,  768  : 

on  formation  of  placenta,  769;  on  cells  of 

milk-follicles,  815. 

Gorup-Bcsanez,    on   composition   of  blood, 

185. 

Graham,  Prof.,  on  gastric  juice,  109;  on 
osmotic  force,  137;  on  diffusibility  of  gum, 
145  ;  on  iron  in  blood-corpuscles  of  crabs, 
221 ;  his  law  of  mutual  diffusion  of  gases 
302. 

Grainger,  M.,  on  sanitary  state  of  Metropo- 
lis, 323  note ;  on  act  of  sucking,  87  ;  on 
irritation  and  division  of  afferent  nerves, 
479. 

Granville,  Dr.,  on  heat  of  uterus  in  parturi 
tion,  412,  note. 


3ray,  Mr.  H.,  on  structure  and  development 
of  spleen,  159,  161;  on  development  o» 
supra-renal  bodies,  163  ;  of  thyroid  body, 
165;  on  functions  of  spleen,  &c.,  166, 
168;  on  splenic  blood,  197,  198;  on  de- 
velopment of  eye  and  ear,  808. 

Green,  Dr.,  on  protracted  lactation,  821 
note. 

Greenhow,  Dr.,  on  treatment  of  burns,  347. 

Gregory,  Dr.,  his  case  of  suggested  dream- 
ing, 618,  note. 

Sruby  and  Delafond,  MM.,  on  rhythmical 
movements  of  intestinal  villi,  135;  on  epi- 
thelium-cells of  villi,  136  note. 

Gruenwaldt  and  Schroeder,  on  composition  oi 
gastric  fluid,  108,  109  note. 

Guillot,  M.,  on  structure  of  liver,  372  note; 
on  amount  of  milk  secreted,  823  note. 

Guislain,  M.,  on  insanity,  633  note;  on  in- 
fluence of  emotions  on  nutrition,  745. 

Gull,  Dr.,  on  uses  of  plexuses  of  nerves, 
443 ;  on  paralysis,  642  note,  648. 

Gulliver,  Mr.,  on  molecular  base  of  chyle, 
156 ;  on  red  corpuscles  of  blood,  175  note, 
000;  on  colourless  corpuscles,  178;  on 
coagulation  of  blood,  209,  211 ;  on  buffy 
coat,  214,  215;  on  molecular  base  of 
chyle,  155;  on  gorged  state  of  hepatic 
cells,  376. 

Gunther,  on  termination  of  nerve-fibres  in 
ganglia,  454  note. 

Guy,  Dr.,  on  the  rate  of  the  pulse,  256, 
257. 

Guyot,  M.,  on  treatment  of  wounds  by  hot 
air,  347. 


II. 


Haidlen,  on  composition  of  milk,  820  note. 

Hales,  on  the  force  of  heart's  contraction, 
255 ;  on  rate  of  blood's  movement  jn  ca- 
pillaries, 269. 

Hall,  Dr.  C.  Radclyffe,  on  contractility  of 
bronchial  tubes,  287  note;  on  vital  ca* 
pacity  of  lungs,  299 ;  on  decussation  of 
posterior  pyramids,  458 ;  on  ciliary  gan- 
glion, 462,  note. 

Hall,  Dr.  J.  C.,  on  protracted  gestation,  775 

Hall,  Dr.  M.,  his  Neurological  discoveries 
generally,  648  note;  on  deglutition,  91, 
93 ;  on  vomiting,  97 ;  on  action  of  sphinc- 
ters, 99 ;  on  circulation  in  acardiac  fce- 
tus,  271  note;  on  stimulus  to  respiratory 
movement,  291,  292  ;  on  reflex  action  of 
Spinal  Cord,  479,  482 ;  of  muscular  ten- 
sion, 487  ;  on  action  of  cantharides  on 
spinal  cord,  648 ;  on  emotional  actions, 
569 ;  on  epilepsy,  643  note ;  on  articulate 
sounds,  730  note;  on  stammering,  731. 

Haller,  on  quantity  of  blood  in  the  body, 
170;  on  respiratory  pulse,  276;  on  vica- 
rious secretion  of  urine,  364,  365 ;  on 
quantity  of  blood  sent  to  the  brain,  529 

Hamilton,  Dr.  Robt.,  case  of,  601,  602. 

Hamernjk,  on  sounds  of  heart,  253  note. 

Hannover,  Dr.,  on  exhalation  of  carbonio 
acid,  307. 


876 


INDEX    OF    AUTHORS. 


Harless,  on  columns  of  Spinal  Cord,  477. 

Harvey,  Dr.  Alex.,  on  relative  influence  of 
male  and  female  parents,  779  n«lf >;  on 
influence  of  foetal  blood  on  mfiternal,  782. 

Hastings.  Dr.,  on  capillary  circulation,  275; 
on  maintenance  of  heat  by  artificial  respi- 
ration, 415. 

Heyparth,  Dr.,  on  metallic  tractors,  746 
note. 

Heller,  on  urine  pigments,  394. 

Hecker,  Dr.,  on  epidemics  of  middle  ages, 
590  note. 

Henle",  Prof.,  on  sense  of  taste,  659;  on 
coagulation  of  fibrin,  219  note. 

Henry,  Dr.,  on  absorption  of  gases,  303. 

Henry,  Mr.  Mitchell,  his  case  of  deficient 
commissures,  529  note. 

Herapath,  Dr.  W.  B.,  on  lead-poisoning,  76. 

Herbst,  on  estimation  of  quantity  of  blood, 
170 ;  on  amount  of  air  respired,  299. 

Bering,  his  experiments  on  the  circulation, 
254,  263. 

Hertwig,  M.,  on  removal  of  Cerebrum,  496, 
534 ;  on  functions  of  corpora  quadrige- 
mina,  497;  on  Cerebellum,  515. 

Hewett,  Mr.  Prescott,  on  organization  of 
blood-clots,  208  note. 

Hewson,  on  red  corpuscles  of  blood,  173, 
175  ;  his  doctrine  of  lymphatic  absorption, 
156  note;  on  production  of  red  corpuscles 
in  spleen  and  thymus,  167;  on  coagula- 
tion of  blood,  207 ;  on  effect  of  urine  on 
blood,  177. 

Hibbert,  Dr.,  on  apparitions,  635. 

Hill,  Dr.,  his  case  of  cutaneous  absorption, 
148. 

Hofacker,  M.,  on  proportion  of  sexes,  809. 

Hoffmann,  on  action  of  bile  on  digestion, 
125. 

Holland,  Dr.  G.  C.,  on  temperature  of  in- 
fants, 407. 

Holland,  Dr.  H.,  on  memory,  582;  on  vol- 
untary recollection,  588  note;  on  sleep, 
612 ;  on  general  Physiology  of  Nervous 
system,  referred-to,  648  note ;  on  produc- 
tion of  subjective  sensations  by  attention, 
552;  on  instinctive  choice  of  food,  &c., 
664  note  ;  on  influence  of  expectant  atten- 
tion on  involuntary  movements,  738 ;  on 
hereditary  diseases,  780  note. 

Holmes,  Mr.  E.,  his  life  of  Mozart,  referred- 
to,  290  note. 

Home,  Dr.  F.,  on  temperature  in  disease, 
409. 

Hooker,  Dr.,  on  relation  between  pulse  and 
respiration,  290  note. 

Houston,  Dr.,  on  circulation  in  acardiac  foe- 
tus, 271  note. 

Howe,  Dr.,  on  case  of  Laura  Bridgman,  44  ; 
on  emotional  excitement,  570  note;  on 
idiocy,  574  note,  780  note. 

Hubbenet,  on  gastric  juice,  108,  109  note, 
114  note;  on  pancreatic  fluid,  121. 

Hunefeld,  on  action  of  bile,  &c.,  on  blood 
corpuscles,  177. 

Huguier,  M.,  on  Duveruey's  glands,  758 
note. 


Humboldt,  Baron,  his  case  of  lactation  b> 
male,  817  note. 

Hunter,  John,  on  coagulation  of  blood,  208  : 
209;  on  assumption  of  male  plumage  by 
female  pheasant,  228;  his  doctrine  of 
lymphatic  absorption,  149;  on  muscular 
contractility  of  arteries,  259,  261 ;  on 
hypertrophy  from  augmented  supply  of 
blood,  338 ;  on  healing  processes,  345, 
348;  his  case  of  paraplegia,  481  note;  on 
oblique  muscles  of  eye,  710;  on  vesiculse 
seminales,  749  ;  on  blood-vessels  in  spon- 
taneous gangrene,  211  note. 

Hunter,  Dr.  W.,  on  Decidua  reflexa,  767. 

Huss,  Dr.,  on  Alcoholismus  chronicus,  78, 
336  note. 

Hutchinson,  Col.,  on  ancon  breed  of  sheep, 
832  note. 

Hutchinson.  Dr.  J.,  on  elastic  tension  of 
lungs,  287 ;  on  action  of  intercostal  mus- 
cles, 289 ;  on  forces  of  inspiration  and 
expiration,  289,  290  ;  on  number  of  respi- 
tions,  290 ;  on  vital  capacity  of  chest, 
298;  its  relation  to  height  and  weight, 
298,  299 ;  on  amount  of  air  inspired, 
300 ;  on  limit  of  suspension  of  respiratory 
movements,  314  note. 

Hutchinson,  Dr.,  his  case  of  lost  sense  of 
smell,  664  note;  on  change  of  colour  in 
Negro,  825  note. 

Huxley.  Mr.  T.  H.,  on  structure  of  spleen, 
159,  161;  on  toxic  inflammations,  237; 
on  function  of  liver,  376  note;  on  tactile 
papillae,  653. 


Hiring,  on  composition  of  faeces,  130  note. 
Inman,  Dr.,  on  partial  bleaching  of  Negro's 
skin,  825  note. 

J. 

Jackson,  Dr.  S.,  on  vital  capacity  of  lungs, 
289  note ;  on  gradual  death  in  adynamic 
fevers,  865  note;  on  function  of  semi- 
circular canals,  699  ;  on  pancreatic  fluid, 
122-124. 

Jacubowitcsh  on  saliva,  101,  103. 

Jardina,  Rev.  Fergus,  case  of,  776  note. 

Jeffreys,  Mr.  J.,  on  inspired  air,  300. 

Johnson,  Dr.  G.,  on  structure  of  kidney, 
referred-to,  382  note  ;  on  oblique  muscles 
of  eye,  710,  711. 

Johnstone,  Dr.,  on  conversation  of  deaf  and 
dumb,  727. 

Jolly  on  endosmotic  equivalent  of  gum,  145. 

Jones,  Dr.  Bence,  on  water  in  blood,  192; 
on  action  of  saliva  in  stomach,  104 ;  on 
gastric  juice,  109,  110  note ;  on  emulsifi- 
cation,  by  bile,  125  note;  on  interchange 
of  gases  in  respiration,  304 ;  on  produc- 
tion of  nitric  acid  in  the  body,  396;  on 
sulphates  in  urine,  395 ,  on  phosphate 
in  urine,  395:  on  acidity  of  urine,  393, 
396 ;  on  alkalescence  of  urine,  397 ;  on 
base  of  uric-acid  deposits,  395  note. 

Jones,  Dr.  Handfield,  on  fatty  degeneration, 
335  note;  on  fibroid  degeneration,  340 


INDEX    OF    AUTHORS. 


877 


note,  354  note;  on  structure  of  liver,  372  ; 
on  biliary  cells,  377  note. 

Tones,  Mr.  Joseph,  on  endosmose,  139. 

/ones,  Mr.  Wharton,  on  red  corpuscles  of 
blood,  174;  on  colourless  corpuscles,  179; 
on  gradation  of  forms  of  blood-corpuscles, 
184;  on  buffy  coat,  214;  on  rhythmical 
movements  of  veins  in  bat's  wing,  158, 
note;  on  structure  of  spleen,  159-161  ; 
on  effects  of  stimuli  on  the  smaller  arte- 
ries, 259 ;  on  retardation  of  capillary 
circulation  by  stream  of  carbonic  acid. 
273;  on  structure  of  liver,  371  note. 

Juriu,  Dr.,  on  absorption  of  vapour,  148. 


Raster,  on  luminosity  of  perspiration,  422. 

Kellie,  Dr.,  on  the  inter-cranial  circulation, 
278. 

Kemp,  see  Schlossberger. 

Kempelen,  on  vowel  sounds,  728,  729. 

Kiernan,  Mr.,  on  structure  of  liver,  369- 
874. 

Kilian,  on  fatty  degeneration  of  uterus  after 
parturition,  335. 

King,  Mr.  T.  W.,  on  tricuspid  valve,  251. 

Kirkes  and  Paget,  on  passage  of  Cerebro- 
spimil  fibres  through  sympathetic  ganglia, 
737  note;  on  endosmose,  138  note;  on 
state  of  ventricles  after  contraction,  253 
note;  on  contraction  of  bronchial  muscu- 
lar fibre,  300. 

Kitto,  Dr.,  on  guiding  sensations,  506  ;  on 
automatic  action  of  mind  in  children,  576, 
note;  his  cases  of  acute  tactile  sensibility, 
658  note. 

Kiwisch,  on  sounds  of  heart,  253  note. 

Knox,  Dr.,  on  the  diurnal  variation  of  the 
pulse,  257. 

Kobelt,  Dr.,  on  Fallopian  tubes  and  Wolffian 
bodies,  799  note. 

Kolliker,  Prof.,  on  structure  of  gastric  fol- 
licles, 107 ;  on  muscular  structure  of  in- 
testinal villi,  135;  on  epithelium  cells  of 
intestinal  villi,  136,  note;  on  structure 
of  Peyerian  glands,  152;  on  absorbent 
glands,  153 ;  on  contractions  of  lympha- 
tics, 158;  on  structure  of  spleen,  159, 160; 
on  supra-renal  bodies,  162;  on  thymus, 
163,  164;  on  use  of  spleen,  168  note;  on 
proportion  of  colourless  corpuscles  to  red, 
180;  on  binary  subdivision  of  red  cor- 
puscles, 182 ;  on  effects  of  loss  of  blood, 
192;  on  structure  of  arterial  walls,  258: 
on  diameter  of  capillaries,  267  ;  on  veins, 
275  note ;  on  erectile  tissue,  279 ;  on 
muscular  fibres  of  bronchial  tubes,  284 ; 
on'air-cells  of  lungs,  285;  on  structure 
of  liver,  371,  372  note;  on  structure  of 
kidney,  381  note;  on  structure  of  spinal 
cord,  448-455 ;  on  connection  of  corpora 
striati  and  thalami  optici  with  Cerebrum, 
490  note;  on  structure  of  cortical  sub- 
stance of  Cerebrum,  524  note;  on  tactile 
papillae,  653,  654 ;  on  structure  of  retina, 
571-672 ;  on  structure  of  iris,  675  ;  on 


cochlear  nerve,  692  note;  on  spermatozoa, 
750;  on  corpus  luteum,  759  note;  on 
augmentation  of  uterine  substance  iu 
pregnsincy,  772;  on  embryonic  develop- 
ment of  Entozoa,  785  note. 

Krahmer,  Prof.,  on  action  of  diuretics,  401. 

Krause,  on  intestinal  villi,  134;  on  intes- 
tinal glandulae,  153  note. 

Kronenberg,  Dr.,  on  roots  of  spinal  nerves, 

Kunde,  on  secretion  of  bile,  379. 

Kviss,  on  epithelium-cells  of  villi,  136  note. 


Lacauchie.  M.,  on  contractility  of  intestinal 
villi,  135. 

Laennec,  on  sounds  of  heart,  252 ;  on  ch> 
rhosed  liver,  375. 

Lafargue,  M.,  on  lesion  of  Thalami  Optici, 
498 ;  on  Corpora  Striata,  499 ;  on  Cere- 
bellum, 515. 

Lallemand,  M.,  on  morbid  sympathies,  629 
note. 

Lane,  Mr.  S.,  on  red  corpuscles  of  blood, 
173  note. 

Landerer,  Dr.,  on  urea  in  sweat,  403. 

Larrey,  Baron,  on  Syro- Arabian  race,  839. 

Latham.  Dr.,  on  scurvy  at  Milbarik,  85  note. 

Latham,  Dr.  R.  G.,  on  varieties  of  Men, 
825  note ;  on  Negro  area,  827  note ;  on 
Indo-Germanic  race,  838;  on  Syro- Ara- 
bian race,  839 ;  on  population  of  India, 
841 ;  on  Kaffre  language,  844 ;  on  popu- 
lation of  Oceania,  848. 

Lay  cock,  Dr.,  on  vicarious  secretion  of 
urine,  364 ;  on  reflex  function  of  brain, 
543  note,  604  note ;  on  morbid  sympathies, 
629 ;  on  connection  of  gout  and  hysteria, 
646  note. 

Lebret,  Dr.,  his  case  of  turning  and  rolling, 
caused  by  wound  of  encephalon,  501  note. 

Lecanu,  M.,  on  composition  of  blood,  189, 
190  ;  on  water  of  blood  in  cholera,  205, 
on  fat  in  blood,  204 ;  on  carbon  in  drunk- 
ards' blood,  336  note;  on  excretion  of  urea, 
391. 

Lee,  Dr.  R.,  on  periodical  discharge  of  ovs*, 
757. 

Lee,  Mr.  H.,  on  the  effect  of  admixture  of 
pus  with  blood,  212. 

Lee,  Mr.  W.,  on  preventible  disease,  32<> 

Legallois,  M.,  on  dependence  of  hearts 
action  on  spinal  cord,  242 ;  on  animal 
heat,  416. 

Lehmann,  Prof.,  on  composition  .of  blood, 
176,  186,  187;  on  absorbent  power  of 
defibrinated  blood,  177;  on  solution  of 
blood-corpuscles,  178;  on  composition  of 
extractive,  187  ;  on  blood  of  hepatic  vein, 
198;  on  alkaline  salts  of  blood,  205;  on 
saliva,  101-104;  on  gastric  juice,  108,  109; 
on  pancreatic  fluid,  122,  123;  on  quan- 
tity of  blood,  171  ;  on  production  of  car- 
bonic acid,  303—305 ;  on  composition  of 
bile,  377 ;  on  formation  of  bile,  379 ;  on 
composition  of  urine,  390  note  ;  on  varia- 


878 


INDEX    OF    AUTHORS. 


tions  in  proportions  of  its  components, 
391,  397,  398  ;  on  its  acid  reaction,  396 
note;  on  gastric  juice.  109;  on  gases  of 
blood,  193 ;  on  quantity  of  bile  secreted, 
126,  note;  on  succus  entericus,  127;  on 
absorption,  143-145:  on  origin  of  albu- 
men and  fibrin  in  chyle,  218  note;  on 
consumption  of  oxygen,  363  note ;  on  in- 
fluence of  diet  on  urine,  397,  398. 

Lehmann,  Dr.  Julius,  on  influence  of  coffee, 
399. 

Leidy,  Dr.,  on  structure  of  liver,  '367  note, 
372  note. 

Lenz,  M.,  on  intestinal  digestion,  122. 

Lepine,  M.,  on  act  of  vomiting,  96. 

Letellier,  M.,  on  influence  of  external  tem- 
perature on  production  of  carbonic  acid, 
304. 

Letheby,  Dr..  on  elimination  of  narcotic 
poisons,  232 ;  on  discharge  of  ovules  in 
menstruation,  757  note. 

Leuchs,  on  transforming  powers  of  saliva, 
104  note. 

Leuckardt,  Dr.,  on  spermatozoa,  751  note; 
on  vesicula  prostatica,  801  note. 

Leuret,  M  ,  on  comparative  anatomy  of 
Cerebellum,  513  note;  on  comparative 
size  of  Cerebellum  in  geldings,  &c,  518, 
519;  on  average  size  of  encephalon, 
529. 

Leuret  and  Mitivie,  MM.,  on  pulse  of  old 
persons,  256  note. 

Ley,  Dr.  H.,  his  case  of  disordered  respira- 
tion, 293. 

Leydig,  Dr.,  on  structure  of  spleen,  159- 
161  ;  on  supra-renal  bodies,  162  note. 

Liebig,  Prof.,  on  fibrin  of  blood  and  muscle, 
216;  on  calorific  powers  of  diiferent 
articles  of  food,  66 ;  on  slightly  decom- 
posed food,  74 ;  on  nature  of  faecal  mat- 
ters, 132  ;  on  purgative  action  of  saline 
solutions,  148  note;  on  amount  of  carbon 
excreted,  308 ;  on  source  of  secretions, 
360;  on  relation  of  composition  of  bile 
and  urine  to  that  of  flesh,  378  note;  on 
chemical  theory  of  calorification,  417. 

Liebig,  Dr.  G.,  on  exhalation  of  carbonic 
acid  from  muscle,  281. 

Lining,  on  absorption  of  vapour,  148. 

Lister,  Mr.  J.  J.,  on  structure  of  iris,  675 
note. 

Locke,  John,  on  force,  542  note. 

Longet,  M.,  on  movements  of  stomach,  96; 
on  contractility  of  bronchial  tubes,  286 ; 
|  on  columns  of  Spinal  Cord,  473,  474 ; 
on  roots  of  pneumogastric,  466 ;  on  re- 
moval of  Cerebrum,  496 ;  on  functions  of 
corpora  quadrigemina,  497 ;  on  thalami 
optici,  498 ;  on  corpora  striata,  499 ;  on 
crura  oerebri,  499  note,  502 ;  on  Cere- 
bellum, 515-516 ;  on  division  of  fifth  pair, 
744. 

Lonsdale,  Dr.,  on  departure  of  odour  of 
prussic  acid,  231. 

Ludwig,  Prof.,  on  influence  of  nerves  upon 
secretion  of  saliva,  739,  740. 

Lyons,  Dr.,  on  Histolysis,  335  note. 


Macartney,  Prof.,  on  the  healing  processes, 
344,  345;  on  treatment  of  wounds  by 
steam,  346. 

Macgregor,  Mr.,  on  increase  of  expiration 
of  carbonic  acid  in  diseases  of  skin,  307. 

Mackinnon,  Dr.,  on  Tropical  Hygiene,  324 
note. 

Maclean,  Mr.  on  St.  Kilda,  325. 

M' William,  Dr.,  on  artificial  lactation,  816. 

Madden,  Dr.  W.  H.,  on  cutaneous  absorp- 
tion, 147,  148;  on  pulmonary  absorp- 
tion, 312  ;  on  tuberctilosis,  356  note. 

Madden,  Dr.  Henry,  on  the  magnetometer, 
592  note. 

Magendie,  M.,  on  sugar  in  the  blood,  151 
note;  on  sanguification,  151;  on  transu- 
dation  of  blood,  202 ;  on  deglutition,  90 ; 
on  act  of  vomiting,  96 ;  on  action  of  sto- 
mach during  vomiting,  96  ;  on  saliva,  102  ; 
on  rate  of  absorption  from  alimentary 
canal,  142;  on  diminution  of  fibrin  in 
blood,  202;  on  roots  of  spinal  nerves, 
402 ;  on  removal  of  Cerebrum,  496 ;  on 
effects  of  injuries  of  nervous  system, 

499  note ;   on   corpora   striata,  499 ;    on 
results  of  wounds  of  medulla  oblongata, 

500  note ;  on  Cerebellum,  515 ;  on  cerebro 
spinal  fluid,  530 ;  on  falsetto  voice,  725  ; 
on  division  of  fifth  pair,  744. 

Magnus,  Prof,  on  absorbent  power  of  defi- 
brinated  blood,  177 ;  on  gases  of  blood, 
193. 

Malacorps,  M.,  on  removal  of  Cerebrum, 
496. 

Malcolm,  Mr.,  on  diminution  of  excretion  of 
carbonic  acid  in  typhus,  307. 

Mara,  Mad.,  her  compass  of  voice,  716  note. 

Marc,  M.,  his  case  of  suspended  animation, 
314  note. 

Marcet,  Dr.,  on  composition  of  faeces,  131; 
on  fat  in  the  blood,  204. 

Marchand,  M.,  on  influence  of  diet  on  blood, 
192;  his  analysis  of  urine,  391. 

Marsh,  Sir  H.,  on  evolution  of  light,  421, 
422. 

Marshall,  Mr.,  on  development  of  veins, 
888  note. 

Martineau,  Miss,  on  materialism,  538  note; 
her  cases  of  idiocy,  582  note,  606  note. 

Martin,  Magron,  on  effects  of  injuries  of 
nervous  system,  500  note. 

Matteucci,  Prof.,  on  endosmose  and  exos- 
mose,  138 ;  on  endosmosis  of  fatty  mat- 
ters, 143  ;  on  disturbance  of  electric  equi- 
librium in  organic  processes,  423 ;  on 
muscular  current,  423 ;  on  development 
of  electricity  by  muscular  contraction, 
425. 

Mayer,  Dr.,  on  vicarious  secretion  of  urine, 
364. 

Mayhew,  Mr.  Henry,  on  acuteness  of  hear- 
ing in  blind,  702  note;  on  nomadic  races, 
830  note. 

Mayo,  Mr.  H.,  on  optic  chiasma,  493;  on 
guiding  sensations,  507 ;  on  rhythmical 


INDEX    OF    AUTHORS 


879 


oscillations,    592   note;    on   the  divining 
rod,  593  note :  on  falsetto  voice,  725. 

Me"he"e  de  la  Touche,  on  effects  of  injuries 
of  nervous  system,  499. 

Mendelssohn,  on  mechanism  of  respiration, 
298  note. 

Mensonides,  on  absorption  of  solid  particles, 
146. 

Mialhe,  M.,  on  albuminose,  196;  on  salivary 
secretion,  101  note. 

Mill,  Mr.  James,  on  ideation,  536  note. 

Mr.  John,  on  explanation  of  pheno- 
mena, 245  note;  his  logic  of  the  moral 
sciences,  538  note, 

Miller,  Prof.,  on  quantity  of  diseases,  230 
note. 

Mitchell,  Dr.,  on  heart  of  sturgeon,  241 ; 
on  continuance  of  heart's  action  in  vacua, 
242  note. 

Moleschott,  on  proportion  of  colourless  cor- 
puscles to  red,  180 ;  on  size  of  pulmonary 
air-cells,  285  note  ;  on  formation  of  bile, 
379. 

Montgomery,  Dr.,  on  placental  bruit,  771 ; 
on  duration  of  pregnancy,  777  note ;  on 
influence  of  mother  on  foetus,  783  note. 

Moore,  Mr.,  on  casein  of  human  milk,  819. 

Moreau,  M.,  on  hachisch,  540,  618  note, 
626. 

Morell,  Mr.,  on  relation  of  mind  and  mat- 
ter, 544  note;  on  perceptive  and  intui- 
tional consciousness,  554-559 ;  on  lan- 
guage, 562. 

Morgan,  Mr.,  on  mammary  foetus  of  kan- 
garoo, 87  note. 

Morgante,  on  motor  roots  of  pneumogastric, 
466. 

Morningside  Lunatic  Asylum,  Report  of, 
referred-to,  631  note,  632  note. 

Mozart,  his  intuitive  and  automatic  mental 
activity  referred-to,  557,  note,  586,  587. 

Miiller,  Prof.,  on  absorption  by  cutaneous 
lymphatics,  149  ;  on  coagulation  of  the 
blood,  207 ;  on  erectile  tissue,  279 ;  on 
respiration  in  hydrogen,  309  ;  on  roots 
of  spinal  nerves,  442  ;  on  laws  of  nervous 
transmission,  443,  449 ;  on  motor  roots 
of  pneumogastric,  466 ;  on  Cerebellum, 
on  attention  to  sensory  impressions,  547  ; 
on  complementary  colours,  686 ;  on 
acoustic  principles  of  hearing,  693 ; 
on  length  of  vocal  cords,  716;  his  re- 
searches on  voice,  721-725  ;  on  stammer- 
ing, 732 ;  on  venous  system  of  fishes,  793 
note. 

Miiller,  Dr.  H.,  on  structure  of  retina, 
672. 

Miiller,  on  secretion  of  gastric  juice,  115; 
on  influence  of  water  on  red  corpuscles, 
177;  his  defence  of  Bernard's  theory 
concerning  pancreatic  fluid,  123  ;  on  ab- 
sorption, 138;  on  structure  of  liver, 
369. 

Murphy,  Prof,  his  cases  of  protracted  ges- 
tation, 778  note. 


N. 


Nairne,  Dr.,  his  case  of  softening  of  Spinal 
cord,  474  note. 

Nasse,  Prof.,  on  specific  gravity  of  blood, 
172;  on  absorbent  power  of  defibrinated 
blood,  177  ;  on  buffy  coat,  214 ;  on  effects 
of  starvation  on  fibrin,  218  note;  on 
colourless  corpuscles,  222  ;  on  composi- 
tion of  chyle,  155;  on  influence  of  food 
on  secretion  of  liver,  380. 

Neill,  Dr.  Jno.,  on  condyloid  processes  of  the 
occiput,  35,  36  ;  on  structure  of  mucous 
membrane  of  stomach,  107  note. 

Newport,  Mr.,  on  blood  corpuscles  of  in- 
sects, 221,  222  ;  on  increase  of  carbonic 
acid  excreted,  by  exercise,  306 ;  on  nerv. 
ous  ganglia  of  Articulata,  454;  on  ferti- 
lizing power  of  spermatorca.  751  note, 
764 ;  on  changes  in  germinal  vesicle,  764 ; 
on  embryonic  development  cf  Batrachia. 
785  note. 

Newton,  Sir  Isaac,  on  ocular  spectra,  641. 

Nicolai,  his  spectral  illusions,  641. 

Noble,  Dr.,  his  cases  of  paralysis  of  fifth 
pair,  465 ;  his  case  of  paralysis  of  voli- 
tion, 635  note. 

Norris,  Mr.,  on  Syro- Arabian  race,  839; 
on  population  of  India,  841 ;  on  Hot- 
tentot language,  844  note;  on  Australian 
language,  848. 

Nysten,  on  excretion  of  carbonic  acid,  307 ; 
on  vicarious  secretion  of  urine,  364,  365. 

0 

Oesterlen,  on  absorption  of  solid  particles, 
146. 

Oldham,  Dr.,  on  period  of  conception,  763 
note. 

Ollivier,  M.,  on  pathology  of  Spiral  Cord, 
520  note. 

Oppenheim,  Dr.,  his  case  of  imitative  sui- 
cide, 632  note. 

Orton,  Mr.,  on  physiology  of  breeding,  779 
note. 

Outrepont,  Dr.,  his  case  of  early  viability; 
777. 

Owen,  Prof.,  on  Anthropoid  Apes,  40-42; 
on  salivary  glands  of  Myrmecophaga,  102 
note ;  on  typical  vertebra,  803,  804 ;  on 
cranial  vertebrae,  472,  804,  805 ;  on  Mau- 
champ  breed  of  sheep.  832  note. 

P. 

Paget,  Mr.,  on  red  corpuscles  of  blood, 
174 ;  on  development  of  blood-corpuscles, 
181-183;  on  fibrin  of  abnormal  blood, 
199;  on  organization  of  blood-clot,  208; 
on  retarded  coagulation  of  blood,  210;  on 
colourless  corpuscles,  222 ;  on  symmetri- 
cal diseases,  226,  227  ;  on  complementary 
nutrition,  228 ;  on  local  determining 
causes  of  inflammation,  237 ;  on  propa- 
gation of  contractile  movements  of  heart. 


880 


INDEX    OF    AUTHORS. 


241 ;  on  complete  contraction  of  heart, 
253 ;  on  effects  of  mechanical  irritation 
on  smaller  arteries,  259  note ;  on  capil- 
lary circulation,  273  note,  274 ;  on  forma- 
tive power  of  individual  parts,  332,  333; 
on  fatty  degeneration  of  lymph,  335,  336; 
on  exuviation  of  dead  parts,  337 ;  on 
tumours,  340 ;  on  reparative  power,  343, 
344 ;  on  incipient  changes  in  atrophy, 
348  ;  on  healing  processes,  345-348 ;  on 
inflammation,  350-357 ;  on  localization 
of  inflammatory  action,  350 ;  on  heat  of 
inflammation,  351  ;  on  lymph-products  of 
inflammation,  353,  354 ;  on  tuberculosis, 
356  note;  on  cancerous  cachexia,  328 
note,  357  note ;  on  fatty  liver,  375 ;  his 
case  of  deficient  commissures,  528  note ; 
on  influence  of  nervous  system  on  nutri- 
tion, 744. 

Paget,  Dr.,  on  morbid  rhythmical  move- 
ments, 516  note. 

Pancoast,  Dr.,  on  operation  for  strabismus, 
714  note. 

Panizza,  on  crural  plexus  of  Frog,  443. 

Panum,  Dr.,  on  sanitary  condition  of  Faroe 
islands,  75. 

Popp,  on  composition  of  blood  in  disease, 
199. 

Parent-Duchatelet,  M.,  on  inhalation  of  sul- 
phuretted hydrogen,  312. 

Parker,  Mr.  Langston,  on  mercurial  inhala- 
tion, 313  note. 

Parkes,  Dr.,  on  influence  of  liq.  potassse  on 
solids  of  urine,  400. 

Peaslee,  Dr.,  on  foetal  circulation,  795  note. 

Peligot,  on  effect  of  nitrogen  on  protosalts 
of  iron,  195  note. 

Pennock,  Dr.,  on  pulse  of  old  persons,  256 
note. 

Percy,  Baron,  on  siege  of  Landau,  782. 

Percy,  Dr.,  on  absorption  of  alcohol,  142. 

Pereira,  Dr.,  on  Food  and  Diet,  referred  to, 
73  note,  77  note;  on  nutritious  properties 
of  gum,  145  note. 

Peddie,  Dr.,  on  mammary  secretion,  816 
note. 

Pe"trequin,  M.,  on  function  of  Cerebellum, 
521 ;  on  falsetto  voice,  726. 

Philip,  Dr.  Wilson,  on  secretion  of  gastric 
juice,  115;  on  independent  action  of 
heart,  242  ;  on  capillary  circulation,  275  ; 
on  maintenance  of  animal  heat  by  artifi- 
cial respiration,  415. 

Pinel-Grandchamp,  M.,  on  function  of 
Cerebellum,  517. 

Playfair,  Dr.  L.,  on  composition  of  milk, 
820. 

I'oggiale,  on  composition  of  blood,  189. 

Poisseuille,  M.,  his  experiments  on  influ- 
ence of  viscidity  on  capillary  flow,  206; 
on  the  rate  of  circulation,  254 ;  on  force 
of  heart's  contraction,  255 ;  on  muscular 
contractility  of  arteries,  260  ;  on  lateral 
pressure  of  blood  within  arteries,  265. 

Polli.  Dr.,  on  effect  of  loss  of  blood,  192  ; 
on  coagulation  of  blood,  209-211. 

Pouchet,  M.,  on  ovulation,  759  note. 


Pourfour  du  Pettit,  on  results  of  wounds  of 
nervous  system,  499  note. 

Praeter,  Mr.,  on  substances  affecting  co- 
agulation of  blood,  210. 

Prevost  and  Dumas,  MM.,  on  mode  of  ana- 
lysis of  blood,  185  note;  on  fertilizing 
power  of  spermatozoa,  751  note. 

Prichard,  Dr.,  on  Varieties  of  Man,  825 
note  ;  on  typical  forms  of  skull,  827-829  ; 
on  changes  in  domesticated  animals,  833 
note  ;  on  psychical  conformity  of  humnn 
races,  835  ;  on  Celtic  languages,  837  ;  on 
somatic  death,  865  note. 

Prochaska,  on  reflex  action,  479  ;  on  the 
general  Physiology  of  the  Nervous  sys- 
tem, referred-to,  648  note. 

Prout,  Dr.,  his  classification  of  alimentary 
substances,  63,  64  note;  on  conversion 
of  starch  into  albumen,  146  ;  on  secondary 
digestion,  150;  on  excretion  of  carbonic 
acid,  306 ;  on  quantity  of  urine,  390 ;  on 
its  specific  gravity,  390. 

Purkinje,  Prof.,  optical  experiment  of,  689. 

Q. 

Quekett,  Mr.  J.,  on  elastic  tissue  in  faeces, 
130  note. 

Quetelet,  M.,  on  influence  of  seasons  on 
mortality,  419  ;  on  length  and  weight  of 
new-born  infants,  810;  on  viability  of 
male  and  female,  811,  812;  on  relative 
heights  and  weights  of  male  and  female 
at  different  ages,  812. 

R. 

Raciborski,  M.,  on  periodical  discharge  of 
ova,  757. 

Radcliffe,  Dr.  C.  B.,  on  automatic  mental 
action  in  children,  576  note. 

Rainey,  Mr.  G.,  on  structure  of  lungs,  284 
note. 

Rathke,  Dr.,  on  development  of  venous  sys- 
tem, 793. 

Rawitz,  Dr.,  on  components  of  faeces,  130. 

Redfern,  Dr.,  on  atrophy  of  cartilage,  342. 

Rees,  Dr.  G.  0.,  on  red  corpuscles  of  blood, 
173  ;  on  phosphorized  fats  of  blood,  193  ; 
on  composition  of  chyle  and  lymph,  155; 
on  phosphorus  in  blood,  193  :  on  urea  in 
blood,  388  note ;  on  composition  of  milk, 
821. 

Registrar-General's  Report,  on  influence  of 
cold  on  mortality,  420,  864  note. 

Regnault  and  Reiset,  MM.,  on  production 
of  carbonic  acid  in  respiration,  303,  304, 
306 ;  on  absorption  and  exhalation  of 
nitrogen,  310. 

Reich,  on  phosphorized  fats  of  blood,  193. 

Reichenbach,  Baron,  on  odyle,  623. 

Reid,  Dr.  John,  on  sense  of  hunger,  81 ;  on 
nerves  of  deglutition,  91,  92;  on  move- 
ments of  stomach,  95  ;  on  restoration  of 
digestion  after  section  of  pneumogastrics, 
96 ;  on  influence  of  nerves  on  secretion. 
114-116;  on  heart's  action  in  vacuo, 


INDEX    OF    AUTHORS. 


881 


241 ;  on  excitement  of  heart's  contrac- 
tions through  nerves,  243,  244  ;  on  effects 
of  stoppage  of  respiration  on  hema- 
dynamatic,  247  note;  on  re-excitement 
of  heart's  action  by  relief  of  distension, 
251  ;  on  retardation  of  systemic  circu- 
lation in  asphyxia,  273 ;  on  function  of 
pneumogastric  in  respiration,  291  ;  on 
laryngeal  nerves,  294,  295 ;  on  results 
of  section  of  pneumogastrics,  296,  297  ; 
on  asphyxia,  315;  his  case  of  hypertro- 
phy of  a  limb,  339  note  ;  on  atrophy  from 
disuse,  348  ;  on  structure  of  medulla  ob- 
longata,  456 ;  on  functions  of  glosso- 
pharyngeal,  465,  466  ;  on  nerves  of  taste, 
465,  466 ;  on  motor  roots  of  pneumo- 
gastric, 466  ;  on  spinal  accessory,  469 ; 
on  structure  and  connections  of  placenta, 
769 ;  on  Eustachian  valve,  795. 

Reil,  on  nerves  of  internal  senses,  525, 
536. 

Reinhardt,  on  Graafian  vesicle,  754  note; 
on  colostric  corpuscles,  818. 

Reiset,  M.,  on  respiration,  see  Regnault. 

Remak,  Dr.,  on  structure  of  spleen,  159- 
161. 

Retzius,  Dr.,  on  fat  in  urine  after  parturi- 
tion, 774  note. 

Retzius,  Prof.,  on  structure  of  liver,  372; 
on  variations  in  position  of  Cerebellum, 
518  note;  on  development  of  Cerebrum, 
808  note. 

Reynolds,  Dr.  J.  R.,  on  vertigo,  642  note. 

Richardson,  Sir  J.,  on  arctic  diet,  88  note; 
on  endurance  of  cold,  411  note, 

Ridard,  M.,  on  influence  of  emotions  on 
nutrition,  745,  746. 

Ritchie,  Dr.,  on  evolution  of  ova,  755. 

Roberton,  Mr.,  on  menstruation,  775  note. 

Robertson,  Dr.,  on  diet  and  regimen,  73 
note. 

Roberts,  Mr.,  his  apparatus  for  reading 
card  in  rapid  motion,  685  note. 

Robin,  M.,  on  the  blood,  152;  on  decidua, 
767  note. 

Robin  and  Verdiel  on  pepsin,  109. 

Robinson,  Mr.,  on  effusion  of  fibrin,  352  ; 
on  albuminous  urine,  387  note. 

Rochoux,  M.,  on  pulmonary  air-cells,  285. 

Roger,  M.,  on  temperature  of  infants,  407, 
409. 

Rokitansky,  Prof.,  on  fatty  degeneration, 
336  note;  on  inflammatory  deposits,  353. 

Rolando,  M.,  his  experiments  on  respira- 
tion, 312;  on  Cerebellum,  514. 

Ronberg,  Dr.,  on  nerves  of  taste,  465  note. 

Ronalds,  Prof.,  on  sulphur  and  phosphorus 
in  urine,  394. 

Rosenthal,  on  Medulla  Oblongata,  456. 

Rossignol,  M.,  on  pulmonary  structure,  285, 
286. 

Rostan,  M.,  on  starvation,  84  note. 

Routh,  Dr.,  on  puerperal  fever  of  Vienna, 
233  note. 

Routier,  on  blood  in  purpura,  202. 

Rush,  Dr.,  his  case  of  suspended  cerebral 
activity,  637. 
56 


S. 

Sadler,  Mr.,  on  proportion  of  sexes,  809. 

Sanders,  Dr.,  on  structure  of  spleen,  159, 161. 

Sanderson,  Prof.,  case  of,  657. 

Saunders,  Mr.  E.,  on  dentition,  857,  858. 

Savart,  M.,  on  production  of  musical  tones, 
704. 

Scharling,  Prof.,  on  excretion  of  carbonic 
acid  from  lungs,  306 ;  from  skin,  308 ;  on 
amount  of  carbon  excreted,  307. 

Scherer,  Prof.,  on  absorbent  power  of  hee- 
matin,  177 ;  on  hue  of  red  corpuscles, 
195  ;  on  excretion  of  urea,  391. 

Schiff,  on  lesion  of  thalami  optici,  498 :  on 
corpora  striata,  499  ;  on  crura  cerebri, 
499  ;  on  Cerebellum,  515. 

Schleisner,  Dr.,  on  sanitary  condition  of 
Iceland,  69  note,  325  note. 

Schlossberger  and  Kemp,  on  proportion  of 
nitrogen  in  alimentary  substances,  65 
note. 

Schlossberger,  Prof.  Julius,  on  sausage  poi- 
soning, 74,  75  note;  on  absorption,  144 
note. 

Schmidt,  on  diameter  of  dried  blood-corpus- 
cles, 175;  on  method  of  analysing  blood, 
186  note;  on  sugar  in  blood,  191.  See 
Bidder  and  Schmidt. 

Schmidt,  Prof.,  on  acid  of  the  stomach,  109 
note;  on  pancreatic  fluid,  121. 

Schneider,  Dr.,  his  case  of  electric  disturb- 
ance, 429. 

Schonlein,  Prof.,  on  ammoniaco-magnesian 
phosphates  in  faeces,  130  note. 

Schottin,  Dr.,  on  uraemia,  389  note  ;  on  solid 
matters  of  perspiration,  403. 

Schreger,  on  absorption  by  cutaneous  lym- 
phatics, 149. 

Schrceder,  Van  der  Kolk,  Prof.,  on  coagula- 
tion of  blood,  211,  212. 

Schroeder,  on  action  of  saliyain  the  stomach, 
103. 

Schwann,  Prof.,  on  tonicity  of  small  arteries, 
261 ;  on  division  of  bile-duct,  126. 

Schwann  on  action  of  bile  in  digestion,  126. 

Seebeok  and  Wartmann,  on  Daltonism,  687 
note. 

Seguin,  on  cutaneous  transpiration,  403. 

Serre,  Dr.,  on  structure  of  retina,  674  note; 
on  centre  of  visual  direction,  677  note;  on 
phosphenes,  688,  689. 

Serres,  M.,  on  effects  of  effusion  in  cms 
cerebelli,  501 ;  on  comparative  anatomy 
of  Cerebellum,  513  note;  on  its  pathology, 
513,520. 

Sharpey,  Prof.,  on  formation  of  decidua, 
765,  766. 

Shearman,  Dr.,  his  case  of  uraemia,  389. 

Sibson,  Dr.,  on  mechanism  of  respiration, 
298  note. 

Sieveking,  Dr.,  on  albuminous  crystallisa- 
tion, 188. 

Simon,  Dr.,  on  action  of  bile,  &c.,  on  blooi- 
corpuscles,  177  ;  on  composition  of  blood, 
189;  on  blood  in  typhus,  201;  on  varia- 
tions in  urine,  391 ;  on  variations  in 


882 


INDEX    OF    AUTHORS. 


milk,  820 ;  on  milk  of  different  animals, 
822. 

Simon,  Dr.  Franz,  on  effects  of  starvation  on 
fibrin,  218  note;  his  analysis  of  blood  of 
renal  vein,  219  note. 

Simon,  Mr.,  his  analysis  of  renal  blood,  199 ; 
on  composition  of  blood  in  disease,  199; 
on  effect  of  improvement  of  breed  on  quan- 
tity of  fibrin,  218  note;  on  nature  of 
fibrin,  217  note;  on  coagulation  of  blood 
in  the  vessels,  212;  on  thymus  gland, 
168,  164;  on  elimination  of  zymotic  poi- 
sons, 239  note;  on  cancerous  eachexia, 
328  note,  357  note. 

Simpson,  Dr.,  on  pathology  of  Cerebellum, 
520  note. 

Simpson,  Prof.,  on  analogy  between  puer- 
peral and  surgical  fever,  234 ;  on  regene- 
ration of  limbs,  344 ;  on  parturition,  775 
note;  on  hermaphrodism,  803  note. 

Sion,  Dr.,  his  case  of  fat  in  the  blood,  204. 

Sloan,  Dr.,  his  case  of  abstinence,  86. 

Smith,  Dr.  Andrew  on  Bushmen,  845. 

Smith,  Dr.  Southwood,  on  cutaneous  absorp- 
tion, 147  ;  on  cutaneous  transpiration,  404. 

Smith,  Dr.  Tyler,  on  cause  of  parturition, 
775  note. 

Smith,  Mr.  R.  A.,  on  pulmonary  exhalation, 
311. 

Smith,  Mr.  Richard,  his  case  of  blunted  sen- 
sibility, 549  note;  on  metallic  tractors, 
746  note. 

Snow,  Dr.,  his  experiments  on  respiration, 
302. 

Solly,  Mr.  S.,  on  Medulla  Oblongata,  457; 
on  optic  chiasma,  493  note. 

Southey,  Robt,  his  volitional  control  over 
his  mental  powers,  587. 

Bpallanzani,  on  respiration  in  hydrogen, 
309  ;  on  fertilizing  power  of  spermatozoa, 
751  note. 

Spencer,  Earl,  his  cases  of  protracted  gesta- 
tion, 778. 

Sladeler,  on  carbonaceous  acids  of  urinary 
extractive,  317  note,  395. 

Stanley,  Mr.,  his  case  of  softening  of  Spinal 
Cord,  474  note. 

Stewart,  Prof.  Dugald,  on  relation  of  mind 
and  matter,  538  note. 

Stevens,  Dr.,  on  gases  of  blood,  193. 

Streckner,  his  analysis  of  bile,  377. 

Stilling,  on  structure  of  Spinal  Cord,  452 ; 
on  columns  of  Spinal  Cord,  474;  on  vesi- 
cular nucleus  of  glosso-pharyngeal  nerve, 
489 ;  on  motor  roots  of  pneumogastric, 
466. 

Stokes,  Dr.,  on  evolution  of  light,  421. 

Symonds,  Dr.,  on  volitional  actions,  597 
note ;  on  death,  referred-to,  868  note. 


Tanquerel,  M.,  on  lead  poisoning,  230  note. 

Taylor,  Dr.  A.,  on  poisonous  change  in 
meat,  75  note;  on.  protracted  gestation, 
referred-to,  777 ;  on  middle  point  of  foe- 
tus, 851 


Tessier,  M.,  his  cases  of  protracted  gesta- 
tion, 778. 

Thackrah,  Mr.,  on  coagulation  of  blood  in 
the  vessels,  211  ;  on  proportions  of  clot 
and  serum,  213. 

Thiele,  Prof.,  on  hypospadias,  802  note. 

Thompson,  Dr.  R.  D.,  on  milky  serum, 
190;  on  gastric  juice,  108,  109. 

Thompson,  Prof.  A.,  on  Peyerian  glands, 
153  note;  on  double  monstrosity,  340 
note. 

Tiedemann  and  Gmelin,  MM.,  on  action  of 
bile  in  digestion,  125:  their  experiments 
on  absorption,  143. 

Tiedemann,  Prof.,  on  heart's  action  in  vacuo, 
242  note. 

Tilanus,  on  saliva,  104  note. 

Tod,  Mr.,  on  duration  of  irritability  of  heart, 
241. 

Todd,  Dr..  on  artificial  epilepsy,  502;  on 
commissures  of  Cerebrum,  527 :  on  deli- 
rium, 627  ;  on  chorea,  636 ;  on  epilepsy, 
643  ;  on  general  Physiology  of  Nervous 
system,  referred-to,  649  note;  (see  Todd 
and  Bowman). 

Todd  and  Bowman,  on  structure  of  mucous 
membrane  of  stomach,  107:  on  red  cor- 
puscles of  ox,  173;  their  sketch  of  red 
corpuscles  of  pigeon,  174;  on  structure 
of  Spinal  Cord,  452 ;  on  nerves  of  taste, 
465  note;  on  peculiar  excitability  of  frog, 
478  note;  on  muscular  tension  487;  on 
corpora  striata  and  thalami  optici,  490  ; 
on  papillae  of  tongue,  660—663 ;  on  olfac- 
tory nerve,  665,  666 ;  on  adaptation  of 
eye  to  distances,  669  note;  on  cochlear 
nerve,  693  note. 

Tomes,  Mr.,  on  removal  of  bone  by  absorp- 
tion, 335. 

Townsend,  Col.,  case  of,  868. 

Toynbee,  Mr.,  on  structure  of  kidney,  re- 
ferred-to, 382  note;  on  membrana  tym- 
pani  and  its  muscles,  695,  696. 

Traill,  Dr.,  on  fat  in  the  blood,  204. 

Treviranus,  Prof.,  on  complemental  nutri- 
tion, 227. 

Trousseau,  M.,  on  suspended  lactation,  817 
note. 

Turck,  Dr.,  on  pathological  changes  in  Spi- 
nal Cord,  454. 

Turley,  Mr.,  his  case  of  excessive  sexual 
desire,  520  note. 


TJ. 

Unzer,  Prof.,  on  reflex  action,  479;  his 
general  Physiology  of  the  Nervous  Sys- 
tem, referred-to,  648  note. 


V. 

Valentin,  Prof.,  on  sense  of  hunger,  81  note 
on  movements  of  stomach,  95  :  on  move 
ments  of  intestinal  canal,  98 ;  on  bile  in 
faeces,  131 ;  his  estimate  of  amount  of 
blood,  171  note;  on  excitement  of  heart's 
action  by  irritation  of  the  pneumogastric, 


INDEX    OF    AUTHORS. 


883 


243  ;  on  sounds  of  heart,  252  ;  on  amount 
of  blood  discharged  from  heart,  253  n(.t-,  • 
on  influence  of  sympathetic  on  aorta,  2<// ; 
on  rate  of  blood's  movement  in  cap^ila- 
ries,  269  ;  on  excitability  of  mucous  sur- 
face of  trachea  and  bronchi,  295 ;  on 
quantity  of  air  respired,  299,  300 ;  on  in- 
terchange of  gases  in  respiration,  302  ; 
on  excretions  of  herbivora,  361 ;  on  facial 
nerve,  465 ;  on  glosso-pharyngeal,  465 ; 
on  roots  of  pneumogastric,  466  ;  on  spinal 
accessory,  469  ;  on  hypoglossal,  470  ;  on 
cephalic  nerves  generally,  472 ;  on  co- 
lumns of  Spinal  Cord,  477  note  ;  on  olfac- 
tory nerves,  491 ;  on  optic  nerve,  491 ; 
on  sense  of  touch,  655  ;  on  motor  actions 
of  sympathetic  nerves,  737 ;  on  evolution 
of  ovum,  754 ;  on  discharge  of  ovum 
from  ovisac,  759. 

Van  Deen,  on  columns  of  Spinal  Cord,  473. 

Vanner,  his  estimation  of  the  quantity  of 
blood,  170. 

Verdeil,  on  composition  of  ashes  of  blood, 
188. 

Vierordt,  on  number  of  blood-corpuscles, 
175;  on  quantity  of  air  respired,  299, 
302 :  on  per-centage  of  carbonic  acid  in 
expired  air,  302  :  on  circumstances  affect- 
ing this,  304,  307. 

Villerme",  M.,  on  infantile  mortality,  420. 

Virchow,  on  fatty  degeneration  of  uterus 
after  parturition,  335. 

Vogel,  on  excretion  of  urea,  392. 

Vogt,  his  case  of  paralysis  of  fifth  pair, 
466 ;  on  changes  in  germinal  vesicle, 
764. 

Volkmann,  Prof.,  on  sounds  of  heart,  252; 
on  amount  of  blood  discharged  from 
heart,  253  note ;  on  force  of  heart's  con- 
traction, 255;  on  rate  of  pulse  in  the 
aged,  256  note ;  on  the  influence  of  stature 
on  the  pulse,  257  note;  on  pressure  of 
liquids  within  rigid  tubes,  262 ;  on  dila- 
tation of  arteries  of  pulse- wave,  263 ;  on 
rate  of  movement  of  blood  in  arteries,  264 ; 
lateral  pressure  of  blood  within  arteries, 
265,  266  ;  on  rate  of  blood's  movement  in 
capillaries,  269;  on  contractility  of  bron- 
chial tubes,  286 :  on  discrimination  of 
sensory  impressions,  444 ;  on  structure 
of  Spinal  Cord,  450  note,  453  ;  on  motor 
roots  of  pneumogastric,  466 ;  on  inter- 
mixture of  sympathetic  fibres  with  pueu- 
mogastric,  739  note. 

Von  Ammon,  Dr.,  on  influence  of  passion 
on  mammary  secretion,  742  note. 

Vrolik,  Prof.,  on  double  monstrosity,  340, 
note;  on  comparative  enlargement  of  the 
face,  420  note;  on  varieties  in  form  of 
pelvis,  831. 

W. 

Wade,  Sir  C.,  his  case  of  Trance,  868  note. 

Wagner,  Prof.,  on  proportion  of  colourless 
corpuscles  to  red,  180;  on  motor  roots  of 
pneumogastric,  466;  on  tactile  papillae, 


653 :  on  spermatozoa,  750 ;    on   changes 
in  germinal  vesicle,  764. 

Walker,  Mr.  A.,  on  intermarriage,  779 
note. 

Wallace,  Dr.  Clay,  on  adaptation  of  eye  to 
distances,  669  note. 

Waller,  Dr.  Aug.,  on  reproduction  of  nervous 
substance,  487 ;  on  papillae  of  tongue, 
662  wte  ;  on  influence  of  sympathetic  on 
wr  •  of  arteries,  260,  on  heat,  417;  on 
r  ,  .1,  675. 

W,  .s,  Mr.,  his  case  of  deficient  encephalic 
f  jwer,  50  note. 

9»  alshe,  Dr.,  on  cancerous  cachexia,  857 
note. 

Wardrop,  Mr.,  on  influence  of  passion  on 
mummary  secretion,  742  note. 

Wartmann  and  Seebeck,  on  Daltonism,  687 
note. 

Wasmann,  on  pepsin,  109,  110. 

Watson,  Dr.,  on  absorption  of  vapour,  148. 

Weber,  Profrs.,  on  development  of  blood- 
corpuscles  in  liver,  161 ;  on  epithelium- 
cells  of  intestinal  villi,  136  note;  on 
amount  of  blood,  171 ;  on  arrestment  of 
heart's  action  by  electro-magnetic  cur- 
rent, 243 ;  on  effects  of  electro-magnetic 
current  on  small  arteries,  259 ;  on  dia- 
meter of  capillaries,  267  ;  on  acceleration 
of  blood  by  contraction  of  arteries,  265 ; 
on  rate  of  blood's  movement  in  capil- 
laries, 269 ;  on  effects  of  electricity  on 
capillary  circulation,  273;  on  size  of 
pulmonary  air-cells,  285 ;  on  tactile  sen- 
sibility, 654-656 ;  on  sensibility  of  tongue, 
659;  on  motion,  716  note;  on  sounds  of 
vibrating  reeds,  722 ;  on  formation  of 
decidua,  765-767  note ;  on  vesicula  pros- 
tatica,  800-802  note  ;  on  varieties  of  form 
of  pelvis,  831. 

Webster,  Dr.,  his  case  of  softening  of  Spinal 
Cord,  474  note. 

Wehsarg.  on  composition  of  faeces,  130. 

Welker,  on  number  of  red  corpuscles,  176. 

Wheatstone,  Prof.,  on  binocular  vision,  678- 
681 ;  on  estimation  of  size,  682-684  ;  on 
the  pseudoscope,  684 ;  on  falsetto  voice, 
725. 

White,  Mr.,  his  case  of  reproduction  of  su- 
pernumerary thumb,  344  note. 
\  Whitehead,  Mr.,  on  menstrual  fluid,  756. 
.  Willan,  Dr.,  his  case  of  abstinence,  86. 
i  Williams,  Dr.  C.  J.  B.  on  destruction  of 
blood-corpuscles,  203 ;  on  colourless  cor- 
puscles, 222 ;  on  elimination  of  morbid 
poisons,  239  note;  on  force  required  to 
propel  the  blood,  240  note ;  on  sounds  of 
heart,  251 ;  his  experiments  on  the  to- 
nicity  of  blood-vessels,  261-263,  277; 
on  contractility  of  bronchial  tubes,  286, 
287 ;  on  maintenance  of  animal  heat  by 
artificial  respiration,  415  ;  on  death  from 
necraemia,  867  note  ;  on  proximate  causes 
of  death,  868  note. 

Williams,  Dr.  R.,  on  morbid  poisons,  239. 

Williams,  Dr.  T.,  on  disintegration  of  hepatio 
cells,  376 


884 


INDEX    OF    AUTHORS. 


Willis,  Dr ,  on  functions  of  cranial  nerves, 
445  ;  on  hypoglossal  nerve,  470. 

Willis,  Mr.,  on  the  voice,  727  note;  his 
artificial  glottis,  728;  on  vowel  sounds, 
729. 

Wilson,  Mr.  E.,  on  mucous  membrane  of 
alimentary  canal,  107, 108  ;  on  muciparous 
glands  of  small  intestine,  129;  on  con- 
gestion of  liver,  373  note;  on  sudori- 
parous glandulse,  402. 

Woodall,  his  remedy  for  syncope,  247  note. 

Wohler,  on  action  of  soluble  salts  on  kid- 
neys, 399. 

Wollaston,  Dr.,  on  optic  chiasma,  493  note. 

\Vrisberg,  on  loss  of  blood,  171 ;  on  vica- 
rious secretion  of  urine,  365. 


Wynne,  Dr.,  his  Report  on  Cholera  in  the 
United  States,  320. 

Y. 

Yarrell,  Mr.,  on  assumption  of  male  plumage 
by  female,  228. 

Z. 

Zanarelli,  on  fat  in  the  blood,  204. 

Zander,  on  succus  entericus,  127. 

Zimmerman,  Dr.,  on  nature  of  fibrin,  217 
note;  on  relative  quantity  of  fibrin  in 
remote  veins,  219  note;  on  effects  of  loss 
of  blood,  192;  on  uraemia,  389  note. 

Zwicky   on  organization  of  blood-clot  209. 


INDEX   OF   SUBJECTS. 


Aberration,  chromatic  and  spherical,  668. 

Abortion,  776. 

Abscesses,  formation  of,  354. 

Absence  of  Mind,  601. 

Absorbent  Cells,  135,  136. 

Glandulge,  152-155. 

Vessels,   133,  147;    see    Lacteals 

and  Lymphatics. 

ABSORPTION,  general  nature  of  the  func- 
tion, 52,  133. 

From  Alimentary  Canal,  by  Blood-ves- 
sels, 133,  140-146;  circumstances 
affecting  rate  of,  140-143  ;  by  Lacteals, 
135,  136. 

From  Body  in  general,  by  Lymphatics, 
146-149,'  150;  by  Sanguiferous  system, 
146-149. 

Of  Vapours,  148;  by  lungs,  312,  313. 
Of  effete  Tissues,  332-337. 

Abstinence  from  Food,  duration  of  life 
under,  85,  86. 

Abstraction,  intellectual  process  of,  584. 

mental,  601 ;  involuntary,  601- 

603 ;  voluntary,  599,  600. 

Acardiac  Foetus,  movement  of  blood  in,  271. 

Acidity  of  Urine,  causes  of,  396,  397. 

Acquired  Perceptions,  554-556. 

Adhesion,  reparation  of  wounds  by,  343, 
345;  secondary,  348. 

Adolescence,  characteristics  of,  859,  860. 

^Esthetic  sense,  557. 

Afferent  nerve-fibres,  429,  442-446. 

African  races,  842,  843,  844. 

Age,  influence  of,  on  demand  for  food,  51, 
855;  on  composition  of  blood,  189;  on 
rate  of  pulse,  256 ;  on  excretion  of  car- 
bonic acid,  305;  on  nutritive  activity, 
337,  338 ;  on  excretion  of  urea,  391 ;  on 
power  of  calorification,  407,  418-421,  864 
note;  on  rate  of  growth,  813  ;  on  rate  of 
mortality,  811,  864  note. 

Ages,  different,  characteristics  of,  848-850; 
foetal  life,  851,  852 ;  infancy,  852,  853 ; 
childhood,  853-858 ;  youth,  859 ;  adoles- 
cence, 859-861 ;  maturity,  861,  862 ; 
decline,  862,  863 ;  old  age,  863,  864. 

Air,  alterations  in,  by  Respiration,  see 
RESPIRATION. 

Air-cells  of  Lungs,  284-286. 

Albinoisui,  825. 

Albumen,  assimilation  of,  151  ;  normal  pro- 


portion of,  in  Blood,  186;  variations  o£ 
in  disease,  204,  205 ;  uses  of,  223,  224 ; 
transudation  of,  352,  353. 

Albuminose,  118,  196. 

Albuminous  constituents  of  food,  63,  64; 
68-70;  digestion  of,  117,  118,  127. 

Albuminuria,  386,  387 ;  blood  in,  204,  205. 

Alcohol,  rapid  absorption  of,  142 ;  injurious 
results  of  habitual  use  of,  78;  its  ten- 
dency to  produce  fatty  degeneration,  336 ; 
its  influence  on  liver,  375 ;  on  kidney, 
400 ;  use  of,  in  fever,  414. 

Alfourou  Race,  847. 

Aliment,  sources  of  demand  for,  50,  51 ; 
see  Food. 

Alimentary  canal,  development  of,  788, 
795. 

Alkalies,  effect  of,  on  urine,  400,  401. 

Alkaline  Phosphates  in  blood,  225 ;  in 
urine,  394,  395. 

Sulphates,  in  urine,  394. 

Alkalinity  of  Blood,  importance  of,  225 ; 
of  Urine,  causes  of,  396,  397. 

Allantois,  development  and  uses  of,  790, 
791. 

American  Race,  845. 

Amnion,  development  of,  788,  789 ;  liquor 
of,  791. 

Amphioxus,  nervous  system  of,  438. 

Anaemia,  state  of  blood  in,  202. 

Ancon  breed  of  sheep,  832  note. 

Animal  Functions,  48,  49,  50-58;  their 
relations  to  the  Organic,  49,  50. 

Heat,  see  Heat,  Animal. 

Magnetism,  see  Mesmerism. 

Anthropomorphism,  544.  545. 

Aorta,  development  of,  790-793;  contrac- 
tion of,  by  irritation  of  Sympathetic,  260. 

Aplastic  Exudations,  354,  355. 

Apoplexy,  predisposition  to,  202. 

Apparent  Death,  868,  869. 

Arab  Race,  839. 

Arciform  fibres  of  Medulla  Oblongata,  456. 

Area  Germinativa,  787. 

Pellucida,  787. 

Vasculosa,  788,  789. 

Arian  Race,  837,  838. 

Arrest  of  Development,  329 ;  of  circulating 
apparatus,  793:  of  sexual  organs,  801, 
802 ;  of  visceral  arches  of  face,  806. 

Arsenic,  elimination  of,  from  body,  230. 

Arterial  Blood,  differential  characters  of, 
193-196. 

(885) 


886 


INDEX    OF    SUBJECTS. 


System,   first  development  of,  789, 

790 ;  subsequent  changes  in,  792. 

Arteries,  movement  of  Blood  in,  258,  266 ; 
diameter  of,  258 ;  properties  of  coats  of, 
259 ;  irritability  of,  259,  260 ;  influence  of 
electrical  and  other  stimuli  upon,  259, 
260;  influence  of  nerves  upon,  260;  to- 
nicity  of,  260,  261 ;  regulation  of  dia- 
meter of,  261,  262;  elasticity  of,  262; 
pulsation  of,  261-263 ;  rate  of  movement 
of  blood  in,  263  ;  lateral  pressure  of  blood 
in,  265,  266. 

Arthritic  diathesis,  70. 

Articulate  Sounds,  production  of,  727-732 : 
vowels,  728,  729 ;  consonants,  729,  730. 

Arytenoid  CariUages,  718;  movements  of, 
718,  719. 

Asphyxia,  pathology  of,  314-316;  in  rela- 
tion to  capillary  circulation,  272,  273 ; 
death  by,  314-316,  867;  imperfect 
closure  of  tricuspid  valve  in,  251 ;  in- 
creased pressure  within  systemic  arteries 
in,  273. 

Cutaneous,  404,  414. 

Assimilation,  general  nature  of  the  func- 
tion, 52,  53;  performed  by  Liver,  150, 
151,  376;  by  Absorbent  system,  152, 
158;  by  Vascular  glands,  165-167. 

Association  of  Ideas,  laws  of,  575,  580. 

Asthenia,  death  by,  867. 

Asthma,  spasmodic,  647;  contraction  of 
bronchial  tubes  in,  286,  287. 

Atavism,  780. 

Atlantidaj,  839. 

Atrophy,  328,  341;  conditions  of,  341- 
343. 

Attention,  influence  of,  on  Sensations  gene- 
rally,  547-549 ;  on  Perceptions,  555-557  ; 
on  Ideas,  580,  581 ;  Voluntary  fixation 
of,  599,  600;  effect  of,  on  acuteness  of 
Touch,  657,  658;  on  Taste,  664;  on 
Smell,  667  ;  on  Vision,  690  ;  on  Hearing, 
704,  705. 

—  Expectant,  production  of  Move- 
ments by,  591-596,  738 :  influence  of,  on 
Organic  functions,  745-746. 

Auditory  Ganglia,  458,  488. 

Nerves,  494 ;  ultimate  distribu- 
tion of,  691,  692,  693 ;  effects  of  section 
of,  497,  498. 

Automatic  activity  of  Spinal  Cord,  477, 
478,  485-487 ;  of  Sensory  Ganglia,  502- 
505;  of  Cerebrum,  542,  543,  573,  584- 
587. 

Axile  bodies,  of  tactile  papillae,  652-655. 

Axioms,  fundamental  of  Human  Thought, 
562. 

Azygos  Veins,  793-795. 


B. 


Baltimore,  Cholera  at,  321-323. 
Barrackpore,  mortality  of  troops  at,  324. 
Basque  Race,  838. 

Beauty,  sense  of,  557 ;  notion  of,  563. 
Bellar'y,  Cholera  at,  319. 


Berber  Race,  839. 

Bile,  secretion  of,  by  hepatic  cells,  377 ; 
from  venous  blood,  378 ;  excrementitious 
character  of,  361,  377,  380 ;  partly  formed 
from  products  of  disintegration,  378,  380 ; 
partly  from  newly-absorbed  materials, 
380,  381  :  effects  of  suspension  of,  376- 
379 ;  re-absorption  of,  from  gall-bladder, 
365,  380;  vicarious  secretion  of,  365; 
composition  of,  376,  377;  quantity  of, 
126;  its  uses  in  digestion,  124-127;  its 
re-absorption  from  intestine,.  131, 361, 381 ; 
its  presence  in  faeces,  131,  361. 

Bile-pigment,  378 ;  its  passage  into  urine, 
394. 

Biliary  cells,  372 ;  degeneration  of,  375, 
376. 

Biological  state,  598,  602,  603. 

Blastodermic  membrane,  784,  786,  787. 
-  Vesicle,  787,  788. 


Blind  persons,  acuteness  of  touch  in,  657, 
658 ;    improvement   of  hearing   in,   704, 
705. 
BLOOD,  general  character  and  purposes  of, 

169,  170  ;  quantity  of,  170,  171. 
Composition  of,  in  Health,  185-188:  modi- 
fication of,  by  age,  189  ;  by  sex,  189  ; 
by  food  and  drink,  190-192;  by  loss 
of  blood,  192 ;  differences  of  Arterial 
and  Venous,  193-196;  peculiarities  of 
portal  blood,  196 ;  of  mesenteric  blood, 

196,  197 ;  of  splenic  blood,  167,  168, 

197,  198 ;    of  hepatic  vein,  198,  199  ; 
of  renal  vein,  ]  99. 

Composition  of,  in  Disease,  199  ;  increase 
of  fibrin,  199-201 ;  diminution  of  fibrin, 

201,  202 :  increase   of  red  corpuscles, 
202 ;    diminution    of    red    corpuscles, 

202,  203;   increase   of  colourless  cor- 
puscles, 203  ;  diminution  of    albumen, 

204,  205 ;    increase  of    fatty   matter, 
204 ;  altered  proportion  of  salts,  205 ; 
of  water,  205 ;  presence  of  poisons  in, 

205.  206,  230-239. 

Corpuscles  of,  Red;  form,  size,  and  aspect 
of,  173-176;  composition  of,  176,  177; 
influence  of  reagents  on,  177 ;  ten- 
dency to  aggregation  of,  178;  produc- 
tion and  disintegration  of,  181 ;  em- 
bryonic development  of  181,  182;  sub- 
sequent development  of,  from  lymph- 
corpuscles,  182-185;  change  of  colour 
in,  by  respiration,  195,  196;  their 
uses,  220,  221 ;  variations  in  amount 
of,  in  disease,  202,  203  ;  destruction  of, 
202,  203 ;  mutual  attraction  of,  in 
coagulation,  178,  214;  adhesion  of,  to 
walls  of  vessels,  273 

Corpuscles  of,  Colourless;  form,  size,  and 
aspect  of,  178,  179;  peculiar  move- 
ment of,  in  capillaries,  179,  180;  change 
of  form  of,  179,  180;  numerical  pro- 
portion of,  to  red,  180;  development 
of,  into  red,  182-185;  their  uses, 

221,  222;  their  variations  in  number, 

222,  223 ;  multiplication  of,  in  disease, 
203. 


INDEX    OF    SUBJECTS. 


887 


Pressure  of,  against  walls  of  heart,  255 ; 

against  arteries,  263-266. 
Properties  of,  Physical,  171-173. 
Properties  of,    Vital,  206;  coagulation  of 
(see   Coagulation),    207-215;    uses   of 
fibrin  of,  215-220;  uses  of  corpuscles 
of.    220-223;    uses    of    albumen    of, 
223,  224 ;  uses  of  fatty  matter  of,  224, 
225 ;  uses  of  inorganic  components  of, 
225;  purification  of,  by  excretory  pro- 
cesses,  226,   227 ;   composition  of,  de- 
termines modes  of  nutrition,  227-229 ; 
327,  328;  life  of,  229,  238;  self-main- 
taining power  of,   229,   230;    elimina- 
tion of  poisons  from,  230,  231 ;  contami- 
nation of,  by  morbid  poisons,  225,  239. 
Rate  of  Propulsion  of,  by  heart,  253-255 ; 
rate  of  movement  of,  through  arteries, 
202-265;  through  capillaries,  266-269; 
through  veins,  275-278. 
Blood-vessels,  Absorption  by,  from  alimen- 
tary canal,  143-146;  from  body  in  gene- 
ral, 146-149 ;    influence  of  state    of,  on 
coagulation  of  contained  blood,  209-211  ; 
see  Arteries,  Capillaries,  Veins, 
Bone,    degeneration    and    regeneration   of, 

334,  335. 

Brain,  see  Cerebrum,  Cerebellum,  and  Sen- 
sory Ganglia. 

Branchial  Arches,  789-791. 
Breeds  of  Animals,  origination  of  new,  832. 
Bright's  disease  of  Kidney,  386,  387 ;  state 

of  blood  in,  203,  204. 
Bronchial  tubes,  contractility  of,  286,  287. 
Brunner's  Glands,  127. 
Buffy  Coat  of  blood,  213-215. 
Bulbus  arteriosus,  784. 
Bushmen,  of  Southern  Africa,  831,  845. 

C. 

Calcutta,  black  hole  of,  316. 

Calorific  Value  of  different  articles  of  food, 
66,  67. 

Calorifying  Power,  sources  of,  411-415; 
see  Heat. 

Cancerous  growths,  327  note,  357. 

Capillaries,  structure  of,  266,  267;  dia- 
meter of,  267 ;  arrangement  of,  268,  269 ; 
rate  of  movement  of  blood  through,  269 ; 
its  variations,  270 ;  its  independence  of 
heart's  action,  270,  271 ;  its  regulation 
by  conditions  operating  in  capillaries 
themselves,  272-274;  influence  of  ner- 
vous system  on,  275 ;  influence  of  shock 
on,  275. 

Carbonic  Acid,  in  Blood,  193;  sources  of 
production  of,  in  system,  280-282;  its 
exchange  for  oxygen  in  respiration,  302- 
304;  circumstances  affecting  quantity 
generated,  304-309 ;  extrication  of,  from 
skin,  308 ;  elimination  of,  by  atmosphere 
of  nitrogen  or  hydrogen,  309. 

Cardiac  plexus  of  Sympathetic,  774,  775. 

Carnivorous  animals,  respiration  of,  303, 
304 :  excretions  of,  360-362. 

Casein  of  Milk,  819. 


Castration,  influence  of,  on  growth  of  hair 

and  horns,  228. 

Catalepsy,  cases  of,  869 ;  Mesmeric,  622. 
Caucasian  Race,  837  ;  variety  of  colour  in, 

826. 

Celtic  Race,  838. 

Cephalic  Ganglia  of  Invertebrata,  433. 
Nerves,  general  character  and  re- 
lations of,  471,  472. 

Cerebellum,    peculiar    to   Vertebrata,    439, 
511;    structure   and   relations    of,    511- 
614 ;  relative  development  of,  in  diiferent 
animals,  514 ;  results  of  experiments  on, 
514,    515;    pathological   phenomena    of, 
516;  functions  of,  517-522. 
Cerebration,  unconscious,  587—589. 
Cerebro-spinal  fluid,  530. 
Cerebro- Spinal   System,    see   NERVOUS    SYS- 
TEM, Cerebellum,  Cerebrum,  Medulla  Oblon- 
gata,  Sensory  Ganglia,  Spinal  Cord. 
Cerebrum,  peculiar  to  Vertebrata,  61,  438; 
its    inferiority    in    lower    Vertebrata, 
438;  its  relative  size  in  diiferent  ani- 
mals, 532,  533 ;  its  vast  predominance 
in  Man,  522 ;  variations  of  size  in  him, 
533 ;  its   structure,  523-528 ;    cortical 
substance,   523 ;   medullary  substance, 
524,    525;    its  radiating   fibres,    525; 
its  commissures,  525-528 ;  its  weight, 
629;   its   supply  of  blood,  629,  530; 
development  of,  806-808. 
Functions    of,    530-637,    624,    625;    its 
relation  to  Intelligence  as   contrasted 
with  Instinct,  530-534,  536,  537;  effects 
of  its  removal,  496,  497,  634;  of  sus- 
pension of  its  activity,  637,  640;    in- 
formation  deducible    from   its   patho- 
logy,  535 ;    its    functional    connection 
with  Sensory  Ganglia,  536,  537 ;  its  au- 
tomatic activity,  542,  543;   (See  Mind.) 
Abnormal    activity    of,   625,  636;    Deli- 
rium,   626,    627;    Mania,    627,    628; 
Insanity,  628-633  (see  Insanity) ;  Hys- 
teria, 633,  634;    Hallucinations,   634; 
Chorea,  635. 

Chjetodon  rostratus,  instinct  of,  555. 
Change    of    matter    required    in    Organic 

functions,  362,  363. 

Childhood,  characteristics  of,  854,  855 ;  dis- 
eases of,  860,  861. 
Chimpanzee,  comparison  of,  with  Man,  34, 

43. 
Chloride    of   Sodium,   in    blood,   225;    in 

urine,  395. 
Chlorosis,  state  of  blood  in,  202,  203;  treat 

incut  of,  215  note. 
Chorda  dorsalis,  787,  788. 
Cholera,    state   of  blood  in,  202-205;   in 
fluence  of  putrescent  food  in  developing, 
78  note;   influence  of  imperfect  respira- 
tion in  developing,  317,  328;   thirst  of, 
relieved  by  saline  injections,  82. 
Cholesterin  in   Bile,  377;   in   Blood,  187; 

increase  of,  in  old  age,  229. 
Chordce   Vocales,    717-719;    regulation    of 
their  tension,  719,  720;  nature  of  their 
action,  721-726. 


888 


INDEX    OF    SUBJECTS. 


Chorea,  pathology  of,  635,  636. 

Chorion,  formation  of,  765  ;  tufts  of,  767- 
769. 

Chromatic  Aberration,  668. 

Chyle,  composition  of,  155,  156 ;  micro- 
scopic characters  of,  156,  157;  assimila- 
tion of,  158,  159. 

Chyme,  formation  of,  by  digestive  process, 
115-120. 

Cicatrization,  process  of,  346-348. 

Ciliary  ganglion,  462,  735,  736. 

Ciliary  muscle,  function  of,  668,  669. 

CIRCULATION,  53 ;  general  plan  of,  239- 
241 ;  action  of  Heart  in,  241-257  (see 
Heart]  ;  action  of  Arteries  in,  258- 
266  (see  Arteries) ;  action  of  Capil- 
laries in,  266-275  (see  Capillaries) ;  ac- 
tion of  Veins  in,  275-278  (see  Veins'). 
Peculiarity  of,  in  Cranium,  278,  279, 
529,  530 ;  in  Erectile  tissues,  279,  280. 
In  Foetus,  early  type  of,  789,  791 ; 
changes  in  plan  of,  790 ;  plan  of,  in 
mature  foetus,  795-797. 

Cirrhosis,  of  liver,  374,  375. 

Civilization,  influence  of,  on  form  of  skull, 
829,  830  ;  on  body  in  general,  831-833. 

Clairvoyance,  623. 

Claremont,  lead-poisoning  at,  76. 

Classification,  mental  process  of,  577,  578. 

Cloaca,  799. 

Coagulable  Lymph,  effused  for  reparation, 
345 ;  in  inflammation,  353-355. 

Coagulation  of  Blood,  172,  207 ;  essen- 
tially due  to  solidification  of  fibrin,  207, 
208 ;  an*  act  of  vitality,  208,  209 ;  occa- 
sional deficiency  of,  209-215;  retarda- 
tion of,  209-211;  effect  of  external  in- 
fluences on,  210-213 ;  influence  of  rest, 
210  ;  influence  of  warmth,  210;  effect  of 
neutral  salts,  210,  211  :  non-effect  of  sur- 
rounding atmosphere,  21 1 ;  influence  of 
depressed  vitality  or  death  of  vessels, 
211,  212;  influence  of  admixture  of  dead 
matter,  212,  213;  varying  proportions 
of  serum  and  clot,  213 ;  formation  of 
buffy  coat  in,  213-215. 

Cochlea,  functions  of,  698,  699. 

Cochlear  nerve,  distribution  of,  691,  692. 

Coenaesthesis,  553,  554. 

Coffee,  effect  of,  on  urine,  399,  400. 

Coition,  share  of  Male  in,  752,  753;  of 
Female,  758. 

Cold,  influence  of,  on  tonicity  of  arteries, 
259-261 ;  power  of  resisting,  variation 
of,  with  age,  418-421,  864  note;  power 
of  generating,  420 ;  death  by,  412-414, 
867. 

Colostrum,  818-820. 

Colour  of  Blood,  changes  of,  195,  196. 

of  Skin,  variation  of,  in  Man,  825, 

826. 

Colours,  want  of  power  to  discriminate, 
687,  688,  705;  production  of  comple- 
mentary, 686,  687 ;  modification  of,  by 
juxtaposition,  687. 

Colourless  corpuscles,  see  Blood. 

Coma,  640;  Mesmeric,  620-624. 


Comparison,  intellectual  process  of,  584. 

Commissures  of  Cerebrum,  525-528. 

Complemental  Nutrition,  doctrine  of,  227, 
228. 

Complementary  Colours,  686,  687. 

Conception,  act  of,  772,  773. 

Conduct,  determination  of,  by  the  Will, 
604,  605 ;  influence  of  Motives  on,  606- 
609. 

Conduction  of  sonorous  vibrations,  893. 

Congestion,  predisposition  to,  201 ;  of  liver, 
various  forms  of,  373,  374 ;  venous, 
causes  of,  277,  278. 

Conscience,  nature  of,  563-565, 

Consciousness,  the  foundation  of  all  Mental 
activity,  545,  546 ;  seat  of,  in  Sensory 
Ganglia,  502,  503,  536,  537. 

Conversions  of  Relief,  683-685. 

Convulsive  Diseases,  644-648, 

Co-ordination  of  Movements,  the  probable 
function  of  the  Cerebellum,  514,  525; 
influence  of  habit  on,  708. 

Corpora  Malpighiana,  of  Kidney,  384,  385 ; 
their  uses,  386 ;  morbid  changes  in,  386 ; 
of  Spleen,  160;  uses  of,  167. 

Olivaria,  456. 

: —  Pyramidalia,  456-458. 

Quadrigemina,  488 ;  their  functions, 

497. 

Restiformia,  457. 

• Striata,    489,    490 ;     functions    of, 

498,  499  ;  connection  of,  with  Cerebrum, 
525,  526. 

Wolffiana,  799. 

Corpus  Callosum,  525,  526;  cases  of  de- 
ficiency of,  528  note. 

Dentatum,  457. 

Luteum,  formation  of,  758-762. 

Corpuscles  of  Blood,  see  Blood. 

of  Chyle,  156,  157;  their  trans- 
formation into  blood-corpuscles,  182-184. 

Correlation  between  Mind  and  Force,  541- 
545. 

Coughing,  act  of,  296. 

Cranial  vertebrae,  804-806. 

Cranio-Spinal  Axis,  the  fundamental  por- 
tion of  the  Cerebro-Spinal  System,  437  ; 
see  Medulla  Oblongata  and  Spinal 
Cord. 

Cranium  of  Man,  compared  with  that  of 
Apes,  34-37,  40-42 ;  different  forms  of, 
827-830;  peculiarity  of  circulation  in, 
278,  279,  529,  530. 

Crassamentum,  172,  173,  207;  proportion 
of,  to  serum,  273. 

Creatine  and  Creatinine,  components  of 
blood,  187,  225 ;  of  urine,  393. 

Critical  Evacuations,  401. 

Crura  Cerebri,  motor  and  sensory  tracts  of, 
458-460 ;  effects  of  section  of,  499. 

Crying,  act  of,  295. 

Crystals  of  Blood,  187,  188. 

Cutaneous  Asphyxia,  404,  405,  414,  415. 

—  Respiration,  307,  308,  414,  415. 

Transpiration,  401-405 ;  see  Su- 
doriparous Excretion. 

Cysts,  pilifr  rous  and  dentigerous,  341. 


INDEX    OF    SUBJECTS. 


889 


D. 


Daltonism,  687. 

Deaf  and  Dumb,  506,  726. 

Death,  the  necessary  consummation  of  Life, 
849,  863,  864;  somatic,  864-867;  mole- 
cular, 864-868;  apparent  and  real,  868, 
869 ;  signs  of,  869. 

Decidua,  formation  of,  765,  766,  767  ;  its 
share  in  formation  of  placenta,  769,  770, 
771. 

Decline,  period  of,  862,  863. 

Defecation,  act  of,  99,  483. 

Degeneration,  continual,  of  living  tissues, 
329-331,  333-337 ;  of  muscle,  333,  342 ; 
of  bone,  333-335;  of  teeth,  337;  in- 
creased tendency  to,  in  inflammation,  349- 
351 ;  of  lymph  and  its  products,  353- 
355. 

Calcareous,  862,  863. 

Fatty,   335,   336 ;    favoured  by 

habitual  use  of  alcoholic  liquors,  78,  336 ; 
tendency  to,  during  period  of  decline, 
862 ;  of  Uterus,  333,  774 ;  of  Hepatic 
cells,  375,  376 ;  of  Renal  cells,  387. 

Deglutition,  act  of,  90,  91 ;  nerves  of,  91, 
92. 

Deity,  Anthropomorphic  and  Pantheistic 
views  of,  544,  545 ;  notions  of,  563,  564. 

Delirium,  626,  627,  628. 

Delusions,  632,  633,  634 ;  Epidemic,  590. 

Dentition,  first,  853;  second,  856- 
858. 

Determinations  of  Blood,  local,  causes  of, 
271,  272. 

Deutencephalon,  development  of,  807. 

Development,  a  source  of  demand  for  nutri- 
tion, 328,  329  ;  its  difference  from  growth, 
329;  arrest  of.  316,  792,  795,  802,  803, 
806;  period  of,  850,  861. 

Development  of  Embryo,  general  plan  of, 
783,  784;  earliest  stages  of,  784-786; 
segmentation  of  yolk,  785-788 ;  forma- 
tion of  blastodermic  vesicle,  787;  foun- 
dation of  Vertebral  column  and  Nervous 
centres,  787,  788;  development  of 
Amnion,  788,  792;  vascular  area,  788; 
Vitelline  vessels,  789;  Heart  and  Arte- 
rial system,  789,  793;  Allantois,  790, 
791 ;  Umbilical  vessels  and  placental 
villi,  790;  Venous  system,  793,  795; 
Alimentary  canal,  787,  795 ;  Liver,  796, 
797 ;  Spleen  and  other  vascular  glands, 
161-165 :  Lungs,  798  ;  Urinary  organs, 
798;  Generative  apparatus,  800-803; 
Mammary  gland,  815 ;  Skeleton,  802-806  ; 
Nervous  Centres,  787,  806,  807 ;  cephalic 
nerves,  471 ;  Eye  and  Ear,  808. 

Diet,  Animal,  67;  Vegetable,  67;  mixed, 
68 ;  of  trainers,  73,  74 ;  different  scales 
of.  71-73  ;  influence  of,  on  composition 
of  Blood,  192;  on  Respiration,  303-306; 
on  Excretion  generally,  360-363 ;  on  com- 
position of  Urine,  397,  398. 

Diffusion  of  gases,  law  of,  302. 

DIGESTION,  general  nature  of,  52. 
Buccal,  102,  103. 


Gastric,  a  process  of  chemical  solution, 
115;  time  required  for,  116  ;  limited  to 
azotized  substances,  117 ;  influence  of 
various  conditions  on,  120. 

Intestinal,    influence   of   pancreatic   fluid 
in,  120-124;    of  bile  in,  124-127;  of 
succus  entericus,  127,  128 ;  its  univer- 
sal efficacy,  127,  128. 
Dingo,  Australian,  breeding  of,  832  note. 
Direction  of  sounds,  judgment  of,  698,  704. 

,  visual  sense  of,  676,  690. 

,  Centre  of,  690. 

Discus  proligerus,  759. 

Disintegration  of  Tissues,  see  Degeneration. 

Distance,   adaptation   of  eye  to,  668-670; 

visual   appreciation   of,  681,  682 ;    audi- 
tory appreciation  of,  704,  705. 
Diuretics,  effect  of,  on  urine,  400,  401. 
Diurnal  variation  of  pulse,   258,   259;   of 

respiration,   307;    of   temperature,  407, 

408. 

Divining  Rod,  rationale  of,  593,  594. 
Dominant  Ideas,  influence  of,  in  producing 

movement,  590,  591 ;  in  directing  current 

of  thought,  605;    on   action   of  mind  in 

Insanity,  632-634. 
Double  Monsters,  339,  340,  850. 
Dreaming,  616-618. 
Dublin    Lying-in    Hospital,    mortality    in, 

324-326. 
Drink,  water  the  natural,  76;  influence  of, 

on  composition  of  blood,  190-192 ;  effects 

of  Alcoholic,  77-79,  335. 
Ductless  Glands,  structure  of,  158, 159,  165  • 

functions  of,  165-168. 
Ductus  Arteriosus,  792-795. 

Cuvieri,  793-795. 

Venosus,  793-795. 

Duration,  relative,  of  different  parts  of  the 

Organism,  329-331. 
Duty,  idea  of,  606-609. 
Duverney's  Glands,  758  note. 

E. 

Ear,  external,  700-702  ;  internal,  695,  705 ; 
see  Hearing,  Organ  of. 

Earthy  Phosphates,  in  urine,  394-396. 

Ectopia  Cordis,  case  of,  248,  252. 

Education,  objects  of,  540,  541. 

Efferent  nerve-fibres,  430,  442-446. 

Ejaculatio  Seminis,  752 ;  its  independence 
of  sensation,  482-485. 

Elasticity  of  Arteries,  262 ;  of  Veins,  275 ; 
of  Lungs,  287,  288;  of  walls  of  Chest, 
289. 

Election,  seats  of,  226. 

Electricity,  Evolution  of,  in  living  body,  422. 
423 ;  connection  of,  with  nutritive  and 
secretory  operations,  422,  423  ;  Muscular 
current  of,  423-425;  disturbance  of,  in 
muscular  contraction,  426 ;  Nervous  cur- 
rent of,  427,  428 ;  disturbance  of,  in  ner- 
vous action,  428,  429 ;  peculiar  cases  of, 
429,  430. 

Influence    of,    on   coagulation    of 


blood,  209 ;  on  action  of  heart,  243 ;  on 


890 


INDEX    OF    SUBJECTS. 


arteries,  260  ;  on  mesocephale,  500,  502  ; 
on  nerves  of  special  sense,  652. 

Electro-Biological  state,  597,  602,  603. 

Embryo,  development  of,  see  Development. 

Embryonic  life,  peculiarities  of,  849,  850. 

Emotional  Actions,  567,  568 ;  their  source 
in  the  Cerebrum,  535,  536 ;  their  distinct- 
ness from  volitional  actions,  568,  569 ; 
their  effect  in  relieving  emotional  excite- 
ment, 570,  571. 

Insanity,  630,  631. 

Sensibility,  553,    554,    558,  559: 

its  association  with  Ideas,  constituting 
Emotions,  566,  567. 

Emotions,  nature  of,  566,  567 ;  excitation 
of  by  muscular  suggestion,  620-623 ; 
their  direct  action  in  producing  move- 
ment, 567,  568 ;  their  channel  of  opera- 
tion, 568,  569;  their  action  on  organic 
functions,  738-745 ;  their  influence  on 
intellectual  processes,  570;  their  expen- 
diture in  bodily  change,  570,  571 ;  their 
influence  on  volitional  movements,  571, 
572  ;  their  agency  as  motives,  606,  607 ; 
their  unconscious  action,  588,  589 ;  their 
perverted  action  in  Insanity,  627,  628, 
632,  633;  in  Hysteria,  633,  634;  in- 
fluence  of,  on  stammering,  731,  732. 

Epencephalic  Vertebra,  805. 

Epencephalon,  development  of,  787,  788, 
806. 

Epidemic  Delusions,  590. 

Diseases,     predisposition    to,    in 

state  of  Blood,  233,  234 :  from  putrescent 
food,  74,  76 ;  from  putrescent  water,  76 ; 
from  alcoholic  liquors,  78-80 ;  from  star- 
vation, 83,  84 ;  from  insufficient  respira- 
tion, 316-327. 

Epilepsy,  pathology  of,  642,  643. 

Epithelial  tissues,  exuviation  and  replace- 
ment of,  332,  333,  343,  344. 

Erectile  tissues,  circulation  in,  279. 

Erect  Vision,  cause  of,  676,  677. 

Esquimaux  Race,  845 ;  pyramidal  skull  of, 
828. 

Ethiopian  Race,  842-844. 

European  Nations,  837-840. 

Euskarian  Language,  839. 

Eustachian  Tube,  functions  of,  696,  697. 

Valve,  uses  of,  795. 

Excito- Motor  Actions  of  Spinal  Axis,  477- 
482 ;  their  independence  of  sensation, 
478-481 ;  their  adaptative  character,  481  ; 
their  relation  to  the  Organic  functions, 

482,  483 ;    their    protective    character, 

483,  484 ;  their  subservience  to  locomo- 
tion,   485,    486;    their   establishment  by 
habit,  486,  487. 

EXCRETION,  general  nature  of,  54-56 ; 
sources  of  demand  for,  54,  359;  statics 
of,  360-363 ;  complementary  relation  of 
different  modes  of,  363,  364;  vicarious 
forms  of,  363,  365,  366. 

Exercise,  influence  of,  on  excretion  of  car- 
bonic acid,  306,  307 ;  on  composition  of 
urine,  389-391  ;  on  temperature  of -body, 
408. 


Exhalation  of  aqueous  vapour,  from  Lungs 
310,  311;  from  Skin,  402-404;  frigori 
fying  effect  of,  410-412,  420,  421. 

Exhaustion,  Death  by,  causes  of,  414,  866. 

Expectant  Attention,  see  Attention,  Ex- 
pectant. 

Expiration,  movements  of,  288,  289 ;  force 
required  for,  289,  290. 

Extractive,  of  Blood,  187,  188;  of  Urine, 
393,  394. 

Externality,  elementary  notion  of,  554,  555. 

Extra-uterine  foetation,  762,  763,  774,  775. 

Exudations,  reparative,  344-346 ;  inflam- 
matory, 352,  353. 

Exuviation  of  effete  Tissues,  332,  335,  337. 

Eye.  optical  structure  of,  668-671 ;  adapta- 
tion of  to  distances,  670,  671 ;  nervous 
organization  of,  see  Retina;  use  of  in 
Vision,  see  Vision;  development  of,  808. 

Eyes,  convergence  of  axes  of,  in  object, 
670,  677,  678,  712,  713 :  movements  of, 
directed  by  visual  sense,  505,  506 ;  rela- 
tion of  Will  to,  508,  509 ;  harmony  and 
symmetry  of,  708-713. 

F. 

Facial  Angle  of  Man  and  Apes,  42. 

Nerve,  464,  465. 

Faeces,  composition  of,  130,  131 ;  source  of 
their  peculiar  constituents,  131,  132; 
expulsion  of,  99,  482,  483 ;  fatty  matter 
in,  224. 

Fakeers,  Indian,  apparent  death  of,  868. 

Fallopian  Tubes,  development  of,  799 ; 
passage  of  spermatozoa  through,  758; 
passage  of  ova  through,  763,  764 ;  for- 
mation of  chorion  in,  764,  765. 

False  Perceptions,  634,  635,  641,  642. 

Falsetto  Voice,  nature  of,  725,  726. 

Farinaceous  constituents  of  food,  see  Starch. 

Faroese  islanders,  diet  of,  74,  75. 

Fat,  in  Blood,  186,  187;  uses  of,  224,  225; 
increase  of,  in  disease,  204;  in  old  age, 
229;  in  Chyme,  emulsification  of,  121- 
124 ;  in  Fasces,  224,  225 ;  production  of, 
in  Liver,  150,  198,  372,  380. 

Fecundation,  act  of,  764 ;  seat  of,  762. 

Feelings,  simple,  associated  with  Sensations, 
553 ;  with  Ideas,  566,  567. 

Female,  physiological  peculiarities  of,  see 
Sex;  mental  constitution  of,  813;  Length 
and  weight  of,  at  birth,  809,-810; 
subsequent  increase  of,  812 ;  viability 
of,  811;  puberty  of,  756;  influence  of, 
on  progeny,  779-782  ;  on  sex,  808 ;  share 
of,  in  Generation,  see  GENERATION. 

Fenestra  ovalis  and  rotunda,  694-696. 

Fever,  alterations  of  blood  in,  201,  202; 
sources  of  predisposition  to,  233,  234; 
mortality  from,  323. 

Fibrin  of  Blood,  its  non-identity  with 
muscle-fibrin,  216,  217 ;  normal  propor- 
tion of,  186,  199;  increased  proportion 
of,  in  arterial  blood,  193,  194;  in  splenio 
vein,  197;  augmentation  of,  in  inflam- 
mation, 188,  189;  diminution  of,  in 


INDEX  OF  SUBJECTS. 


891 


adynamic  diseases,  201,  202;  its  coagu- 
lation, 207,  208  (see  Coagulation);  its 
uses,  216-220. 

Fibrin  of  Chyle,  155-157. 

of  Lymph,  155,  157,  158. 

Fibrinous  effusions  of  Inflammation,  352, 
353  ;  conservative  nature  of,  354. 

Fifth  Pair  of  Nerves,  distribution  and 
functions  of,  461,  462;  its  action  in 
mastication,  87,  90 ;  in  deglutition,  91 ; 
in  respiration,  291 ;  its  agency  in  taste, 
461,  464,  466;  in  smell,  491,  665;  its  in- 
fluence on  salivary  secretion,  739,  740. 

Filiform  papillae  of  tongue,  660-663. 

Finnish  Race,  840. 

Fish,  brain  of,  compared  with  Man's,  438. 

Flute-pipes,  laws  of,  772. 

Foetus,  circulation  in,  795 ;  mode  of  deter- 
mining age  of,  851,  852 :  nature  of  life 
of,  849,  850 ;  size  and  weight  of,  at  birth, 
810 ;  development  of  organs  in,  see 
Development. 

Food,  sources  of  demand  for,  50-52 ; 
general  purposes  and  applications  of,  52- 
54 ;  classification  of  components  of,  63 ; 
saccharine  and  oleaginous  constituents  of, 
63,  64,  68,  69 ;  albuminous  constituents 
of,  63,  64,  68;  gelatinous  constituents 
of,  64,  65;  proportions  of  carbon  and 
nitrogen  in  different  articles  of,  65 ;  calo- 
rific and  histogenetic  value  of,  65,  66; 
most  economical  combinations  of,  66,  67  ; 
relative  value  of  animal  and  vegetable, 
67-70;  quantity  of,  needed  by  Man, 
71-73 ;  importance  of  purity  of,  74-76  ; 
consequences  of  deficiency  of,  82—86 ; 
prehension  and  ingestion  of,  86,  87  ;  re- 
lative digestibility  of  different  kinds  of, 
116,  117  ;  influence  of  nature  of,  on  com- 
position of  blood,  190-192;  on  respira- 
tion, 303,  304 ,  on  excretion,  360-362. 

Force,  its  relation  to  Mind,  541-545. 

Form,  mode  of  acquiring  knowledge  of,  by 
Touch,  655 ;  by  Vision,  676-679. 

Formative  Power,  of  individual  parts,  327- 
331 ;  excess  of,  in  hypertrophy,  338-340 ; 
deficiency  of,  in  atrophy,  341,  342;  mani- 
festation of,  in  reparative  process,  343- 
348  ;  deficiency  of,  in  inflammation,  349- 
351  •  its  greater  energy  in  earlier  than 
in  later  periods  of  life,  337,  338,  343, 
850. 

Fornix,  525-528. 

Fourth  Pair  of  Nerves,  463,  464. 

Free- Will,  543 ;  belief  in  our  own,  562. 

Frigorification,  influence  of  cutaneous  ex- 
halation in,  411,  412,  420. 

Functions,  Vital,  46;  Organic,  47,  48; 
Animal,  48,  49;  their  mutual  relations, 
43,  50 ;  see  ABSOKPTION,  ASSIMILATION. 
CIRCULATION,  &c. 

Fungiform  papillae  of  Tongue,  694,  695. 


G. 

Ganglia,  structure   of,  430-432;  see  NER- 
VOUS SYSTEM. 


Ganglia  of    Sympathetic   system,  see  Sym- 
pathetic. 

Gaols,   Indian,   high  rate   of  mortality  in, 
324;    English,  Cholera  in,  317-320;    at 
Nisrnes,  mortality  in,  84. 
Gases,  absorption  of,  302  ;  diffusion  of,  304. 

of  Blood,  193,  194. 

Gastric  follicles,  structure  of,  104,  108. 
Gastric  Juice,  composition  of,  108-110;  con- 
ditions of  its  secretion,  110-113;   quan- 
tity of  secreted  daily,  111;  influence  of 
nervous   system   on,  113-115 ;    740  note, 
740,  741;  solvent  power  of,  115-120. 
Gasserian  ganglion,  461,  462  ;  its  influence 

on  nutrition,  744. 
Gelatin,  uses  of,  as  food,  64,  65. 
GENERATION,  general  nature  of,  57 ;  provi- 
sions for  its  performance,  746,  747. 
Action  of  Male  in,  748-758 ;  structure 
of  testes,  748,  749 ;  characters  of  semi- 
nal fluid,  749,  750;  nature  and  evolu- 
tion of  Spermatozoa,  750,  751 ;  essen- 
tial importance  of  Spermatozoa  in 
fecundation,  751,  752,  764;  puberty, 
epoch  of,  751,  752;  sexual  desire,  521, 
522,  752;  coition,  752. 
Action  of  Female  in,  753,  789 ;  structure 
of  Ovum,  753,  754 ;  evolution  of  ovum, 
754,  755 ;  period  of  puberty,  755,  756 ; 
menstrual  discharge,  756-758 ;  coinci- 
dent ovulation,  757,  758;  duration  of 
procreating  period,  758 ;  her  function 
in  coition,  758 ;  maturation  of  ova, 
758-760;  corpus  luteum,  758-761; 
fecundation  of  ovum,  762-764 ;  con^ 
sequent  changes,  764 ;  formation  of 
chorion,  765 ;  formation  of  decidua, 
765-767  ;  of  villi  of  chorion,  767-769  ; 
of  foetal  tufts,  769 :  of  Placenta,  769, 
770 ;  changes  in  Uterus  during  ges- 
tation, 772 ;  quickening,  772 ;  partu- 
rition, act  of,  773,  774;  period  of, 
774,  777,  778:  superfoetation,  778,  779; 
see  Lactation,  Mammary  Gland,  Milk. 
Influence  of  Parents  on  progeny,  779, 
780 ;  effects  of  near  relationship  of, 
780,  781 ;  influence  of  Male  on  subse- 
quent offspring,  781,  782;  effects  of 
state  of  parents  at  time  of  conception, 
781 ;  subsequent  influence  of  Mother, 
745,  746,  782,  783 ;  influence  of  Ages 
of  parents  on  Sex  of  progeny,  808. 
Embryonic  Development,  see  Development 

of  Embryo. 
Generation,  Organs  of,  their  development, 

800-803. 

Germinal  Capacity,  variation  of,  at  different 
ages,  849,  850. 

Membrane,  786,  787. 

Spot,  753,  754. 

Vesicle,  754,  755 ;  its  disappear- 
ance after  fecundation,  763,  764. 
Gestation,  ordinary  term  of,  774,  775 ;  ab- 
breviated,   776,    777 ;    protracted,    777, 
778. 

Glands,  Assimilating,  of  Absorbent  System, 
152-155;  their  functions,  157,  158;    of 


892 


INDEX    OF    SUBJECTS. 


Sangtiiferous  system,  158-165 ;  their  func- 
tions, 165-168  ;  double  character  of  Liver, 
375-377. 

Secreting,  essential  nature  of,  357, 

358. 

Glosso-Pharyngeal  Nerve,  distribution  and 
functions  of,  464-466 ;  its  instrumen- 
tality in  deglutition,  91,  92 ;  in  sense  of 
taste,  464-466. 

Glottis,  regulation  of,  715-721;  artificial, 
723,  724. 

Gorilla,  comparison  of,  with  Man,  33,  84. 

Graafian  vesicle,  753 ;  formation  of  ovum 
within,  754;  escape  of  ovum  from,  758, 
759;  subsequent  changes  in,  759-761. 

Granulation  of  wounds,  847,  348. 

Growth,  period  of,  850-861. 

a  source  of  demand  for  nutrition, 

328;  excess  and  deficiency  of,  328;  its 
difference  from  development,  329;  for- 
mative activity  during  period  of,  850- 
861. 

Guiding  Sensations,  essential  to  voluntary 
movements,  505-507 ;  their  influence  in 
ideo-motor  actions,  591,  592  ;  see  Muscu- 
lar Sense. 

Gustatory  Ganglia,  488,  489. 

Nerves,  465,  466,  494. 


H. 

Habit,  influence   of,  in  establishing  excito- 
motor  actions,  485,  486 :  on  sensori-motor 
actions,  504,  505 ;  on  intensity  of  sensa- 
tions,   548,    549 :    on  perceptions,    554- 
559 ;    on   succession    of  ideas,  574,  575 
603-607  ;  on  impressions  on  sleeping  per- 
sons,  613,  614;  on  amount  of  sleep  re- 
quired,   615.    616;    on    co-ordination   of 
muscular  movements,  707,  708. 
Hachish,  effects  of,  618,  626. 
Haemorrhage,  predisposition  to,  201,  202. 
Hair,  characters  of,  in  different  Races,  826 

827. 

Hallucinations  of  Insanity,  632-635. 
Hand  of  Man,  peculiar  attributes  of,  33, 34 
Harmony    of    Muscular    movements,    708- 

714. 
Healing  Processes,  different  forms  of,  344- 

348. 

Hearing,  physical  conditions  of,  690-695. 
Organ  of,  its  essential  structure,  691, 
692  ;  its  adaptation  to  laws  of  propaga- 
tion of  sounds,  693-695 ;  structure  and 
functions  of  tympanic  apparatus,  695- 
698 ;  of  labyrinth,  698,  699 ;  of  exter- 
nal ear  and  meatus,  700-703. 
Sense  of,  703-706 ;  discrimination  of  pitch 
of  tones,  700,  703-706;  estimate  of 
direction  of  sounds,  698,  704 ;  estimate 
of  distance,  704,  705 ;  influence  of  ha- 
bitual attention  on  acuteness  of,  704, 
705;  rapidity  of  perception  by,  com- 

Eared  with  vision,  705  ;  use  of,  in  regu- 
iting  voice,  506,  507,  705,  706. 
Hear^  irritability  of,  241 ;  rhythmical  move- 
ments of,  241-246  ;  their  source,  242-246  ; 


influence  of  nerves  upon,  242-245 ;  dis- 
turbance of,  by  attention  to  them,  738; 
succesive  actions  of,  247-250 ;  course  of 
blood  through,  249,  250;  difference  of 
two  sides  of,  250,  251;  sounds  of,  251- 
253 ;  rate  and  force  of  propulsion  of 
blood  by,  253-255 ;  number  of  pulsations 
of,  255-258;  first  development  of,  789, 
790  ;  subsequent  changes  in,  792-795. 

Heat,  influence  of,  on  Vital  Action,  405-407 , 
on  period  of  gestation,  774,  775 ;  en- 
durance of  extremes  of,  410-412 ;  its  pro- 
duction in  Human  body,  406;  sources  of 
variation  of,  407-409 :  alterations  of,  in 
disease,  409,  410;  liberation  of,  after 
death,  410;  sources  of,  411-413,  415; 
loss  of,  the  cause  of  death  by  starvation 
and  exhausting  diseases,  413-415;  partial 
dependence  of,  on  cutaneous  respiration, 
414,  415;  influence  of  nervous  system 
on,  415-418;  inferior  power  of  gene- 
rating, at  earliest  and  latest  periods  of 
life,  418-421,  864  note;  reduction  of,  by 
evaporation  from  external  surface,  420, 
421. 

Height,  at  different  ages,  812. 

Hepatic  Artery,  368-370. 

Cells,    372;    degeneration    of,   375, 

376. 

Duct,  370,  371. 

Parenchyma,  arrangement  of,  370- 

372 ;  nature  of,  376,  377. 

Vein,  368-370 ;  blood  of,  compared 

with  portal,  198,  199. 

Herbivorous  animals,  respiration  of,  396, 
397 ;  excretions  of,  360-363. 

Hereditary  transmission  of  psychical  cha- 
racter, 574,  575 ;  of  maladies,  780-782. 

Hermaphrodism,  802,  803. 

Heterologous  growths,  356,  357. 

Hiccup,  act  of,  295. 

Hindostan,  languages  and  people  of,  840,  84-1 

Hippuric  acid,  its  presence  in  the  Blood, 
187,  188,  225;  in  Urine,  392,  393. 

Histogenetic  value  of  different  articles  of 
food,  65,  66. 

Homicidal  Insanity,  630  note. 

Hottentot  Race,  844. 

Hybrid  Races,  question  of  fertility  of,  834. 

Hybrids,  influence  of  parents  on,  779,  780. 

Hunger,  indicates  necessity  for  aliment,  52, 
71 ;  immediate  source  of  sense  of,  80, 
81. 

Hydrogen,  elimination  of,  by  respiratory 
process,  310,  311;  by  other  excretions, 
360,  861  ;  respiration  in,  310-313. 

Hydrophobia,  pathology  of,  645. 

Hypertrophy,  328,  338 ;  conditions  of,  338, 
339 ;  shown  in  production  of  tumours, 
339,  340;  in  supernumerary  parts,  340, 
341. 

Hypnotism,  619,  620. 

Hypochondriasis,  operation  of,  746. 

Hypogastric  plexus  of  Sympathetic,  733- 
735. 

Hypospadias,  802,  803. 

Hypoglossal  Nerve,  469,  470 


INDEX    OF    SUBJECTS. 


893 


Hysteria,  emotional  perversion  in,  633,  634 ; 

convulsive  phenomena  of,  645,  646,  647 ; 

exalted   sensibility   in,  650;    remarkable 

case  of,  645,  646,  647  note. 
Hysterical  Ischuria,  364,  365. 

I. 

Icelanders,  freedom  of,  from  tuberculosis, 
69,  70 ;  liability  of,  to  zymotic  diseases, 
316,  317,  324-326. 

Ideas,  formation  of,  559,  560;  influence  of 
language  on,  560-562 ;  intellectual,  562- 
564 ;  their  succession,  determining  causes 
of,  572-575;  association  of,  575-580; 
exercise  of  intellectual  faculties  on,  580- 
587  (see  Intellectual  Faculties) ;  influence 
of  attention  in  intensifying,  580,  581 ; 
dominance  of,  see  Dominant  Ideas. 

Identification,  576,  577  ;  discoveries  of,  578. 

Ideo-Motor  Actions,  589-596;  to  be  con- 
sidered as  reflex  actions  of  Cerebrum, 
589 ;  the  expressions  of  dominant  ideas, 
590,  591  ;  prompted  by  expectant  atten- 
tion, 590-596. 

Idiocy,  predominance  of  instinct  in,  533, 
534 ;  remarkable  cases  of,  50  note,  570 
note,  609  note;  causes  of,  574,  575,  780, 
781. 

Illusions,  spectral,  641,  642. 

Imagination,  585,  586. 

Imitation,  tendency  to,  630  note. 

Impulsive  Insanity,  630,  631. 

Inanition,  see  Starvation. 

Incontinence  of  Urine,  647-648. 

Increase,  see  Growth. 

India,  population  and  languages  of,  840, 
841. 

Indo-European  race,  837-839. 

Induction,  process  of,  577-578. 

Infancy,  characteristics  of,  852-854. 

Infants,  temperature  of,  407 ;  inferior 
power  of  generating  heat  in,  419,  420; 
length  and  weight  of,  at  birth,  808-810. 

Inflammation,  increase  of  fibrin  of  blood 
in,  199-201 ;  a  perverted  form  of  nutri- 
tive process,  349 ;  its  relations  to  hyper- 
trophy and  atrophy,  349 ;  causes  of,  349- 
351  ;  phenomena  of,  351,  352 ;  state  of 
blood  in,  352  ;  characteristic  effusions  of, 
352-355;  unhealthy  forms  of,  353,  354; 
effects  of,  in  tubercular  subjects,  356. 

Inflammatory  effusions,  different  characters 
of,  222,  223,  352,  853. 

Inorganic  Constituents  of  Blood,  188;  their 
uses,  225 ;  of  Urine,  393-397. 

Insalivation,  100-104. 

Insanity,  its  nature  and  causes,  628,  629  ; 
disturbance  of  Intellectual  powers  in, 
629,  630 ;  Emotional  disturbance  in,  630, 
631 ;  Ideational  disorder  of,  624,  635. 

Insects,  automatic  actions  of,  433-435. 

Inspiration,  movements  of,  288,  289 ;  force 
required  for,  289,  290;  cause  of  first, 
291,  292. 

Instinct,  contrasted  with  Reason,  433-436. 

Intellectual  Faculties,  nature  of,  580,  581  ; 


Automatic  action  of,  572-575,  580,  586, 
587;  Volitional  direction  of,  543-545; 
580,  581,  584-586;  their  foundation  in 
Association,  575-580 ;  principal  kinds  of, 
581-586. 

Intelligence,  nature  of,  as  opposed  to  in- 
stinct, 435-437 ;  degree  of,  conformable 
to  size  and  development  of  Cerebrum, 
530-534. 

Intestinal  Canal,  movements  of,  97-99 ;  in- 
fluence of  Sympathetic  nerves  on,  98,  99; 
influence  of  mental  states  on,  738;  de- 
velopment of,  787,  788,  795,  796. 

Juice,  127,  128 ;  its  use  in  diges- 
tion, 127-129. 

Secretions,  influence  of  nervous 

system  on,  740,  741. 

Introspection,  581. 

Intuition,  its  relation  to  Perception,  554-556; 
its  manifestation  in  aesthetic  sense,  557 ; 
in  moral  sense,  557,  558 ;  in  emotional 
sense,  558,  559;  in  apprehension  of  truth, 
559,  560. 

Intuitive  perceptions,  554-556. 

Involuntary  Movements,  706-708 ;  influence 
of  Sympathetic  on,  736-739. 

Iris,  structure  of,  675 ;  movements  of,  see 
Pupil. 

Irradiation  of  impressions  on  retina,  687, 688. 

Irritability  of  Heart,  241,  242;  of  Arteries, 
259,  260. 

J. 

Jacob's  Membrane,  structure  of,  671-674. 

Jaundice,  ordinary,  from  re-absorption  of 
bile,  365,  366  ;  more  severe  form  of,  de- 
pendent on  non-elimination  of  bile,  379, 
380. 

Jewish  Females,  period  of  conception  in, 
763,  764  note. 

Nation,  839;  varied  complexion  of, 


826. 


K. 


Kaffre  Race,  843,  844. 

Kangaroo,  mammary  foetus  of,  87  note. 

Kidney,  structure  of,  381-386;  tubuli  urini- 
feri  of,  381-384;  circulation  in,  384,  385; 
Corpora  Malpighiana  of,  384-386;  secret- 
ing cells  of,  381-384;  development  of, 
798-800;  pathological  changes  in,  386, 
387;  elimination  of  water  by,  385,  386; 
of  soluble  matters  generally,  398,  399; 
secreting  action  of,  385,  386;  excretory 
function  of,  385-401 ;  (see  Urine). 

Kurrachee,  cholera  at,  318,  319. 


Labyrinth  of  Ear,  functions  of,  698,  699. 

Lachrymal  secretion,  influence  of  mental 
states  on,  740,  741. 

Lactation,  816,  817;  change  of  quality  of 
milk  in  course  of,  820,  821 ;  extraordinary 
prolongation  of,  820;  by  males,  817 


894 


INDEX    OF    SUBJECTS. 


Lacteuls,   origin  of,   in  villi,   133-135;    ab- 
sorption by,  140-143;  glandulae  of,  152- 
155  ;  contents  of,  see  Chyle. 
Laminae  dorsales,  787,  788. 
Landau,  effects  of  siege  of,  782,  783. 
Language,  the  expression  of  ideas,  558-562 ; 

loss  of  memory  of,  581,  582. 
Languages  of  different  races,  essential  con- 
formity in,  836 ;  American,  836,  837,  845; 
Bushman,  844;  Celtic,  839;   Euskarian, 
837-839 ;  Hindoo,  840,   841 ;    Hottentot, 
844,  845;  Indo-Germanic,  837-839;  Kaf- 
fre,  843,  844;    Malayo-Polynesian,  846, 
847;  Negro,  842,  843;  Negrito,  847,848; 
Sanskritic,  837-839  ;  Seriform,  440,  841 ; 
Syro- Arabian,  839 ;  Tamulian,  840,  841. 
Lanugo  of  foetus,  227. 
Lapps,  Race  of,  840. 
Laryngismus  stridulus,  647,  648. 
Larynx,  structure  of,   717,   719;  muscular 
actions  of,  719-721 ;   precise  adjustment 
of,  715,  716;  their  dependence  on  guiding 
sensations,  506,  507,  509,  510,  726,  727 ; 
nerves  of,  292,  293,  466-469 ;  spasmodic 
closure  of,  647,  648 ;  production  of  sounds 
by,  721-726;  theory  of  the  voice,  721- 
725  ;  falsetto  notes,  725,  726. 
Laughing,  act  of,  295. 

Lead,  poisoning  of  water  by,  76,  77  ;  cumu- 
lative action  of,  230,  231. 
Leaf,  fall  of,  47,  48,  331  note. 
Leucocythsemia,  202,  203. 
Life,  of  an  organism,  46 ;  of  the  Blood,  206, 

207,  215,  216,  229,  238. 
Light,  evolution  of,  from  living  body,  421, 

422. 

Lightning,  death  by,  effect  of  on  blood,  209. 
Limbs,  nature  and  development  of,  803,804; 
attempted  reproduction  of,  in  foetus,  343, 
344. 

Limits  of  Vision,  674,  675. 
Liquor  Amnii,  791. 

• Sanguinis,  172,  173  ;  composition  of, 

176,  177. 

Lithic  acid,  see  Uric  acid. 
Licer,  structure  of,  366-376 ;  general  plan 
of,  in  lower  animals,  366,  367 :  in  Man, 
367,  368,  376,  377;  arrangement  of 
blood-vessels  in,  368-370 ;  biliary  ducts 
in,  370,  371 ;  parenchyma  of,  370-372; 
component  cells  of,  372,  373  ;  develop- 
ment of,  796,  797  ;  pathological  changes 
In,  373-376;  double  function  of,  376, 
377. 

Assimilating  action  of,  150,  151,  198,  199, 
381 ;  production  of  fat  by,  150,  151, 
198,  199,  367,  381 ;  production  of  sugar 
by,  151,  198,  372,  381;  influence  of 
lesion  of  medulla  oblongata  on,  399  note; 
of  red  corpuscles  by,  151,  181, 182 ;  as- 
similation of  albumen  and  fibrin  by,  150, 
151,  188,  199;  subservience  of,  to  re- 
spiratory function,  380,  381. 
Excretory  action  of,  55,  56,  376,  377 ;  in 
foetus,  379,  380 :  formation  of  bile  by, 
377-381 ;  (see  Bile.) 
Lochia,  774. 


Locomotion,  movements  of,  485,  487,  504. 
505,  707,  708. 

Londonderry  steamer,  case  of,  316. 

Loss  of  Blood,  influence  of,  on  composition 
of  blood,  192,  193. 

Louisville,  Cholera  at,  320,  321. 

Luminosity,  of  living  body,  421,  422. 

Lungs,  structure  of,  282-286  ;  contractility 
of  bronchial  tubes  of,  286,  287 ;  elasticity 
of,  287  ;  force  required  for  their  disten- 
sion, 287  ;  mechanism  of  their  expansion, 
287,  289  ;  capacity  of,  298,  301 ;  changes 
in,  from  section  of  pneumogastrics,  296, 
297  ;  development  of  798. 

Lymph,  composition  of,  155 :  microscopic 
characters  of,  157;  sources  of,  149,  150; 
movement  of,  157,  158. 

Lymph,  Coagulable,  effusion  of,  in  inflam- 
mation, 353,  354 :  conservative  nature  of, 
354,  355  ;  fibrinous  and  corpuscular  forma 
of,  852,  353  ;  degenerations  of,  353,  355 ; 
formation  of  pus  from,  354,  355. 

Lymphatics,  distribution  of,  146 ;  glandulse 
of,  152-155;  absorption  by,  149,  150; 
contents  of,  see  Lymph. 


M. 


Magnetism,  Animal,  620-623. 

Magnetometer,  deception  of,  593  note. 

Magyar  Race,  840. 

Maintenance  of  organism,  332 :  during  pe- 
riod of  maturity,  850,  861,  862. 

Malayo-Polynesian  Race,  846,  847. 

Male,  rudimentary  uterus  in,  800;  rudi- 
mental  mammary  gland  in,  816 ;  lacta- 
tion by,  816,  817;  influence  of,  on  pro- 
geny, 779-782;  on  sex,  809;  size  and 
weight  of  at  birth,  808-810;  subsequent 
increase  of,  812;  viability  of,  811;  pu- 
berty of,  751,  752  ;  his  character  as  com- 
pared with  female,  813  ;  share  of  in  Gene- 
ration, see  GENERATION. 

Malignant  growths,  356,  357. 

Malpighian  Bodies  of  Kidney,  381-386 ;  of 
Spleen,  159,  161. 

Mammary  Gland,  structure  of,  813-816; 
functional  activity  of,  816,  817  ;  influence 
of  mental  states  upon,  741-745;  secretion 
of,  see  Milk. 

MAN,  Distinctive  Characters  of,  33 ;  hand 
of,  33,  34;  cranium  of,  34-37,  40-45; 
vertebral  column  of,  39 ;  lower  extremi- 
ties of,  39 ;  facial  angle  of,  42 ;  myology 
of,  42 ;  visceral  apparatus  of,  42 ;  brain 
of,  43  ;  subordination  of  senses  to  intelli- 
gence of,  43 ;  peculiar  adaptability  of,  43 ; 
slow  growth  of,  44 ;  mental  endowments 
of,  44 ;  articulate  speech  of  44,  45  ;  capa- 
city for  progress  of,  45. 

Epochs  of  Life  of,  848-850 ;  embryoni 

life,  850-852;  infancy,  852,  853;  child 
hood,  854-857  ;  youth,  859  ;  adolescence, 
859,  860;  maturity,  861;  decline,  862-864. 

Varieties   of,   836,  848;    see   Colour, 

Hair,    Languages,    Pelvis,    Races     Skull, 
and  Varieties. 


INDEX    OF    SUBJECTS. 


895 


Mania,  627,  628. 

Mara,  Mad.,  range  of  voice  of,  716  note. 

Mastication,   act  of,    87-90 ;    nerves  of,  87 

note. 

Materialist  hypothesis,  537-541. 
Maturity,  characteristics  of,  861,  862. 
Maucharnp  breed  of  Sheep,  832  note. 
Mecomum,  nature  of,  380,  381  note. 
Medulla   Oblongata,   structure  of,   454-461  ; 
motor  tract  of,   458,   461 ;  sensory  tract 
of,  458,  461 ;  special  endowments  of,  482 
(see  Spinal  Cord). 

Spinalis,  see  Spinal  Cord. 

Membrana  Granulosa,  753,  754. 

—  Tympani,  structure  and  uses  of, 
695,  696. 

Memory,  545,  546,  581,  582. 
Menstruation,  pe-riod  of,  755,  756 ;  nature 

of,  756,  757 ;  persistence  of,  758. 
Mesencephalic  Vertebra,  804,  806. 
Mesencephalon,   development  of,  788,  806, 

808. 

Mesenteric  Blood,  special  characters  of,  196. 
—  Glandule,  structure  of,  152-155. 
Mesmerism,  examination  of  reputed  pheno- 
mena of,  596,  620,  623. 
Mesocephale,  effects  of  section  of,  499  ;  ef- 
fects of  electric  current  on,  502. 
Metamorphosis  of  matter,  required  in  Or- 
ganic functions,  362,  364. 
Metastasis    of    Secretion,    363,    364,    365, 

366. 
Milbank  Prison,  scurvy  at,  84,  85  ;  cholera 

at,  317,  318. 

Milk,  secretory  apparatus  of,  813-816;  sup- 
ply of,  816,  817;  constituents  of,  817-820; 
variations  in  their  proportions,  817-821  ; 
influence  of  mental  states  on,  741,  745, 
746 ;  varieties  of,  in  different  animals, 
821,  822;  relation  of,  to  blood,  821,  822; 
re-absorption  of,  822  ;  vicarious  secretion 
of,  821,  823 ;  quantity  of,  secreted,  823, 
873  ;  passage  of  medicines,  &c.,  into,  873. 

,  Sugar  of,  819. 

MIND,  of  Man,  its  distinctive  characteristics, 
44,  45,  435-437;  Nature  of,  537-553; 
materialist  doctrine  of,  538,  539 ;  spi- 
ritualist doctrine  of,  538-540;  influence 
of  education  on,  540,  541 ;  its  relation 
to  Matter,  538,  539;  to  Force,  541,  542; 
correlation  of  its  action  with  actions  of 
Nervous  System,  541-554 ;  its  influence 
on  Organic  functions,  738-746 ;  succes- 
sion of  changes  in,  572,  574 ;  influence 
of  habit  on,  574 ;  hereditary  transmis- 
sion of  modes  of  action  of,  574,  575 ; 
variation  of,  at  different  periods  of  life, 
574,  576,  855,  856,  861-863. 
Automatic  activity  of,  542,  543,  573, 

584-687. 
Emotional  activity  of,  566-672,  738-744 

(see  Emotions}. 
Ideational     activity     of,    559-565     (see 

Ideas). 

Ideo dynamic  activity  of,  589-596,  738, 
745,  746  (see  Idea-Motor  actions,  and 
Expectant  Attention). 


Intellectual     activity    of,    575-586    (see 

Intellectual  Faculties). 
Intuitional     activity    of,    554-560     (see 

Intuition). 
Perceptional    activity    of,    554-557    (see 

Perceptions). 
Sensational     activity    of,    545-554    (see 

Sensations). 

Volitional  direction  of.  543-545,  572,  573 
574,  584-587,  599,  609  (see  Volition}. 

Model  Lodging-Houses,  sanitary  state  of, 
323,  324. 

Modelling  process,  345,  346  ;  means  of  pro- 
moting, 346,  347. 

Molecular  Death,  865-868. 

Mongolian  Race,  840,  841;  in  Europe,  837; 
in  India,  840,  841. 

Monomania,  630,  633,  634. 

Monstrosities,  by  excess,  338-340;  by  In- 
clusion, 340,  341;  by  arrest  of  develop- 
ment, 329,  792-795,  802,  804. 

Moral  Insanity,  630. 
Sense,  557,  558,  564,  565. 

Morbid  Poisons,  see  Povsons,  Morbid. 

Mortality,  preventive,  of  England,  826. 

relative,  at  different  periods   of 

the  year,  419,  420,  864  note;  at  different 
ages,  811,  812,  864  note. 

Mother,  influence  of  mental  states  of,  in 
foetus,  746,  782,  783  ;  on  mammary  secre- 
tion, 741-743. 

Motility  of  heart,  246. 

Motives,  influence  of,  605  ;  principal  orders 
of,  605-608. 

Motor  Nerves,  laws  of  transmission  through 
443,  444 ;  see  Efferent  Nerve-fibres. 

Tract    of   Medulla  Oblongata,   458- 

461. 

Movements,  Muscular,  voluntary  and  in- 
voluntary, 707 ;  grouping  of,  707,  708 ; 
symmetry  and  harmony  of,  708-714; 
energy  and  rapidity  of,  714—716;  precise 
adjustment  of,  716;  see  Muscular  Sense. 

Mucous  layer  of  Germinal  membrane,  786- 
788. 

Mule,  characters  of,  779,  780;  sterility  of, 
833,  834  note. 

Muscles,  limited  term  of  life  of,  329-331; 
degeneration  of,  333-335 ;  hypertrophy 
of,  338,  339 ;  atrophy  of,  342,  343 ;  elec- 
tric current  in,  422-424. 

Muscular  Apparatus  of  Organic  Life,  707, 
708;  of  Animal  Life,  707,  708;  volun- 
tary and  involuntary  actions  of,  707,  7  08 ; 
see  Movements, 

Muscular  Sense.  505 ;  its  participation  in 
voluntary  movements,  507  ;  its  exaltation 
in  Somnambulism,  619,  620. 

Suggestion,    its    influence  in   Som 

nambulism,  619,  620. 

Tension,   influence   of    Spinal  Cord 

on,  487,  488. 

Myopia,  670,  671. 

N. 

Navy,  diet- scale  of,  71-73. 
Necrsemia,  death  by,  206,  867. 


896 


INDEX    OF    SUBJECTS. 


Negrito  "Race,  847,  848. 
Negro,  change  of  colour  in,  825  note. 
Negro  Races,  colour  of,  825,  826;  hair  of, 
826,  827;   skull  of,  828,  829;    modifica- 
tion of  its  form  by  civilization,  830;  pelvis 
of,  831 ;  geographical  range  and  varieties 
of,  842,  843. 
Nerve-force,  laws  of  transmission   of,  442- 

444. 

Nerves,  electric  current  in,  427-429. 
NERVOUS  SYSTEM,  general  functions  of,  58, 
59 ;  influence  of,  on  Animal  Heat,  415, 
416;  general  arrangement  of,  430- 
433 ;  automatic  character  of,  in  Inver- 
tebrata,  433-436:  distinguished  in 
Vertebrata  by  Cerebrum,  and  minister- 
ing to  Intelligence,  435-437. 
Cerebro-  Spinal  system,  principal  divi- 
sions of,  61,  62,  436-442  ;  Cranio-Spinal 
Axis,  437  ;  Sensory  Ganglia,  437,  438 : 
Cerebral  Hemispheres,  438,  439 ;  Cere- 
bellum, 439;  general  course  of  action 
of,  438-440 ;  reflex  operations  of  sepa- 
rate parts,  439,  440 ;  subordination 
of  these  to  the  Will,  440;  relations 
of,  to  Sympathetic  system,  441,  442; 
influence  of,  on  Animal  Heat,  415-418; 
on  Organic  functions,  738-746  (See 
Cerebellum,  Cerebrum,  Medulla  Oblon- 
gata,  Sensory  Ganglia,  Spinal  Cord, 
Consciousness,  Emotions,  Excito-molor 
Actions,  Ideo-motor  Actions,  Intellectual 
Faculties,  Reflex  Actions,  Sensori-motor 
Actions,  Volitional  Actions'). 
Sympathetic  System,  general  structure 
of,  732-738;  Cerebro-Spinal  fibres  in, 
441,  442,  736;  their  instrumentality 
in  sensation  and  muscular  contraction, 
737,  738  ;  action  of,  on  intestinal  canal, 
97-99;  on  heart,  244;  on  blood-ves- 
sels, 260,  261;  on  uterus,  736,  773, 
774;  on  iris,  675;  Proper  fibres  of, 
733-735;  their  probable  functions, 
739;  influence  of,  on  Secretion,  739- 
741 ;  on  Nutrition,  743,  744 ;  on  Ani- 
mal Heat,  417,  418. 

Trunks,  endowments  of,  442-448;  affe- 
rent and  efferent,  442,  443 ;  use  of 
plexuses  of,  442,  443 ;  laws  of  trans- 
mission in,  443,  444;  modes  of  deter- 
mining their  functions,  444-448 ;  by 
peripheral  distribution,  444,  445 ;  by 
central  connections,  445,  446 :  by  ex- 
periment, 446,  447 ;  by  observation, 
447,  448. 

TIervous  Tissue,  limited  duration  of,  331 ; 
continual  reparation  of,  332,  333  ;  atrophy 
of,  342,  343. 

Nismes,  prison  of,  mortality  at,  84,  85. 
Nitric  Acid,  in  urine,  394-396. 
Nitrogen,  proportion  of,  in  different  articles 
of  food,  65,  66 ;    its  presence  in  blood, 
193;  exhalation  and  absorption  of,  310; 
excretion  of,  360-363. 
NUTRITION,  general  nature  of,  53,  54,  235, 
236 ;    dependent   on   pabulum   in   blood, 
227,  228,  327,  328 ;    complemental,  doc- 


trine of,  227-229  ;  sources  of  demand  for, 
in  increase,  328;  in  development,  328, 
329 ;  in  maintenance,  329-331 ;  con- 
ditions of  its  performance,  332;  inter- 
stitial and  superficial,  332-337;  varying 
activity  of,  337,  338  ;  at  different  periods 
of  life,  848-850;  abnormal  degrees  of, 
338-343;  peculiar  phases  of,  in  repara- 
tion of  injuries,  343-348;  abnormal 
forms  of,  349-357 ;  inflammation  and  its 
results,  349-355  ;  tuberculosis,  355,  356 ; 
malignant  growths,  356,  857 ;  influence 
of  Nervous  system  on,  54-58,  103,  104, 
742-745;  electric  disturbance  in,  422, 
423. 

0. 

Oblique  Muscles  of  Eye,  function,  709-711. 

Observation,  581  ;  active  in  infancy,  852. 

Oceanic  Eace,  846-848. 

Ocular  Spectra,  688,  689. 

Odoriferous  secretion  of  Skin,  influence  of 
nervous  system  on,  740,  741. 

Odorous  matter  in  Blood,  186,  187. 

Odours,  nature  of,  665. 

Odylic  Movements,  rationale  of,  593,  594. 

(Esophagus,  movements  of,  in  swallowing, 
91-93;  in  vomiting,  111,  112. 

Old  Age,  characteristics  of,  862,  863 ;  tem- 
perature in,  407-409 ;  diminished  power 
of  generating  heat  in,  419,  420,  864  note. 

Oleaginous  constituents  of  food,  63,  68,  69 ; 
digestion  of,  121-128. 

Olfactive  Ganglia,  488,  489. 

Nerves,  491,  492  ;  peculiar  charac- 
ter of,  665,  666 ;  distribution  of,  665,  666. 

Olivary  bodies,  456-458. 

Omphalo-mesenteric  vessels,  789,  790. 

Ophthalmic  branch  of  Fifth  Pair,  461 ,  462. 
Ganglion,  461,  462,  734-736. 


Optic  Ganglia,  488-491. 

Nerves,  peculiar  arrangement  of,  493, 

494;  endowments  of,  491,  494,  497;  dis- 
tribution of,  670,  671 ;  deficient  sensi 
bility  at  entrance  of,  673,  674,  688-689. 

Thalami,  489-491 ;  functions  of,  406- 

409. 

Orang  Outang,  comparison  of,  with  Man, 
33,  43. 

Organic  Functions,  46-48,  50-58;  their  re- 
lations to  the  Animal,  48-50. 

Oscillations  of  suspended  bodies,  591-595. 

Ossification,  completion  of,  a  mark  of  Ado- 
lescence, 859,  860. 

Oval  Skull,  828-830. 

Ovarium,  structure  of,  753,  754;  develop- 
ment of,  800,  801 ;  evolution  of  ovisacs 
within,  754,  755;  discharge  of  ova  from, 
758-763. 

Overcrowding,  a  predisposing  cause  of  zy- 
motic disease,  317-319,  324. 

Ovisac,  see  Graafian  Vesicle. 

Ovum,  structure  of,  753-755;  evolution 
of,  754,  755 ;  maturation  and  discharge 
of,  758-762;  fertilization  of,  763,  764; 
first  changes  in,  764,  765 ;  subsequent 
changes  in,  see  Development  of  Embryo. 


INDEX    OF    SUBJECTS. 


897 


Oxalic  Acid,  in  urine,  394-396. 

Oxygen,  sources  of  demand  for,  280-282 ; 
quantity  of,  required,  302  ;  exchange  of 
carbonic  acid  for,  301-304;  absorption 
of,  304:  excretion  of,  310,  311,  360-362; 
respiration,  313. 

P. 

Pain    and    Pleasure,    connection    of,   -with 

Sensations,  549 ;  with  Ideas,  566,  567. 
Pancreatic   Fluid,  composition  of,  120-124 ; 

uses  of,  in  digestion,  121-126 ;  amount  of 

secreted,  121-124. 
Pantheism,  544,  545. 
Papillae,  tactile,  652-654;  gustative,  660- 

663. 

Papuan  Race,  847. 
Par  Vagum,  see  Pneumogastric  Nerve. 
Paralysed  limbs,  temperature  of,  415,  416. 
Paralysis,  Encephalic,  642 ;  Spinal,  648. 
Paraplegia,  peculiar  cases  of,  479-481. 
Parents,  influence  of,  on  progeny,  see  GENE- 
RATION, Influence  of  Parents. 
Parotid  Gland,  100,  101 ;  secretion  of,  100- 

103. 
Parturition,  act  of,  773,  774 ;  regular  period 

and  causes  of,  774,  775;  premature,  776, 

777  ;  retarded,  777,  778. 
Passion,  influence  of,  on  secretion  of  Milk, 

741-743. 

Paupers,  dietary  of,  71-73. 
Pelagian-Negro  Race,  847. 
Pelvis,  form  of,  in  different  Races,  831. 
Pepsin,  108-110. 

Perception,  nature  of,  554;  influence  of  at- 
tention on,  556,  557 ;  influence  of  habit 

on,  556,  557. 
Perceptions,    intuitive   and   acquired,    554- 

556;  false,  634,  635,  641,  642. 
Periodical  phenomena,  406,  774. 
Peristaltic  movement  of  intestines,  97,  98 ; 

influence  of  mental  states  on,  738. 
Persistence  of  sensory  impressions,  gusta- 
tive, 664,  665;  olfactive,  667;  visual,  685, 

686 ;  auditory,  703,  704. 
Perspiration,  see  Sudoriparous  Excretion. 
Personal  Equation  of  Astronomical  observers, 

750. 
Peyerian  glandulse,  structure  and  relations 

of,  152,  155. 
Phosphates,   Alkaline,   in  blood,   225;    in 

urine,  394,  397. 

—  Earthy,  in  urine,  394,  396. 
Phosphenes,  investigation  of,  688,  689. 
Phosphorus,  elimination  of,  by  breath,  311, 

422 ;  by  urine,  394,  422. 
Phosphorescence  of  living  body,  421,  422. 
Phrenological  doctrine,  of  Cerebellum,  517, 

521 ;  of  Cerebrum,  534,  580. 
Pitch  of  Sounds,  appreciation  of,  699. 

of  Voice,  regulation  of,  719-724. 

Placenta,  formation  of  foetal  portion  of,  767, 

768 ;  of  maternal  portion,  769-771. 
Placental  murmur,  771. 
Pneumogastric  Nerve,    general   distribution 

and  endowments  of,  466-468 ;  its  instru- 

57 


mentality  in  deglutition,  91,  92  ;  in  hunger 
and  satiety,  80  note;  its  influence  on  se- 
cretion of  gastric  fluid,  113,  115,  739-741 , 
on  movements  of  stomach,  95 ;  on  move- 
ments of  heart,  243  ;  its  action  as  excitor 
of  respiration,  291  ;  its  influence  on  la- 
rynx, 293,  295,  466,  468. 

Pointer  and  Setter,  peculiar  breeding  of,  779. 

Poisons,  mode  of  action  of,  230,  231 ;  their 
passage  into  the  circulation,  253-255 ; 
elimination  of,  from  blood,  230-232,  238, 
239. 

Morbid,  their  substantive  existence, 

232,  233 ;  some  generated  within  the  sys- 
tem, 235,  236 ;  zymotic,  233  ;  predisposi- 
tion to  their  activity,  233,  234;  course 
of  action  of,  235,  236 ;  alteration  of  blood 
by,  237,  238;  recovery  of  blood  from, 
238,  239. 

Polynesian  Races,  846. 

Portal  Vein,  blood  of,  196;  comparison  of, 
with  blood  of  hepatic  vein,  198,  199;  its 
distribution  in  Liver,  368,  370. 

Pons  Varolii,  effects  of  section  of,  499. 

Potash,  its  predominance  in  red  corpuscles 
and  in  muscle,  176,  177;  effect  of,  on 
urine,  400,  401. 

Potteries  (Kensington),  mortality  at,  323, 
324. 

Pregnancy,  state  of  blood  in,  200,  201 ; 
signs  of,  771-773;  see  Gestation. 

Prehension  of  food,  movements  of,  86,  87. 

Presbyopia,  670,  671. 

Pressure  of  Blood,  in  heart,  255 ;  in  arte- 
ries, 263-265 ;  in  veins,  277,  288. 

Primitive  Trace,  787,  788. 

Prisons,  diet-scale  of,  71-73 ;  see  Gaols. 

Prognathous  Skull,  827-831. 

Projection  of  objects,  visual  appreciation  of, 
678-681. 

Prosencephalic  Vertebra,  804-806. 

Prosencephalon,  development  of,  787,  788, 
806,  807. 

Prostate  Gland,  function  of,  749,  750. 

Protracted  Gestation,  777,  778. 

Psychology,  Science  of,  its  objects,  539, 
540. 

Psychical  action,  correlation  of  with  Physio- 
logical action,  538,  539,  542-545;  see 
MIND. 

Ptyalin,  100,  102,  103,  104. 

Puberty,  the  characteristic  of  Youth,  859 ; 
in  female,  755 ;  in  male,  751,  752 ;  dis- 
eases of,  861. 

Puerperal  Fever,  predisposing  causes  of, 
223,  224. 

Pulse,  Arterial,  262-265;  rate  of,  under 
different  conditions,  255-258 ;  proportion 
of,  to  respiratory  movements,  290,  291. 

,  Respiratory,  276,  277. 

,  Venous,  250,  251. 

Pupil,  action  of,  484,  492,  494,  670,  675 . 
relation  of,  to  Third  Pair,  462,  note,  463, 
464 ;  to  Sympathetic,  675. 

Purpura,  state  of  blood  in,  201,  202. 

Pus,  formation,  on  characters  of,  347,  348 : 
influence  of,  on  coagulation  of  blood,  213. 


898 


INDEX    OF    SUBJECTS. 


Putrescent  Food,  injurious  consequences  of, 
74-76 ;  Water,  injurious  effects  of,  76. 

Pyramidal  Skull,  828,  829. 

Pyramids  of  Medulla  Oblongata,  anterior, 
456 ;  posterior,  458. 


Quadrumana,    comparison   of,    with    Man, 

34-43. 

Quagga,  transmission  of  marks  of,  781,  782. 
Quickening,  act  of,  772,  773. 


R. 


Races,  origination  of  new,  832,  833. 

Races  of  Mankind,  American,  836,  837; 
Arian  or  Indo-European,  836-839;  Ber- 
ber, 839;  Bushman,  844;  Caucasian,  836, 
837;  Celtic,  837-839;  Hindostanic,  840, 
841;  Hottentot,  844;  Kaffre,  843,  844; 
Mongolian,  839-841 ;  Malayo-Polynesian, 
846;  Negro,  842,  843;  Oceanic,  846; 
Pelagian-Negro,  847 ;  Seriform,  840,  841 ; 
Syro-Arabian,  839. 

Rapidity  of  Muscular  movements,  714-716. 

Rattle-snake,  poison  of,  secretion  after 
death,  866  note. 

Reasoning,  processes  of,  584. 

Reciprocation  of  sonorous  vibrations,  693 ; 
by  membrana  tympani,  696. 

Recollection,  583,  584,  587,  588. 

Red  Corpuscles,  see  Blood. 

Reeds,  vibrating,  laws  of,  772. 

Reflection,  mental  process  of,  581. 

Reflex  Actions,  general  nature  of,  61,  432 ; 
of  Spinal  Cord,  477,  486  (see  Excito-Motor 
Actions) ;  of  Sensory  Ganglia,  502-505 
(see  Sensori-Mntor  Actions) ;  of  Cerebrum, 
542,  543,  589  ^(see  Ideo-Motor  Actions, 
Automatic  Mental  Actions,  &c.). 

Refraction,  laws  of,  667,  668. 

Regeneration  of  tissues,  332-335. 

Regimen,  see  Diet,  Food. 

Relations,  near,  tendency  of  their  marriage 
to  produce  imperfect  progeny,  780. 

Relief,  of  surfaces,  visual  appreciation  of, 
678-C81 ;  conversion  of,  684,  685. 

Religious  Intuitions,  558. 

Reparation  of  injuries,  343 ;  completeness 
of,  in  lower  animals,  343 ;  limitations  of, 
in  higher,  343,  344 ;  most  energetic  and 
complete  in  earliest  periods  of  life,  344; 
not  dependent  on  inflammation,  344 ;  by 
immediate  union,  344 ;  by  adhesion,  345  ; 
by  modelling  process,  345-347 ;  by  sup- 
purative  granulation,  347,  348 ;  by  secon- 
dary adhesion,  348. 

Reproduction  of  limbs,  in  foatus,  343,  344 ; 
of  lower  jaw,  343,  344. 

Resonance  of  sounds,  693. 

RESPIRATION,  general  nature  of  the  func- 
tion, 54,  55 ;  sources  of  demand  for, 
280,  282 ;  essential  provisions  for,  280 ; 
apparatus  of,  282-288  (see  Lungs). 
Movements  of,  288,  289;  muscular  force 
required  for,  289,  290 ;  rate  and  extent 


of,  290,  291 ;  maintenance  of,  by  nervous 
system,  291-297 ;  excitor  nerves  of, 
292,  293:  motor  nerves  of,  292,  293; 
partial  volitional  control  over,  293,  294 ; 
modifications  of,  295,  296. 
Effects  of,  on  Air,  298-313;  amount  of 
air  consumed,  298-301 ;  changes  in  its 
proportions  of  oxygen  and  carbonic  acid, 
298-304 ;  quantity  of  carbonic  acid  im- 
parted to,  304-310;  changes  in  pro- 
portion of  nitrogen,  310 ;  watery  vapour 
imparted  to,  310-312  ;  absorption  from, 
312,  313. 

Effects   of,    on   Blood,   193-196;    on  its 
general  composition,   193;  on  its  free 
gases,   193;   on  its  fibrin,  193;  on  its 
corpuscles,  194;  on  its  colour,  196. 
Consequences  of  Suspension  of,  314-316. 
Effects  of  Deficiency  of,  316,317;  predis- 
position to  zymotic  disease,  317,  324; 
predisposition   to   spasmodic    diseases, 
324-326 ;  excess  of  mortality  attribut- 
able to,  326,  327. 

Respiration  of  hydrogen,  309,  313  ;  of  nitro- 
gen, 310,  313;  of  oxygen,  312,  313. 

artificial,  partial  sustenance  of 

heat  by,  415,  416. 
Respiratory  Pulse,  276,  277. 
Restiform  bodies,  456,  458. 
Retina,  structure  of,  671,  674;  most  sensi- 
tive point  of,  673 ;  least  sensitive  point 
of,  673,  688;  persistence  of  impressions 
on,  685,  686 ;  irradiation  of  impressions 
on,   687 ;   spectra  produced  by  pressure 
on,   688,   689 ;    circulation   in,    rendered 
visible,  689 ;  development  of,  808. 
Reverie,  state  of,  601. 
Rhinencephalic  Vertebra,  804,  806. 
Rhinencephalon,  development  of,  806,  807. 
Rhythmical  movements  of  heart,  241 ;  see 

Heart. 

Right,  sense  of,  557 ;  notion  of,  562-565. 
Rudimental  parts,  uses  of,  227. 


S. 


Saccharine  constituents  of  food,  63,  64,  67, 
68,  71;  digestion  of,  116,  117. 

matter  in  blood,  190,  197,  199. 

St.  Kilda,  mortality  at,  324,  326. 

St.  Martin,  case  of,  94,  108-113. 

Saliva;  composition  of,  100,  102 ;  different 
kinds  of,  102,  103;  uses  of,  103,  104; 
influence  of  nervous- system  on,  739,  740; 
quantity  secreted  daily,  103. 

Salivary  Glands,  100,  101. 

Salts,  Neutral,  influence  of,  on  change  of 
colour  of  blood,  195;  in  retarding  coagu- 
lation of  blood,  209,  211. 

of  Blood,  normal  proportion  of,  186, 

188,  199;  variations  of,  in  disease,  204, 
205 ;  uses  of,  225. 

of  Urine,  393,  397. 

Sanguification,  process  of,  150-168;  share 
of  Liver  in,  150,  151 ;  of  Absorbent  Sys- 
tem, 152-159  ;  Ductless  Glands,  159-168 

Sanskritic  languages,  837,  841. 


INDEX    OF    SUBJECTS. 


899 


Satiety,  sense  of,  71,  81  note. 

Scab,  formation  of,  345  ;  artificial,  347. 

Scurvy,  causes  of,  69,  70 ;  state  of  blood  in, 
201,  203  ;  at  Milbank,  85. 

Secondarily-Automatic  actions,  485,  486, 
504,  505. 

Secondarily-Intuitive  perceptions,  556. 

SECRETION,  general  nature  of,  54-56,  357 ; 
its  relation  to  Excretion,  358,  359;  in- 
fluence of  nervous  system  on,  739-743, 
744 ;  continuance  of,  after  death,  866 ; 
metastasis  of,  363,  365 ;  electric  disturb- 
ance in,  422,  423  ;  see  Bile,  Gastric  Juice, 
Milk,  Pancreatic  Fluid,  Saliva,  Urine, 
&c. 

Secunderabad,  mortality  of  troops  at,  324. 

Segmentation  of  vitellus,  785,  786. 

Self-control,  see  Volition. 

Semicircular  Canals,  698,  699 ;  functions 
of,  698,  699;  effects  of  section  of,  497, 
498. 

Seminal  fluid,  characters  of,  749,  750. 

Semitic  Race,  839-843. 

Sensation,  its  seat  in  the  Sensorium,  495, 
496;  general,  649,  650;  special,  650; 
dependence  of,  on  capillary  circulation, 
650;  various  kinds  of,  650,  651;  excite- 
ment of,  by  electricity,  652 ;  by  mecha- 
nical impressions,  652. 

Sensations,  origin  of  all  mental  activity  in, 
545,  546 ;  their  seat  in  Sensory  Ganglia, 
495,  496;  registration  of,  545,  546;  in- 
fluence of  Attention  on,  546-548 ;  in- 
fluence of  Habit  on,  548,  549 ;  subjective 
origin  of,  549-553 ;  feelings  of  pain  and 
pleasure  connected  with,  549  ;  other  feel- 
ings associated  with,  553,  554. 

Sensibility,  general,  relative  degrees  of,  in 
different  parts  of  body,  649-652. 

— ,  tactile,  relative,  of  different  parts 
of  skin,  654. 

Sensori-motor  Actions,  61 ;  their  corres- 
pondence with  the  Instinctive  of  lower 
animals*  61,  433,  434,  their  independ- 
ence of  the  Cerebrum,  502,  503;  their 
establishment  by  habit,  504,  505 ;  their 
predominance  in  states  of  suspended 
Cerebral  activity,  635-640. 

Sensorium,  its  special  seat  in  the  Sensory 
Ganglia,  495,  496,  535,  536. 

Sensory  Ganglia,  general  structure  and  re- 
lations of,  437,  488-491;  their  nerves, 
491-495 ;  their  relative  predominance  in 
lower  animals,  433-438 ;  the  probable 
seat  of  Sensation  for  external  impres- 
sions, 495,  496  (see  Sensations) ;  also  for 
Cerebral  changes,  535,  536;  reflex  func- 
tions of,  502,  503  (see  Sensori-motor 
Actions)  ;  their  participation  in  voluntary 
actions,  505-511;  independent  activity 
of,  635,  646;  pathological  relations  of, 
646-648. 

Sensory  Nerves,  laws  of  transmission 
through,  443,  444;  see  Afferent  Nerve- 
fibres. 

Sensory  Tract  of  Medulla  Oblongata,  458- 
461. 


Seriform  Race,  840,  841. 

Serous  layer  of  Germinal  membrane,  786, 
787. 

Serous  effusions  of  Inflammation,  352,  353. 

Serum,  172,  173,  208;  proportion  of,  to 
crassamentum,  213 ;  transudation  of,  352, 
353. 

Setter  and  Pointer,  peculiar  breeding  of, 
779,  780. 

Seventh  Pair  of  Nerves,  464,  465. 

Sexes,  proportional  number  of,  808;  dif- 
ferences in  general  development  of,  810, 
811 ;  in  viability,  808;  in  composition  of 
blood,  189,  190;  in  pulse,  255-258;  in 
respiration,  304,  305 ;  in  psychical  cha- 
racter, 813. 

Sexual  sensation,  probable  seat  of,  520- 
522. 

Shock,  effect  of,  on  heart,  242,  243;  on 
capillary  circulation,  275. 

Sighing,  act  of,  295. 

Similarity,  law  of,  576,  577. 

Single  Vision,  conditions  of,  677,  678,  712- 
714. 

Six-fingered  families,  832,  833. 

Sixth  Pair  of  Nerves,  463,  464. 

Size,  visual  appreciation  of,  682,  68S.  584. 

Sheep,  new  breeds  of,  832,  833. 

Skeleton,  development  of,  803-806. 

Skin,  Colour  of,  its  variation  in  Man,  825. 
826. 

,  Respiration  by,  307-309 ;  414,  415 ; 

transpiration  from,  401-405. 

Skull,  forms  of  in  different  Races,  827-831  - 
prognathous,  827,  828;  pyramidal,  828 
829 ;  oval,  829,  830. 

Sleep,  definition  of,  609,  610;  necessity  for 
611;  periodicity  of,  610,  611;  predis 
posing  influences  to,  611;  means  of  in 
ducing,  611 ;  access  of,  612,  intermediate 
states  between  sleeping  and  waking,  612, 
613;  influence  of  expectation  and  habit 
in  inducing,  613  ;  influence  of  impressions 
on  the  mind  of  the  sleeper,  613-622; 
amount  of,  required  by  man,  616;  cases 
of  absence  and  deficiency  of,  616;  undue 
protraction  of,  616. 

Smell,  ganglia  of,  489;  nerves  of,  481, 
482  ;  their  distribution,  665,  666  ;  Sense 
of,  665 ;  conditions  of,  667  ;  uses  of, 
665-667 ;  improvement  of,  667 ;  modifi- 
cation of,  by  habit,  667 ;  duration  of  im- 
pressions on,  667,  581,  582;  its  partici- 
pation in  Taste,  663,  664 ;  exaltation  of, 
in  Somnambulism,  619,  620. 

Sneezing,  act  of,  296. 

Sobbing,  act  of,  295. 

Solar  plexus  of  Sympathetic,  739,  740. 

Solidity,  perception  of,  678-681. 

Somatic  Death,  864-868. 

Somnambulism,  relations  of  to  sleep  ana 
reverie,  618,  627;  suspension  of  volitional 
control  in,  618;  phenomena  of,  618- 
620 ;  mesmeric,  620-622. 

Sounds,  propagation  of  693,  694;  direction 
of,  698,  704;  distance,  704,  705;  pitch 
of.  699. 


900 


INDEX    OF    SUBJECTS. 


Sounds  of  Heart,  251-253. 

Spasmodic    Disorders,    affection    of    Spinal 

Cord  in,  647,  648. 
Specific    identity    or    diversity   of    Human 

Races,  question  of,  824,  836. 
Spectral  illusions,  641,  642. 
Spermatozoa,  nature  and  evolution  of,  750, 
751  ;    essential  importance   of,  in  fecun- 
dation, 751,  752,  763,  764. 
Spheno-palatine   ganglion   of  Sympathetic, 

735,  736. 

Spherical  Aberration,  668. 
Sphincters,    action   of,   99,    100,   482,   483, 

487,  488. 

Spinal- Accessory  Nerve,  distribution  and 
functions  of,  468,  469. 

Cord,    Structure   of,    448-455 ;    ex- 
ternal conformation  of,  448-450 ;  vesi- 
cular  substance  of,   448-451 ;    fibrous 
strands    of,    448-451 ;    connection    of, 
•with  nerve  roots,  451-455. 
Functions   of,    472-488;    its    conducting 
power,  472-477 ;    relative  endowments 
of  its  anterior  and  posterior  columns, 
473-477;    its    proper    reflex    actions, 
477-482 ;  their  relation  to  the  Organic 
functions,    482,   483 ;    their   protective 
character,  483-485  ;  their  subservience 
to   locomotion,  485-487;    its  influence 
on  Muscular  tension,  487,  488. 
Abnormal   actions   of,  644-648 ;    general 
suspension  of  power  of,  644 ;  excessive 
excitability    of,    in    Tetanus,    645 ;    in 
Hydrophobia,    645 ;    in    Hysteria,  645, 
646 ;    partial    excitability  of,  in   Spas- 
modic  diseases,  647,  648:  partial  loss 
of  power  of,  in  Paralysis,  648. 
Spinal    Nerves,    461 ;    double   function    of 
their  roots,  442,  446,  447 ;  their  connec- 
tion with  the  Spinal  Cord,  451-454. 
Spiritualist  hypothesis,  447-452. 
Spitalfields  Workhouse,  fever,  &c.,  at,  323. 
Spleen,    structure    of,    159-161 ;    develop- 
ment of,  161,  162;  functions  of,  165-168; 
blood  of,  197,  198. 
Splenic  Blood,  197,  198. 
Stammering,  nature  of,  731 ;  treatment  of, 

732. 

Stapedius,  functions  of,  695,  696. 
Starch,  a  constituent   of  food,  63,  65,  71 ; 
its  transformation  by  saliva,  103,  104;  by 
intestinal  fluid,  127,  128. 
Starvation,  effects  of,  83-86 ;  death  by,  83, 
867  ;    Chossat's  experiments  on,  82,  83, 
413,  414. 

Stereoscope,  679-685. 

Stomach,  movements  of,  94,  95 ;  action  of, 
in  vomiting,  96,  97 ;  influence  of  pneu- 
mogastric  oil,  95,  96 ;  secreting  follicles 
of,  104-108;  villi  of,  108;  secretion  of, 
110-115:  digestion  in,  115-120;  effects 
of  blows  on,  244. 

Strabismus,  pathology  of,  712-714. 
Strangury,  647,  648. 
Strength,  feats  of,  714,  715. 
String,  vibrating,  laws  of,  721,  722. 
Strychnia,  artificial  tetanus  of,  644,  645. 


Subjective  Sensations,  544-550;  origin  of, 
550-553. 

Sublingual  Gland,  100:  secretion  of,  102, 
103. 

Submaxillary  Ganglion  of  Sympathetic, 
736. 

Submaxillary  Gland,  100-102  note;  secre- 
tion of,  100-103. 

Succus  Entericus,  127  ;  its  use  in  digestion, 
127,  128. 

Suction,  act  of,  86,  87. 

Sudoriparous  Excretion,  composition  of, 
401-403:  quantity  of,  403,  404:  vica- 
rious with  urinary,  404 ;  consequences  of 
suppression  of,  405;  frigorifying  effect 
of,  379-381. 

Sudoriparous  Glandules,  401,  402. 

Sugar,  formation  of,  in  liver,  150,  199; 
372-374,  381 ;  passage  of,  into  urine, 
150,  399  note. 

Suggestion,  influence  of,  in  determining 
succession  of  thought,  575,  583. 

Sulphates,  Alkaline,  in  urine,  394-396. 

Sulphur  of  Bile,  its  elimination  by  faeces, 
131,  360-362. 

,  in  extractive  of  Urine,  393,  394. 

Superfostation,  778,  779. 

Supernumerary  Parts.  340. 

Suppuration  of  wounds,  347,  348. 

Supra-Renal  bodies,  structure  of,  162,  168; 
development  of,  163;  function  of,  165, 
166. 

Surgical  Fever,  predisposing  causes  of,  233, 
234. 

Symmetrical  diseases,  226,  227. 

Sympathetic  System,  see  NERVOUS  SYSTEM. 

Syncope,  640,'  641 ;  death  by,  866,  867. 

Syro- Arabian  Race,  839,  840. 

Swallowing,  act  of,  90-93. 

T. 

Table-Talking,  595,  596. 

Table-Turning,  594,  595. 

Tactile  Corpuscles,  652-654. 

Tamulian  Language,  840,  841. 

Taste,  ganglion  of,  488,  489 ;  nerves  of, 
465,  466;  Sense  of,  658,  659;  peculiar 
objects  of,  658,  659 ;  special  conditions 
of,  659;  seat  of,  660-663;  papillae  of, 
660-663  ;  varying  acuteness  of,  663  ;  par- 
ticipation of  smell  in,  663,  664 ;  uses  of, 
664;  improvement  of,  by  habit,  664; 
cases  of  loss  of,  664  note. 

Taunton,  Cholera  at,  317,  318. 

Tea,  influence  of,  on  urine,  399,  400. 

Teeth,  deciduous,  exuviation  of,  337 ;  de- 
velopment of,  853-855 ;  permanent,  de- 
velopment of  855-858. 

Temperature,  external,  influence  of,  on  tem- 
perature of  body,  406-409 ;  extremes  of, 
endured  by  Man,  410-412. 

Sense  of,  655,  656 

Tenesmus,  647,  648. 

Tension  of  Muscles,  influence  of  Spinal 
Cord  on,  487,  488. 

Tensor  tympani,  functions  of,  695,  696. 


INDEX    OF    SUBJECTS. 


901 


Testes,  structure  of,  748,  749;  development 
of,  800,  801. 

Tetanus,  pathology  of,  644,  645. 

Thalaini  Optici,  489,  490 ;  their  relation  to 
Cerebrum,  490,  525;  their  functions, 
498,  499. 

Theine,  effect  of,  on  urine,  399,  400. 

Third  Pair  of  Nerves,  463,  464. 

Thirst,  indicates  necessity  for  liquid,  52 ; 
immediate  source  of  sense  of,  80,  81. 

Thyrnus  Gland,  structure  and  development 
of,  163-165;  function  of,  165;  166. 

Thyroid  Gland,  structure  of,  165;  function 
of,  165,  166. 

Tongue,  papilloe  of,  660-663 ;  sensory 
nerves  of,  464-466 ;  motor  nerves  of, 
469,  470. 

Tongues,  vibrating,  laws  of,  722,  723.. 

Tonicity  of  Arteries,  278,  279 ;  of  veins, 
277,  278. 

Touch,  ganglia  of,  489,  490 ;  nerves  of,  495 ; 
Sense  of,  650-655  ;  papillae  of,  652-654 ; 
varying  acuteness  of,  654;  knowledge 
acquired  by,  655-658 ;  improvement  of, 
by  practice  and  attention,  657,  658 ;  com- 
bination of,  with  visual  sense,  676. 

Toxic  Diseases,  general  pathology  and  the- 
rapeutics, of,  232-239. 

Trainers,  diet  of,  73-76. 

Trance,  cases  of,  868,  869. 

Tricuspid  valve,  imperfect  closure  of,  250, 
251. 

Trigeminus,  see  Fifth  Pair. 

Trismus  Nascentium,  mortality  from,  324- 
326. 

Truth,  notion  of,  562,  563. 

Tuber  Annulare,  effects  of  section  of,  500- 
502  ;  effects  of  electric  current  on,  499. 

Tubercle,  nature  of,  355,  356. 

Tubercula  Quadrigemina,  488,  489,  497. 

Tubercular  Diathesis,  355,  356  ;  manifesta- 
tion of,  at  different  ages,  860,  861. 

Tumours,  their  relation  to  hypertrophies, 
339-341  ;  malignant,  356,  357. 

Turkish  Race,  840,  841. 

Tympanic  apparatus,  structure  and  uses  of, 
694-696. 

Typhoid  fever,  alterations  of  blood  in,  201, 
202. 


U. 

Umbilical  Cord,  structure  of,  791,  79*. 

Vesicle,  788-791. 

Vessels,  791-795. 

Unconscious  Cerebration,  587—590. 

Uraclius,  790,  791. 

Uraemia,  pathology  of,  388,  389. 

Urea,  its  ordinary  proportion  in  urine, 
389-392 ;  sources  of,  384-393 ;  variations 
of,  389-392,  397,  398,  400,  401 ;  conse- 
quences of  its  non-elimination,  388,  389  ; 
its  presence  in  sweat,  402-404. 

Uric  Acid,  its  ordinary  proportion  in  urine, 
389-392 ;  its  sources,  384-393  ;  variations 
in  its  amount,  392,  393,  397,  398 ;  sedi- 
ments produced  by,  393. 


Urination,  act  of,  99,  482,  483. 

Urine,  secretion  of,  385,  386 ;  excrementi- 
tious  character  of,  359-364,  378,  388, 
397-390;  physical  properties  of,  389,  390; 
quantity  of,  389,  390 ;  specific  gravity  of, 
389,  390 ;  composition  of,  389,  390  ;  differ- 
ences of,  with  age,  891,  392  ;  influence  of 
diet  on,  397-400 ;  influence  of  diuretic 
medicines  on,  400,  401 ;  Organic  compo- 
nents of,  389-394  (see  Urea,  Uric  Acid, 
&c.);  acidity  of,  397-412;  alkalinity  of, 
396,  397 ;  Inorganic  components  of,  394, 
397 ;  sugar  in,  399 ;  lactic  acid  in,  398, 
399  ;  vicarious  secretion  of,  363-365 :  in- 
continence of,  647,  648. 

Uro-genital  sinus,  798,  802 

Uterine  Glandulse,  800,  801. 

Uterus,  inherent  motility  of,  245,  246;  in- 
crease of,  during  pregnancy,  772,  773  ; 
action  of.  in  parturition,  773,  774;  sub- 
sequent degeneration  of,  335,  336,  774 ; 
embryonic  development  of,  800,  801 ;  ru- 
dimentary, of  male,  801,  802. 


V. 


Valves  of  Heart,  249,  250;  difference  of 
mitral  and  tricuspid,  250,  251 ;  sounds 
produced  by  tension  of,  252,  253. 

Vapour,  aqueous,  absorption  of,  148,  312 ; 
exhalation  of,  310-312. 

Variation,  tendency  to,  831,  832. 

Varieties  of  Man,  their  essential  conformity 
in  structure,  824-833;  in  physiological 
characters,  833,  834  ;  in  psychical  endow- 

•     ments,  835;  in  languages,  836;  see  Races. 

Vasa  lutea,  789  note. 

Vascular  Area,  788,  789. 

Lamina  of  Germinal  membrane, 

787,  788. 

Vegetables,  fresh,  an  essential  article  of 
diet,  69,  70. 

Vegetarianism,  67,  68. 

Veins,  structure  of,  275,  276 ;  movement  of 
blood  in,  276-278:  causes  of  motion  of 
blood  in,  276,  277 ;  congestion  in,  277, 
278. 

Venous  Blood,  differential  characters  of, 
193-196. 

Vertebra,  typical,  803,  804. 

Vertebrae,  cranial,  804-806. 

Vertebral  Column,  first  indications  of,  786- 
*  88 ;  subsequent  development  of,  803, 804. 

Vertigo,  642. 

Vesicula  Prostatiea,  its  real  import,  800, 
892  note. 

Vesiculse  Seminales,  function  of,  749,  750. 

Vesicular  nerve-substance,  343-345. 

Vestibule  of  Ear,  698,  699. 

Viability,  early,  of  foetus,  776,777;  relative, 
of  two  Sexes,  811,  812. 

Villi,  intestinal,  structure  of,  133-139;  of 
stomach,  104-108. 

Vision,  ganglia  of,  488,  489 ;  nerves  of,  491- 
494 ;  "Sense  of,  667-670 ;  objects  of,  674, 
675;  optical  conditions  of,  667-670;  de- 
fects in,  670,  671 ;  nervous  apparatus  of. 


902 


INDEX    OF    SUBJECTS. 


670-675 ;  limits  of,  675 ;  use  of,  in  com- 
bination with  touch,  676 ;  erect,  cause  of, 
677;  single,  conditions  of,  677,  712-714; 
appreciation  of  solid  forms  by,  678-681 ; 
of  distances,  681,  682;  of  size,  682-684; 
conversions  of  relief,  684, 685 ;  persistence 
of  impressions,  685,  686 ;  complementary 
colours,  686,  687 ;  want  of  power  to  dis- 
tinguish colours,  687,  688 ;  irradiation  of 
impressions,  688 ;  vanishing  of  images, 
688,  689 ;  subjective  phenomena  of,  688, 
689 ;  representation  of  retina  itself,  689  ; 
improvement  of,  by  attention,  690 ;  im- 
portance of,  in  guiding  movement,  507, 
508. 

Vitelline  Duct,  789-791. 

Vessels,  789. 

\ritellus,  753,  754 ;  its  segmentation,  786. 

Voice,  ordinary,  mode  of  production,  721- 
723 ;  falsetto,  725,  726. 

Volition,  universal  consciousness  of  its  na- 
ture and  exercise,  543,  544;  limitations 
to  its  action,  573,  585,  586,  587 ;  its  in- 
fluence on  Muscular  movement,  597-599  ; 
aifections  of,  by  Emotions,  570-572 ;  its 
influence  in  directing  current  of  Thought, 
573,  574,  584,  585,  599,  600 ;  fixation  of 
Attention  by,  599,  600 ;  effects  of  its  sus- 
pension, 600,  601 ;  in  states  of  Reverie, 
Abstraction,  and  Electro-Biology, 601-604; 
in  states  of  Dreaming  and  Somnambulism, 
616-620;  relation  of,  to  external  impres- 
sions, 603-605 ;  to  Habits  of  thought,  604, 
606,  607 ;  to  motives,  606,  607  ;  gradual 
acquirement  of  power  of,  608 ;  highest 
and  lowest  uses  of,  608,  609 ;  deficiency 
of,  in  Abnormal  mental  states,  625,  626. 

Volitional  Actions,  597,  598;  their  source  in 
the  Cerebrum,  535,  536 ;  distinctness  of 
their  origin  from  Emotional,  568,  569 ; 
affection  of,  by  Emotions,  572 ;  power  of, 
dependent  on  concentration  of  purpose, 
697,  598. 


Voluntary  Movements,  their  dependence  on 
guiding  sensations,  505-508 ;  performed 
by  instrumentality  of  Sensori-Motor  ap- 
paratus, 508-511,  707,  708;  not  in  them- 
selves distinguishable  from  involuntary 
movements,  707 ;  but  result  from  an  im- 
pulse originating  in  Cerebrum,  535,  536. 

Vomiting,  act  of,"  96,  97. 

Vowel  sounds,  727-729. 


W. 


Wandsworth,  Cholera  at,  319,  320. 

Water,  the  natural  drink  of  Man,  76,  77 ; 
effects  of  impurity  of,  76,  77  ;  normal  pro- 
portion of,  in  Blood,  185, 186,  199  ;  alter- 
ations in,  190-205;  transudation  of,  by 
Kidney,  385,  386. 

Water-dressing  of  wounds,  346,  347. 

White  Corpuscles,  see  Mood,  Colourless  Cor- 
puscles. 

Will,  see  Volition. 

Y. 

Yawning,  act  of,  295 ;  consensual  suggestion 
of,  295. 

Yellow  Spot  of  Retina,  673,  674. 

Youth,  characteristics  of,  859,  860. 

Yellow-Fever,  elevation  of  temperature  after 
death  from,  409,  410;  continuance  of  ca- 
pillary circulation,  270,  271 ;  immunity 
of  Negroes  from,  834  note. 


Z. 


Zona  pellucida,  754,  755. 

Zymotic  poisons,  233,  234 ;  predisposition  to 
their  activity  from  state  of  blood,  235,  236 ; 
from  putrescent  food,  74-76;  from  pu- 
trescent  water,  76,  77 ;  from  alcoholic 
liquors,  78-80 ;  from  starvation,  83,  84 ; 
from  deficiency  of  respiration,  317-324. 


IBB   END 


' 


C. 

(LATE  LEA  k  BLANCHARD'S) 

TJIE 


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will  be  Three  Dollars  and  a  Haifa  year,  in  advance,  containing  in  all  nearly  a  thou- 
sand pages  per  annum. 

As  stated  above,  however,  they  will  be  supplied  in  conjunction  with  the  "AMERICAN 
JOURNAL  OF  THE  MEDICAL  SCIENCES,"  making  in  all  about  TWENTY-ONE  HUNDRED  pages 
per  annum,  the  whole  free  of  postage,  for  Six  DOLLARS  a  year,  in  advance. 

As  the  January  volume  of  the  "  HALF-YEARLY  ABSTRACT"  has  supplied  to  subscri- 
bers what  is  due  to  them  for  half  of  the  year  1874,  the  Supplement  to  the  Nejvs  and 
Library  will  be  commenced  with  July,  1874. 

In  this  effort  to  bring  so  large  an  amount  of  practical  information  within  the  reach 
of  every  member  of  the  profession,  the  publisher  confidently  anticipates  the  friendly 
aid  of  all  who  are  interested  in  the  dissemination  of  sound  medical  literature.  He 
trusts,  especially,  that  the  subscribers  to  the  "AMERICAN  MEDICAL  JOURNAL"  will  call 
the  attention  of  their  acquaintances  to  the  advantages  thus  offered,  and  that  be  w'ill 
be  sustained  in  the  endeavor  to  permanently  establish  medical  periodical  literature  on 
a  footing  of  cheapness  never  heretofore  attempted. 

PREMIUM  FOR  NEW  SUBSCRIBERS. 

Any  gentleman  who  will  remit  the  amount  for  two  subscriptions  for  1874,  one  of 
which  must  be  for  a  new  subscriber,  will  receive  as  a  PREMIUM,  free  by  mail,  a  copy  of 
STURGES'  CLINICAL  MEDICINE  (for  advertisement  of  which  see  p.  14),  or  of  the  new  edi- 
tion of  SWAYKE'S  OBSTKTIUC  APHORISMS  (see  p.  24),  or  of  TANNER'S  CLINICAL  MANUAL 
(see  p.  5),  or  of  CHAMBERS'  RESTORATIVE  MEDICINE  (see  p.  15),  or  of  WEST  ON  NERV- 
OUS DISORDERS  OF  CHILDREN  (see  p.*21). 

*#*  Gentlemen  desiring  to  avail  themselves  of  the  advantages  thus  offered  will  do 
well  to  forward  their  subscriptions  at  an  early  day,  in  order  to  insure  the  receipt  of 
complete  sets  for  the  year  1874,  as  the  constant  increase  in  the  subscription  list  almost 
always  exhausts  the  quantity  printed  shortly  after  publication. 

d£gr  The  safest  mode  of  remittance  is  by  bank  check  or  postal  money  order,  drawn 
to  the  order  of  the  undersigned.  Where  these  are  not  accessible,  remittances  for  the 
"JOURNAL"  may  be  made  at  the  risk  of  the  publisher,  by  forwarding  in  REGISTERED 
letters.  Address, 

HENRY  0.  LEA, 
Nos.  706  and  708  SANSOM  ST.,  PHILADELPHIA  PA 


HENRY  C.  LEA'S  PUBLICATIONS — (Dictionaries). 


TJUNGLISON  (ROBLEY},  M.D., 

Late  Professor  of  Institutes  of  Medicine  in  Jefferson  Medical  College,  Philadelphia. 

MEDICAL  LEXICON;  A  DICTIONARY  OP  MEDICAL  SCIENCE:  Con- 
taining a  concise  explanation  of  the  various  Subjects  and  Terms  of  Anatomy,  Physiology, 
Pathology,  Hygiene,  Therapeutics,  Pharmacology,  Pharmacy,  Surgery,  Obstetrics,  Medical 
Jurisprudence,  and  Dentistry.  Notices  of  Climate  and  of  Mineral  Waters;  Formulae  for 
Officinal,  Empirical,  and  Dietetic  Preparations;  with  the  Accentuation  and  Etymology  of 
the  Terms,  and  the  French  and  other  Synonymes ;  so  as  to  constitute  a  French  as  well  as 
English  Medical  Lexicon.  A  New  Edition.  Thoroughly  Revised,  and  very  greatly  Mod- 
ified and  Augmented  By  RICHARD  J.  DUNGLISON,  M.D.  In  one  very  large  and  hand- 
some royal  octavo  volume  of  over  1100  pages.  Cloth,  $6  50  ;  leather,  raised  bands,  $7  50. 
(Just  Ready.} 

The  object  of  the  author  from  the  outset  has  not  been  to  make  the  work  a  mere  lexicon  or 
dictionary  of  terms,  but  to  afford,  under  each,  a  condensed  view  of  its  various  medical  relations, 
and  thus  to  render  the  work  an  epitome  of  the  existing  condition  of  medical  science.  Starting 
with  this  view,  the  immense  demand  which  has  existed  for  the  work  has  enabled  him,  in  repeated 
revisions,  to  augment  its  completeness  and  usefulness,  until  at  length  it  has  attained  the  position 
of  a  recognized  and  standard  authority  wherever  the  language  is  spoken. 

Special  pains  have  been  taken  in  the  preparation  of  the  present  edition  to  maintain  this  en- 
viable reputation.  During  the  t<  n  years  which  have  elapsed  since  the  last  revision,  the  additior  s 
to  the  nomenclature  of  the  medical  sciences  have  been  greater  than  perhaps  in  any  similar  period 
of  the  past,  and  up  to  the  time  of  his  death  the  author  labored  assiduously  to  incorporate  every- 
thing requiring  the  attention  of  the  student  or  practi  ioner.  Since  then,  the  editor  has  been 
equally  industrious,  so  that  the  additions  to  the  vocabulary  are  more  numerous  than  in  any  pre- 
vious revision.  Especial  attention  has  been  bestowed  on  the  accentuation,  which  will  be  found 
marked  on  every  word.  The  typographical  arrangement  has  been  much  improved,  rendering 
reference  much  more  easy,  and  every  care  has  been  taken  with  the  mechanical  execution.  The 
work  has  been  printed  on  new  type,  small  but  exceedingly  clear,  with  an  enlarged  page,  so  that 
the  additions  have  been  incorporated  with  an  increase  of  but  little  over  a  hundred  pages,  and 
the  volume  now  contains  the  matter  of  at  least  four  ordinary  octavos. 

A  book  well  known  to  our  readers,  and  of  which 
every  American  ought  to  be  proud.    When  the  learned 


author  of  the  work  passed  away,  probably  all  of  us 
feared  lest  the  book  should  not  maintain  its  place 
in  the  advancing  science  who?e  terms  it  defines.  For- 
tunately. Dr.  Richard  J.  Dunglison.  having  assisted  his 
father  in  tl$e  revision  of  several  editions  of  the  work, 
and  having  been,  therefore,  trained  in  the  methods  and 
imbued  with  the  spirit  of  the  book,  has  been  able  to 
edit  it,  not  in  the  patchwork  manner  so  dear  to  the 
heart  of  book  editors,  so  repulsive  to  the  taste  of  intel- 
ligent book  readers,  but  to  edit  ft  as  a  work  of  the  kind 
should  be  edited — to  carry  it  on  steadily,  without  jar 
or  interruption,  along  the  grooves  of  thought  it  has 
travelled  during  its  lifetime.  To  show  the  magnitude 
of  the  task  which  Dr  Dunglison  has  assumed  and  car- 
ried through,  it  is  only  necessary  to  stale  that  more 
than  six  thousand  new  subjects  have  been  added  in  the 
present  edition.  Without  occupying  more  space  with  ihe 
theme,  we  congratulate  the  editor  on  the  successful 
completion  of  his  labors,  and  hope  he  may  reap  the  well- 
earned  reward  of  profit  and  honor. — Plnla.  Med.  Times, 
Jan.  3,  1874. 

»  About  the  first  book  purchased  by  the  medical  stu- 
dent is  the  Medical  Dictionary.  The  lexicon  explana- 
tory of  technical  terms  is  simply  a  sine  qua  non.  In  a 
science  so  extensive,  and  with  such  collaterals  as  medi- 
cine, it  is  as  much  a  necessity  also  to  the  practising 
physician.  To  meet  the  wants  of  students  and  most 
physicians,  the  dictionary  must  be  condensed  while 
comprehensive,  and  practical  while  perspicacious.  It 
was  because  Dunglison's  met  these  indications  that  it 
became  at  once  the  dictionary  of  general  use  wherever 
medicine  was  studied  in  the  English  language.  In  no 
former  revision  have  the  alterations  and  additions  been 
so  great.  More  than  six  thousand  new  subjects  and  terms 
have  been  added.  The  chief  terms  have  been  set  in  black 
letter,  while  the  derivatives  follow  in  small  caps:  an 
arrangement  which  greatly  facilitates  reference.  We 
may  pafely  confirm  the  hope  ventured  by  the  editor 
"  that  the  work,  which  possesses  fur  him  a  filial  as  well 
a«  an  individual  interest,  will  be  found  worthy  a  con- 
tinuance of  the  position  so  long  accorded  to  it  as  a 
standard  authority." — Cincinnati  Clinic,  Jan.  10,  1874. 


We  are  glad  to  see  a  new  edition  of  this  invaluable 
work,  and  to  find  that  it  has  been  so  thoroughly  revised, 
nnd  so  greatly  improved.  The  dictionary,  in  its  pre- 
sent form,  is  a  nn  dical  library  in  itself,  and  one  of 
which  every  physician  should  be  possessed. — N.  Y.  Med. 
Journal,  i'eb.  1874. 

WTith  a  history  of  forty  years  of  unexampled  success 
and  universal  indorsement  by  the  medical  profession  of 
the  western  continent,  it  would  be  presumption  in  any 
living  medical  American  to  essay  its  review.  No  re- 
viewer, however  able,  can  add  to  its  fame ;  no  captious 
critic,  however  caustic,  can  remove  a  single  stone  from 
its  firm  and  enduring  foundation.  It  is  destined,  as  a 
colossal  monument,  to  perpetuate  the  solid  and  richly 
deserved  fame  of  Robley  Dunglison  to  coming  genera- 
tions. The  large  additions  made  to  the  vocabulary,  we 
think,  will  be  welcomed  by  the  profession  as  supplying 
the  want  of  a  lexicon  fully  up  with  the  march  of  sci- 
ence, which  has  been  increasingly  felt  for  some  years 
past.  The  accentuation  of  terms  is  very  complete,  and, 
as  far  as  we  have  been  able  to  examine  it,  very  excel- 
lent. We  hope  it  may  be  the  means  of  securing  greater 
uniformity  of  pronunciation  among  medical  men. — At- 
lanta Med.  and  Surg.  Joum.,  J)'eb.  1874. 

It  would  be  mere  waste  of  words  in  us  to  express 
>nr  admiration  of  a  work  which  is  so  universally 
and  "deservedly  appreciated.  The  most  admirable 
work  of  its  kind  in  the  English  language. —  Glasgow 
Medical  Journal,  January,  1866. 

A  work  to  which  there  is  no  equal  in  the  English 
language. — Edinburgh  Medical  Journal. 

Few  works  of  the  class  ex  hi  bit  a  grander  monument 
jf  patient  research  and  of  scientific  lore.  The  extent 
of  the  sale  of  this  lexicon  is  sufficient  to  testify  to  its 
usefulness,  and  to  the  great  service  conferred  by  Dr. 
Robley  Dunglison  on  the  profession,  and  indeed  on 
,  by  its  issue. — London  Lancet,  May  13,  1865. 

It  has  the  rare  merit  that  it  certainly  has  no  rival 
in  the  English  language  for  accuracy  and  extent  o/ 
references — London  Medical  Gazette. 


TJOBLYN  (RICHARD  D.),  M.D. 

A  DICTIONARY  OF  THE  TERMS  USED  IN  MEDICINE  AND 

THE  COLLATERAL  SCIENCES.     Revised,  with  numerous  additions,  by  ISAAC   HAYS, 
M.D.,  Editor  of  the  "American  Journal  of  the  Medical  Sciences."     In  one  large  royal 
12mo.  volume  of  over  500  double-columned  pages  ;  extra  cloth,  $1  50  ;  leather,  $2  00. 
It  is  the  best  book  of  definitions  we  have,  and  ought  always  to  be  apon  the  atndent'8  table. — Soutktrn 
Mtd.  and  Surg.  Journal. 


HENRY  (J.  LEA'S  PUBLICATIONS — (Manuals). 


\TEILL  (JOHN),  M.D., 


and 


RMITH  (FRANCIS  G.),  M.D., 

**-*     Prof,  of  the  Institutes  of  Medicine  in  the  Univ.  of  Penna. 

AN    ANALYTICAL    COMPENDIUM   OF   THE    VARIOUS 

BRANCHES  OF  MEDICAL  SCIENCE;  for  the  Use  and  Examination  of  Students.     A 

new  edition,  revised  and  improved.    In  one  very  large  and  handsomely  printed  royal  12mo. 

volume,  of  about  one  thousand  pages,  with  374  wood  cuts,  extra  cloth,  $4 ;  strongly  bound 

in  leather,  with  raised  bands,  $4  75. 

e  Compend  of  Drs.  Neilland  Smith  is  incompara- 1  cious  factstreasnredup  in  this  little  volume.  Acom- 
bly  the  most  valuable  work  of  its  class  ever  published  i  plete  portable  library  so  condensed  that  the  student 
In  this  country.  Attempts  have  been  made  in  various  may  make  it  his  constant  pocket  companion. —  West' 


Th 


quarters  to  squeeze  Anatomy,  Physiology,  Surgery, 
the  Practice  of  Medicine,  Obstetrics,  Materia  Medica, 
and  Chemistry  into  a  single  manual;  but  the  opera- 
tion has  signally  failed  in  the  hands  of  all  up  to  the 
advent  of  "  Neill  and  Smith's"  volume,  which  is  quite 
a  miracle  of  success.  The  outlines  of  the  whole  are 
admirably  drawn  and  illustrated,  and  the  authors 
are  eminently  entitled  to  the  grateful  consideration 
of  the  student  of  every  class. — N.  0.  Med.  and  Surg. 
Journal. 

There  are  but  few  students  or  practitioners  of  me- 
dicine unacquainted  with  the  former  editions  of  this 


ern  Lancet. 

In  the  rapid  course  of  lectures,  where  work  for  the 
students  is  heavy,  and  review  necessary  for  an  exa- 
mination, a  compend  is  not  only  valuable,  but  it  is. 
almost  a  sine  qua  non.  The  one  before  us  is,  in  most 
of  the  divisions,  the  most  unexceptionable  of  all  books 
of  the  kind  that  we  know  of.  Of  course  it  is  useless 
for  us  to  recommend  it  to  all  last  course  students,  but 
there  is  a  class  to  whom  we  very  sincerely  commend 
this  cheap  book  as  worth  its  weight  iu  silver — that 
class  is  the  graduates  in  medicine  o/ more  than  tea 
years'  standing,  who  have  not  studied  medicine 


auassumiug" though  highly  instructive  work.  The  since.  They  will  perhaps  find  out  from  it  that  the 
whole  science  of  medicine  appears  to  have  been  sifted,  science  is  not  exactly  now  what  it  was  when  they 
as  the  gold-bearing  sands  of  El  Dorado,  and  the  pre-  \  left  it  off.— The  Stethoscope. 

TTARTSHORNE  (HENRY],  M.  D., 

Professor  of  Hygiene  in  the  University  of  Pennsylvania. 

A   CONSPECTUS    OF   THE    MEDICAL   SCIENCES;   containing 

Handbooks  on  Anatomy,  Physiology,  Chemistry,  Materia  Medica.,  Practical  Medicine, 
Surgery,  and  Obstetrics.  Second  Edition,  thoroughly  revised  and  improved.  In  one  large 
royal  12mo.  volume  of  more  than  1000  closely  printed  pages,  with  over  300  illustrations  on 
wood.  (Preparing.) 

The  favor  with  which  this  work  has  been  received  has  stimulated  the  author  in  its  revision  to 
render  it  in  every  way  fitted  to  meet  the  wants  of  the  student,  or  of  the  practitioner  desirous  to 
refresh  his  acquaintance  with  the  various  departments  of  medical  science.  The  various  sections  have 
been  brought  up  to  a  level  with  the  existing  knowledge  of  the  day,  while  preserving  the  condema 
tion  of  form  by  which  so  vast  an  accumulation  of  facts  have  been  brought  within  so  narrow  a 
compass. 

less  valuable  to  the  beginner.  Every  medical  student 
who  desires  a  reliable  refresher  to  his  memory  when 
the  pressure  of  lectures  and  other  college  work  crowds 
to  prevent  him  from  having  an  opportunity  to  drink 
deeper  in  the  larger  works,  will  find  this  one  of  the 
greatest  utility.  It  is  thoroughly  trustworthy  from 


This  work  is  a  remarkabl  y  complete  one  in  its  way, 
and  comes  nearer  to  our  idea  of  what  a  Conspectus 
should  be  than  any  we  have  yet  seen.  Prof.  Harts- 
home,  with  a  commendable  forethought,  intrusted 
the  preparation  of  many  of  the  chapters  on  special 
subjects  to  experts,  reserving  only  anatomy,  physio- 
logy, and  practice  of  medicine  to  himself.  As  a  result 
we  have  every  department  worked  up  to  the  latest 
date  and  in  a  refreshingly  concise  and  lucid  manner. 
There  are  an  immense  amount  of  illustrations  scat- 
tered throughout  the  work,  and  although  they  have 
often  been  seen  before  in  the  various  works  upon  gen- 
eral and  special  subjects,  yet  they  will  be  none  the 


beginning  to  end;  and  as  we  have  before  intimated, 
a  remarkably  truthful  outline  sketch  of  the  present 
state  of  medical  science.  We  could  hardly  expect  it 
should  be  otherwise,  however,  under  the  charge  of 
such  a  thorough  medical  scholar  as  the  author  has 
already  proved  himself  to  be. — N.  York  Med.  Record, 
March  15,  1869. 


J  UDLOW  (J.L.),  M.D. 

A    MANUAL   OF   EXAMINATIONS   upon   Anatomy,   Physiology, 

Surgery,  Practice  of  Medicine,  Obstetrics,  Materia  Medica,  Chemistry,  Pharmacy,  and 
Therapeutics.  To  which  is  added  a  Medical  Formulary.  Third  edition,  thoroughly  revised 
and  greatly  extended  and  enlarged.  With  370  illustrations.  In  one  handsome  royal 
12mo.  volume  of  816  large  pages,  extra  cloth,  $3  25;  leather,  $3  75. 

The  arrangement  of  this  volume  in  the  form  of  question  and  answer  renders  it  especially  suit- 
able for  the  office  examination  of  students,  and  for  those  preparing  for  graduation. 

/TANNER  (THOMAS  HAWKES},  M.  D.,  frc. 

L  A  MANUAL  OF  CLINICAL  MEDICINE  AND  PHYSICAL  DIAG- 

NOSIS.     Third  American  from  the  Second  London  Edition.     Revised  and  Enlarged  by 

TILBURY  Fox,  M.  D.,  Physician  to  the  Skin  Department  in  University  College  Hospital, 

<fcc.    In  one  neat  volume  small  12mo.,  of  about  375  pages,  extra  cloth.   $1  50.    (Just  Issued.) 

***  By  reference  to  the  "  Prospectus  of  Journal"  on  page  3,  it  will  be  seen  that  this  work  is 

offered  as  a  premium  for  procuring  new  subscribers  to  the  "AMERICAN  JOURNAL  OF  THE  MEDICAL 

Taken  as  a  whole,  it  is  the  most  compact  vade  me-  I  The  objections  commonly,  and  justly,  urged  againut 
cum  for  the  use  of  the  advanced  student  and  junior  !  the  general  run  of  "compends,"  "conspectuses,"  and 
»ractitioner  with  which  we  are  acquainted.— Boston  i  other  aids  to  indolence,  are  not  applicable  to  this  little 
Med.  and  Surg.  Journal,  Sept.  22,  1870.  volume,  which  contains  in  concise  phrase  just  those 


It  contains  so  much  that  is  valuable,  presented  in 
so  attractive  a  form,  that  it  can  hardly  be  spared 


The  addit 


in  the  presence  of  more  full  and  complete  works, 
idditions  made  to  the  volume  by  Mr.  Fox  very 


aterially  enhance  its  value,  and  almost  make  it  a 
Its  convenient  size  makes  it  a  valuable 


practical  details  that  are  of  most  use  in  daily  diag- 
nosis, but  which  the  young  practitioner  finds  it  diffi- 
cult to  carry  always  in  his  memory  without  some 
quickly  accessible  means  of  reference.  Altogether, 
the  book  is  one  which  we  can  heartily  commend  to 
those  who  have  not  opportunity  for  extensive  read- 


new  work.     Its  convenien  'JTf  ™        ing,  or  who,  having  read  much,  still  wish  an  occa- 

companion  to  the  country  practitioner    and  if    .on-        «       pract(ical  reminder.-^.  ¥.  Med.  Gazette,  NOT. 
stantly  carried  by  him,  would  often  render  him  good  i  ft 

gervice   and  relieve  many  a  doubt  and  perplexity  — 
Lavenworth  Med.  Herald,  July,  1870. 


HENRY  C.  LEA'S  PUBLICATIONS — (Anatomy). 


(HENRY),  F.R.S., 

Lecturer  on  Anatomy  at  St.  George's  Hospital,  London. 

ANATOMY,   DESCRIPTIVE    AND    SURGICAL.      The  Drawings  by 

H.  V.  CARTER,  M.  D.,  late  Demonstrator  on  Anatomy  at  St.  George's  Hospital ;  the  Dissec- 
tions jointly  by  the  AUTHOR  and  DR.  CARTER.  A  new  American,  from  the  fifth  enlarged 
and  improved  London  edition.  In  one  magnificent  imperial  octavo  volume,  of  nearly  900 
pages,  with  465  large  and  elaborate  engravings  on  wood.  Price  in  extra  cloth,  $6  00  . 
leather,  raised  bands,  $7  00.  (Just  Issued.) 

The  author  has  endeavored  in  this  work  to  cover  a  more  extended  range  of  subjects  than  is  cus- 
tomary in  the  ordinary  text-books,  by  giving  not  only  the  details  necessary  for  the  student,  but 
also  the  application  of  those  details  in  the  practice  of  medicine  and  surgery,  thus  rendering  it  both 
a  guide  for  the  learner,  and  an  admirable  work  of  reference  for  the  active  practitioner.  The  en 
gravings  form  a  special  feature  in  the  work,  many  of  them  being  the  size  of  nature,  nearly  all 
original,  and  having  the  names  of  the  various  parts  printed  on  the  body  of  the  cut,  in  place  of 
figures  of  reference,  with  descriptions  at  the  foot.  They  thus  form  a  complete  and  splendid  series, 
which  will  greatly  assist  the  student  in  obtaining  a  clear  idea  of  Anatomy,  and  will  also  serve  to 
refresh  the  memory  of  those  who  may  find  in  the  exigencies  of  practice  the  necessity  of  recalling 
the  details  of  the  dissecting  room;  while  combining,  as  it  does,  a  complete  Atlas  of  Anatomy,  with 
a  thorough  treatise  on  systematic,  descriptive,  and  applied  Anatomy,  the  work  will  be  found  of 
essential  use  to  all  physicians  who  receive  students  in  their  offices,  relieving  both  preceptor  and 
pupil  of  much  labor  in  laying  the  groundwork  of  a  thorough  medical  education. 

Notwithstanding  the  enlargement  of  this  edition,  it  has  been  kept  at  its  former  very  moderate 
price,  rendering  it  one  of  the  cheapest  works  now  before  the  profession. 


The  illustrations  are  beautifully  executed,  and  ren- 
der this  work  an  indispensable  adjunct  to  the  library 
of  the  surgeon.  This  remark  applies  with  great  force 
to  those  surgeons  practising  at  a  distance  from  our 
large  cities,  as  the  opportunity  of  refreshing  their 
memory  by  actual  dissection  is  not  always  attain- 
able.—Canada  Mad.  Journal,  Aug.  1870. 

The  work  is  too  well  known  and  appreciated  by  the 
profession  to  need  any  comment.  No  medical  man 
can  afford  to  be  without  it,  if  its  only  merit  were  to 
serve  as  a  reminder  of  that  which  so  soon  becomes 
forgotten,  when  not  called  into  frequent  use,  viz.,  the 
relations  and  names  of  the  complex  organism  of  the 
human  body.  The  present  edition  is  much  improved. 
—California  Med.  Gazette,  July,  1870. 

Gray's  Anatomy  has  been  so  long  the  standard  of 
perfection  with  every  student  of  anatomy,  that  we 
need  do  no  more  than  call  attention  to  the  improve- 
ment in  the  present  edition. — Detroit  Review  of  Med. 
and  Pharm.t  Aug.  1870. 


From  time  to  time,  as  successive  editions  have  ap- 
peared, we  have  had  much  pleasure  in  expressing 
the  general  judgment  of  the  wonderful  excellence  of 
Gray's  Anatomy. — Cincinnati  Lancet,  July,  1870. 

Altogether,  it  is  unquestionably  the  most  complete 
and  serviceable  text-book  in  anatomy  that  has  ever 
been  presented  to  the  student,  and  forms  a  striking 
contrast  to  the  dry  and  perplexing  volumes  on  the 
same  subject  through  which  their  predecessors  strug- 
gled in  days  gone  by. — N.  Y.  Med.  Record,  June  15, 
1870. 

To  commend  Gray's  Anatomy  to  the  medical  pro- 
fession is  almost  as  much  a  work  of  supererogation 
as  it  would  be  to  give  a  favorable  notice  of  the  Bible 
in  the  religious  press.  To  say  that  it  is  the  most 
complete  and  conveniently  arranged  text  book  of  its 
kind,  is  to  repeat  what  each  generation  of  students 
has  learned  as  a  tradition  of  the  elders,  and  verified 
by  personal  experience. — N.  Y.  Med.  Gazette,  Dec. 
17,  1870. 


VMITH  (HENRY H.),  M.D.,         and     TJORNER  (  WILL1A M  E.),  M.D., 

Prof,  of  Surgery  in  the  Univ.  of  Penna. ,  Ac.  Late  Prof,  of  Anatomy  in  the  Univ.  ofPenna. ,  Ac . 

AN    ANATOMICAL    ATLAS,  illustrative   of  the   Structure  of  the 

Human  Body.     In  one  volume,  large  imperial  octavo,  extra  cloth,  with  about  six  hundred 
and  fifty  beautiful  figures.     $4  50. 

The  plan  of  this  Atlas,  which  renders  it  so  pecu-  I  the  kind  that  has  yet  appeared;  and  we  must  add, 
liarly  convenient  for  the  student,  and  its  superb  ar-  |  the  very  beautiful  manner  in  which  it  is  "got  up," 
tistical  execution,  have  been  already  pointed  out.  We  j  is  so  creditable  to  the  country  as  to  be  flattering  to 
must  congratulate  the  student  upon  the  completion    our  national  pride. — American  MedicalJournal. 
of  this  Atlas,  as  it  is  the  most  convenient  work  of  I 

VHARPEY  (  WILLIAM),  MJ)~., ~a^d       7)UAIN  (JONES  fr  RICHARD). 
HUMAN  ANATOMY.   Revised,  with  Notes  and  Additions,  by  JOSEPH 

LEIDY,  M.D.,  Professor  of  Anatomy  in  the  University  of  Pennsylvania.     Complete  in  two 
large  octavo  volumes,  of  about  1300  pages,  with  511  illustrations;  extra  cloth,  $6  00. 
The  very  low  price  of  this  standard  work,  and  its  completeness  in  all  departments  of  the  subject, 
should  command  for  it  a  place  in  the  library  of  all  anatomical  students. 


JJODGES  (RICHARD  M.),  M.D., 

Late  Demonstrator  of  Anatomy  in  the  Medical  Department  of  Harvard  University. 

PRACTICAL  DISSECTIONS.     Second  Edition,  thoroughly  revised.     In 

one  neat  royal  12mo.  volume,  half-bound,  $2  00. 

The  object  of  this  work  is  to  present  to  the  anatomical  student  a  clear  and  concise  description 
of  that  which  he  is  expected  to  observe  in  an  ordinary  course  of  dissections.  The  author  has 
endeavored  to  omit  unnecessary  details,  and  to  present  the  subject  in  the  form  which  many  years' 
experience  has  shown  him  to  be  the  most  convenient  and  intelligible  to  the  student.  In  the 
revision  of  the  present  edition,  he  has  sedulously  labored  to  render  the  volume  more  worthy  of 
••he  favor  with  which  it  has  heretofore  been  received. 


HORNER'S  SPECIAL  ANATOMY  AND  HISTOLOGY.  |      in  2  vols.  Svo  ,  of  over  1000  pages,  with  more  tha- 
edition,  ext«tmively  revised  and  modified.  I      300  wood -cuts ;  extra  cloth.  *«  00. 


HENRY  C.  LEA'S  PUBLICATIONS — (Anatomy). 


7 


WILSON  (ERASMUS),  F.R.S. 

A  SYSTEM  OF  HUMAN  ANATOMY,  General  and  Special.     Edited 

by  W.  H.  GOBEECHT,  M.  D.,  Professor  of  Geuerahmd  Surgical  Anatomy  in  the  Medical  Col- 
lege of  Ohio,  illustrated  with  three  hundred  and  ninety-seven  engravings  on  wood.  In 
one  large  and  handsome  octavo  volume,  oi  over  600  large  pages;  extra  cloth,  $4  00;  lea- 
ther, $5  00. 

The  publisher  trusts  that  the  well-earned  reputation  of  this  long-established  favorite  will  be 
more  than  maintained  by  the  present  edition.  Jdesides  a  very  thorough  revision  by  the  author,  it 
has  been  most  carefully  examined  by  the  editor,  and  the  efforts  of  both  have  been  directed  to  in- 
troducing everything  which  increased  experience  in  its  use  has  suggested  as  desirable  to  render  it 
a  complete  text-book  for  those  seeking  to  obtain  or  to  renew  an  acquaintance  with  Human  Ana- 
tomy. The  amount  of  additions  which  it  has  thus  received  may  be  estimated  from  the  fact  that 
tho  present  edition  contains  over  one-fourth  more  matter  than  the  last,  rendering  a  smaller  type 
and  an  enlarged  page  requisite  to  keep  the  volume  within  a  convenient  size.  The  author  has  not 
only  thus  added  largely  to  the  work,  but  he  has  also  made  alterations  throughout,  wherever  there 
appeared  the  opportunity  of  improving  the  arrangement  or  style,  so  as  to  present  every  fact  in  its 
most  appropriate  manner,  and  to  render  the  whole  as  clear  and  intelligible  as  possible.  The  editor 
has  exercised  the  utmost  caution  to  obtain  entire  accuracy  in  the  text,  and  has  largely  increased 
the  number  of  illustrations,  of  which  there  are  about  one  hundred  and  fifty  more  in  this  edition 
than  in  the  last,  thus  bringing  distinctly  before  the  eye  of  the  student  everything  of  interest  or 
importance. 

UEATH  (CHRISTOPHER),  F.  R.  C.  S., 

•*-*•  Teacher  of  Operative  Surgery  in  University  College,  London. 

PRACTICAL   ANATOMY:    A   Manual   of  Dissections.     From   the 

Second  revised  and  improved  London  edition.  Edited,  with  additions,  by  W.  W.  KEEN, 
M.  D.,  Lecturer  on  Pathological  Anatomy  in  the  Jefferson  Medical  College,  Philadelphia. 
In  one  handsome  royal  12ino.  volume  of  578  pag'es,  with  247  illustrations.  Extra  cloth, 
$3  50 ;  leather,  $4  00.  (Lately  Published.) 


Dr.  Keen,  the  American  editor  of  this  work,  in  his 
preface,  says:  ''In  presenting  this  American  edition 
of  'Heath's  Practical  Anatomy,'  I  feel  that  I  have 
been  instrumental  in  supplying  a  want  long  felt  for 
a  real  dissector's  manual,"  and  this  assertion  of  its 
editor  we  deem  is  fully  justified,  after  an  examina- 
tion of  its  contents,  for  it  is  really  an  excellent  work. 
Indeed,  we  do  not  hesitate  to  say,  the  best  of  its  class 
with  which  we  are  acquainted  ;  resembling  Wilson 
in  terse  and  clear  description,  excelling  most  of  the 
so-called  practical  anatomical  dissectors  in  the  scope 
of  the  subject  and  practical  selected  matter.  .  .  . 
In  reading  this  work,  one  is  forcibly  impressed  with 
the  great  pains  the  author  takes  to  impress  the  sub- 
ject upon  the  mind  of  the  student.  He  is  full  of  rare 
and  pleasing  little  devices  to  aid  memory  in  main- 


taining its  hold  upon  the  slippery  slopes  of  anatomy. 
— St.  Louis  Med.  and  Surg.  Journal,  Mar.  10,  1871. 

It  appears  to  us  certain  that,  as  a  guide  in  dissec- 
ion,  and  as  a  work  containing  facts  of  anatomy  in 
brief  and  easily  understood  form,  this  manual  is 
jomplete.  This  work  contains,  also,  very  perfect 
^lustrations  of  parts  which  can  thus  be  more  easily 
inderstood  and  studied;  in  this  respect  it  compares 
avorably  with  works  of  much  greater  pretension. 
Such  manuals  of  anatomy  are  always  favorite  work« 
with  medical  students.  We  would  earnestly  recom- 
mend this  one  to  their  attention;  it  has  excellences 
which  make  it  valuable  as  a  guide  in  dissecting,  as 
well  as  in  studying  anatomy. — Buffalo  Medical  and 
Surgical  Journal,  Jan.  1871. 


BELLAMY (E.),  F.R.C.S. 

THE  STUDENT'S  GUIDE  TO  SURGICAL  ANATOMY:  A  Text- 
Book  for  Students  preparing  for  their  Pass  Examination.    With  engravings  on  wood.    In 
one  handsome  royal  12mo.  volume.     Cloth,  $2  25.     (Just  Ready.) 
We  welcome  Mr.  Bellamy's  work,  as  a  contribu-  ,      We  cannot  too  highly  recommend  it.— Student's 

tion  to  the  study  of  regional  anatomy,  of  equal  value 


to  the  student  and  the  surgeon.  It  is  written  in  a 
clear  and  concise  style,  and  its  practical  suggestions 
add  largely  to  the  interest  attacliiug  to  its  technical 
details  — Chicago  Med.  Examiner,  March  1,  1874. 

We  cordially  congratulate  Mr.  Bellamy  upon  hav- 
ing produced  it.— Med.  Times  and  Cfaz. 


Journal. 

Mr.  Bellamy  has  spared  no  pains  to  produce  a  real- 
ly reliable  student's  guide  to  surgical  anatomy— one 
which  all  candidates  for  surgical  degrees  may  con- 
sult with  advantage,  and  which  posseses  much  ori 
ijinal  matter  — Med.  Press  and  Circular. 


MACLISE  (JOSEPH). 

SURGICAL  ANATOMY.      By  JOSEPH  MAOLISE,  Surgeon.    In  one 

volume,  very  large  imperial  quarto;  with  68  large  and  splendid  plates,  drawn  in  the  best 
style  and  beautifully  colored,  containing  190  figures,  many  of  them  the  size  of  life;  together 
with  copious  explanatory  letter-press.  Strongly  and  handsomely  bound  in  extra  cloth. 

Price  $14  00. 

"      {ions  have  hitherto,  we  think,  been  given.     While 


We  know  of  no  work  on  surgical  anatomy  which 
can  compete  with  it. — Lancet. 

The  work  of  Maclise  on  surgical  anatomy  is  of  the 
highest  value.  In  some  respects  it  is  the  best  publi- 


perator  is  shown  every  vessel  and  nerve  where 
operation  is  contemplated,  the  exact  anatomist  is 
refreshed   by   those   clear  and  uistmct  disbections, 


cation  of  its  kind  we  have  seen,  and 


worthy  of  a  |  which  every  one  must  appreciate  who  has  a  particle 
The  English  medical  press  has  quite 

nt  could  scarcely  maKe  a  uetter  investment  iu«,u  i  tj&uauotou  mo  ^v/.-o  ot  praise,  in  recommending  this 
Xu *-Tte  Western  JournalofMedicineand  Surgery,    admirable  treatise. -Boston  Med.  and  Surg.  Journ. 
No  such  lithographic  illustrations  of  surgical  re-  | 


nlace  in  the  libiary  of  any  medical  man,  while  the  j  of  enthusiasm.    The 
student  could  scarcely  make  a  better  investment  than    exhausted  the  words 


LJARTSHORNE  (HENRY),  M.D., 

-LJ-  Professor  of  Hygiene,  etc  ,  in  the  Univ.  ofTenna. 

HANDBOOK  OF   ANATOMY  AND   PHYSIOLOGY.     Second  Edi- 
tion, revised.     In  one  royal  12mo.  volume,  with  numerous  illustrations.     (Preparing.) 


HENRY  C.  LEA'S  PUBLICATIONS — (Physiology). 


MARSHALL  (JOHN),  F.  R.  S.t 

J.LL  Professor  of  Surgery  in  University  College,  London,  Ac. 

OUTLINES  OF  PHYSIOLOGY,  HUMAN  AND  COMPARATIVE. 

With  Additions  by  FRANCIS  GURNEY  SMITH,  M.  D.,  Professor  of  the  Institutes  of  Medi- 
cine in  the  University  of  Pennsylvania,  Ac.  With  numerous  illustrations.  In  one  large 
and  handsome  octavo  volume,  of  1026  pages,  extra  cloth,  $6  50;  leather,  raised  bands, 

In  fact,  in  every  respect,  Mr.  Marshall  has  present- ,  tive,  with  which  we  are  acquainted.     To  speak  oJ 
ed  us  with  a  most  complete,  reliable,  and  scientific    this  work  in  the  terms  ordinarily  used  on  such  occa- 
work,  and  we  feel  that  it  is  worthy  our  warmest 
commendation. — St.  Louis  Mod.  Reporter,  Jan.  1869. 


sions  would  not  be  agreeable  to  ourselves,  and  would 
fail  to  do  justice  to  its  author.     To  write  such  a  book 


We  doubt  if  there  is  in  the  English  language  any    a^^^0^J^^%S2t  S3 
impend  of  physiology  more  useful  to  the  student  !  £™™°J£™*  °L*™^3J?J^  £$^*¥™ 
om*  JJfea.  a?id  Surg.  Journal, 


Jan.  1869. 

It  quite  fulfils,  in  our  opinion,  the  author's  design 
of  making  it  truly  educational  in  its  character — which 
is.  perhaps,  the  highest  commendation  that  can  be 
asked. — Am.  Journ.  Med.  Sciences,  Jan.  1869. 

We  may  now  congratulate  him  on  having  com- 
pleted the  latest  as  well  as  the  best  summary  of  mod- 
ern physiological  science,  both  human  and  coinpara 


kil) 


There  arefew,  ifany,  more  accomplished  anatomists 
and  physiologists  than  the  distinguished  professor  of 
.surgery  at  University  College;  and  h€  has  long  en 
joyed  the  highest  reputation  as  a  teachei  of  physiol- 
ogy, possessing  remarkable  powers  of  cleai  exposition 
and  graphic  illustration.  We  have  rarelj  the  plea- 
sure of  being  able  to  recommend  a  text-boot  so  unre- 
servedlyasthis.—  British  Med.  Journal,  Jao  25,1868. 


/CARPENTER  (WILLIAM  £.),  M.D.,  F.  R.  S., 

Examiner  in  Physiology  and  Comparative  Anatomy  in  the  University  of  London. 

PRINCIPLES  OF  HUMAN  PHYSIOLOGY;  with  their  chief  appli- 
cations to  Psychology,  Pathology,  Therapeutics,  Hygiene  and  Forensic  Medicine.  A  net* 
American  from  the  last  and  revised  London  edition.  With  nearly  three  hundred  illustrations 
Edited,  with  additions,  by  FRANCIS  GURNET  SMITH,  M.  D.,  Professor  of  the  Institutes  of 
Medicine  in  the  University  of  Pennsylvania,  Ac.  In  one  very  large  and  beautiful  octavo 
volume,  of  about  900  large  pages,  handsomely  printed;  extra  cloth,  $5  50  ;  leather,  raised 
bands,  $6  50. 

We  doubt  not  it  is  destined  to  retain  a  strong  hold 
on  public  favor,  and  remain  the  favorite  text-book  in 
our  colleges.— Virginia  Medical  Journal. 


With  Dr.  Smith,  we  confidently  believe  "that  the 
present  will  more  than  sustain  the  enviable  reputa- 
tion already  attained  by  former  editions,  of  being 
one  of  the  fullest  and  most  complete  treatises  on  the 
subject  in  the  English  language."  We  know  of  none 
from  the  pages  of  which  a  satisfactory  knowledge  of 
the  physiology  of  the  human  organism  can  be  as  well 
obtained,  none  better  adapted  for  the  use  of  such  as 
taice  up  the  study  of  physiology  in  its  reference  to 
the  institutes  and  practice  of  medicine.— Am.  Jour. 
Med.  Sciences. 


The  above  is  the  title  of  what  is  emphatically  tht 
great  work  on  physiology  ;  and  we  are  conscious  that 
it  would  be  a  useless  effort  to  attempt  to  add  any- 
thing to  the  reputation  of  this  invaluable  work,  and 
can  only  say  to  all  with  whom  our  opinion  has  any 
influence,  that  it  is  our  authority.— Atlanta  Med. 
Journal. 


DT  THE  SAME  AUTHOR. 

PRINCIPLES  OF  COMPARATIVE  PHYSIOLOGY.    New  Ameri- 

can,  from  the  Fourth  and  Revised  London  Edition.     In  one  large  and  handsome  octavo 
volume,  with  over  three  hundred  beautiful  illustrations     Pp.  752.    Extra  cloth,  $5  00. 
As  a  complete  and  condensed  treatise  on  its  extended  and  important  subject,  this  work  becomes 
a  necessity  to  students  of  natural  science,  while  the  very  low  price  at  which  it  is  offered  places  it 
within  the  reach  of  all. 


JT'IRKES  (  WILLIAM  SENHOUSE),  M.D. 

A  MANUAL  OF  PHYSIOLOGY.     Edited  by  W.  MORRANT  BAKER, 

M.D.,  F.R.C.S.      A  new  American  from  the  eighth  and  improved  London  edition.     With 
about  two  hundred  and  fifty  illustrations.     In  one  large  and  handsome  royal  12mo.  vol- 
ume.    Cloth,  $3  25;  leather,  $3  75.     (Now  Ready.) 
Kirkes'  Physiology  has  long  been  known  as  a  concise  and  exceedingly  convenient  text-book, 

presenting  within  a  narrow  compass  all  that  is  important  for  the  student.     The  rapidity  with 

which  successive  editions  have  followed  each  other  in  England  has  enabled  the  editor  to  keep  it 

thoroughly  on  a  level  with  the  changes  and  new  discoveries  made  in  the  science,  and  the  eighth 

edition,  of  which  the  present  is  a  reprint,  has  appeared  so  recently  that  it  may  be  regarded  as 

the  latest  accessible  exposition  of  the  subject. 
On   the  whole,  there  is  very  little  in   the  book 

which  either  the  student  or  practitioner  will  notfind 

of  practical  value  and  consistent  with  our  present 

knowledge  of  this  rapidly  changing  science  ;  and  we 

h.-ive  no  hesitation  in  expressing  our  opinion  that 

this  eighth  edition  is  one  of  the  best  handbooks  on 

physiology  which  we  have  in  our  language. — N.  T. 

Med.  Record,  April  15,  1873. 


This  volume  might  well  be  used  to  replace  many 
of  the  physiological  text-books  in  use  in  this  coun- 
try. It  represents  more  accurately  than  the  works 
of  Dalton  or  Flint,  the  present  state  of  our  knowl- 
edge of  most  physiological  questions,  while  it  is 
much  less  bulky  and  far  more  readable  than  the  lar- 


ger text-books  of  Carpenter  or  Marshall.  The  book 
is  admirably  adapted  to  be  placed  in  the  hands  of 
studen;s. — Boston  Med.  and  Surg.  Journ.,  April  10, 
1873. 


In  its  enlarged  form  it  is,  in  our  opinion,  still  the 
best  book  on  physiology,  most  useful  to  the  student. 
—Phila.  Med.  Times,  Aug.  30,  1873. 

This  is  undoubtedly  the  best  work  for  students  of 
physiology  extant.— Cincinnati  Med.  Ntwn,  Sept.  '73 

It  more  nearly  represents  the  present  condition  of 
physiology  than  any  other  text-book  on  the  subject. — 
Detroit  Rev.  of  Med.  Pharm.,  Nov.  1873. 


HENRY  C.  LEA'S  PUBLICATIONS — (Physiology). 


f)ALTON  (J.  C.},  M.D., 

Professor  of  Physiology  in  the  College  of  Physicians  and  Surgeons,  New  TorTt,  &c. 

A  TREATISE  ON  HUMAN  PHYSIOLOGY.    Designed  for  the  use 

of  Students  and  Practitioners  of  Medicine.     Fifth  edition,  revised,  with  nearly  three  hui» 
dred  illustrations  on  wood.     In  one  very  beautiful  octavo  volume,  of  over  700  pages,  extra 
cloth,  $5  25  ;  leather,  $6  25.     (Lately  Isstwd.) 

Preface  to  the  Fifth  Edition. 

In  preparing  the  present  edition  of  this  work,  the  general  plan  and  arrangement  of  the  previous 
editions  have  been  retained,  so  far  as  they  have  been  found  useful  and  adapted  to  the  purposes  of 
a  text-book  for  students  of  medicine.  The  incessant  advance  of  all  the  natural  and  physical 
sciences,  never  more  active  than  within  the  last  five  years,  has  furnished  many  valuable  aide  to 
the  special  investigations  of  the  physiologist;  and  the  progress  of  physiological  research,  during 
the  same  period,  has  required  a  careful  revision  of  the  entire  work,  and  the  modification  or  re- 
arrangement of  many  of  its  parts.  At  this  day,  nothing  is  regarded  as  of  any  value  in  natural 
science  which  is  not  based  upon  direct  and  intelligible  observation  or  experiment ;  and,  accord- 
ingly, the  discussion  of  doubtful  or  theoretical  questions  has  been  avoided,  as  a  general  rule,  in 
the  present  volume,  while  new  facts,  from  whatever  source,  if  fully  established,  have  been  added 
and  incorporated  with  the  results  of  previous  investigation.  A  number  of  new  illustrations  have 
been  introduced,  and  a  few  of  the  older  ones,  which  seemed  to  be  no  longer  useful,  have  been 
omitted.  In  all  the  changes  :ind  additions  thus  made,  it  has  been  the  aim  of  the  writer  to  make  the 
book,  in  its  present  form,  a  faithful  exponent  of  the  actual  conditions  of  physiological  science. 

NEW  YORK,  October,  1871. 

In  this,  the  standard  text-book  on  Physiology,  all  that  is  needed  to  maintain  the  favor  with  which 
it  is  regarded  by  the  profession,  is  the  author's  assurance  that  it  has  been  thoroughly  revised  and 
brought  up  to  a  level  with  the  advanced  science  of  the  day.  To  accomplish  this  has  required 
some  enlargement  of  the  work,  but  no  advance  has  been  made  in  the  price. 


The  fifth  edition  of  this  truly  valuable  work  on 
Human  Physiology  comes  to  us  with  many  valuable 
improvements  and  additions.  As  a  text-book  of 
physiology  the  work  of  Prof.  Dalton  has  long  been 
well  known  as  one  of  the  best  which  could  be  placed 
in  the  hands  of  student  or  practitioner.  Prof.  Dalton 
has,  in  the  several  editions  of  his  work  heretofore 
published,  labored  to  keep  step  with  the  advancement 
in  science,  and  the  last  edition  shows  by  its  improve- 
ments on  former  ones  that  he  is  determined  to  main- 
tain the  high  standard  of  his  work.  We  predict  for 
the  present  edition  increased  favor,  though  this  work 
has  long  been  the  favorite  standard. — Buffalo  Med. 
and  Surg.  Journal,  April,  1872. 

An  extended  notice  of  a  work  so  generally  and  fa- 
vorably known  as  this  is  unnecessary.  It  is  justly 
regarded  as  one  of  the  most  valuable  text-books  on 
the  subject  in  the  English  language.— St.  Louie  Med. 
Archives,  May,  1872. 

We  know  no  treatise  in  physiology  so  clear,  com- 
plete, well  assimilated,  and  perfectly  digested,  as 
Dalton's.  He  never  writes  cloudily  or  dubiously,  or 
in  mere  quotation.  He  assimilates  all  his  material, 
and  from  it  constructs  a  homogeneous  transparent 
argument,  which  is  always  honest  and  well  informed, 
and  hides  neither  truth,  ignorance,  nor  doubt,  so  far 
as  either  belongs  to  the  subject  in  hand  —  Brit.  Med. 
Journal,  March  23,  1872. 


Dr.  Dalton's  treatise  is  well  known,  and  by  many 
highly  esteemed  in  this  country.  It  is,  indeed,  a  good 
elementary  treatise  on  the  subject  it  professes  to 
teach,  and  may  safely  be  put  into  the  hands  of  Eng- 
lish students.  It  has  one  great  merit — it  is  clear,  and, 
on  the  whole,  admirably  illustrated.  The  part  we 
have  always  esteemed  most  highly  is  that  relating 
to  Embryology.  The  diagrams  given  of  the  various 
stages  of  development  give  a  clearer  view  of  the  sub- 
ject than  do  those  in  general  use  in  this  country  ;  and 
the  text  may  be  said  to  be,  upon  the  whole,  equally 
clear. — London  Med.  Times  and  Gazette,  March  23, 
1872. 

Dalton's  Physiology  is  already,  and  deservedly, 
the  favorite  text-book  of  the  majority  of  Americaa 
medical  students.  Treating  a  most  interesting  de- 
partment of  science  in  his  own  peculiarly  lively  and 
fascinating  style,  Dr.  Dalton  carries  his  reader  along 
without  effort,  and  at  the  same  time  impresses  upon 
his  mind  the  truths  taught  much  more  successfully 
thau  if  they  were  buried  beneath  a  multitude  of 
words. — Kansas  City  Med.  Journal,  April,  1872. 

Professor  Dalton  is  regarded  j  ustly  as  the  authority 
in  this  country  on  physiological  subjects,  and  the 
fifth  edition  of  his  valuable  work  fully  justifies  th« 
exalted  opinion  the  medical  world  has  of  his  labors. 
This  last  edition  is  greatly  ealarged. — Virginia  Clin- 
ical Record,  April,  1872. 


TkUNGLISON  (ROBLEY],  M.D., 

J-J  Professor  of  Institutes  of  Medicine  in  Jefferson  Medical  CoUeye,  Philadelphia. 

HUMAN  PHYSIOLOGY.     Eighth  edition.    Thoroughly  revised  and 

extensively  modified  and  enlarged,  with  five  hundred  and  thirty-two  illustrations.     In  two 
large  and  handsomely  printed  octavo  volumes  of  about  1500  pages,  extra  cloth.     $7  00. 


T  EHMANN  (C.  G.). 

PHYSIOLOGICAL  CHEMISTRY.  Translated  from  the  second  edi- 
tion by  GEORGE  B.  DAY,  M.  D.,  F.  R.  S.,  Ac.,  edited  by  R.  E.  ROGERS,  M.  D.,  Professor  of 
Chemistry  in  the  Medical  Department  of  the  University  of  Pennsylvania,  with  illustration* 
selected  from  Funke's  Atlas  of  Physiological  Chemistry,  and  an  Appendix  of  plates.  Com- 
plete in  two  large  and  handsome  octavo  volumes,  containing  1200  pages,  with  nearly  two 
hundred  illustrations,  extra  cloth.  $6  00. 


T)T  THE  SAME  AUTHOR. 

MANUAL  OF  CHEMICAL  PHYSIOLOGY.    Translated  from  the 

German,  with  Notes  and  Additions,  by  J  CHESTON  MORRFS,  M.  D.,  with  an  Introductory 
Essay  on  Vital  Force,  by  Professor  SAMUEL  JACKSON,  M.  D.,  of  the  University  of  Pennsyl- 
vania. With  illustrations  on  wood.  In  one  very  handsome  octavo  volume  of  336  pages, 
estra  elotfe.  $225. 


10 


HENRY  C.  LEA'S  PUBLICATIONS — (Chemistry}. 


[TTFIELD  (JOHN],  Ph.D., 

Professor  of  Practical  Chemistry  to  the,  Pharmaceutical  Society  of  Great  Britain,  Ac. 

CHEMISTRY,    GENERAL,  MEDICAL,  AND  PHARMACEUTICAL; 

including  the  Chemistry  of  the  IT.  S.  Pharmacopoeia.  A  Manual  of  the  General  Principles 
of  the  Science,  and  their  Application  to  Medicine  and  Pharmacy.  Fifth  Edition,  revised 
by  the  author.  In  one  handsome  royal  12mo.  volume  ;  cloth,  $2  75  ;  leather,  $3  25. 
(Jitst  Issued.) 


We  commend  the  work  heartily  as  one  of  the  best 
text-books  extant  for  the  medical  student. — Detroit 
Rev.  of  Med.  and  Pharm.,  Feb.  1872. 

The  best  work  of  the  kind  in  the  English  language. 
— N.  Y.  Psychological  Journal,  Jan.  1872. 

The  work  is  constructed  with  direct  reference  to 
the  wants  of  medical  and  pharmaceutical  students; 
and,  although  an  English  work,  the  points  of  differ- 
ence between  the  British  and  United  States  Pharma- 
copoeias are  indicated,  making  it  as  useful  here  as  in 
England.  Altogether,  the  book  is  one  we  can  heart- 
ily recommend  to  practitioners  as  well  as  students. 
— N.  T.  Med.  Journal,  Dec.  1871. 

It  differs  from  other  text-books  in  the  following 
particulars  :  first,  in  the  exclusion  of  matter  relating 
to  compounds  which,  at  present,  are  only  of  interest 
to  the  scientific  chemist ;  secondly,  in  containing  the 
chemistry  of  every  substance  recognized  officially  or 
in  general,  as  a  remedial  agent.  It  will  be  found  a 
most  valuable  book  for  pupils,  assistants,  and  others 
engaged  in  medicine  and  pharmacy,  and  we  heartily 
commend  it  to  our  readers. — Canada  Lancet,  Oct. 
1871. 

When  the  original  English  edition  of  this  work  was 


published,  we  had  occasion  to  express  our  high  ap- 
preciation of  its  worth,  and  also  to  review,  in  con- 
siderable detail,  the  main  features  of  the  book.  As 
the  arrangement  of  subjects,  and  the  main  part  of 
the  text  of  the  present  edition  are  similar  to  the  for- 
mer publication,  it  will  be  needless  for  us  to  go  over 
the  ground  a  second  time ;  we  may.  however,  call  at- 
tention to  a  marked  ad  vantage  possessed  by  the  Ame- 
rican work— we  allude  to  the  introduction  of  the 
chemistry  of  t.he  preparations  of  the  United  States 
Pharmacopoeia,  as  well  as  that  relating  to  the  British 
authority.  —  Canadian  Pharmaceutical  Journal, 
Nov.  1871. 

Chemistry  has  borne  the  name  of  being  a  hard  sub- 
ject to  master  by  the  student  of  medicine,  and 
chiefly  because  so  much  of  it  consists  of  compounds 
only  of  interest  to  the  scientific  chemist ;  in  this  work 
such  portions  are  modified  or  altogether  left  out,  and 
in  the  arrangement  of  the  subject  matter  of  the  work, 
practical  utility  is  sought  after,  and  we  think  fully 
attained  We  commend  it  for  its  clearness  and  order 
to  both  teacher  and  pupil. — Oregon  Med,.  and  Surg. 
Reporter,  Oct.  1871. 


-DLOXAM  (C.  L.}, 

-LJ  Professor  of  Chemistry  in  King's  College,  London. 

CHEMISTRY,  INORGANIC  AND  ORGANIC.  From  the  Second  Lon- 
don Edition.  In  one  very  handsome  octavo  volume,  of  700  pages,  with  about  300  illustra- 
tions. Cloth,  $4  50;  leather,  $5  50.  (Now  Heady.) 

It  has  been  the  author's  endeavor  to  produce  a  Treatise  on  Chemistry  sufficiently  comprehen- 
sive for  those  studying  the  science  as  a  branch  of  general  education,  and  one  which  a  student 
may  use  with  advantage  in  pursuing  his  chemical  studies  at  one  of  the  colleges  or  medical  schools. 
The  special  attention  devoted  to  Metallurgy  and  some  other  branches  of  Applied  Chemistry  renders 
the  work  especially  useful  to  those  who  are  being  educated  for  employment  in  manufacture. 


It  would  be  difficult  for  a  practical  chemist  and 
teacher  to  find  any  material  fault  with  this  most  ad- 
mirable treatise.  The  author  has  given  us  almost  a 
cyclopedia  within  the  limits  of  acunvenient  volume, 
and  has  done  so  without  penning  the  useless  para- 
graphs too  commonly  making  up  a  great  part  of  the 
bulk  of  many  cumbrous  works.  The  progressive  sci- 
entist is  not  disappointed  when  he  looks  for  the  record 
of  new  and  valuable  processes  and  discoveries,  while 
the  cautious  conservative  does  not  find  its  pages  mo- 
ropolized  by  uncertain  theories  and  speculations.  A 
peculiar  point  of  excellence  is  the  crystallized  form  of 
expression  in  which  great  truths  are  expressed  in 


very  short  paragraphs.  One  is  surprised  at  the  brief 
space  allotted  to  an  important  topic,  and  yet,  after 
reading  it,  he  feels  that  little,  if  any  more,  should 
have  been  said.  Altogether,  it  is  seldom  you  see  a 
text-book  so  nearly  faultless.—  Cincinnati  Lancet, 
Nov.  1873. 

Prjfessor  Bloxam  has  given  us  a  most  excellent 
and  useful  practical  treitise.  His  666  pages  are 
crowded  with  facts  and  experiments,  nearly  all  well 
chosen,  and  many  quite  new,  even  to  scientific  m«n. 
.  .  .  It  is  astonishinghow  much  information  he  often 
conveys  in  a  few  paragraphs.  We  might  quote  fifty 
instances  of  this.— Chemical  News. 


0 


DLINO  ( WILLIAM], 

Lecturer  on  Chemistry  at  St.  Bartholomew'1 s  Hospital,  &c. 

A  COURSE  OF  PRACTICAL  CHEMISTRY,  arranged  for  the  Use 

of  Medical  Students.    With  Illustrations.    From  the  Fourth  and  Revised  London  Edition. 
In  one  neat  royal  12mo.  volume,  extra  cloth.     $2.     (Lately  Jssued.) 


S1ALLOWAY  (ROBERT),  F.C.S., 

Prof,  of  Applied  Chemistry  in  the  Royal  College  of  Science  for  Ireland,  Ac. 

A  MANUAL  OF  QUALITATIVE  ANALYSIS.  From  the  Fifth  Lon- 
don Edition.  In  one  neat  royal  12mo.  volume,  with  illustrations  ;  extra  cloth,  $2  50.  (Just 
Issued. ) 

The  success  which  has  carried  this  work  through  repeated  editions  in  England,  and  its  adoption 
as  a  text-book  in  several  of  the  leading  institutions  in  this  country,  show  that  the  author  has  suc- 
ceeded in  the  endeavor  to  prodmce  a  sound  practical  manual  and  book  of  reference  for  the  che- 
mical student. 

Prof  Galloway's  books  are  deservedly  in  nigh  >  We  regard  this  volume  as  a  valuable  addition  to 
esteem,  and  this  American  reprint  of  the  fifth  edition  !  the  chemical  text-books,  and  as  particularly  calcn- 
(1869)  of  his  Manual  of  Qualitative  Analysis,  will  be  lated  to  instruct  the  student  in  analytical  researches 
acceptable  to  many  American  students  to  whom  the  of  the  inorganic  compounds,  the  important  vegetable 
English  edition  is  not  accessible. — Am.  Jour,  of  Sci-  acid*,  and  of  compounds  and  various  >-eeretiou*  and 
«nce  and  Arts,  Sept.  1872.  excretions  of  animal  origin. — Am.  Journ.  of  Pliarrn., 

Sept.  1S72. 


_  _  HENRY  C.  LEA'S  PUBLICATIONS—  (  Chemistry)..  1  1 

/^HANDLER  (CHARLES  P.),      and     CHANDLER  (WILLIAM  H.), 

Prof,  of  Chemistry  in  the  N.  Y.  Coll.  of  U  Prof  nf  Chemistry  in  the  Lehigh 

Pharmacy.  University. 

THE    AMERICAN    CHEMIST:    A  Monthly  Journal  of  Theoretical, 

Analytical,  and  Technical  Chemistry.     Each  number  averaging  forty  large  double  col- 
umned pages  of  reading  matter.    Price  $5  per  annum  in  advance.    Single  numbers,  50  cts. 


Specimen  numbers  to  parties  proposing  to  subscribe  will  be  sent  to  any  address  on  receipt 
of  25  cents. 

*%*  Subscriptions  can  begin  with  any  number. 

The  rapid  growth  of  the  Science  of  Chemistry  and  its  infinite  applications  to  other  sciences 
and  arts  render  a  journal  specially  devoted  to  the  subject  a  necessity  to  those  whose  pursuits 
require  familiarity  with  the  details  of  the  science.  It  has  been  the  aim  of  the  conductors  of  "THE 
AMERICAN  CHEMIST"  to  supply  this  want  in  its  broadest  sense,  and  the  reputation  which  the 
periodical  has  already  attained  is  a  sufficient  evidence  of  the  zeal  and  ability  with  which  they 
have  discharged  their  task. 

Assisted  by  an  able  body  of  collaborators,  their  aim  is  to  present,  within  a  moderate  compass, 
an  abstract  of  the  progress  of  the  science  in  all  its  departments,  scientific  and  technical.  Import- 
ant original  communications  and  selected  papers  are  given  in  full,  and  the  standing  of  the  "  CHEM- 
IST" is  such  as  to  secure  the  contributions  of  leading  in*-  in  all  portions  of  the  country.  Besides 
this?,  over  one  hundred  journals  and  transactions  oF  learned  societies  in  America,  Great  Britain, 
France,  Belgium,  Italy,  Russia,  and  Germany  are  carefully  scrutinized,  and  whatever  they  offer 
of  interest  is  condensed  and  presented  to  the  reader.  In  this  work,  which  forms  a  special  feature 
of  the  "CHEMIST,"  the  editors  have  the  assistance  of  M.  Alsberg,  Ph.D.,  Prof.  G.  P.  .Barker,  T. 
M.  Blossom,  E.M.,  H.  C.  Bolton,  Ph.D.,  Prof.  T.  Egleston,  E.M  ,  H.  Endemann,  Ph.D.,  Prof.  C. 
A.  Goessmann,  Ph.D.,S.  A.  Goldschmidt,  A.M.,  E.M.,  E.  J.  Hallock,  Prof.  C.  A.  Joy,  Ph  D. 
J.  P.  Kimball,  Ph.D.,  0.  G.  Mason,  H.  Newton,  E.M.,  Prof.  Frederick  Prime,  Jr.,  Prof.  Paul 
Schweitzer,  Ph.D.,  Waldron  Shapleigh,  Romyn  Hitchcock,  and  Elwyn  Waller,  E.M.  From  the 
thoroughness  and  completeness  with  which  this  department  is  conducted,  it  is  believed  that  no 
periodical  in  either  hemisphere  more  faithfully  reflects  the  progress  of  the  science,  or  presents  a 
larger  or  more  carefully  garnered  store  of  information  to  its  readers. 

jpOWNES  (GEORGE),  Ph.D. 
.       A  MANUAL  OF  ELEMENTARY  CHEMISTRY;   Theoretical  and 

Practical.    With  one  hundred  and  ninety-seven  illustrations.    A  new  American,  from  the 

tenth  and  revised  London  edition.     Edited  by  ROBERT  BRIDGES,  M.  D.     In  one  large 

royal  12mo.  volume,  of  about  850  pp.,  extra  cloth,  $2  75  ;  leather,  $3  25.    (Lately  Issued.) 

This  work  is  so  well  known  that  it  seems  almost    Uher  work  that  has  greater  claims  oa  the  physician, 

superfluous  for  us  to  speak  about  it.     It  has  been  a    pharmaceutist,  or  student,  than  this.     We  cheerfully 

favorite  text-book  with  medical  students  for  years,    recommend  it  as  the  hest  text-book  on  elementary 

and   its  popularity   has  in   no  respect  diminished,    chemistry,  and  bespeak  for  it  the  careful  attention 

Whenever  we  have  been  consulted  by  medical  stu-    of  students  of  pharmacy.—  Chicago  Pharmacist,  Aug. 

dents,  as  has  frequently  occurred,  what  treatise  on  •  1869. 

chemistry  they  should  procure,  we  have  always  re-! 

commended  Fownes',  for  we  regarded  it  as  the  best.  !  Here  is  a  new  edition  which  has  been  long  watched 
There  is  no  work  that  combines  so  many  excellen-  >  for  bv  eager  teachers  of  chemistry.  In  its  new  garb, 
ces.  It  is  of  convenient  size,  not  prolix,  of  plain  aad  aider  the  editorship  of  Mr.  Watts,  it  ha«  resumed 
perspicuous  diction,  contains  all  the  most  recent  its  old  Place  as  tae  most  successful  of  text-books.— 
discoveries,  and  is  of  moderate  price.—  Cincinnati  /»<#«»  Medical  Gazette,  Jan.  1,  1869 


.  Repertory,  Aug.  1869. 


u  wiu  continaet  as  heretofore,  to  hold  the  first  rank 


, 

Large  additions  have  been  made,  especially  in  the  i  is   a  text-book  for  students  of  medicine.—  Chicago 
department  of  organic  chemistry,  and  we  know  of  no     Wed.  Examiner,  Aug.  1869. 


\\TOHLER  AND  FIT  TIG. 

OUTLINES  OF  ORGANIC  CHEMISTRY.     Translated  with  Ad- 

ditions  from  the  Eighth  German  Edition.  By  IRA  REMSEN,  M.D.,  Ph.D.,  Professor  of 
Chemistry  and  Physics  in  Williams  College,  Mass.  In  one  handsome  volume,  royal  12mo. 
of  550  pp.  extra  cloth,  $3.  (Just  Issued.) 

As  the  numerous  editions  of  the  original  attest,  this  work  is  the  leading  text-book  and  standard 
authority  throughout  Germany  on  its  important  and  intricate  subject — a  position  won  for  it  by 
the  clearness  and  conciseness  which  are  its  distinguishing  characteristics.  The  translation  has 
been  executed  with  the  approbation  of  Profs.  Wbhler  and  Fittig,  and  numerous  additions  and 
alterations  have  been  introduced,  so  as  to  render  it  in  every  respect  on  a  level  with  the  most 
advanced  condition  of  the  science. 

DOWMAN  (JOHN  E.),M.  D. 
PRACTICAL  HANDBOOK  OF  MEDICAL  CHEMISTRY.    Edited 

by  C.   L.   BLOXAM,  Professor  of  Practical  Chemistry  in  King's  College,  London.      Sixth 
American,  from  the  fourth  and  revised  English  Edition.     In  one  neat  volume,  royal  12mo., 
pp.  351,  with  numerous  illustrations,  extra  cloth.     $2  25. 
OF  THE  SAME  AUTHOR.     (Now  Run'y  ) 

INTRODUCTION   TO   PRACTICAL  CHEMISTRY,  INCLUDING 

ANALYSIS.  Sixth  American,  from  the  sixth  and  revised  London  edition.  With  numer- 
ous illustrations.  In  one  neat  vol.,  royal  12mo.,  extra  cloth.  $2  25. 

KNAPP'S  TECHNOLOGY  ;  or  Chemistry  Applied  to  I      very  handsome  octavo   volumes,  with  500   wood 
<-.h«    \rts,  and   to  Manufactures.    With  American        engravings,  extra  cloth,  $6  00 
additi  >Q8,  by  Prof.  WAI/FEB  K.  JOHNSON.    In  two  I 


12       HENRY  C.  LEA'S  PUBLICATIONS — (Mat.Med.and  Therapeutics). 


PARRISH  (EDWARD], 

Late  Professor  of  Materia  Medica  in  the  Philadelphia  College  of  Pharmacy. 

A  TREATISE  ON  PHARMACY.     Designed  as  a  Text-Book  for  the 

Student,  and  as  a  Guide  for  the  Physician  and  Pharmaceutist.  With  many  Formulae  and 
Prescriptions.  Fourth  Edition,  thoroughly  revised,  by  THOMAS  S.  WIEGAND.  In  one 
handsome  octavo  volume  of  977  pages,  with  280  illustrations;  cloth,  $5  50  ;  leather,  $6  50. 
(J\row  Ready.) 

The  delay  in  the  appearance  of  the  new  U.  S.  Pharmacopoeia,  and  the  sudden  death  of  the  au- 
thor, have  postponed  the  preparation  of  this  new  edition  beyond  the  period  expected.  The  notes 
and  memoranda  left  by  Mr.  Parrish  have  been  placed  in  the  hands  of  the  editor,  Mr.  Wiegaml, 
who  has  labored  assiduously  to  embody  in  the  work  all  the  improvements  of  pharmaceutical  sci- 
ence which  have  been  introduced  during  cbe  last  ten  years.  It  is  therefore  hoped  that  the  new 
edition  will  fully  maintain  the  reputation  which  the  volume  has  heretofore  enjoyed  as  a  standard 
text-book  and  work  of  reference  for  all  engaged  in  the  preparation  and  dispensing  of  medicines. 
We  have  examined  this  large  volume  with  a  good  ,  not  wish  it  to  be  understood  as  very  extravaganv. 
deal  of  care,  and  find  that  the  author  has  completely 
exhausted  the  subject  upon  which  he  treats  ;  a  more 
complete  work,  we  think,  it  would  be  impossible  to 
find.  To  the  student  of  pharmacy  the  work  is  indis- 
pensable ;  indeed,  so  far  as  we  know,  it  is  the  only  one 
of  its  kind  in  existence,  and  even  to  the  physician  or 
medical  student  who  can  spare  five  dollars  to  pur- 
chase it,  we,  feel  sure  the  practical  information  he 
will  obtain  will  more  than  compensate  him  for  the 


outlay.— Canada  Med.  Journal,  Nov.  1864. 

The  medical  student  and  the  practising  physician 
will  find  the  volume  of  inestimable  worth  for  study 
and  reference.— San  Francisco  Med.  Press,  July, 
1864. 

When  we  say  that  tbis  book  is  in  some  respects 
the  best  which  has  been  published  on  the  subject  in  . 
the  English  language  for  a  great  many  years,  we  do  I 


praise.     In  truth,  it  is  not  so  much  the  best  as  th« 
only  book. — The  London  Chemical  News. 

An  attempt  to  furnish  anything  like  an  analysis  o1 
Parrisb's  very  valuable  and  elaborate  Treatise  on 
Practical  Pharmacy  would  require  more  space  than 
we  have  at  our  disposal.  This,  however,  is  not  so 
much  a  matter  of  regret,  inasmuch  as  it  would  be 
difficult  to  think  of  any  point,  however  minute  and 


apparently  trivial,  connected  with  the  manipulation 
>f  pharmaceutic  substances  or  appliances  which  has 
not  been  clearly  and  carefully  discussed  in  this  vol- 
ume. Want  of  space  prevents  our  enlarging  farther 
on  this  valuable  work,  and  we  must  conclude  by  8 
simple  expression  of  our  hearty  appreciation  of  its 
merits. — ^Dublin  Quarterly  Jour,  of  Medical  Science, 
August,  1864. 


VTILLE  (ALFRED),  M.D., 

A3  Professor  of  Theory  and  Practise  of  Medicine  in  the  University  of  Penna. 

THERAPEUTICS  AND  MATERIA  MEDICA;  a  Systematic  Treatise 

on  the  Action  and  Uses  of  Medicinal  Agents,  including  their  Description  and  History 
Fourth  edition,  revised  and  enlarged.    In  two  large  and  handsome  8vo.  vols.    (Pr<  paring*} 
Dr.  Stille's  splendid  work  on  therapeutics  and  ma- ,  abroad  us  reputation  as  a  standard  treatise  ou  Matoru. 
teria  medica.—  London  Med.  Times,  April  8,  1865. 


Dr.  Still6  stands  to-day  one  of  the  best  and  most 
honored  representatives  at  home  and  abroad,  of  Ame- 
rican medicine ;  and  these  volumes,  a  library  in  them- 


Medica is  securely  established.  It  is  second  to  no 
work  on  the  subject  in  the  English  tongue,  and,  in- 
deed, is  decidedly  superior,  in  some  respects,  to  any 
other.—  Pacific  Med.  and  Surg  Journal,  July,  186S. 


selves,  a  treasure-house  for  every  studious  physician,  !      Stille's  Therapeutics  is  incomparably  the  best  wori 
assure  his  fame  even  had  he  done  nothing  more.— The  \  on  the  subject.— .tf.  Y.  Med.  Gazette,  Sept.  26,  1868. 

Dr.  Stille's  work  is  becoming  the  best  known  of  any 
of  our  treatises  oa  Materia  Medica.  .  .  .  One  of  the 
most  valuable  works  in  the  language  on  the  subject* 
of  which  it  treats.— N.  Y.  Med.  Journal,  Oct.  1868. 


Western  Journal  of  Medicine,  Dec.  1868. 

We  regard  this  work  as  the  best  one  on  Materia 
Medica  in  the  English  language,  and  as  such  it  de- 
serves the  favor  it  has  received. — Am.  Journ.  Medi- 
cal Sciences,  July  1868. 

We  need  not  dwell  on  the  merits  of  the  third  edition 
of  this  magnificently  conceived  work.  It  is  the  work 
on  Materia  Medica,  in  which  Therapeutics  are  prima- 
rily considered — the  mere  natural  history  of  drugs 
being  briefly  disposed  of.  To  medical  practitioners 
this  is  a  very  valuable  conception.  It  is  wonderful 
how  much  of  the  riches  of  the  literature  of  Materia 
Medica  has  been  condensed  into  this  book.  The  refer- 
ences alone  would  make  it  worth  possessing.  But  it 
is  not  a  mere  compilation.  The  writer  exercises  a 
good  judgment  of  his  own  on  the  great  doctrines  and 
points  of  Therapeutics  For  purposes  of  practice, 
Stille's  book  is  almost  unique  as  a  repertory  of  in- 
formation, empirical  and  scientific,  on  the  actions  and 
nses  of  medicines. — London  Lancet,  Oct.  31,  1868. 

Through  the  former  editions,  the  professional  world 
is  well  acquainted  with  this  work.  At  home  and 


The  rapid  exhaustion  of  two  editions  of  Prof. 
scholarly  work,  and  the  consequent  necessity  for  ft 
third  edition,  is  sufficient  evidence  of  the  high  esti- 
mate placed  upon  it  by  the  profession.  It  is  no  exag- 
geration to  say  that  there  is  no  superior  work  upon 
the  subject  in  the  English  language.  The  presec} 
edition  is  fully  up  to  the  most  recent  advance  in  th« 
science  and  art  of  therapeutics. — Leavenworth  Medi- 
cal Herald,  Aug.  1 868. 

The  work  of  Prof.  Stil>6  has  rapidly  taken  a  higfe 
place  in  professional  esteem,  and  to  say  that  a  third 
edition  is  demanded  and  now  appears  before  us,  suffi- 
ciently attests  the  firm  position  this  treatise  has  made 
for  itself.  As  a  work  of  great  research,  and  scholar- 
ship, it  is  safe  to  say  we  have  nothing  superior.  It  is 
exceedingly  full,  and  the  busy  practitioner  will  find 
ample  suggestions  upon  almost  every  important  poiu* 
of  therapeutics. — Cincinnati  Lancet,  Aug.  1868. 


f>EREIRA  (JONATHAN),  M.D.,  F.R.S.  and  L.S. 

MATERIA   MEDICA   AND  THERAPEUTICS;   being  an  Abridg- 

ment  of  the  late  Dr.  Pereira's  Elements  of  Materia  Medica,  arranged  in  conformity  with 

the  British  Pharmacopoeia,  and  adapted  to  the  use  of  Medical  Practitioners,  Chemists  and 

Druggists,  Medical  and  Pharmaceutical  Students,  Ac.     By   F.   J.  FARRE,  M.F  ,  Senior 

Physician  to  St.  Bartholomew's  Hospital,  and  London  Editor  of  the  British  Pharmacopoeia, 

assisted  by  ROBERT  BENTLEY,  M.R.C.S.,  Professor  of  Materia  Medica  and  Botaay  to  the 

Pharmaceutical  Society  of  Great  Britain;  and  by  ROBERT  WARINGTOS,  F.R.S.,  Chemical 

Operator  to  the  Society  of  Apothecaries.     With  numerous  additions  and  references  to  the 

United  States  Pharmacopoeia,  by  HORATIO  C.  WOOD,  M.D.,  Professor  of  Botany  in  the 

University  of  Pennsylvania.      In  one  large  and  handsome  octavo  volume  of  1040  closely 

printed  pages,  with   236  illustrations,  extra  cloth,  $7  00;    leather,   raised  bands,  $8  00 

It  will  fill  a  place  which  no  other  work  can  occupy  I  ed  in  the  thapeofa  complete  treatise  on  materia  med- 

in  the  library  of  the  physician,  student,  and  apothe-  |  ica,  and  the  medical  student  has  a  text-book   whkk, 

c.try. — Boston  Med.  and  Surg.  Journal,  Nov.  8,  1866.  |  for  practical  utility  and  intrinsic  worth,  stands  ua- 

The  American  physician  now  has  all  that  is  need:  1  P»r*ll*led.-tf.  Y.  M«d.  Sword,  Kov.  15, 1S66. 


C.  LEA'S  PUBLICATIONS— (Mat.  Mt>d.  and  Therapeutics).       13 
QRIFFITH  (ROBERT  E.),  M.D. 

A  UNIVERSAL  FORMULARY,  Containing  the  Methods  of  Prepar- 
ing and  Administering  Officinal  and  other  Medicines.    The  whole  adapted  to  Physician   and 
Pharmaceutists.     Third  ed  tion,  thoroughly  revised,  with  numerous  additions,  b\  JOHN  M 
MAISCH   Professor  of  Materia  Medica  in  the  Philadelphia  College  of  Pharmacy.   In  one  large 
lhandsome  octavo  volume  of  about  800  pages  :  cloth,  $4  50  ;  leather,  $5  50.   (Just  Ready) 
This  work  has  long  been  known  for  the  vast  amount  of  information  which  it  presents  in  a  con 
densed  form,  arranged  for  easy  reference.     The  new  edition  has  received  the  most  careful  reg- 
ion at  the  competent  hands  of  Professor  Maisch,  who  has  brought  the  whole  up  to  the  standard  of 
the  most  recent  authorities.     More  than  eighty  new  headings  of  remedies  have  been  introduced, 
the  entire  work  has  been  thoroughly  remodelled,  and  whatever  has  seemed  to  be  obsolete  has  been 
omitted.     As  a  comparative  view  of  the  United  States,  the  British,  the  German,  and  the  French 
Pharmacopoeias,  together  with  an  immense  amount  of  unofficial  formulas,  it  affords  to  the  prac- 
titioner and  pharmaceutist  an  aid  in  their  daily  avocations  not  to  be  found  elsewhere  while  three 
indexes,  one  of  "Diseases  and  their  Remedies,"  one  of  Pharmaceutical  Names,  and  a  General 

lex,  aftord  an  easy  key  to  the  alphabetical  arrangement  adopted  in  the  text. 

The  young  practitioner  will  find  the  work  invalu-    Directions,  Poisons.  Antidotes,  and  Treatment,  and 

copious  indices,  which  afford  ready  access  to  all  parts 
of  the  work.  We  unhesitatingly  commend  the  book 
as  being  the  best  of  its  kind,  within  our  knowledge. 
— Atlanta  Med.  and  Surg.  Journ.,  Feb.  1874. 

To  the  druggist  a  good  formulary  is  simply  indis- 
pensable, and  perhaps  no  formulary  has  been  more 
extensively  used  than  the  well-known  work  before 
us.  Many  physicians  have  to  officiate,  also,  as  drug- 
gists. This  is  true  especially  of  the  country  physi- 
cian, and  a  work  which  shall  teach  him  the  means 
by  which  to  administer  or  combine  his  remedies  in 
the  most  efficacious  and  pleasant  manner,  will  al- 
ways hold  its  place  upon  his  shelf.  A  formulary  of 
this  kind  is  of  benefit  also  to  the  city  physician  in 
largest  practice.— Cincinnati  Olinic,  Feb.  21,  1874. 

The  Formulary  has  already  proved  itself  accepta- 
ble to  the  medical  profession,  and  we  do  not  hesitate 
to  say  that  tbe  third  edition  is  much  improved,  and 
of  greater  practical  value,  in  consequence  of  the  care- 
ful revision  of  Prof  Maisch.— Chicago  Med.  Exam- 
iner, March  15,  1874. 


of  administering 
many  remedies.—  Am.  Journ.  of  Pharm.,  Feb.  1874. 

Oar  copy  of  Griffith's  Formulary,  after  long  use, 
first  in  the  dispensing  shop,  and  afterwards  in  our 
medical  practice,  had  gradually  fallen  behind  in  the 
onward  march  of  rnateria  medica,  pharmacy,  and 
therapeutics,  until  we  had  ceased  to  consult  it  as  a 
daily  hook  of  reference.  So  completely  has  Prof. 
Maisch  reformed,  remodelled,  and  rejuvenated  it  in 
the  new  edition,  we  shall  gladly  welcome  it  back  to 
our  table  again  beside  Duuglison,  Webster,  and  Wood 
&  Bache.  The  publisher  could  not  have  been  more 
fortunate  in  the  selection  of  an  editor.  Prof.  Maisch 
is  eminently  the  man  for  the  work,  and  he  has  done 
it  thoroughly  and  ably.  To  enumerate  the  altera- 
tions, amendments,  and  additions  would  be  an  end- 
less task  ;  everywhere  we  are  greeted  with  the  evi- 
dences of  his  labor.  Following  the  Formulary,  is  an 
addendum  of  useful  Recipes,  Dietetic  Preparations, 
List  of  locompatibles,  Posological  table,  table  of 
Pharmaceutical  Names,  Officinal  Preparations  and 


&LLIS  (BENJAMIN],  M.D. 
THE  MEDICAL  FORMULARY:  being  a  Collection  of  Prescriptions 

derived  from  the  writings  and  practice  of  many  of  the  most  eminent  physicians  of  America 
and  Europe.  Together  with  the  usual  Dietetic  Preparations  and  Antidotes  for  Poisons.  The 
whole  accompanied  with  a  few  brief  Pharmaceutic  and  Medical  Observation.  Twelfth  edi- 
tion, carefully  revised  and  much  improved  by  ALBERT  H.  SMITH,  M.D.  In  one  volume8v«. 
of  376  pages,  extra  doth,  $3  00.  (Lately  Published.) 

This  work  has  remained  for  some  time  out  of  print,  owing  to  the  anxioua  care  with  which  the 
Editor  has  sought  to  render  the  present  edition  worthy  a  continuance  of  the  very  remarkable 
favor  which  has  carried  the  volume  to  the  unusual  honor  of  a  TWELFTH  EDITION.  He  has  sedu- 
lously endeavored  to  introduce  in  it  all  new  preparations  and  combinations  deserving  of  confidence, 
besides  adding  two  new  classes,  Antemetics  and  Disinfectants,  with  brief  references  to  the  inhalation 
ef  atomised  fluids,  the  nasal  douche  of  Thudichum,  suggestions  upon  the  method  of  hypodermic 
injection,  the  administration  of  anaesthetics,  Ac.  <fec.  To  accommodate  these  numerous  additions, 
he  has  omitted  much  which  the  advance  of  science  has  rendered  obsolete  or  of  minor  importance, 
notwithstanding  which  the  volume  has  been  increased  by  more  than  thirty  pages.  A  new  feature 
will  be  found  in  a  copious  Index  of  Diseases  and  their  remedies,  which  cannot  but  increase  the 
value  of  the  work  as  a  suggestive  book  of  reference  for  the  working  practitioner.  Every  precaution 
has  been  taken  to  secure  the  typographical  accuracy  so  necessary  in  a  work  of  this  nature,  and  it 
in  hoped  that  the  new  edition  will  fully  maintain  the  position  which  "  ELLIS'  FORMULARY"  has 
long  occupied.  

S1ARSON  (JOSEPH},  M.D., 

\J  Professor  of  Materia  Mfdiea  and  Pharmacy  in  the  UnivMrstty  of  Pennsylvania,  *<?. 

SYNOPSIS  OF  THE   COURSE   OF   LECTURES   ON  MATERIA 

MEDICA  AND  PHARMACY,  delivered  in  the  University  of  Pennsylvania.  With  three 
Lectures  on  the  Modue  Operandi  of  Medicines.  Fourth  an  d  revised  edition,  extra  cloth  $3 


nrTBFGLISOJTS  NEW  REMEDIES,  WITH  FORMULAE 
FOR  THEIR  PREPARATION  AND  ADMINISTRA- 
TION Seveath  edition,  with  extensive  additions. 
One  vol.  Svo.,  pp.  770;  extra  cloth.  $1  00. 

ROYLE'S  MATERIA  MEDICA  AND  THERAPEU- 
TICS. Edited  by  JOSEPH  CARSON,  M.  D.  With 
aia«ty-eight  illustrations.  1  vol.  8vo.,  pp.  700,  ex- 
tra cloth.  $3  00. 

CHRISTISON'S  DISPENSATORY.  With  copious  ad- 
dltioae,  aad  213  large  wood-angra, viagfi.  By  B. 


EaLBSPBLD  GRIFFITH,  M.  D.  One  vol.  8vo.,  pp.  1000 ; 
extra  cloth.  $4  00. 

CARPENTER'S  PRIZE  ESSAY  ON  THE  USE  OP 
ALCOHOLIC  LIQUORS  IN  HEALTH  AND  DISEASE.  New 
edition,  with  a  Preface  by  D.  F.  COMDIE,  M.D.,  and 
explanations  of  scientific  words.  In  one  neat  12mo. 
volume,  pp.  176,  extra  cloth.  60  cents. 

DB  JONGH  ON  THE  THREE  KINDS  OF  COD-LIVEB 
OIL,  with  their  Chemical  and  Therapeutic  Pro- 
perties 1  vol.  12mo.,  cloth.  75  cents. 


H 


HENRY  C.  LEA'S  PUBLICATIONS — (Pathology,  &c.}. 


T^ENWJCK  (SAMUEL],  M.D., 

Assistant  Physician  to  th$  London  Hospital. 

THE  STUDENT'S  GUIDE  TO  MEDICAL  DIAGNOSIS.     From  the 

Third  Revised  and  Enlarged  English  Editior       With   eighty-four  illustrations  on  wood. 
In  one  very  handsome  volume,  royal  12mo.,  cloth,  $2  25.      (Now  Ready.) 

The  very  great  success  which  this  work  hns  obtained  in  England,  shows  that  it  has  supplied  an 
admitted  want  among  elementary  books  for  the  guidance  of  students  and  junior  practitioners. 
Taking  up  in  order  each  portion  of  the  body  or  class  of  disease,  the  author  has  endeavored  to 
present  in  simple  language  the  value  of  symptoms,  so  as  to  lead  the  student  to  a  correct  appreci- 
ation of  the  pathological  changes  indicated  by  them.  The  latest  investigations  have  been  care- 
fully introduced  into  the  present  edition,  so  that  it  may  fairly  be  considered  as  on  a  level  with 
the  most  advanced  condition  of  medical  science.  The  arrangement  adopted  may  be  seen  from  the 
subjoined 

aoisriDiETxrsiEiD   STJI^EI^^^R-Y-  OF  COTXTTETXTTS. 

CHAPTER  I.  Introductory.  II.  Diseases  of  the  Heart  and  Pericardium.  III.  Diseases  of  the 
Lungs.  IV.  Diseases  of  the  Throat  and  Larynx.  V.  Diseases  of  the  Kidneys.  VI.  Diseases  of 
the  Liver.  VII.  Diseases  of  the  Stomach.  VIII.  Diseases  of  the  Peritoneum  and  Intestines. 
IX.  Abdominal  Tumors.  X.  Diseases  of  the  Brain.  XI.  Fevers.  XII.  Rheumatism  and  Gout. 
XIII.  Diseases  of  the  Skin. 


G 


RE  EN  (T.  HENRY],  M.D., 

Lecturer  on  Pathology  and  Morbid  Anatomy  at  Charing -Cross  Hospital  Medical  School. 

PATHOLOGY  AND  MORBID  ANATOMY.  With  numerous  Illus- 
trations on  Wood.  In  one  very  handsome  octavo  volume  of  over  250  pages,  extra  cloth, 
$2  50.  (Lately  Published.) 

erymuch  pleased  by  onr  perusal  of  !  thology  and  morbid  anatomy.  The  author  shows  that 

he  has  been  not  only  a  student  of  the  teachings  of  his 
confreres  in  this  branch  of  science,  but  a  practical 
and  conscientious  laborer  in  the  post-mortem  cham- 
ber. The  work  will  prove  a  useful  one  to  the  great 
mass  of  students  and  practitioners  whose  time  for  de- 
votiou  to  this  class  of  studies  is  limited.— Am.  Journ. 
of  fiyi/hilography,  April,  1872. 


We  have  been 

this  little  volume.  It  is  the  only  one  of  the  kind  with 
which  we  are  acquainted,  and  practitioners  as  well 
as  students  will  find  it  a  very  useful  guide ;  for  the 
information  is  up  to  the  day,  well  and  compactly  ar- 
ranged, without  being  at  all  scanty.— London  Lan 
cet,  Oct.  7,  1871. 

It  embodies  in  a  comparatively  small  space  a  clear 
statement  of  the  present  state  of  our  knowledge  of  pa- 


GLUGE'S  ATLAS  OF  PATHOLOGICAL  HISTOLOGY 
Translated,  with  Notes  and  Additions,  by  JOSEPH 
LEIDY,  M.  D.  In  one  volume,  very  large  imperial 
quarto,  with  320  copper-plate  figures,  plain  and 
colored,  extra  cloth.  $4  00. 

LA  ROCHE  ON  YELLOW  FEVER,  considered  in  its 
Historical,  Pathological,  Etiological,  and  Therapeu- 
tical Relations.  In  two  large  and  handsome  octav< 
volumes  of  nearly  1500  pages,  extra  cloth.  $7  00 

HOLLAND'S  MEDICAL  NOTES  AND  REFLEC- 
TIONS. 1  vol.  8vo.,  pp.  500,  extra  cloth.  $3  50 

WHAT  TO  OBSERVE  AT  THE  BEDSIDE  AND  AFTE1 
DEATH  IN  MEDICAL  CASES.  Published  under  thi 
authority  of  the  London  Society  for  Medical  Obser 


vation.  From  the  second  London  edition.  1  vo 
royal  12mo.,  extra  cloth.  $1  00. 

LAYCOCK'S  LECTURES  ON  THE  PRINCIPLES 
AND  METHODS  OF  MEDICAL  OBSERVATION  AND  RE- 
SEARCH. For  the  use  of  advanced  students  and 
junior  practitioners.  In  one  very  neat  royal  12m" 
volume,  extra  cloth.  $1  00 

BARLOW'S  MANUAL  OF  THE  PRACTICE  OF 
MEDICINE.  With  Additions  by  D.  F.  CONDIE, 
*  O  1  vol  Rvo.,  pp  600.  cloth  •*?  50 

TODD'S CLINICAL  LECTURES  ON  CERTAIN  ACUTE 
DISEASES.  In  one  neat  octavo  volume,  of  320  pages, 
extra  cloth.  $2  50. 


G 


ROSS  (SAMUEL  D.\  M.  D., 

Professor  of  Surgery  in  the  Jefferson  Medical  College  of  Philadelphia. 

ELEMENTS    OF    PATHOLOGICAL   ANATOMY.     Third    edition, 

thoroughly  revised  and  greatly  improved.  In  one  large  and  very  handsome  octavo  volume 
of  nearly  800  pages,  with  about  three  hundred  and  fifty  beautiful  illustrations,  of  which  a 
large  number  are  from  original  drawings  ;  extra  cloth.  $4  00. 

TONES  (C.  HANDFIELD],F.R.S,and  SIEVEKING  (ED.  H.],  M.D., 

^  Assistant  Physicians  and  Lecturers  in  St.  Mary's  Hospital 

A  MANUAL  OF   PATHOLOGICAL  ANATOMY.     First  American 

edition,  revised.  With  three  hundred  and  ninety-seven  handsome  wood  engravings.  In 
one  large  and  beautifully  printed  octavo  volume  of  nearly  750  pages,  extra  cloth,  $3  50. 

VT  URGES  (OCTA  VH7S),  M.D.  Cantab. 

^J  Fellow  oft^e  Royal  College  of  Physicians,  &c.  <frc. 

AN   INTRODUCTION   TO    THE    STUDY    OF    CLINICAL    MED- 

ICINE.     Being  a  Guide  to  the  Investigation  of  Disease,  for  the  Use  of  Students.     In  one 

handsome  12mo.  volume,  extra  cloth,  *1  25.      (Now  Heady.) 

TABLE  OP  CONTENTS.  I.  The  Sort  of  Help  needed  by  the  Student  at  the  Bedside.  II.  Some 
General  Rules  with  Reference  to  the  Examination  of  Patients.  III.  The  Family  and  Personal 
History  of  the  Patient.  IV.  Examination  of  the  Functions.  V.  Examination  of  the  Phenomena 
connected  with  the  Brain  and  Cord  VI.  The  Physical  Examination  of  the  Chest,  its  Inspection 
and  Palpation.  VII.  Percussion  Applied  to  the  Heart  and  Lungs.  VIIU.  Auscultation  of  the 
Chest.  IX.  Examination  of  the  Abdomen  and  of  the  Secretions.  X.  The  Diagnosis.  XI.  The 
Treatment. 


HENRY  C  LEA'S  PUBLICATIONS — (Practice  of  Medicine}. 


i  ft 


(AUSTIN),  M.D., 

•*•  Professor  of  the  Principles  and  Practice  of  Medicine  in  Bellevue  Med.  College,  N.  Y. 

A   TREATISE    ON    THE    PRINCIPLES    AXD    PRACTICE    OF 

MEDICINE  ;  designed  for  the  use  of  Students  and  Practitioners  of  Medicine.  Fourth 
edition,  revised  and  enlarged.  In  one  large  and  closely  printed  octavo  volume  of  ahout  1 1 00 
pages ;  handsome  extra  cloth,  $6  00;  or  strongly  bound  in  leather,  with  raised  bands,  $7  00. 
(Just  Issued.) 

By  common  consent  of  the  English  and  American  medical  press,  this  work  has  been  assigned 
to  the  highest  position  as  a  complete  and  compendious  text-book  on  the  most  advanced  condition 
of  medical  science.  At  the  very  moderate  price  at  which  it  is  offered  it  will  be  found  one  of  the 
cheapest  volumes  now  before  the  profession. 


Admirable  arid  uuequalled.  —  Western  Journal  of 
Medicine,  Nov.  1869. 

Dr.  Flint's  work,  though  claiming  no  higher  title 
than  that  of  a  text-book,  is  really  more.  He  is  a  man 
of  large  clinical  experience,  and  his  book  is  full  of 
•uch  masterly  descriptions  of  disease  as  can  only  be 
drawn  by  a  man  intimately  acquainted  with  their 
various  forms.  It  is  not  so  long  since  we  had  the 
pleasure  of  reviewing  his  first  edition,  and  we  recog- 
nize a  great  improvement,  especially  in  the  general 
part  of  the  work.  It  is  a  work  which  we  can  cordially 
recommend  to  our  readers  as  fully  abreast  of  the  sci- 
ence of  the  day. — Edinburgh  Med.  Journal,  Oct.  '69. 

One  of  the  best  works  of  the  kind  for  the  practi- 
tiouer,  and  the  most  convenient  of  all  for  the  student. 
— Am.  Journ.  Med.  Sciences,  Jan.  1869. 

This  work,  which  stands  pre-eminently  as  the  ad- 
vance standard  of  medical  science  up  to  the  present 
time  in  the  practice  of  medicine,  has  for  its  author 
one  who  is  well  and  widely  known  as  one  of  the 
leading  practitioners  of  this  continent.  In  fact,  it  is 
seldom  that  any  work  is  ever  issued  from  the  press 
more  deserving  of  universal  recommendation. — Do- 
minion Med  Journal,  May,  1869. 

The  third  edition  of  this  most  excellent  book  scarce- 
ly needs  any  commendation  from  us  The  volume, 
as  it  stands  now,  is  really  a  marvel:  first  of  all,  it  is 


sxcellently  printed  and  bound — and  we  encounter 
that  luxury  of  America,  the  ready-cut  pages,  which 
the  Yankees  are  'cute  enough  to  insist  upon — nor  are 
these  by  any  means  trifles  ;  but  the  contents  of  the 
book  are  astonishing.  Not  only  is  it  wonderful  that 
•my  one  man  can  have  grasped  in  his  mind  the  whole 
?cope  of  medicine  with  that  vigor  which  Dr.  Flint 
shows,  but  the  condensed  yet  clear  way  in  which 
this  is  done  is  a  perfect  literary  triumph.  Dr.  Flint 
is  pre-eminently  one  of  the  strong  men,  whose  right 
to  do  this  kind  of  thing  is  well  admitted  ;  and  we  say 
no  more  than  the  truth  when  we  affirm  that  he  is 
7ery  nearly  the  only  living  man  that  could  do  it  with 
inch  results  as  the  volume  before  us. — The  London 
Practitioner,  March,  1869. 

This  is  in  some  respects  the  best  text-book  of  medi- 
jine  in  our  language,  and  it  is  highly  appreciated  on 
:he  other  side  of  the  Atlantic,  inasmuch  as  the  first 
sdition  -was  exhausted  in  a  few  months.  The  second 
edition  was  little  more  than  a  reprint,  but  the  present 
has,  as  the  author  says,  been  thoroughly  revised. 
Much  valuable  matter  has  been  added,  and  by  mak- 
ing the  type  smaller,  the  bulk  of  the  volume  is  not 
much  increased.  The  weak  point  in  many  American 
works  is  pathology,  but  Dr.  Flint  has  taken  peculiar 
pains  on  this  point,  greatly  to  the  value  of  the  book. 
—London  Med.  Times  and  Gazette,  Feb.  6,  1869. 


p  4  VT  (F.  W.),  M.  D.,  F.  R.  8., 

-*-  Senior  Asst.  Physician  to  and  Lecturer  on  Physiology,  at  Guy's  Hospital,  Ae. 

A  TREATISE  ON  THE  FUNCTION  OF  DIGESTION;  its  Disor- 
ders and  their  Treatment.  From  the  second  London  edition.  In  one  handsome  volume, 
small  octavo,  extra  cloth,  $2  00.  (Lately  Published.) 

The  work  before  us  is  one  which  deserves  a  wide  .  treatise,  and  sufficiently  exhaustive  for  all  practical 
•irculation.    We  know  of  no  better  guide  to  the  study  |  purposes. — L?awnworth  Med.  Herald,  July,  1869. 
of  digestion  and  its  disorders. — St.  Louis  Med.  and 
Burg.  Journal,  July  10,  1869. 

A  thoroughly  good  book,  being  a  careful  systematic 


A  very  valuable  work  on  the  subject  of  which  It 
treats.  Small,  yet  it  is  full  of  valuable  information. 
—Cincinnati  Med.  Repertory,  June.  1869. 


J) Y  THE  SAME  AUTHOR.     (Nearly  Ready.) 

A  TREATISE  ON  FOOD  AND  DIETETICS,  PHYSIOLOGI- 
CALLY AND  THERAPEUTICALL?  CONSIDERED.  In  one  handsome  octavo  volume 
of  nearly  600  pages. 

SUMMARY  OF  CONTENTS. 

Introductory  Remarks  on  the  Dynamic  Relations  of  Food— On  the  Origination  of  Food— The 
Constituent  Relations  of  Food— Alimentary  Principles,  their  Classification,  Chemical  Relations, 
Digestion,  Assimilation,  and  Physiological  Uses — Nitrogenous  Alimentary  Principles — Non-Ni- 
trogenous Alimentary  Principles— The  Carbo-Hydrates— The  Inorganic  Alimentary  Principles- 
Alimentary  Substances — Animal  Alimentary  Substances — Vegetable  Alimentary  Substances — 
Beverages— Condiments— The  Preservation  of  Food— Principles  of  Dietetics— Practical  Dietetics 
—Diet  of  Infants— Diet  for  Training— Therapeutic  Dietetics— Dietetic  Preparations  for  the  Inva- 
lid— Hospital  Dietaries.  

CHAMBERS  ( T.  K.),  M.  D., 

Consulting  Physician  to  St.  Mary's  Hospital,  London,  &c. 

THE  INDIGESTIONS;  or,  Diseases  of  the  Digestive  Organs  Functionally 

Treated.    Third  and  revised  Edition.    In  one  handsome  octavo  volume  of  333  pages,  extra 

cloth.     $3  00.     (Lately  Published.) 

From  this  purely  mate-  rial  point  of  view,  setting  I  tents  to  his  memory  would  tind  its  price  an  invest- 
aside  its  higher  claims  to  merit,  we  know  of  no  more  |  ment  of  capital  thai-  returned  him  a  most  usurious 
desirable  acquisition  to  a  physician's  libiary  than  I  rate  of  interest.— N.  Y.  Medical  Gazette,  Jan.  28, 
the  book  before  us.  He  who  should  commit  its  con-  |  1871 

ft  Y  THE  SAME  AUTHOR.    (Lately  Published.) 

RESTORATIVE  MEDICINE.  An  Harveian  Annual  Oration,  deliv- 
ered at  the  Royal  College  of  Physicians,  London,  on  June  24,  1871.  With  Two  Sequels. 
In  one  very  handsome  volume,  small  12mo.,  extra  cloth,  $1  00. 


16 


HENRY  C.  LEA'S  PUBLICATIONS — (Practice  of  Medicine}. 


LTARTSHORNE  (HENRY],  M.D., 

•*•-*-  Professor  of  Hygiene  in  the  University  of  Pennsylvania. 

ESSENTIALS  OF  THE  PRINCIPLES  AND  PRACTICE  OF  MEDI- 
CINE. A  handy-book  for  Students  and  Practitioners.  Fourth  edition,  revised  and  im- 
proved. In  one  handsome  royal  J2mo.  volume.  (Preparing.) 


This  little  epitome  of  medical  knowledge  has  al- 
ready been  noticed  by  us.  It  is  a  Tade  mecnm  of 
value,  including  in  a  short  space  most  of  what  is  es- 
sential in  the  science  and  practice  of  medicine.  The 
third  edition  is  well  up  to  the  present  day  in  the 
modern  methods  of  treatment,  and  in  the  use  of  newly 
discovered  drugs. — Boston  Med.  and  Surff.  Journal, 
Oct.  19,  1871. 

Certainly  very  few  volumes  contain  so  much  pre-  j 
cise  information  within  so  small  a  compass. — N,  T.  \ 
Med.  Journal,  Nov.  1871. 

The  diseases  are  conveniently  classified;  symptoms,  j 
causation,  diagnosis,  prognosis,  and  treatment  are  ' 
carefully  considered,  the  whole  being  marked  by  i 
briefness,  bat  clearness  of  expression.  Over  250  for-  j 


mulas  are  appended,  intended  as  examples  merely, 
not  as  guides  for  unthinking  practitio-uers.  A  com- 
plete index  facilitates  the  use  of  this  little  volume,  in 
which  all  important  remedies  lately  introduced,  such 
as  chloral  hydrate  and  carbolic  acid,  have  received 
their  full  shareof  attention. — Am.  Journ.  of  Pkarm., 
Nov.  1S71. 

It  is  an  epitome  of  the  whole  science  and  practice 
of  medicine,  and  will  be  found  most  valuable  to  the 
practitioner  for  easy  reference,  and  especially  to  the 
student  in  attendance  upon  lectures,  whose  time  ie 
too  much  occupied  with  many  studies,  to  consult  the 
larger  works.  Such  a  work  must  always  be  in  great 
demand.— Cincinnati  Ned.  Repertory,  Nov.  1871. 


^TSON  (THOMAS),  M.  D.,  s-c. 

LECTURES     ON     THE     PRINCIPLES    AND    PRACTICE    OF 

PHYSIC.  Delivered  at  King's  College,  London.  A  new  American,  from  the  Fifth  re- 
vised and  enlarged  English  edition.  Edited,  with  additions,  and  several  hundred  illus- 
trations, by  HENRY  HARTSHORNE,  M.D.,  Professor  of  Hygiene  in  the  University  of  Penn- 
sylvania. In  two  large  and  hand  some  Svo.vols.  Cloth,  $9  00;  leather,  $11  00.  (Just  Issued.) 

advantages   of  great  culture  and  a  ripe  experience 
combined   with    the    soundest   judgment    and    sin- 


At  length,  after  many  months  of  expectation,  we 
have  the  satisfaction  of  finding  ourselves  this  week  in 


possession  of  a  revised  and  enlarged  edition  of  Sir 
Thomas  Watson's  celebrated  Lectures.  It  is  a  sub- 
ject for  congratulation  and  for  thankfulness  that  Sir 
Thomas  Watson,  during  a  period  of  comparative  lei- 
sure, after  a  long,  laborious,  and  most  honorable  pro- 
fessional career,  while  retaining  full  possession  of  his 
high  mental  faculties,  should  have  employed  the  op- 
portunity to  submit  his  Lectures  to  a  more  thorough 


revision  than  was  possible  during  the  earlier  and 
busier  period  of  his  life.  Carefully  passing  in  Review 
some  of  the  most  intricate  and  important  pathological 
and  practical  questions,  the  results  of  his  clear  insight 
and  his  calm  judgment  are  now  recorded  for  the  bene- 
fit of  mankind,  in  language  which,  for  precision,  vigor, 
and  classical  elegance,  has  rarely  been  equalled,  and 
never  surpassed.  The  revision  has  evidently  been 
most  carefully  done,  and  the  results  appear  in  almost 
every  page.—  Brit.  Med.  Jowrn.,  Oct.  14,  1871. 

The  lectures  are  so  well  known  and  so  justly 
appreciated,  that  it  is  scarcely  necessary  to  do 
more  than  call  attention  to  the  special  advantages 
of  the  last  over  previous  editions.  In  the  revi- 
sion, the  author  has  displayed  all  the  charms  and 


cerity  of  purpose.  The  author's  rare  combination 
of  great  scientific  attainments  combined  with  won- 
derful forensic  eloquence  has  exerted  extraordinary 
influence  over  the  last  two  generations  of  physicians, 
His  clinical  descriptions  of  most  diseases  have  never 
been  equalled;  and  on  this  score  at  least  his  work 
will  live  long  in  the  future.  The  work  will  be 
sought  by  all  who  appreciate  a  great  book.— Awter. 
Journal  of  Syphilography,  July,  1872. 

We  are  exceedingly  gratified  at  the  reception  of 
this  new  edition  of  Watson,  pre-eminently  the  pri»ce 
of  English  authors,  on  "Practice."  We,  who  read 
the  first  edition  as  it  came  to  us  tardily  and  in  frag- 
ments through  the  "Medical  News  and  Library," 
shall  never  forget  the  great  pleasure  and  profit  'we 
derived  from  its  graphic  delineations  of  disease,  its 
vigorous  style  and  splendid  English.  Maturity  of 
years,  extensive  observation,  profound  research, 
and  yet  continuous  enthusiasm,  have  combined  to 
give  us  in  this  latest  edition  a  model  of  professional 
excellence  in  teaching  with  rare  beauty  in  the  mode 
of  communication.  But  this  drisnic  needs  no  eulo- 
giuro  of  ouxs. — Chicago  Med.  Jo&rn.,  July,  1872. 


jy UNGLISON,  FORBES,  TWEEDIE,  AND  CONOLLY. 

THE  CYCLOPAEDIA  OF   PRACTICAL  MEDICINE:   comprising 

Treatises  on  the  Nature  and  Treatment  of  Diseases,  Materia  Mediea  and  Therapeutics, 
Diseases  of  Women  and  Children,  Medical  Jurisprudence,  &c.  <fec.     In  four  large  super-royal 
octavo  volumes,  of  3254  double-columned  pages,  strongly  and  handsomely  bound  in  leather 
$15;  extra  cloth.    $11. 

*^*  This  work  contains  no  less  than  four  hundred  and  eighteen  distinct  treatises,  contributed 

sixty-eight  distinguished  physicians. 


(WILSON),  M.D., 

Holme  Prof,  of  Clinical  Med.,  University  Coll.,  London. 

THE  DISEASES  OF  THE  STOMACH:  Being  the  Third  Edition  of 

the  "Diagnosis  and  Treatment  of  the  Varieties  of  Dyspepsia."     Revised  and  Enlarged. 
With  illustrations.     In  one  handsome  octavo  volume. 

#9*  Publishing  in  the  "  MEDICAL  NEWS  AND  LIBRARY"  for  1873  and  1874. 

The  present  edition  of  Dr.  Wilson  Fox's  very  admi-  [  Dr.  Fox  has  put  forth  a  volume  of  uncommon  ex- 
rable  work  diners  from  the  preceding  in  that  it  deals  |  cellence,  which  we  feel  very  sure  will  take  a  higi 
with  other  maladies  than  dyspepsia  only.— London  j  rank  among  works  that  treat  o/  the  stoiaaeh.— Am. 
Med.  Times,  Feb.  8,  1873.  |  Practitioner,  March,  1873. 


jyRINTON  (WILLIAM],  M.D.,  F.R.S. 

^LECTURES  ON  THE  DISEASES  OF  THE  STOMACH;   with  an 

Introduction  on  its  Anatomy  and  Physiology.     From  the  second  and  enlarged  London  edi- 
tion.    With  illustrations  on  wood      In  one  handsome  octavo  volume  of  about  300 
extra  cloth.     $3  25. 


HENRY  C.  LEA'S  PUBLICATIONS — (Diseases  of  Lungs  and  Heart).     If 


(AUSTIN],  M.D., 

-*-'  Professor  of  the  Principles  and  Practice  of  Medicine  in  Bellevue  Hospital  Med.  College,  N.  Y. 

A  PRACTICAL  TREATISE  ON  THE  DIAGNOSIS,  PATHOLOGY, 

AND  TREATMENT  OF  DISEASES  OF   THE  HEART.     Second  revised  and  enlarged 
edition.     In  one  octavo  volume  of  550  pages,  with  a  plate,  extra  cloth,  $4. 

The  author  has  sedulously  improved  the  opportunity  afforded  him  of  revising  this  work.  Portions 
of  it  have  been  rewritten,  and  the  whole  brought  up  to  a  level  with  the  most  advanced  condition  of 
science.  It  must  therefore  continue  to  maintain  its  position  as  the  standard  treatise  on  the  subject. 

Dr.  Flint  chose  a  difficult  subject  for  his  researches, 
and  has  shown  remarkable  powers  of  observation 
and  reflection,  as  well  as  great  industry,  in  his  treat- 
ment of  it.  His  book  must  be  considered  the  fullest 
and  clearest  practical  treatise  on  those  subjects,  and 
should  be  in  the  hands  of  all  practitioners  and  stu- 
dents. It  is  a  credit  to  American  medical  literature. 


able  for  purposes  of  illustration,  in  connection  with 
cases  which  have  been  reported  by  other  trustworthy 
observers. — Brit,  and  For.  Med.-Chirurg.  Review. 


— Amer.  Journ.  of  the  Med.  Sciences,  July,  I860. 

We  question  the  fact  of  any  recent  American  author 
in  our  profession  being  more  extensively  known,  or 
more  deservedly  esteemed  in  this  country  than  Dr. 
Flint.  We  willingly  acknqwledge  his  success,  more 
particularly  in  the  volume  on  diseases  of  the  heart, 
In  making  an  extended  personal  clinical  study  avail- 


In  regard  to  the  merits  of  the  work,  we  have  DO 
hesitation  in  pronouncing  it  full,  accurate,  and  judi- 
cious. Considering  the  present  state  of  science,  such 
a  work  was  much  needed.  It  should  be  in  the  hands 
of  every  practitioner. — Chicago  Med.  Journ. 

With  more  than  pleasure  do  we  hail  the  advent  of 
this  work,  for  it  fills  a  wide  gap  on  the  list  of  text- 
books for  our  schools,  and  is,  for  the  practitioner,  the 
most  valuable  practical  work  of  its  kind. — N.  0.  Mtd. 
News. 


THE  SAME  A  UTHOR. 

L  PRACTICAL  TREATISE  OX  THE  PHYSICAL  EXPLORA- 
TION OF  THE  CHEST  AND  THE  DIAGNOSIS  OF  DISEASES  AFFECTING  THE 
RESPIRATORY  ORGANS.  Second  and  revised  edition.  In  one  handsome  octavo  volume 
of  595  pages,  extra  cloth,  $4  50. 


Dr.  Flint's  treatise  is  one  of  the  most  trustworthy 
guides  which  he  can  consult.  The  style  is  clear  and 
distinct,  and  is  also  concise,  being  free  from  that  tend- 
ency to  over-refinement  and  unnecessary  minuteness 
which  characterizes  many  works  on  the  same  sub- 
ject.— Dublin  Medical  Press,  Feb.  6,  1867. 

The  chapter  on  Phthisis  is  replete  with  interest ; 
and  his  remarks  on  the  diagnosis,  especially  in  the 
early  stages,  are  remarkable  for  their  acumen  and 
great  practical  value.  Dr.  Flint's  style  is  ciear  and 
elegant,  and  the  tone  of  freshness  and  originality 


which  pervades  his  whole  work  lend  an  additional 
force  to  its  thoroughly  practical  character,  which 
cannot  fail  to  obtain  for  it  a  place  as  a  standard  work 
on  diseases  of  the  respiratory  system. — London 
Lancet,  Jan.  19, 1S67. 

This  is  an  admirable  book.  Excellent  in  detail  and 
execution,  nothing  better  could  be  desired  by  the 
practitioner.  Dr.  Flint  enriches  his  subject  with 
much  solid  and  not  a  little  original  observation.— 
Ranking' s  Abstract,  Jan.  1867. 


FULLER  (HENRY  WILLIAM],  M.  D., 

•*-  Physician  to  St   George's  Hospital,  London. 

ON  DISEASES  OF  THE   LUNGS   AND   AIR-PASSAGES.     Their 

Pathology,  Physical  Diagnosis,  Symptoms,  and  Treatment.     From  the  second  and  revised 
English  edition.     In  one  handsome  octavo  volume  of  about  500  pages,  extra  cloth,  $3  50. 
Dr.  Fuller's  work  on  diseases  of  the  chest  was  so    accordingly  we  have  what  might  be  with  perfect  jus- 
favorably  received,  that  to  many  who  did  not  know    tice  styled  an  entirely  new  work  from  his  pen,  the 
the  extent  of  his  engagements,  it  was  a  matter  of  won-  i  portion  of  the  work  treating  of  the  heart  and  great 
der  that  it  should  be  allowed  to  remain  three  years  j  vessels  being  excluded.    Nevertheless,  this  volume  is 

improve  it,  j  of  almost  equal  size  with  the  first. — London  Medical 
Dr. 


out  of  print.     Determined,  however,  to  improve  it,    of  almost  equal  size  with  the  first 
Fuller  would  not  consent  to  a  mere  reprint,  and  I  Times  and  Gazette,  July  2C,  1867. 


WILLIAMS  (c.  j.  B.),  M.D., 

Senior  Consulting  Physician  to  the  Hospital  for  Consumption,  Brompton,  and 

WILLIAMS  (CHARLES  T.},  M.D., 

Physician  to  the  Hospital  for  Consumption. 

PULMONARY  CONSUMPTION;  Its  Nature,  Varieties,  and  Treat- 
ment. With  an  Analysis  of  One  Thousand  cases  to  exemplify  its  duration.  In  one  neat 
octavo  volume  of  about  350  pages,  extra  cloth.  (Just  Issued.)  $2  50. 


He  can  still  speak  from  a  more  enormous  experi- 
ence, and  a  closer  study  of  the  morbid  processes  in- 
volved iu  tuberculosis,  than  most  living  men.  He 
owed  it  to  himself,  and  to  the  importance  of  the  sub- 
ject, to  embody  his  views  in  a  separate  work,  and 
we  are  glad  that  he  has  accomplished  this  duty. 
After  all,  the  grand  teaching  which  Dr  Williams  has 
for  the  profession  is  to  be  found  in  hi*  therapeutical 
chapters,  and  in  the  history  of  individual  cases  ex- 
tended, by  dint  of  care,  over  ten,  twenty,  thirty,  and 
even  forty  years. — London  Lancet,  Oct.  21,  1871. 

His  results  are  more  favorable  than  those  of  any 


previous  author;  but  probably  there  is  no  malady, 
the  treatment  of  which  has  been  so  much  improved 
within  the  last  twenty  years  as  pulmonary  consump- 
tion. To  ourselves,  Dr.  Williams's  chapters  on  Treat- 
ment are  amongst  the  most  valuable  and  attractive  in 
the  book,  and  would  alone  render  it  a  standard  work 
of  reference.  In  conclusion,  we  would  record  our 
opinion  that  Dr.  Williams's  great  reputation  is  fully 
maintained  by  this  book.  It  is  undoubtedly  one  of 
the  most  valuable  works  in  the  language  upon  any 
special  disease. — Lond.  Med.  Times  and  Gaz.,  Nov. 
4,  1871. 


LA   ROCHE  ON  PNEUMONIA.     1  vol.  8vo.f  extra 

cloth,  of  500  pages.     Price $3  00. 
BUCKLER  ON   FIBRO-BRONCHITIS  AND  RHEC- 

MATIC  PNEUMONIA.     1  vol.  8vo.     $1  25. 
FISKE  FUND  PRIZE  ESSAYS  ON  CONSUMPTION. 
'  1  vol  8vo,,  extra  cloth.    $1  00. 


SMITH  ON  CONSUMPTION  ;  ITS  EARLY  AND  RE- 
MEDIABLE  STAGES.  1  vol.  8vo.,  pp.  254.  $2  25. 

WALSHE  ON  THE  DISEASES  OF  THE  HEART  AND 
GREAT  VESSELS.  Third  American  edition.  In 
1  vol.  Svo..  420  pp.,  cloth.  $3  00. 


18 


HENRY  C.  LEA'S  PUBLICATIONS — (Practice  of  Medicine). 


ROBERTS  (  WILLIAM],  M.  D.. 

•*•*'  Lecturer  on  Medicine  in  the  Manchester  School  of  Medicine,  &c. 

A  PRACTICAL  TREATISE   ON  URINARY  AND   RENAL   DIS- 

EASES,  including  Urinary  Deposits.  Illustrated  by  numerous  cases  and  engravings.  Sec- 
ond American,  from  the  Second  Revised  and  Enlarged  London  Edition.  In  one  large 
and  handsome  octavo  volume  of  616  pages,  with  a  colored  plate  ;  extra  cloth,  $4  50.  (Just 
Issued.) 

The  author  has  subjected  this  work  to  a  very  thorough  revision,  and  has  sought  to  embody  in 
it  the  results  of  the  latest  experience  and  investigations.  Although  every  effort  has  been  made 
to  keep  it  within  the  limits  of  its  former  size,  it  has  been  enlarged  by  a  hundred  pages,  many 
new  wood-cuts  have  been  introduced,  and  also  a  colored  plate  representing  the  appearance  of  the 
different  varieties  of  urine,  while  the  price  has  been  retained  at  the  former  very  moderate  rate. 


The  plan,  it  will  thus  be  seen,  is  very  complete, 
an  I  the  manner  in  which  it  has  been  carried  out  is 
in  the  highest  degree  satisfactory.  The  characters 
of  the  different  deposits  are  very  well  described,  and 
the  microscopic  appearances  they  present  are  illus- 
trated by  numerous  well  executed  engravings.  It 
only  remains  to  ns  to  strongly  recommend  to  our 
readers  Dr.  Roberts's  work,  as  containing  an  admira- 
ble r>'.<<um.e  of  the  present  state  of  knowledge  of  uri- 
nary diseases,  and  as  a  safe  and  reliable  guide  to  the 
clinical  observer. — Edin.  Med.  Jour. 

The  most  complete  and  practical  treatise  upon  renal 


diseases  we  have  examined.  It  is  peculiarly  adapted 
to  the  wants  of  the  majority  of  American  practition- 
ers from  its  clearness  and  simple  announcement  of  the 
facts  in  relation  to  diagnosis  and  treatment  of  urinary 
disorders,  and  contains  in  condensed  form  the  investi- 
gations of  Bence  Jones,  Bird,  Beale,  Hassall,  Front, 
and  a  host  of  other  well-kuown  writers  upon  this  sub- 
ject. The  characters  of  urine,  physiological  and  pa- 
thological, as  indicated  to  the  naked  eye  as  well  as  by 
microscopical  and  chemical  investigations,  are  con- 
cisely represented  both  by  description  and  by  well 
executed  engravings. — Cincinnati  Journ.  of  Med. 


&ASHAM  (W.R.),  M.D., 

J-J  Senior  Physician  to  the  Westminster  Hospital,  &c. 

REN  AL  DISEASES :  a  Clinical  Guide  to  their  Diagnosis  and  Treatment. 

With  illustrations.     In  one  neat  royal  12mo.  volume  of  304  pages.    $2  00. 


The  chapters  on  diagnosis  and  treatment  are  very 

food,  and  the  student  and  young  practitioner  will 
nd  them  full  of  valuable  practical  hiuts.  The  third 
part,  on  the  urine,  is  excellent,  and  we  cordially 
recommend  its  perusal.  The  author  has  arranged 
his  matter  in  a  somewhat  novel,  and,  we  think,  use- 
ful form.  Here  everything  can  be  easily  found,  and, 
what  is  more  important,  easily  read,  for  all  the  dry 


details  of  larger  books  here  acquire  a  new  interest 
from  the  author's  arrangement.  This  part  of  the 
book  is  full  of  good  work.— Brit,  and  For.  Medico- 
Vhirurgical  Review,  July,  1870. 

The  easy  descriptions  and  compact  modes  of  state- 
ment, render  the  book  pleasing  and  convenient. — Arn. 
Journ.  Med.  Sciences,  July,  1870. 


ON    FUNCTIONAL   NERVOUS 

In  one  handsome  octavo  volume  of  348  pages, 


TONES  (C.  HANDFIELD],  M.  D., 

*J  Physician  to  St.  Mary's  Hospital,  &c. 

CLINICAL    OBSERVATIONS 

DISORDERS.     Second  American  Edition, 
extra  cloth,  $3  25. 

Taken  as  a  whole,  the  work  before  ns  furnishes  a  I  titioner  will  derive  from  it  many  a  suggestive  bint  to 
ehort  but  reliable  account  of  the  pathology  and  treat-     aid  him  in  the  diagnosis  of  "nervous  cases,"  and  in 
ment  of  a  class  of  very  common  but  certainly  highly  I  determining  the  true  indications  for  their  ameliora- 
obscure  disorders.    The  advanced  student  will  find  it  I  tion  or  cure.—  Amer.  Journ.  Med.  Sci.,  Jan.  1867. 
a  rich  mine  of  valuable  facts,  while  the  medical  prac-  I 


T  INCOLN  (D.  F.}.  M.D., 

-L-*  Physician  to  the.  Department  of  Nervous  Diseases,  Boston  Dispensary. 

ELECTRO  THERAPEUTICS;  4  Concise  Manual  of  Medical  Electri- 

city.     In  one  very  neat  royal  12mo.  volume,  with  Illustrations. 

The  chief  aim  cf  the  present  volume  has  been  the  analysis  of  the  principles  which  ought  to 
govern  our  use  of  Electricity.  The  portions  describing  the  practical  applications  which  have  been 
made  of  it  in  various  disorders,  may  be  found  incomplete,  but  it  is  hoped  that  enough  has  been 
said  to  satisfy  the  needs  of  the  general  practitioner.  —  PREFACE. 


CHAPTER  I.  Physical  Laws.  —  II.  Modes  of  Generating  Electricity.  —  III.  Physiology  —  TV. 
Diagnosis.  —  V.  Methods  of  Applying  Electricity.  —  VI.  Medical  and  Surgical  Practice.  —  VII. 
Cautions.  —  VIII.  Apparatus. 

gLADE  (D.  D.),  M.D. 

DIPHTHERIA;  its  Nature  and  Treatment,  with  an  account  of  the  His- 

tory of  its  Prevalence  in  various  Countries.     Second  and  revised  edition.     In  one  neat 
royal  12mo.  volume,  extra  cloth.     $1  25. 


TTUDSON(A.},  M.  D.,  M.  R.  1.  A., 

*-J-        Physician  to  the  Meath  Hospital. 


Physician  to  the  Meath  Hospital. 

LECTURES  ON  THE   STUDY  OF  FEVER. 

Cloth,  $2  50. 


In  one  vol.  8vo.,  extra 


TYONS  (ROBERT  D.},  K.  C.  C. 
A  TREATISE  ON   FEVER. 

cloth.     $2  25. 


In  one  octavo  volume  of  362  pages  ; 


HENRY  C.  LEA'S  PUBLICATIONS — (  Venereal  Diseases,  etc.). 


19 


f>UMSTEAD  (FREEMAN  J.},  M.D., 

-*-'         Professor  of  Venereal  Diseases  at  the  Col.  of  Phys  and  Surg.,  New  York,  &c. 

THE  PATHOLOGY  AND  TREATMENT  OF  VENEREAL  DIS- 
EASES. Including  the  results  of  recent  investigations  upon  the  subject.  Third  edition, 
revised  and  enlarged,  with  illustrations.  In  one  large  and  handsome  octavo  volume  of 
over  700  pages,  extra  cloth,  $5  00  ;  leather,  $ti  00.  (Jnsi  Issued.} 

In  preparing  this  standard  work  again  for  the  press,  the  author  has  subjected  it  to  a  very 
thorough  revision.  Many  portions  have  been  rewritten,  and  much  new  matter  added,  in  order  to 
bring  it  completely  on  a  level  with  the  most  advanced  condition  of  syphilograpby,  but  by  careful 
compression  of  the  text  of  previous  editions,  the  work  has  been  increased  by  only  sixty -four  pages. 
The  labor  thus  bestowed  upon  it,  it  is  hoped,  will  insure  for  it  a  continuance  of  it»  position  as  a 
complete  and  trustworthy  guide  for  the  practitioner. 

It  is  the  most  complete  book  with  which  we  are  ac- 
quainted in  the  language.  The  la.te.st  views  of  the 
best  authorities  are  put  forward,  and  the  information 
is  well  arranged — a  great  point  for  the  student,  and 
still  more  for  the  practitioner.  The  subjects  of  vis- 
ceral syphilis,  syphilitic  affections  of  the  eyes,  and 


the  treatment  of  syphilis  by  repeated  inoculations,  are 
ry  fully  discussed. — London  Lanctt.  Jan   7,  IS71. 


much  special  commendation  as  if  its  predecessors  had 
not  been  published.  As  a  thoroughly  practical  book 
on  a  class  of  diseases  which  form  a  large  share  of 
nearly  every  physician's  practice,  the  volume  before 
us  is  by  far  the  best  of  which  we  have  knowledge.— 
N.  Y.  Medical  Gmette,  Jan.  28,  1871. 

It  is  rare  in  the  history  of  medicine  to  find  any  one 
book  which  contains  all  that  a  practitioner  needs  to 


Dr.    Bumstead's   work   is  already  so  universally  know;  while  the  possessor  of  "Bumstead  on  Vene- 

known  as  the  best  treatise  in  the  English  language  on  real"  has  no  occasion  to  look  outside  of  its  covers  for 

venereal  diseases,  that  it  may  seern  almost  -uperflu-  anything  practical  connected  with  the  diagnosis,  his- 

ous  to  say  more  of  it  than  that  a  new  edition  has  been  tory,  or  treatment  of  these  affections.  —  AT.  ¥  Medical 

issued.     But  the  author's  industry  has  rendered  this  Journal.  March,  1871. 
new  edition  virtually  a  new  work,  and  so  merits  H* 


SIULLERIER  (A.),  and 

V/         Surgeon  to  the  Hdpital  du  Midi. 


BUM  ME  AD  (FREEMAN  J.}, 

•*-*        Professor  of  Venereal  Diseases  in  the  College  of 
Physicians  and  Surgeons,  N.  Y 

AN  ATLAS  OF  VENEREAL  DISEASES.     Translated  and  Edited  by 

FREEMAN  J.  BUMSTEAD.  In  one  large  imperial  4to.  volume  of  328  pages,  double-columns, 
with  26  plates,  containing  about  150  figures,  beautifully  eolored,  many  of  them  the  size  of 
life;  strongly  bound  in  extra  cloth,  $17  00;  also,  in  five  parts,  stout  wrappers  for  mailing,  at 
$3  per  part.  (Lately  Published.) 

Anticipating  a  very  large  sale  for  this  work,  it  is  offered  at  the  very  low  price  of  THREE  DOL- 
LARS a  Part,  thus  placing  it  within  the  reach  of  all  who  are  interested  in  this  department  of  prac- 
tice.    Gentlemen  desiring  early  impressions  of  the  plates  would  do  well  to  order  it  without  delay. 
A  specimen  of  the  plates  and  text  sent  free  by  mail,  on  receipt  of  25  cents. 
We  wish  for  once  that  our  province  was  not  restrict-  \  which  for  its  kind  is  more  necessary  for  them  to  have. 


ed  to  methods  of  treatment,  that  we  might  say  some- 
thing of  the  exquisite  colored  plates  in  this  volume. 
—  London  Practitioner,  May,  1869. 

As  a  whole,  it  teaches  all  that  can  be  taught  by 
means  of  plates  and  print. — London  Lancet,  March 
13,  I860. 

Superior  to  anything  of  the  kind  ever  before  issued 
on  this  continent — Canada  Me'l.  Journal,  March,  '69. 

The  practitioner  who  desires  to  understand  this 
branch  of  medicine  thoroughly  should  obtain  this, 
the  most  complete  and  best  work  ever  published.— 
Dominion  Med.  Journal,  May,  1869. 

This  is  a  work  of  master  ha.nds  on  both  sides.  M. 
Cullerier  is  scarcely  second  to,  we  think  we  may  truly 
say  is  a  peer  of  the  illustrious  and  venerable  Ricord, 
while  in  this  country  we  do  not  hesitate  to  say  that 
Dr.  Bumstead,  as  an  authority,  is  without  a  rival 
Assuring  our  readers  that  these  illustrations  tell  the 
whole  history  of  venereal  disease,  from  its  inception 
to  its  end,  we  do  not  know  a  single  medical  work, 


-California  Med.  Gazette,  March,  1869. 

The  most  splendidly  illustrated  work  in  the  lan- 
guage, and  in  our  opinion  far  more  useful  than  the 
French  original — Am.  Journ.  Med.  Sciences,  Jan. '69. 

The  fifth  and  concluding  number  of  this  magnificent 
work  has  reached  us,  and  we  have  no  hesitation  in 


tying  that  its  illu>trat 


rpass  those  of  previous 


numbers.— Boston  Med.  and  Surg.  Journal,  Jan.  14, 
1869. 

Other  writers  besides  M.  Cullerier  have  given  us  a 
good  account  of  the  diseases  of  which  he  treats,  but 
no  one  has  furnished  us  with  such  a  complete  series 
of  illustrations  of  the  venereal  diseases.  There  is, 


however,  an  additional  i 


ind  value  possessed 


by  the  volume  before  us  ;  for  it  is  an  American  reprint 
and  translation  of  M.  Cullerier's  work,  with  inci- 
dental remarks  by  one  of  the  most  eminent  American 
philographers,  Mr.  Bumstead.  —Brit,  and  For. 


edico-  Chir.  Review,  July,  1869. 


7LL  (BERKELEY), 

Surgeon  to  the  Lock  Ho^ital,  London. 

ON  SYPHILIS  AND   LOCAL  CONTAGIOUS   DISORDERS. 

one  handsome  octavo  volume  :  extra  cloth,  $3  25.     (Lately  Published.) 


In 


Bringing,  as  it  does,  the  entire  literature  of  the  dis- 
ease down  to  the  present  day,  and  giving  with  great 
ability  the  results  of  modern  research,  it  is  in  every 
respect  a  most  desirable  work,  and  one  which  should 
find  a  place  in  the  library  of  every  surgeon.— Cali- 
fornia Med.  Gazette,  June,  1869. 

Considering  the  scope  of  the  book  and  the  careful 
attention  to  the  manifold  aspects  and  details  of  its 


to  whom  we  would  most  earnestly  recommend  its 
study  ;  while  it  is  no  less  useful  to  the  practitioner.— 
fit.  Louis  Med.  and  Surg.  Journal,  May,  1869. 

The  most  convenient  and  ready  book  of  reference 
We  have  met  with.— M  Y.  Med.  Record,  May  1,1869. 

Most  admirably  arranged  for  both  student  and  prac- 
titioner, no  other  work  on  the  subject  equals  it ;  it  is 


_          _    _  HUH     Uoletlifc    Ul     lio       niiwucij    u\j  vn-ioi  j^^jv^-  --^ -  ,      - 

•ubjecMt  is  wonderfully  concise.     All  these  qualities    more  simple,  more  easily  studied.—  Buffalo  Med.  and 
render  it  an  especially  valuable  book  to  the  beginner,  I  Surg.  Journal,  March,  1S69. 

r/EISSL  (#.),  M.D. 

^  A  COMPLETE  TREATISE  OX  VENEREAL  DISEASES.  Trans- 
lated from  the  Second  Enlnrged  Gerrann  Edition,  by  FREDERIC  R.  STURGIS,  M.D  In  one 
octavo  volume,  with  illustrations.  (Preparing.) 


20 


HENRY  C.  LEA'S  PUBLICATIONS — (Diseases  of  the  Skin). 


WILSON  (ERASMUS],  F.R.S. 

ON  DISEASES  OF  THE  SKIN.  With  Illustrations  on  wood.  Sev- 
enth American,  from  the  sixth  and  enlarged  English  edition.  In  one  large  octavo  volume 
of  over  800  pages,  $5. 

A  SERIES  OF  PLATES  ILLUSTRATING  "WILSON  ON  DIS- 
EASES OP  THE  SKIN;"  consisting  of  twenty  beautifully  executed  plates,  of  which  thir- 
teen are  exquisitely  colored,  presenting  the  Normal  Anatomy  and  Pathology  of  the  Skin, 
and  embracing  accurate  representations  of  about  one  hundred  varieties  of  disease,  most  of 
them  the  size  of  nature.  Price,  in  extra  cloth,  $5  50. 

Also,  the  Text  and  Plates,  bound  in  one  handsome  volume.     Extra  cloth,  $10. 


No  one  treating  skin  diseases  should  be  without 
a  copy  of  this  standard  work. —  Canada  Lancet. 

We  can  safely  recommend  it  to  the  profession  at 
the  best  work  on  the  subject  now  in,  existence  ir 
the  English  language.— Medical  Times  and  Gazette 

Mr.  Wilson's  volume  is  an  excellent  digest  of  the 
actual  amount  of  knowledge  of  cutaneous  diseases : 
it  includes  almost  every  fact  or  opinion  of  importance 
connected  with  the  anatomy  and  pathology  of  the 
skin.—  British  and  Foreign  Medical  Review. 

Such  a  work  as  the  one  before  us  is  a  most  capital 


and  acceptable  help.  Mr.  Wilson  has  long  been  held 
as  high  authority  in  this  department  of  medicine,  and 
his  book  on  diseases  of  the  skin  has  long  been  re- 
garded as  one  of  the  best  text-books  extant  on  the 
subject.  The  present  edition  is  carefully  prepared, 
and  brought  up  in  its  revision  to  the  present  time  In 
'his  edition  we  have  also  included  the  beautiful  series 
of  plates  illustrative  of  the  text,  and  in  the  last  edi- 
tion published  separately.  There  are  twenty  of  these 
plates,  nearly  all  of  them  colored  to  nature,  and  ex- 
hibiting with  great  fidelity  the  various  groups  of 
diseases. — Cincinnati  Lancet. 


Y  THE  SAME  AUTHOR.  

THE  STUDENT'S  BOOK  OF  CUTANEOUS  MEDICINE  and  DIS- 
EASES OF  THE  SKIN.   In  one  very  handsome  royal  12mo.  volume.  $350.    (Lately  Issued.) 


ffELIGAN  (J.  MOORE),  M.D.,  M.R.I. A. 

A    PRACTICAL    TREATISE    ON    DISEASES    OF    THE    SKIN. 

Fifth  American,  from  the  second  and  enlarged  Dublin  edition  by  T.  W.  Belcher,  M.D. 
In  one  neat  royal  12mo.  volume  of  462  pages,  extra  cloth.     $2  25. 

Fully  equal  to  all  the  requirements  of  students  and  |  k,heir  value  justly  estimated  ;  in  a  word,  the  work  is 
young  practitioners. — Dublin  Med.  Press.  fully  up  to  the  times,  and  is  thoroughly  stocked  with 

Of  the  remainder  of  the  work  we  have  nothing  be-    most  valuable  information.— New  York  Med.  Record, 
yond  unqualified  commendation  to  offer.     It  is  so  far 
the  most  complete  one  of  its  size  that  has  appeared, 


and  for  the  student  there  can  be  none  which  can  com- 


Jan.  15,  1867. 
The   most  convenient  manual  of  diseases  of  the 


skin  that  can  be  procureo  by  the  student.  —  Chicago 


pare  with  it  in  practical  value.     All  the  late  disco-     Med.  Journal,  Dec.  1866. 
veries  in  Dermatology  have  been  duly  noticed,  and  | 
fiY  THE  SAME  AUTHOR. 

ATLAS   OF   CUTANEOUS    DISEASES.      In   one  beautiful   quarto 

volume,  with  exquisitely  colored  plates,  <fcc.,  presenting  about  one  hundred  varieties  of 
disease.     Extra  cloth,  $5  50. 

The  diagnosis  of  eruptive  disease,  however,  under  I  inclined  to  consider  it  a  very  superior  work,  corn- 
all  circumstances,  is    very  difficult.     Nevertheless,  |  bining  accurate  verbal  description  with  sound  views 


Dr.  Neligan  has  certainly,  "as  far  as  possible,'' given 
a  faithful  and  accurate  representation  of  this  class  of 
diseases,  and  there  can  be  no  doubt  that  these  plates 
will  be  of  great  use  to  the  student  and  practitioner  in 
drawing  a  diagnosis  as  to  the  class,  order,  and  species 
to  which  the  particular  case  may  belong.  While 
looking  over  the-"Atlas"  we  have  been  induced  to 
examine  also  the  "Practical  Treatise,"  and  we  are 


of  the  pathology  and  treatment  of  eruptive  diseases. 
— Glasgow  Med.  Journal. 

A  compend  which  will  very  much  aid  the  practi- 
tioner in  this  difficult  branch  of  diagnosis  Taken 
with  the  beautiful  plates  of  the  Atlas,  which  are  re- 
markable for  their  accuracy  and  beauty  of  coloring, 
it  constitutes  a  very  valuable  addition  to  the  library 
of  a  practical  man. — Buffalo  Med.  Journal. 


TJILLIER  (THOMAS],  M.D., 

-*•-*•  Physician  to  the  Skin  Department  of  University  College  Hospital,  &c. 

HAND-BOOK  OF  SKIN  DISEASES,  for  Students  and  Practitioners. 

Second  American  Edition.     In  one  royal  12mo.  volume  of  358  pp.     With  Illustrations. 
Extra  cloth,  $2  25. 


We  can  conscientiously  recommend  it  to  the  stu- 
dent;  the  style  is  clear  and  pleasant  to  read,  the 
matter  is  good,  and  the  descriptions  of  disease,  with 
the  modes  of  treatment  recommended,  are  frequently 
Illustrated  with  well-recorded  cases.  —  London  Med. 
Times  and  Gazette,  April  1,  1865. 


It  is  a  concise,  plain,  practical  treatise  on  the  vari- 
ous  diseases  of  the  skin  ;  just  such  a  work,  indeed, 
as  was  much  needed,  both  by  medical  students  and 


practitioners.  —  Chicago   Medical  Examiner, 

1865. 


May, 


A  NDERSON  (McCALL],  M.D., 

-*-*-  Physician  to  the  Dispensary  for  Skin  Diseases,  Glasgow,  &c. 

ON  THE  TREATMENT  OF  DISEASES  OF  THE  SKIN.     With  an 

Analysis  of  Eleven  Thousand  Consecutive  Cases.     In  one  vol.  8vo.     $1.      (Just  Ready,) 


GUERSANT'S  SURGICAL  DISEASES  OF  INFANTS 
AND  CHILDREN.  Translated  by  R.  J.  DD.KGLI- 
SON,  M.D.  1  vol.  8vo.  Cloth,  $2  50. 


DEWEES  ON  THE  PHYSICAL  AND  MF,mrAL 
TREATMENT  OT?  CHILDRKN  Eleventh  edition. 
1  vo).  <*vo.  of  548  pages.  $2  80. 


HENRY  C.  LEA'S  PUBLICATIONS — (Diseases  of  Children).  21 

VMITH  (J.  LE  WIS),  M.  D., 

*J  Professor  of  Morbid  Anatomy  in  the  Bellevue  Hospital  Med.  College,  N.  Y. 

A  COMPLETE  PRACTICAL  TREATISE  ON  THE  DISEASES  OF 

CHILDREN.     Second  Edition,  revised  and  greatly  enlarged.     In  one  handsome  octavo 
volume  of  742  pages,  extra  cloth,  $5;  leather,  $6.     (Just  Issued.) 
FROM  THE  PREFACE  TO  THE  SECOND  EDITION. 

In  presenting  to  the  profession  the  second  edition  of  his  work,  the  author  gratefully  acknow- 
ledges the  favorable  reception  accorded  to  the  first.  He  has  endeavored  to  merit  a  continuance 
of  this  approbation  by  rendering  the  volume  much  more  complete  than  before.  Nearly  twenty 
additional  diseases  have  been  treated  of,  among  which  may  be  named  Diseases  Incidental  to 
Birth,  Rachitis,  Tuberculosis,  Scrofula,  Intermittent,  Remittent,  and  Typhoid  Fevers,  Chorea, 
and  the  various  forms  of  Paralysis.  Many  new  formulae,  which  experience  has  shown  to  be 
useful,  have  been  introduced,  portions  of  the  text  of  a  less  practical  nature  have  been  con- 
densed, and  other  portions,  especially  those  relating  to  pathological  histology,  have  been 
rewritten  to  correspond  with  recent  discoveries.  Every  effort  has  been  made,  however,  to  avoid 
an  undue  enlargement  of  the  volume,  but,  notwithstanding  this,  and  an  increase  in  the  size  of 
the  page,  the  number  of  pages  has  been  enlarged  by  more  than  one  hundred. 

227  WEST  49TH  STREET,  NEW  YORK,  April,  1872. 

The  work  will  be  found  to  contain  nearly  one-third  more  matter  than  the  previous  edition,  and 
it  is  confidently  presented  as  in  every  respect  worthy  to  be  received  as  the  standard  American 
text-book  on  the  subject. 


Eminently  practical  as  well  as  judicious  In  its 
teachings. — Cincinnati  Lancet  and  Obs.,  July,  1872. 

A  standard  work  that  leaves  little  to  be  desired. — 
Indiana  Journal  of  Medicine,  July,  1872. 

We  know  of  no  book  on  this  subject  that  we  can 
more  cordially  recommend  to  the  medical  studeut 
and  the  practitioner.— Cincinnati  Clinic,  June  29,  '72. 


We  regard  it  as  superior  to  any  other  single  work 
on  the  diseases  of  infancy  and  childhood. — Detroit 
Rev.  of  Med.  and  Pharmacy,  Aug.  1872. 

We  confess  to  increased  enthusiasm  in  recommend- 
ing this  second  editioa. — St  Louis  Med.  and  Surg. 
Journal,  Aug.  1872. 


ffONDIE  (D.  FRANCIS),  M.  D. 

A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  CHILDREN. 

Sixth  edition,  revised  and  augmented.     In  one  large  octavo  volume  of  nearly  800  closely- 
printed  pages,  extra  cloth,  $5  25  ;  leather,  $6  25.       (Lately  Issued.) 


The  present  edition,  which  is  the  sixth,  is  fully  up 
to  the  times  in  the  discussion  of  all  those  points  in  the 
pathology  and  treatment  of  infantile  diseases  which 
have  been  brought  forward  by  the  German  and  French 


teachers.  As  a  whole,  however,  the  work  is  the  best 
American  one  that  we  have,  and  in  its  special  adapta- 
tion to  American  practitioners  it  certainly  has  no 
equal.  —  New  York  Med.  Record,  March  2,  1868. 


WEST  (CHARLES),  M.D., 

Physician  to  the  Hospital  for  Sick  Children,  &c. 

LECTURES  ON   THE   DISEASES   OF   INFANCY  AND  CHILD- 

HOOD.     Fifth  American  from  the  sixth  revised  and  enlarged  English  edition.     In  one  large 
and  handsome  octavo  volume  of  678  pages.     Cloth,  $4  50  ;  leather,  $5  50.     (Just  Ready.) 
The  continued  demand  for  this  work  on  both  sides  of  the  Atlantic,  and  its  translation  into  Ger- 
man, French,  Italian,  Danish,  Dutch,  and  Russinn,  show  that  it  fills  satisfactorily  a  want  exten- 
sively felt  by  the  profession.     There  is  probably  no  man  living  who  can  speak  with  the  authority 
derived  from  a  more  extended  experience  than  Dr.  West,  and  his  work  now  presents  the  results  of 
nearly  2000  recorded  cases,  and  600  post-mortem  examinations  selected  from  among  nearly  40,000 
cases  which  have  passed  under  his  care.      In  the  preparation  of  the  present  edition  he  has  omitted 
much  that  appeared  of  minor  importance,  in  order  to  find  room  for  the  introduction  of  additional 
matter,  and  the  volume,  while  thoroughly  revised,  is  therefore  not  increased  materially  in  size. 

Of  all  the  English  writers  on  the  diseases  of  chil-  I  living  authorities  in  the  difficult  department  of  medi- 
dren,  there  is  no  one  so  entirely  satisfactory  to  us  as  |  cal  science  in  which  he  is  most  widely  known.— 
Dr.  West.    For  years  we  have  held  his  opinion  as    Boston  Med.  and  Surg.  Journal. 
judicial,  and  have  regarded  him  as  one  of  the  highest  | 

Dr  THE  SAME  AUTHOR.    (Lately  Issued.) 

ON  SOME  DISORDERS  OF  THE  NERVOUS  SYSTEM  IN  CHILD- 
HOOD; being  the  Lumleian  Lectures  delivered  at  the  Royal  College  of  Physicians  of  Lon- 
don, in  March,  1871.  In  one  volume,  small  12mo.,  extra  cloth,  $1  00. 

VMITH (EUSTACE),  M.  D., 

Physician  to  the  Northwest  London  Free  Dispensary  for  Sick  Children. 

A  PRACTICAL  TKEATISE  ON   THE  WASTING   DISEASES  OF 

INFANCY  AND  CHILDHOOD.     Second  American,  from  the  second  revised  and  enlarged 
English  edition.     In  one  handsome  octavo  volume,  extra  cloth,  $2  50.     (Lately  Itsued.) 


This  is  in  every  way  an  admirable  book.  Th 
modest  title  which  the  author  has  chosen  for  it  scarce- 
ly conveys  an  adequate  idea  of  the  many  subjects 
upon  which  it  treats.  Wasting  is  so  constant  an  at- 
tendant upon  the  maladies  of  childhood,  that  a  trea- 
tise upon  the  wasting  diseases  of  children  must  neces 
garily  embrace  the  consideration  of  many  affections 


of  which  it  is  a  symptom  ;  and  this  is  excellently  well  1  April  8,  1871. 
done  by  Dr.  Smith.    The  book  might  fairly  be  de- 


scribed as  a  practical  handbook  of  the  common  dis- 
eases of  children,  so  numerous  are  the  affections  con- 
sidered either  collaterally  or  directly.  We  are 
acquainted  with  no  safer  guide  to  the  treatment  of 
children's  diseases,  and  few  works  give  the  insight 
into  the  physiological  and  other  peculiarities  of  chil- 
dren that  Dr.  Smith's  book  does.— Brit.  Med.Journ., 


22  HENRY  C.  LEA'S  PUBLICATIONS — (Diseases  of  Women). 

Y 


HE  OBSTETRICAL  JOURNAL. 

THE  OBSTETRICAL  JOURNAL  of  Great  Britain  and  Ireland; 
Including  MIDWIFERY,  and  the  DISEASES  OP  WOMEN  AND  INFANTS.  With  an  American 
Supplement,  edited  by  WILLIAM  F.  JENKS,  M.D.  A  monthly  of  about  80  octavo  pages, 
very  handsomely  printed.  Subscription,  Five  Dollars  per  annum.  Single  Numbers,  50 
cents  each. 

Commencing  with  April,  1873,  the  Obstetrical  Journal  consists  of  Original  Papers  by  Brit- 
ish and  Foreign  Contributors  ;  Transactions  of  the  Obstetrical  Societies  in  England  and  abroad  ; 
Reports  of  Hospital  Practice;  Reviews  and  Bibliographical  Notices;  Articles  and  Notes,  Edito- 
rial, Historical,  Forensic,  and  Miscellaneous;  Selections  from  Journals;  Correspondence,  Ac. 
Collecting  together  the  vast  amount  of  material  daily  accumulating  in  this  important  and  ra- 
pidly improving  department  of  medical  science,  the  value  of  the  information  which  it  pre- 
sents to  the  subscriber  may  be  estimated  from  the  character  of  the  gentlemen  who  have  already 
promised  their  support,  including  such  names  as  tho^e  of  Drs.  ATTHILL,  ROBERT  BARNES,  HENRY 
BENNET,  THOMAS  CHAMBERS,  FLEKTWOOD  CHURCHILL,  MATTHEWS  DUNCAN,  GRAILY  HEWITT, 
BRAXTON  HICKS,  ALFRED  MEADOWS,  W.  LEISHMAN,  ALEX.  SIMPSON,  TYLER  SMITH,  EDWARD  J. 
TILT,  SPENCER  WELLS,  Ac.  &c.  ;  in  short,  the  representative  men  of  British  Obstetrics  and  Gynae- 
cology. 

In  order  to  render  the  OBSTETRICAL  JOURNAL  fully  adequate  to  the  wants  of  the  American 
profession,  each  number  contains  a  Supplement  devoted  to  the  advances  made  in  Obstetrics  and 
Gynaecology  on  this  side  of  the  Atlantic.  This  portion  of  the  Journal  is  under  the  editorial 
charge  of  Dr.  WILLIAM  F.  JENKS,  to  whom  editorial  communications,  exchanges,  books  for  re- 
view, &a.,  may  be  addressed,  to  the  care  of  the  publisher. 

*a*  Complete  sets  from  the  beginning  can  no  longer  be  furnished,  but  subscriptions  can  com- 
mence with  January,  1874,  or  with  Vol.  II.,  April,  1874. 


fTHOMAS  (T.  GAILLARD},M.D., 

•*-  Professor  of  Obstetrics,  &c.,  in  the  College  of  Physicians  and  Surgeons,  N.  Y.,  &c. 

A  PRACTICAL  TREATISE  ON  THE  DISEASES  OF  WOMEN.    Third 

edition,  enlarged  and  thoroughly  revised.     In  one  large  and  handsome  octavo  volume  of 
784  pages,  with  246  illustrations.     Cloth,  $5  00;  leather,  $6  00.     (Lately  Issued.) 
The  author  has  taken  advantage  of  the  opportunity  afforded  by  the  call  for  another  edition  of 
this  work  to  render  it  worthy  a  continuance  of  the  very  remarkable  favor  with  which  it  has  been 
received.     Every  portion  has  been  subjected  to  a  conscientious  revision,  several  new  chapters 
have  been  added,  and  no  labor  spared  to  make  it  a  complete  treatise  on  the  most  advanced  con- 
dition of  its  important  subject.     The  present  edition  therefore  contains  about  one-third   more 
matter  than  the  previous  one,  notwithstanding  which  the  price  has  been  maintained  at  the  former 
very  moderate  rate,  rendering  this  one  of  the  cheapest  volumes  accessible  to  the  profession. 

As  compared  with  the  first  edition,  five  new  chap-  We  are  free  to  say  that  we  regard  Dr.  Thomas  the 
ters  on  dysrnenorrhoea,  peri-uterine  fluid  tumors,  best  American  autlmrity  on  diseases  of  women.  Seve- 
composite  tumors  of  the  ovary,  solid  tumor*  of  the  ;  ral  others  have  written,  and  written  well,  but  none 
ovary,  and  chlorosis,  have  been  added.  Twenty- {  have  so  clearly  an<1  carefully  arranged  their  text  a  nd 
seven  additional  wood-cuts  have  been  introduced,  '  instruction  as  Dr.  Thomas.— Cincinnati  Lancet  and 
many  subjects  have  been  subdivided,  and  all  have  Observer,  May,  1S72. 

received  impor.ant  interstitial  increase      In  fact,  the        We  deem  it  scarcely  necessary  to  recommend  this 
b..ok  has  been  practically  rewritten,  and  greatly  in-     work  to  physicians  a*  it  is  now  widely  known,  and 
creased  in  value      Briefly,  we  may  say  that  we  know     most  of  them  .diready  possess  it,  or  will  certainly  do 
of  no  book  which  so  completely  and  concisely  repre-    KO_     To  stu(ients  we  unhesitatingly  recommend  it  as 
sents    he  present  state  of  gynaecology  ;  none  so  full     the  best  text.book  on  diseases  of  females  extant.-*?, 
of  well-digested  and  reliable  teaching  :  none  which     Lnnif.  M(lfl   Reporter,  June,  1869. 
bespeaks  an  author  more  apt  in  research  and  abun- 
dant in  resources.— N    Y  Med    Record   Mav  1    1872          Of  all  the  army  of  books  that  have  appeared  of  late 

,vr      ,       ,,          ,  '     years,  oil  the  disea-es  of  the  uterus  and  its  appendages, 

We  should  not  be  doing  our  duty  to  the  profession  ^e  kn'ow  of  noue  that  is  8O  clear?  compreheusive,  alld 
did  we  not  tell  those  who  are  unacquainted  with  the  practioal  as  this  of  Dr.  Thomas',  or  one  that  we  should 

ook    how  much  it  is  valued  by  gynaecologists,  and  e       .mticallv  recommend  to  the  young  pracri- 

how  it  is  m  many  respects  one  of  the  best  text-books      {  *^   gaids.-California  Med.  Gazette,  June, 

on  the  subject  we  possess  in  our  language      We  have     ,S69 
no  hesitation  in  recommeuding  Dr.  Thomas's  work  as 

one  of  the  most  complete  of  its  kind  ever  published  If  not  lhe  be'st  work  extant  on  tn«  subject  of  which 
It  should  be  in  the  possession  of  every  practitioner  if  treats-  u  is  certainly  second  to  none  other.  80 
for  reference  and  for  study. -London  Lancet,  April  short  a  time  has  elapsed  since  the  medical  press 
27,  1872.  '  teemed  with  commendatory  notices  of  the  first  edition, 

that  it  would  be  superfluous  to  give  an  extended  re- 

Onr  author  IB  not  one  of  those  whose  views"never     viewofwhat  is  now  firmly  established  as  Me  American 
change.       On  the  contrary,  they  have  been  modified     text-book  of  Gynaecology.—  N.  T.  Med.  Gazette,  July 
in  many  particulars  to  accord  with  the  progress  made     ^   jggg 
in  this  department  of  medical  science:  hence  it  has  the  ; 

freshness  of  an  entirely  new  work.  No  general  prac-  This  is  a  new  and  revised  edition  of  a  work  which 
ticioner  can  afford  to  be  without  it.— Si.  Louis  Med.  !  we  recently  noticed  at  some  length,  and  earnestly 
and  Sura  Journal  Mav  1872  commended  to  the  favorable  attention  of  our  readers. 

The  fact  that,  in  the  short  space  of  one  year,  this 

Its  able  author  need  not  fear  comparison  between     gecond  editioa  makes  its  appearance,  shows  that  the 
it  and  any  similar  work  in  the  English   language  ;     general  judgment  of  the  profession  has  largely  con- 
nay  more,  as  a  text  book  tor  students  and  as  a  guide     firmed  the  opinion  we  gave  at  that  time.— CincfonoW 
f»r  practitioners,  we  believe  it  is  unequalled.     In  the     Lancet   Aug  1869 
libraries  of  reading   physicians   we  meet   with   it  . 

of  ener  than  any  other  treatise  on  diseases  of  women,  i  It  is  so  short  a  time  since  we  gave  a  full  review  of 
We<  onclude  our  brief  review  by  repeatingthe  heany  i  the  first  edition  of  this  book,  that  we  deem  it  only 
cr>minenda»ion  of  tMs  volume  given  when  we  com-  necessary  now  to  call  attention  to  the  second  appear- 
meuced  :  if  either  student  or  practitioner  "an  get  but  ance  of  the  work.  Its  success  has  been  remarkable, 
one  book  on  diseases  of  women  that  hook  should  be  and  we  can  only  congratulate  the  author  on  the 
"Thomas."  —  Amer.  Jour.  Med.  Sciences,  April,  brilliant  reception  his  book  has  received. — N.  Y.  Med. 
1872.  i  Journal,  April,  1869. 


HENRY  C.  LEA'S  PUBLICATIONS— (Diseases  of  Women).  *3 

fTODGE  (HUGH  L.},  M.D., 

Emeritus  Professor  of  Obstetrics,  &c.,  in  the  University  of  Pennsylvania. 

ON  DISEASES  PECULIAR  TO  WOMEN;  including  Displacements 

of  the  Uterus.     With  original  illustrations.     Second  edition,  revised  and  enlarged.     In 
one  beautifully  printed  octavo  volume  of  531  pages,  extra  cloth.     $4  50.     (Lately  Issued.) 

From  PROP.  W.  H.  BYFORD,  of  the  Rush  Medical 
College,  Chico.go. 

The  book  bears  the  impress  of  a  master  hand,  and 


must,  as  its  predecessor,  prove  acceptable  to  the  pro- 
fession. la  diseases  of  women  Dr.  Hodge  has  estab- 
lished a.  school  of  treatment  that  has  become  world- 
wide in  fame. 

Professor  Hodge's  work  is  truly  an  original  one 
from  beginning  to  end,  consequently  no  one  can  pe- 
ruse its  pages  without  learning  something  new.  The 
book,  which  is  by  no  means  a.  large  one,  is  divided  into 
two  grand  sections,  so  to  speak  :  first,  that  treating  of 


pe 
f  th 


the  nervous  sympathies  of  the  uterus,  aud,  secondly, 


•hat  which  speaks  of  the  mechanical  treatment  of  dis- 
placements of  that  organ.  He  is  disposed,  as  a  non- 
Believer  in  the  frequency  of  inflammations  of  the 
uterus,  to  take  strong  ground  against  many  of  the 
highest  authorities  in  this  branch  of  medicine,  and 
the  arguments  which  he  offers  in  support  of  his  posi- 
tion are,  to  say  the  least,  well  put.  Numerous  wood- 
cuts adorn  this  portion  of  the  work,  and  add  incalcu- 
lably to  the  proper  appreciation  of  the  variously 
shaped  instruments  referred  to  by  our  author.  As  a 
contribution  to  the  study  of  women's  diseases,  it  is  of 
great  value,  and  is  abundantly  able  to  stand  on  its 
own  merits.— N.  Y.  Medical  Record,  Sept.  15,  1868. 


WEST  (CHARLES),  M.D. 

LECTURES  ON  THE  DISEASES  OF  WOMEN.    Third  American, 

from  the  Third  London  edition.     In  one  neat  octavo  volume  of  about  550  pages,  extra 
cloth,    $3  75  ;  leather,  $4  75. 
As  a  writer,  Dr.  West  stands,  in  our  opinion,  se-   seeking  truth,  and  one  that  will  convince  the  student 


cond  only  to  Watson,  the  "Macaulay  of  Medicine;' 
he  possesses  that  happy  faculty  of  clothing  instruc 
tion  in  easy  garments;  combining  pleasure  with 
profit,  he  leads  his  pupils,  in  spite  of  the  ancient  pro- 
verb, along  a  royal  road  to  learning.  His  work  is  one 
which  will  not  satisfy  the  extreme  on  either  side,  but 
it  is  one  that  will  please  the  great  majority  who  arc 


that  he  has  committed  himself  to  a  candid,  safe,  aad 
valuable  guide. — N.  A.  Med.-Chirurg  Review. 

We  have  to  say  of  it,  briefly  and  decidedly,  that  it 
is  the  best  work  on  the  subject  in  any  language,  and 
that  it  stamps  Dr.  West  as  the  facile  princeps  of 
British  obstetric  authors.—  Edinburgh  Med.  Journal. 


f>ARNES  (ROBERT],  M.  D.,  F.  R.  C.P., 

•*-*  Obstetric  Physician  to  St.  Thomas's  Hospital,  &-c. 

A  CLINICAL  EXPOSITION  OF  THE  MEDICAL  AND  SURGI- 
CAL DISEASES  OF  WOMEN.  In  one  handsome  octavo  volume  of  about  800  pages,  with 
169  illustrations.  Cloth.  $5  00;  leather,  $6  00.  (Just  Ready.^ 

The  very  complete  scope  of  this  volume  and  the  manner  in  which  it  has  been  filled  out,  may 
be  seen  by  the  subjoined  Summary  of  Contents. 

INTRODUCTION.  CHAPTER  I.  Ovaries  ;  Corpus  Luteum.  II.  Fallopian  Tubes.  III.  Shape  of 
Uterine  Cavity.  IV.  Structure  of  Uterus.  V.  The  Vagina.  VI.  Examinations  and  Diagnosis. 
VII.  Significance  of  Leucorrhoea.  VIII.  Discharges  of  Air.  IX.  Watery  Discharges.  X.  Puru- 
lent Discharges.  XI.  Hemorrh.igic  Discharges.  XII  Significance  of  Pain.  XIII.  Significance 
of  Dyspareunia.  XIV.  Significance  of  Sterility.  XV.  Instrumental  Diagnosis  and  Treatment. 
XVI.  Diagnosis  by  the  Touch,  the  Sound,  the' Speculum.  XVII.  Menstruation  and  its  Disor- 
ders. XVIII.  Amenorrhoea.  XIX.  Atnenorrhoea  (continued).  XX.  Dystnenorrhoaa.  XXI. 
Ovarian  Dysmenorrhoea,  &c.  XXII.  Inflammatory  Dysmenorrhoea.  XXIII  Irregularities  of 
Change  of  Life.  XXIV.  Relations  between  Menstruation  and  Diseases.  XXV.  Disorders  of  Old 
Age.  XXVI.  Ovary,  Absence  and  Hernia  of.  XXVII.  Ovary,  Hemorrhage,  &c.,  of.  XXVIII. 
Ovary,  Tubercle.  Cancer,  Ac.,  of.  XXIX.  Ovarian  Cystic  Tumors.  XXX.  Dermoid  Cysts  of 
Ovary.  XXXI.  Ovarian  Tumors,  Prognosis  of.  XXXII.  Diagnosis  of  Ovarian  Tumors.  XXXIII. 
Ovarian  Cysts,  Treatment  of.  XXXIV.  Fallopian  Tubes.  Diseases  of.  XXXV.  Broad  Liga- 
ments, Diseases  of.  XXXVI.  Extra-uterine  Gestation.  XXXVII.  Special  Pathology  of  Ute- 
rus. XXXVIII  General  Uterine  Pathology.  XXXIX  Alterations  of  Blood  Supply.  XL. 
Metritis,  Endometritis,  Ac.  XLI.  Pelvic  Cellulitis  and  Peritonitis,  Ac.  XLII  Haematocele,  &c. 
XLIII.  Displacements  of  Uterus.  XLIV.  Displacements  (continued).  XLV.  Retroversion  and 
Retroflexion.  XLVI.  Inversion.  XLVII.  Uterine  Tumors.  XLVIII.  Polypus  Uteri.  XLIX. 
Polypus  Uteri  (continued).  L.  Cancer.  LI.  Diseases  of  Vagina.  LII.  Diseases  of  the  Vulva. 


Embodying  the  long  experience  and  personal  obser- 
vation of  one  of  the  greatest  of  living  teachers  in  dis- 
eases of  women,  it  seems  pervaded  by  the  presence 
of  the  author,  who  speaks  directly  to  the  reader,  and 
speaks,  too,  as  one  having  authority.  And  yet,  not- 
withstanding this  distinct  personality,  there  is  noth- 
ing narrow  as  to  time,  place,  or  individuals,  in  the 
views  presented,  and  in  the  instructions  given  ;  Dr. 
Barnes  has  been  au  attentive  student,  not  only  of  Eu- 
ropean, but  also  of  American  literature,  pertaining  to 
diseases  of  females,  and  enriched  his  own  experience 
by  treasures  thence  gathered  ;  he  seems  as  familiar, 
for  example,  with  the  writings  of  Sims,  Ernmet,  Tho- 


mas, and  Peaslee.  as  if  these  eminent  men  were  his 
countrymen  and  colleagues,  and  gives  them  a  credit 
which  must  be  gratifying  to  every  American  physi- 
cian.— Am  Journ.  Med.  Sci .,  April,  1874. 

Throughout  the  whole  book  it  is  impossible  not  to 
feel  that  the  author  has  spontaneously,  conscientious- 
ly, and  fearlessly  performed  his  task.  He  goes  direct 
to  the  point,  and  does  not  loiter  on  the  way  to  gossip 
or  <iuarrel  with  other  authors.  Dr.  Barnes's  book 
will  be  eagerly  rend  all  over  the  world,  and  will 
everywhere  be  admired  for  its  comprehensiveness, 
honesty  of  purpose,  and  ability  — The  Onstet.  Journ. 
of  Great  Briia.in  and  Ireland,  March,  1874. 


CHURCHILL  ON  THE  PUERPERAL  FEVER  AND 
OTHER  DISEASES  PECULIAR  TO  WOMEN.  1  vol. 
8vo.,  pp.  450,  extra  cloth.  $2  50. 

DEWEES'S  TREATISE  ON  THE  DISEASES  OF  FE- 
MALES. With  illustrations.  Eleventh  Edition 
with  the  Author's  last  improvements- and  correc 
lions.  In  one  octavo  volume  of  636  i>ages,  with 
plates,  extra  cloth.  *3  00. 

WEST'S  ENQUIRY  INTO  THE  PATHOLOGICAL 
IMPORTANCE  OF  ULCEKATION  OF  THE  OS 
DTEIII.  1  vol.  Svo.,  extra  cloth.  $1  25. 


MEFGS  ON  WOMAN:  HER  DISEASES  AND  THEIR 
REMEDIES  A  Series  of  Lectures  to  his  Class. 
Fourth  and  Improved  Edition.  1  vol.  Svo.,  over 
700  pages,  extra  cloth,  *5  00  ;  leather,  +6  00. 

MEIGS  ON  THE  NATURE,  SIGNS,  AND  TREAT- 
MENT OF  CHILDBED  FEVER.  1  vol.  Svo.,  pp. 
365,  extra  cloth.  *2  00. 

ASHWELL'S  PRACTICAL  TREATISE  ON  THE  DIS- 
EASES PECULIAR  TO  WOMEN.  Third  American, 
from  the  Third  and  revised  London  edition.  1  vol. 
8vo.,  pp.  528,  extra  cloth.  $3  50. 


24 


HENRY  C.  LEA'S  PUBLICATIONS — (Midwifery). 


ffODGE  (HUGH  L.},  M.  Z>., 

•*••*•  Emeritus  Professor  of  Midwifery,  &c.,  in  the  University  of  Pennsylvania,  &c. 

THE  PRINCIPLES  AND  PRACTICE  OF  OBSTETRICS.  Illus- 
trated with  large  lithographic  plates  containing  one  hundred  and  fifty-nine  figures  from 
original  photographs,  and  with  numerous  wood-cuts.  In  one  large  and  beautifully  printed 
quarto  volume  of  550  double-columned  pages,  strongly  bound  in  extra  cloth,  $14. 


We  have  examined  Professor  Hodge's  work  with 
;reat  satisfaction ;  every  topic  is  elaborated  most 
ully.  The  views  of  the  author  are  comprehensive, 

ordinary  treatise  on  midwifery;  it  is,  in  fact,  a  cyclo-iand  concisely  stated.     The  rules  of  practice  are  jndi- 
psedia  of  midwifery.     He  has  aimed  to  embody  in  a  Icious,  and  will  enable  the  practitioner  to  meet  every 


The  work  of  Dr.  Hodge  is  something  more  than 
simple  presentation  of  his  particular  views  in  the  de- 
partment of  Obstetrics;  it  is  something  more  than  an 


single  volume  the  whole  science  and  art  of  Obstetrics. 
An  elaborate  text  is  combined  with  accurate  and  va- 
ried pictorial  illustrations,  so  that  no  fact  or  principle 
Is  left  unstated  or  unexplained.—  Am.  Med.  Times, 
Sept.  3,  1864. 

We  should  like  to  analyze  the  remainder  of  this 
excellent  work,  but  already  has  this  review  extended 
beyond  our  limited  space.  We  cannot  conclude  this 
BOtice  without  referring  to  the  excellent  finish  of  the 
work.  In  typography  it  is  not  to  be  excelled ;  the 
paper  is  superior  to  what  is  usually  afforded  by  our 
American  cousins,  quite  equal  to  the  best  of  English 


emergency  of  obstetric  complication  with  confidence. 
—Chicago  Med.  Journal,  Aug.  1864. 

More  time  than  we  have  had  at  our  disposal  since 
we  received  the  great  work  of  Dr.  Hodge  is  necessary 
to  do  it  justice.  It  is  undoubtedly  by  far  the  most 
original,  complete,  and  carefully  composed  treatise 
on  the  principles  and  practice  of  Obstetrics  which  has 
ever  been  issued  from  the  American  press. — Pacific 
Med.  and  Surg.  Journal,  July,  1864. 

We  have  read  Dr.  Hodge's  book  with  great  plea- 
sure, and  have  much  satisfaction  in  expressing  our 


books.      The  engravings  and   lithographs   are  most !  commendation  of  it  as  a  whole.    It  is  certainly  highly 
beautifully  executed.     The  work  recommends  itself  - 


for  its  originality,  and  is  in  every  way  a  most  valu- 
able addition  to  those  on  the  subject  of  obstetrics. — 
Canada  Med.  Journal,  Oct.  1864. 


instructive,  and  in  the  main,  we  believe,  correct.  The 
great  attention  which  the  author  has  devoted  to  the 
mechanism  of  parturition,  taken  along  with  the  con- 
clusions at  which  he  has  arrived,  point,  we  think, 


It  is  very  large,  profusely  and  elegantly  illustrated,  conclusively  to  the  fact  that,  in  Britain' at  least,  the 
and  is  fitted  to  take  its  place  near  the  works  of  great ;  doctrines  of  Naegele  have  been  too  blindly  received. 


obstetricians.    Of  the  American  works  on  the  subject 


)t  gr 
subi 


— Glasgow  Med.  Journal,  Oct.  1864. 


It  is  decidedly  the  best.—  Edinb.  Med.  Jour.,  Dec.  '64. 

#*#  Specimens  of  the  plates  and  letter-press  will  be  forwarded  to  any  address,  free  by  mail, 
en  receipt  of  six  cents  in  postage  stamps. 

BANNER  (THOMAS  H.),  M.  D. 

ON  THE  SIGNS  AND  DISEASES  OF  PREGNANCY.     First  American 

from  the  Second  and  Enlarged  English  Edition.     With  four  colored  plates  and  illustrations 
on  wood.     In  one  handsome  octavo  volume  of  about  500  pages,  extra  cloth,  $4  25. 
The  very  thorough  revisiom  the  work  has  undergone 
has  added  greatly  to  its  practical  value,  and  increased 


its  pr* 

materially  its  efficiency  as  a  guide  to  the  student  and 
to  the  young  practitioner. — Am.  Journ.  Med.  Sci., 
April,  1868. 

With  the  immense  variety  of  subjects  treated  of 
and  the  ground  which  they  are  made  to  cover,  the  im- 
possibility of  giving  an  extended  review  of  this  truly 
remarkable  work  must  be  apparent.  We  have  not  a 
single  fault  to  find  with  it,  and  most  heartily  com- 
mend it  to  the  careful  study  of  every  physician  who 
would  not  only  always  be  sure  of  his  diagnosis  of 


pregnancy,  but  always  ready  to  treat  all  the  nume- 
rous ailments  that  are,  unfortunately  for  the  civilized 
^omen  of  to-day,  so  commonly  associated  with  the 


function.—^,  y.  Med.  Record,  March  16  1868. 

We  recommend  obstetrical  students,  young  and 
old,  to  hav*  this  volume  in  their  collections.  It  con 
tains  not  onlj  a  fair  statement  of  the  signs,  symptoms, 
and  diseasef'of  pregnancy,  but  comprises  in  addition 
much  interesting  relative  matter  that  is  not  to  be 
found  in  anj  other  work  that  we  can  name.  —  Edin- 
burgh, Med  Journal,  Jan.  1868. 


&W4YNE  (JOSEPH  GRIFFITHS],  M.  D., 

*-3  Physician-Accoucheur  to  the  British  General  Hospital,  <fre. 

OBSTETRIC  APHORISMS  FOR  THE  USE  OF  STUDENTS  COM- 
MENCING MIDWIFERY  PRACTICE.  Second  American,  from  the  Fifth  and  Revised 
London  Edition,  with  Additions  by  E.  R.  HUTCHINS,  M.  D.  With  Illustrations.  In  one 
neat  12mo.  volume.  Extra  cloth,  $1  25.  (Now  Ready.) 

#.**•  See  p.  3  of  this  Catalogue  for  the  terms  on  which  this  work  is  offered  as  a  premium  to 
subscribers  to  the  "AMERICAN  JOURNAL  OP  THE  MEDICAL  SCIENCES." 

It  is  really  a  capital  little  compendium  of  the  sub-  answers  the  purpose.  It  is  not  only  valuable  for 
ject,  and  we  recommend  young  practitioners  to  buy  it  young  beginners,  but  no  one  who  is  not  a  proficient 
and  carry  it  with  them  when  called  to  attend  cases  of  j  in  the  art  of  obstetrics  should  be  without  it,  because 


labor.  They  can  while  away  the  otherwise  tedious 
hours  of  waiting,  and  thoroughly  fix  in  their  memo- 
ries the  most  important  practical  suggestions  it  con- 
tains. The  American  editor  has  materially  added  by 
his  notes  and  the  concluding  chapters  to  the  com- 
pleteness and  general  value  of  the  book. — Chicago 
Med.  Journal,  Feb.  1870. 

The  manual  before  us  contains  in  exceedingly  small 
compass — small  enough  to  carry  in  the  pockei — about 
all  there  is  of  obstetrics,  condensed  into  a  nutshell  of 
Aphorisms.  The  illustrations  are  well  selected,  and 

serve  as  excellent  reminders  of  the  conduct  of  labor-  I  when  he        ht  io  seucf  for  assistance.-^.  ¥.  Medial 
regular  and  difficult. — Cincinnati  Lancet,  April,   70.    Journal  May   1870 

Tbi«  is  a  tnostadmirable little  work,  and  completely  ' 


it  condenses  all  that  is  necessary  to  know  for  ordi 
nary  midwifery  practice.  We  commend  the  book 
most  favorably.— Stf.  Louis  Med.  and  Surg.  Journal, 
Sept.  10,  1870. 

A  studied  perusal  of  this  little  book  has  satisfied 
us  of  its  eminently  practical  value.  The  object  of  the 
work,  the  author  says,  in  his  preface,  is  to  give  the 
student  a  few  brief  and  practical  directions  respect- 
ing the  management  of  ordinary  cases  of  labor  ;  and 
also  to  point  out  to  him  in  extraordinary  cases  when 
and  how  he  may  act  upon  his  own  responsibility,  and 


\riNCKEL  (F.}, 

Professor  and  Director  of  the  Gynaecological  Clinic  in  the  University  of  Rostock. 

A  COMPLETE  TREATISE  ON  THE  PATHOLOGY  AND  TREAT- 
MENT OF  CHILDBED,  for  Students  and  Practitioners.  Translated,  with  the  consent  of 
the  author,  from  the  Second  German  Edition,  by  JAMES  READ  CHADWICK,  M  D.  In  one 
octavo  volume.  (Preparing.) 


HENRY  C.  LEA'S  PUBLICATIONS — (Midwifery). 


J  EISHMAN 

Regius  Profe. 


WILLIAM],  M.D., 

r  of  Midwifery  in  the  University  of  Glasgow,  Ac. 

SYSTEM  OF  MIDWIFERY,  INCLUDING  THE  DISEASES  OF 

PREGNANCY  AND  THE  PUERPERAL  STATE.  In  one  large  and  very  handsome  oc- 
tavo volume  of  over  700  pages,  with  one  hundred  and  eighty-two  illustrations.  Cloth, 
$5  00  ;  leather,  $6  00.  (Now  Ready.) 


This  is  one  of  a  most  complete  and  exhaustive  cha- 
racter. We  have  gone  carefully  through  it,  and  there 
is  no  suhject  in  Obstetrics  which  has  not  heen  con- 
sidered well  and  fully.  The  result  is  a  work,  not 
only  admirable  as  a  text-book,  but  valuable  as  a  work 
of  reference  to  the  practitioner  in  the  various  emer- 
gencies of  obstetric  practice.  Take  it  all  in  all,  we 
have  no  heMtatiou  in  saying  that  it  is  in  our  judgment 
the  best  English  work  011  the  subject. — London Lcin- 
crf.Ang.  23,  1873. 

The  work  of  Leishman  gives  an  excellent  view  of 
modern  midwifery,  and  evinces  itsauihor'sextensive 
acquaintance  with  British  and-foreign  literature  ;  and 
not  only  acquaintance  with  it,  but  wholesome  diges- 
tion and  sound  judgment  of  it.  He  has,  withal,  a 
manly,  free  style,  and  can  state  a  difficult  and  compli- 
cated matter  with  remarkable  clearness  and  brevity. 
—Bdin.  Med.  Journ.,  Sept.  1873. 

The  author  has  succeeded  in  presenting  to  the  pro- 
fession an  admirable  treatise,  especially  in  its  practi- 
cal aspects  ;  one  which  is,  in  general,  clearly  written, 
a.nd  sound  in  doctrine,  and  one  which  cannot  fail  to 
add  to  his  already  high  reputation.  In  concluding 
our  examination  of  this  work,  we  cannot  avoid  again 
saying  that  Dr.  Leishman  has  fully  accomplished 
that  difficult  task  of  presenting  a  good  text-book  upon 
obstetrics.  We  know  none  better  for  the  nse  of  the  stu- 
dent or  junior  practitioner. — Am.  Practitioner,  Mar. 
187-1. 

It  proposes  to  offer  to  practitioners  and  students 


"A  Complete  System  of  the  Midwifery  of  the  Present 
Day,"  and  well  redeems  the  promise.  In  all  that 
relates  to  the  subject  of  labor,  the  teaching  is  admi- 
rably clear,  concise,  and  practical,  representing  not 
alone  British  practice,  but  the  contributions  of  Con- 
tinental and  American  schools. — N.  ¥.  Med.  Record, 
March  2,  Is74. 

The  work  of  Dr.  Leishman  is,  in  many  respects, 
not  only  the  best  treatise  on  midwifery  that  we  IIK  ve 
seen,  but  one  of  the  best  treatises  on  any  medical  sub- 
ject that  has  been  published  of  late  years.— Lund. 
Practitioner,  Feb.  1874. 

It  was  written  to  supply  a  desideratum,  and  we  will 
be  much  surprised  if  it  does  not  fulfil  the  purpose  of 
its  author.  Taking  it  as  a  whole,  we  know  of  no 
work  on  obstetrics  by  an  English  author  in  which  the 
student  and  the  practitioner  will  find  the  information 
so  clear  and  so  completely  abieast  of  the  present  state 
of  our  knowledge  on  the  subject. —  Glasgow  Mtd. 
Journ.,  Aug.  1873. 

Dr.  Leishman's  System  of  Midwifery,  which  has 
only  just  been  published,  will  go  far  to  supply  the 
want  which  has  so  long  been  felt,  of  a  really  good 
modern  English  text-book.  Although  large,  as  is  in- 
evitable in  a  work  on  so  extensive  a  subject,  it  is  so 
well  aud  clearly  written,  that  it  is  never  wearisome 
to  read.  Dr.  Leishman's  work  may  be  confidently 
recommended  as  an  admirable  text-book,  and  is  sure 
to  be  largely  used.— Lond.  Mad.  Record,  Sept.  1873. 


ftAMSBOTHAM  (FRANCIS  H.),  M.D. 

THE  PRINCIPLES  AND  PRACTICE  OF  OBSTETRIC  MEDI- 
CINE AND  SURGERY,  in  reference  to  the  Process  of  Parturition.  A  new  and  enlarged 
edition,  thoroughly  revised  by  the  author.  With  additipns  by  W.  V.  KEATING,  M.  D., 
Professor  of  Obstetrics,  &c.,  in  the  Jefferson  Medical  College,  Philadelphia.  In  one  large 
and  handsome  imperial  octavo  volume  of  650  pages,  strongly  bound  in  leather,  with  raised 
bands  ;  with  sixty-four  beautiful  plates,  and  numerous  wood-cuts  in  the  text,  containing  in 
all  nearly  200  large  and  beautiful  figures.  $7  00. 
We  will  only  add  that  the  student  will  learn  from 

it  all  he  need  to  know,  and  the  practitioner  will  find 

It,  as  a  book  of  reference,  surpassed  by  none  other.— 

Stethoscope. 
The  character  and  merits  of  Dr.  Ramsbotham's 

work  are  so  well  known  and  thoroughly  established, 

that  comment  is  unnecessary  and  praise  superfluous. 

The  illustrations,  which  are  numerous  and  accurate, 

are  executed  in  the  highest  style  of  art.     We  cannot 

too  highly  recommend  the  work  to  our  readers.— fitf. 

Louis  Med.  and  Surg.  Journal. 


To  the  physician's  library  it  is  indispensable,  while 
to  the  student,  as  a  text-book,  from  which  to  extract 
the  material  for  laying  the  foundation  of  an  education 
on  obstetrical  science,  it  has  no  superior. — Ohio  Med. 
and  Surg.  Journal. 

When  we  call  to  mind  the  toil  we  underwent  in 
acquiring  a  knowledge  of  this  subject,  we  cannot  but 
envy  the  student  of  the  present  day  the  aid  which 
this  work  will  afford  him.—  Am.  Jour,  of  the  Med. 
Sciences. 


S7HURCHILL  (FLEETWOOD),  M.D.,  M.R.I.A. 

ON  THE  THEORY  AND  PRACTICE  OF  MIDWIFERY.    A  new 

American  from  the  fourth  revised  and  enlarged  London  edition.  With  notes  and  additions 
by  D  FRANCIS  CONDIE,  M.  D.,  author  of  a  "Practical  Treatise  on  the  Diseases  of  Chil- 
dren ' '  &c.  With  one  hundred  and  ninety-four  illustrations.  In  one  very  handsome  octavo 
volume  of  nearly  700  large  pages.  Extra  cloth,  $4  00 ;  leather,  $5  00. 

Thes,  additions  render  the  work  still  more  com-  |  quainted  can  compare  favorably  with   this    ir  re- 
Dlete  and  acceptable  than  ever;    and  we  can  com-  j  spect  to  the  amount  of  material  whu^has  beer  gath- 

pieio  o,uu    t*v       r  „__„*    /.rvf^ialitv  anil 


pee  an     ace 

mend  it  to  the  profession  with  great  cordiality  and 

pleasure.— Gin  linnati  Lancet. 

Few  work?  on  this  branch  of  medical  science  ar» 
equal  to  it,  certainly  none  excel  it,  whether  in  regard 
to  theory  or  practice—  Brit.  Am.  Journal. 

No  treatise  on  obstetrics  with  which  we  are  ac- 


ered from  every  source.—  Boston  Med.  and  Surg. 
Journa  . 

There  is  no  better  text-book  for  students,  or  work 
of  reference  and  study  for  the  practising  physician 
than  this.  It  should  adorn  and  enrich  every  medical 
library. — Chicago  Med.  Journal. 


MONTGOMERY'S  EXPOSITION  OF  THE  SIGNS, 
AND  SYMPTOMS  OF  PREGNANCY.  With  two  i 
exquisite  colored  plates,  and  numerous  wood  cuts.  , 
In  1  vol.  8vo.,  of  nearly  600  pp  ,  extra  cloth.  $3  ,o.  j 

BltfBY'S  SYSTEM  OF  MIDWIFERY.  With  Notes' 
and  Additional  Illustrations.  Second  American 


One  volume  octavo,  extra  cloth,  422  pages 
«250. 

DEWEES'S  COMPREHENSIVE  SYSTEM  OP  MID- 
WIFERY.  Twelfth  edition,  with  the  author's  la* t 
improvements  and  corrections.  In  one  octavo  vol- 
ume, extra  cloth,  of  600  pages.  $3  60. 


26 


HENRY  C.  LEA'S  PUBLICATIONS — (Surgery). 


S1ROSS  (SAMUEL  D.},  M.D., 

>>^"  Professor  of  Surgery  in  the  Jefferson  Medical  College  of  Philadelphia. 

A  SYSTEM  OF  SURGERY:    Pathological,  Diagnostic,  Therapeutic, 

and  Operative.     Illustrated  by  upwards  of  Fourteen  Hundred  Engravings.     Fifth  edition, 
carefully  revised,  and  improved.     In  two  large  and  beautifully  printed  imperial  octavo  vol- 
umes of  about  2300  pages,  strongly  bound  in  leather,  with  raised  bands,  $15.    (Just  Ready.) 
The  continued  favor,  shown  by  the  exhaustion  of  successive  large  editions  of  this  great  work, 
proves  that  it  has  successfully  supplied  a  want  felt  by  American  practitioners  and  students.    In  the 
present  revision  no  pains  have  been  spared  by  the  author  to  bring  it  in  every  respect  fully  up  to 
the  day.     To  effect  this  a  large  part  of  the  work  has  been  rewritten,  and  the  whole  enlarged  by 
nearly  one- fourth,  notwithstanding  which  the   price  has  been  kept  at  its  former  very  moderate 
rate.     By  the  use  of  a  close,  though  very  legible  type,  an  unusually  large  amount  ol  matter  is 
condensed  in  its  pages,  the  two  volumes  containing  as  much  as  four  or  five  ordinary  octavos. 
This,  combined  with  the  most  careful  mechanical  execution,  and  its  very  durable  binding,  renders 
it  one  of  the  cheapest  works  accessible  to  the  profession.     Every  subject  properly  belonging  to  the 
domain  of  surgery  is  treated  in  detail,  so  that  the  student  who  possesses  this  work  may  be  said  to 
have  in  it  a  surgical  library. 


It  must  long  remain  the  most  comprehensive  work 
on  this  important  part  of  medicine. — Boston  Medical 
and  SurfficalJournal,  March  23,  1865. 

We  have  compared  it  with  most  of  our  standard 
works,  such  as  those  of  Erichsen,  Miller,  Feigusson, 
Byrne,  and  others,  and  we  must,  in  justice  to  our 
author,  award  it  the  pie-eminence.  As  a  work,  com- 
plete in  almost  every  detail,  no  matter  how  minute 
or  trifling,  and  embracing  every  subject  known  in 
the  principles  and  practice  of  surgery,  we  believe  it 
stands  without  a  rival.  Dr.  Gross,  in  his  preface,  re- 
marks "my  aim  has  been  to  embrace  the  whole  do- 
main of  surgery,  and  to  allot  to  every  subject  its 
legitimate  claim  to  notice;"  and,  we  assure  our 
readers,  he  has  kept  his  word.  It  is  a  work  which 
we  can  most  confidently  recommend  to  our  brethren, 
for  its  utility  is  becoming  the  more  evident  the  longer 
it  is  upon  the  shelves  of  our  library.— Canada  Med. 
Journal,  September,  1865. 

The  first  two  editions  of  Professor  Gross'  System  of 
Surgery  are  so  well  known  to  the  profession,  and  so 
highly  prized,  that  it  would  be  idle  for  us  to  speak  in 
praise  of  this  work. —  Chicago  Medical  Journal, 
September,  1865. 

We  gladly  indorse  the  favorable  recommendation 
of  the  work,  both  as  regards  matteV  and  style,  which 
we  made  when  noticing  its  first  appearance.— British 
and  Foreign  Medico-Chirurgical  Review,  Oct.  1865. 

The  most  complete  work  that  has  yet  issued  from 
the  press  on  the  science  and  practice  of  surgery. — 
London  Lancet. 

This  system  of  surgery  is,  we  predict,  destined  to 
take  a  commanding  position  in  our  surgical  litera- 
ture, and  be  the  crowning  glory  of  the  author's  well 
earned  fame.  As  an  authority  on  general  surgical 
subjects,  this  work  is  long  to  occupy  a  pre-eminent 
place,  not  only  at  home,  but  abroad.  We  have  no 


hesitation  in  pronouncing  it  without  a  rival  in  our 
language,  aud  equal  to  the  best  systems  ol  surgery  in 
any  language. — N.  Y.  Med.  Journal. 

Not  only  by  far  the  best  text-book  on  the  subject, 
AS  a  whole,  within  the  reach  of  American  students, 
but  one  which  will  be  much  more  than  ever  likely 
to  be  resorted  to  and  regarded  as  a  high  authority 
abroad. — Am.  Journal  Med.  Sciences,  Jan.  1S65. 

The  work  contains  everything,  minor  and  major, 
operative  and  diagnostic,  including  mensuration  and 
examination,  venereal  diseases,  and  uterine  manipu- 
lations and  operations.  It  is  a  complete  Thesaurus 
of  modern  surgery,  where  the  student  and  practi- 
tioner shall  not  seek  in  rain  for  what  they  desire.— 
San  Francisco  Med.  Press,  Jan.  1865. 

Open  it  where  we  may,  we  find  sound  practical  in- 
formation conveyed  in  plain  language.  This  book  is 
no  mere  provincial  or  even  national  system  of  sur- 
gery, but  a  work  which,  while  very  largely  indebted 
to  the  past,  has  a  strong  claim  on  the  gratitude  of  the 
future  of  surgical  science. — Edinburgh  Med.  Journal, 
Jan.  1865. 

A  glance  at  the  work  is  sufficient  to  show  that  the 
author  and  publisher  have  spared  no  labor  in  making 
it  the  most  complete  "System  of  Surgery"  ever  pub- 
lished in  any  country. — St.  Louis  Med.  and  Surg. 
Journal,  April,  1865. 

A  system  of  surgery  which  we  think  unrivalled  in 
our  language,  and  which  will  indelibly  associate  his 
name  with  surgical  science.  And  what,  in  our  opin- 
ion, enhances  the  value  of  the  wors  is  that,  while  the 
practising  surgeon  will  find  all  that  he  requires  in  it, 
it  is  at  the  same  time  one  of  the  most  valuable  trea- 
tises which  can  be  put  into  the  hands  of  the  student 
seeking  to  know  the  principles  and  practice  of  this 
branch  of  the  profession  which  he  designs  subse- 
quently to  follow. — The  Brit.  Am.Journ.,  Montreal. 


Y  THE  SAME  AUTHOR. 

A   PRACTICAL    TREATISE    ON    FOREIGN    BODIES   IN   THE 

AIR-PASSAGES.     In  1  vol.  8vo.  cloth,  with  illustrations,     pp.  468.     $2  75. 


8  :EY'S    OPERATIVE  SURGERY.     In  1   vol.   8vo.  \  GIBSON'S  INSTITUTES  AND  PRACTICE  OF  SUR- 


jloth,  of  over  650  pages  ;  with  about  100  wood-cuts. 
*3  25. 

COOPER'S  LECTURES  ON  THE  PRINCIPLES  AND 
PRACTICE  OF  SURGERY.  In  1  vol.  Svo.  cloth,  750  p.  #2. 


e»ERY.  Eighth  edition,  improved  and  altered.  With 
thirty-four  plates.  In  two  handsome  octavo  vel- 
uines,  about  1000  pp., leather, raised  bands.  $660. 


M 


1LLER  (JAMES), 

Late  Professor  of  Surgery  in  the  University  of  Edinburgh,  &c. 

PRINCIPLES  OF  SURGERY.     Fourth  American,  from  the  third  and 

revised  Edinburgh  edition.  In  one  large  and  very  beautiful  volume  of  700  pages,  with 
two  hundred  and  forty  illustrations  on  wo»d,  extra  cloth.  $3  75. 

TOY  THE  SAME  AUTHOR. 

THE   PRACTICE   OF   SURGERY.    Fourth  American,  from  the  last 

Edinburgh  edition.  Revised  by  the  American  editor.  Illustrated  by  three  hundred  and 
sixty-four  engravings  on  wood.  In  one  large  octavo  volume  of  nearly  700  pages,  extra 
cloth.  $3  75.  

VARGENT  (F.  W.),  M.D. 
°      OJN   BA^DAUIJSU  AND    OTHER   OPERATIONS   OF   MINOR 

SURGERY,  New  edition,  with  an  additional  chapter  on  Military  Surgery.  One  handsome 
royal  I2mo.  volume,  of  nearly  400  pages,  with  184  wood-cuts.  Extra  cloth,  $1  76. 


HENRY  C.  LEA'S  PUBLICATIONS— (Surgery). 


27 


J^SHHURST  (JOHN,  Jr.],  M.D., 

Surgeon  to  the  Episcopal  Hospital,  Philadelphia. 

THE    PRINCIPLES   AND    PRACTICE   OF    SURGERY.     In  one 

very  large  and  handsome  octavo  volume  of  about  1000  pages,  with  nearly  550  illustrations 
extra  cloth,  $6  50;  leather,  raised  bands,  $7  50.      (Just  Issued.) 

The  object  of  the  author  has  been  to  present,  within  as  condensed  a  compass  as  possible,  a 
complete  treatise  on  Surgery  in  all  its  branches,  suitable  both  as  a  text-book  for  the  student  and 
a  work  of  reference  for  the  practitioner.  So  much  has  of  late  years  been  done  for  the  advance- 
ment of  Surgical  Art  and  Science,  that  there  seemed  to  be  a  want  of  a  work  which  should  present 
the  latest  aspects  of  every  subject,  and  which,  by  its  American  character,  should  render  accessible 
to  the  profession  at  large  the  experience  of  the  practitioners  of  both  hemispheres.  This  has  been 
the  aim  of  the  author,  and  it  is  hoped  that  the  volume  will  be  found  to  fulfil  its  purpose  satisfac- 
torily. The  plan  and  general  outline  of  the  work  will  be  seen  by  the  annexed 

CONDENSED  SUMMARY  OF  CONTENTS. 

CHAPTER  I.  Inflammation.  II.  Treatment  of  Inflammation.  III.  Operations  in  general: 
Anesthetics.  IV.  Minor  Surgery.  V.  Amputations.  VI.  Special  Amputations.  VII.  Effects 
of  Injuries  in  General  :  Wounds.  VIII.  Gunshot  Wounds.  IX.  Injuries  of  Bloodvessels.  X. 
Injuries  of  Nerves,  Muscles  and  Tendons,  Lymphatics,  Bursae,  Bones,  and  Joints.  XI.  Fractures. 
XII.  Special  Fractures.  XIII.  Dislocations.  XIV.  Effects  of  Heat  and  Cold.  XV.  Injuries 
of  the  Head.  XVI.  Injuries  of  the  Back.  XVII.  Injuries  of  the  Face  and  Neck.  XVIII. 
Injuries  of  the  Chest.  XIX.  Injuries  of  the  Abdomen  and  Pelvis.  XX.  Diseases  resulting  from 
Inflammation.  XXI.  Erysipelas.  XXII.  Pyaemia  XXIII.  Diathetic  Diseases:  Struma  (in- 
eluding  Tubercle  and  Scrofula);  Rickets.  XXIV.  Venereal  Diseases;  Gonorrhoea  and  Chancroid. 
XXV.  Venereal  Diseases  continued:  Syphilis.  XXVI.  Tumors.  XXVCI.  Surgical  Diseases  of 
Skin,  Areolar  Tissue,  Lymphatics,  Muscles,  Tendons,  and  Bursae.  XXVIII.  Surgical  Disease 
of  Nervous  System  (including  Tetanus).  XXIX.  Surgical  Diseases  of  Vascular  System  (includ- 
ing Aneurism).  XXX.  Diseases  of  Bone.  XXXI.  Diseases  of  Joints.  XXXII.  Excisions. 
XXXIII.  Orthopaedic  Surgery.  XXXIV.  Diseases  of  Head  and  Spine.  XXXV.  Diseases  of  the 
Eye.  XXXVI.  Diseases  of  the  Ear.  XXXVII.  Diseases  of  the  Face  and  Neck.  XXXVIII. 
Diseases  of  the  Mouth,  Jaws,  and  Throat.  XXXIX.  Diseases  of  the  Breast.  XL.  Hernia.  XLI. 
Special  Herniae.  XLII.  Diseases  of  Intestinal  Canal.  XLIII.  Diseases  of  Abdominal  Organs, 
and  various  operations  on  the  Abdomen.  XLIV.  Urinary  Calculus  XLV.  Diseases  of  Bladder 
and  Prostate.  XLVI.  Diseases  of  Urethra.  XLVII.  Diseases  of  Generative  Organs.  INDEX. 


Its  author  has  evidently  tested  the  writings  and 
experiences  of  the  past  arid  present  in  the  crucible 
of  a  careful,  analytic,  and  honorable  mind.  and  faith- 
fully endeavored  to  bring  his  work  up  to  the  level  of 
the  highest  standard  of  practical  surgery  He  is 
frank  and  definite,  and  gives  us  opinions,  and  gene- 
rally sound  ones,  instead  of  a  mere  resume  of  the 
opinions  of  others  He  isconservative.  but  not  hide- 
bound by  authority.  His  style  is  clear,  elegant,  and 
scholarly.  The  w*  rk  is  an  admirable  text  book,  and 
a  useful  book  of  reference  It  is  a  credit  to  American 
professional  literature,  and  one  of  the  first  ripe  fruits 
of  the  soil  fertilized  by  the  blood  of  our  late  unhappy 
war.—  N.  Y.  Mttd.  Record,  Feb.  1,  1S72. 


Indeed,  the  work  as  a  whole  must  be  regarded  aa 
an  excellent  and  concise  exponent  of  modern  sur- 
gery, and  as  such  it  will  be  found  a  valuable  text- 
book for  the  student,  and  a  useful  book  of  reference 
for  the  general  practitioner. — JV.  Y.  Mtd.  Journal, 
Feb.  1872. 

It  gives  us  great  pleasure  to  call  the  attention  of  the 
profession  to  this  excellent  work.  Our  knowledge  of 
its  talented  and  accomplished  author  led  us  to  expect 
from  him  a  very  valuable  treatise  upon  subjects  to 
which  he  has  repeatedly  given  evidence  of  having  pro- 
fitably devoted  much  time  and  labor,  aud  we  are  in  no 
way  disappointed.—  Phila.  Mtd.  Time*,  Feb.  1, 1872. 


3IRRIE  (  WILLIAM],  F.  R.  S.  E., 

Professor  of  Surgery  in  the  University  of  Aberdeen. 

THE  PRINCIPLES  AND  PRACTICE  OF  SURGERY.    Edited  by 

JOHN  NEILL,  M.  D.,  Professor  of  Surgery  in  the  Penna.  Medical  College,  Surgeon  to  the 
Pennsylvania  Hospital,  Ac.  In  one  very  handsome  octavo  volume  of  780  pages,  with  318 
illustrations,  extra  cloth.  $3  75. 


TJAMILTON  (FRANK  H.)t  M.D., 

Professor  of  Fracture*  and  Dislocation*,  Ac.,  in  Bellevue  Hosp.  Med.  College,  New  York. 

A  PRACTICAL  TREATISE  ON  FRACTURES  AND  DISLOCA- 
TIONS. Fourth  edition,  thoroughly  revised.  In  one  large  and  handsome  octavo  volume 
of  nearly  800  pages,  with  several  hundred  illustrations.  Extra  cloth,  $5  75  ;  leather,  $6  75. 
( Jttst  Issued. ) 


It  is  not,  of  course,  our  intention  to  review  in  ex- 
tenso,  Hamilton  on  "Fractures  and  Dislocations." 
Eleven  years  ago  such  review  might  not  have  been 
out  of  place ;  to-day  the  work  is  au  authority,  so  well, 
so  generally,  and  so  favorably  known,  that  it  only 
remains  for  the  reviewer  to  say  that  a  new  edition  is 
just  out,  and  it  is  better  than  either  of  its  predeces- 
sors.— Cincinnati  Clinic,  Oct.  14,  1S71. 

Undoubtedly  the  best  work  on  Fractures  and  Dis- 
locations in  the  English  language. — Cincinnati  Med. 
Repertory,  Oct.  1871. 

We  have  once  more  before  us  Dr.  Hamilton's  admi- 


rable treatise,  which  we  have  always  considered  the 
most  complete  and  reliable  work  on  the  t^ubject.  As 
a  whole,  the  work  is  without  an  equal  in  the  litera- 
ture of  the  profession. — Boston  Med.  and  Surg. 
Journ.,  Oct.  12,  1871. 

It  is  unnecessary  at  this  time  to  com  mend  the  book, 
except  to  such  as  are  beginners  in  the  study  of  this 
particular  branch  of  surgery.  Every  practical  sur- 
geon in  this  country  and  abroad  knows  of  it  as  a  most 
trustworthy  guide,  and  one  which  they,  in  common 
with  us,  would  unqualifiedly  recommend  as  the  high- 
e>t  authority  in  auy  language. — N.  Y.  Med.  Record, 
Oct.  16,  1871. 


HENRY  C.  LEA'S  PUBLICATIONS — (Surgery). 


CJRICHSEN  (JOHN  E.), 

•*-*  Professor  of  Surgery  in  University  College,  London,  etc. 

THE  SCIENCE  AND  ART  OF  SURGERY;  being  a  Treatise  on  Sur- 

gical  Injuries,  Diseases,  and  Operations.  Revised  by  the  author  from  the  Sixth  and 
enlarged  English  Edition.  Illustrated  by  over  seven  hundred  engravings  on  wood.  In 
two  large  and  beautiful  octavo  volumes  of  over  1700  pages,  extra  cloth,  $9  00  ;  leather, 
$11  00.  (Just  Ready.) 

Author'1  s  Preface  to  the  New  American  Edition. 

"  The  favorable  reception  with  which  the  '  Science  and  Art  of  Surgery'  has  been  honored  by  the 
Surgical  Profession  in  the  United  States  of  America  has  been  not  only  a  source  of  deep  gratifica- 
tion and  of  just  pride  to  me,  but  has  laid  the  foundation  of  many  professional  friendships  that 
are  amongst  the  agreeable  and  valued  recollections  of  my  life. 

"I  have  endeavored  to  make  the  present  edition  of  this  work  more  deserving  than  its  predecessors 
of  the  favor  that  has  been  accorded  to  them.     In  consequence  of  delays  that  have  unavoidably 
occurred  in  the  publication  of  the  Sixth  British  Edition,  time  has  been  afforded  to  me  to  add  to  this 
one  several  paragraphs  which  I  trust  will  be  found  to  increase  the  practical  value  of  the  work." 
LONDON,  Oct.  1872. 

On  no  former  edition  of  this  work  has  the  author  bestowed  more  pains  to  render  it  a  complete  and 
satisfactory  exposition  of  British  Surgery  in  its  modern  aspects.  Every  portion  has  been  sedu- 
lously revised,  and  a  large  number  of  new  illustrations  have  been  introduced.  In  addition  to  the 
material  thus  added  to  the  English  edition,  the  author  has  furnished  for  the  American  edition  such 
material  as  has  accumulated  since  the  passage  of  the  sheets  through  the  press  in  London,  so  that 
the  work  as  now  presented  to  the  American  profession,  contains  his  latest  views  .and  experience. 
The  increase  in  the  size  of  the  work  has  seemed  to  render  necessary  its  division  into  two  vol- 
umes. Great  care  has  been  exercised  in  its  typographical  execution,  and  it  is  confidently  pre- 
sented as  in  every  respect  worthy  to  maintain  the  high  reputation  which  has  rendered  it  a  stand- 
ard authority  on  this  department  of  medical  science. 

These  are  only  a  few  of  the  points  in  which  the  states  in  his  preface,  they  are  not  confined  to  any  one 
present  edition  of  Mr.  Erichsen's  work  surpasses  its  :  portion,  but  are  distributed  generally  through  the 
predecessors.  Throughout  there  is  evidence  of  a  j  subjects  of  which  the  work  treats.  Certainly  oue  of 
laborious  care  and  solicitude  in  seizing  the  passing  j  the  most  valuable  sections  of  the  book  seems  to  us  to 
knowledge  of  the  day,  which  reflects  the  greatest  be  that  which  treats  of  the  diseases  of  the  arteries 
credit  on  the  author,  and  much  enhances  the  value  i  and  the  operative  proceedings  which  they  necessitate. 
ofhiswork.  We  can  only  admire  the  industry  which  j  In  few  text-books  is  so  much  carefully  arranged  in- 
has  enabled  Mr.  Erichsen  thus  to  succeed,  amid  the  :  formation  collected.  —  London  Med.  Times  and  Gaz., 
distractions  of  active  practice,  in  producing  emphatic-  Oct.  26,  1872. 

ally  THE  book  of  reference  and  study  for  British  prac-        The  eDtire  WOrk,  complete,  as   the  great  English 
titioners  of  surgery.—  London  Lancet,  Oct.  26,  1872.     j  treatise  on  Surgery  of  our  own  time,  is,  we  can  assure 

Considerable  changes  have  been  made  in  this  edi-    our  readers,  equally  well  adapted  for  the  most  junior 
lion,  and  nearly  a  hundred  new  illustrations  have     student,  and,  as  a  book  of  reference,  for  the  advanced 
been  added.    It  is  difficult  in  a  small  compass  to  point  j  practitioner.  —  Dublin  Quarterly  Journal. 
out  the  alterations  and  additions  ;  for,  as  the  author  I 

riRUITT  (ROBERT],  M.R.C.S.,  frc. 

THE  PRINCIPLES  AND  PRACTICE  OF  MODERN  SURGERY. 

A  new  and  revised  American,  from  the  eighth  enlarged  and  improved  London  edition  Illus- 
trated with  four  hundred  and  thirty  -two  wood  engravings.  In  one  very  handsome  octavo 
volume,  of  nearly  700  large  and  closely  printed  pages.  Extra  cloth,  $4  00  ;  leather,  $5  00. 


All  that  the  surgical  student  or  practitioner  could 
desire. — Dublin  Quarterly  Journal. 

It  is  a  most  admirable  book.  We  do  not  know 
when  we  have  examined  one  with  more  pleasure. — 
Boston  Med.  and  Surg.  Journal. 

In  Mr.  Druitt's  book,  though  containing  only  some 
seven  hundred  pages,  both  the  principles  and  the 

(T.  J.]. 


practice  of  surgery  are  treated,  and  so  clearly  and 
perspicuously,  as  to  elucidate  every  important  topic. 
We  nave  examined  the  book  most  thoroughly,  and 
can  say  that  this  success  is  well  merited.  His  book, 
moreover,  possesses  the  inestimable  advantages  of 
having  the  subjects  perfectly  well  arranged  and  clas- 
sified, and  of  being  written  in  a  style  at  once  clear 
tnd  succinct.  —  Am.  Journal  of  Med.  Sciences. 


ON  THE   DISEASES,  INJURIES,  AND  MALFORMATIONS   OF 

THE  RECTUM  AND  ANUS;  with  remarks  on  Habitual  Constipation.  Second  American, 
from  the  fourth  and  enlarged  London  edition.  With  handsome  illustrations.  In  one  very 
beautifully  printed  octavo  volume  of  about  300  pages.  $3  25. 

T21GELO  W  (HENRY  J.),  M.  /)., 

•*-'  Professor  of  Surgery  in  the  Massachusetts  Ned.  College. 

ON   THE   MECHANISM   OF    DISLOCATION  AND  FRACTURE 

OP  THE  HIP.  With  the  Reduction  of  the  Dislocation  by  the  Flexion  Method.  With 
numerous  original  illustrations.  In  one  very  handsome  octavo  volume.  Cloth.  $2  50. 
(Lately  Issued.) 

TAWSON  (GEORGE],  F.  R.  C.  S.,  Engl., 

•J-^  Assistant  Surgeon  to  the  Royal  London  Ophthalmic  Hospital,  Moor  fields,  Ac. 

INJURIES  OF  THE  EYE,  ORBIT,  AND  EYELIDS :  their  Imme- 
diate and  Remote  Effects.  With  about  one  hundred  illustrations.  In  one  very  hand 
some  octavo  volume,  extra  cloth,  $3  50. 

It  is  an  admirable  practical  book  in  the  highest  and  best  sense  of  the  phrase. — London  Medical  Times 
and  Gazette,  May  18,  1867. 


HENRY  C.  LEA'S  PUBLIC ATioxa—f  Surgery). 


29 


T>RYANT  (THOMAS],  F.R.C.S., 

•U  Surgeon  to  Guy's  Hospital. 

THE  PRACTICE  OF  SURGERY.  With  over  Five  Hundred  En- 
gravings on  Wood.  In  one  large  and  very  handsome  octavo  volume  of  nearly  1000  pages, 
extra  cloth,  $6  25  ;  leather,  raised  bands,  $7  25.  (Just  Issued.) 

Again,  the  author  gives  us  his  own   practice,  his     and  fairly,  yet  it  is  no  mere  compilation.     The  book 

combines  much  of  the  merit  of  the  rnauual  with  the 
merit  of  the  monograph.  One  may  recognize  in 
almost  every  chapter  of  the  ninety-four  of  which  the 
work  is  made  up  the  acuteness  of  a  surgeon  who  has 


, 

owu  beliefs,  and  illustrates  by  his  own  cases,  or  thos 
treated  in  Guy's  Hospital.     This  feature  .adds  joint 
emphasis,  and  a  solidity  to  his  statements  that  inspire 
confidence.     One  feels  himself  almost  by  the  side  of 


the  surgeon,  seeing  his  work  and  hearing  his  living 
words.  The  views,  etc  ,  of  other  surgeons  are  con- 
sidered calmly  and  fairly,  but  Mr.  Bryant's  are 
adopted.  Thus  the  work  is  not  a  compilation  of 
other  writings;  it  is  not  an  encyclopaedia,  but  the 
plain  statements,  on  practical  points,  of  a  man  who 
has  lived  and  breathed  and  had  his  being  in  the 
richest  surgical  experience.  The  whole  profession 
owe  a  debt  of  gratitude  to  Mr.  Bryant,  for  his  work 
in  their  behalf.  We  are  confident  that  the  American 
profession  will  give  substantial  testimonial  of  their 
feelings  towards  both  author  and  publisher,  by 
speedily  exhausting  this  edition.  We  cordially  and 
heartily  commend  it  to  our  friends,  and  think  that 
no  live  surgeon  can  afford  to  be  without  it  — Detroit 
Review  of  Med.  and  Pharmacy,  August,  1873. 

As  a  manual  of  the  practice  of  surgery  for  the  use 
of  the  studeut,  we  do  not  hesitate  to  pronounce  Mr. 
Bryant's  book  a  first-rate  work.  Mr.  Bryant  has  a 
good  deal  of  the  dogmatic  energy  which  goes  with 
the  clear,  pronounced  opinions  of  a  man  whose  re- 
flections and  experience  have  moulded  a  character 
not  wanting  in  firmness  and  decision.  At  the  same 
time  he  teaches  with  the  enthusiasm  of  one  who  has 
faith  in  his  teaching;  he  speaks  as  one  having  au- 
thority, and  herein  lies  the  charm  and  excellence  of 
his  work.  He  states  the  opinions  of  others  freely 


seen  much,  and  observed  closely,  and  who  gives  forth 
the  results  of  actual  experience.  In  conclusion  we 
repeat  what  we  stated  at  fiivt,  that  Mr.  Bryant's  book 
is  one  which  we  can  conscientiously  recommend  both 
to  practitioners  and  students  as  an  admirable  work. 
— Dublin  Jonrn.  of  Med.  Science,  August,  1873. 

Mr.  Bryant  has  long  been  known  to  the  reading 
portion  of  the  profession  as  an  able,  clear,  and  graphic 
writer  upon  surgical  subjects.  The  volume  before 
us  is  one  eminently  upon  the  practice  of  surgery  and 
not  one  which  treats  at  length  on  surgical  pathology, 
though  the  views  that  are  entertained  upon  this  sub- 
ject are  sufficiently  interspersed  through  the  work 
for  all  practical  purposes.  As  a  text-book  we  cheer- 
fully recommend  it,  feeling  convinced  that,  from  the 
subject-matter,  and  the  concise  and  true  way  Mr. 
Bryant  deals  with  his  subject,  it  will  prove  a  for- 
midable rival  among  the  numerous  surgical  text- 
books which  are  offered  to  the  student.—^.  Y.  Med. 
Record,  June,  1873. 

This  is,  as  the  preface  states,  an  entirely  new  book, 
and  contains  in  a  moderately  condensed  form  all  the 
surgical  information  necessary  to  a  general  practi- 
tioner. It  is  written  in  a  spirit  consistent  with  the 
present  improved  standard  of  medical  and  surgical 
science. — American  Journal  of  Obstetrics,  August, 
1873. 


w 


ELLS  (J.  SOELBERG), 

Professor  of  Ophthalmology  in  King'1 8  College  Hospital,  Ac. 


A  TREATISE  ON  DISEASES  OF  THE  EYE.      Second  Americar, 

from  the  Third  and  Revised  London  Edition,  with  additions;  illustrated  with  numerous 
engravings  on  wood,  and  six  colored  plates.  Together  with  selections  from  the  Test-types 
of  Jaeger  and  Snellen.  In  one  large  and  very  handsome  octavo  volume  of  nearly  800 
pages  ;  cloth,  $5  00  ;  leather,  $8  00.  (Now  Ready.) 

The  continued  demand  for  this  work,  both  in  England  and  this  country,  is  sufficient  evidence 
that  the  author  has  succeeded  in  his  effort  to  supply  within  a  reasonable  compass  a  full  practical 
digest  of  ophthalmology  in  its  most  modern  aspects,  while  the  call  for  repeated  editions  has  en- 
abled him  in  his  revisions  to  maintain  its  position  abreast  of  the  most  recent  investigations  and 
improvements.  In  again  reprinting  it,  every  effort  has  been  made  to  adapt  it  thoroughly  to  the 
•wants  of  the  American  practitioner.  Such  additions  as  seemed  desirable  have  been  introduced 
by  the  editor,  Dr.  I.  Minis  Hays,  and  the  number  of  illustrations  has  been  largely  increased.  The 
importance  of  test-types  as  an  aid  to  diagnosis  is  so  universally  acknowledged  at  the  present  day 
that  it  seemed  essential  to  the  completeness  of  the  work  that  they  should  be  added,  and  as  the 
author  recommends  the  use  of  those  both  of  Jaeger  and  of  Snellen  for  different  purposes,  selec- 
tions have  been  made  from  each,  so  that  the  practitioner  may  have  at  command  all  the  assist- 
ance necessary.  Although  enlarged  by  one  hundred  pages,  it  has  been  retained  at  the  former 
very  moderate  price,  rendering  it  one  of  the  cheapest  volumes  before  the  profession. 
A  few  notices  of  the  previous  edition  are  subjoined. 

found  difficult  to  the  student,  he  has  dwelt  at  length 
and  entered  into  full  explanation.  After  a  careful 
perusal  of  its  contents,  we  can  unhesitatingly  com- 
mend it  to  all'  who  desire  to  consult  a  really  good 


In  this  respect  the  work  before  us  is  of  much  more 
service  to  the  general  practitioner  than  those  heavy 
compilations  which,  in  giving  every  person's  views, 
too  often  neglect  to  specify  those  which  are  most 


accordance  with  the  author's  opinions,  or  in  general  j  work  on  ophhtalmicscience. — Leavenworth Mde.  Her- 
acceptance.  We  have  no  hesitation  in  recommending    aid,  Jan.  1870. 


this  treatise,  as,  on  the  whole,  of  all  English  works 


Without  doubt,  one  of  the  best  works  upon  the  sub 


n  the  subject,  the  one  best  adapted  to  the  wants  of  |  ject  which  has  ever  been  published  ;  it  is  complete  on 
le  general  practitioner.— Edinburgh  Med.  Journal,  |  tjje  suhject  of  which  it  treats,  and  is  a  necessary  work 

for  every  physician  who  attempts  to  treat  diseases  of 


the  ge 
March,  1870. 

A  treatise  of  rare  merit. 


It  is  practical,  compre- 


hensive, and  yet  concise.  Upon  those  subjects  usually 


the  eye— Dominion  Med.  Journal,  Sept.  1869. 


f  A  URENCE  (JOHN  Z.),  F.  R.  C.  S., 

"^~^  Editor  of  the  Ophthalmic  Review,  &c. 

A  HANDY-BOOK  OF   OPHTHALMIC   SURGERY,  for  the  use  of 

Practitioners.     Second  Edition,  revised  and  enlarged.     With  numerous  illustrations.     In 
one  very  handsome  octavo  volume,  extra  cloth,  $3  00.     (Lately  Issued.) 


For  those,  however,  who  must  assume  the  care  of 
diseases  and  injuries  of  the  eye,  and  who  are  too 
much  pressed  for  time  to  study  the  classic  works  on 
the  suhject,  or  those  recently  published  by  Stellwag, 
Wells,  Bader,  and  others,  Mr.  Laurence  will  prove  a 
safe  and  trustworthy  guide.  He  has  described  in  thie 


edition  those  novelties  which  have  secured  the  confi- 
dence of  the  profession  since  the  appearance  of  his 
last.  The  volume  has  been  considerably  enlarged 
and  improved  by  the  revision  and  additions  of  its 
author,  expressly  for  the  American  edition — Am. 
Journ.  Mtd.  Sciences,  Jan.  1870. 


30  HENRY  C.  LEA'S  PUBLICATIONS — (Surgery,  &c.). 


THOMPSON  (SIR  HENRY], 

•*-  Surgeon  and  Professor  of  Clinical  Surgery  to  University  College  Hospital. 

LECTURES  ON  DISEASES  OF  THE  URINARY  ORGANS.    With 

illustrations  on  wood.     In  one  neat  octavo  volume,  extra  cloth.     $2  25. 


These  lectures  stand  the  severe  test.  They  are  in- 
structive without  being  tedious,  and  simple  without 
being  diffuse;  and  they  include  many  of  those  prac- 


tical hints  so  useful  for  the  student,  and  even  more 
valuable  to  the  voting  practitioner. — Edinburgh  Med. 
Journal,  April,' 1869. 


JDF  THE  SAME  AUTHOR. 

ON  THE  PATHOLOGY  AND  TREATMENT  OF  STRICTURE  OF 

THE  URETHKA  AND  URINARY  FISTULA.  With  plates  and  wood-cuts.  From  the 
third  and  revised  English  edition.  In  one  very  handsome  octavo  volume,  extra  cloth,  $3  50. 
(Lately  Published.) 

This  classical  work  has  so  long  been  recognized  as  a  standard  authority  on  its  perplexing  sub- 
jects that  it  should  be  rendered  accessible  to  the  American  profession.  Having  enjoyed  the 
advantage  of  a  revision  at  the  hands  of  the  author  within  a  few  months,  it  will  be  found  to  present 
his  latest  views  and  to  be  on  a  level  with  the  most  recent  advances  of  surgical  science. 

With  a  work  accepted  as  the  authority  upon  the  I  ably  known  by  the  profession  as  this  before  us,  must 
subjects  of  which  it  treats,  an  extended  notice  would  |  create  a  demand  for  it  from  those  who  would  keep 
be  a  work  of  supererogation.  The  simple  announce-  I  themselves  well  up  in  this  department  of  surgery. — 
ment  of  another  edition  of  a  work  so  well  and  favor-  |  St.  Louis  Med.  Archives,  Feb.  1870. 


£ Y  THE  SAME  AUTHOR.     (Just  Ready.) 

THE  DISEASES    OF   THE   PROSTATE,  THEIR   PATHOLOGY 

AND  TREATMENT.     Fourth  Edition,  Revised.     In  one  very  handsome  octavo  volume  of 

355  pages,  with  thirteen  piates,  plain  and  colored,  and  illustrations  on  wood.     Cloth,  $3  75. 

This  work  is  recognized  in  England  as  the  leading  authority  on  its  subject,  and  in  presenting 

it  to  the  American  profession,  it  is  hoped  that  it  will  be  found   a  trustworthy  and  satisfactory 

guide  in  the  treatment  of  an  obscure  and  important  class  of  affections. 


WALES  (PHILIP  £.),  M.D.,  Surgeon  U.  S.  N. 


MECHANICAL  THERAPEUTICS:  a  Practical  Treatise  on  Surgical 

Apparatus,  Appliances,  and  Elementary  Operations  :  embracing  Minor  Surgery,  Band- 
aging, Orthopraxy,  and  the  Treatment  of  Fractures  and  Dislocations.  With  six  hundred 
and  forty-two  illustrations  on  wood.  In  one  large  and  handsome  octavo  volume  of  about 
700  pages :  extra  cloth,  $5  75 ;  leather,  $6  75. 


fTAYLOR  (ALFRED  S.),  M.D., 

•*-  Lecturer  on  Med.  Jurisp.  and  Chemistry  in  Guy's  Hospital. 

MEDICAL  JURISPRUDENCE.     Seventh  American  Edition.     Edited 

by  JOHN  J.  REESE,  M.D.,  Prcf.  of  Med.  Jurisp.  in  the  Univ.  of  Penn.  In  one  large 
octavo  volume.  Cloth,  $5  00  ;  leather,  $6  00.  (Now  Ready.) 

In  preparing  for  the  press  this  seventh  American  edition  of  the  "  Manual  of  Medical  Jurispru- 
dence" the  editor  has,  through  the  courtesy  of  Dr.  Taylor,  enjoyed  the  very  great  advantage  of 
consulting  the  sheets  of  the  new  edition  of  the  author's  larger  work,  "  The  Principles  and  Prac- 
tice of  Medical  Jurisprudence,"  which  is  now  ready  for  publication  in  London.  This  has  enabled 
him  to  introduce  the  author's  latest  views  upon  the  topics  discussed,  which  are  believed  to  bring 
the  work  fully  up  to  the  present  time. 

The  notes  of  the  former  editor,  Dr.  Hartshorne,  as  also  the  numerous  valuable  references  to 
American  practice  and  decisions  by  his  successor,  Mr.  Penrose,  have  been  retained,  with  but  few 
slight  exceptions ;  they  will  be  found  inclosed  in  brackets,  distinguished  by  the  letters  (H.)  and 
(P.).  The  additions  made  by  the  present  editor,  from  the  material  at  his  command,  amount  to 
about  one  hundred  pages;  and  his  own  notes  are  designated  by  the  letter  (K.). 

Several  subjects,  not  treated  of  in  the  former  edition,  have  been  noticed  in  the  present  one, 
and  the  work,  it  is  hoped,  will  be  found  to  merit  a  continuance  of  the  confidence  which  it  has  so 
long  enjoyed  as  a  standard  authority. 

£Y  THE  SAME  AUTHOR.     (Note  Ready.) 

THE  PRINCIPLES  AND  PRACTICE  OF  MEDICAL  JURISPRU- 

DENCE.     Second    Edition,   Revised,  with   numerous  Illustrations.     In    two   very  large 

octavo  volumes,  cloth,  $10  00;  leather,  $12  00. 

This  great  work  is  now  recognized  in  England  as  the  fullest  and  most  authoritative  treatise  on 
every  department  of  its  important  subject.  In  laying  it,  in  its  improved  form,  before  the  Ameri- 
can profession,  the  publisher  trusts  that  jl  will  assume  the  same  position  in  this  country. 


HENRY  C.  LEA'S  PUBLICATIONS— (Psychological  Medicine,  &c.).      31 
fTUKE  (DANIEL  HACK],  M.D., 

-L  Joint  author  of  "  The  Manual  of  Psychological  Medicine,"  &c. 

ILLUSTRATIONS  OF  THE  INFLUENCE  OF  THE  MIND  UPON 

THE  BODY  IN  HEALTH  AND  DISEASE.  Designed  to  illustrate  the  Action  of  toe 
Imagination.  In  one  handsome  octavo  volume  of  416  pages,  extra  cloth,  $3  25.  (Now 
Ready.) 

The  object  of  the  author  in  this  work  has  been  to  show  not  only  the  effect  of  the  mind  in  caus- 
ing and  intensifying  disease,  but  also  its  curative  influence,  and  the  use  which  may  be  made  of 
the  imagination  and  the  emotions  as  therapeutic  agents.  Scattered  facts  bearing  upon  this  sub- 
ject have  long  been  familiar  to  the  profession,  but  no  attempt  has  hitherto  been  made  to  collect 
and  systematize  them  so  as  to  render  them  available  to  the  practitioner,  by  establishing  the  seve- 
ral phenomena  upon  a  scientific  basis.  In  the  endeavor  thus  to  convert  to  the  use  of  legitimate 
medicine  the  means  which  have  been  employed  so  successfully  in  many  systems  of  quackery,  the 
author  has  produced  a  work  of  the  highest  freshness  and  interest  as  well  as  of  permanent  value. 

&LANDFORD  (G.  FIELDING],  M.  D.,  F.  R.  C  P., 

-*-'  Lecturer  on  Psychological  Medicine  at  the  School  of  St.  George's  Hospital,  Ac. 

INSANITY  AND  ITS  TREATMENT:   Lectures  on  the  Treatment, 

Medical  and   Legal,  of  Insane  Patients.     With  a  Summary  of  the  Laws  in  force  in  the 
United  States  on  the  Confinement  of  the  Insane.     By  ISAAC  RAY,  M.  D.     In  one  very 
handsome  octavo  volume  of  471  pages:  extra  cloth,  $3  25.     (Just  Issued.) 
This  volume  is  presented  to  meet  the  want,  so  frequently  expressed,  of  a  comprehensive  trea- 
tise, in  moderate  compass,  on  the  pathology,  diagnosis,  and  treatment  of  insanity.    To  render  it  of 
more  value  to  the  practitioner  in  this  country,  Dr.  Ray  has  added  an  appendix  which  affords  in- 
formation, not  elsewhere  to  be  found  in  so  accessible  a  form,  to  physicians  who  may  at  any  moment 
be  called  upon  to  take  action  in  relation  to  patients. 

It  satisfies  a  want  which  must  have  been  sorely  j  actually  seen  in  practice  and  the  appropriate  treat- 
felt  by  the  busy  general  practitioner^  of  this  country.  I  meat  for  them,  we  find  in  Dr.  Blaudford's  work  a 
It  takes  the  form  of  a  manual  of  clinical  description  j  considerable  advance  over  previous  writings  on  the 
of  the  various  forms  of  insanity,  with  a  description  subject.  His  pictures  of  the  various  forms  of  mental 
of  the  mode  of  examining  persons  suspected  of  in-  j  disease  are  so  clear  and  good  that  no  reader  cau  tail 
sanity.  We  call  particular  attention  to  this  feature  j  to  be  struck  with  their  superiority  to  those  given  in 
of  the  book,  as  giving  it  a  unique  value  to  the  gene-  |  ordinary  manuals  in  the  English  language  or  (so  far 


ral  practitioner.    If  we  pass  from  theoretical  conside- 
rations to  descriptions  of  the  varieties  of  insanity  as 


as  our  own  reading  extends)  in  any  other. — London 
Practitioner,  Feb.  1871. 


WINSLOW  (FORBES),  M.D.,  D.C.L,,  £-c. 

ON  OBSCURE  DISEASES  OF  THE  BRAIN  AND  DISORDERS 

OF  THE  MIND;  their  incipient  Symptoms,  Pathology,  Diagnosis,  Treatment,  and  Pro- 
phylaxis. Second  American,  from  the  third  and  revised  English  edition.  In  one  handsome 
octavo  volume  of  nearly  600  pages,  extra  cloth.  $4  25. 

T  EA  (HENRY  C.). 

SUPERSTITION    AND    FORCE:    ESSAYS    ON    THE   WAGER   OF 

LAW,  THE  WAGER  OF  BATTLE,  THE  ORDEAL,  AND  TORTURE.  Second  Edition, 
Enlarged.  In  one  handsome  volume  royal  I2mo.  of  nearly  500  pages  j  extra  cloth,  $2  75. 
(Lately  Published.) 


We  kuow  of  no  single  work  which  contains,  in  so 
•mall  a  compass,  so  much  illustrative  of  the  strangest 
operations  of  the  human  mind.  Foot-notes  give  the 


interesting  phases  of  human  society  and  progress.  . 
The  fulness  and  breadth  with  which  he  has  carried 
out  his  comparative  survey  of  this  repulsive  field  of 
history  [Torture],  are  such  as  to  preclude  our  duiug 
justice  to^the  work  within  our  present  limits.     But 

r<Tread7his "book  and  ponder  its  teachings.—  Chicago     here,  as  throughout  the  volume,  there  will  be  found 
M^d.  Journal,  Aug.  1870.  j  a  wealth  of  illustration  aud  ^critical  ^grasp^of  the 

As  a  work  of  curious  inquiry  on  certain  outlying 


authoritv  for  each  statement,  showing  vast  research  history  [Torture],  are  such  as  to  preclude  our  dm 
and  wonderful  industry.  We  advise  our  confreres  [justice  to^the  work  within  our  present  limits.  I 
to  read  this  book  and  ponder  its  teachings.—  Chicago  \  here,  as  throughout  the  volume,  there  will  be  fou 


points  of  obsolete  law,  "Superstition  and  Force"  is 
one  of  the  most  remarkable  books  we  have  met  with. 
—London  Atfienceum,  Nov.  3,  18(56. 

He  has  thrown  a  great  deal  of  light  upon  what  must 
be  regarded  as  one  of  the  most  instructive  as  well  as 


Lea's  labors  of  sterling  value  to  the  historical  stu- 
dent.— London  Saturday  Review,  Oct.  8,  1870. 

As  a  book  of  ready  reference  on  the  subject,  it  is  of 
the  highest  value.—  Westminster  Review,  Oct.  1867. 


or  THE  SAME  AUTHOR.    (Late  y  Published.) 

**  STUDIES  IN  CHURCH  HISTORY— THE  RISE  OF   THE  TEM- 
PORAL POWER— BENEFIT  OF  CLERGY— EXCOMMUNICATION.   In  one  large  royal 
12tno.  volume  of  516  pp.  extra  cloth.     $2  75. 
The  story  was  never  told  more   calmly  or  with    literary  phenomenon  that  the  head  of  one  of  the  first 


greater  learning  or  wiser  thought.  We  doubt,  indeed, 
if  auy  other  study  of  this  field  can  be  compared  with 
tins  for  clearness,  accuracy,  and  power.  —  Chicago 
Examiner,  Dec.  1870. 

Mr.  Lea's  latest  work,  "SfudiesinChnrch  History,' 


American  houses  is  also  the  writer  of  some  of  its  most 
original  books. — London,  Athenceum,  Jan.  7,  1871. 

Mr.  Lea  has  done  great  honor  to  himself  aud  this 
country  by  the  admirable  works  he  has  written  on 
ecclesiologicalaud  cognate  subjects.  We  have  already 
had  occasion  to  commend  his  "Superstition  and 


fnllv  sustains  the  promise  uf  the  first.  It  deals  with  had  occasion  to  commend  his  "Superstition  and 
three  subjects— the  Temporal  Power,  Benefit  of  Force"  and  his  "  History  of  Sacerdotal  Celibacy." 
Tlpnrv  and  Excommunication,  the  record  of  which  The  present  volume  is  fully  as  admirable  ia  its  ine- 

a  peculiar  importance  for  the  English  student,  and  j  thod  of  dealing  with  topics  and  in  the  thoroughness— 
i*  a  chapter  on  Ancient  Law  likely  to  be  regarded  as  I  a  quality  so  frequently  .acking  in  American  authors— 

t     We  can  hardly  pass  from  our  mention  of  such  .  with  which  they  are  investigated.— tf.  Y.  Journal  of 
works  as  these-with  which   that   on    "Sacerdotal  \  Psychol  Medicine,  July,  1870. 
Celibacy"  should  be  included— without  noting  the  I 


32 


HENRY  C.  LEA'S  PUBLICATION  s. 


INDEX    TO    CATALOGUE. 


PAGE 

American  Journal  of  the  Medical  Sciences  .      1 

American  Chemist  (The) 11 

Abstract,  Half-Yearly,  of  the  Med  Sciences  .  3 
Anatomical  Atlas,  by  Smith  and  Homer  .  .  6 
Anderson  on  Diseases  of  the  Skin  .  .  .20 
Ashton  on  the  Rectum  and  Anus  .  .  .  .28 

Attfield's  Chemistry 10 

Ashwell  on  Diseases  of  Females  .        .        .        .23 

Ashhurst's  Surgery 27 

Barnes  on  Diseases  of  Women  .  .  .  .23 
Bellamy's  Surgical  Anatomy  ....  7 

Bryant's  Practical  Surgery 29 

Bloxam's  Chemistry        • 10 

blandford  on  Insanity 31 

Basham  on  Renal  Diseases     .....     18 

Brinton  on  the  Stomach 16 

Bigelow  on  the  Hip          ....  .28 

Barlow's  Practice  of  Medicine  .  .  .  .  14 
Bowman's  (John  E.)  Practical  Chemistry  .  .  11 
Bowman's  (John  E.)  Medical  Chemistry  .  .  il 

Buckler  on  Bronchitis 17 

Bumstead  on  Venereal 19 


PAGE 

.  IS 
.  8 
.  11 
.  31 
.  31 
.  18 
.  25 

La  Roche  on  Yellow  Fever 14 

17 
23 


Jones  (C.  Handfleld)  on  Nervous  Disorders 

Kirkes'  Physiology 

Kaapp's  Chemical  Technology 

Lea's  Superstition  and  Force 

Lea's  Studies  in  Church  History    . 

Lincoln  on  Electro  Therapeutics    . 

Leishman's  Midwifery 


La  Roche  on  Pneumonia,  &c. 

Laurence  and  Moon's  Ophthalmic  Surgery    . 

Lawson  on  the  Eye 

Laycock  on  Medical  Observation  . 
Lehmann's  Physiological  Chemi.stry,  2  vols. 
Lehmann's  Chemical  Physiology  . 
Ludlow's  Manual  of  Examinations 
Lyons  on  Fever 


Maclise's  Surgical  Anatomy 7 

Marshall's  Physiology 
Medical  News  and  Libi 


>rary 


23 


Bumstead  and  Cullerier's  Atlas  of  Venereal 
Carpenter's  Human  Physiology    . 
Carpenter's  Comparative  Physiology   . 
Carpenter  on  the  Use  and  Abuse  of  Alcohol 
Carson's  Synopsis  of  Materia  Medica    . 
Chambers  on  the  Indigestions 
Chambers's  Restorative  Medicine  .        . 

Christison  and  Griffith's  Dispensatory 
Churchill's  System  of  Midwifery  . 
Churchill  on  Puerperal  Fever 
Condie  on  Diseases  of  Children     . 
Cooper's  (B.  B.)  Lectures  on  Surgery    . 
Cullerier's  Atlas  of  Venereal  Diseases 
Cyclopedia  of  Practical  Medicine  . 
Dalton's  Human  Physiology  .... 
De  Jongh  on  Cod-Liver  Oil     .... 
D  e wees' s  System  of  Midwifery 
Dewees  on  Diseases  of  Females     . 
Dewees  on  Diseases  of  Children    . 
Druitt's  Modern  Surgery        .        .    _    . 
Dunglison's  Medical  Dictionary    . 
Dunglison's  Human  Physiology    . 
Dunglison  on  New  Remedies 
Ellis's  Medical  Formulary,  by  Smith   . 
Erichsen's  System  of  Surgery 

Fenwick's  Diagnosis 

Flint  on  Respiratory  Organs  .... 
Flint  on  the  Heart 


Fownes's  Elementary  Chemistry  . 
Fox  on  Diseases  of  the  Stomach    . 

Fuller  on  tlie  Lungs,  &c 

Green's  Pathology  and  Morbid  Anatomy     . 

Gibson's  Surgery     

G  luge's  Pathological  Histology,  by  Leidy    . 
Galloway's  Qualitative  Analysis  . 
Gray's  Anatomy      .        .         . 
Griffith's  (R.  E.)  Universal  Formulary 
Gross  on  Foreign  Bodies  in  Air-Passages 
Gross's  Principles  and  Practice  of  Surgery  . 
Gross's  Pathological  Anatomy        .... 
Guersant  on  Surgical  Diseases  of  Children   . 
Hamilton  on  Dislocations  and  Fractures 
Hartshorne's  Essentials  of  Medicine     . 
Hartshorne's  Conspectus  of  the  Medical  Sciences 
Hartshorne's  Anatomy  and  Physiology 
Heath's  Practical  Anatomy    .         .        .        . 
Boblyn's  Medical  Dictionary        .... 

Hodge  on  Women 

Hodge's  Obstetrics 

Hodges'  Practical  Dissections        .... 
Holland's  Medical  Notes  and  Reflections 
Homer's  Anatomy  and  Histology 

Hudson  on  Fevers 

Hill  on  Venereal  Diseases 19 

Hillier's  Handbook  of  Skin  Diseases  .        .    20 

Jones  and  Sieveking's  Pathological  Anatomy     .    14 


Meigs's  Lectures  on  Diseases  of  Women 

Meigs  on  Puerperal  Fever      ..... 

Miller's  Practice  of  Surgery 

19  |  Miller's  Principles  of  Surgery        .... 
8  |  Montgomery  on  Pregnancy    ..... 
8  :  Neill  and  Smith's  Compendium  of  Med.  Science  . 

13  I  Neligan's  Atlas  of  Diseases  of  the  Skin 

13     Neligan  on  Diseases  of  the  Skin     .... 

15     Obstetrical  Journal 

15     Odling's  Practical  Chemistry        .... 

13    Pavy  on  Digestion 

25     Pavy  on  Food 

23    Prize  Essays  on  Consumption         .... 
21     Parrish's  Practical  Pharmacy        .... 

Pirrie's  System  of  Surgery 

Pereira's  Mat.  Medica  and  Therapeutics,  abridged 

Quain  and  Sharpey's  Anatomy,  by  Leidy    . 

Roberts  on  Urinary  Diseases 

Ramsbotham  on  Parturition 

Rigby's  Midwifery 

Royle's  Materia  Medica  and  Therapeutics    . 

20  j  Swayne's  Obstetric  Apliurisms      .... 
28    Sargent's  Minor  Surgery 

Sharpey  and  Quain's  Anatomy,  by  Leidy    . 

Skey's  Operative  Surgery 

Slade  on  Diphtheria 

Smith  (J.  L.)  on  Children 

Smith  (H.  H.)  and  Homer's  Anatomical  Atlas 
Smith  (Edward)  on  Consumption  .... 
Smith  on  Wasting  Diseases  of  Children 

Still6's  Therapeutics 

Sturges  on  Clinical  Medicine          .... 
Tanner's  Manual  of  Clinical  Medicine  . 

Tanner  on  Pregnancy 

Taylor's  Medical  Jurisprudence     .... 
Taylor's  Principles  and  Practice  of  Med   Jurisp. 
Tuke  on  the  Influence  of  the  Mind 
Thomas  on  Diseases  of  Females    .... 
Thompson  on  Urinary  Organs        .... 

Thompson  on  Stricture 

Thompson  on  the  Prostate      ..... 

Todd  on  Acute  Diseases 

Wales  on  Surgical  Operations        .... 

Walshe  on  the  Heart 

Watson's  Practice  of  Physic 

Wells  on  the  Eye 

West  on  Diseases  of  Females         .... 
West  on  Diseases  of  Children        .... 
West  on  Nervous  Disorders  of  Children 
West  on  Ulceration  of  Os  Uteri      .... 
What  to  Observe  in  Medical  Cases 

Williams  on  Consumption 17 

Wilson  s  Human  Anatomy 7 

Wilson  on  Diseases  of  the  Skin  ....  20 
Wilson's  Hates  on  Diseases  of  the  Skin  .  .  20 
Wilson's  Handbook  of  Cutaneous  Medicine  .  20 
Winslow  on  Brain  and  Mind  .  .  .  .31 
Wohler's  Organic  Chemistry  ....  11 

Winckel  on  Childbed 24 

Zeissl  on  Venereal 19 


For  "THE  AMERICAN  CHEMIST"  FIVE  DOLLARS  a  year,  see  p.  11. 
For  "  THE  OBSTETRICAL  JOURNAL"  FIVE  DOLLARS  a  year,  see  p.  22. 


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